xref: /linux/fs/xfs/libxfs/xfs_bmap.c (revision 7255fcc80d4b525cc10cfaaf7f485830d4ed2000)
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_rtbitmap.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 #include "xfs_health.h"
40 #include "xfs_bmap_item.h"
41 #include "xfs_symlink_remote.h"
42 
43 struct kmem_cache		*xfs_bmap_intent_cache;
44 
45 /*
46  * Miscellaneous helper functions
47  */
48 
49 /*
50  * Compute and fill in the value of the maximum depth of a bmap btree
51  * in this filesystem.  Done once, during mount.
52  */
53 void
54 xfs_bmap_compute_maxlevels(
55 	xfs_mount_t	*mp,		/* file system mount structure */
56 	int		whichfork)	/* data or attr fork */
57 {
58 	uint64_t	maxblocks;	/* max blocks at this level */
59 	xfs_extnum_t	maxleafents;	/* max leaf entries possible */
60 	int		level;		/* btree level */
61 	int		maxrootrecs;	/* max records in root block */
62 	int		minleafrecs;	/* min records in leaf block */
63 	int		minnoderecs;	/* min records in node block */
64 	int		sz;		/* root block size */
65 
66 	/*
67 	 * The maximum number of extents in a fork, hence the maximum number of
68 	 * leaf entries, is controlled by the size of the on-disk extent count.
69 	 *
70 	 * Note that we can no longer assume that if we are in ATTR1 that the
71 	 * fork offset of all the inodes will be
72 	 * (xfs_default_attroffset(ip) >> 3) because we could have mounted with
73 	 * ATTR2 and then mounted back with ATTR1, keeping the i_forkoff's fixed
74 	 * but probably at various positions. Therefore, for both ATTR1 and
75 	 * ATTR2 we have to assume the worst case scenario of a minimum size
76 	 * available.
77 	 */
78 	maxleafents = xfs_iext_max_nextents(xfs_has_large_extent_counts(mp),
79 				whichfork);
80 	if (whichfork == XFS_DATA_FORK)
81 		sz = XFS_BMDR_SPACE_CALC(MINDBTPTRS);
82 	else
83 		sz = XFS_BMDR_SPACE_CALC(MINABTPTRS);
84 
85 	maxrootrecs = xfs_bmdr_maxrecs(sz, 0);
86 	minleafrecs = mp->m_bmap_dmnr[0];
87 	minnoderecs = mp->m_bmap_dmnr[1];
88 	maxblocks = howmany_64(maxleafents, minleafrecs);
89 	for (level = 1; maxblocks > 1; level++) {
90 		if (maxblocks <= maxrootrecs)
91 			maxblocks = 1;
92 		else
93 			maxblocks = howmany_64(maxblocks, minnoderecs);
94 	}
95 	mp->m_bm_maxlevels[whichfork] = level;
96 	ASSERT(mp->m_bm_maxlevels[whichfork] <= xfs_bmbt_maxlevels_ondisk());
97 }
98 
99 unsigned int
100 xfs_bmap_compute_attr_offset(
101 	struct xfs_mount	*mp)
102 {
103 	if (mp->m_sb.sb_inodesize == 256)
104 		return XFS_LITINO(mp) - XFS_BMDR_SPACE_CALC(MINABTPTRS);
105 	return XFS_BMDR_SPACE_CALC(6 * MINABTPTRS);
106 }
107 
108 STATIC int				/* error */
109 xfs_bmbt_lookup_eq(
110 	struct xfs_btree_cur	*cur,
111 	struct xfs_bmbt_irec	*irec,
112 	int			*stat)	/* success/failure */
113 {
114 	cur->bc_rec.b = *irec;
115 	return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
116 }
117 
118 STATIC int				/* error */
119 xfs_bmbt_lookup_first(
120 	struct xfs_btree_cur	*cur,
121 	int			*stat)	/* success/failure */
122 {
123 	cur->bc_rec.b.br_startoff = 0;
124 	cur->bc_rec.b.br_startblock = 0;
125 	cur->bc_rec.b.br_blockcount = 0;
126 	return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
127 }
128 
129 /*
130  * Check if the inode needs to be converted to btree format.
131  */
132 static inline bool xfs_bmap_needs_btree(struct xfs_inode *ip, int whichfork)
133 {
134 	struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
135 
136 	return whichfork != XFS_COW_FORK &&
137 		ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
138 		ifp->if_nextents > XFS_IFORK_MAXEXT(ip, whichfork);
139 }
140 
141 /*
142  * Check if the inode should be converted to extent format.
143  */
144 static inline bool xfs_bmap_wants_extents(struct xfs_inode *ip, int whichfork)
145 {
146 	struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
147 
148 	return whichfork != XFS_COW_FORK &&
149 		ifp->if_format == XFS_DINODE_FMT_BTREE &&
150 		ifp->if_nextents <= XFS_IFORK_MAXEXT(ip, whichfork);
151 }
152 
153 /*
154  * Update the record referred to by cur to the value given by irec
155  * This either works (return 0) or gets an EFSCORRUPTED error.
156  */
157 STATIC int
158 xfs_bmbt_update(
159 	struct xfs_btree_cur	*cur,
160 	struct xfs_bmbt_irec	*irec)
161 {
162 	union xfs_btree_rec	rec;
163 
164 	xfs_bmbt_disk_set_all(&rec.bmbt, irec);
165 	return xfs_btree_update(cur, &rec);
166 }
167 
168 /*
169  * Compute the worst-case number of indirect blocks that will be used
170  * for ip's delayed extent of length "len".
