xref: /linux/fs/xfs/libxfs/xfs_bmap.c (revision 0e862838f290147ea9c16db852d8d494b552d38d)
1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4   * All Rights Reserved.
5   */
6  #include "xfs.h"
7  #include "xfs_fs.h"
8  #include "xfs_shared.h"
9  #include "xfs_format.h"
10  #include "xfs_log_format.h"
11  #include "xfs_trans_resv.h"
12  #include "xfs_bit.h"
13  #include "xfs_sb.h"
14  #include "xfs_mount.h"
15  #include "xfs_defer.h"
16  #include "xfs_dir2.h"
17  #include "xfs_inode.h"
18  #include "xfs_btree.h"
19  #include "xfs_trans.h"
20  #include "xfs_alloc.h"
21  #include "xfs_bmap.h"
22  #include "xfs_bmap_util.h"
23  #include "xfs_bmap_btree.h"
24  #include "xfs_rtalloc.h"
25  #include "xfs_errortag.h"
26  #include "xfs_error.h"
27  #include "xfs_quota.h"
28  #include "xfs_trans_space.h"
29  #include "xfs_buf_item.h"
30  #include "xfs_trace.h"
31  #include "xfs_attr_leaf.h"
32  #include "xfs_filestream.h"
33  #include "xfs_rmap.h"
34  #include "xfs_ag.h"
35  #include "xfs_ag_resv.h"
36  #include "xfs_refcount.h"
37  #include "xfs_icache.h"
38  #include "xfs_iomap.h"
39  
40  struct kmem_cache		*xfs_bmap_intent_cache;
41  
42  /*
43   * Miscellaneous helper functions
44   */
45  
46  /*
47   * Compute and fill in the value of the maximum depth of a bmap btree
48   * in this filesystem.  Done once, during mount.
49   */
50  void
51  xfs_bmap_compute_maxlevels(
52  	xfs_mount_t	*mp,		/* file system mount structure */
53  	int		whichfork)	/* data or attr fork */
54  {
55  	uint64_t	maxblocks;	/* max blocks at this level */
56  	xfs_extnum_t	maxleafents;	/* max leaf entries possible */
57  	int		level;		/* btree level */
58  	int		maxrootrecs;	/* max records in root block */
59  	int		minleafrecs;	/* min records in leaf block */
60  	int		minnoderecs;	/* min records in node block */
61  	int		sz;		/* root block size */
62  
63  	/*
64  	 * The maximum number of extents in a fork, hence the maximum number of
65  	 * leaf entries, is controlled by the size of the on-disk extent count.
66  	 *
67  	 * Note that we can no longer assume that if we are in ATTR1 that the
68  	 * fork offset of all the inodes will be
69  	 * (xfs_default_attroffset(ip) >> 3) because we could have mounted with
70  	 * ATTR2 and then mounted back with ATTR1, keeping the i_forkoff's fixed
71  	 * but probably at various positions. Therefore, for both ATTR1 and
72  	 * ATTR2 we have to assume the worst case scenario of a minimum size
73  	 * available.
74  	 */
75  	maxleafents = xfs_iext_max_nextents(xfs_has_large_extent_counts(mp),
76  				whichfork);
77  	if (whichfork == XFS_DATA_FORK)
78  		sz = XFS_BMDR_SPACE_CALC(MINDBTPTRS);
79  	else
80  		sz = XFS_BMDR_SPACE_CALC(MINABTPTRS);
81  
82  	maxrootrecs = xfs_bmdr_maxrecs(sz, 0);
83  	minleafrecs = mp->m_bmap_dmnr[0];
84  	minnoderecs = mp->m_bmap_dmnr[1];
85  	maxblocks = howmany_64(maxleafents, minleafrecs);
86  	for (level = 1; maxblocks > 1; level++) {
87  		if (maxblocks <= maxrootrecs)
88  			maxblocks = 1;
89  		else
90  			maxblocks = howmany_64(maxblocks, minnoderecs);
91  	}
92  	mp->m_bm_maxlevels[whichfork] = level;
93  	ASSERT(mp->m_bm_maxlevels[whichfork] <= xfs_bmbt_maxlevels_ondisk());
94  }
95  
96  unsigned int
97  xfs_bmap_compute_attr_offset(
98  	struct xfs_mount	*mp)
99  {
100  	if (mp->m_sb.sb_inodesize == 256)
101  		return XFS_LITINO(mp) - XFS_BMDR_SPACE_CALC(MINABTPTRS);
102  	return XFS_BMDR_SPACE_CALC(6 * MINABTPTRS);
103  }
104  
105  STATIC int				/* error */
106  xfs_bmbt_lookup_eq(
107  	struct xfs_btree_cur	*cur,
108  	struct xfs_bmbt_irec	*irec,
109  	int			*stat)	/* success/failure */
110  {
111  	cur->bc_rec.b = *irec;
112  	return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
113  }
114  
115  STATIC int				/* error */
116  xfs_bmbt_lookup_first(
117  	struct xfs_btree_cur	*cur,
118  	int			*stat)	/* success/failure */
119  {
120  	cur->bc_rec.b.br_startoff = 0;
121  	cur->bc_rec.b.br_startblock = 0;
122  	cur->bc_rec.b.br_blockcount = 0;
123  	return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
124  }
125  
126  /*
127   * Check if the inode needs to be converted to btree format.
128   */
129  static inline bool xfs_bmap_needs_btree(struct xfs_inode *ip, int whichfork)
130  {
131  	struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
132  
133  	return whichfork != XFS_COW_FORK &&
134  		ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
135  		ifp->if_nextents > XFS_IFORK_MAXEXT(ip, whichfork);
136  }
137  
138  /*
139   * Check if the inode should be converted to extent format.
140   */
141  static inline bool xfs_bmap_wants_extents(struct xfs_inode *ip, int whichfork)
142  {
143  	struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
144  
145  	return whichfork != XFS_COW_FORK &&
146  		ifp->if_format == XFS_DINODE_FMT_BTREE &&
147  		ifp->if_nextents <= XFS_IFORK_MAXEXT(ip, whichfork);
148  }
149  
150  /*
151   * Update the record referred to by cur to the value given by irec
152   * This either works (return 0) or gets an EFSCORRUPTED error.
153   */
154  STATIC int
155  xfs_bmbt_update(
156  	struct xfs_btree_cur	*cur,
157  	struct xfs_bmbt_irec	*irec)
158  {
159  	union xfs_btree_rec	rec;
160  
161  	xfs_bmbt_disk_set_all(&rec.bmbt, irec);
162  	return xfs_btree_update(cur, &rec);
163  }
164  
165  /*
166   * Compute the worst-case number of indirect blocks that will be used
167   * for ip's delayed extent of length "len".
168   */
169  STATIC xfs_filblks_t
170  xfs_bmap_worst_indlen(
171  	xfs_inode_t	*ip,		/* incore inode pointer */
172  	xfs_filblks_t	len)		/* delayed extent length */
173  {
174  	int		level;		/* btree level number */
175  	int		maxrecs;	/* maximum record count at this level */
176  	xfs_mount_t	*mp;		/* mount structure */
177  	xfs_filblks_t	rval;		/* return value */
178  
179  	mp = ip->i_mount;
180  	maxrecs = mp->m_bmap_dmxr[0];
181  	for (level = 0, rval = 0;
182  	     level < XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK);
183  	     level++) {
184  		len += maxrecs - 1;
185  		do_div(len, maxrecs);
186  		rval += len;
187  		if (len == 1)
188  			return rval + XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) -
189  				level - 1;
190  		if (level == 0)
191  			maxrecs = mp->m_bmap_dmxr[1];
192  	}
193  	return rval;
194  }
195  
196  /*
197   * Calculate the default attribute fork offset for newly created inodes.
198   */
199  uint
200  xfs_default_attroffset(
201  	struct xfs_inode	*ip)
202  {
203  	if (ip->i_df.if_format == XFS_DINODE_FMT_DEV)
204  		return roundup(sizeof(xfs_dev_t), 8);
205  	return M_IGEO(ip->i_mount)->attr_fork_offset;
206  }
207  
208  /*
209   * Helper routine to reset inode i_forkoff field when switching attribute fork
210   * from local to extent format - we reset it where possible to make space
211   * available for inline data fork extents.
212   */
213  STATIC void
214  xfs_bmap_forkoff_reset(
215  	xfs_inode_t	*ip,
216  	int		whichfork)
217  {
218  	if (whichfork == XFS_ATTR_FORK &&
219  	    ip->i_df.if_format != XFS_DINODE_FMT_DEV &&
220  	    ip->i_df.if_format != XFS_DINODE_FMT_BTREE) {
221  		uint	dfl_forkoff = xfs_default_attroffset(ip) >> 3;
222  
223  		if (dfl_forkoff > ip->i_forkoff)
224  			ip->i_forkoff = dfl_forkoff;
225  	}
226  }
227  
228  #ifdef DEBUG
229  STATIC struct xfs_buf *
230  xfs_bmap_get_bp(
231  	struct xfs_btree_cur	*cur,
232  	xfs_fsblock_t		bno)
233  {
234  	struct xfs_log_item	*lip;
235  	int			i;
236  
237  	if (!cur)
238  		return NULL;
239  
240  	for (i = 0; i < cur->bc_maxlevels; i++) {
241  		if (!cur->bc_levels[i].bp)
242  			break;
243  		if (xfs_buf_daddr(cur->bc_levels[i].bp) == bno)
244  			return cur->bc_levels[i].bp;
245  	}
246  
247  	/* Chase down all the log items to see if the bp is there */
248  	list_for_each_entry(lip, &cur->bc_tp->t_items, li_trans) {
249  		struct xfs_buf_log_item	*bip = (struct xfs_buf_log_item *)lip;
250  
251  		if (bip->bli_item.li_type == XFS_LI_BUF &&
252  		    xfs_buf_daddr(bip->bli_buf) == bno)
253  			return bip->bli_buf;
254  	}
255  
256  	return NULL;
257  }
258  
259  STATIC void
260  xfs_check_block(
261  	struct xfs_btree_block	*block,
262  	xfs_mount_t		*mp,
263  	int			root,
264  	short			sz)
265  {
266  	int			i, j, dmxr;
267  	__be64			*pp, *thispa;	/* pointer to block address */
268  	xfs_bmbt_key_t		*prevp, *keyp;
269  
270  	ASSERT(be16_to_cpu(block->bb_level) > 0);
271  
272  	prevp = NULL;
273  	for( i = 1; i <= xfs_btree_get_numrecs(block); i++) {
274  		dmxr = mp->m_bmap_dmxr[0];
275  		keyp = XFS_BMBT_KEY_ADDR(mp, block, i);
276  
277  		if (prevp) {
278  			ASSERT(be64_to_cpu(prevp->br_startoff) <
279  			       be64_to_cpu(keyp->br_startoff));
280  		}
281  		prevp = keyp;
282  
283  		/*
284  		 * Compare the block numbers to see if there are dups.
285  		 */
286  		if (root)
287  			pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, i, sz);
288  		else
289  			pp = XFS_BMBT_PTR_ADDR(mp, block, i, dmxr);
290  
291  		for (j = i+1; j <= be16_to_cpu(block->bb_numrecs); j++) {
292  			if (root)
293  				thispa = XFS_BMAP_BROOT_PTR_ADDR(mp, block, j, sz);
294  			else
295  				thispa = XFS_BMBT_PTR_ADDR(mp, block, j, dmxr);
296  			if (*thispa == *pp) {
297  				xfs_warn(mp, "%s: thispa(%d) == pp(%d) %Ld",
298  					__func__, j, i,
299  					(unsigned long long)be64_to_cpu(*thispa));
300  				xfs_err(mp, "%s: ptrs are equal in node\n",
301  					__func__);
302  				xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
303  			}
304  		}
305  	}
306  }
307  
308  /*
309   * Check that the extents for the inode ip are in the right order in all
310   * btree leaves. THis becomes prohibitively expensive for large extent count
311   * files, so don't bother with inodes that have more than 10,000 extents in
312   * them. The btree record ordering checks will still be done, so for such large
313   * bmapbt constructs that is going to catch most corruptions.
314   */
315  STATIC void
316  xfs_bmap_check_leaf_extents(
317  	struct xfs_btree_cur	*cur,	/* btree cursor or null */
318  	xfs_inode_t		*ip,		/* incore inode pointer */
319  	int			whichfork)	/* data or attr fork */
320  {
321  	struct xfs_mount	*mp = ip->i_mount;
322  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
323  	struct xfs_btree_block	*block;	/* current btree block */
324  	xfs_fsblock_t		bno;	/* block # of "block" */
325  	struct xfs_buf		*bp;	/* buffer for "block" */
326  	int			error;	/* error return value */
327  	xfs_extnum_t		i=0, j;	/* index into the extents list */
328  	int			level;	/* btree level, for checking */
329  	__be64			*pp;	/* pointer to block address */
330  	xfs_bmbt_rec_t		*ep;	/* pointer to current extent */
331  	xfs_bmbt_rec_t		last = {0, 0}; /* last extent in prev block */
332  	xfs_bmbt_rec_t		*nextp;	/* pointer to next extent */
333  	int			bp_release = 0;
334  
335  	if (ifp->if_format != XFS_DINODE_FMT_BTREE)
336  		return;
337  
338  	/* skip large extent count inodes */
339  	if (ip->i_df.if_nextents > 10000)
340  		return;
341  
342  	bno = NULLFSBLOCK;
343  	block = ifp->if_broot;
344  	/*
345  	 * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
346  	 */
347  	level = be16_to_cpu(block->bb_level);
348  	ASSERT(level > 0);
349  	xfs_check_block(block, mp, 1, ifp->if_broot_bytes);
350  	pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);
351  	bno = be64_to_cpu(*pp);
352  
353  	ASSERT(bno != NULLFSBLOCK);
354  	ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);
355  	ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);
356  
357  	/*
358  	 * Go down the tree until leaf level is reached, following the first
359  	 * pointer (leftmost) at each level.
360  	 */
361  	while (level-- > 0) {
362  		/* See if buf is in cur first */
363  		bp_release = 0;
364  		bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
365  		if (!bp) {
366  			bp_release = 1;
367  			error = xfs_btree_read_bufl(mp, NULL, bno, &bp,
368  						XFS_BMAP_BTREE_REF,
369  						&xfs_bmbt_buf_ops);
370  			if (error)
371  				goto error_norelse;
372  		}
373  		block = XFS_BUF_TO_BLOCK(bp);
374  		if (level == 0)
375  			break;
376  
377  		/*
378  		 * Check this block for basic sanity (increasing keys and
379  		 * no duplicate blocks).
380  		 */
381  
382  		xfs_check_block(block, mp, 0, 0);
383  		pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
384  		bno = be64_to_cpu(*pp);
385  		if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbno(mp, bno))) {
386  			error = -EFSCORRUPTED;
387  			goto error0;
388  		}
389  		if (bp_release) {
390  			bp_release = 0;
391  			xfs_trans_brelse(NULL, bp);
392  		}
393  	}
394  
395  	/*
396  	 * Here with bp and block set to the leftmost leaf node in the tree.
397  	 */
398  	i = 0;
399  
400  	/*
401  	 * Loop over all leaf nodes checking that all extents are in the right order.
402  	 */
403  	for (;;) {
404  		xfs_fsblock_t	nextbno;
405  		xfs_extnum_t	num_recs;
406  
407  
408  		num_recs = xfs_btree_get_numrecs(block);
409  
410  		/*
411  		 * Read-ahead the next leaf block, if any.
412  		 */
413  
414  		nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
415  
416  		/*
417  		 * Check all the extents to make sure they are OK.
418  		 * If we had a previous block, the last entry should
419  		 * conform with the first entry in this one.
420  		 */
421  
422  		ep = XFS_BMBT_REC_ADDR(mp, block, 1);
423  		if (i) {
424  			ASSERT(xfs_bmbt_disk_get_startoff(&last) +
425  			       xfs_bmbt_disk_get_blockcount(&last) <=
426  			       xfs_bmbt_disk_get_startoff(ep));
427  		}
428  		for (j = 1; j < num_recs; j++) {
429  			nextp = XFS_BMBT_REC_ADDR(mp, block, j + 1);
430  			ASSERT(xfs_bmbt_disk_get_startoff(ep) +
431  			       xfs_bmbt_disk_get_blockcount(ep) <=
432  			       xfs_bmbt_disk_get_startoff(nextp));
433  			ep = nextp;
434  		}
435  
436  		last = *ep;
437  		i += num_recs;
438  		if (bp_release) {
439  			bp_release = 0;
440  			xfs_trans_brelse(NULL, bp);
441  		}
442  		bno = nextbno;
443  		/*
444  		 * If we've reached the end, stop.
445  		 */
446  		if (bno == NULLFSBLOCK)
447  			break;
448  
449  		bp_release = 0;
450  		bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
451  		if (!bp) {
452  			bp_release = 1;
453  			error = xfs_btree_read_bufl(mp, NULL, bno, &bp,
454  						XFS_BMAP_BTREE_REF,
455  						&xfs_bmbt_buf_ops);
456  			if (error)
457  				goto error_norelse;
458  		}
459  		block = XFS_BUF_TO_BLOCK(bp);
460  	}
461  
462  	return;
463  
464  error0:
465  	xfs_warn(mp, "%s: at error0", __func__);
466  	if (bp_release)
467  		xfs_trans_brelse(NULL, bp);
468  error_norelse:
469  	xfs_warn(mp, "%s: BAD after btree leaves for %llu extents",
470  		__func__, i);
471  	xfs_err(mp, "%s: CORRUPTED BTREE OR SOMETHING", __func__);
472  	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
473  	return;
474  }
475  
476  /*
477   * Validate that the bmbt_irecs being returned from bmapi are valid
478   * given the caller's original parameters.  Specifically check the
479   * ranges of the returned irecs to ensure that they only extend beyond
480   * the given parameters if the XFS_BMAPI_ENTIRE flag was set.
481   */
482  STATIC void
483  xfs_bmap_validate_ret(
484  	xfs_fileoff_t		bno,
485  	xfs_filblks_t		len,
486  	uint32_t		flags,
487  	xfs_bmbt_irec_t		*mval,
488  	int			nmap,
489  	int			ret_nmap)
490  {
491  	int			i;		/* index to map values */
492  
493  	ASSERT(ret_nmap <= nmap);
494  
495  	for (i = 0; i < ret_nmap; i++) {
496  		ASSERT(mval[i].br_blockcount > 0);
497  		if (!(flags & XFS_BMAPI_ENTIRE)) {
498  			ASSERT(mval[i].br_startoff >= bno);
499  			ASSERT(mval[i].br_blockcount <= len);
500  			ASSERT(mval[i].br_startoff + mval[i].br_blockcount <=
501  			       bno + len);
502  		} else {
503  			ASSERT(mval[i].br_startoff < bno + len);
504  			ASSERT(mval[i].br_startoff + mval[i].br_blockcount >
505  			       bno);
506  		}
507  		ASSERT(i == 0 ||
508  		       mval[i - 1].br_startoff + mval[i - 1].br_blockcount ==
509  		       mval[i].br_startoff);
510  		ASSERT(mval[i].br_startblock != DELAYSTARTBLOCK &&
511  		       mval[i].br_startblock != HOLESTARTBLOCK);
512  		ASSERT(mval[i].br_state == XFS_EXT_NORM ||
513  		       mval[i].br_state == XFS_EXT_UNWRITTEN);
514  	}
515  }
516  
517  #else
518  #define xfs_bmap_check_leaf_extents(cur, ip, whichfork)		do { } while (0)
519  #define	xfs_bmap_validate_ret(bno,len,flags,mval,onmap,nmap)	do { } while (0)
520  #endif /* DEBUG */
521  
522  /*
523   * Inode fork format manipulation functions
524   */
525  
526  /*
527   * Convert the inode format to extent format if it currently is in btree format,
528   * but the extent list is small enough that it fits into the extent format.
529   *
530   * Since the extents are already in-core, all we have to do is give up the space
531   * for the btree root and pitch the leaf block.
532   */
533  STATIC int				/* error */
534  xfs_bmap_btree_to_extents(
535  	struct xfs_trans	*tp,	/* transaction pointer */
536  	struct xfs_inode	*ip,	/* incore inode pointer */
537  	struct xfs_btree_cur	*cur,	/* btree cursor */
538  	int			*logflagsp, /* inode logging flags */
539  	int			whichfork)  /* data or attr fork */
540  {
541  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
542  	struct xfs_mount	*mp = ip->i_mount;
543  	struct xfs_btree_block	*rblock = ifp->if_broot;
544  	struct xfs_btree_block	*cblock;/* child btree block */
545  	xfs_fsblock_t		cbno;	/* child block number */
546  	struct xfs_buf		*cbp;	/* child block's buffer */
547  	int			error;	/* error return value */
548  	__be64			*pp;	/* ptr to block address */
549  	struct xfs_owner_info	oinfo;
550  
551  	/* check if we actually need the extent format first: */
552  	if (!xfs_bmap_wants_extents(ip, whichfork))
553  		return 0;
554  
555  	ASSERT(cur);
556  	ASSERT(whichfork != XFS_COW_FORK);
557  	ASSERT(ifp->if_format == XFS_DINODE_FMT_BTREE);
558  	ASSERT(be16_to_cpu(rblock->bb_level) == 1);
559  	ASSERT(be16_to_cpu(rblock->bb_numrecs) == 1);
560  	ASSERT(xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0) == 1);
561  
562  	pp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, ifp->if_broot_bytes);
563  	cbno = be64_to_cpu(*pp);
564  #ifdef DEBUG
565  	if (XFS_IS_CORRUPT(cur->bc_mp, !xfs_btree_check_lptr(cur, cbno, 1)))
566  		return -EFSCORRUPTED;
567  #endif
568  	error = xfs_btree_read_bufl(mp, tp, cbno, &cbp, XFS_BMAP_BTREE_REF,
569  				&xfs_bmbt_buf_ops);
570  	if (error)
571  		return error;
572  	cblock = XFS_BUF_TO_BLOCK(cbp);
573  	if ((error = xfs_btree_check_block(cur, cblock, 0, cbp)))
574  		return error;
575  	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
576  	xfs_free_extent_later(cur->bc_tp, cbno, 1, &oinfo);
577  	ip->i_nblocks--;
578  	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
579  	xfs_trans_binval(tp, cbp);
580  	if (cur->bc_levels[0].bp == cbp)
581  		cur->bc_levels[0].bp = NULL;
582  	xfs_iroot_realloc(ip, -1, whichfork);
583  	ASSERT(ifp->if_broot == NULL);
584  	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
585  	*logflagsp |= XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
586  	return 0;
587  }
588  
589  /*
590   * Convert an extents-format file into a btree-format file.
591   * The new file will have a root block (in the inode) and a single child block.
592   */
593  STATIC int					/* error */
594  xfs_bmap_extents_to_btree(
595  	struct xfs_trans	*tp,		/* transaction pointer */
596  	struct xfs_inode	*ip,		/* incore inode pointer */
597  	struct xfs_btree_cur	**curp,		/* cursor returned to caller */
598  	int			wasdel,		/* converting a delayed alloc */
599  	int			*logflagsp,	/* inode logging flags */
600  	int			whichfork)	/* data or attr fork */
601  {
602  	struct xfs_btree_block	*ablock;	/* allocated (child) bt block */
603  	struct xfs_buf		*abp;		/* buffer for ablock */
604  	struct xfs_alloc_arg	args;		/* allocation arguments */
605  	struct xfs_bmbt_rec	*arp;		/* child record pointer */
606  	struct xfs_btree_block	*block;		/* btree root block */
607  	struct xfs_btree_cur	*cur;		/* bmap btree cursor */
608  	int			error;		/* error return value */
609  	struct xfs_ifork	*ifp;		/* inode fork pointer */
610  	struct xfs_bmbt_key	*kp;		/* root block key pointer */
611  	struct xfs_mount	*mp;		/* mount structure */
612  	xfs_bmbt_ptr_t		*pp;		/* root block address pointer */
613  	struct xfs_iext_cursor	icur;
614  	struct xfs_bmbt_irec	rec;
615  	xfs_extnum_t		cnt = 0;
616  
617  	mp = ip->i_mount;
618  	ASSERT(whichfork != XFS_COW_FORK);
619  	ifp = XFS_IFORK_PTR(ip, whichfork);
620  	ASSERT(ifp->if_format == XFS_DINODE_FMT_EXTENTS);
621  
622  	/*
623  	 * Make space in the inode incore. This needs to be undone if we fail
624  	 * to expand the root.
625  	 */
626  	xfs_iroot_realloc(ip, 1, whichfork);
627  
628  	/*
629  	 * Fill in the root.
630  	 */
631  	block = ifp->if_broot;
632  	xfs_btree_init_block_int(mp, block, XFS_BUF_DADDR_NULL,
633  				 XFS_BTNUM_BMAP, 1, 1, ip->i_ino,
634  				 XFS_BTREE_LONG_PTRS);
635  	/*
636  	 * Need a cursor.  Can't allocate until bb_level is filled in.
637  	 */
638  	cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
639  	cur->bc_ino.flags = wasdel ? XFS_BTCUR_BMBT_WASDEL : 0;
640  	/*
641  	 * Convert to a btree with two levels, one record in root.
642  	 */
643  	ifp->if_format = XFS_DINODE_FMT_BTREE;
644  	memset(&args, 0, sizeof(args));
645  	args.tp = tp;
646  	args.mp = mp;
647  	xfs_rmap_ino_bmbt_owner(&args.oinfo, ip->i_ino, whichfork);
648  	if (tp->t_firstblock == NULLFSBLOCK) {
649  		args.type = XFS_ALLOCTYPE_START_BNO;
650  		args.fsbno = XFS_INO_TO_FSB(mp, ip->i_ino);
651  	} else if (tp->t_flags & XFS_TRANS_LOWMODE) {
652  		args.type = XFS_ALLOCTYPE_START_BNO;
653  		args.fsbno = tp->t_firstblock;
654  	} else {
655  		args.type = XFS_ALLOCTYPE_NEAR_BNO;
656  		args.fsbno = tp->t_firstblock;
657  	}
658  	args.minlen = args.maxlen = args.prod = 1;
659  	args.wasdel = wasdel;
660  	*logflagsp = 0;
661  	error = xfs_alloc_vextent(&args);
662  	if (error)
663  		goto out_root_realloc;
664  
665  	if (WARN_ON_ONCE(args.fsbno == NULLFSBLOCK)) {
666  		error = -ENOSPC;
667  		goto out_root_realloc;
668  	}
669  
670  	/*
671  	 * Allocation can't fail, the space was reserved.
672  	 */
673  	ASSERT(tp->t_firstblock == NULLFSBLOCK ||
674  	       args.agno >= XFS_FSB_TO_AGNO(mp, tp->t_firstblock));
675  	tp->t_firstblock = args.fsbno;
676  	cur->bc_ino.allocated++;
677  	ip->i_nblocks++;
678  	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, 1L);
679  	error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
680  			XFS_FSB_TO_DADDR(mp, args.fsbno),
681  			mp->m_bsize, 0, &abp);
682  	if (error)
683  		goto out_unreserve_dquot;
684  
685  	/*
686  	 * Fill in the child block.
687  	 */
688  	abp->b_ops = &xfs_bmbt_buf_ops;
689  	ablock = XFS_BUF_TO_BLOCK(abp);
690  	xfs_btree_init_block_int(mp, ablock, xfs_buf_daddr(abp),
691  				XFS_BTNUM_BMAP, 0, 0, ip->i_ino,
692  				XFS_BTREE_LONG_PTRS);
693  
694  	for_each_xfs_iext(ifp, &icur, &rec) {
695  		if (isnullstartblock(rec.br_startblock))
696  			continue;
697  		arp = XFS_BMBT_REC_ADDR(mp, ablock, 1 + cnt);
698  		xfs_bmbt_disk_set_all(arp, &rec);
699  		cnt++;
700  	}
701  	ASSERT(cnt == ifp->if_nextents);
702  	xfs_btree_set_numrecs(ablock, cnt);
703  
704  	/*
705  	 * Fill in the root key and pointer.
706  	 */
707  	kp = XFS_BMBT_KEY_ADDR(mp, block, 1);
708  	arp = XFS_BMBT_REC_ADDR(mp, ablock, 1);
709  	kp->br_startoff = cpu_to_be64(xfs_bmbt_disk_get_startoff(arp));
710  	pp = XFS_BMBT_PTR_ADDR(mp, block, 1, xfs_bmbt_get_maxrecs(cur,
711  						be16_to_cpu(block->bb_level)));
712  	*pp = cpu_to_be64(args.fsbno);
713  
714  	/*
715  	 * Do all this logging at the end so that
716  	 * the root is at the right level.
717  	 */
718  	xfs_btree_log_block(cur, abp, XFS_BB_ALL_BITS);
719  	xfs_btree_log_recs(cur, abp, 1, be16_to_cpu(ablock->bb_numrecs));
720  	ASSERT(*curp == NULL);
721  	*curp = cur;
722  	*logflagsp = XFS_ILOG_CORE | xfs_ilog_fbroot(whichfork);
723  	return 0;
724  
725  out_unreserve_dquot:
726  	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
727  out_root_realloc:
728  	xfs_iroot_realloc(ip, -1, whichfork);
729  	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
730  	ASSERT(ifp->if_broot == NULL);
731  	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
732  
733  	return error;
734  }
735  
736  /*
737   * Convert a local file to an extents file.
738   * This code is out of bounds for data forks of regular files,
739   * since the file data needs to get logged so things will stay consistent.
740   * (The bmap-level manipulations are ok, though).