171  */
172 STATIC xfs_filblks_t
173 xfs_bmap_worst_indlen(
174 	xfs_inode_t	*ip,		/* incore inode pointer */
175 	xfs_filblks_t	len)		/* delayed extent length */
176 {
177 	int		level;		/* btree level number */
178 	int		maxrecs;	/* maximum record count at this level */
179 	xfs_mount_t	*mp;		/* mount structure */
180 	xfs_filblks_t	rval;		/* return value */
181 
182 	mp = ip->i_mount;
183 	maxrecs = mp->m_bmap_dmxr[0];
184 	for (level = 0, rval = 0;
185 	     level < XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK);
186 	     level++) {
187 		len += maxrecs - 1;
188 		do_div(len, maxrecs);
189 		rval += len;
190 		if (len == 1)
191 			return rval + XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) -
192 				level - 1;
193 		if (level == 0)
194 			maxrecs = mp->m_bmap_dmxr[1];
195 	}
196 	return rval;
197 }
198 
199 /*
200  * Calculate the default attribute fork offset for newly created inodes.
201  */
202 uint
203 xfs_default_attroffset(
204 	struct xfs_inode	*ip)
205 {
206 	if (ip->i_df.if_format == XFS_DINODE_FMT_DEV)
207 		return roundup(sizeof(xfs_dev_t), 8);
208 	return M_IGEO(ip->i_mount)->attr_fork_offset;
209 }
210 
211 /*
212  * Helper routine to reset inode i_forkoff field when switching attribute fork
213  * from local to extent format - we reset it where possible to make space
214  * available for inline data fork extents.
215  */
216 STATIC void
217 xfs_bmap_forkoff_reset(
218 	xfs_inode_t	*ip,
219 	int		whichfork)
220 {
221 	if (whichfork == XFS_ATTR_FORK &&
222 	    ip->i_df.if_format != XFS_DINODE_FMT_DEV &&
223 	    ip->i_df.if_format != XFS_DINODE_FMT_BTREE) {
224 		uint	dfl_forkoff = xfs_default_attroffset(ip) >> 3;
225 
226 		if (dfl_forkoff > ip->i_forkoff)
227 			ip->i_forkoff = dfl_forkoff;
228 	}
229 }
230 
231 static int
232 xfs_bmap_read_buf(
233 	struct xfs_mount	*mp,		/* file system mount point */
234 	struct xfs_trans	*tp,		/* transaction pointer */
235 	xfs_fsblock_t		fsbno,		/* file system block number */
236 	struct xfs_buf		**bpp)		/* buffer for fsbno */
237 {
238 	struct xfs_buf		*bp;		/* return value */
239 	int			error;
240 
241 	if (!xfs_verify_fsbno(mp, fsbno))
242 		return -EFSCORRUPTED;
243 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
244 			XFS_FSB_TO_DADDR(mp, fsbno), mp->m_bsize, 0, &bp,
245 			&xfs_bmbt_buf_ops);
246 	if (!error) {
247 		xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
248 		*bpp = bp;
249 	}
250 	return error;
251 }
252 
253 #ifdef DEBUG
254 STATIC struct xfs_buf *
255 xfs_bmap_get_bp(
256 	struct xfs_btree_cur	*cur,
257 	xfs_fsblock_t		bno)
258 {
259 	struct xfs_log_item	*lip;
260 	int			i;
261 
262 	if (!cur)
263 		return NULL;
264 
265 	for (i = 0; i < cur->bc_maxlevels; i++) {
266 		if (!cur->bc_levels[i].bp)
267 			break;
268 		if (xfs_buf_daddr(cur->bc_levels[i].bp) == bno)
269 			return cur->bc_levels[i].bp;
270 	}
271 
272 	/* Chase down all the log items to see if the bp is there */
273 	list_for_each_entry(lip, &cur->bc_tp->t_items, li_trans) {
274 		struct xfs_buf_log_item	*bip = (struct xfs_buf_log_item *)lip;
275 
276 		if (bip->bli_item.li_type == XFS_LI_BUF &&
277 		    xfs_buf_daddr(bip->bli_buf) == bno)
278 			return bip->bli_buf;
279 	}
280 
281 	return NULL;
282 }
283 
284 STATIC void
285 xfs_check_block(
286 	struct xfs_btree_block	*block,
287 	xfs_mount_t		*mp,
288 	int			root,
289 	short			sz)
290 {
291 	int			i, j, dmxr;
292 	__be64			*pp, *thispa;	/* pointer to block address */
293 	xfs_bmbt_key_t		*prevp, *keyp;
294 
295 	ASSERT(be16_to_cpu(block->bb_level) > 0);
296 
297 	prevp = NULL;
298 	for( i = 1; i <= xfs_btree_get_numrecs(block); i++) {
299 		dmxr = mp->m_bmap_dmxr[0];
300 		keyp = XFS_BMBT_KEY_ADDR(mp, block, i);
301 
302 		if (prevp) {
303 			ASSERT(be64_to_cpu(prevp->br_startoff) <
304 			       be64_to_cpu(keyp->br_startoff));
305 		}
306 		prevp = keyp;
307 
308 		/*
309 		 * Compare the block numbers to see if there are dups.
310 		 */
311 		if (root)
312 			pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, i, sz);
313 		else
314 			pp = XFS_BMBT_PTR_ADDR(mp, block, i, dmxr);
315 
316 		for (j = i+1; j <= be16_to_cpu(block->bb_numrecs); j++) {
317 			if (root)
318 				thispa = XFS_BMAP_BROOT_PTR_ADDR(mp, block, j, sz);
319 			else
320 				thispa = XFS_BMBT_PTR_ADDR(mp, block, j, dmxr);
321 			if (*thispa == *pp) {
322 				xfs_warn(mp, "%s: thispa(%d) == pp(%d) %lld",
323 					__func__, j, i,
324 					(unsigned long long)be64_to_cpu(*thispa));
325 				xfs_err(mp, "%s: ptrs are equal in node\n",
326 					__func__);
327 				xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
328 			}
329 		}
330 	}
331 }
332 
333 /*
334  * Check that the extents for the inode ip are in the right order in all
335  * btree leaves. THis becomes prohibitively expensive for large extent count
336  * files, so don't bother with inodes that have more than 10,000 extents in
337  * them. The btree record ordering checks will still be done, so for such large
338  * bmapbt constructs that is going to catch most corruptions.
339  */
340 STATIC void
341 xfs_bmap_check_leaf_extents(
342 	struct xfs_btree_cur	*cur,	/* btree cursor or null */
343 	xfs_inode_t		*ip,		/* incore inode pointer */
344 	int			whichfork)	/* data or attr fork */
345 {
346 	struct xfs_mount	*mp = ip->i_mount;
347 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
348 	struct xfs_btree_block	*block;	/* current btree block */
349 	xfs_fsblock_t		bno;	/* block # of "block" */
350 	struct xfs_buf		*bp;	/* buffer for "block" */
351 	int			error;	/* error return value */
352 	xfs_extnum_t		i=0, j;	/* index into the extents list */
353 	int			level;	/* btree level, for checking */
354 	__be64			*pp;	/* pointer to block address */
355 	xfs_bmbt_rec_t		*ep;	/* pointer to current extent */
356 	xfs_bmbt_rec_t		last = {0, 0}; /* last extent in prev block */
357 	xfs_bmbt_rec_t		*nextp;	/* pointer to next extent */
358 	int			bp_release = 0;
359 
360 	if (ifp->if_format != XFS_DINODE_FMT_BTREE)
361 		return;
362 
363 	/* skip large extent count inodes */
364 	if (ip->i_df.if_nextents > 10000)
365 		return;
366 
367 	bno = NULLFSBLOCK;
368 	block = ifp->if_broot;
369 	/*
370 	 * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
371 	 */
372 	level = be16_to_cpu(block->bb_level);
373 	ASSERT(level > 0);
374 	xfs_check_block(block, mp, 1, ifp->if_broot_bytes);
375 	pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);
376 	bno = be64_to_cpu(*pp);
377 
378 	ASSERT(bno != NULLFSBLOCK);
379 	ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);
380 	ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);
381 
382 	/*
383 	 * Go down the tree until leaf level is reached, following the first
384 	 * pointer (leftmost) at each level.
385 	 */
386 	while (level-- > 0) {
387 		/* See if buf is in cur first */
388 		bp_release = 0;
389 		bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
390 		if (!bp) {
391 			bp_release = 1;
392 			error = xfs_bmap_read_buf(mp, NULL, bno, &bp);
393 			if (xfs_metadata_is_sick(error))
394 				xfs_btree_mark_sick(cur);
395 			if (error)
396 				goto error_norelse;
397 		}
398 		block = XFS_BUF_TO_BLOCK(bp);
399 		if (level == 0)
400 			break;
401 
402 		/*
403 		 * Check this block for basic sanity (increasing keys and
404 		 * no duplicate blocks).
405 		 */
406 
407 		xfs_check_block(block, mp, 0, 0);
408 		pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
409 		bno = be64_to_cpu(*pp);
410 		if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbno(mp, bno))) {
411 			xfs_btree_mark_sick(cur);
412 			error = -EFSCORRUPTED;
413 			goto error0;
414 		}
415 		if (bp_release) {
416 			bp_release = 0;
417 			xfs_trans_brelse(NULL, bp);
418 		}
419 	}
420 
421 	/*
422 	 * Here with bp and block set to the leftmost leaf node in the tree.
423 	 */
424 	i = 0;
425 
426 	/*
427 	 * Loop over all leaf nodes checking that all extents are in the right order.
428 	 */
429 	for (;;) {
430 		xfs_fsblock_t	nextbno;
431 		xfs_extnum_t	num_recs;
432 
433 
434 		num_recs = xfs_btree_get_numrecs(block);
435 
436 		/*
437 		 * Read-ahead the next leaf block, if any.
438 		 */
439 
440 		nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
441 
442 		/*
443 		 * Check all the extents to make sure they are OK.
444 		 * If we had a previous block, the last entry should
445 		 * conform with the first entry in this one.
446 		 */
447 
448 		ep = XFS_BMBT_REC_ADDR(mp, block, 1);
449 		if (i) {
450 			ASSERT(xfs_bmbt_disk_get_startoff(&last) +
451 			       xfs_bmbt_disk_get_blockcount(&last) <=
452 			       xfs_bmbt_disk_get_startoff(ep));
453 		}
454 		for (j = 1; j < num_recs; j++) {
455 			nextp = XFS_BMBT_REC_ADDR(mp, block, j + 1);
456 			ASSERT(xfs_bmbt_disk_get_startoff(ep) +
457 			       xfs_bmbt_disk_get_blockcount(ep) <=
458 			       xfs_bmbt_disk_get_startoff(nextp));
459 			ep = nextp;
460 		}
461 
462 		last = *ep;
463 		i += num_recs;
464 		if (bp_release) {
465 			bp_release = 0;
466 			xfs_trans_brelse(NULL, bp);
467 		}
468 		bno = nextbno;
469 		/*
470 		 * If we've reached the end, stop.