741   */
742  void
743  xfs_bmap_local_to_extents_empty(
744  	struct xfs_trans	*tp,
745  	struct xfs_inode	*ip,
746  	int			whichfork)
747  {
748  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
749  
750  	ASSERT(whichfork != XFS_COW_FORK);
751  	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
752  	ASSERT(ifp->if_bytes == 0);
753  	ASSERT(ifp->if_nextents == 0);
754  
755  	xfs_bmap_forkoff_reset(ip, whichfork);
756  	ifp->if_u1.if_root = NULL;
757  	ifp->if_height = 0;
758  	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
759  	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
760  }
761  
762  
763  STATIC int				/* error */
764  xfs_bmap_local_to_extents(
765  	xfs_trans_t	*tp,		/* transaction pointer */
766  	xfs_inode_t	*ip,		/* incore inode pointer */
767  	xfs_extlen_t	total,		/* total blocks needed by transaction */
768  	int		*logflagsp,	/* inode logging flags */
769  	int		whichfork,
770  	void		(*init_fn)(struct xfs_trans *tp,
771  				   struct xfs_buf *bp,
772  				   struct xfs_inode *ip,
773  				   struct xfs_ifork *ifp))
774  {
775  	int		error = 0;
776  	int		flags;		/* logging flags returned */
777  	struct xfs_ifork *ifp;		/* inode fork pointer */
778  	xfs_alloc_arg_t	args;		/* allocation arguments */
779  	struct xfs_buf	*bp;		/* buffer for extent block */
780  	struct xfs_bmbt_irec rec;
781  	struct xfs_iext_cursor icur;
782  
783  	/*
784  	 * We don't want to deal with the case of keeping inode data inline yet.
785  	 * So sending the data fork of a regular inode is invalid.
786  	 */
787  	ASSERT(!(S_ISREG(VFS_I(ip)->i_mode) && whichfork == XFS_DATA_FORK));
788  	ifp = XFS_IFORK_PTR(ip, whichfork);
789  	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
790  
791  	if (!ifp->if_bytes) {
792  		xfs_bmap_local_to_extents_empty(tp, ip, whichfork);
793  		flags = XFS_ILOG_CORE;
794  		goto done;
795  	}
796  
797  	flags = 0;
798  	error = 0;
799  	memset(&args, 0, sizeof(args));
800  	args.tp = tp;
801  	args.mp = ip->i_mount;
802  	xfs_rmap_ino_owner(&args.oinfo, ip->i_ino, whichfork, 0);
803  	/*
804  	 * Allocate a block.  We know we need only one, since the
805  	 * file currently fits in an inode.
806  	 */
807  	if (tp->t_firstblock == NULLFSBLOCK) {
808  		args.fsbno = XFS_INO_TO_FSB(args.mp, ip->i_ino);
809  		args.type = XFS_ALLOCTYPE_START_BNO;
810  	} else {
811  		args.fsbno = tp->t_firstblock;
812  		args.type = XFS_ALLOCTYPE_NEAR_BNO;
813  	}
814  	args.total = total;
815  	args.minlen = args.maxlen = args.prod = 1;
816  	error = xfs_alloc_vextent(&args);
817  	if (error)
818  		goto done;
819  
820  	/* Can't fail, the space was reserved. */
821  	ASSERT(args.fsbno != NULLFSBLOCK);
822  	ASSERT(args.len == 1);
823  	tp->t_firstblock = args.fsbno;
824  	error = xfs_trans_get_buf(tp, args.mp->m_ddev_targp,
825  			XFS_FSB_TO_DADDR(args.mp, args.fsbno),
826  			args.mp->m_bsize, 0, &bp);
827  	if (error)
828  		goto done;
829  
830  	/*
831  	 * Initialize the block, copy the data and log the remote buffer.
832  	 *
833  	 * The callout is responsible for logging because the remote format
834  	 * might differ from the local format and thus we don't know how much to
835  	 * log here. Note that init_fn must also set the buffer log item type
836  	 * correctly.
837  	 */
838  	init_fn(tp, bp, ip, ifp);
839  
840  	/* account for the change in fork size */
841  	xfs_idata_realloc(ip, -ifp->if_bytes, whichfork);
842  	xfs_bmap_local_to_extents_empty(tp, ip, whichfork);
843  	flags |= XFS_ILOG_CORE;
844  
845  	ifp->if_u1.if_root = NULL;
846  	ifp->if_height = 0;
847  
848  	rec.br_startoff = 0;
849  	rec.br_startblock = args.fsbno;
850  	rec.br_blockcount = 1;
851  	rec.br_state = XFS_EXT_NORM;
852  	xfs_iext_first(ifp, &icur);
853  	xfs_iext_insert(ip, &icur, &rec, 0);
854  
855  	ifp->if_nextents = 1;
856  	ip->i_nblocks = 1;
857  	xfs_trans_mod_dquot_byino(tp, ip,
858  		XFS_TRANS_DQ_BCOUNT, 1L);
859  	flags |= xfs_ilog_fext(whichfork);
860  
861  done:
862  	*logflagsp = flags;
863  	return error;
864  }
865  
866  /*
867   * Called from xfs_bmap_add_attrfork to handle btree format files.
868   */
869  STATIC int					/* error */
870  xfs_bmap_add_attrfork_btree(
871  	xfs_trans_t		*tp,		/* transaction pointer */
872  	xfs_inode_t		*ip,		/* incore inode pointer */
873  	int			*flags)		/* inode logging flags */
874  {
875  	struct xfs_btree_block	*block = ip->i_df.if_broot;
876  	struct xfs_btree_cur	*cur;		/* btree cursor */
877  	int			error;		/* error return value */
878  	xfs_mount_t		*mp;		/* file system mount struct */
879  	int			stat;		/* newroot status */
880  
881  	mp = ip->i_mount;
882  
883  	if (XFS_BMAP_BMDR_SPACE(block) <= XFS_IFORK_DSIZE(ip))
884  		*flags |= XFS_ILOG_DBROOT;
885  	else {
886  		cur = xfs_bmbt_init_cursor(mp, tp, ip, XFS_DATA_FORK);
887  		error = xfs_bmbt_lookup_first(cur, &stat);
888  		if (error)
889  			goto error0;
890  		/* must be at least one entry */
891  		if (XFS_IS_CORRUPT(mp, stat != 1)) {
892  			error = -EFSCORRUPTED;
893  			goto error0;
894  		}
895  		if ((error = xfs_btree_new_iroot(cur, flags, &stat)))
896  			goto error0;
897  		if (stat == 0) {
898  			xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
899  			return -ENOSPC;
900  		}
901  		cur->bc_ino.allocated = 0;
902  		xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
903  	}
904  	return 0;
905  error0:
906  	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
907  	return error;
908  }
909  
910  /*
911   * Called from xfs_bmap_add_attrfork to handle extents format files.
912   */
913  STATIC int					/* error */
914  xfs_bmap_add_attrfork_extents(
915  	struct xfs_trans	*tp,		/* transaction pointer */
916  	struct xfs_inode	*ip,		/* incore inode pointer */
917  	int			*flags)		/* inode logging flags */
918  {
919  	struct xfs_btree_cur	*cur;		/* bmap btree cursor */
920  	int			error;		/* error return value */
921  
922  	if (ip->i_df.if_nextents * sizeof(struct xfs_bmbt_rec) <=
923  	    XFS_IFORK_DSIZE(ip))
924  		return 0;
925  	cur = NULL;
926  	error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0, flags,
927  					  XFS_DATA_FORK);
928  	if (cur) {
929  		cur->bc_ino.allocated = 0;
930  		xfs_btree_del_cursor(cur, error);
931  	}
932  	return error;
933  }
934  
935  /*
936   * Called from xfs_bmap_add_attrfork to handle local format files. Each
937   * different data fork content type needs a different callout to do the
938   * conversion. Some are basic and only require special block initialisation
939   * callouts for the data formating, others (directories) are so specialised they
940   * handle everything themselves.
941   *
942   * XXX (dgc): investigate whether directory conversion can use the generic
943   * formatting callout. It should be possible - it's just a very complex
944   * formatter.
945   */
946  STATIC int					/* error */
947  xfs_bmap_add_attrfork_local(
948  	struct xfs_trans	*tp,		/* transaction pointer */
949  	struct xfs_inode	*ip,		/* incore inode pointer */
950  	int			*flags)		/* inode logging flags */
951  {
952  	struct xfs_da_args	dargs;		/* args for dir/attr code */
953  
954  	if (ip->i_df.if_bytes <= XFS_IFORK_DSIZE(ip))
955  		return 0;
956  
957  	if (S_ISDIR(VFS_I(ip)->i_mode)) {
958  		memset(&dargs, 0, sizeof(dargs));
959  		dargs.geo = ip->i_mount->m_dir_geo;
960  		dargs.dp = ip;
961  		dargs.total = dargs.geo->fsbcount;
962  		dargs.whichfork = XFS_DATA_FORK;
963  		dargs.trans = tp;
964  		return xfs_dir2_sf_to_block(&dargs);
965  	}
966  
967  	if (S_ISLNK(VFS_I(ip)->i_mode))
968  		return xfs_bmap_local_to_extents(tp, ip, 1, flags,
969  						 XFS_DATA_FORK,
970  						 xfs_symlink_local_to_remote);
971  
972  	/* should only be called for types that support local format data */
973  	ASSERT(0);
974  	return -EFSCORRUPTED;
975  }
976  
977  /*
978   * Set an inode attr fork offset based on the format of the data fork.
979   */
980  static int
981  xfs_bmap_set_attrforkoff(
982  	struct xfs_inode	*ip,
983  	int			size,
984  	int			*version)
985  {
986  	int			default_size = xfs_default_attroffset(ip) >> 3;
987  
988  	switch (ip->i_df.if_format) {
989  	case XFS_DINODE_FMT_DEV:
990  		ip->i_forkoff = default_size;
991  		break;
992  	case XFS_DINODE_FMT_LOCAL:
993  	case XFS_DINODE_FMT_EXTENTS:
994  	case XFS_DINODE_FMT_BTREE:
995  		ip->i_forkoff = xfs_attr_shortform_bytesfit(ip, size);
996  		if (!ip->i_forkoff)
997  			ip->i_forkoff = default_size;
998  		else if (xfs_has_attr2(ip->i_mount) && version)
999  			*version = 2;
1000  		break;
1001  	default:
1002  		ASSERT(0);
1003  		return -EINVAL;
1004  	}
1005  
1006  	return 0;
1007  }
1008  
1009  /*
1010   * Convert inode from non-attributed to attributed.
1011   * Must not be in a transaction, ip must not be locked.
1012   */
1013  int						/* error code */
1014  xfs_bmap_add_attrfork(
1015  	xfs_inode_t		*ip,		/* incore inode pointer */
1016  	int			size,		/* space new attribute needs */
1017  	int			rsvd)		/* xact may use reserved blks */
1018  {
1019  	xfs_mount_t		*mp;		/* mount structure */
1020  	xfs_trans_t		*tp;		/* transaction pointer */
1021  	int			blks;		/* space reservation */
1022  	int			version = 1;	/* superblock attr version */
1023  	int			logflags;	/* logging flags */
1024  	int			error;		/* error return value */
1025  
1026  	ASSERT(XFS_IFORK_Q(ip) == 0);
1027  
1028  	mp = ip->i_mount;
1029  	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1030  
1031  	blks = XFS_ADDAFORK_SPACE_RES(mp);
1032  
1033  	error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_addafork, blks, 0,
1034  			rsvd, &tp);
1035  	if (error)
1036  		return error;
1037  	if (XFS_IFORK_Q(ip))
1038  		goto trans_cancel;
1039  
1040  	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1041  	error = xfs_bmap_set_attrforkoff(ip, size, &version);
1042  	if (error)
1043  		goto trans_cancel;
1044  	ASSERT(ip->i_afp == NULL);
1045  
1046  	ip->i_afp = xfs_ifork_alloc(XFS_DINODE_FMT_EXTENTS, 0);
1047  	logflags = 0;
1048  	switch (ip->i_df.if_format) {
1049  	case XFS_DINODE_FMT_LOCAL:
1050  		error = xfs_bmap_add_attrfork_local(tp, ip, &logflags);
1051  		break;
1052  	case XFS_DINODE_FMT_EXTENTS:
1053  		error = xfs_bmap_add_attrfork_extents(tp, ip, &logflags);
1054  		break;
1055  	case XFS_DINODE_FMT_BTREE:
1056  		error = xfs_bmap_add_attrfork_btree(tp, ip, &logflags);
1057  		break;
1058  	default:
1059  		error = 0;
1060  		break;
1061  	}
1062  	if (logflags)
1063  		xfs_trans_log_inode(tp, ip, logflags);
1064  	if (error)
1065  		goto trans_cancel;
1066  	if (!xfs_has_attr(mp) ||
1067  	   (!xfs_has_attr2(mp) && version == 2)) {
1068  		bool log_sb = false;
1069  
1070  		spin_lock(&mp->m_sb_lock);
1071  		if (!xfs_has_attr(mp)) {
1072  			xfs_add_attr(mp);
1073  			log_sb = true;
1074  		}
1075  		if (!xfs_has_attr2(mp) && version == 2) {
1076  			xfs_add_attr2(mp);
1077  			log_sb = true;
1078  		}
1079  		spin_unlock(&mp->m_sb_lock);
1080  		if (log_sb)
1081  			xfs_log_sb(tp);
1082  	}
1083  
1084  	error = xfs_trans_commit(tp);
1085  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1086  	return error;
1087  
1088  trans_cancel:
1089  	xfs_trans_cancel(tp);
1090  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1091  	return error;
1092  }
1093  
1094  /*
1095   * Internal and external extent tree search functions.
1096   */
1097  
1098  struct xfs_iread_state {
1099  	struct xfs_iext_cursor	icur;
1100  	xfs_extnum_t		loaded;
1101  };
1102  
1103  /* Stuff every bmbt record from this block into the incore extent map. */
1104  static int
1105  xfs_iread_bmbt_block(
1106  	struct xfs_btree_cur	*cur,
1107  	int			level,
1108  	void			*priv)
1109  {
1110  	struct xfs_iread_state	*ir = priv;
1111  	struct xfs_mount	*mp = cur->bc_mp;
1112  	struct xfs_inode	*ip = cur->bc_ino.ip;
1113  	struct xfs_btree_block	*block;
1114  	struct xfs_buf		*bp;
1115  	struct xfs_bmbt_rec	*frp;
1116  	xfs_extnum_t		num_recs;
1117  	xfs_extnum_t		j;
1118  	int			whichfork = cur->bc_ino.whichfork;
1119  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
1120  
1121  	block = xfs_btree_get_block(cur, level, &bp);
1122  
1123  	/* Abort if we find more records than nextents. */
1124  	num_recs = xfs_btree_get_numrecs(block);
1125  	if (unlikely(ir->loaded + num_recs > ifp->if_nextents)) {
1126  		xfs_warn(ip->i_mount, "corrupt dinode %llu, (btree extents).",
1127  				(unsigned long long)ip->i_ino);
1128  		xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__, block,
1129  				sizeof(*block), __this_address);
1130  		return -EFSCORRUPTED;
1131  	}
1132  
1133  	/* Copy records into the incore cache. */
1134  	frp = XFS_BMBT_REC_ADDR(mp, block, 1);
1135  	for (j = 0; j < num_recs; j++, frp++, ir->loaded++) {
1136  		struct xfs_bmbt_irec	new;
1137  		xfs_failaddr_t		fa;
1138  
1139  		xfs_bmbt_disk_get_all(frp, &new);
1140  		fa = xfs_bmap_validate_extent(ip, whichfork, &new);
1141  		if (fa) {
1142  			xfs_inode_verifier_error(ip, -EFSCORRUPTED,
1143  					"xfs_iread_extents(2)", frp,
1144  					sizeof(*frp), fa);
1145  			return -EFSCORRUPTED;
1146  		}
1147  		xfs_iext_insert(ip, &ir->icur, &new,
1148  				xfs_bmap_fork_to_state(whichfork));
1149  		trace_xfs_read_extent(ip, &ir->icur,
1150  				xfs_bmap_fork_to_state(whichfork), _THIS_IP_);
1151  		xfs_iext_next(ifp, &ir->icur);
1152  	}
1153  
1154  	return 0;
1155  }
1156  
1157  /*
1158   * Read in extents from a btree-format inode.
1159   */
1160  int
1161  xfs_iread_extents(
1162  	struct xfs_trans	*tp,
1163  	struct xfs_inode	*ip,
1164  	int			whichfork)
1165  {
1166  	struct xfs_iread_state	ir;
1167  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
1168  	struct xfs_mount	*mp = ip->i_mount;
1169  	struct xfs_btree_cur	*cur;
1170  	int			error;
1171  
1172  	if (!xfs_need_iread_extents(ifp))
1173  		return 0;
1174  
1175  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1176  
1177  	ir.loaded = 0;
1178  	xfs_iext_first(ifp, &ir.icur);
1179  	cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
1180  	error = xfs_btree_visit_blocks(cur, xfs_iread_bmbt_block,
1181  			XFS_BTREE_VISIT_RECORDS, &ir);
1182  	xfs_btree_del_cursor(cur, error);
1183  	if (error)
1184  		goto out;
1185  
1186  	if (XFS_IS_CORRUPT(mp, ir.loaded != ifp->if_nextents)) {
1187  		error = -EFSCORRUPTED;
1188  		goto out;
1189  	}
1190  	ASSERT(ir.loaded == xfs_iext_count(ifp));
1191  	return 0;
1192  out:
1193  	xfs_iext_destroy(ifp);
1194  	return error;
1195  }
1196  
1197  /*
1198   * Returns the relative block number of the first unused block(s) in the given
1199   * fork with at least "len" logically contiguous blocks free.  This is the
1200   * lowest-address hole if the fork has holes, else the first block past the end
1201   * of fork.  Return 0 if the fork is currently local (in-inode).
1202   */
1203  int						/* error */
1204  xfs_bmap_first_unused(
1205  	struct xfs_trans	*tp,		/* transaction pointer */
1206  	struct xfs_inode	*ip,		/* incore inode */
1207  	xfs_extlen_t		len,		/* size of hole to find */
1208  	xfs_fileoff_t		*first_unused,	/* unused block */
1209  	int			whichfork)	/* data or attr fork */
1210  {
1211  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
1212  	struct xfs_bmbt_irec	got;
1213  	struct xfs_iext_cursor	icur;
1214  	xfs_fileoff_t		lastaddr = 0;
1215  	xfs_fileoff_t		lowest, max;
1216  	int			error;
1217  
1218  	if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
1219  		*first_unused = 0;
1220  		return 0;
1221  	}
1222  
1223  	ASSERT(xfs_ifork_has_extents(ifp));
1224  
1225  	error = xfs_iread_extents(tp, ip, whichfork);
1226  	if (error)
1227  		return error;
1228  
1229  	lowest = max = *first_unused;
1230  	for_each_xfs_iext(ifp, &icur, &got) {
1231  		/*
1232  		 * See if the hole before this extent will work.
1233  		 */
1234  		if (got.br_startoff >= lowest + len &&
1235  		    got.br_startoff - max >= len)
1236  			break;
1237  		lastaddr = got.br_startoff + got.br_blockcount;
1238  		max = XFS_FILEOFF_MAX(lastaddr, lowest);
1239  	}
1240  
1241  	*first_unused = max;
1242  	return 0;
1243  }
1244  
1245  /*
1246   * Returns the file-relative block number of the last block - 1 before
1247   * last_block (input value) in the file.
1248   * This is not based on i_size, it is based on the extent records.
1249   * Returns 0 for local files, as they do not have extent records.
1250   */
1251  int						/* error */
1252  xfs_bmap_last_before(
1253  	struct xfs_trans	*tp,		/* transaction pointer */
1254  	struct xfs_inode	*ip,		/* incore inode */
1255  	xfs_fileoff_t		*last_block,	/* last block */
1256  	int			whichfork)	/* data or attr fork */
1257  {
1258  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
1259  	struct xfs_bmbt_irec	got;
1260  	struct xfs_iext_cursor	icur;
1261  	int			error;
1262  
1263  	switch (ifp->if_format) {
1264  	case XFS_DINODE_FMT_LOCAL:
1265  		*last_block = 0;
1266  		return 0;
1267  	case XFS_DINODE_FMT_BTREE:
1268  	case XFS_DINODE_FMT_EXTENTS:
1269  		break;
1270  	default:
1271  		ASSERT(0);
1272  		return -EFSCORRUPTED;
1273  	}
1274  
1275  	error = xfs_iread_extents(tp, ip, whichfork);
1276  	if (error)
1277  		return error;
1278  
1279  	if (!xfs_iext_lookup_extent_before(ip, ifp, last_block, &icur, &got))
1280  		*last_block = 0;
1281  	return 0;
1282  }
1283  
1284  int
1285  xfs_bmap_last_extent(
1286  	struct xfs_trans	*tp,
1287  	struct xfs_inode	*ip,
1288  	int			whichfork,
1289  	struct xfs_bmbt_irec	*rec,
1290  	int			*is_empty)
1291  {
1292  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
1293  	struct xfs_iext_cursor	icur;
1294  	int			error;
1295  
1296  	error = xfs_iread_extents(tp, ip, whichfork);
1297  	if (error)
1298  		return error;
1299  
1300  	xfs_iext_last(ifp, &icur);
1301  	if (!xfs_iext_get_extent(ifp, &icur, rec))
1302  		*is_empty = 1;
1303  	else
1304  		*is_empty = 0;
1305  	return 0;
1306  }
1307  
1308  /*
1309   * Check the last inode extent to determine whether this allocation will result
1310   * in blocks being allocated at the end of the file. When we allocate new data
1311   * blocks at the end of the file which do not start at the previous data block,
1312   * we will try to align the new blocks at stripe unit boundaries.
1313   *
1314   * Returns 1 in bma->aeof if the file (fork) is empty as any new write will be
1315   * at, or past the EOF.
1316   */
1317  STATIC int
1318  xfs_bmap_isaeof(
1319  	struct xfs_bmalloca	*bma,
1320  	int			whichfork)
1321  {
1322  	struct xfs_bmbt_irec	rec;
1323  	int			is_empty;
1324  	int			error;
1325  
1326  	bma->aeof = false;
1327  	error = xfs_bmap_last_extent(NULL, bma->ip, whichfork, &rec,
1328  				     &is_empty);
1329  	if (error)
1330  		return error;
1331  
1332  	if (is_empty) {
1333  		bma->aeof = true;
1334  		return 0;
1335  	}
1336  
1337  	/*
1338  	 * Check if we are allocation or past the last extent, or at least into
1339  	 * the last delayed allocated extent.
1340  	 */
1341  	bma->aeof = bma->offset >= rec.br_startoff + rec.br_blockcount ||
1342  		(bma->offset >= rec.br_startoff &&
1343  		 isnullstartblock(rec.br_startblock));
1344  	return 0;
1345  }
1346  
1347  /*
1348   * Returns the file-relative block number of the first block past eof in
1349   * the file.  This is not based on i_size, it is based on the extent records.
1350   * Returns 0 for local files, as they do not have extent records.
1351   */
1352  int
1353  xfs_bmap_last_offset(
1354  	struct xfs_inode	*ip,
1355  	xfs_fileoff_t		*last_block,
1356  	int			whichfork)
1357  {
1358  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
1359  	struct xfs_bmbt_irec	rec;
1360  	int			is_empty;
1361  	int			error;
1362  
1363  	*last_block = 0;
1364  
1365  	if (ifp->if_format == XFS_DINODE_FMT_LOCAL)
1366  		return 0;
1367  
1368  	if (XFS_IS_CORRUPT(ip->i_mount, !xfs_ifork_has_extents(ifp)))
1369  		return -EFSCORRUPTED;
1370  
1371  	error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, &is_empty);
1372  	if (error || is_empty)
1373  		return error;
1374  
1375  	*last_block = rec.br_startoff + rec.br_blockcount;
1376  	return 0;
1377  }
1378  
1379  /*
1380   * Extent tree manipulation functions used during allocation.
1381   */
1382  
1383  /*
1384   * Convert a delayed allocation to a real allocation.
1385   */
1386  STATIC int				/* error */
1387  xfs_bmap_add_extent_delay_real(
1388  	struct xfs_bmalloca	*bma,
1389  	int			whichfork)
1390  {
1391  	struct xfs_mount	*mp = bma->ip->i_mount;
1392  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(bma->ip, whichfork);
1393  	struct xfs_bmbt_irec	*new = &bma->got;
1394  	int			error;	/* error return value */
1395  	int			i;	/* temp state */
1396  	xfs_fileoff_t		new_endoff;	/* end offset of new entry */
1397  	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
1398  					/* left is 0, right is 1, prev is 2 */
1399  	int			rval=0;	/* return value (logging flags) */
1400  	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
1401  	xfs_filblks_t		da_new; /* new count del alloc blocks used */
1402  	xfs_filblks_t		da_old; /* old count del alloc blocks used */
1403  	xfs_filblks_t		temp=0;	/* value for da_new calculations */
1404  	int			tmp_rval;	/* partial logging flags */
1405  	struct xfs_bmbt_irec	old;
1406  
1407  	ASSERT(whichfork != XFS_ATTR_FORK);
1408  	ASSERT(!isnullstartblock(new->br_startblock));
1409  	ASSERT(!bma->cur ||
1410  	       (bma->cur->bc_ino.flags & XFS_BTCUR_BMBT_WASDEL));
1411  
1412  	XFS_STATS_INC(mp, xs_add_exlist);
1413  
1414  #define	LEFT		r[0]
1415  #define	RIGHT		r[1]
1416  #define	PREV		r[2]
1417  
1418  	/*
1419  	 * Set up a bunch of variables to make the tests simpler.
1420  	 */
1421  	xfs_iext_get_extent(ifp, &bma->icur, &PREV);
1422  	new_endoff = new->br_startoff + new->br_blockcount;
1423  	ASSERT(isnullstartblock(PREV.br_startblock));
1424  	ASSERT(PREV.br_startoff <= new->br_startoff);
1425  	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
1426  
1427  	da_old = startblockval(PREV.br_startblock);
1428  	da_new = 0;
1429  
1430  	/*
1431  	 * Set flags determining what part of the previous delayed allocation
1432  	 * extent is being replaced by a real allocation.
1433  	 */
1434  	if (PREV.br_startoff == new->br_startoff)
1435  		state |= BMAP_LEFT_FILLING;
1436  	if (PREV.br_startoff + PREV.br_blockcount == new_endoff)
1437  		state |= BMAP_RIGHT_FILLING;
1438  
1439  	/*
1440  	 * Check and set flags if this segment has a left neighbor.
1441  	 * Don't set contiguous if the combined extent would be too large.
1442  	 */
1443  	if (xfs_iext_peek_prev_extent(ifp, &bma->icur, &LEFT)) {
1444  		state |= BMAP_LEFT_VALID;
1445  		if (isnullstartblock(LEFT.br_startblock))
1446  			state |= BMAP_LEFT_DELAY;
1447  	}
1448  
1449  	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
1450  	    LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
1451  	    LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
1452  	    LEFT.br_state == new->br_state &&
1453  	    LEFT.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
1454  		state |= BMAP_LEFT_CONTIG;
1455  
1456  	/*
1457  	 * Check and set flags if this segment has a right neighbor.
1458  	 * Don't set contiguous if the combined extent would be too large.
1459  	 * Also check for all-three-contiguous being too large.
1460  	 */
1461  	if (xfs_iext_peek_next_extent(ifp, &bma->icur, &RIGHT)) {
1462  		state |= BMAP_RIGHT_VALID;
1463  		if (isnullstartblock(RIGHT.br_startblock))
1464  			state |= BMAP_RIGHT_DELAY;
1465  	}
1466  
1467  	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
1468  	    new_endoff == RIGHT.br_startoff &&
1469  	    new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
1470  	    new->br_state == RIGHT.br_state &&
1471  	    new->br_blockcount + RIGHT.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
1472  	    ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
1473  		       BMAP_RIGHT_FILLING)) !=
1474  		      (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
1475  		       BMAP_RIGHT_FILLING) ||
1476  	     LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
1477  			<= XFS_MAX_BMBT_EXTLEN))
1478  		state |= BMAP_RIGHT_CONTIG;
1479  
1480  	error = 0;
1481  	/*
1482  	 * Switch out based on the FILLING and CONTIG state bits.
1483  	 */
1484  	switch (state & (BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
1485  			 BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG)) {
1486  	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
1487  	     BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1488  		/*
1489  		 * Filling in all of a previously delayed allocation extent.
1490  		 * The left and right neighbors are both contiguous with new.
1491  		 */
1492  		LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
1493  
1494  		xfs_iext_remove(bma->ip, &bma->icur, state);
1495  		xfs_iext_remove(bma->ip, &bma->icur, state);
1496  		xfs_iext_prev(ifp, &bma->icur);
1497  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1498  		ifp->if_nextents--;
1499  
1500  		if (bma->cur == NULL)
1501  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1502  		else {
1503  			rval = XFS_ILOG_CORE;
1504  			error = xfs_bmbt_lookup_eq(bma->cur, &RIGHT, &i);
1505  			if (error)
1506  				goto done;
1507  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1508  				error = -EFSCORRUPTED;
1509  				goto done;
1510  			}
1511  			error = xfs_btree_delete(bma->cur, &i);
1512  			if (error)
1513  				goto done;
1514  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1515  				error = -EFSCORRUPTED;
1516  				goto done;
1517  			}
1518  			error = xfs_btree_decrement(bma->cur, 0, &i);
1519  			if (error)
1520  				goto done;
1521  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1522  				error = -EFSCORRUPTED;
1523  				goto done;
1524  			}
1525  			error = xfs_bmbt_update(bma->cur, &LEFT);
1526  			if (error)
1527  				goto done;
1528  		}
1529  		break;
1530  
1531  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
1532  		/*
1533  		 * Filling in all of a previously delayed allocation extent.
1534  		 * The left neighbor is contiguous, the right is not.
1535  		 */
1536  		old = LEFT;
1537  		LEFT.br_blockcount += PREV.br_blockcount;
1538  
1539  		xfs_iext_remove(bma->ip, &bma->icur, state);
1540  		xfs_iext_prev(ifp, &bma->icur);
1541  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1542  
1543  		if (bma->cur == NULL)
1544  			rval = XFS_ILOG_DEXT;
1545  		else {
1546  			rval = 0;
1547  			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1548  			if (error)
1549  				goto done;
1550  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1551  				error = -EFSCORRUPTED;
1552  				goto done;
1553  			}
1554  			error = xfs_bmbt_update(bma->cur, &LEFT);
1555  			if (error)
1556  				goto done;
1557  		}
1558  		break;
1559  
1560  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1561  		/*
1562  		 * Filling in all of a previously delayed allocation extent.