471 		 */
472 		if (bno == NULLFSBLOCK)
473 			break;
474 
475 		bp_release = 0;
476 		bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
477 		if (!bp) {
478 			bp_release = 1;
479 			error = xfs_bmap_read_buf(mp, NULL, bno, &bp);
480 			if (xfs_metadata_is_sick(error))
481 				xfs_btree_mark_sick(cur);
482 			if (error)
483 				goto error_norelse;
484 		}
485 		block = XFS_BUF_TO_BLOCK(bp);
486 	}
487 
488 	return;
489 
490 error0:
491 	xfs_warn(mp, "%s: at error0", __func__);
492 	if (bp_release)
493 		xfs_trans_brelse(NULL, bp);
494 error_norelse:
495 	xfs_warn(mp, "%s: BAD after btree leaves for %llu extents",
496 		__func__, i);
497 	xfs_err(mp, "%s: CORRUPTED BTREE OR SOMETHING", __func__);
498 	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
499 	return;
500 }
501 
502 /*
503  * Validate that the bmbt_irecs being returned from bmapi are valid
504  * given the caller's original parameters.  Specifically check the
505  * ranges of the returned irecs to ensure that they only extend beyond
506  * the given parameters if the XFS_BMAPI_ENTIRE flag was set.
507  */
508 STATIC void
509 xfs_bmap_validate_ret(
510 	xfs_fileoff_t		bno,
511 	xfs_filblks_t		len,
512 	uint32_t		flags,
513 	xfs_bmbt_irec_t		*mval,
514 	int			nmap,
515 	int			ret_nmap)
516 {
517 	int			i;		/* index to map values */
518 
519 	ASSERT(ret_nmap <= nmap);
520 
521 	for (i = 0; i < ret_nmap; i++) {
522 		ASSERT(mval[i].br_blockcount > 0);
523 		if (!(flags & XFS_BMAPI_ENTIRE)) {
524 			ASSERT(mval[i].br_startoff >= bno);
525 			ASSERT(mval[i].br_blockcount <= len);
526 			ASSERT(mval[i].br_startoff + mval[i].br_blockcount <=
527 			       bno + len);
528 		} else {
529 			ASSERT(mval[i].br_startoff < bno + len);
530 			ASSERT(mval[i].br_startoff + mval[i].br_blockcount >
531 			       bno);
532 		}
533 		ASSERT(i == 0 ||
534 		       mval[i - 1].br_startoff + mval[i - 1].br_blockcount ==
535 		       mval[i].br_startoff);
536 		ASSERT(mval[i].br_startblock != DELAYSTARTBLOCK &&
537 		       mval[i].br_startblock != HOLESTARTBLOCK);
538 		ASSERT(mval[i].br_state == XFS_EXT_NORM ||
539 		       mval[i].br_state == XFS_EXT_UNWRITTEN);
540 	}
541 }
542 
543 #else
544 #define xfs_bmap_check_leaf_extents(cur, ip, whichfork)		do { } while (0)
545 #define	xfs_bmap_validate_ret(bno,len,flags,mval,onmap,nmap)	do { } while (0)
546 #endif /* DEBUG */
547 
548 /*
549  * Inode fork format manipulation functions
550  */
551 
552 /*
553  * Convert the inode format to extent format if it currently is in btree format,
554  * but the extent list is small enough that it fits into the extent format.
555  *
556  * Since the extents are already in-core, all we have to do is give up the space
557  * for the btree root and pitch the leaf block.
558  */
559 STATIC int				/* error */
560 xfs_bmap_btree_to_extents(
561 	struct xfs_trans	*tp,	/* transaction pointer */
562 	struct xfs_inode	*ip,	/* incore inode pointer */
563 	struct xfs_btree_cur	*cur,	/* btree cursor */
564 	int			*logflagsp, /* inode logging flags */
565 	int			whichfork)  /* data or attr fork */
566 {
567 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
568 	struct xfs_mount	*mp = ip->i_mount;
569 	struct xfs_btree_block	*rblock = ifp->if_broot;
570 	struct xfs_btree_block	*cblock;/* child btree block */
571 	xfs_fsblock_t		cbno;	/* child block number */
572 	struct xfs_buf		*cbp;	/* child block's buffer */
573 	int			error;	/* error return value */
574 	__be64			*pp;	/* ptr to block address */
575 	struct xfs_owner_info	oinfo;
576 
577 	/* check if we actually need the extent format first: */
578 	if (!xfs_bmap_wants_extents(ip, whichfork))
579 		return 0;
580 
581 	ASSERT(cur);
582 	ASSERT(whichfork != XFS_COW_FORK);
583 	ASSERT(ifp->if_format == XFS_DINODE_FMT_BTREE);
584 	ASSERT(be16_to_cpu(rblock->bb_level) == 1);
585 	ASSERT(be16_to_cpu(rblock->bb_numrecs) == 1);
586 	ASSERT(xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0) == 1);
587 
588 	pp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, ifp->if_broot_bytes);
589 	cbno = be64_to_cpu(*pp);
590 #ifdef DEBUG
591 	if (XFS_IS_CORRUPT(cur->bc_mp, !xfs_verify_fsbno(mp, cbno))) {
592 		xfs_btree_mark_sick(cur);
593 		return -EFSCORRUPTED;
594 	}
595 #endif
596 	error = xfs_bmap_read_buf(mp, tp, cbno, &cbp);
597 	if (xfs_metadata_is_sick(error))
598 		xfs_btree_mark_sick(cur);
599 	if (error)
600 		return error;
601 	cblock = XFS_BUF_TO_BLOCK(cbp);
602 	if ((error = xfs_btree_check_block(cur, cblock, 0, cbp)))
603 		return error;
604 
605 	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
606 	error = xfs_free_extent_later(cur->bc_tp, cbno, 1, &oinfo,
607 			XFS_AG_RESV_NONE, false);
608 	if (error)
609 		return error;
610 
611 	ip->i_nblocks--;
612 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
613 	xfs_trans_binval(tp, cbp);
614 	if (cur->bc_levels[0].bp == cbp)
615 		cur->bc_levels[0].bp = NULL;
616 	xfs_iroot_realloc(ip, -1, whichfork);
617 	ASSERT(ifp->if_broot == NULL);
618 	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
619 	*logflagsp |= XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
620 	return 0;
621 }
622 
623 /*
624  * Convert an extents-format file into a btree-format file.
625  * The new file will have a root block (in the inode) and a single child block.
626  */
627 STATIC int					/* error */
628 xfs_bmap_extents_to_btree(
629 	struct xfs_trans	*tp,		/* transaction pointer */
630 	struct xfs_inode	*ip,		/* incore inode pointer */
631 	struct xfs_btree_cur	**curp,		/* cursor returned to caller */
632 	int			wasdel,		/* converting a delayed alloc */
633 	int			*logflagsp,	/* inode logging flags */
634 	int			whichfork)	/* data or attr fork */
635 {
636 	struct xfs_btree_block	*ablock;	/* allocated (child) bt block */
637 	struct xfs_buf		*abp;		/* buffer for ablock */
638 	struct xfs_alloc_arg	args;		/* allocation arguments */
639 	struct xfs_bmbt_rec	*arp;		/* child record pointer */
640 	struct xfs_btree_block	*block;		/* btree root block */
641 	struct xfs_btree_cur	*cur;		/* bmap btree cursor */
642 	int			error;		/* error return value */
643 	struct xfs_ifork	*ifp;		/* inode fork pointer */
644 	struct xfs_bmbt_key	*kp;		/* root block key pointer */
645 	struct xfs_mount	*mp;		/* mount structure */
646 	xfs_bmbt_ptr_t		*pp;		/* root block address pointer */
647 	struct xfs_iext_cursor	icur;
648 	struct xfs_bmbt_irec	rec;
649 	xfs_extnum_t		cnt = 0;
650 
651 	mp = ip->i_mount;
652 	ASSERT(whichfork != XFS_COW_FORK);
653 	ifp = xfs_ifork_ptr(ip, whichfork);
654 	ASSERT(ifp->if_format == XFS_DINODE_FMT_EXTENTS);
655 
656 	/*
657 	 * Make space in the inode incore. This needs to be undone if we fail
658 	 * to expand the root.
659 	 */
660 	xfs_iroot_realloc(ip, 1, whichfork);
661 
662 	/*
663 	 * Fill in the root.
664 	 */
665 	block = ifp->if_broot;
666 	xfs_bmbt_init_block(ip, block, NULL, 1, 1);
667 	/*
668 	 * Need a cursor.  Can't allocate until bb_level is filled in.
669 	 */
670 	cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
671 	if (wasdel)
672 		cur->bc_flags |= XFS_BTREE_BMBT_WASDEL;
673 	/*
674 	 * Convert to a btree with two levels, one record in root.
675 	 */
676 	ifp->if_format = XFS_DINODE_FMT_BTREE;
677 	memset(&args, 0, sizeof(args));
678 	args.tp = tp;
679 	args.mp = mp;
680 	xfs_rmap_ino_bmbt_owner(&args.oinfo, ip->i_ino, whichfork);
681 
682 	args.minlen = args.maxlen = args.prod = 1;
683 	args.wasdel = wasdel;
684 	*logflagsp = 0;
685 	error = xfs_alloc_vextent_start_ag(&args,
686 				XFS_INO_TO_FSB(mp, ip->i_ino));
687 	if (error)
688 		goto out_root_realloc;
689 
690 	/*
691 	 * Allocation can't fail, the space was reserved.
692 	 */
693 	if (WARN_ON_ONCE(args.fsbno == NULLFSBLOCK)) {
694 		error = -ENOSPC;
695 		goto out_root_realloc;
696 	}
697 
698 	cur->bc_bmap.allocated++;
699 	ip->i_nblocks++;
700 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, 1L);
701 	error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
702 			XFS_FSB_TO_DADDR(mp, args.fsbno),
703 			mp->m_bsize, 0, &abp);
704 	if (error)
705 		goto out_unreserve_dquot;
706 
707 	/*
708 	 * Fill in the child block.
709 	 */
710 	ablock = XFS_BUF_TO_BLOCK(abp);
711 	xfs_bmbt_init_block(ip, ablock, abp, 0, 0);
712 
713 	for_each_xfs_iext(ifp, &icur, &rec) {
714 		if (isnullstartblock(rec.br_startblock))
715 			continue;
716 		arp = XFS_BMBT_REC_ADDR(mp, ablock, 1 + cnt);
717 		xfs_bmbt_disk_set_all(arp, &rec);
718 		cnt++;
719 	}
720 	ASSERT(cnt == ifp->if_nextents);
721 	xfs_btree_set_numrecs(ablock, cnt);
722 
723 	/*
724 	 * Fill in the root key and pointer.
725 	 */
726 	kp = XFS_BMBT_KEY_ADDR(mp, block, 1);
727 	arp = XFS_BMBT_REC_ADDR(mp, ablock, 1);
728 	kp->br_startoff = cpu_to_be64(xfs_bmbt_disk_get_startoff(arp));
729 	pp = XFS_BMBT_PTR_ADDR(mp, block, 1, xfs_bmbt_get_maxrecs(cur,
730 						be16_to_cpu(block->bb_level)));
731 	*pp = cpu_to_be64(args.fsbno);
732 
733 	/*
734 	 * Do all this logging at the end so that
735 	 * the root is at the right level.
736 	 */
737 	xfs_btree_log_block(cur, abp, XFS_BB_ALL_BITS);
738 	xfs_btree_log_recs(cur, abp, 1, be16_to_cpu(ablock->bb_numrecs));
739 	ASSERT(*curp == NULL);
740 	*curp = cur;
741 	*logflagsp = XFS_ILOG_CORE | xfs_ilog_fbroot(whichfork);
742 	return 0;
743 
744 out_unreserve_dquot:
745 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
746 out_root_realloc:
747 	xfs_iroot_realloc(ip, -1, whichfork);
748 	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
749 	ASSERT(ifp->if_broot == NULL);
750 	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
751 
752 	return error;
753 }
754 
755 /*
756  * Convert a local file to an extents file.