1563  		 * The right neighbor is contiguous, the left is not. Take care
1564  		 * with delay -> unwritten extent allocation here because the
1565  		 * delalloc record we are overwriting is always written.
1566  		 */
1567  		PREV.br_startblock = new->br_startblock;
1568  		PREV.br_blockcount += RIGHT.br_blockcount;
1569  		PREV.br_state = new->br_state;
1570  
1571  		xfs_iext_next(ifp, &bma->icur);
1572  		xfs_iext_remove(bma->ip, &bma->icur, state);
1573  		xfs_iext_prev(ifp, &bma->icur);
1574  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1575  
1576  		if (bma->cur == NULL)
1577  			rval = XFS_ILOG_DEXT;
1578  		else {
1579  			rval = 0;
1580  			error = xfs_bmbt_lookup_eq(bma->cur, &RIGHT, &i);
1581  			if (error)
1582  				goto done;
1583  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1584  				error = -EFSCORRUPTED;
1585  				goto done;
1586  			}
1587  			error = xfs_bmbt_update(bma->cur, &PREV);
1588  			if (error)
1589  				goto done;
1590  		}
1591  		break;
1592  
1593  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
1594  		/*
1595  		 * Filling in all of a previously delayed allocation extent.
1596  		 * Neither the left nor right neighbors are contiguous with
1597  		 * the new one.
1598  		 */
1599  		PREV.br_startblock = new->br_startblock;
1600  		PREV.br_state = new->br_state;
1601  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1602  		ifp->if_nextents++;
1603  
1604  		if (bma->cur == NULL)
1605  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1606  		else {
1607  			rval = XFS_ILOG_CORE;
1608  			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1609  			if (error)
1610  				goto done;
1611  			if (XFS_IS_CORRUPT(mp, i != 0)) {
1612  				error = -EFSCORRUPTED;
1613  				goto done;
1614  			}
1615  			error = xfs_btree_insert(bma->cur, &i);
1616  			if (error)
1617  				goto done;
1618  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1619  				error = -EFSCORRUPTED;
1620  				goto done;
1621  			}
1622  		}
1623  		break;
1624  
1625  	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG:
1626  		/*
1627  		 * Filling in the first part of a previous delayed allocation.
1628  		 * The left neighbor is contiguous.
1629  		 */
1630  		old = LEFT;
1631  		temp = PREV.br_blockcount - new->br_blockcount;
1632  		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1633  				startblockval(PREV.br_startblock));
1634  
1635  		LEFT.br_blockcount += new->br_blockcount;
1636  
1637  		PREV.br_blockcount = temp;
1638  		PREV.br_startoff += new->br_blockcount;
1639  		PREV.br_startblock = nullstartblock(da_new);
1640  
1641  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1642  		xfs_iext_prev(ifp, &bma->icur);
1643  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1644  
1645  		if (bma->cur == NULL)
1646  			rval = XFS_ILOG_DEXT;
1647  		else {
1648  			rval = 0;
1649  			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1650  			if (error)
1651  				goto done;
1652  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1653  				error = -EFSCORRUPTED;
1654  				goto done;
1655  			}
1656  			error = xfs_bmbt_update(bma->cur, &LEFT);
1657  			if (error)
1658  				goto done;
1659  		}
1660  		break;
1661  
1662  	case BMAP_LEFT_FILLING:
1663  		/*
1664  		 * Filling in the first part of a previous delayed allocation.
1665  		 * The left neighbor is not contiguous.
1666  		 */
1667  		xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
1668  		ifp->if_nextents++;
1669  
1670  		if (bma->cur == NULL)
1671  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1672  		else {
1673  			rval = XFS_ILOG_CORE;
1674  			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1675  			if (error)
1676  				goto done;
1677  			if (XFS_IS_CORRUPT(mp, i != 0)) {
1678  				error = -EFSCORRUPTED;
1679  				goto done;
1680  			}
1681  			error = xfs_btree_insert(bma->cur, &i);
1682  			if (error)
1683  				goto done;
1684  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1685  				error = -EFSCORRUPTED;
1686  				goto done;
1687  			}
1688  		}
1689  
1690  		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1691  			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1692  					&bma->cur, 1, &tmp_rval, whichfork);
1693  			rval |= tmp_rval;
1694  			if (error)
1695  				goto done;
1696  		}
1697  
1698  		temp = PREV.br_blockcount - new->br_blockcount;
1699  		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1700  			startblockval(PREV.br_startblock) -
1701  			(bma->cur ? bma->cur->bc_ino.allocated : 0));
1702  
1703  		PREV.br_startoff = new_endoff;
1704  		PREV.br_blockcount = temp;
1705  		PREV.br_startblock = nullstartblock(da_new);
1706  		xfs_iext_next(ifp, &bma->icur);
1707  		xfs_iext_insert(bma->ip, &bma->icur, &PREV, state);
1708  		xfs_iext_prev(ifp, &bma->icur);
1709  		break;
1710  
1711  	case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1712  		/*
1713  		 * Filling in the last part of a previous delayed allocation.
1714  		 * The right neighbor is contiguous with the new allocation.
1715  		 */
1716  		old = RIGHT;
1717  		RIGHT.br_startoff = new->br_startoff;
1718  		RIGHT.br_startblock = new->br_startblock;
1719  		RIGHT.br_blockcount += new->br_blockcount;
1720  
1721  		if (bma->cur == NULL)
1722  			rval = XFS_ILOG_DEXT;
1723  		else {
1724  			rval = 0;
1725  			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1726  			if (error)
1727  				goto done;
1728  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1729  				error = -EFSCORRUPTED;
1730  				goto done;
1731  			}
1732  			error = xfs_bmbt_update(bma->cur, &RIGHT);
1733  			if (error)
1734  				goto done;
1735  		}
1736  
1737  		temp = PREV.br_blockcount - new->br_blockcount;
1738  		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1739  			startblockval(PREV.br_startblock));
1740  
1741  		PREV.br_blockcount = temp;
1742  		PREV.br_startblock = nullstartblock(da_new);
1743  
1744  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1745  		xfs_iext_next(ifp, &bma->icur);
1746  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &RIGHT);
1747  		break;
1748  
1749  	case BMAP_RIGHT_FILLING:
1750  		/*
1751  		 * Filling in the last part of a previous delayed allocation.
1752  		 * The right neighbor is not contiguous.
1753  		 */
1754  		xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
1755  		ifp->if_nextents++;
1756  
1757  		if (bma->cur == NULL)
1758  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1759  		else {
1760  			rval = XFS_ILOG_CORE;
1761  			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1762  			if (error)
1763  				goto done;
1764  			if (XFS_IS_CORRUPT(mp, i != 0)) {
1765  				error = -EFSCORRUPTED;
1766  				goto done;
1767  			}
1768  			error = xfs_btree_insert(bma->cur, &i);
1769  			if (error)
1770  				goto done;
1771  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1772  				error = -EFSCORRUPTED;
1773  				goto done;
1774  			}
1775  		}
1776  
1777  		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1778  			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1779  				&bma->cur, 1, &tmp_rval, whichfork);
1780  			rval |= tmp_rval;
1781  			if (error)
1782  				goto done;
1783  		}
1784  
1785  		temp = PREV.br_blockcount - new->br_blockcount;
1786  		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1787  			startblockval(PREV.br_startblock) -
1788  			(bma->cur ? bma->cur->bc_ino.allocated : 0));
1789  
1790  		PREV.br_startblock = nullstartblock(da_new);
1791  		PREV.br_blockcount = temp;
1792  		xfs_iext_insert(bma->ip, &bma->icur, &PREV, state);
1793  		xfs_iext_next(ifp, &bma->icur);
1794  		break;
1795  
1796  	case 0:
1797  		/*
1798  		 * Filling in the middle part of a previous delayed allocation.
1799  		 * Contiguity is impossible here.
1800  		 * This case is avoided almost all the time.
1801  		 *
1802  		 * We start with a delayed allocation:
1803  		 *
1804  		 * +ddddddddddddddddddddddddddddddddddddddddddddddddddddddd+
1805  		 *  PREV @ idx
1806  		 *
1807  	         * and we are allocating:
1808  		 *                     +rrrrrrrrrrrrrrrrr+
1809  		 *			      new
1810  		 *
1811  		 * and we set it up for insertion as:
1812  		 * +ddddddddddddddddddd+rrrrrrrrrrrrrrrrr+ddddddddddddddddd+
1813  		 *                            new
1814  		 *  PREV @ idx          LEFT              RIGHT
1815  		 *                      inserted at idx + 1
1816  		 */
1817  		old = PREV;
1818  
1819  		/* LEFT is the new middle */
1820  		LEFT = *new;
1821  
1822  		/* RIGHT is the new right */
1823  		RIGHT.br_state = PREV.br_state;
1824  		RIGHT.br_startoff = new_endoff;
1825  		RIGHT.br_blockcount =
1826  			PREV.br_startoff + PREV.br_blockcount - new_endoff;
1827  		RIGHT.br_startblock =
1828  			nullstartblock(xfs_bmap_worst_indlen(bma->ip,
1829  					RIGHT.br_blockcount));
1830  
1831  		/* truncate PREV */
1832  		PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
1833  		PREV.br_startblock =
1834  			nullstartblock(xfs_bmap_worst_indlen(bma->ip,
1835  					PREV.br_blockcount));
1836  		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1837  
1838  		xfs_iext_next(ifp, &bma->icur);
1839  		xfs_iext_insert(bma->ip, &bma->icur, &RIGHT, state);
1840  		xfs_iext_insert(bma->ip, &bma->icur, &LEFT, state);
1841  		ifp->if_nextents++;
1842  
1843  		if (bma->cur == NULL)
1844  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1845  		else {
1846  			rval = XFS_ILOG_CORE;
1847  			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1848  			if (error)
1849  				goto done;
1850  			if (XFS_IS_CORRUPT(mp, i != 0)) {
1851  				error = -EFSCORRUPTED;
1852  				goto done;
1853  			}
1854  			error = xfs_btree_insert(bma->cur, &i);
1855  			if (error)
1856  				goto done;
1857  			if (XFS_IS_CORRUPT(mp, i != 1)) {
1858  				error = -EFSCORRUPTED;
1859  				goto done;
1860  			}
1861  		}
1862  
1863  		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1864  			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1865  					&bma->cur, 1, &tmp_rval, whichfork);
1866  			rval |= tmp_rval;
1867  			if (error)
1868  				goto done;
1869  		}
1870  
1871  		da_new = startblockval(PREV.br_startblock) +
1872  			 startblockval(RIGHT.br_startblock);
1873  		break;
1874  
1875  	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1876  	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1877  	case BMAP_LEFT_FILLING | BMAP_RIGHT_CONTIG:
1878  	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
1879  	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1880  	case BMAP_LEFT_CONTIG:
1881  	case BMAP_RIGHT_CONTIG:
1882  		/*
1883  		 * These cases are all impossible.
1884  		 */
1885  		ASSERT(0);
1886  	}
1887  
1888  	/* add reverse mapping unless caller opted out */
1889  	if (!(bma->flags & XFS_BMAPI_NORMAP))
1890  		xfs_rmap_map_extent(bma->tp, bma->ip, whichfork, new);
1891  
1892  	/* convert to a btree if necessary */
1893  	if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1894  		int	tmp_logflags;	/* partial log flag return val */
1895  
1896  		ASSERT(bma->cur == NULL);
1897  		error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1898  				&bma->cur, da_old > 0, &tmp_logflags,
1899  				whichfork);
1900  		bma->logflags |= tmp_logflags;
1901  		if (error)
1902  			goto done;
1903  	}
1904  
1905  	if (da_new != da_old)
1906  		xfs_mod_delalloc(mp, (int64_t)da_new - da_old);
1907  
1908  	if (bma->cur) {
1909  		da_new += bma->cur->bc_ino.allocated;
1910  		bma->cur->bc_ino.allocated = 0;
1911  	}
1912  
1913  	/* adjust for changes in reserved delayed indirect blocks */
1914  	if (da_new != da_old) {
1915  		ASSERT(state == 0 || da_new < da_old);
1916  		error = xfs_mod_fdblocks(mp, (int64_t)(da_old - da_new),
1917  				false);
1918  	}
1919  
1920  	xfs_bmap_check_leaf_extents(bma->cur, bma->ip, whichfork);
1921  done:
1922  	if (whichfork != XFS_COW_FORK)
1923  		bma->logflags |= rval;
1924  	return error;
1925  #undef	LEFT
1926  #undef	RIGHT
1927  #undef	PREV
1928  }
1929  
1930  /*
1931   * Convert an unwritten allocation to a real allocation or vice versa.
1932   */
1933  int					/* error */
1934  xfs_bmap_add_extent_unwritten_real(
1935  	struct xfs_trans	*tp,
1936  	xfs_inode_t		*ip,	/* incore inode pointer */
1937  	int			whichfork,
1938  	struct xfs_iext_cursor	*icur,
1939  	struct xfs_btree_cur	**curp,	/* if *curp is null, not a btree */
1940  	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
1941  	int			*logflagsp) /* inode logging flags */
1942  {
1943  	struct xfs_btree_cur	*cur;	/* btree cursor */
1944  	int			error;	/* error return value */
1945  	int			i;	/* temp state */
1946  	struct xfs_ifork	*ifp;	/* inode fork pointer */
1947  	xfs_fileoff_t		new_endoff;	/* end offset of new entry */
1948  	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
1949  					/* left is 0, right is 1, prev is 2 */
1950  	int			rval=0;	/* return value (logging flags) */
1951  	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
1952  	struct xfs_mount	*mp = ip->i_mount;
1953  	struct xfs_bmbt_irec	old;
1954  
1955  	*logflagsp = 0;
1956  
1957  	cur = *curp;
1958  	ifp = XFS_IFORK_PTR(ip, whichfork);
1959  
1960  	ASSERT(!isnullstartblock(new->br_startblock));
1961  
1962  	XFS_STATS_INC(mp, xs_add_exlist);
1963  
1964  #define	LEFT		r[0]
1965  #define	RIGHT		r[1]
1966  #define	PREV		r[2]
1967  
1968  	/*
1969  	 * Set up a bunch of variables to make the tests simpler.
1970  	 */
1971  	error = 0;
1972  	xfs_iext_get_extent(ifp, icur, &PREV);
1973  	ASSERT(new->br_state != PREV.br_state);
1974  	new_endoff = new->br_startoff + new->br_blockcount;
1975  	ASSERT(PREV.br_startoff <= new->br_startoff);
1976  	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
1977  
1978  	/*
1979  	 * Set flags determining what part of the previous oldext allocation
1980  	 * extent is being replaced by a newext allocation.
1981  	 */
1982  	if (PREV.br_startoff == new->br_startoff)
1983  		state |= BMAP_LEFT_FILLING;
1984  	if (PREV.br_startoff + PREV.br_blockcount == new_endoff)
1985  		state |= BMAP_RIGHT_FILLING;
1986  
1987  	/*
1988  	 * Check and set flags if this segment has a left neighbor.
1989  	 * Don't set contiguous if the combined extent would be too large.
1990  	 */
1991  	if (xfs_iext_peek_prev_extent(ifp, icur, &LEFT)) {
1992  		state |= BMAP_LEFT_VALID;
1993  		if (isnullstartblock(LEFT.br_startblock))
1994  			state |= BMAP_LEFT_DELAY;
1995  	}
1996  
1997  	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
1998  	    LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
1999  	    LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
2000  	    LEFT.br_state == new->br_state &&
2001  	    LEFT.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2002  		state |= BMAP_LEFT_CONTIG;
2003  
2004  	/*
2005  	 * Check and set flags if this segment has a right neighbor.
2006  	 * Don't set contiguous if the combined extent would be too large.
2007  	 * Also check for all-three-contiguous being too large.
2008  	 */
2009  	if (xfs_iext_peek_next_extent(ifp, icur, &RIGHT)) {
2010  		state |= BMAP_RIGHT_VALID;
2011  		if (isnullstartblock(RIGHT.br_startblock))
2012  			state |= BMAP_RIGHT_DELAY;
2013  	}
2014  
2015  	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
2016  	    new_endoff == RIGHT.br_startoff &&
2017  	    new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
2018  	    new->br_state == RIGHT.br_state &&
2019  	    new->br_blockcount + RIGHT.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2020  	    ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
2021  		       BMAP_RIGHT_FILLING)) !=
2022  		      (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
2023  		       BMAP_RIGHT_FILLING) ||
2024  	     LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
2025  			<= XFS_MAX_BMBT_EXTLEN))
2026  		state |= BMAP_RIGHT_CONTIG;
2027  
2028  	/*
2029  	 * Switch out based on the FILLING and CONTIG state bits.
2030  	 */
2031  	switch (state & (BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
2032  			 BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG)) {
2033  	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
2034  	     BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2035  		/*
2036  		 * Setting all of a previous oldext extent to newext.
2037  		 * The left and right neighbors are both contiguous with new.
2038  		 */
2039  		LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
2040  
2041  		xfs_iext_remove(ip, icur, state);
2042  		xfs_iext_remove(ip, icur, state);
2043  		xfs_iext_prev(ifp, icur);
2044  		xfs_iext_update_extent(ip, state, icur, &LEFT);
2045  		ifp->if_nextents -= 2;
2046  		if (cur == NULL)
2047  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2048  		else {
2049  			rval = XFS_ILOG_CORE;
2050  			error = xfs_bmbt_lookup_eq(cur, &RIGHT, &i);
2051  			if (error)
2052  				goto done;
2053  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2054  				error = -EFSCORRUPTED;
2055  				goto done;
2056  			}
2057  			if ((error = xfs_btree_delete(cur, &i)))
2058  				goto done;
2059  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2060  				error = -EFSCORRUPTED;
2061  				goto done;
2062  			}
2063  			if ((error = xfs_btree_decrement(cur, 0, &i)))
2064  				goto done;
2065  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2066  				error = -EFSCORRUPTED;
2067  				goto done;
2068  			}
2069  			if ((error = xfs_btree_delete(cur, &i)))
2070  				goto done;
2071  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2072  				error = -EFSCORRUPTED;
2073  				goto done;
2074  			}
2075  			if ((error = xfs_btree_decrement(cur, 0, &i)))
2076  				goto done;
2077  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2078  				error = -EFSCORRUPTED;
2079  				goto done;
2080  			}
2081  			error = xfs_bmbt_update(cur, &LEFT);
2082  			if (error)
2083  				goto done;
2084  		}
2085  		break;
2086  
2087  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
2088  		/*
2089  		 * Setting all of a previous oldext extent to newext.
2090  		 * The left neighbor is contiguous, the right is not.
2091  		 */
2092  		LEFT.br_blockcount += PREV.br_blockcount;
2093  
2094  		xfs_iext_remove(ip, icur, state);
2095  		xfs_iext_prev(ifp, icur);
2096  		xfs_iext_update_extent(ip, state, icur, &LEFT);
2097  		ifp->if_nextents--;
2098  		if (cur == NULL)
2099  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2100  		else {
2101  			rval = XFS_ILOG_CORE;
2102  			error = xfs_bmbt_lookup_eq(cur, &PREV, &i);
2103  			if (error)
2104  				goto done;
2105  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2106  				error = -EFSCORRUPTED;
2107  				goto done;
2108  			}
2109  			if ((error = xfs_btree_delete(cur, &i)))
2110  				goto done;
2111  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2112  				error = -EFSCORRUPTED;
2113  				goto done;
2114  			}
2115  			if ((error = xfs_btree_decrement(cur, 0, &i)))
2116  				goto done;
2117  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2118  				error = -EFSCORRUPTED;
2119  				goto done;
2120  			}
2121  			error = xfs_bmbt_update(cur, &LEFT);
2122  			if (error)
2123  				goto done;
2124  		}
2125  		break;
2126  
2127  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2128  		/*
2129  		 * Setting all of a previous oldext extent to newext.
2130  		 * The right neighbor is contiguous, the left is not.
2131  		 */
2132  		PREV.br_blockcount += RIGHT.br_blockcount;
2133  		PREV.br_state = new->br_state;
2134  
2135  		xfs_iext_next(ifp, icur);
2136  		xfs_iext_remove(ip, icur, state);
2137  		xfs_iext_prev(ifp, icur);
2138  		xfs_iext_update_extent(ip, state, icur, &PREV);
2139  		ifp->if_nextents--;
2140  
2141  		if (cur == NULL)
2142  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2143  		else {
2144  			rval = XFS_ILOG_CORE;
2145  			error = xfs_bmbt_lookup_eq(cur, &RIGHT, &i);
2146  			if (error)
2147  				goto done;
2148  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2149  				error = -EFSCORRUPTED;
2150  				goto done;
2151  			}
2152  			if ((error = xfs_btree_delete(cur, &i)))
2153  				goto done;
2154  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2155  				error = -EFSCORRUPTED;
2156  				goto done;
2157  			}
2158  			if ((error = xfs_btree_decrement(cur, 0, &i)))
2159  				goto done;
2160  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2161  				error = -EFSCORRUPTED;
2162  				goto done;
2163  			}
2164  			error = xfs_bmbt_update(cur, &PREV);
2165  			if (error)
2166  				goto done;
2167  		}
2168  		break;
2169  
2170  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
2171  		/*
2172  		 * Setting all of a previous oldext extent to newext.
2173  		 * Neither the left nor right neighbors are contiguous with
2174  		 * the new one.
2175  		 */
2176  		PREV.br_state = new->br_state;
2177  		xfs_iext_update_extent(ip, state, icur, &PREV);
2178  
2179  		if (cur == NULL)
2180  			rval = XFS_ILOG_DEXT;
2181  		else {
2182  			rval = 0;
2183  			error = xfs_bmbt_lookup_eq(cur, new, &i);
2184  			if (error)
2185  				goto done;
2186  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2187  				error = -EFSCORRUPTED;
2188  				goto done;
2189  			}
2190  			error = xfs_bmbt_update(cur, &PREV);
2191  			if (error)
2192  				goto done;
2193  		}
2194  		break;
2195  
2196  	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG:
2197  		/*
2198  		 * Setting the first part of a previous oldext extent to newext.
2199  		 * The left neighbor is contiguous.
2200  		 */
2201  		LEFT.br_blockcount += new->br_blockcount;
2202  
2203  		old = PREV;
2204  		PREV.br_startoff += new->br_blockcount;
2205  		PREV.br_startblock += new->br_blockcount;
2206  		PREV.br_blockcount -= new->br_blockcount;
2207  
2208  		xfs_iext_update_extent(ip, state, icur, &PREV);
2209  		xfs_iext_prev(ifp, icur);
2210  		xfs_iext_update_extent(ip, state, icur, &LEFT);
2211  
2212  		if (cur == NULL)
2213  			rval = XFS_ILOG_DEXT;
2214  		else {
2215  			rval = 0;
2216  			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2217  			if (error)
2218  				goto done;
2219  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2220  				error = -EFSCORRUPTED;
2221  				goto done;
2222  			}
2223  			error = xfs_bmbt_update(cur, &PREV);
2224  			if (error)
2225  				goto done;
2226  			error = xfs_btree_decrement(cur, 0, &i);
2227  			if (error)
2228  				goto done;
2229  			error = xfs_bmbt_update(cur, &LEFT);
2230  			if (error)
2231  				goto done;
2232  		}
2233  		break;
2234  
2235  	case BMAP_LEFT_FILLING:
2236  		/*
2237  		 * Setting the first part of a previous oldext extent to newext.
2238  		 * The left neighbor is not contiguous.
2239  		 */
2240  		old = PREV;
2241  		PREV.br_startoff += new->br_blockcount;
2242  		PREV.br_startblock += new->br_blockcount;
2243  		PREV.br_blockcount -= new->br_blockcount;
2244  
2245  		xfs_iext_update_extent(ip, state, icur, &PREV);
2246  		xfs_iext_insert(ip, icur, new, state);
2247  		ifp->if_nextents++;
2248  
2249  		if (cur == NULL)
2250  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2251  		else {
2252  			rval = XFS_ILOG_CORE;
2253  			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2254  			if (error)
2255  				goto done;
2256  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2257  				error = -EFSCORRUPTED;
2258  				goto done;
2259  			}
2260  			error = xfs_bmbt_update(cur, &PREV);
2261  			if (error)
2262  				goto done;
2263  			cur->bc_rec.b = *new;
2264  			if ((error = xfs_btree_insert(cur, &i)))
2265  				goto done;
2266  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2267  				error = -EFSCORRUPTED;
2268  				goto done;
2269  			}
2270  		}
2271  		break;
2272  
2273  	case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2274  		/*
2275  		 * Setting the last part of a previous oldext extent to newext.
2276  		 * The right neighbor is contiguous with the new allocation.
2277  		 */
2278  		old = PREV;
2279  		PREV.br_blockcount -= new->br_blockcount;
2280  
2281  		RIGHT.br_startoff = new->br_startoff;
2282  		RIGHT.br_startblock = new->br_startblock;
2283  		RIGHT.br_blockcount += new->br_blockcount;
2284  
2285  		xfs_iext_update_extent(ip, state, icur, &PREV);
2286  		xfs_iext_next(ifp, icur);
2287  		xfs_iext_update_extent(ip, state, icur, &RIGHT);
2288  
2289  		if (cur == NULL)
2290  			rval = XFS_ILOG_DEXT;
2291  		else {
2292  			rval = 0;
2293  			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2294  			if (error)
2295  				goto done;
2296  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2297  				error = -EFSCORRUPTED;
2298  				goto done;
2299  			}
2300  			error = xfs_bmbt_update(cur, &PREV);
2301  			if (error)
2302  				goto done;
2303  			error = xfs_btree_increment(cur, 0, &i);
2304  			if (error)
2305  				goto done;
2306  			error = xfs_bmbt_update(cur, &RIGHT);
2307  			if (error)
2308  				goto done;
2309  		}
2310  		break;
2311  
2312  	case BMAP_RIGHT_FILLING:
2313  		/*
2314  		 * Setting the last part of a previous oldext extent to newext.
2315  		 * The right neighbor is not contiguous.
2316  		 */
2317  		old = PREV;
2318  		PREV.br_blockcount -= new->br_blockcount;
2319  
2320  		xfs_iext_update_extent(ip, state, icur, &PREV);
2321  		xfs_iext_next(ifp, icur);
2322  		xfs_iext_insert(ip, icur, new, state);
2323  		ifp->if_nextents++;
2324  
2325  		if (cur == NULL)
2326  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2327  		else {
2328  			rval = XFS_ILOG_CORE;
2329  			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2330  			if (error)
2331  				goto done;
2332  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2333  				error = -EFSCORRUPTED;
2334  				goto done;
2335  			}
2336  			error = xfs_bmbt_update(cur, &PREV);
2337  			if (error)
2338  				goto done;
2339  			error = xfs_bmbt_lookup_eq(cur, new, &i);
2340  			if (error)
2341  				goto done;
2342  			if (XFS_IS_CORRUPT(mp, i != 0)) {
2343  				error = -EFSCORRUPTED;
2344  				goto done;
2345  			}
2346  			if ((error = xfs_btree_insert(cur, &i)))
2347  				goto done;
2348  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2349  				error = -EFSCORRUPTED;
2350  				goto done;
2351  			}
2352  		}
2353  		break;
2354  
2355  	case 0:
2356  		/*
2357  		 * Setting the middle part of a previous oldext extent to
2358  		 * newext.  Contiguity is impossible here.
2359  		 * One extent becomes three extents.
2360  		 */
2361  		old = PREV;
2362  		PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
2363  
2364  		r[0] = *new;
2365  		r[1].br_startoff = new_endoff;
2366  		r[1].br_blockcount =
2367  			old.br_startoff + old.br_blockcount - new_endoff;
2368  		r[1].br_startblock = new->br_startblock + new->br_blockcount;
2369  		r[1].br_state = PREV.br_state;
2370  
2371  		xfs_iext_update_extent(ip, state, icur, &PREV);
2372  		xfs_iext_next(ifp, icur);
2373  		xfs_iext_insert(ip, icur, &r[1], state);
2374  		xfs_iext_insert(ip, icur, &r[0], state);
2375  		ifp->if_nextents += 2;
2376  
2377  		if (cur == NULL)
2378  			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2379  		else {
2380  			rval = XFS_ILOG_CORE;
2381  			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2382  			if (error)
2383  				goto done;
2384  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2385  				error = -EFSCORRUPTED;
2386  				goto done;
2387  			}
2388  			/* new right extent - oldext */
2389  			error = xfs_bmbt_update(cur, &r[1]);
2390  			if (error)
2391  				goto done;
2392  			/* new left extent - oldext */
2393  			cur->bc_rec.b = PREV;
2394  			if ((error = xfs_btree_insert(cur, &i)))
2395  				goto done;
2396  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2397  				error = -EFSCORRUPTED;
2398  				goto done;
2399  			}
2400  			/*
2401  			 * Reset the cursor to the position of the new extent
2402  			 * we are about to insert as we can't trust it after
2403  			 * the previous insert.
2404  			 */
2405  			error = xfs_bmbt_lookup_eq(cur, new, &i);
2406  			if (error)
2407  				goto done;
2408  			if (XFS_IS_CORRUPT(mp, i != 0)) {
2409  				error = -EFSCORRUPTED;
2410  				goto done;
2411  			}
2412  			/* new middle extent - newext */
2413  			if ((error = xfs_btree_insert(cur, &i)))
2414  				goto done;
2415  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2416  				error = -EFSCORRUPTED;
2417  				goto done;
2418  			}
2419  		}
2420  		break;
2421  
2422  	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2423  	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2424  	case BMAP_LEFT_FILLING | BMAP_RIGHT_CONTIG:
2425  	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
2426  	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2427  	case BMAP_LEFT_CONTIG:
2428  	case BMAP_RIGHT_CONTIG:
2429  		/*
2430  		 * These cases are all impossible.