757  * This code is out of bounds for data forks of regular files,
758  * since the file data needs to get logged so things will stay consistent.
759  * (The bmap-level manipulations are ok, though).
760  */
761 void
762 xfs_bmap_local_to_extents_empty(
763 	struct xfs_trans	*tp,
764 	struct xfs_inode	*ip,
765 	int			whichfork)
766 {
767 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
768 
769 	ASSERT(whichfork != XFS_COW_FORK);
770 	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
771 	ASSERT(ifp->if_bytes == 0);
772 	ASSERT(ifp->if_nextents == 0);
773 
774 	xfs_bmap_forkoff_reset(ip, whichfork);
775 	ifp->if_data = NULL;
776 	ifp->if_height = 0;
777 	ifp->if_format = XFS_DINODE_FMT_EXTENTS;
778 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
779 }
780 
781 
782 STATIC int				/* error */
783 xfs_bmap_local_to_extents(
784 	xfs_trans_t	*tp,		/* transaction pointer */
785 	xfs_inode_t	*ip,		/* incore inode pointer */
786 	xfs_extlen_t	total,		/* total blocks needed by transaction */
787 	int		*logflagsp,	/* inode logging flags */
788 	int		whichfork,
789 	void		(*init_fn)(struct xfs_trans *tp,
790 				   struct xfs_buf *bp,
791 				   struct xfs_inode *ip,
792 				   struct xfs_ifork *ifp))
793 {
794 	int		error = 0;
795 	int		flags;		/* logging flags returned */
796 	struct xfs_ifork *ifp;		/* inode fork pointer */
797 	xfs_alloc_arg_t	args;		/* allocation arguments */
798 	struct xfs_buf	*bp;		/* buffer for extent block */
799 	struct xfs_bmbt_irec rec;
800 	struct xfs_iext_cursor icur;
801 
802 	/*
803 	 * We don't want to deal with the case of keeping inode data inline yet.
804 	 * So sending the data fork of a regular inode is invalid.
805 	 */
806 	ASSERT(!(S_ISREG(VFS_I(ip)->i_mode) && whichfork == XFS_DATA_FORK));
807 	ifp = xfs_ifork_ptr(ip, whichfork);
808 	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
809 
810 	if (!ifp->if_bytes) {
811 		xfs_bmap_local_to_extents_empty(tp, ip, whichfork);
812 		flags = XFS_ILOG_CORE;
813 		goto done;
814 	}
815 
816 	flags = 0;
817 	error = 0;
818 	memset(&args, 0, sizeof(args));
819 	args.tp = tp;
820 	args.mp = ip->i_mount;
821 	args.total = total;
822 	args.minlen = args.maxlen = args.prod = 1;
823 	xfs_rmap_ino_owner(&args.oinfo, ip->i_ino, whichfork, 0);
824 
825 	/*
826 	 * Allocate a block.  We know we need only one, since the
827 	 * file currently fits in an inode.
828 	 */
829 	args.total = total;
830 	args.minlen = args.maxlen = args.prod = 1;
831 	error = xfs_alloc_vextent_start_ag(&args,
832 			XFS_INO_TO_FSB(args.mp, ip->i_ino));
833 	if (error)
834 		goto done;
835 
836 	/* Can't fail, the space was reserved. */
837 	ASSERT(args.fsbno != NULLFSBLOCK);
838 	ASSERT(args.len == 1);
839 	error = xfs_trans_get_buf(tp, args.mp->m_ddev_targp,
840 			XFS_FSB_TO_DADDR(args.mp, args.fsbno),
841 			args.mp->m_bsize, 0, &bp);
842 	if (error)
843 		goto done;
844 
845 	/*
846 	 * Initialize the block, copy the data and log the remote buffer.
847 	 *
848 	 * The callout is responsible for logging because the remote format
849 	 * might differ from the local format and thus we don't know how much to
850 	 * log here. Note that init_fn must also set the buffer log item type
851 	 * correctly.
852 	 */
853 	init_fn(tp, bp, ip, ifp);
854 
855 	/* account for the change in fork size */
856 	xfs_idata_realloc(ip, -ifp->if_bytes, whichfork);
857 	xfs_bmap_local_to_extents_empty(tp, ip, whichfork);
858 	flags |= XFS_ILOG_CORE;
859 
860 	ifp->if_data = NULL;
861 	ifp->if_height = 0;
862 
863 	rec.br_startoff = 0;
864 	rec.br_startblock = args.fsbno;
865 	rec.br_blockcount = 1;
866 	rec.br_state = XFS_EXT_NORM;
867 	xfs_iext_first(ifp, &icur);
868 	xfs_iext_insert(ip, &icur, &rec, 0);
869 
870 	ifp->if_nextents = 1;
871 	ip->i_nblocks = 1;
872 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, 1L);
873 	flags |= xfs_ilog_fext(whichfork);
874 
875 done:
876 	*logflagsp = flags;
877 	return error;
878 }
879 
880 /*
881  * Called from xfs_bmap_add_attrfork to handle btree format files.
882  */
883 STATIC int					/* error */
884 xfs_bmap_add_attrfork_btree(
885 	xfs_trans_t		*tp,		/* transaction pointer */
886 	xfs_inode_t		*ip,		/* incore inode pointer */
887 	int			*flags)		/* inode logging flags */
888 {
889 	struct xfs_btree_block	*block = ip->i_df.if_broot;
890 	struct xfs_btree_cur	*cur;		/* btree cursor */
891 	int			error;		/* error return value */
892 	xfs_mount_t		*mp;		/* file system mount struct */
893 	int			stat;		/* newroot status */
894 
895 	mp = ip->i_mount;
896 
897 	if (XFS_BMAP_BMDR_SPACE(block) <= xfs_inode_data_fork_size(ip))
898 		*flags |= XFS_ILOG_DBROOT;
899 	else {
900 		cur = xfs_bmbt_init_cursor(mp, tp, ip, XFS_DATA_FORK);
901 		error = xfs_bmbt_lookup_first(cur, &stat);
902 		if (error)
903 			goto error0;
904 		/* must be at least one entry */
905 		if (XFS_IS_CORRUPT(mp, stat != 1)) {
906 			xfs_btree_mark_sick(cur);
907 			error = -EFSCORRUPTED;
908 			goto error0;
909 		}
910 		if ((error = xfs_btree_new_iroot(cur, flags, &stat)))
911 			goto error0;
912 		if (stat == 0) {
913 			xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
914 			return -ENOSPC;
915 		}
916 		cur->bc_bmap.allocated = 0;
917 		xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
918 	}
919 	return 0;
920 error0:
921 	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
922 	return error;
923 }
924 
925 /*
926  * Called from xfs_bmap_add_attrfork to handle extents format files.
927  */
928 STATIC int					/* error */
929 xfs_bmap_add_attrfork_extents(
930 	struct xfs_trans	*tp,		/* transaction pointer */
931 	struct xfs_inode	*ip,		/* incore inode pointer */
932 	int			*flags)		/* inode logging flags */
933 {
934 	struct xfs_btree_cur	*cur;		/* bmap btree cursor */
935 	int			error;		/* error return value */
936 
937 	if (ip->i_df.if_nextents * sizeof(struct xfs_bmbt_rec) <=
938 	    xfs_inode_data_fork_size(ip))
939 		return 0;
940 	cur = NULL;
941 	error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0, flags,
942 					  XFS_DATA_FORK);
943 	if (cur) {
944 		cur->bc_bmap.allocated = 0;
945 		xfs_btree_del_cursor(cur, error);
946 	}
947 	return error;
948 }
949 
950 /*
951  * Called from xfs_bmap_add_attrfork to handle local format files. Each
952  * different data fork content type needs a different callout to do the
953  * conversion. Some are basic and only require special block initialisation
954  * callouts for the data formating, others (directories) are so specialised they
955  * handle everything themselves.
956  *
957  * XXX (dgc): investigate whether directory conversion can use the generic
958  * formatting callout. It should be possible - it's just a very complex
959  * formatter.
960  */
961 STATIC int					/* error */
962 xfs_bmap_add_attrfork_local(
963 	struct xfs_trans	*tp,		/* transaction pointer */
964 	struct xfs_inode	*ip,		/* incore inode pointer */
965 	int			*flags)		/* inode logging flags */
966 {
967 	struct xfs_da_args	dargs;		/* args for dir/attr code */
968 
969 	if (ip->i_df.if_bytes <= xfs_inode_data_fork_size(ip))
970 		return 0;
971 
972 	if (S_ISDIR(VFS_I(ip)->i_mode)) {
973 		memset(&dargs, 0, sizeof(dargs));
974 		dargs.geo = ip->i_mount->m_dir_geo;
975 		dargs.dp = ip;
976 		dargs.total = dargs.geo->fsbcount;
977 		dargs.whichfork = XFS_DATA_FORK;
978 		dargs.trans = tp;
979 		return xfs_dir2_sf_to_block(&dargs);
980 	}
981 
982 	if (S_ISLNK(VFS_I(ip)->i_mode))
983 		return xfs_bmap_local_to_extents(tp, ip, 1, flags,
984 						 XFS_DATA_FORK,
985 						 xfs_symlink_local_to_remote);
986 
987 	/* should only be called for types that support local format data */
988 	ASSERT(0);
989 	xfs_bmap_mark_sick(ip, XFS_ATTR_FORK);
990 	return -EFSCORRUPTED;
991 }
992 
993 /*
994  * Set an inode attr fork offset based on the format of the data fork.
995  */
996 static int
997 xfs_bmap_set_attrforkoff(
998 	struct xfs_inode	*ip,
999 	int			size,
1000 	int			*version)
1001 {
1002 	int			default_size = xfs_default_attroffset(ip) >> 3;
1003 
1004 	switch (ip->i_df.if_format) {
1005 	case XFS_DINODE_FMT_DEV:
1006 		ip->i_forkoff = default_size;
1007 		break;
1008 	case XFS_DINODE_FMT_LOCAL:
1009 	case XFS_DINODE_FMT_EXTENTS:
1010 	case XFS_DINODE_FMT_BTREE:
1011 		ip->i_forkoff = xfs_attr_shortform_bytesfit(ip, size);
1012 		if (!ip->i_forkoff)
1013 			ip->i_forkoff = default_size;
1014 		else if (xfs_has_attr2(ip->i_mount) && version)
1015 			*version = 2;
1016 		break;
1017 	default:
1018 		ASSERT(0);
1019 		return -EINVAL;
1020 	}
1021 
1022 	return 0;
1023 }
1024 
1025 /*
1026  * Convert inode from non-attributed to attributed.
1027  * Must not be in a transaction, ip must not be locked.