2431  		 */
2432  		ASSERT(0);
2433  	}
2434  
2435  	/* update reverse mappings */
2436  	xfs_rmap_convert_extent(mp, tp, ip, whichfork, new);
2437  
2438  	/* convert to a btree if necessary */
2439  	if (xfs_bmap_needs_btree(ip, whichfork)) {
2440  		int	tmp_logflags;	/* partial log flag return val */
2441  
2442  		ASSERT(cur == NULL);
2443  		error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
2444  				&tmp_logflags, whichfork);
2445  		*logflagsp |= tmp_logflags;
2446  		if (error)
2447  			goto done;
2448  	}
2449  
2450  	/* clear out the allocated field, done with it now in any case. */
2451  	if (cur) {
2452  		cur->bc_ino.allocated = 0;
2453  		*curp = cur;
2454  	}
2455  
2456  	xfs_bmap_check_leaf_extents(*curp, ip, whichfork);
2457  done:
2458  	*logflagsp |= rval;
2459  	return error;
2460  #undef	LEFT
2461  #undef	RIGHT
2462  #undef	PREV
2463  }
2464  
2465  /*
2466   * Convert a hole to a delayed allocation.
2467   */
2468  STATIC void
2469  xfs_bmap_add_extent_hole_delay(
2470  	xfs_inode_t		*ip,	/* incore inode pointer */
2471  	int			whichfork,
2472  	struct xfs_iext_cursor	*icur,
2473  	xfs_bmbt_irec_t		*new)	/* new data to add to file extents */
2474  {
2475  	struct xfs_ifork	*ifp;	/* inode fork pointer */
2476  	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
2477  	xfs_filblks_t		newlen=0;	/* new indirect size */
2478  	xfs_filblks_t		oldlen=0;	/* old indirect size */
2479  	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
2480  	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
2481  	xfs_filblks_t		temp;	 /* temp for indirect calculations */
2482  
2483  	ifp = XFS_IFORK_PTR(ip, whichfork);
2484  	ASSERT(isnullstartblock(new->br_startblock));
2485  
2486  	/*
2487  	 * Check and set flags if this segment has a left neighbor
2488  	 */
2489  	if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
2490  		state |= BMAP_LEFT_VALID;
2491  		if (isnullstartblock(left.br_startblock))
2492  			state |= BMAP_LEFT_DELAY;
2493  	}
2494  
2495  	/*
2496  	 * Check and set flags if the current (right) segment exists.
2497  	 * If it doesn't exist, we're converting the hole at end-of-file.
2498  	 */
2499  	if (xfs_iext_get_extent(ifp, icur, &right)) {
2500  		state |= BMAP_RIGHT_VALID;
2501  		if (isnullstartblock(right.br_startblock))
2502  			state |= BMAP_RIGHT_DELAY;
2503  	}
2504  
2505  	/*
2506  	 * Set contiguity flags on the left and right neighbors.
2507  	 * Don't let extents get too large, even if the pieces are contiguous.
2508  	 */
2509  	if ((state & BMAP_LEFT_VALID) && (state & BMAP_LEFT_DELAY) &&
2510  	    left.br_startoff + left.br_blockcount == new->br_startoff &&
2511  	    left.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2512  		state |= BMAP_LEFT_CONTIG;
2513  
2514  	if ((state & BMAP_RIGHT_VALID) && (state & BMAP_RIGHT_DELAY) &&
2515  	    new->br_startoff + new->br_blockcount == right.br_startoff &&
2516  	    new->br_blockcount + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2517  	    (!(state & BMAP_LEFT_CONTIG) ||
2518  	     (left.br_blockcount + new->br_blockcount +
2519  	      right.br_blockcount <= XFS_MAX_BMBT_EXTLEN)))
2520  		state |= BMAP_RIGHT_CONTIG;
2521  
2522  	/*
2523  	 * Switch out based on the contiguity flags.
2524  	 */
2525  	switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
2526  	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2527  		/*
2528  		 * New allocation is contiguous with delayed allocations
2529  		 * on the left and on the right.
2530  		 * Merge all three into a single extent record.
2531  		 */
2532  		temp = left.br_blockcount + new->br_blockcount +
2533  			right.br_blockcount;
2534  
2535  		oldlen = startblockval(left.br_startblock) +
2536  			startblockval(new->br_startblock) +
2537  			startblockval(right.br_startblock);
2538  		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2539  					 oldlen);
2540  		left.br_startblock = nullstartblock(newlen);
2541  		left.br_blockcount = temp;
2542  
2543  		xfs_iext_remove(ip, icur, state);
2544  		xfs_iext_prev(ifp, icur);
2545  		xfs_iext_update_extent(ip, state, icur, &left);
2546  		break;
2547  
2548  	case BMAP_LEFT_CONTIG:
2549  		/*
2550  		 * New allocation is contiguous with a delayed allocation
2551  		 * on the left.
2552  		 * Merge the new allocation with the left neighbor.
2553  		 */
2554  		temp = left.br_blockcount + new->br_blockcount;
2555  
2556  		oldlen = startblockval(left.br_startblock) +
2557  			startblockval(new->br_startblock);
2558  		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2559  					 oldlen);
2560  		left.br_blockcount = temp;
2561  		left.br_startblock = nullstartblock(newlen);
2562  
2563  		xfs_iext_prev(ifp, icur);
2564  		xfs_iext_update_extent(ip, state, icur, &left);
2565  		break;
2566  
2567  	case BMAP_RIGHT_CONTIG:
2568  		/*
2569  		 * New allocation is contiguous with a delayed allocation
2570  		 * on the right.
2571  		 * Merge the new allocation with the right neighbor.
2572  		 */
2573  		temp = new->br_blockcount + right.br_blockcount;
2574  		oldlen = startblockval(new->br_startblock) +
2575  			startblockval(right.br_startblock);
2576  		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2577  					 oldlen);
2578  		right.br_startoff = new->br_startoff;
2579  		right.br_startblock = nullstartblock(newlen);
2580  		right.br_blockcount = temp;
2581  		xfs_iext_update_extent(ip, state, icur, &right);
2582  		break;
2583  
2584  	case 0:
2585  		/*
2586  		 * New allocation is not contiguous with another
2587  		 * delayed allocation.
2588  		 * Insert a new entry.
2589  		 */
2590  		oldlen = newlen = 0;
2591  		xfs_iext_insert(ip, icur, new, state);
2592  		break;
2593  	}
2594  	if (oldlen != newlen) {
2595  		ASSERT(oldlen > newlen);
2596  		xfs_mod_fdblocks(ip->i_mount, (int64_t)(oldlen - newlen),
2597  				 false);
2598  		/*
2599  		 * Nothing to do for disk quota accounting here.
2600  		 */
2601  		xfs_mod_delalloc(ip->i_mount, (int64_t)newlen - oldlen);
2602  	}
2603  }
2604  
2605  /*
2606   * Convert a hole to a real allocation.
2607   */
2608  STATIC int				/* error */
2609  xfs_bmap_add_extent_hole_real(
2610  	struct xfs_trans	*tp,
2611  	struct xfs_inode	*ip,
2612  	int			whichfork,
2613  	struct xfs_iext_cursor	*icur,
2614  	struct xfs_btree_cur	**curp,
2615  	struct xfs_bmbt_irec	*new,
2616  	int			*logflagsp,
2617  	uint32_t		flags)
2618  {
2619  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
2620  	struct xfs_mount	*mp = ip->i_mount;
2621  	struct xfs_btree_cur	*cur = *curp;
2622  	int			error;	/* error return value */
2623  	int			i;	/* temp state */
2624  	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
2625  	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
2626  	int			rval=0;	/* return value (logging flags) */
2627  	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
2628  	struct xfs_bmbt_irec	old;
2629  
2630  	ASSERT(!isnullstartblock(new->br_startblock));
2631  	ASSERT(!cur || !(cur->bc_ino.flags & XFS_BTCUR_BMBT_WASDEL));
2632  
2633  	XFS_STATS_INC(mp, xs_add_exlist);
2634  
2635  	/*
2636  	 * Check and set flags if this segment has a left neighbor.
2637  	 */
2638  	if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
2639  		state |= BMAP_LEFT_VALID;
2640  		if (isnullstartblock(left.br_startblock))
2641  			state |= BMAP_LEFT_DELAY;
2642  	}
2643  
2644  	/*
2645  	 * Check and set flags if this segment has a current value.
2646  	 * Not true if we're inserting into the "hole" at eof.
2647  	 */
2648  	if (xfs_iext_get_extent(ifp, icur, &right)) {
2649  		state |= BMAP_RIGHT_VALID;
2650  		if (isnullstartblock(right.br_startblock))
2651  			state |= BMAP_RIGHT_DELAY;
2652  	}
2653  
2654  	/*
2655  	 * We're inserting a real allocation between "left" and "right".
2656  	 * Set the contiguity flags.  Don't let extents get too large.
2657  	 */
2658  	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
2659  	    left.br_startoff + left.br_blockcount == new->br_startoff &&
2660  	    left.br_startblock + left.br_blockcount == new->br_startblock &&
2661  	    left.br_state == new->br_state &&
2662  	    left.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2663  		state |= BMAP_LEFT_CONTIG;
2664  
2665  	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
2666  	    new->br_startoff + new->br_blockcount == right.br_startoff &&
2667  	    new->br_startblock + new->br_blockcount == right.br_startblock &&
2668  	    new->br_state == right.br_state &&
2669  	    new->br_blockcount + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2670  	    (!(state & BMAP_LEFT_CONTIG) ||
2671  	     left.br_blockcount + new->br_blockcount +
2672  	     right.br_blockcount <= XFS_MAX_BMBT_EXTLEN))
2673  		state |= BMAP_RIGHT_CONTIG;
2674  
2675  	error = 0;
2676  	/*
2677  	 * Select which case we're in here, and implement it.
2678  	 */
2679  	switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
2680  	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2681  		/*
2682  		 * New allocation is contiguous with real allocations on the
2683  		 * left and on the right.
2684  		 * Merge all three into a single extent record.
2685  		 */
2686  		left.br_blockcount += new->br_blockcount + right.br_blockcount;
2687  
2688  		xfs_iext_remove(ip, icur, state);
2689  		xfs_iext_prev(ifp, icur);
2690  		xfs_iext_update_extent(ip, state, icur, &left);
2691  		ifp->if_nextents--;
2692  
2693  		if (cur == NULL) {
2694  			rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
2695  		} else {
2696  			rval = XFS_ILOG_CORE;
2697  			error = xfs_bmbt_lookup_eq(cur, &right, &i);
2698  			if (error)
2699  				goto done;
2700  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2701  				error = -EFSCORRUPTED;
2702  				goto done;
2703  			}
2704  			error = xfs_btree_delete(cur, &i);
2705  			if (error)
2706  				goto done;
2707  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2708  				error = -EFSCORRUPTED;
2709  				goto done;
2710  			}
2711  			error = xfs_btree_decrement(cur, 0, &i);
2712  			if (error)
2713  				goto done;
2714  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2715  				error = -EFSCORRUPTED;
2716  				goto done;
2717  			}
2718  			error = xfs_bmbt_update(cur, &left);
2719  			if (error)
2720  				goto done;
2721  		}
2722  		break;
2723  
2724  	case BMAP_LEFT_CONTIG:
2725  		/*
2726  		 * New allocation is contiguous with a real allocation
2727  		 * on the left.
2728  		 * Merge the new allocation with the left neighbor.
2729  		 */
2730  		old = left;
2731  		left.br_blockcount += new->br_blockcount;
2732  
2733  		xfs_iext_prev(ifp, icur);
2734  		xfs_iext_update_extent(ip, state, icur, &left);
2735  
2736  		if (cur == NULL) {
2737  			rval = xfs_ilog_fext(whichfork);
2738  		} else {
2739  			rval = 0;
2740  			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2741  			if (error)
2742  				goto done;
2743  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2744  				error = -EFSCORRUPTED;
2745  				goto done;
2746  			}
2747  			error = xfs_bmbt_update(cur, &left);
2748  			if (error)
2749  				goto done;
2750  		}
2751  		break;
2752  
2753  	case BMAP_RIGHT_CONTIG:
2754  		/*
2755  		 * New allocation is contiguous with a real allocation
2756  		 * on the right.
2757  		 * Merge the new allocation with the right neighbor.
2758  		 */
2759  		old = right;
2760  
2761  		right.br_startoff = new->br_startoff;
2762  		right.br_startblock = new->br_startblock;
2763  		right.br_blockcount += new->br_blockcount;
2764  		xfs_iext_update_extent(ip, state, icur, &right);
2765  
2766  		if (cur == NULL) {
2767  			rval = xfs_ilog_fext(whichfork);
2768  		} else {
2769  			rval = 0;
2770  			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2771  			if (error)
2772  				goto done;
2773  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2774  				error = -EFSCORRUPTED;
2775  				goto done;
2776  			}
2777  			error = xfs_bmbt_update(cur, &right);
2778  			if (error)
2779  				goto done;
2780  		}
2781  		break;
2782  
2783  	case 0:
2784  		/*
2785  		 * New allocation is not contiguous with another
2786  		 * real allocation.
2787  		 * Insert a new entry.
2788  		 */
2789  		xfs_iext_insert(ip, icur, new, state);
2790  		ifp->if_nextents++;
2791  
2792  		if (cur == NULL) {
2793  			rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
2794  		} else {
2795  			rval = XFS_ILOG_CORE;
2796  			error = xfs_bmbt_lookup_eq(cur, new, &i);
2797  			if (error)
2798  				goto done;
2799  			if (XFS_IS_CORRUPT(mp, i != 0)) {
2800  				error = -EFSCORRUPTED;
2801  				goto done;
2802  			}
2803  			error = xfs_btree_insert(cur, &i);
2804  			if (error)
2805  				goto done;
2806  			if (XFS_IS_CORRUPT(mp, i != 1)) {
2807  				error = -EFSCORRUPTED;
2808  				goto done;
2809  			}
2810  		}
2811  		break;
2812  	}
2813  
2814  	/* add reverse mapping unless caller opted out */
2815  	if (!(flags & XFS_BMAPI_NORMAP))
2816  		xfs_rmap_map_extent(tp, ip, whichfork, new);
2817  
2818  	/* convert to a btree if necessary */
2819  	if (xfs_bmap_needs_btree(ip, whichfork)) {
2820  		int	tmp_logflags;	/* partial log flag return val */
2821  
2822  		ASSERT(cur == NULL);
2823  		error = xfs_bmap_extents_to_btree(tp, ip, curp, 0,
2824  				&tmp_logflags, whichfork);
2825  		*logflagsp |= tmp_logflags;
2826  		cur = *curp;
2827  		if (error)
2828  			goto done;
2829  	}
2830  
2831  	/* clear out the allocated field, done with it now in any case. */
2832  	if (cur)
2833  		cur->bc_ino.allocated = 0;
2834  
2835  	xfs_bmap_check_leaf_extents(cur, ip, whichfork);
2836  done:
2837  	*logflagsp |= rval;
2838  	return error;
2839  }
2840  
2841  /*
2842   * Functions used in the extent read, allocate and remove paths
2843   */
2844  
2845  /*
2846   * Adjust the size of the new extent based on i_extsize and rt extsize.
2847   */
2848  int
2849  xfs_bmap_extsize_align(
2850  	xfs_mount_t	*mp,
2851  	xfs_bmbt_irec_t	*gotp,		/* next extent pointer */
2852  	xfs_bmbt_irec_t	*prevp,		/* previous extent pointer */
2853  	xfs_extlen_t	extsz,		/* align to this extent size */
2854  	int		rt,		/* is this a realtime inode? */
2855  	int		eof,		/* is extent at end-of-file? */
2856  	int		delay,		/* creating delalloc extent? */
2857  	int		convert,	/* overwriting unwritten extent? */
2858  	xfs_fileoff_t	*offp,		/* in/out: aligned offset */
2859  	xfs_extlen_t	*lenp)		/* in/out: aligned length */
2860  {
2861  	xfs_fileoff_t	orig_off;	/* original offset */
2862  	xfs_extlen_t	orig_alen;	/* original length */
2863  	xfs_fileoff_t	orig_end;	/* original off+len */
2864  	xfs_fileoff_t	nexto;		/* next file offset */
2865  	xfs_fileoff_t	prevo;		/* previous file offset */
2866  	xfs_fileoff_t	align_off;	/* temp for offset */
2867  	xfs_extlen_t	align_alen;	/* temp for length */
2868  	xfs_extlen_t	temp;		/* temp for calculations */
2869  
2870  	if (convert)
2871  		return 0;
2872  
2873  	orig_off = align_off = *offp;
2874  	orig_alen = align_alen = *lenp;
2875  	orig_end = orig_off + orig_alen;
2876  
2877  	/*
2878  	 * If this request overlaps an existing extent, then don't
2879  	 * attempt to perform any additional alignment.
2880  	 */
2881  	if (!delay && !eof &&
2882  	    (orig_off >= gotp->br_startoff) &&
2883  	    (orig_end <= gotp->br_startoff + gotp->br_blockcount)) {
2884  		return 0;
2885  	}
2886  
2887  	/*
2888  	 * If the file offset is unaligned vs. the extent size
2889  	 * we need to align it.  This will be possible unless
2890  	 * the file was previously written with a kernel that didn't
2891  	 * perform this alignment, or if a truncate shot us in the
2892  	 * foot.
2893  	 */
2894  	div_u64_rem(orig_off, extsz, &temp);
2895  	if (temp) {
2896  		align_alen += temp;
2897  		align_off -= temp;
2898  	}
2899  
2900  	/* Same adjustment for the end of the requested area. */
2901  	temp = (align_alen % extsz);
2902  	if (temp)
2903  		align_alen += extsz - temp;
2904  
2905  	/*
2906  	 * For large extent hint sizes, the aligned extent might be larger than
2907  	 * XFS_BMBT_MAX_EXTLEN. In that case, reduce the size by an extsz so
2908  	 * that it pulls the length back under XFS_BMBT_MAX_EXTLEN. The outer
2909  	 * allocation loops handle short allocation just fine, so it is safe to
2910  	 * do this. We only want to do it when we are forced to, though, because
2911  	 * it means more allocation operations are required.
2912  	 */
2913  	while (align_alen > XFS_MAX_BMBT_EXTLEN)
2914  		align_alen -= extsz;
2915  	ASSERT(align_alen <= XFS_MAX_BMBT_EXTLEN);
2916  
2917  	/*
2918  	 * If the previous block overlaps with this proposed allocation
2919  	 * then move the start forward without adjusting the length.
2920  	 */
2921  	if (prevp->br_startoff != NULLFILEOFF) {
2922  		if (prevp->br_startblock == HOLESTARTBLOCK)
2923  			prevo = prevp->br_startoff;
2924  		else
2925  			prevo = prevp->br_startoff + prevp->br_blockcount;
2926  	} else
2927  		prevo = 0;
2928  	if (align_off != orig_off && align_off < prevo)
2929  		align_off = prevo;
2930  	/*
2931  	 * If the next block overlaps with this proposed allocation
2932  	 * then move the start back without adjusting the length,
2933  	 * but not before offset 0.
2934  	 * This may of course make the start overlap previous block,
2935  	 * and if we hit the offset 0 limit then the next block
2936  	 * can still overlap too.
2937  	 */
2938  	if (!eof && gotp->br_startoff != NULLFILEOFF) {
2939  		if ((delay && gotp->br_startblock == HOLESTARTBLOCK) ||
2940  		    (!delay && gotp->br_startblock == DELAYSTARTBLOCK))
2941  			nexto = gotp->br_startoff + gotp->br_blockcount;
2942  		else
2943  			nexto = gotp->br_startoff;
2944  	} else
2945  		nexto = NULLFILEOFF;
2946  	if (!eof &&
2947  	    align_off + align_alen != orig_end &&
2948  	    align_off + align_alen > nexto)
2949  		align_off = nexto > align_alen ? nexto - align_alen : 0;
2950  	/*
2951  	 * If we're now overlapping the next or previous extent that
2952  	 * means we can't fit an extsz piece in this hole.  Just move
2953  	 * the start forward to the first valid spot and set
2954  	 * the length so we hit the end.
2955  	 */
2956  	if (align_off != orig_off && align_off < prevo)
2957  		align_off = prevo;
2958  	if (align_off + align_alen != orig_end &&
2959  	    align_off + align_alen > nexto &&
2960  	    nexto != NULLFILEOFF) {
2961  		ASSERT(nexto > prevo);
2962  		align_alen = nexto - align_off;
2963  	}
2964  
2965  	/*
2966  	 * If realtime, and the result isn't a multiple of the realtime
2967  	 * extent size we need to remove blocks until it is.
2968  	 */
2969  	if (rt && (temp = (align_alen % mp->m_sb.sb_rextsize))) {
2970  		/*
2971  		 * We're not covering the original request, or
2972  		 * we won't be able to once we fix the length.
2973  		 */
2974  		if (orig_off < align_off ||
2975  		    orig_end > align_off + align_alen ||
2976  		    align_alen - temp < orig_alen)
2977  			return -EINVAL;
2978  		/*
2979  		 * Try to fix it by moving the start up.
2980  		 */
2981  		if (align_off + temp <= orig_off) {
2982  			align_alen -= temp;
2983  			align_off += temp;
2984  		}
2985  		/*
2986  		 * Try to fix it by moving the end in.
2987  		 */
2988  		else if (align_off + align_alen - temp >= orig_end)
2989  			align_alen -= temp;
2990  		/*
2991  		 * Set the start to the minimum then trim the length.
2992  		 */
2993  		else {
2994  			align_alen -= orig_off - align_off;
2995  			align_off = orig_off;
2996  			align_alen -= align_alen % mp->m_sb.sb_rextsize;
2997  		}
2998  		/*
2999  		 * Result doesn't cover the request, fail it.
3000  		 */
3001  		if (orig_off < align_off || orig_end > align_off + align_alen)
3002  			return -EINVAL;
3003  	} else {
3004  		ASSERT(orig_off >= align_off);
3005  		/* see XFS_BMBT_MAX_EXTLEN handling above */
3006  		ASSERT(orig_end <= align_off + align_alen ||
3007  		       align_alen + extsz > XFS_MAX_BMBT_EXTLEN);
3008  	}
3009  
3010  #ifdef DEBUG
3011  	if (!eof && gotp->br_startoff != NULLFILEOFF)
3012  		ASSERT(align_off + align_alen <= gotp->br_startoff);
3013  	if (prevp->br_startoff != NULLFILEOFF)
3014  		ASSERT(align_off >= prevp->br_startoff + prevp->br_blockcount);
3015  #endif
3016  
3017  	*lenp = align_alen;
3018  	*offp = align_off;
3019  	return 0;
3020  }
3021  
3022  #define XFS_ALLOC_GAP_UNITS	4
3023  
3024  void
3025  xfs_bmap_adjacent(
3026  	struct xfs_bmalloca	*ap)	/* bmap alloc argument struct */
3027  {
3028  	xfs_fsblock_t	adjust;		/* adjustment to block numbers */
3029  	xfs_agnumber_t	fb_agno;	/* ag number of ap->firstblock */
3030  	xfs_mount_t	*mp;		/* mount point structure */
3031  	int		nullfb;		/* true if ap->firstblock isn't set */
3032  	int		rt;		/* true if inode is realtime */
3033  
3034  #define	ISVALID(x,y)	\
3035  	(rt ? \
3036  		(x) < mp->m_sb.sb_rblocks : \
3037  		XFS_FSB_TO_AGNO(mp, x) == XFS_FSB_TO_AGNO(mp, y) && \
3038  		XFS_FSB_TO_AGNO(mp, x) < mp->m_sb.sb_agcount && \
3039  		XFS_FSB_TO_AGBNO(mp, x) < mp->m_sb.sb_agblocks)
3040  
3041  	mp = ap->ip->i_mount;
3042  	nullfb = ap->tp->t_firstblock == NULLFSBLOCK;
3043  	rt = XFS_IS_REALTIME_INODE(ap->ip) &&
3044  		(ap->datatype & XFS_ALLOC_USERDATA);
3045  	fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp,
3046  							ap->tp->t_firstblock);
3047  	/*
3048  	 * If allocating at eof, and there's a previous real block,
3049  	 * try to use its last block as our starting point.
3050  	 */
3051  	if (ap->eof && ap->prev.br_startoff != NULLFILEOFF &&
3052  	    !isnullstartblock(ap->prev.br_startblock) &&
3053  	    ISVALID(ap->prev.br_startblock + ap->prev.br_blockcount,
3054  		    ap->prev.br_startblock)) {
3055  		ap->blkno = ap->prev.br_startblock + ap->prev.br_blockcount;
3056  		/*
3057  		 * Adjust for the gap between prevp and us.
3058  		 */
3059  		adjust = ap->offset -
3060  			(ap->prev.br_startoff + ap->prev.br_blockcount);
3061  		if (adjust &&
3062  		    ISVALID(ap->blkno + adjust, ap->prev.br_startblock))
3063  			ap->blkno += adjust;
3064  	}
3065  	/*
3066  	 * If not at eof, then compare the two neighbor blocks.
3067  	 * Figure out whether either one gives us a good starting point,
3068  	 * and pick the better one.
3069  	 */
3070  	else if (!ap->eof) {
3071  		xfs_fsblock_t	gotbno;		/* right side block number */
3072  		xfs_fsblock_t	gotdiff=0;	/* right side difference */
3073  		xfs_fsblock_t	prevbno;	/* left side block number */
3074  		xfs_fsblock_t	prevdiff=0;	/* left side difference */
3075  
3076  		/*
3077  		 * If there's a previous (left) block, select a requested
3078  		 * start block based on it.
3079  		 */
3080  		if (ap->prev.br_startoff != NULLFILEOFF &&
3081  		    !isnullstartblock(ap->prev.br_startblock) &&
3082  		    (prevbno = ap->prev.br_startblock +
3083  			       ap->prev.br_blockcount) &&
3084  		    ISVALID(prevbno, ap->prev.br_startblock)) {
3085  			/*
3086  			 * Calculate gap to end of previous block.
3087  			 */
3088  			adjust = prevdiff = ap->offset -
3089  				(ap->prev.br_startoff +
3090  				 ap->prev.br_blockcount);
3091  			/*
3092  			 * Figure the startblock based on the previous block's
3093  			 * end and the gap size.
3094  			 * Heuristic!
3095  			 * If the gap is large relative to the piece we're
3096  			 * allocating, or using it gives us an invalid block
3097  			 * number, then just use the end of the previous block.
3098  			 */
3099  			if (prevdiff <= XFS_ALLOC_GAP_UNITS * ap->length &&
3100  			    ISVALID(prevbno + prevdiff,
3101  				    ap->prev.br_startblock))
3102  				prevbno += adjust;
3103  			else
3104  				prevdiff += adjust;
3105  			/*
3106  			 * If the firstblock forbids it, can't use it,
3107  			 * must use default.
3108  			 */
3109  			if (!rt && !nullfb &&
3110  			    XFS_FSB_TO_AGNO(mp, prevbno) != fb_agno)
3111  				prevbno = NULLFSBLOCK;
3112  		}
3113  		/*
3114  		 * No previous block or can't follow it, just default.
3115  		 */
3116  		else
3117  			prevbno = NULLFSBLOCK;
3118  		/*
3119  		 * If there's a following (right) block, select a requested
3120  		 * start block based on it.
3121  		 */
3122  		if (!isnullstartblock(ap->got.br_startblock)) {
3123  			/*
3124  			 * Calculate gap to start of next block.
3125  			 */
3126  			adjust = gotdiff = ap->got.br_startoff - ap->offset;
3127  			/*
3128  			 * Figure the startblock based on the next block's
3129  			 * start and the gap size.
3130  			 */
3131  			gotbno = ap->got.br_startblock;
3132  			/*
3133  			 * Heuristic!
3134  			 * If the gap is large relative to the piece we're
3135  			 * allocating, or using it gives us an invalid block
3136  			 * number, then just use the start of the next block
3137  			 * offset by our length.
3138  			 */
3139  			if (gotdiff <= XFS_ALLOC_GAP_UNITS * ap->length &&
3140  			    ISVALID(gotbno - gotdiff, gotbno))
3141  				gotbno -= adjust;
3142  			else if (ISVALID(gotbno - ap->length, gotbno)) {
3143  				gotbno -= ap->length;
3144  				gotdiff += adjust - ap->length;
3145  			} else
3146  				gotdiff += adjust;
3147  			/*
3148  			 * If the firstblock forbids it, can't use it,
3149  			 * must use default.
3150  			 */
3151  			if (!rt && !nullfb &&
3152  			    XFS_FSB_TO_AGNO(mp, gotbno) != fb_agno)
3153  				gotbno = NULLFSBLOCK;
3154  		}
3155  		/*
3156  		 * No next block, just default.
3157  		 */
3158  		else
3159  			gotbno = NULLFSBLOCK;
3160  		/*
3161  		 * If both valid, pick the better one, else the only good
3162  		 * one, else ap->blkno is already set (to 0 or the inode block).
3163  		 */
3164  		if (prevbno != NULLFSBLOCK && gotbno != NULLFSBLOCK)
3165  			ap->blkno = prevdiff <= gotdiff ? prevbno : gotbno;
3166  		else if (prevbno != NULLFSBLOCK)
3167  			ap->blkno = prevbno;
3168  		else if (gotbno != NULLFSBLOCK)
3169  			ap->blkno = gotbno;
3170  	}
3171  #undef ISVALID
3172  }
3173  
3174  static int
3175  xfs_bmap_longest_free_extent(
3176  	struct xfs_trans	*tp,
3177  	xfs_agnumber_t		ag,
3178  	xfs_extlen_t		*blen,
3179  	int			*notinit)
3180  {
3181  	struct xfs_mount	*mp = tp->t_mountp;
3182  	struct xfs_perag	*pag;
3183  	xfs_extlen_t		longest;
3184  	int			error = 0;
3185  
3186  	pag = xfs_perag_get(mp, ag);
3187  	if (!pag->pagf_init) {
3188  		error = xfs_alloc_pagf_init(mp, tp, ag, XFS_ALLOC_FLAG_TRYLOCK);
3189  		if (error) {
3190  			/* Couldn't lock the AGF, so skip this AG. */
3191  			if (error == -EAGAIN) {
3192  				*notinit = 1;
3193  				error = 0;
3194  			}
3195  			goto out;
3196  		}
3197  	}
3198  
3199  	longest = xfs_alloc_longest_free_extent(pag,
3200  				xfs_alloc_min_freelist(mp, pag),
3201  				xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE));
3202  	if (*blen < longest)
3203  		*blen = longest;
3204  
3205  out:
3206  	xfs_perag_put(pag);
3207  	return error;
3208  }
3209  
3210  static void
3211  xfs_bmap_select_minlen(
3212  	struct xfs_bmalloca	*ap,
3213  	struct xfs_alloc_arg	*args,
3214  	xfs_extlen_t		*blen,
3215  	int			notinit)
3216  {
3217  	if (notinit || *blen < ap->minlen) {
3218  		/*
3219  		 * Since we did a BUF_TRYLOCK above, it is possible that
3220  		 * there is space for this request.
3221  		 */
3222  		args->minlen = ap->minlen;
3223  	} else if (*blen < args->maxlen) {
3224  		/*
3225  		 * If the best seen length is less than the request length,
3226  		 * use the best as the minimum.
3227  		 */
3228  		args->minlen = *blen;
3229  	} else {
3230  		/*
3231  		 * Otherwise we've seen an extent as big as maxlen, use that
3232  		 * as the minimum.
3233  		 */
3234  		args->minlen = args->maxlen;
3235  	}
3236  }
3237  
3238  STATIC int
3239  xfs_bmap_btalloc_nullfb(
3240  	struct xfs_bmalloca	*ap,
3241  	struct xfs_alloc_arg	*args,
3242  	xfs_extlen_t		*blen)
3243  {
3244  	struct xfs_mount	*mp = ap->ip->i_mount;
3245  	xfs_agnumber_t		ag, startag;
3246  	int			notinit = 0;
3247  	int			error;
3248  
3249  	args->type = XFS_ALLOCTYPE_START_BNO;
3250  	args->total = ap->total;
3251  
3252  	startag = ag = XFS_FSB_TO_AGNO(mp, args->fsbno);
3253  	if (startag == NULLAGNUMBER)
3254  		startag = ag = 0;
3255  
3256  	while (*blen < args->maxlen) {
3257  		error = xfs_bmap_longest_free_extent(args->tp, ag, blen,
3258  						     &notinit);
3259  		if (error)
3260  			return error;
3261  
3262  		if (++ag == mp->m_sb.sb_agcount)
3263  			ag = 0;
3264  		if (ag == startag)
3265  			break;
3266  	}
3267  
3268  	xfs_bmap_select_minlen(ap, args, blen, notinit);
3269  	return 0;
3270  }
3271  
3272  STATIC int
3273  xfs_bmap_btalloc_filestreams(
3274  	struct xfs_bmalloca	*ap,
3275  	struct xfs_alloc_arg	*args,
3276  	xfs_extlen_t		*blen)
3277  {
3278  	struct xfs_mount	*mp = ap->ip->i_mount;
3279  	xfs_agnumber_t		ag;
3280  	int			notinit = 0;
3281  	int			error;
3282  
3283  	args->type = XFS_ALLOCTYPE_NEAR_BNO;
3284  	args->total = ap->total;
3285  
3286  	ag = XFS_FSB_TO_AGNO(mp, args->fsbno);
3287  	if (ag == NULLAGNUMBER)
3288  		ag = 0;
3289  
3290  	error = xfs_bmap_longest_free_extent(args->tp, ag, blen, &notinit);
3291  	if (error)
3292  		return error;
3293  
3294  	if (*blen < args->maxlen) {
3295  		error = xfs_filestream_new_ag(ap, &ag);
3296  		if (error)
3297  			return error;
3298  
3299  		error = xfs_bmap_longest_free_extent(args->tp, ag, blen,
3300  						     &notinit);
3301  		if (error)
3302  			return error;
3303  
3304  	}
3305  
3306  	xfs_bmap_select_minlen(ap, args, blen, notinit);
3307  
3308  	/*
3309  	 * Set the failure fallback case to look in the selected AG as stream
3310  	 * may have moved.
3311  	 */
3312  	ap->blkno = args->fsbno = XFS_AGB_TO_FSB(mp, ag, 0);
3313  	return 0;
3314  }
3315  
3316  /* Update all inode and quota accounting for the allocation we just did. */
3317  static void
3318  xfs_bmap_btalloc_accounting(
3319  	struct xfs_bmalloca	*ap,
3320  	struct xfs_alloc_arg	*args)
3321  {
3322  	if (ap->flags & XFS_BMAPI_COWFORK) {
3323  		/*
3324  		 * COW fork blocks are in-core only and thus are treated as
3325  		 * in-core quota reservation (like delalloc blocks) even when
3326  		 * converted to real blocks. The quota reservation is not
3327  		 * accounted to disk until blocks are remapped to the data
3328  		 * fork. So if these blocks were previously delalloc, we
3329  		 * already have quota reservation and there's nothing to do
3330  		 * yet.
3331  		 */
3332  		if (ap->wasdel) {
3333  			xfs_mod_delalloc(ap->ip->i_mount, -(int64_t)args->len);
3334  			return;
3335  		}
3336  
3337  		/*
3338  		 * Otherwise, we've allocated blocks in a hole. The transaction
3339  		 * has acquired in-core quota reservation for this extent.
3340  		 * Rather than account these as real blocks, however, we reduce
3341  		 * the transaction quota reservation based on the allocation.
3342  		 * This essentially transfers the transaction quota reservation
3343  		 * to that of a delalloc extent.
3344  		 */
3345  		ap->ip->i_delayed_blks += args->len;
3346  		xfs_trans_mod_dquot_byino(ap->tp, ap->ip, XFS_TRANS_DQ_RES_BLKS,
3347  				-(long)args->len);
3348  		return;
3349  	}
3350  
3351  	/* data/attr fork only */
3352  	ap->ip->i_nblocks += args->len;
3353  	xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
3354  	if (ap->wasdel) {
3355  		ap->ip->i_delayed_blks -= args->len;
3356  		xfs_mod_delalloc(ap->ip->i_mount, -(int64_t)args->len);
3357  	}
3358  	xfs_trans_mod_dquot_byino(ap->tp, ap->ip,
3359  		ap->wasdel ? XFS_TRANS_DQ_DELBCOUNT : XFS_TRANS_DQ_BCOUNT,
3360  		args->len);
3361  }
3362  
3363  static int
3364  xfs_bmap_compute_alignments(
3365  	struct xfs_bmalloca	*ap,
3366  	struct xfs_alloc_arg	*args)
3367  {
3368  	struct xfs_mount	*mp = args->mp;
3369  	xfs_extlen_t		align = 0; /* minimum allocation alignment */
3370  	int			stripe_align = 0;
3371  
3372  	/* stripe alignment for allocation is determined by mount parameters */
3373  	if (mp->m_swidth && xfs_has_swalloc(mp))
3374  		stripe_align = mp->m_swidth;
3375  	else if (mp->m_dalign)
3376  		stripe_align = mp->m_dalign;
3377  
3378  	if (ap->flags & XFS_BMAPI_COWFORK)
3379  		align = xfs_get_cowextsz_hint(ap->ip);
3380  	else if (ap->datatype & XFS_ALLOC_USERDATA)
3381  		align = xfs_get_extsz_hint(ap->ip);
3382  	if (align) {
3383  		if (xfs_bmap_extsize_align(mp, &ap->got, &ap->prev, align, 0,
3384  					ap->eof, 0, ap->conv, &ap->offset,
3385  					&ap->length))
3386  			ASSERT(0);
3387  		ASSERT(ap->length);
3388  	}
3389  
3390  	/* apply extent size hints if obtained earlier */
3391  	if (align) {
3392  		args->prod = align;
3393  		div_u64_rem(ap->offset, args->prod, &args->mod);
3394  		if (args->mod)
3395  			args->mod = args->prod - args->mod;
3396  	} else if (mp->m_sb.sb_blocksize >= PAGE_SIZE) {
3397  		args->prod = 1;
3398  		args->mod = 0;
3399  	} else {
3400  		args->prod = PAGE_SIZE >> mp->m_sb.sb_blocklog;
3401  		div_u64_rem(ap->offset, args->prod, &args->mod);
3402  		if (args->mod)
3403  			args->mod = args->prod - args->mod;
3404  	}
3405  
3406  	return stripe_align;
3407  }
3408  
3409  static void
3410  xfs_bmap_process_allocated_extent(
3411  	struct xfs_bmalloca	*ap,
3412  	struct xfs_alloc_arg	*args,
3413  	xfs_fileoff_t		orig_offset,
3414  	xfs_extlen_t		orig_length)
3415  {
3416  	int			nullfb;
3417  
3418  	nullfb = ap->tp->t_firstblock == NULLFSBLOCK;
3419  
3420  	/*
3421  	 * check the allocation happened at the same or higher AG than
3422  	 * the first block that was allocated.
3423  	 */
3424  	ASSERT(nullfb ||
3425  		XFS_FSB_TO_AGNO(args->mp, ap->tp->t_firstblock) <=
3426  		XFS_FSB_TO_AGNO(args->mp, args->fsbno));
3427  
3428  	ap->blkno = args->fsbno;
3429  	if (nullfb)
3430  		ap->tp->t_firstblock = args->fsbno;
3431  	ap->length = args->len;
3432  	/*
3433  	 * If the extent size hint is active, we tried to round the
3434  	 * caller's allocation request offset down to extsz and the
3435  	 * length up to another extsz boundary.  If we found a free
3436  	 * extent we mapped it in starting at this new offset.  If the
3437  	 * newly mapped space isn't long enough to cover any of the
3438  	 * range of offsets that was originally requested, move the
3439  	 * mapping up so that we can fill as much of the caller's
3440  	 * original request as possible.  Free space is apparently
3441  	 * very fragmented so we're unlikely to be able to satisfy the
3442  	 * hints anyway.
3443  	 */
3444  	if (ap->length <= orig_length)
3445  		ap->offset = orig_offset;
3446  	else if (ap->offset + ap->length < orig_offset + orig_length)
3447  		ap->offset = orig_offset + orig_length - ap->length;
3448  	xfs_bmap_btalloc_accounting(ap, args);
3449  }
3450  
3451  #ifdef DEBUG
3452  static int
3453  xfs_bmap_exact_minlen_extent_alloc(
3454  	struct xfs_bmalloca	*ap)
3455  {
3456  	struct xfs_mount	*mp = ap->ip->i_mount;
3457  	struct xfs_alloc_arg	args = { .tp = ap->tp, .mp = mp };
3458  	xfs_fileoff_t		orig_offset;
3459  	xfs_extlen_t		orig_length;
3460  	int			error;
3461  
3462  	ASSERT(ap->length);
3463  
3464  	if (ap->minlen != 1) {
3465  		ap->blkno = NULLFSBLOCK;
3466  		ap->length = 0;
3467  		return 0;
3468  	}
3469  
3470  	orig_offset = ap->offset;
3471  	orig_length = ap->length;
3472  
3473  	args.alloc_minlen_only = 1;
3474  
3475  	xfs_bmap_compute_alignments(ap, &args);
3476  
3477  	if (ap->tp->t_firstblock == NULLFSBLOCK) {
3478  		/*
3479  		 * Unlike the longest extent available in an AG, we don't track
3480  		 * the length of an AG's shortest extent.
3481  		 * XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT is a debug only knob and
3482  		 * hence we can afford to start traversing from the 0th AG since
3483  		 * we need not be concerned about a drop in performance in
3484  		 * "debug only" code paths.
3485  		 */
3486  		ap->blkno = XFS_AGB_TO_FSB(mp, 0, 0);
3487  	} else {
3488  		ap->blkno = ap->tp->t_firstblock;
3489  	}
3490  
3491  	args.fsbno = ap->blkno;
3492  	args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
3493  	args.type = XFS_ALLOCTYPE_FIRST_AG;
3494  	args.minlen = args.maxlen = ap->minlen;
3495  	args.total = ap->total;
3496  
3497  	args.alignment = 1;
3498  	args.minalignslop = 0;
3499  
3500  	args.minleft = ap->minleft;
3501  	args.wasdel = ap->wasdel;
3502  	args.resv = XFS_AG_RESV_NONE;
3503  	args.datatype = ap->datatype;
3504  
3505  	error = xfs_alloc_vextent(&args);
3506  	if (error)
3507  		return error;
3508  
3509  	if (args.fsbno != NULLFSBLOCK) {
3510  		xfs_bmap_process_allocated_extent(ap, &args, orig_offset,
3511  			orig_length);
3512  	} else {
3513  		ap->blkno = NULLFSBLOCK;
3514  		ap->length = 0;
3515  	}
3516  
3517  	return 0;
3518  }
3519  #else
3520  
3521  #define xfs_bmap_exact_minlen_extent_alloc(bma) (-EFSCORRUPTED)
3522  
3523  #endif
3524  
3525  STATIC int
3526  xfs_bmap_btalloc(
3527  	struct xfs_bmalloca	*ap)
3528  {
3529  	struct xfs_mount	*mp = ap->ip->i_mount;
3530  	struct xfs_alloc_arg	args = { .tp = ap->tp, .mp = mp };
3531  	xfs_alloctype_t		atype = 0;
3532  	xfs_agnumber_t		fb_agno;	/* ag number of ap->firstblock */
3533  	xfs_agnumber_t		ag;
3534  	xfs_fileoff_t		orig_offset;
3535  	xfs_extlen_t		orig_length;
3536  	xfs_extlen_t		blen;
3537  	xfs_extlen_t		nextminlen = 0;
3538  	int			nullfb; /* true if ap->firstblock isn't set */
3539  	int			isaligned;
3540  	int			tryagain;
3541  	int			error;
3542  	int			stripe_align;
3543  
3544  	ASSERT(ap->length);
3545  	orig_offset = ap->offset;
3546  	orig_length = ap->length;
3547  
3548  	stripe_align = xfs_bmap_compute_alignments(ap, &args);
3549  
3550  	nullfb = ap->tp->t_firstblock == NULLFSBLOCK;
3551  	fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp,
3552  							ap->tp->t_firstblock);
3553  	if (nullfb) {
3554  		if ((ap->datatype & XFS_ALLOC_USERDATA) &&
3555  		    xfs_inode_is_filestream(ap->ip)) {
3556  			ag = xfs_filestream_lookup_ag(ap->ip);
3557  			ag = (ag != NULLAGNUMBER) ? ag : 0;
3558  			ap->blkno = XFS_AGB_TO_FSB(mp, ag, 0);
3559  		} else {
3560  			ap->blkno = XFS_INO_TO_FSB(mp, ap->ip->i_ino);
3561  		}
3562  	} else
3563  		ap->blkno = ap->tp->t_firstblock;
3564  
3565  	xfs_bmap_adjacent(ap);
3566  
3567  	/*
3568  	 * If allowed, use ap->blkno; otherwise must use firstblock since
3569  	 * it's in the right allocation group.
3570  	 */
3571  	if (nullfb || XFS_FSB_TO_AGNO(mp, ap->blkno) == fb_agno)
3572  		;
3573  	else
3574  		ap->blkno = ap->tp->t_firstblock;
3575  	/*
3576  	 * Normal allocation, done through xfs_alloc_vextent.
3577  	 */
3578  	tryagain = isaligned = 0;
3579  	args.fsbno = ap->blkno;
3580  	args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
3581  
3582  	/* Trim the allocation back to the maximum an AG can fit. */
3583  	args.maxlen = min(ap->length, mp->m_ag_max_usable);
3584  	blen = 0;
3585  	if (nullfb) {
3586  		/*
3587  		 * Search for an allocation group with a single extent large
3588  		 * enough for the request.  If one isn't found, then adjust
3589  		 * the minimum allocation size to the largest space found.
3590  		 */
3591  		if ((ap->datatype & XFS_ALLOC_USERDATA) &&
3592  		    xfs_inode_is_filestream(ap->ip))
3593  			error = xfs_bmap_btalloc_filestreams(ap, &args, &blen);
3594  		else
3595  			error = xfs_bmap_btalloc_nullfb(ap, &args, &blen);
3596  		if (error)
3597  			return error;
3598  	} else if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
3599  		if (xfs_inode_is_filestream(ap->ip))
3600  			args.type = XFS_ALLOCTYPE_FIRST_AG;
3601  		else
3602  			args.type = XFS_ALLOCTYPE_START_BNO;
3603  		args.total = args.minlen = ap->minlen;
3604  	} else {
3605  		args.type = XFS_ALLOCTYPE_NEAR_BNO;
3606  		args.total = ap->total;
3607  		args.minlen = ap->minlen;
3608  	}
3609  
3610  	/*
3611  	 * If we are not low on available data blocks, and the underlying
3612  	 * logical volume manager is a stripe, and the file offset is zero then
3613  	 * try to allocate data blocks on stripe unit boundary. NOTE: ap->aeof
3614  	 * is only set if the allocation length is >= the stripe unit and the
3615  	 * allocation offset is at the end of file.
3616  	 */
3617  	if (!(ap->tp->t_flags & XFS_TRANS_LOWMODE) && ap->aeof) {
3618  		if (!ap->offset) {
3619  			args.alignment = stripe_align;
3620  			atype = args.type;
3621  			isaligned = 1;
3622  			/*
3623  			 * Adjust minlen to try and preserve alignment if we
3624  			 * can't guarantee an aligned maxlen extent.
3625  			 */
3626  			if (blen > args.alignment &&
3627  			    blen <= args.maxlen + args.alignment)
3628  				args.minlen = blen - args.alignment;
3629  			args.minalignslop = 0;
3630  		} else {
3631  			/*
3632  			 * First try an exact bno allocation.
3633  			 * If it fails then do a near or start bno
3634  			 * allocation with alignment turned on.
3635  			 */
3636  			atype = args.type;
3637  			tryagain = 1;
3638  			args.type = XFS_ALLOCTYPE_THIS_BNO;
3639  			args.alignment = 1;
3640  			/*
3641  			 * Compute the minlen+alignment for the
3642  			 * next case.  Set slop so that the value
3643  			 * of minlen+alignment+slop doesn't go up
3644  			 * between the calls.
3645  			 */
3646  			if (blen > stripe_align && blen <= args.maxlen)
3647  				nextminlen = blen - stripe_align;
3648  			else
3649  				nextminlen = args.minlen;
3650  			if (nextminlen + stripe_align > args.minlen + 1)
3651  				args.minalignslop =
3652  					nextminlen + stripe_align -
3653  					args.minlen - 1;
3654  			else
3655  				args.minalignslop = 0;
3656  		}
3657  	} else {
3658  		args.alignment = 1;
3659  		args.minalignslop = 0;
3660  	}
3661  	args.minleft = ap->minleft;
3662  	args.wasdel = ap->wasdel;
3663  	args.resv = XFS_AG_RESV_NONE;
3664  	args.datatype = ap->datatype;
3665  
3666  	error = xfs_alloc_vextent(&args);
3667  	if (error)
3668  		return error;
3669  
3670  	if (tryagain && args.fsbno == NULLFSBLOCK) {
3671  		/*
3672  		 * Exact allocation failed. Now try with alignment
3673  		 * turned on.
3674  		 */
3675  		args.type = atype;
3676  		args.fsbno = ap->blkno;
3677  		args.alignment = stripe_align;
3678  		args.minlen = nextminlen;
3679  		args.minalignslop = 0;
3680  		isaligned = 1;
3681  		if ((error = xfs_alloc_vextent(&args)))
3682  			return error;
3683  	}
3684  	if (isaligned && args.fsbno == NULLFSBLOCK) {
3685  		/*
3686  		 * allocation failed, so turn off alignment and
3687  		 * try again.
3688  		 */
3689  		args.type = atype;
3690  		args.fsbno = ap->blkno;
3691  		args.alignment = 0;
3692  		if ((error = xfs_alloc_vextent(&args)))
3693  			return error;
3694  	}
3695  	if (args.fsbno == NULLFSBLOCK && nullfb &&
3696  	    args.minlen > ap->minlen) {
3697  		args.minlen = ap->minlen;
3698  		args.type = XFS_ALLOCTYPE_START_BNO;
3699  		args.fsbno = ap->blkno;
3700  		if ((error = xfs_alloc_vextent(&args)))
3701  			return error;
3702  	}
3703  	if (args.fsbno == NULLFSBLOCK && nullfb) {
3704  		args.fsbno = 0;
3705  		args.type = XFS_ALLOCTYPE_FIRST_AG;
3706  		args.total = ap->minlen;
3707  		if ((error = xfs_alloc_vextent(&args)))
3708  			return error;
3709  		ap->tp->t_flags |= XFS_TRANS_LOWMODE;
3710  	}
3711  
3712  	if (args.fsbno != NULLFSBLOCK) {
3713  		xfs_bmap_process_allocated_extent(ap, &args, orig_offset,
3714  			orig_length);
3715  	} else {
3716  		ap->blkno = NULLFSBLOCK;
3717  		ap->length = 0;
3718  	}
3719  	return 0;
3720  }
3721  
3722  /* Trim extent to fit a logical block range. */
3723  void
3724  xfs_trim_extent(
3725  	struct xfs_bmbt_irec	*irec,
3726  	xfs_fileoff_t		bno,
3727  	xfs_filblks_t		len)
3728  {
3729  	xfs_fileoff_t		distance;
3730  	xfs_fileoff_t		end = bno + len;
3731  
3732  	if (irec->br_startoff + irec->br_blockcount <= bno ||
3733  	    irec->br_startoff >= end) {
3734  		irec->br_blockcount = 0;
3735  		return;
3736  	}
3737  
3738  	if (irec->br_startoff < bno) {
3739  		distance = bno - irec->br_startoff;
3740  		if (isnullstartblock(irec->br_startblock))
3741  			irec->br_startblock = DELAYSTARTBLOCK;
3742  		if (irec->br_startblock != DELAYSTARTBLOCK &&
3743  		    irec->br_startblock != HOLESTARTBLOCK)
3744  			irec->br_startblock += distance;
3745  		irec->br_startoff += distance;
3746  		irec->br_blockcount -= distance;
3747  	}
3748  
3749  	if (end < irec->br_startoff + irec->br_blockcount) {
3750  		distance = irec->br_startoff + irec->br_blockcount - end;
3751  		irec->br_blockcount -= distance;
3752  	}
3753  }
3754  
3755  /*
3756   * Trim the returned map to the required bounds
3757   */
3758  STATIC void
3759  xfs_bmapi_trim_map(
3760  	struct xfs_bmbt_irec	*mval,
3761  	struct xfs_bmbt_irec	*got,
3762  	xfs_fileoff_t		*bno,
3763  	xfs_filblks_t		len,
3764  	xfs_fileoff_t		obno,
3765  	xfs_fileoff_t		end,
3766  	int			n,
3767  	uint32_t		flags)
3768  {
3769  	if ((flags & XFS_BMAPI_ENTIRE) ||
3770  	    got->br_startoff + got->br_blockcount <= obno) {
3771  		*mval = *got;
3772  		if (isnullstartblock(got->br_startblock))
3773  			mval->br_startblock = DELAYSTARTBLOCK;
3774  		return;
3775  	}
3776  
3777  	if (obno > *bno)
3778  		*bno = obno;
3779  	ASSERT((*bno >= obno) || (n == 0));
3780  	ASSERT(*bno < end);
3781  	mval->br_startoff = *bno;
3782  	if (isnullstartblock(got->br_startblock))
3783  		mval->br_startblock = DELAYSTARTBLOCK;
3784  	else
3785  		mval->br_startblock = got->br_startblock +
3786  					(*bno - got->br_startoff);
3787  	/*
3788  	 * Return the minimum of what we got and what we asked for for
3789  	 * the length.  We can use the len variable here because it is
3790  	 * modified below and we could have been there before coming
3791  	 * here if the first part of the allocation didn't overlap what
3792  	 * was asked for.
3793  	 */
3794  	mval->br_blockcount = XFS_FILBLKS_MIN(end - *bno,
3795  			got->br_blockcount - (*bno - got->br_startoff));
3796  	mval->br_state = got->br_state;
3797  	ASSERT(mval->br_blockcount <= len);
3798  	return;
3799  }
3800  
3801  /*
3802   * Update and validate the extent map to return
3803   */
3804  STATIC void
3805  xfs_bmapi_update_map(
3806  	struct xfs_bmbt_irec	**map,
3807  	xfs_fileoff_t		*bno,
3808  	xfs_filblks_t		*len,
3809  	xfs_fileoff_t		obno,
3810  	xfs_fileoff_t		end,
3811  	int			*n,
3812  	uint32_t		flags)
3813  {
3814  	xfs_bmbt_irec_t	*mval = *map;
3815  
3816  	ASSERT((flags & XFS_BMAPI_ENTIRE) ||
3817  	       ((mval->br_startoff + mval->br_blockcount) <= end));
3818  	ASSERT((flags & XFS_BMAPI_ENTIRE) || (mval->br_blockcount <= *len) ||
3819  	       (mval->br_startoff < obno));
3820  
3821  	*bno = mval->br_startoff + mval->br_blockcount;
3822  	*len = end - *bno;
3823  	if (*n > 0 && mval->br_startoff == mval[-1].br_startoff) {
3824  		/* update previous map with new information */
3825  		ASSERT(mval->br_startblock == mval[-1].br_startblock);
3826  		ASSERT(mval->br_blockcount > mval[-1].br_blockcount);
3827  		ASSERT(mval->br_state == mval[-1].br_state);
3828  		mval[-1].br_blockcount = mval->br_blockcount;
3829  		mval[-1].br_state = mval->br_state;
3830  	} else if (*n > 0 && mval->br_startblock != DELAYSTARTBLOCK &&
3831  		   mval[-1].br_startblock != DELAYSTARTBLOCK &&
3832  		   mval[-1].br_startblock != HOLESTARTBLOCK &&
3833  		   mval->br_startblock == mval[-1].br_startblock +
3834  					  mval[-1].br_blockcount &&
3835  		   mval[-1].br_state == mval->br_state) {
3836  		ASSERT(mval->br_startoff ==
3837  		       mval[-1].br_startoff + mval[-1].br_blockcount);
3838  		mval[-1].br_blockcount += mval->br_blockcount;
3839  	} else if (*n > 0 &&
3840  		   mval->br_startblock == DELAYSTARTBLOCK &&
3841  		   mval[-1].br_startblock == DELAYSTARTBLOCK &&
3842  		   mval->br_startoff ==
3843  		   mval[-1].br_startoff + mval[-1].br_blockcount) {
3844  		mval[-1].br_blockcount += mval->br_blockcount;
3845  		mval[-1].br_state = mval->br_state;
3846  	} else if (!((*n == 0) &&
3847  		     ((mval->br_startoff + mval->br_blockcount) <=
3848  		      obno))) {
3849  		mval++;
3850  		(*n)++;
3851  	}
3852  	*map = mval;
3853  }
3854  
3855  /*
3856   * Map file blocks to filesystem blocks without allocation.
3857   */
3858  int
3859  xfs_bmapi_read(
3860  	struct xfs_inode	*ip,
3861  	xfs_fileoff_t		bno,
3862  	xfs_filblks_t		len,
3863  	struct xfs_bmbt_irec	*mval,
3864  	int			*nmap,
3865  	uint32_t		flags)
3866  {
3867  	struct xfs_mount	*mp = ip->i_mount;
3868  	int			whichfork = xfs_bmapi_whichfork(flags);
3869  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
3870  	struct xfs_bmbt_irec	got;
3871  	xfs_fileoff_t		obno;
3872  	xfs_fileoff_t		end;
3873  	struct xfs_iext_cursor	icur;
3874  	int			error;
3875  	bool			eof = false;
3876  	int			n = 0;
3877  
3878  	ASSERT(*nmap >= 1);
3879  	ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK | XFS_BMAPI_ENTIRE)));
3880  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED|XFS_ILOCK_EXCL));
3881  
3882  	if (WARN_ON_ONCE(!ifp))
3883  		return -EFSCORRUPTED;
3884  
3885  	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
3886  	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT))
3887  		return -EFSCORRUPTED;
3888  
3889  	if (xfs_is_shutdown(mp))
3890  		return -EIO;
3891  
3892  	XFS_STATS_INC(mp, xs_blk_mapr);
3893  
3894  	error = xfs_iread_extents(NULL, ip, whichfork);
3895  	if (error)
3896  		return error;
3897  
3898  	if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got))
3899  		eof = true;
3900  	end = bno + len;
3901  	obno = bno;
3902  
3903  	while (bno < end && n < *nmap) {
3904  		/* Reading past eof, act as though there's a hole up to end. */
3905  		if (eof)
3906  			got.br_startoff = end;
3907  		if (got.br_startoff > bno) {
3908  			/* Reading in a hole.  */
3909  			mval->br_startoff = bno;
3910  			mval->br_startblock = HOLESTARTBLOCK;
3911  			mval->br_blockcount =
3912  				XFS_FILBLKS_MIN(len, got.br_startoff - bno);
3913  			mval->br_state = XFS_EXT_NORM;
3914  			bno += mval->br_blockcount;
3915  			len -= mval->br_blockcount;
3916  			mval++;
3917  			n++;
3918  			continue;
3919  		}
3920  
3921  		/* set up the extent map to return. */
3922  		xfs_bmapi_trim_map(mval, &got, &bno, len, obno, end, n, flags);
3923  		xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
3924  
3925  		/* If we're done, stop now. */
3926  		if (bno >= end || n >= *nmap)
3927  			break;
3928  
3929  		/* Else go on to the next record. */
3930  		if (!xfs_iext_next_extent(ifp, &icur, &got))
3931  			eof = true;
3932  	}
3933  	*nmap = n;
3934  	return 0;
3935  }
3936  
3937  /*
3938   * Add a delayed allocation extent to an inode. Blocks are reserved from the
3939   * global pool and the extent inserted into the inode in-core extent tree.
3940   *
3941   * On entry, got refers to the first extent beyond the offset of the extent to
3942   * allocate or eof is specified if no such extent exists. On return, got refers
3943   * to the extent record that was inserted to the inode fork.
3944   *
3945   * Note that the allocated extent may have been merged with contiguous extents
3946   * during insertion into the inode fork. Thus, got does not reflect the current
3947   * state of the inode fork on return. If necessary, the caller can use lastx to
3948   * look up the updated record in the inode fork.
3949   */
3950  int
3951  xfs_bmapi_reserve_delalloc(
3952  	struct xfs_inode	*ip,
3953  	int			whichfork,
3954  	xfs_fileoff_t		off,
3955  	xfs_filblks_t		len,
3956  	xfs_filblks_t		prealloc,
3957  	struct xfs_bmbt_irec	*got,
3958  	struct xfs_iext_cursor	*icur,
3959  	int			eof)
3960  {
3961  	struct xfs_mount	*mp = ip->i_mount;
3962  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
3963  	xfs_extlen_t		alen;
3964  	xfs_extlen_t		indlen;
3965  	int			error;
3966  	xfs_fileoff_t		aoff = off;
3967  
3968  	/*
3969  	 * Cap the alloc length. Keep track of prealloc so we know whether to
3970  	 * tag the inode before we return.
3971  	 */
3972  	alen = XFS_FILBLKS_MIN(len + prealloc, XFS_MAX_BMBT_EXTLEN);
3973  	if (!eof)
3974  		alen = XFS_FILBLKS_MIN(alen, got->br_startoff - aoff);
3975  	if (prealloc && alen >= len)
3976  		prealloc = alen - len;
3977  
3978  	/* Figure out the extent size, adjust alen */
3979  	if (whichfork == XFS_COW_FORK) {
3980  		struct xfs_bmbt_irec	prev;
3981  		xfs_extlen_t		extsz = xfs_get_cowextsz_hint(ip);
3982  
3983  		if (!xfs_iext_peek_prev_extent(ifp, icur, &prev))
3984  			prev.br_startoff = NULLFILEOFF;
3985  
3986  		error = xfs_bmap_extsize_align(mp, got, &prev, extsz, 0, eof,
3987  					       1, 0, &aoff, &alen);
3988  		ASSERT(!error);
3989  	}
3990  
3991  	/*
3992  	 * Make a transaction-less quota reservation for delayed allocation
3993  	 * blocks.  This number gets adjusted later.  We return if we haven't
3994  	 * allocated blocks already inside this loop.
3995  	 */
3996  	error = xfs_quota_reserve_blkres(ip, alen);
3997  	if (error)
3998  		return error;
3999  
4000  	/*
4001  	 * Split changing sb for alen and indlen since they could be coming
4002  	 * from different places.
4003  	 */
4004  	indlen = (xfs_extlen_t)xfs_bmap_worst_indlen(ip, alen);
4005  	ASSERT(indlen > 0);
4006  
4007  	error = xfs_mod_fdblocks(mp, -((int64_t)alen), false);
4008  	if (error)
4009  		goto out_unreserve_quota;
4010  
4011  	error = xfs_mod_fdblocks(mp, -((int64_t)indlen), false);
4012  	if (error)
4013  		goto out_unreserve_blocks;
4014  
4015  
4016  	ip->i_delayed_blks += alen;
4017  	xfs_mod_delalloc(ip->i_mount, alen + indlen);
4018  
4019  	got->br_startoff = aoff;
4020  	got->br_startblock = nullstartblock(indlen);
4021  	got->br_blockcount = alen;
4022  	got->br_state = XFS_EXT_NORM;
4023  
4024  	xfs_bmap_add_extent_hole_delay(ip, whichfork, icur, got);
4025  
4026  	/*
4027  	 * Tag the inode if blocks were preallocated. Note that COW fork
4028  	 * preallocation can occur at the start or end of the extent, even when
4029  	 * prealloc == 0, so we must also check the aligned offset and length.
4030  	 */
4031  	if (whichfork == XFS_DATA_FORK && prealloc)
4032  		xfs_inode_set_eofblocks_tag(ip);
4033  	if (whichfork == XFS_COW_FORK && (prealloc || aoff < off || alen > len))
4034  		xfs_inode_set_cowblocks_tag(ip);
4035  
4036  	return 0;
4037  
4038  out_unreserve_blocks:
4039  	xfs_mod_fdblocks(mp, alen, false);
4040  out_unreserve_quota:
4041  	if (XFS_IS_QUOTA_ON(mp))
4042  		xfs_quota_unreserve_blkres(ip, alen);
4043  	return error;
4044  }
4045  
4046  static int
4047  xfs_bmap_alloc_userdata(
4048  	struct xfs_bmalloca	*bma)
4049  {
4050  	struct xfs_mount	*mp = bma->ip->i_mount;
4051  	int			whichfork = xfs_bmapi_whichfork(bma->flags);
4052  	int			error;
4053  
4054  	/*
4055  	 * Set the data type being allocated. For the data fork, the first data
4056  	 * in the file is treated differently to all other allocations. For the
4057  	 * attribute fork, we only need to ensure the allocated range is not on
4058  	 * the busy list.
4059  	 */
4060  	bma->datatype = XFS_ALLOC_NOBUSY;
4061  	if (whichfork == XFS_DATA_FORK) {
4062  		bma->datatype |= XFS_ALLOC_USERDATA;
4063  		if (bma->offset == 0)
4064  			bma->datatype |= XFS_ALLOC_INITIAL_USER_DATA;
4065  
4066  		if (mp->m_dalign && bma->length >= mp->m_dalign) {
4067  			error = xfs_bmap_isaeof(bma, whichfork);
4068  			if (error)
4069  				return error;
4070  		}
4071  
4072  		if (XFS_IS_REALTIME_INODE(bma->ip))
4073  			return xfs_bmap_rtalloc(bma);
4074  	}
4075  
4076  	if (unlikely(XFS_TEST_ERROR(false, mp,
4077  			XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT)))
4078  		return xfs_bmap_exact_minlen_extent_alloc(bma);
4079  
4080  	return xfs_bmap_btalloc(bma);
4081  }
4082  
4083  static int
4084  xfs_bmapi_allocate(
4085  	struct xfs_bmalloca	*bma)
4086  {
4087  	struct xfs_mount	*mp = bma->ip->i_mount;
4088  	int			whichfork = xfs_bmapi_whichfork(bma->flags);
4089  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(bma->ip, whichfork);
4090  	int			tmp_logflags = 0;
4091  	int			error;
4092  
4093  	ASSERT(bma->length > 0);
4094  
4095  	/*
4096  	 * For the wasdelay case, we could also just allocate the stuff asked
4097  	 * for in this bmap call but that wouldn't be as good.
4098  	 */
4099  	if (bma->wasdel) {
4100  		bma->length = (xfs_extlen_t)bma->got.br_blockcount;
4101  		bma->offset = bma->got.br_startoff;
4102  		if (!xfs_iext_peek_prev_extent(ifp, &bma->icur, &bma->prev))
4103  			bma->prev.br_startoff = NULLFILEOFF;
4104  	} else {
4105  		bma->length = XFS_FILBLKS_MIN(bma->length, XFS_MAX_BMBT_EXTLEN);
4106  		if (!bma->eof)
4107  			bma->length = XFS_FILBLKS_MIN(bma->length,
4108  					bma->got.br_startoff - bma->offset);
4109  	}
4110  
4111  	if (bma->flags & XFS_BMAPI_CONTIG)
4112  		bma->minlen = bma->length;
4113  	else
4114  		bma->minlen = 1;
4115  
4116  	if (bma->flags & XFS_BMAPI_METADATA) {
4117  		if (unlikely(XFS_TEST_ERROR(false, mp,
4118  				XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT)))
4119  			error = xfs_bmap_exact_minlen_extent_alloc(bma);
4120  		else
4121  			error = xfs_bmap_btalloc(bma);
4122  	} else {
4123  		error = xfs_bmap_alloc_userdata(bma);
4124  	}
4125  	if (error || bma->blkno == NULLFSBLOCK)
4126  		return error;
4127  
4128  	if (bma->flags & XFS_BMAPI_ZERO) {
4129  		error = xfs_zero_extent(bma->ip, bma->blkno, bma->length);
4130  		if (error)
4131  			return error;
4132  	}
4133  
4134  	if (ifp->if_format == XFS_DINODE_FMT_BTREE && !bma->cur)
4135  		bma->cur = xfs_bmbt_init_cursor(mp, bma->tp, bma->ip, whichfork);
4136  	/*
4137  	 * Bump the number of extents we've allocated
4138  	 * in this call.
4139  	 */
4140  	bma->nallocs++;
4141  
4142  	if (bma->cur)
4143  		bma->cur->bc_ino.flags =
4144  			bma->wasdel ? XFS_BTCUR_BMBT_WASDEL : 0;
4145  
4146  	bma->got.br_startoff = bma->offset;
4147  	bma->got.br_startblock = bma->blkno;
4148  	bma->got.br_blockcount = bma->length;
4149  	bma->got.br_state = XFS_EXT_NORM;
4150  
4151  	if (bma->flags & XFS_BMAPI_PREALLOC)
4152  		bma->got.br_state = XFS_EXT_UNWRITTEN;
4153  
4154  	if (bma->wasdel)
4155  		error = xfs_bmap_add_extent_delay_real(bma, whichfork);
4156  	else
4157  		error = xfs_bmap_add_extent_hole_real(bma->tp, bma->ip,
4158  				whichfork, &bma->icur, &bma->cur, &bma->got,
4159  				&bma->logflags, bma->flags);
4160  
4161  	bma->logflags |= tmp_logflags;
4162  	if (error)
4163  		return error;
4164  
4165  	/*
4166  	 * Update our extent pointer, given that xfs_bmap_add_extent_delay_real
4167  	 * or xfs_bmap_add_extent_hole_real might have merged it into one of
4168  	 * the neighbouring ones.
4169  	 */
4170  	xfs_iext_get_extent(ifp, &bma->icur, &bma->got);
4171  
4172  	ASSERT(bma->got.br_startoff <= bma->offset);
4173  	ASSERT(bma->got.br_startoff + bma->got.br_blockcount >=
4174  	       bma->offset + bma->length);
4175  	ASSERT(bma->got.br_state == XFS_EXT_NORM ||
4176  	       bma->got.br_state == XFS_EXT_UNWRITTEN);
4177  	return 0;
4178  }
4179  
4180  STATIC int
4181  xfs_bmapi_convert_unwritten(
4182  	struct xfs_bmalloca	*bma,
4183  	struct xfs_bmbt_irec	*mval,
4184  	xfs_filblks_t		len,
4185  	uint32_t		flags)
4186  {
4187  	int			whichfork = xfs_bmapi_whichfork(flags);
4188  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(bma->ip, whichfork);
4189  	int			tmp_logflags = 0;
4190  	int			error;
4191  
4192  	/* check if we need to do unwritten->real conversion */
4193  	if (mval->br_state == XFS_EXT_UNWRITTEN &&
4194  	    (flags & XFS_BMAPI_PREALLOC))
4195  		return 0;
4196  
4197  	/* check if we need to do real->unwritten conversion */
4198  	if (mval->br_state == XFS_EXT_NORM &&
4199  	    (flags & (XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT)) !=
4200  			(XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT))
4201  		return 0;
4202  
4203  	/*
4204  	 * Modify (by adding) the state flag, if writing.
4205  	 */
4206  	ASSERT(mval->br_blockcount <= len);
4207  	if (ifp->if_format == XFS_DINODE_FMT_BTREE && !bma->cur) {
4208  		bma->cur = xfs_bmbt_init_cursor(bma->ip->i_mount, bma->tp,
4209  					bma->ip, whichfork);
4210  	}
4211  	mval->br_state = (mval->br_state == XFS_EXT_UNWRITTEN)
4212  				? XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
4213  
4214  	/*
4215  	 * Before insertion into the bmbt, zero the range being converted
4216  	 * if required.
4217  	 */
4218  	if (flags & XFS_BMAPI_ZERO) {
4219  		error = xfs_zero_extent(bma->ip, mval->br_startblock,
4220  					mval->br_blockcount);
4221  		if (error)
4222  			return error;
4223  	}
4224  
4225  	error = xfs_bmap_add_extent_unwritten_real(bma->tp, bma->ip, whichfork,
4226  			&bma->icur, &bma->cur, mval, &tmp_logflags);
4227  	/*
4228  	 * Log the inode core unconditionally in the unwritten extent conversion
4229  	 * path because the conversion might not have done so (e.g., if the
4230  	 * extent count hasn't changed). We need to make sure the inode is dirty
4231  	 * in the transaction for the sake of fsync(), even if nothing has
4232  	 * changed, because fsync() will not force the log for this transaction
4233  	 * unless it sees the inode pinned.
4234  	 *
4235  	 * Note: If we're only converting cow fork extents, there aren't
4236  	 * any on-disk updates to make, so we don't need to log anything.
4237  	 */
4238  	if (whichfork != XFS_COW_FORK)
4239  		bma->logflags |= tmp_logflags | XFS_ILOG_CORE;
4240  	if (error)
4241  		return error;
4242  
4243  	/*
4244  	 * Update our extent pointer, given that
4245  	 * xfs_bmap_add_extent_unwritten_real might have merged it into one
4246  	 * of the neighbouring ones.
4247  	 */
4248  	xfs_iext_get_extent(ifp, &bma->icur, &bma->got);
4249  
4250  	/*
4251  	 * We may have combined previously unwritten space with written space,
4252  	 * so generate another request.
4253  	 */
4254  	if (mval->br_blockcount < len)
4255  		return -EAGAIN;
4256  	return 0;
4257  }
4258  
4259  static inline xfs_extlen_t
4260  xfs_bmapi_minleft(
4261  	struct xfs_trans	*tp,
4262  	struct xfs_inode	*ip,
4263  	int			fork)
4264  {
4265  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, fork);
4266  
4267  	if (tp && tp->t_firstblock != NULLFSBLOCK)
4268  		return 0;
4269  	if (ifp->if_format != XFS_DINODE_FMT_BTREE)
4270  		return 1;
4271  	return be16_to_cpu(ifp->if_broot->bb_level) + 1;
4272  }
4273  
4274  /*
4275   * Log whatever the flags say, even if error.  Otherwise we might miss detecting
4276   * a case where the data is changed, there's an error, and it's not logged so we
4277   * don't shutdown when we should.  Don't bother logging extents/btree changes if
4278   * we converted to the other format.
4279   */
4280  static void
4281  xfs_bmapi_finish(
4282  	struct xfs_bmalloca	*bma,
4283  	int			whichfork,
4284  	int			error)
4285  {
4286  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(bma->ip, whichfork);
4287  
4288  	if ((bma->logflags & xfs_ilog_fext(whichfork)) &&
4289  	    ifp->if_format != XFS_DINODE_FMT_EXTENTS)
4290  		bma->logflags &= ~xfs_ilog_fext(whichfork);
4291  	else if ((bma->logflags & xfs_ilog_fbroot(whichfork)) &&
4292  		 ifp->if_format != XFS_DINODE_FMT_BTREE)
4293  		bma->logflags &= ~xfs_ilog_fbroot(whichfork);
4294  
4295  	if (bma->logflags)
4296  		xfs_trans_log_inode(bma->tp, bma->ip, bma->logflags);
4297  	if (bma->cur)
4298  		xfs_btree_del_cursor(bma->cur, error);
4299  }
4300  
4301  /*
4302   * Map file blocks to filesystem blocks, and allocate blocks or convert the
4303   * extent state if necessary.  Details behaviour is controlled by the flags
4304   * parameter.  Only allocates blocks from a single allocation group, to avoid
4305   * locking problems.
4306   */
4307  int
4308  xfs_bmapi_write(
4309  	struct xfs_trans	*tp,		/* transaction pointer */
4310  	struct xfs_inode	*ip,		/* incore inode */
4311  	xfs_fileoff_t		bno,		/* starting file offs. mapped */
4312  	xfs_filblks_t		len,		/* length to map in file */
4313  	uint32_t		flags,		/* XFS_BMAPI_... */
4314  	xfs_extlen_t		total,		/* total blocks needed */
4315  	struct xfs_bmbt_irec	*mval,		/* output: map values */
4316  	int			*nmap)		/* i/o: mval size/count */
4317  {
4318  	struct xfs_bmalloca	bma = {
4319  		.tp		= tp,
4320  		.ip		= ip,
4321  		.total		= total,
4322  	};
4323  	struct xfs_mount	*mp = ip->i_mount;
4324  	int			whichfork = xfs_bmapi_whichfork(flags);
4325  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
4326  	xfs_fileoff_t		end;		/* end of mapped file region */
4327  	bool			eof = false;	/* after the end of extents */
4328  	int			error;		/* error return */
4329  	int			n;		/* current extent index */
4330  	xfs_fileoff_t		obno;		/* old block number (offset) */
4331  
4332  #ifdef DEBUG
4333  	xfs_fileoff_t		orig_bno;	/* original block number value */
4334  	int			orig_flags;	/* original flags arg value */
4335  	xfs_filblks_t		orig_len;	/* original value of len arg */
4336  	struct xfs_bmbt_irec	*orig_mval;	/* original value of mval */
4337  	int			orig_nmap;	/* original value of *nmap */
4338  
4339  	orig_bno = bno;
4340  	orig_len = len;
4341  	orig_flags = flags;
4342  	orig_mval = mval;
4343  	orig_nmap = *nmap;
4344  #endif
4345  
4346  	ASSERT(*nmap >= 1);
4347  	ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
4348  	ASSERT(tp != NULL);
4349  	ASSERT(len > 0);
4350  	ASSERT(ifp->if_format != XFS_DINODE_FMT_LOCAL);
4351  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
4352  	ASSERT(!(flags & XFS_BMAPI_REMAP));
4353  
4354  	/* zeroing is for currently only for data extents, not metadata */
4355  	ASSERT((flags & (XFS_BMAPI_METADATA | XFS_BMAPI_ZERO)) !=
4356  			(XFS_BMAPI_METADATA | XFS_BMAPI_ZERO));
4357  	/*
4358  	 * we can allocate unwritten extents or pre-zero allocated blocks,
4359  	 * but it makes no sense to do both at once. This would result in
4360  	 * zeroing the unwritten extent twice, but it still being an
4361  	 * unwritten extent....
4362  	 */
4363  	ASSERT((flags & (XFS_BMAPI_PREALLOC | XFS_BMAPI_ZERO)) !=
4364  			(XFS_BMAPI_PREALLOC | XFS_BMAPI_ZERO));
4365  
4366  	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
4367  	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
4368  		return -EFSCORRUPTED;
4369  	}
4370  
4371  	if (xfs_is_shutdown(mp))
4372  		return -EIO;
4373  
4374  	XFS_STATS_INC(mp, xs_blk_mapw);
4375  
4376  	error = xfs_iread_extents(tp, ip, whichfork);
4377  	if (error)
4378  		goto error0;
4379  
4380  	if (!xfs_iext_lookup_extent(ip, ifp, bno, &bma.icur, &bma.got))
4381  		eof = true;
4382  	if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
4383  		bma.prev.br_startoff = NULLFILEOFF;
4384  	bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
4385  
4386  	n = 0;
4387  	end = bno + len;
4388  	obno = bno;
4389  	while (bno < end && n < *nmap) {
4390  		bool			need_alloc = false, wasdelay = false;
4391  
4392  		/* in hole or beyond EOF? */
4393  		if (eof || bma.got.br_startoff > bno) {
4394  			/*
4395  			 * CoW fork conversions should /never/ hit EOF or
4396  			 * holes.  There should always be something for us
4397  			 * to work on.
4398  			 */
4399  			ASSERT(!((flags & XFS_BMAPI_CONVERT) &&
4400  			         (flags & XFS_BMAPI_COWFORK)));
4401  
4402  			need_alloc = true;
4403  		} else if (isnullstartblock(bma.got.br_startblock)) {
4404  			wasdelay = true;
4405  		}
4406  
4407  		/*
4408  		 * First, deal with the hole before the allocated space
4409  		 * that we found, if any.
4410  		 */
4411  		if (need_alloc || wasdelay) {
4412  			bma.eof = eof;
4413  			bma.conv = !!(flags & XFS_BMAPI_CONVERT);
4414  			bma.wasdel = wasdelay;
4415  			bma.offset = bno;
4416  			bma.flags = flags;
4417  
4418  			/*
4419  			 * There's a 32/64 bit type mismatch between the
4420  			 * allocation length request (which can be 64 bits in
4421  			 * length) and the bma length request, which is
4422  			 * xfs_extlen_t and therefore 32 bits. Hence we have to
4423  			 * check for 32-bit overflows and handle them here.
4424  			 */
4425  			if (len > (xfs_filblks_t)XFS_MAX_BMBT_EXTLEN)
4426  				bma.length = XFS_MAX_BMBT_EXTLEN;
4427  			else
4428  				bma.length = len;
4429  
4430  			ASSERT(len > 0);
4431  			ASSERT(bma.length > 0);
4432  			error = xfs_bmapi_allocate(&bma);
4433  			if (error)
4434  				goto error0;
4435  			if (bma.blkno == NULLFSBLOCK)
4436  				break;
4437  
4438  			/*
4439  			 * If this is a CoW allocation, record the data in
4440  			 * the refcount btree for orphan recovery.
4441  			 */
4442  			if (whichfork == XFS_COW_FORK)
4443  				xfs_refcount_alloc_cow_extent(tp, bma.blkno,
4444  						bma.length);
4445  		}
4446  
4447  		/* Deal with the allocated space we found.  */
4448  		xfs_bmapi_trim_map(mval, &bma.got, &bno, len, obno,
4449  							end, n, flags);
4450  
4451  		/* Execute unwritten extent conversion if necessary */
4452  		error = xfs_bmapi_convert_unwritten(&bma, mval, len, flags);
4453  		if (error == -EAGAIN)
4454  			continue;
4455  		if (error)
4456  			goto error0;
4457  
4458  		/* update the extent map to return */
4459  		xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
4460  
4461  		/*
4462  		 * If we're done, stop now.  Stop when we've allocated
4463  		 * XFS_BMAP_MAX_NMAP extents no matter what.  Otherwise
4464  		 * the transaction may get too big.
4465  		 */
4466  		if (bno >= end || n >= *nmap || bma.nallocs >= *nmap)
4467  			break;
4468  
4469  		/* Else go on to the next record. */
4470  		bma.prev = bma.got;
4471  		if (!xfs_iext_next_extent(ifp, &bma.icur, &bma.got))
4472  			eof = true;
4473  	}
4474  	*nmap = n;
4475  
4476  	error = xfs_bmap_btree_to_extents(tp, ip, bma.cur, &bma.logflags,
4477  			whichfork);
4478  	if (error)
4479  		goto error0;
4480  
4481  	ASSERT(ifp->if_format != XFS_DINODE_FMT_BTREE ||
4482  	       ifp->if_nextents > XFS_IFORK_MAXEXT(ip, whichfork));
4483  	xfs_bmapi_finish(&bma, whichfork, 0);
4484  	xfs_bmap_validate_ret(orig_bno, orig_len, orig_flags, orig_mval,
4485  		orig_nmap, *nmap);
4486  	return 0;
4487  error0:
4488  	xfs_bmapi_finish(&bma, whichfork, error);
4489  	return error;
4490  }
4491  
4492  /*
4493   * Convert an existing delalloc extent to real blocks based on file offset. This
4494   * attempts to allocate the entire delalloc extent and may require multiple
4495   * invocations to allocate the target offset if a large enough physical extent
4496   * is not available.
4497   */
4498  int
4499  xfs_bmapi_convert_delalloc(
4500  	struct xfs_inode	*ip,
4501  	int			whichfork,
4502  	xfs_off_t		offset,
4503  	struct iomap		*iomap,
4504  	unsigned int		*seq)
4505  {
4506  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
4507  	struct xfs_mount	*mp = ip->i_mount;
4508  	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
4509  	struct xfs_bmalloca	bma = { NULL };
4510  	uint16_t		flags = 0;
4511  	struct xfs_trans	*tp;
4512  	int			error;
4513  
4514  	if (whichfork == XFS_COW_FORK)
4515  		flags |= IOMAP_F_SHARED;
4516  
4517  	/*
4518  	 * Space for the extent and indirect blocks was reserved when the
4519  	 * delalloc extent was created so there's no need to do so here.
4520  	 */
4521  	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0,
4522  				XFS_TRANS_RESERVE, &tp);
4523  	if (error)
4524  		return error;
4525  
4526  	xfs_ilock(ip, XFS_ILOCK_EXCL);
4527  	xfs_trans_ijoin(tp, ip, 0);
4528  
4529  	error = xfs_iext_count_may_overflow(ip, whichfork,
4530  			XFS_IEXT_ADD_NOSPLIT_CNT);
4531  	if (error == -EFBIG)
4532  		error = xfs_iext_count_upgrade(tp, ip,
4533  				XFS_IEXT_ADD_NOSPLIT_CNT);
4534  	if (error)
4535  		goto out_trans_cancel;
4536  
4537  	if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &bma.icur, &bma.got) ||
4538  	    bma.got.br_startoff > offset_fsb) {
4539  		/*
4540  		 * No extent found in the range we are trying to convert.  This
4541  		 * should only happen for the COW fork, where another thread
4542  		 * might have moved the extent to the data fork in the meantime.
4543  		 */
4544  		WARN_ON_ONCE(whichfork != XFS_COW_FORK);
4545  		error = -EAGAIN;
4546  		goto out_trans_cancel;
4547  	}
4548  
4549  	/*
4550  	 * If we find a real extent here we raced with another thread converting
4551  	 * the extent.  Just return the real extent at this offset.
4552  	 */
4553  	if (!isnullstartblock(bma.got.br_startblock)) {
4554  		xfs_bmbt_to_iomap(ip, iomap, &bma.got, 0, flags);
4555  		*seq = READ_ONCE(ifp->if_seq);
4556  		goto out_trans_cancel;
4557  	}
4558  
4559  	bma.tp = tp;
4560  	bma.ip = ip;
4561  	bma.wasdel = true;
4562  	bma.offset = bma.got.br_startoff;
4563  	bma.length = max_t(xfs_filblks_t, bma.got.br_blockcount,
4564  			XFS_MAX_BMBT_EXTLEN);
4565  	bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
4566  
4567  	/*
4568  	 * When we're converting the delalloc reservations backing dirty pages
4569  	 * in the page cache, we must be careful about how we create the new
4570  	 * extents:
4571  	 *
4572  	 * New CoW fork extents are created unwritten, turned into real extents
4573  	 * when we're about to write the data to disk, and mapped into the data
4574  	 * fork after the write finishes.  End of story.
4575  	 *
4576  	 * New data fork extents must be mapped in as unwritten and converted
4577  	 * to real extents after the write succeeds to avoid exposing stale
4578  	 * disk contents if we crash.
4579  	 */
4580  	bma.flags = XFS_BMAPI_PREALLOC;
4581  	if (whichfork == XFS_COW_FORK)
4582  		bma.flags |= XFS_BMAPI_COWFORK;
4583  
4584  	if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
4585  		bma.prev.br_startoff = NULLFILEOFF;
4586  
4587  	error = xfs_bmapi_allocate(&bma);
4588  	if (error)
4589  		goto out_finish;
4590  
4591  	error = -ENOSPC;
4592  	if (WARN_ON_ONCE(bma.blkno == NULLFSBLOCK))
4593  		goto out_finish;
4594  	error = -EFSCORRUPTED;
4595  	if (WARN_ON_ONCE(!xfs_valid_startblock(ip, bma.got.br_startblock)))
4596  		goto out_finish;
4597  
4598  	XFS_STATS_ADD(mp, xs_xstrat_bytes, XFS_FSB_TO_B(mp, bma.length));
4599  	XFS_STATS_INC(mp, xs_xstrat_quick);
4600  
4601  	ASSERT(!isnullstartblock(bma.got.br_startblock));
4602  	xfs_bmbt_to_iomap(ip, iomap, &bma.got, 0, flags);
4603  	*seq = READ_ONCE(ifp->if_seq);
4604  
4605  	if (whichfork == XFS_COW_FORK)
4606  		xfs_refcount_alloc_cow_extent(tp, bma.blkno, bma.length);
4607  
4608  	error = xfs_bmap_btree_to_extents(tp, ip, bma.cur, &bma.logflags,
4609  			whichfork);
4610  	if (error)
4611  		goto out_finish;
4612  
4613  	xfs_bmapi_finish(&bma, whichfork, 0);
4614  	error = xfs_trans_commit(tp);
4615  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
4616  	return error;
4617  
4618  out_finish:
4619  	xfs_bmapi_finish(&bma, whichfork, error);
4620  out_trans_cancel:
4621  	xfs_trans_cancel(tp);
4622  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
4623  	return error;
4624  }
4625  
4626  int
4627  xfs_bmapi_remap(
4628  	struct xfs_trans	*tp,
4629  	struct xfs_inode	*ip,
4630  	xfs_fileoff_t		bno,
4631  	xfs_filblks_t		len,
4632  	xfs_fsblock_t		startblock,
4633  	uint32_t		flags)
4634  {
4635  	struct xfs_mount	*mp = ip->i_mount;
4636  	struct xfs_ifork	*ifp;
4637  	struct xfs_btree_cur	*cur = NULL;
4638  	struct xfs_bmbt_irec	got;
4639  	struct xfs_iext_cursor	icur;
4640  	int			whichfork = xfs_bmapi_whichfork(flags);
4641  	int			logflags = 0, error;
4642  
4643  	ifp = XFS_IFORK_PTR(ip, whichfork);
4644  	ASSERT(len > 0);
4645  	ASSERT(len <= (xfs_filblks_t)XFS_MAX_BMBT_EXTLEN);
4646  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
4647  	ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC |
4648  			   XFS_BMAPI_NORMAP)));
4649  	ASSERT((flags & (XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC)) !=
4650  			(XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC));
4651  
4652  	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
4653  	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
4654  		return -EFSCORRUPTED;
4655  	}
4656  
4657  	if (xfs_is_shutdown(mp))
4658  		return -EIO;
4659  
4660  	error = xfs_iread_extents(tp, ip, whichfork);
4661  	if (error)
4662  		return error;
4663  
4664  	if (xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
4665  		/* make sure we only reflink into a hole. */
4666  		ASSERT(got.br_startoff > bno);
4667  		ASSERT(got.br_startoff - bno >= len);
4668  	}
4669  
4670  	ip->i_nblocks += len;
4671  	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
4672  
4673  	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
4674  		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
4675  		cur->bc_ino.flags = 0;
4676  	}
4677  
4678  	got.br_startoff = bno;
4679  	got.br_startblock = startblock;
4680  	got.br_blockcount = len;
4681  	if (flags & XFS_BMAPI_PREALLOC)
4682  		got.br_state = XFS_EXT_UNWRITTEN;
4683  	else
4684  		got.br_state = XFS_EXT_NORM;
4685  
4686  	error = xfs_bmap_add_extent_hole_real(tp, ip, whichfork, &icur,
4687  			&cur, &got, &logflags, flags);
4688  	if (error)
4689  		goto error0;
4690  
4691  	error = xfs_bmap_btree_to_extents(tp, ip, cur, &logflags, whichfork);
4692  
4693  error0:
4694  	if (ip->i_df.if_format != XFS_DINODE_FMT_EXTENTS)
4695  		logflags &= ~XFS_ILOG_DEXT;
4696  	else if (ip->i_df.if_format != XFS_DINODE_FMT_BTREE)
4697  		logflags &= ~XFS_ILOG_DBROOT;
4698  
4699  	if (logflags)
4700  		xfs_trans_log_inode(tp, ip, logflags);
4701  	if (cur)
4702  		xfs_btree_del_cursor(cur, error);
4703  	return error;
4704  }
4705  
4706  /*
4707   * When a delalloc extent is split (e.g., due to a hole punch), the original
4708   * indlen reservation must be shared across the two new extents that are left
4709   * behind.
4710   *
4711   * Given the original reservation and the worst case indlen for the two new
4712   * extents (as calculated by xfs_bmap_worst_indlen()), split the original
4713   * reservation fairly across the two new extents. If necessary, steal available
4714   * blocks from a deleted extent to make up a reservation deficiency (e.g., if
4715   * ores == 1). The number of stolen blocks is returned. The availability and
4716   * subsequent accounting of stolen blocks is the responsibility of the caller.
4717   */
4718  static xfs_filblks_t
4719  xfs_bmap_split_indlen(
4720  	xfs_filblks_t			ores,		/* original res. */
4721  	xfs_filblks_t			*indlen1,	/* ext1 worst indlen */
4722  	xfs_filblks_t			*indlen2,	/* ext2 worst indlen */
4723  	xfs_filblks_t			avail)		/* stealable blocks */
4724  {
4725  	xfs_filblks_t			len1 = *indlen1;
4726  	xfs_filblks_t			len2 = *indlen2;
4727  	xfs_filblks_t			nres = len1 + len2; /* new total res. */
4728  	xfs_filblks_t			stolen = 0;
4729  	xfs_filblks_t			resfactor;
4730  
4731  	/*
4732  	 * Steal as many blocks as we can to try and satisfy the worst case
4733  	 * indlen for both new extents.
4734  	 */
4735  	if (ores < nres && avail)
4736  		stolen = XFS_FILBLKS_MIN(nres - ores, avail);
4737  	ores += stolen;
4738  
4739  	 /* nothing else to do if we've satisfied the new reservation */
4740  	if (ores >= nres)
4741  		return stolen;
4742  
4743  	/*
4744  	 * We can't meet the total required reservation for the two extents.
4745  	 * Calculate the percent of the overall shortage between both extents
4746  	 * and apply this percentage to each of the requested indlen values.
4747  	 * This distributes the shortage fairly and reduces the chances that one
4748  	 * of the two extents is left with nothing when extents are repeatedly
4749  	 * split.
4750  	 */
4751  	resfactor = (ores * 100);
4752  	do_div(resfactor, nres);
4753  	len1 *= resfactor;
4754  	do_div(len1, 100);
4755  	len2 *= resfactor;
4756  	do_div(len2, 100);
4757  	ASSERT(len1 + len2 <= ores);
4758  	ASSERT(len1 < *indlen1 && len2 < *indlen2);
4759  
4760  	/*
4761  	 * Hand out the remainder to each extent. If one of the two reservations
4762  	 * is zero, we want to make sure that one gets a block first. The loop
4763  	 * below starts with len1, so hand len2 a block right off the bat if it
4764  	 * is zero.
4765  	 */
4766  	ores -= (len1 + len2);
4767  	ASSERT((*indlen1 - len1) + (*indlen2 - len2) >= ores);
4768  	if (ores && !len2 && *indlen2) {
4769  		len2++;
4770  		ores--;
4771  	}
4772  	while (ores) {
4773  		if (len1 < *indlen1) {
4774  			len1++;
4775  			ores--;
4776  		}
4777  		if (!ores)
4778  			break;
4779  		if (len2 < *indlen2) {
4780  			len2++;
4781  			ores--;
4782  		}
4783  	}
4784  
4785  	*indlen1 = len1;
4786  	*indlen2 = len2;
4787  
4788  	return stolen;
4789  }
4790  
4791  int
4792  xfs_bmap_del_extent_delay(
4793  	struct xfs_inode	*ip,
4794  	int			whichfork,
4795  	struct xfs_iext_cursor	*icur,
4796  	struct xfs_bmbt_irec	*got,
4797  	struct xfs_bmbt_irec	*del)
4798  {
4799  	struct xfs_mount	*mp = ip->i_mount;
4800  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
4801  	struct xfs_bmbt_irec	new;
4802  	int64_t			da_old, da_new, da_diff = 0;
4803  	xfs_fileoff_t		del_endoff, got_endoff;
4804  	xfs_filblks_t		got_indlen, new_indlen, stolen;
4805  	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
4806  	int			error = 0;
4807  	bool			isrt;
4808  
4809  	XFS_STATS_INC(mp, xs_del_exlist);
4810  
4811  	isrt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip);
4812  	del_endoff = del->br_startoff + del->br_blockcount;
4813  	got_endoff = got->br_startoff + got->br_blockcount;
4814  	da_old = startblockval(got->br_startblock);
4815  	da_new = 0;
4816  
4817  	ASSERT(del->br_blockcount > 0);
4818  	ASSERT(got->br_startoff <= del->br_startoff);
4819  	ASSERT(got_endoff >= del_endoff);
4820  
4821  	if (isrt) {
4822  		uint64_t rtexts = XFS_FSB_TO_B(mp, del->br_blockcount);
4823  
4824  		do_div(rtexts, mp->m_sb.sb_rextsize);
4825  		xfs_mod_frextents(mp, rtexts);
4826  	}
4827  
4828  	/*
4829  	 * Update the inode delalloc counter now and wait to update the
4830  	 * sb counters as we might have to borrow some blocks for the
4831  	 * indirect block accounting.
4832  	 */
4833  	ASSERT(!isrt);
4834  	error = xfs_quota_unreserve_blkres(ip, del->br_blockcount);
4835  	if (error)
4836  		return error;
4837  	ip->i_delayed_blks -= del->br_blockcount;
4838  
4839  	if (got->br_startoff == del->br_startoff)
4840  		state |= BMAP_LEFT_FILLING;
4841  	if (got_endoff == del_endoff)
4842  		state |= BMAP_RIGHT_FILLING;
4843  
4844  	switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
4845  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
4846  		/*
4847  		 * Matches the whole extent.  Delete the entry.
4848  		 */
4849  		xfs_iext_remove(ip, icur, state);
4850  		xfs_iext_prev(ifp, icur);
4851  		break;
4852  	case BMAP_LEFT_FILLING:
4853  		/*
4854  		 * Deleting the first part of the extent.
4855  		 */
4856  		got->br_startoff = del_endoff;
4857  		got->br_blockcount -= del->br_blockcount;
4858  		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip,
4859  				got->br_blockcount), da_old);
4860  		got->br_startblock = nullstartblock((int)da_new);
4861  		xfs_iext_update_extent(ip, state, icur, got);
4862  		break;
4863  	case BMAP_RIGHT_FILLING:
4864  		/*
4865  		 * Deleting the last part of the extent.
4866  		 */
4867  		got->br_blockcount = got->br_blockcount - del->br_blockcount;
4868  		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip,
4869  				got->br_blockcount), da_old);
4870  		got->br_startblock = nullstartblock((int)da_new);
4871  		xfs_iext_update_extent(ip, state, icur, got);
4872  		break;
4873  	case 0:
4874  		/*
4875  		 * Deleting the middle of the extent.
4876  		 *
4877  		 * Distribute the original indlen reservation across the two new
4878  		 * extents.  Steal blocks from the deleted extent if necessary.
4879  		 * Stealing blocks simply fudges the fdblocks accounting below.
4880  		 * Warn if either of the new indlen reservations is zero as this
4881  		 * can lead to delalloc problems.
4882  		 */
4883  		got->br_blockcount = del->br_startoff - got->br_startoff;
4884  		got_indlen = xfs_bmap_worst_indlen(ip, got->br_blockcount);
4885  
4886  		new.br_blockcount = got_endoff - del_endoff;
4887  		new_indlen = xfs_bmap_worst_indlen(ip, new.br_blockcount);
4888  
4889  		WARN_ON_ONCE(!got_indlen || !new_indlen);
4890  		stolen = xfs_bmap_split_indlen(da_old, &got_indlen, &new_indlen,
4891  						       del->br_blockcount);
4892  
4893  		got->br_startblock = nullstartblock((int)got_indlen);
4894  
4895  		new.br_startoff = del_endoff;
4896  		new.br_state = got->br_state;
4897  		new.br_startblock = nullstartblock((int)new_indlen);
4898  
4899  		xfs_iext_update_extent(ip, state, icur, got);
4900  		xfs_iext_next(ifp, icur);
4901  		xfs_iext_insert(ip, icur, &new, state);
4902  
4903  		da_new = got_indlen + new_indlen - stolen;
4904  		del->br_blockcount -= stolen;
4905  		break;
4906  	}
4907  
4908  	ASSERT(da_old >= da_new);
4909  	da_diff = da_old - da_new;
4910  	if (!isrt)
4911  		da_diff += del->br_blockcount;
4912  	if (da_diff) {
4913  		xfs_mod_fdblocks(mp, da_diff, false);
4914  		xfs_mod_delalloc(mp, -da_diff);
4915  	}
4916  	return error;
4917  }
4918  
4919  void
4920  xfs_bmap_del_extent_cow(
4921  	struct xfs_inode	*ip,
4922  	struct xfs_iext_cursor	*icur,
4923  	struct xfs_bmbt_irec	*got,
4924  	struct xfs_bmbt_irec	*del)
4925  {
4926  	struct xfs_mount	*mp = ip->i_mount;
4927  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
4928  	struct xfs_bmbt_irec	new;
4929  	xfs_fileoff_t		del_endoff, got_endoff;
4930  	uint32_t		state = BMAP_COWFORK;
4931  
4932  	XFS_STATS_INC(mp, xs_del_exlist);
4933  
4934  	del_endoff = del->br_startoff + del->br_blockcount;
4935  	got_endoff = got->br_startoff + got->br_blockcount;
4936  
4937  	ASSERT(del->br_blockcount > 0);
4938  	ASSERT(got->br_startoff <= del->br_startoff);
4939  	ASSERT(got_endoff >= del_endoff);
4940  	ASSERT(!isnullstartblock(got->br_startblock));
4941  
4942  	if (got->br_startoff == del->br_startoff)
4943  		state |= BMAP_LEFT_FILLING;
4944  	if (got_endoff == del_endoff)
4945  		state |= BMAP_RIGHT_FILLING;
4946  
4947  	switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
4948  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
4949  		/*
4950  		 * Matches the whole extent.  Delete the entry.
4951  		 */
4952  		xfs_iext_remove(ip, icur, state);
4953  		xfs_iext_prev(ifp, icur);
4954  		break;
4955  	case BMAP_LEFT_FILLING:
4956  		/*
4957  		 * Deleting the first part of the extent.
4958  		 */
4959  		got->br_startoff = del_endoff;
4960  		got->br_blockcount -= del->br_blockcount;
4961  		got->br_startblock = del->br_startblock + del->br_blockcount;
4962  		xfs_iext_update_extent(ip, state, icur, got);
4963  		break;
4964  	case BMAP_RIGHT_FILLING:
4965  		/*
4966  		 * Deleting the last part of the extent.
4967  		 */
4968  		got->br_blockcount -= del->br_blockcount;
4969  		xfs_iext_update_extent(ip, state, icur, got);
4970  		break;
4971  	case 0:
4972  		/*
4973  		 * Deleting the middle of the extent.
4974  		 */
4975  		got->br_blockcount = del->br_startoff - got->br_startoff;
4976  
4977  		new.br_startoff = del_endoff;
4978  		new.br_blockcount = got_endoff - del_endoff;
4979  		new.br_state = got->br_state;
4980  		new.br_startblock = del->br_startblock + del->br_blockcount;
4981  
4982  		xfs_iext_update_extent(ip, state, icur, got);
4983  		xfs_iext_next(ifp, icur);
4984  		xfs_iext_insert(ip, icur, &new, state);
4985  		break;
4986  	}
4987  	ip->i_delayed_blks -= del->br_blockcount;
4988  }
4989  
4990  /*
4991   * Called by xfs_bmapi to update file extent records and the btree
4992   * after removing space.
4993   */
4994  STATIC int				/* error */
4995  xfs_bmap_del_extent_real(
4996  	xfs_inode_t		*ip,	/* incore inode pointer */
4997  	xfs_trans_t		*tp,	/* current transaction pointer */
4998  	struct xfs_iext_cursor	*icur,
4999  	struct xfs_btree_cur	*cur,	/* if null, not a btree */
5000  	xfs_bmbt_irec_t		*del,	/* data to remove from extents */
5001  	int			*logflagsp, /* inode logging flags */
5002  	int			whichfork, /* data or attr fork */
5003  	uint32_t		bflags)	/* bmapi flags */
5004  {
5005  	xfs_fsblock_t		del_endblock=0;	/* first block past del */
5006  	xfs_fileoff_t		del_endoff;	/* first offset past del */
5007  	int			do_fx;	/* free extent at end of routine */
5008  	int			error;	/* error return value */
5009  	int			flags = 0;/* inode logging flags */
5010  	struct xfs_bmbt_irec	got;	/* current extent entry */
5011  	xfs_fileoff_t		got_endoff;	/* first offset past got */
5012  	int			i;	/* temp state */
5013  	struct xfs_ifork	*ifp;	/* inode fork pointer */
5014  	xfs_mount_t		*mp;	/* mount structure */
5015  	xfs_filblks_t		nblks;	/* quota/sb block count */
5016  	xfs_bmbt_irec_t		new;	/* new record to be inserted */
5017  	/* REFERENCED */
5018  	uint			qfield;	/* quota field to update */
5019  	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
5020  	struct xfs_bmbt_irec	old;
5021  
5022  	mp = ip->i_mount;
5023  	XFS_STATS_INC(mp, xs_del_exlist);
5024  
5025  	ifp = XFS_IFORK_PTR(ip, whichfork);
5026  	ASSERT(del->br_blockcount > 0);
5027  	xfs_iext_get_extent(ifp, icur, &got);
5028  	ASSERT(got.br_startoff <= del->br_startoff);
5029  	del_endoff = del->br_startoff + del->br_blockcount;
5030  	got_endoff = got.br_startoff + got.br_blockcount;
5031  	ASSERT(got_endoff >= del_endoff);
5032  	ASSERT(!isnullstartblock(got.br_startblock));
5033  	qfield = 0;
5034  	error = 0;
5035  
5036  	/*
5037  	 * If it's the case where the directory code is running with no block
5038  	 * reservation, and the deleted block is in the middle of its extent,
5039  	 * and the resulting insert of an extent would cause transformation to
5040  	 * btree format, then reject it.  The calling code will then swap blocks
5041  	 * around instead.  We have to do this now, rather than waiting for the
5042  	 * conversion to btree format, since the transaction will be dirty then.
5043  	 */
5044  	if (tp->t_blk_res == 0 &&
5045  	    ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
5046  	    ifp->if_nextents >= XFS_IFORK_MAXEXT(ip, whichfork) &&
5047  	    del->br_startoff > got.br_startoff && del_endoff < got_endoff)
5048  		return -ENOSPC;
5049  
5050  	flags = XFS_ILOG_CORE;
5051  	if (whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip)) {
5052  		xfs_filblks_t	len;
5053  		xfs_extlen_t	mod;
5054  
5055  		len = div_u64_rem(del->br_blockcount, mp->m_sb.sb_rextsize,
5056  				  &mod);
5057  		ASSERT(mod == 0);
5058  
5059  		if (!(bflags & XFS_BMAPI_REMAP)) {
5060  			xfs_fsblock_t	bno;
5061  
5062  			bno = div_u64_rem(del->br_startblock,
5063  					mp->m_sb.sb_rextsize, &mod);
5064  			ASSERT(mod == 0);
5065  
5066  			error = xfs_rtfree_extent(tp, bno, (xfs_extlen_t)len);
5067  			if (error)
5068  				goto done;
5069  		}
5070  
5071  		do_fx = 0;
5072  		nblks = len * mp->m_sb.sb_rextsize;
5073  		qfield = XFS_TRANS_DQ_RTBCOUNT;
5074  	} else {
5075  		do_fx = 1;
5076  		nblks = del->br_blockcount;
5077  		qfield = XFS_TRANS_DQ_BCOUNT;
5078  	}
5079  
5080  	del_endblock = del->br_startblock + del->br_blockcount;
5081  	if (cur) {
5082  		error = xfs_bmbt_lookup_eq(cur, &got, &i);
5083  		if (error)
5084  			goto done;
5085  		if (XFS_IS_CORRUPT(mp, i != 1)) {
5086  			error = -EFSCORRUPTED;
5087  			goto done;
5088  		}
5089  	}
5090  
5091  	if (got.br_startoff == del->br_startoff)
5092  		state |= BMAP_LEFT_FILLING;
5093  	if (got_endoff == del_endoff)
5094  		state |= BMAP_RIGHT_FILLING;
5095  
5096  	switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
5097  	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
5098  		/*
5099  		 * Matches the whole extent.  Delete the entry.
5100  		 */
5101  		xfs_iext_remove(ip, icur, state);
5102  		xfs_iext_prev(ifp, icur);
5103  		ifp->if_nextents--;
5104  
5105  		flags |= XFS_ILOG_CORE;
5106  		if (!cur) {
5107  			flags |= xfs_ilog_fext(whichfork);
5108  			break;
5109  		}
5110  		if ((error = xfs_btree_delete(cur, &i)))
5111  			goto done;
5112  		if (XFS_IS_CORRUPT(mp, i != 1)) {
5113  			error = -EFSCORRUPTED;
5114  			goto done;
5115  		}
5116  		break;
5117  	case BMAP_LEFT_FILLING:
5118  		/*
5119  		 * Deleting the first part of the extent.
5120  		 */
5121  		got.br_startoff = del_endoff;
5122  		got.br_startblock = del_endblock;
5123  		got.br_blockcount -= del->br_blockcount;
5124  		xfs_iext_update_extent(ip, state, icur, &got);
5125  		if (!cur) {
5126  			flags |= xfs_ilog_fext(whichfork);
5127  			break;
5128  		}
5129  		error = xfs_bmbt_update(cur, &got);
5130  		if (error)
5131  			goto done;
5132  		break;
5133  	case BMAP_RIGHT_FILLING:
5134  		/*
5135  		 * Deleting the last part of the extent.
5136  		 */
5137  		got.br_blockcount -= del->br_blockcount;
5138  		xfs_iext_update_extent(ip, state, icur, &got);
5139  		if (!cur) {
5140  			flags |= xfs_ilog_fext(whichfork);
5141  			break;
5142  		}
5143  		error = xfs_bmbt_update(cur, &got);
5144  		if (error)
5145  			goto done;
5146  		break;
5147  	case 0:
5148  		/*
5149  		 * Deleting the middle of the extent.
5150  		 */
5151  
5152  		old = got;
5153  
5154  		got.br_blockcount = del->br_startoff - got.br_startoff;
5155  		xfs_iext_update_extent(ip, state, icur, &got);
5156  
5157  		new.br_startoff = del_endoff;
5158  		new.br_blockcount = got_endoff - del_endoff;
5159  		new.br_state = got.br_state;
5160  		new.br_startblock = del_endblock;
5161  
5162  		flags |= XFS_ILOG_CORE;
5163  		if (cur) {
5164  			error = xfs_bmbt_update(cur, &got);
5165  			if (error)
5166  				goto done;
5167  			error = xfs_btree_increment(cur, 0, &i);
5168  			if (error)
5169  				goto done;
5170  			cur->bc_rec.b = new;
5171  			error = xfs_btree_insert(cur, &i);
5172  			if (error && error != -ENOSPC)
5173  				goto done;
5174  			/*
5175  			 * If get no-space back from btree insert, it tried a
5176  			 * split, and we have a zero block reservation.  Fix up
5177  			 * our state and return the error.
5178  			 */
5179  			if (error == -ENOSPC) {
5180  				/*
5181  				 * Reset the cursor, don't trust it after any
5182  				 * insert operation.
5183  				 */
5184  				error = xfs_bmbt_lookup_eq(cur, &got, &i);
5185  				if (error)
5186  					goto done;
5187  				if (XFS_IS_CORRUPT(mp, i != 1)) {
5188  					error = -EFSCORRUPTED;
5189  					goto done;
5190  				}
5191  				/*
5192  				 * Update the btree record back
5193  				 * to the original value.
5194  				 */
5195  				error = xfs_bmbt_update(cur, &old);
5196  				if (error)
5197  					goto done;
5198  				/*
5199  				 * Reset the extent record back
5200  				 * to the original value.
5201  				 */
5202  				xfs_iext_update_extent(ip, state, icur, &old);
5203  				flags = 0;
5204  				error = -ENOSPC;
5205  				goto done;
5206  			}
5207  			if (XFS_IS_CORRUPT(mp, i != 1)) {
5208  				error = -EFSCORRUPTED;
5209  				goto done;
5210  			}
5211  		} else
5212  			flags |= xfs_ilog_fext(whichfork);
5213  
5214  		ifp->if_nextents++;
5215  		xfs_iext_next(ifp, icur);
5216  		xfs_iext_insert(ip, icur, &new, state);
5217  		break;
5218  	}
5219  
5220  	/* remove reverse mapping */
5221  	xfs_rmap_unmap_extent(tp, ip, whichfork, del);
5222  
5223  	/*
5224  	 * If we need to, add to list of extents to delete.
5225  	 */
5226  	if (do_fx && !(bflags & XFS_BMAPI_REMAP)) {
5227  		if (xfs_is_reflink_inode(ip) && whichfork == XFS_DATA_FORK) {
5228  			xfs_refcount_decrease_extent(tp, del);
5229  		} else {
5230  			__xfs_free_extent_later(tp, del->br_startblock,
5231  					del->br_blockcount, NULL,
5232  					(bflags & XFS_BMAPI_NODISCARD) ||
5233  					del->br_state == XFS_EXT_UNWRITTEN);
5234  		}
5235  	}
5236  
5237  	/*
5238  	 * Adjust inode # blocks in the file.
5239  	 */
5240  	if (nblks)
5241  		ip->i_nblocks -= nblks;
5242  	/*
5243  	 * Adjust quota data.
5244  	 */
5245  	if (qfield && !(bflags & XFS_BMAPI_REMAP))
5246  		xfs_trans_mod_dquot_byino(tp, ip, qfield, (long)-nblks);
5247  
5248  done:
5249  	*logflagsp = flags;
5250  	return error;
5251  }
5252  
5253  /*
5254   * Unmap (remove) blocks from a file.
5255   * If nexts is nonzero then the number of extents to remove is limited to
5256   * that value.  If not all extents in the block range can be removed then
5257   * *done is set.
5258   */
5259  int						/* error */
5260  __xfs_bunmapi(
5261  	struct xfs_trans	*tp,		/* transaction pointer */
5262  	struct xfs_inode	*ip,		/* incore inode */
5263  	xfs_fileoff_t		start,		/* first file offset deleted */
5264  	xfs_filblks_t		*rlen,		/* i/o: amount remaining */
5265  	uint32_t		flags,		/* misc flags */
5266  	xfs_extnum_t		nexts)		/* number of extents max */
5267  {
5268  	struct xfs_btree_cur	*cur;		/* bmap btree cursor */
5269  	struct xfs_bmbt_irec	del;		/* extent being deleted */
5270  	int			error;		/* error return value */
5271  	xfs_extnum_t		extno;		/* extent number in list */
5272  	struct xfs_bmbt_irec	got;		/* current extent record */
5273  	struct xfs_ifork	*ifp;		/* inode fork pointer */
5274  	int			isrt;		/* freeing in rt area */
5275  	int			logflags;	/* transaction logging flags */
5276  	xfs_extlen_t		mod;		/* rt extent offset */
5277  	struct xfs_mount	*mp = ip->i_mount;
5278  	int			tmp_logflags;	/* partial logging flags */
5279  	int			wasdel;		/* was a delayed alloc extent */
5280  	int			whichfork;	/* data or attribute fork */
5281  	xfs_fsblock_t		sum;
5282  	xfs_filblks_t		len = *rlen;	/* length to unmap in file */
5283  	xfs_fileoff_t		end;
5284  	struct xfs_iext_cursor	icur;
5285  	bool			done = false;
5286  
5287  	trace_xfs_bunmap(ip, start, len, flags, _RET_IP_);
5288  
5289  	whichfork = xfs_bmapi_whichfork(flags);
5290  	ASSERT(whichfork != XFS_COW_FORK);
5291  	ifp = XFS_IFORK_PTR(ip, whichfork);
5292  	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)))
5293  		return -EFSCORRUPTED;
5294  	if (xfs_is_shutdown(mp))
5295  		return -EIO;
5296  
5297  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
5298  	ASSERT(len > 0);
5299  	ASSERT(nexts >= 0);
5300  
5301  	error = xfs_iread_extents(tp, ip, whichfork);
5302  	if (error)
5303  		return error;
5304  
5305  	if (xfs_iext_count(ifp) == 0) {
5306  		*rlen = 0;
5307  		return 0;
5308  	}
5309  	XFS_STATS_INC(mp, xs_blk_unmap);
5310  	isrt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip);
5311  	end = start + len;
5312  
5313  	if (!xfs_iext_lookup_extent_before(ip, ifp, &end, &icur, &got)) {
5314  		*rlen = 0;
5315  		return 0;
5316  	}
5317  	end--;
5318  
5319  	logflags = 0;
5320  	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
5321  		ASSERT(ifp->if_format == XFS_DINODE_FMT_BTREE);
5322  		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5323  		cur->bc_ino.flags = 0;
5324  	} else
5325  		cur = NULL;
5326  
5327  	if (isrt) {
5328  		/*
5329  		 * Synchronize by locking the bitmap inode.
5330  		 */
5331  		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
5332  		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
5333  		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
5334  		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
5335  	}
5336  
5337  	extno = 0;
5338  	while (end != (xfs_fileoff_t)-1 && end >= start &&
5339  	       (nexts == 0 || extno < nexts)) {
5340  		/*
5341  		 * Is the found extent after a hole in which end lives?
5342  		 * Just back up to the previous extent, if so.
5343  		 */
5344  		if (got.br_startoff > end &&
5345  		    !xfs_iext_prev_extent(ifp, &icur, &got)) {
5346  			done = true;
5347  			break;
5348  		}
5349  		/*
5350  		 * Is the last block of this extent before the range
5351  		 * we're supposed to delete?  If so, we're done.
5352  		 */
5353  		end = XFS_FILEOFF_MIN(end,
5354  			got.br_startoff + got.br_blockcount - 1);
5355  		if (end < start)
5356  			break;
5357  		/*
5358  		 * Then deal with the (possibly delayed) allocated space
5359  		 * we found.
5360  		 */
5361  		del = got;
5362  		wasdel = isnullstartblock(del.br_startblock);
5363  
5364  		if (got.br_startoff < start) {
5365  			del.br_startoff = start;
5366  			del.br_blockcount -= start - got.br_startoff;
5367  			if (!wasdel)
5368  				del.br_startblock += start - got.br_startoff;
5369  		}
5370  		if (del.br_startoff + del.br_blockcount > end + 1)
5371  			del.br_blockcount = end + 1 - del.br_startoff;
5372  
5373  		if (!isrt)
5374  			goto delete;
5375  
5376  		sum = del.br_startblock + del.br_blockcount;
5377  		div_u64_rem(sum, mp->m_sb.sb_rextsize, &mod);
5378  		if (mod) {
5379  			/*
5380  			 * Realtime extent not lined up at the end.
5381  			 * The extent could have been split into written
5382  			 * and unwritten pieces, or we could just be
5383  			 * unmapping part of it.  But we can't really
5384  			 * get rid of part of a realtime extent.
5385  			 */
5386  			if (del.br_state == XFS_EXT_UNWRITTEN) {
5387  				/*
5388  				 * This piece is unwritten, or we're not
5389  				 * using unwritten extents.  Skip over it.
5390  				 */
5391  				ASSERT(end >= mod);
5392  				end -= mod > del.br_blockcount ?
5393  					del.br_blockcount : mod;
5394  				if (end < got.br_startoff &&
5395  				    !xfs_iext_prev_extent(ifp, &icur, &got)) {
5396  					done = true;
5397  					break;
5398  				}
5399  				continue;
5400  			}
5401  			/*
5402  			 * It's written, turn it unwritten.
5403  			 * This is better than zeroing it.
5404  			 */
5405  			ASSERT(del.br_state == XFS_EXT_NORM);
5406  			ASSERT(tp->t_blk_res > 0);
5407  			/*
5408  			 * If this spans a realtime extent boundary,
5409  			 * chop it back to the start of the one we end at.
5410  			 */
5411  			if (del.br_blockcount > mod) {
5412  				del.br_startoff += del.br_blockcount - mod;
5413  				del.br_startblock += del.br_blockcount - mod;
5414  				del.br_blockcount = mod;
5415  			}
5416  			del.br_state = XFS_EXT_UNWRITTEN;
5417  			error = xfs_bmap_add_extent_unwritten_real(tp, ip,
5418  					whichfork, &icur, &cur, &del,
5419  					&logflags);
5420  			if (error)
5421  				goto error0;
5422  			goto nodelete;
5423  		}
5424  		div_u64_rem(del.br_startblock, mp->m_sb.sb_rextsize, &mod);
5425  		if (mod) {
5426  			xfs_extlen_t off = mp->m_sb.sb_rextsize - mod;
5427  
5428  			/*
5429  			 * Realtime extent is lined up at the end but not
5430  			 * at the front.  We'll get rid of full extents if
5431  			 * we can.
5432  			 */
5433  			if (del.br_blockcount > off) {
5434  				del.br_blockcount -= off;
5435  				del.br_startoff += off;
5436  				del.br_startblock += off;
5437  			} else if (del.br_startoff == start &&
5438  				   (del.br_state == XFS_EXT_UNWRITTEN ||
5439  				    tp->t_blk_res == 0)) {
5440  				/*
5441  				 * Can't make it unwritten.  There isn't
5442  				 * a full extent here so just skip it.
5443  				 */
5444  				ASSERT(end >= del.br_blockcount);
5445  				end -= del.br_blockcount;
5446  				if (got.br_startoff > end &&
5447  				    !xfs_iext_prev_extent(ifp, &icur, &got)) {
5448  					done = true;
5449  					break;
5450  				}
5451  				continue;
5452  			} else if (del.br_state == XFS_EXT_UNWRITTEN) {
5453  				struct xfs_bmbt_irec	prev;
5454  				xfs_fileoff_t		unwrite_start;
5455  
5456  				/*
5457  				 * This one is already unwritten.
5458  				 * It must have a written left neighbor.
5459  				 * Unwrite the killed part of that one and
5460  				 * try again.
5461  				 */
5462  				if (!xfs_iext_prev_extent(ifp, &icur, &prev))
5463  					ASSERT(0);
5464  				ASSERT(prev.br_state == XFS_EXT_NORM);
5465  				ASSERT(!isnullstartblock(prev.br_startblock));
5466  				ASSERT(del.br_startblock ==
5467  				       prev.br_startblock + prev.br_blockcount);
5468  				unwrite_start = max3(start,
5469  						     del.br_startoff - mod,
5470  						     prev.br_startoff);
5471  				mod = unwrite_start - prev.br_startoff;
5472  				prev.br_startoff = unwrite_start;
5473  				prev.br_startblock += mod;
5474  				prev.br_blockcount -= mod;
5475  				prev.br_state = XFS_EXT_UNWRITTEN;
5476  				error = xfs_bmap_add_extent_unwritten_real(tp,
5477  						ip, whichfork, &icur, &cur,
5478  						&prev, &logflags);
5479  				if (error)
5480  					goto error0;
5481  				goto nodelete;
5482  			} else {
5483  				ASSERT(del.br_state == XFS_EXT_NORM);
5484  				del.br_state = XFS_EXT_UNWRITTEN;
5485  				error = xfs_bmap_add_extent_unwritten_real(tp,
5486  						ip, whichfork, &icur, &cur,
5487  						&del, &logflags);
5488  				if (error)
5489  					goto error0;
5490  				goto nodelete;
5491  			}
5492  		}
5493  
5494  delete:
5495  		if (wasdel) {
5496  			error = xfs_bmap_del_extent_delay(ip, whichfork, &icur,
5497  					&got, &del);
5498  		} else {
5499  			error = xfs_bmap_del_extent_real(ip, tp, &icur, cur,
5500  					&del, &tmp_logflags, whichfork,
5501  					flags);
5502  			logflags |= tmp_logflags;
5503  		}
5504  
5505  		if (error)
5506  			goto error0;
5507  
5508  		end = del.br_startoff - 1;
5509  nodelete:
5510  		/*
5511  		 * If not done go on to the next (previous) record.
5512  		 */
5513  		if (end != (xfs_fileoff_t)-1 && end >= start) {
5514  			if (!xfs_iext_get_extent(ifp, &icur, &got) ||
5515  			    (got.br_startoff > end &&
5516  			     !xfs_iext_prev_extent(ifp, &icur, &got))) {
5517  				done = true;
5518  				break;
5519  			}
5520  			extno++;
5521  		}
5522  	}
5523  	if (done || end == (xfs_fileoff_t)-1 || end < start)
5524  		*rlen = 0;
5525  	else
5526  		*rlen = end - start + 1;
5527  
5528  	/*
5529  	 * Convert to a btree if necessary.
5530  	 */
5531  	if (xfs_bmap_needs_btree(ip, whichfork)) {
5532  		ASSERT(cur == NULL);
5533  		error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
5534  				&tmp_logflags, whichfork);
5535  		logflags |= tmp_logflags;
5536  	} else {
5537  		error = xfs_bmap_btree_to_extents(tp, ip, cur, &logflags,
5538  			whichfork);
5539  	}
5540  
5541  error0:
5542  	/*
5543  	 * Log everything.  Do this after conversion, there's no point in
5544  	 * logging the extent records if we've converted to btree format.
5545  	 */
5546  	if ((logflags & xfs_ilog_fext(whichfork)) &&
5547  	    ifp->if_format != XFS_DINODE_FMT_EXTENTS)
5548  		logflags &= ~xfs_ilog_fext(whichfork);
5549  	else if ((logflags & xfs_ilog_fbroot(whichfork)) &&
5550  		 ifp->if_format != XFS_DINODE_FMT_BTREE)
5551  		logflags &= ~xfs_ilog_fbroot(whichfork);
5552  	/*
5553  	 * Log inode even in the error case, if the transaction
5554  	 * is dirty we'll need to shut down the filesystem.
5555  	 */
5556  	if (logflags)
5557  		xfs_trans_log_inode(tp, ip, logflags);
5558  	if (cur) {
5559  		if (!error)
5560  			cur->bc_ino.allocated = 0;
5561  		xfs_btree_del_cursor(cur, error);
5562  	}
5563  	return error;
5564  }
5565  
5566  /* Unmap a range of a file. */
5567  int
5568  xfs_bunmapi(
5569  	xfs_trans_t		*tp,
5570  	struct xfs_inode	*ip,
5571  	xfs_fileoff_t		bno,
5572  	xfs_filblks_t		len,
5573  	uint32_t		flags,
5574  	xfs_extnum_t		nexts,
5575  	int			*done)
5576  {
5577  	int			error;
5578  
5579  	error = __xfs_bunmapi(tp, ip, bno, &len, flags, nexts);
5580  	*done = (len == 0);
5581  	return error;
5582  }
5583  
5584  /*
5585   * Determine whether an extent shift can be accomplished by a merge with the
5586   * extent that precedes the target hole of the shift.
5587   */
5588  STATIC bool
5589  xfs_bmse_can_merge(
5590  	struct xfs_bmbt_irec	*left,	/* preceding extent */
5591  	struct xfs_bmbt_irec	*got,	/* current extent to shift */
5592  	xfs_fileoff_t		shift)	/* shift fsb */
5593  {
5594  	xfs_fileoff_t		startoff;
5595  
5596  	startoff = got->br_startoff - shift;
5597  
5598  	/*
5599  	 * The extent, once shifted, must be adjacent in-file and on-disk with
5600  	 * the preceding extent.
5601  	 */
5602  	if ((left->br_startoff + left->br_blockcount != startoff) ||
5603  	    (left->br_startblock + left->br_blockcount != got->br_startblock) ||
5604  	    (left->br_state != got->br_state) ||
5605  	    (left->br_blockcount + got->br_blockcount > XFS_MAX_BMBT_EXTLEN))
5606  		return false;
5607  
5608  	return true;
5609  }
5610  
5611  /*
5612   * A bmap extent shift adjusts the file offset of an extent to fill a preceding
5613   * hole in the file. If an extent shift would result in the extent being fully
5614   * adjacent to the extent that currently precedes the hole, we can merge with
5615   * the preceding extent rather than do the shift.
5616   *
5617   * This function assumes the caller has verified a shift-by-merge is possible
5618   * with the provided extents via xfs_bmse_can_merge().
5619   */
5620  STATIC int
5621  xfs_bmse_merge(
5622  	struct xfs_trans		*tp,
5623  	struct xfs_inode		*ip,
5624  	int				whichfork,
5625  	xfs_fileoff_t			shift,		/* shift fsb */
5626  	struct xfs_iext_cursor		*icur,
5627  	struct xfs_bmbt_irec		*got,		/* extent to shift */
5628  	struct xfs_bmbt_irec		*left,		/* preceding extent */
5629  	struct xfs_btree_cur		*cur,
5630  	int				*logflags)	/* output */
5631  {
5632  	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, whichfork);
5633  	struct xfs_bmbt_irec		new;
5634  	xfs_filblks_t			blockcount;
5635  	int				error, i;
5636  	struct xfs_mount		*mp = ip->i_mount;
5637  
5638  	blockcount = left->br_blockcount + got->br_blockcount;
5639  
5640  	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
5641  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
5642  	ASSERT(xfs_bmse_can_merge(left, got, shift));
5643  
5644  	new = *left;
5645  	new.br_blockcount = blockcount;
5646  
5647  	/*
5648  	 * Update the on-disk extent count, the btree if necessary and log the
5649  	 * inode.
5650  	 */
5651  	ifp->if_nextents--;
5652  	*logflags |= XFS_ILOG_CORE;
5653  	if (!cur) {
5654  		*logflags |= XFS_ILOG_DEXT;
5655  		goto done;
5656  	}
5657  
5658  	/* lookup and remove the extent to merge */
5659  	error = xfs_bmbt_lookup_eq(cur, got, &i);
5660  	if (error)
5661  		return error;
5662  	if (XFS_IS_CORRUPT(mp, i != 1))
5663  		return -EFSCORRUPTED;
5664  
5665  	error = xfs_btree_delete(cur, &i);
5666  	if (error)
5667  		return error;
5668  	if (XFS_IS_CORRUPT(mp, i != 1))
5669  		return -EFSCORRUPTED;
5670  
5671  	/* lookup and update size of the previous extent */
5672  	error = xfs_bmbt_lookup_eq(cur, left, &i);
5673  	if (error)
5674  		return error;
5675  	if (XFS_IS_CORRUPT(mp, i != 1))
5676  		return -EFSCORRUPTED;
5677  
5678  	error = xfs_bmbt_update(cur, &new);
5679  	if (error)
5680  		return error;
5681  
5682  	/* change to extent format if required after extent removal */
5683  	error = xfs_bmap_btree_to_extents(tp, ip, cur, logflags, whichfork);
5684  	if (error)
5685  		return error;
5686  
5687  done:
5688  	xfs_iext_remove(ip, icur, 0);
5689  	xfs_iext_prev(ifp, icur);
5690  	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), icur,
5691  			&new);
5692  
5693  	/* update reverse mapping. rmap functions merge the rmaps for us */
5694  	xfs_rmap_unmap_extent(tp, ip, whichfork, got);
5695  	memcpy(&new, got, sizeof(new));
5696  	new.br_startoff = left->br_startoff + left->br_blockcount;
5697  	xfs_rmap_map_extent(tp, ip, whichfork, &new);
5698  	return 0;
5699  }
5700  
5701  static int
5702  xfs_bmap_shift_update_extent(
5703  	struct xfs_trans	*tp,
5704  	struct xfs_inode	*ip,
5705  	int			whichfork,
5706  	struct xfs_iext_cursor	*icur,
5707  	struct xfs_bmbt_irec	*got,
5708  	struct xfs_btree_cur	*cur,
5709  	int			*logflags,
5710  	xfs_fileoff_t		startoff)
5711  {
5712  	struct xfs_mount	*mp = ip->i_mount;
5713  	struct xfs_bmbt_irec	prev = *got;
5714  	int			error, i;
5715  
5716  	*logflags |= XFS_ILOG_CORE;
5717  
5718  	got->br_startoff = startoff;
5719  
5720  	if (cur) {
5721  		error = xfs_bmbt_lookup_eq(cur, &prev, &i);
5722  		if (error)
5723  			return error;
5724  		if (XFS_IS_CORRUPT(mp, i != 1))
5725  			return -EFSCORRUPTED;
5726  
5727  		error = xfs_bmbt_update(cur, got);
5728  		if (error)
5729  			return error;
5730  	} else {
5731  		*logflags |= XFS_ILOG_DEXT;
5732  	}
5733  
5734  	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), icur,
5735  			got);
5736  
5737  	/* update reverse mapping */
5738  	xfs_rmap_unmap_extent(tp, ip, whichfork, &prev);
5739  	xfs_rmap_map_extent(tp, ip, whichfork, got);
5740  	return 0;
5741  }
5742  
5743  int
5744  xfs_bmap_collapse_extents(
5745  	struct xfs_trans	*tp,
5746  	struct xfs_inode	*ip,
5747  	xfs_fileoff_t		*next_fsb,
5748  	xfs_fileoff_t		offset_shift_fsb,
5749  	bool			*done)
5750  {
5751  	int			whichfork = XFS_DATA_FORK;
5752  	struct xfs_mount	*mp = ip->i_mount;
5753  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
5754  	struct xfs_btree_cur	*cur = NULL;
5755  	struct xfs_bmbt_irec	got, prev;
5756  	struct xfs_iext_cursor	icur;
5757  	xfs_fileoff_t		new_startoff;
5758  	int			error = 0;
5759  	int			logflags = 0;
5760  
5761  	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
5762  	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
5763  		return -EFSCORRUPTED;
5764  	}
5765  
5766  	if (xfs_is_shutdown(mp))
5767  		return -EIO;
5768  
5769  	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL));
5770  
5771  	error = xfs_iread_extents(tp, ip, whichfork);
5772  	if (error)
5773  		return error;
5774  
5775  	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
5776  		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5777  		cur->bc_ino.flags = 0;
5778  	}
5779  
5780  	if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &icur, &got)) {
5781  		*done = true;
5782  		goto del_cursor;
5783  	}
5784  	if (XFS_IS_CORRUPT(mp, isnullstartblock(got.br_startblock))) {
5785  		error = -EFSCORRUPTED;
5786  		goto del_cursor;
5787  	}
5788  
5789  	new_startoff = got.br_startoff - offset_shift_fsb;
5790  	if (xfs_iext_peek_prev_extent(ifp, &icur, &prev)) {
5791  		if (new_startoff < prev.br_startoff + prev.br_blockcount) {
5792  			error = -EINVAL;
5793  			goto del_cursor;
5794  		}
5795  
5796  		if (xfs_bmse_can_merge(&prev, &got, offset_shift_fsb)) {
5797  			error = xfs_bmse_merge(tp, ip, whichfork,
5798  					offset_shift_fsb, &icur, &got, &prev,
5799  					cur, &logflags);
5800  			if (error)
5801  				goto del_cursor;
5802  			goto done;
5803  		}
5804  	} else {
5805  		if (got.br_startoff < offset_shift_fsb) {
5806  			error = -EINVAL;
5807  			goto del_cursor;
5808  		}
5809  	}
5810  
5811  	error = xfs_bmap_shift_update_extent(tp, ip, whichfork, &icur, &got,
5812  			cur, &logflags, new_startoff);
5813  	if (error)
5814  		goto del_cursor;
5815  
5816  done:
5817  	if (!xfs_iext_next_extent(ifp, &icur, &got)) {
5818  		*done = true;
5819  		goto del_cursor;
5820  	}
5821  
5822  	*next_fsb = got.br_startoff;
5823  del_cursor:
5824  	if (cur)
5825  		xfs_btree_del_cursor(cur, error);
5826  	if (logflags)
5827  		xfs_trans_log_inode(tp, ip, logflags);
5828  	return error;
5829  }
5830  
5831  /* Make sure we won't be right-shifting an extent past the maximum bound. */
5832  int
5833  xfs_bmap_can_insert_extents(
5834  	struct xfs_inode	*ip,
5835  	xfs_fileoff_t		off,
5836  	xfs_fileoff_t		shift)
5837  {
5838  	struct xfs_bmbt_irec	got;
5839  	int			is_empty;
5840  	int			error = 0;
5841  
5842  	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
5843  
5844  	if (xfs_is_shutdown(ip->i_mount))
5845  		return -EIO;
5846  
5847  	xfs_ilock(ip, XFS_ILOCK_EXCL);
5848  	error = xfs_bmap_last_extent(NULL, ip, XFS_DATA_FORK, &got, &is_empty);
5849  	if (!error && !is_empty && got.br_startoff >= off &&
5850  	    ((got.br_startoff + shift) & BMBT_STARTOFF_MASK) < got.br_startoff)
5851  		error = -EINVAL;
5852  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
5853  
5854  	return error;
5855  }
5856  
5857  int
5858  xfs_bmap_insert_extents(
5859  	struct xfs_trans	*tp,
5860  	struct xfs_inode	*ip,
5861  	xfs_fileoff_t		*next_fsb,
5862  	xfs_fileoff_t		offset_shift_fsb,
5863  	bool			*done,
5864  	xfs_fileoff_t		stop_fsb)
5865  {
5866  	int			whichfork = XFS_DATA_FORK;
5867  	struct xfs_mount	*mp = ip->i_mount;
5868  	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
5869  	struct xfs_btree_cur	*cur = NULL;
5870  	struct xfs_bmbt_irec	got, next;
5871  	struct xfs_iext_cursor	icur;
5872  	xfs_fileoff_t		new_startoff;
5873  	int			error = 0;
5874  	int			logflags = 0;
5875  
5876  	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
5877  	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
5878  		return -EFSCORRUPTED;
5879  	}
5880  
5881  	if (xfs_is_shutdown(mp))
5882  		return -EIO;
5883  
5884  	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL));
5885  
5886  	error = xfs_iread_extents(tp, ip, whichfork);
5887  	if (error)
5888  		return error;
5889  
5890  	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
5891  		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5892  		cur->bc_ino.flags = 0;
5893  	}
5894  
5895  	if (*next_fsb == NULLFSBLOCK) {
5896  		xfs_iext_last(ifp, &icur);
5897  		if (!xfs_iext_get_extent(ifp, &icur, &got) ||
5898  		    stop_fsb > got.br_startoff) {
5899  			*done = true;
5900  			goto del_cursor;
5901  		}
5902  	} else {
5903  		if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &icur, &got)) {
5904  			*done = true;
5905  			goto del_cursor;
5906  		}
5907  	}
5908  	if (XFS_IS_CORRUPT(mp, isnullstartblock(got.br_startblock))) {
5909  		error = -EFSCORRUPTED;
5910  		goto del_cursor;
5911  	}
5912  
5913  	if (XFS_IS_CORRUPT(mp, stop_fsb > got.br_startoff)) {
5914  		error = -EFSCORRUPTED;
5915  		goto del_cursor;
5916  	}
5917  
5918  	new_startoff = got.br_startoff + offset_shift_fsb;
5919  	if (xfs_iext_peek_next_extent(ifp, &icur, &next)) {
5920  		if (new_startoff + got.br_blockcount > next.br_startoff) {
5921  			error = -EINVAL;
5922  			goto del_cursor;
5923  		}
5924  
5925  		/*
5926  		 * Unlike a left shift (which involves a hole punch), a right
5927  		 * shift does not modify extent neighbors in any way.  We should
5928  		 * never find mergeable extents in this scenario.  Check anyways
5929  		 * and warn if we encounter two extents that could be one.
5930  		 */
5931  		if (xfs_bmse_can_merge(&got, &next, offset_shift_fsb))
5932  			WARN_ON_ONCE(1);
5933  	}
5934  
5935  	error = xfs_bmap_shift_update_extent(tp, ip, whichfork, &icur, &got,
5936  			cur, &logflags, new_startoff);
5937  	if (error)
5938  		goto del_cursor;
5939  
5940  	if (!xfs_iext_prev_extent(ifp, &icur, &got) ||
5941  	    stop_fsb >= got.br_startoff + got.br_blockcount) {
5942  		*done = true;
5943  		goto del_cursor;
5944  	}
5945  
5946  	*next_fsb = got.br_startoff;
5947  del_cursor:
5948  	if (cur)
5949  		xfs_btree_del_cursor(cur, error);
5950  	if (logflags)
5951  		xfs_trans_log_inode(tp, ip, logflags);
5952  	return error;
5953  }
5954  
5955  /*
5956   * Splits an extent into two extents at split_fsb block such that it is the
5957   * first block of the current_ext. @ext is a target extent to be split.
5958   * @split_fsb is a block where the extents is split.  If split_fsb lies in a
5959   * hole or the first block of extents, just return 0.
5960   */
5961  int
5962  xfs_bmap_split_extent(
5963  	struct xfs_trans	*tp,
5964  	struct xfs_inode	*ip,
5965  	xfs_fileoff_t		split_fsb)
5966  {
5967  	int				whichfork = XFS_DATA_FORK;
5968  	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, whichfork);
5969  	struct xfs_btree_cur		*cur = NULL;
5970  	struct xfs_bmbt_irec		got;
5971  	struct xfs_bmbt_irec		new; /* split extent */
5972  	struct xfs_mount		*mp = ip->i_mount;
5973  	xfs_fsblock_t			gotblkcnt; /* new block count for got */
5974  	struct xfs_iext_cursor		icur;
5975  	int				error = 0;
5976  	int				logflags = 0;
5977  	int				i = 0;
5978  
5979  	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
5980  	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
5981  		return -EFSCORRUPTED;
5982  	}
5983  
5984  	if (xfs_is_shutdown(mp))
5985  		return -EIO;
5986  
5987  	/* Read in all the extents */
5988  	error = xfs_iread_extents(tp, ip, whichfork);
5989  	if (error)
5990  		return error;
5991  
5992  	/*
5993  	 * If there are not extents, or split_fsb lies in a hole we are done.
5994  	 */
5995  	if (!xfs_iext_lookup_extent(ip, ifp, split_fsb, &icur, &got) ||
5996  	    got.br_startoff >= split_fsb)
5997  		return 0;
5998  
5999  	gotblkcnt = split_fsb - got.br_startoff;
6000  	new.br_startoff = split_fsb;
6001  	new.br_startblock = got.br_startblock + gotblkcnt;
6002  	new.br_blockcount = got.br_blockcount - gotblkcnt;
6003  	new.br_state = got.br_state;
6004  
6005  	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
6006  		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
6007  		cur->bc_ino.flags = 0;
6008  		error = xfs_bmbt_lookup_eq(cur, &got, &i);
6009  		if (error)
6010  			goto del_cursor;
6011  		if (XFS_IS_CORRUPT(mp, i != 1)) {
6012  			error = -EFSCORRUPTED;
6013  			goto del_cursor;
6014  		}
6015  	}
6016  
6017  	got.br_blockcount = gotblkcnt;
6018  	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), &icur,
6019  			&got);
6020  
6021  	logflags = XFS_ILOG_CORE;
6022  	if (cur) {
6023  		error = xfs_bmbt_update(cur, &got);
6024  		if (error)
6025  			goto del_cursor;
6026  	} else
6027  		logflags |= XFS_ILOG_DEXT;
6028  
6029  	/* Add new extent */
6030  	xfs_iext_next(ifp, &icur);
6031  	xfs_iext_insert(ip, &icur, &new, 0);
6032  	ifp->if_nextents++;
6033  
6034  	if (cur) {
6035  		error = xfs_bmbt_lookup_eq(cur, &new, &i);
6036  		if (error)
6037  			goto del_cursor;
6038  		if (XFS_IS_CORRUPT(mp, i != 0)) {
6039  			error = -EFSCORRUPTED;
6040  			goto del_cursor;
6041  		}
6042  		error = xfs_btree_insert(cur, &i);
6043  		if (error)
6044  			goto del_cursor;
6045  		if (XFS_IS_CORRUPT(mp, i != 1)) {
6046  			error = -EFSCORRUPTED;
6047  			goto del_cursor;
6048  		}
6049  	}
6050  
6051  	/*
6052  	 * Convert to a btree if necessary.
6053  	 */
6054  	if (xfs_bmap_needs_btree(ip, whichfork)) {
6055  		int tmp_logflags; /* partial log flag return val */
6056  
6057  		ASSERT(cur == NULL);
6058  		error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
6059  				&tmp_logflags, whichfork);
6060  		logflags |= tmp_logflags;
6061  	}
6062  
6063  del_cursor:
6064  	if (cur) {
6065  		cur->bc_ino.allocated = 0;
6066  		xfs_btree_del_cursor(cur, error);
6067  	}
6068  
6069  	if (logflags)
6070  		xfs_trans_log_inode(tp, ip, logflags);
6071  	return error;
6072  }
6073  
6074  /* Deferred mapping is only for real extents in the data fork. */
6075  static bool
6076  xfs_bmap_is_update_needed(
6077  	struct xfs_bmbt_irec	*bmap)
6078  {
6079  	return  bmap->br_startblock != HOLESTARTBLOCK &&
6080  		bmap->br_startblock != DELAYSTARTBLOCK;
6081  }
6082  
6083  /* Record a bmap intent. */
6084  static int
6085  __xfs_bmap_add(
6086  	struct xfs_trans		*tp,
6087  	enum xfs_bmap_intent_type	type,
6088  	struct xfs_inode		*ip,
6089  	int				whichfork,
6090  	struct xfs_bmbt_irec		*bmap)
6091  {
6092  	struct xfs_bmap_intent		*bi;
6093  
6094  	trace_xfs_bmap_defer(tp->t_mountp,
6095  			XFS_FSB_TO_AGNO(tp->t_mountp, bmap->br_startblock),
6096  			type,
6097  			XFS_FSB_TO_AGBNO(tp->t_mountp, bmap->br_startblock),
6098  			ip->i_ino, whichfork,
6099  			bmap->br_startoff,
6100  			bmap->br_blockcount,
6101  			bmap->br_state);
6102  
6103  	bi = kmem_cache_alloc(xfs_bmap_intent_cache, GFP_NOFS | __GFP_NOFAIL);
6104  	INIT_LIST_HEAD(&bi->bi_list);
6105  	bi->bi_type = type;
6106  	bi->bi_owner = ip;
6107  	bi->bi_whichfork = whichfork;
6108  	bi->bi_bmap = *bmap;
6109  
6110  	xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_BMAP, &bi->bi_list);
6111  	return 0;
6112  }
6113  
6114  /* Map an extent into a file. */
6115  void
6116  xfs_bmap_map_extent(
6117  	struct xfs_trans	*tp,
6118  	struct xfs_inode	*ip,
6119  	struct xfs_bmbt_irec	*PREV)
6120  {
6121  	if (!xfs_bmap_is_update_needed(PREV))
6122  		return;
6123  
6124  	__xfs_bmap_add(tp, XFS_BMAP_MAP, ip, XFS_DATA_FORK, PREV);
6125  }
6126  
6127  /* Unmap an extent out of a file. */
6128  void
6129  xfs_bmap_unmap_extent(
6130  	struct xfs_trans	*tp,
6131  	struct xfs_inode	*ip,
6132  	struct xfs_bmbt_irec	*PREV)
6133  {
6134  	if (!xfs_bmap_is_update_needed(PREV))
6135  		return;
6136  
6137  	__xfs_bmap_add(tp, XFS_BMAP_UNMAP, ip, XFS_DATA_FORK, PREV);
6138  }
6139  
6140  /*
6141   * Process one of the deferred bmap operations.  We pass back the
6142   * btree cursor to maintain our lock on the bmapbt between calls.
6143   */
6144  int
6145  xfs_bmap_finish_one(
6146  	struct xfs_trans		*tp,
6147  	struct xfs_inode		*ip,
6148  	enum xfs_bmap_intent_type	type,
6149  	int				whichfork,
6150  	xfs_fileoff_t			startoff,
6151  	xfs_fsblock_t			startblock,
6152  	xfs_filblks_t			*blockcount,
6153  	xfs_exntst_t			state)
6154  {
6155  	int				error = 0;
6156  
6157  	ASSERT(tp->t_firstblock == NULLFSBLOCK);
6158  
6159  	trace_xfs_bmap_deferred(tp->t_mountp,
6160  			XFS_FSB_TO_AGNO(tp->t_mountp, startblock), type,
6161  			XFS_FSB_TO_AGBNO(tp->t_mountp, startblock),
6162  			ip->i_ino, whichfork, startoff, *blockcount, state);
6163  
6164  	if (WARN_ON_ONCE(whichfork != XFS_DATA_FORK))
6165  		return -EFSCORRUPTED;
6166  
6167  	if (XFS_TEST_ERROR(false, tp->t_mountp,
6168  			XFS_ERRTAG_BMAP_FINISH_ONE))
6169  		return -EIO;
6170  
6171  	switch (type) {
6172  	case XFS_BMAP_MAP:
6173  		error = xfs_bmapi_remap(tp, ip, startoff, *blockcount,
6174  				startblock, 0);
6175  		*blockcount = 0;
6176  		break;
6177  	case XFS_BMAP_UNMAP:
6178  		error = __xfs_bunmapi(tp, ip, startoff, blockcount,
6179  				XFS_BMAPI_REMAP, 1);
6180  		break;
6181  	default:
6182  		ASSERT(0);
6183  		error = -EFSCORRUPTED;
6184  	}
6185  
6186  	return error;
6187  }
6188  
6189  /* Check that an inode's extent does not have invalid flags or bad ranges. */
6190  xfs_failaddr_t
6191  xfs_bmap_validate_extent(
6192  	struct xfs_inode	*ip,
6193  	int			whichfork,
6194  	struct xfs_bmbt_irec	*irec)
6195  {
6196  	struct xfs_mount	*mp = ip->i_mount;
6197  
6198  	if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
6199  		return __this_address;
6200  
6201  	if (XFS_IS_REALTIME_INODE(ip) && whichfork == XFS_DATA_FORK) {
6202  		if (!xfs_verify_rtext(mp, irec->br_startblock,
6203  					  irec->br_blockcount))
6204  			return __this_address;
6205  	} else {
6206  		if (!xfs_verify_fsbext(mp, irec->br_startblock,
6207  					   irec->br_blockcount))
6208  			return __this_address;
6209  	}
6210  	if (irec->br_state != XFS_EXT_NORM && whichfork != XFS_DATA_FORK)
6211  		return __this_address;
6212  	return NULL;
6213  }
6214  
6215  int __init
6216  xfs_bmap_intent_init_cache(void)
6217  {
6218  	xfs_bmap_intent_cache = kmem_cache_create("xfs_bmap_intent",
6219  			sizeof(struct xfs_bmap_intent),
6220  			0, 0, NULL);
6221  
6222  	return xfs_bmap_intent_cache != NULL ? 0 : -ENOMEM;
6223  }
6224  
6225  void
6226  xfs_bmap_intent_destroy_cache(void)
6227  {
6228  	kmem_cache_destroy(xfs_bmap_intent_cache);
6229  	xfs_bmap_intent_cache = NULL;
6230  }
6231