1028  */
1029 int						/* error code */
1030 xfs_bmap_add_attrfork(
1031 	xfs_inode_t		*ip,		/* incore inode pointer */
1032 	int			size,		/* space new attribute needs */
1033 	int			rsvd)		/* xact may use reserved blks */
1034 {
1035 	xfs_mount_t		*mp;		/* mount structure */
1036 	xfs_trans_t		*tp;		/* transaction pointer */
1037 	int			blks;		/* space reservation */
1038 	int			version = 1;	/* superblock attr version */
1039 	int			logflags;	/* logging flags */
1040 	int			error;		/* error return value */
1041 
1042 	ASSERT(xfs_inode_has_attr_fork(ip) == 0);
1043 
1044 	mp = ip->i_mount;
1045 	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1046 
1047 	blks = XFS_ADDAFORK_SPACE_RES(mp);
1048 
1049 	error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_addafork, blks, 0,
1050 			rsvd, &tp);
1051 	if (error)
1052 		return error;
1053 	if (xfs_inode_has_attr_fork(ip))
1054 		goto trans_cancel;
1055 
1056 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1057 	error = xfs_bmap_set_attrforkoff(ip, size, &version);
1058 	if (error)
1059 		goto trans_cancel;
1060 
1061 	xfs_ifork_init_attr(ip, XFS_DINODE_FMT_EXTENTS, 0);
1062 	logflags = 0;
1063 	switch (ip->i_df.if_format) {
1064 	case XFS_DINODE_FMT_LOCAL:
1065 		error = xfs_bmap_add_attrfork_local(tp, ip, &logflags);
1066 		break;
1067 	case XFS_DINODE_FMT_EXTENTS:
1068 		error = xfs_bmap_add_attrfork_extents(tp, ip, &logflags);
1069 		break;
1070 	case XFS_DINODE_FMT_BTREE:
1071 		error = xfs_bmap_add_attrfork_btree(tp, ip, &logflags);
1072 		break;
1073 	default:
1074 		error = 0;
1075 		break;
1076 	}
1077 	if (logflags)
1078 		xfs_trans_log_inode(tp, ip, logflags);
1079 	if (error)
1080 		goto trans_cancel;
1081 	if (!xfs_has_attr(mp) ||
1082 	   (!xfs_has_attr2(mp) && version == 2)) {
1083 		bool log_sb = false;
1084 
1085 		spin_lock(&mp->m_sb_lock);
1086 		if (!xfs_has_attr(mp)) {
1087 			xfs_add_attr(mp);
1088 			log_sb = true;
1089 		}
1090 		if (!xfs_has_attr2(mp) && version == 2) {
1091 			xfs_add_attr2(mp);
1092 			log_sb = true;
1093 		}
1094 		spin_unlock(&mp->m_sb_lock);
1095 		if (log_sb)
1096 			xfs_log_sb(tp);
1097 	}
1098 
1099 	error = xfs_trans_commit(tp);
1100 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1101 	return error;
1102 
1103 trans_cancel:
1104 	xfs_trans_cancel(tp);
1105 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1106 	return error;
1107 }
1108 
1109 /*
1110  * Internal and external extent tree search functions.
1111  */
1112 
1113 struct xfs_iread_state {
1114 	struct xfs_iext_cursor	icur;
1115 	xfs_extnum_t		loaded;
1116 };
1117 
1118 int
1119 xfs_bmap_complain_bad_rec(
1120 	struct xfs_inode		*ip,
1121 	int				whichfork,
1122 	xfs_failaddr_t			fa,
1123 	const struct xfs_bmbt_irec	*irec)
1124 {
1125 	struct xfs_mount		*mp = ip->i_mount;
1126 	const char			*forkname;
1127 
1128 	switch (whichfork) {
1129 	case XFS_DATA_FORK:	forkname = "data"; break;
1130 	case XFS_ATTR_FORK:	forkname = "attr"; break;
1131 	case XFS_COW_FORK:	forkname = "CoW"; break;
1132 	default:		forkname = "???"; break;
1133 	}
1134 
1135 	xfs_warn(mp,
1136  "Bmap BTree record corruption in inode 0x%llx %s fork detected at %pS!",
1137 				ip->i_ino, forkname, fa);
1138 	xfs_warn(mp,
1139 		"Offset 0x%llx, start block 0x%llx, block count 0x%llx state 0x%x",
1140 		irec->br_startoff, irec->br_startblock, irec->br_blockcount,
1141 		irec->br_state);
1142 
1143 	return -EFSCORRUPTED;
1144 }
1145 
1146 /* Stuff every bmbt record from this block into the incore extent map. */
1147 static int
1148 xfs_iread_bmbt_block(
1149 	struct xfs_btree_cur	*cur,
1150 	int			level,
1151 	void			*priv)
1152 {
1153 	struct xfs_iread_state	*ir = priv;
1154 	struct xfs_mount	*mp = cur->bc_mp;
1155 	struct xfs_inode	*ip = cur->bc_ino.ip;
1156 	struct xfs_btree_block	*block;
1157 	struct xfs_buf		*bp;
1158 	struct xfs_bmbt_rec	*frp;
1159 	xfs_extnum_t		num_recs;
1160 	xfs_extnum_t		j;
1161 	int			whichfork = cur->bc_ino.whichfork;
1162 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
1163 
1164 	block = xfs_btree_get_block(cur, level, &bp);
1165 
1166 	/* Abort if we find more records than nextents. */
1167 	num_recs = xfs_btree_get_numrecs(block);
1168 	if (unlikely(ir->loaded + num_recs > ifp->if_nextents)) {
1169 		xfs_warn(ip->i_mount, "corrupt dinode %llu, (btree extents).",
1170 				(unsigned long long)ip->i_ino);
1171 		xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__, block,
1172 				sizeof(*block), __this_address);
1173 		xfs_bmap_mark_sick(ip, whichfork);
1174 		return -EFSCORRUPTED;
1175 	}
1176 
1177 	/* Copy records into the incore cache. */
1178 	frp = XFS_BMBT_REC_ADDR(mp, block, 1);
1179 	for (j = 0; j < num_recs; j++, frp++, ir->loaded++) {
1180 		struct xfs_bmbt_irec	new;
1181 		xfs_failaddr_t		fa;
1182 
1183 		xfs_bmbt_disk_get_all(frp, &new);
1184 		fa = xfs_bmap_validate_extent(ip, whichfork, &new);
1185 		if (fa) {
1186 			xfs_inode_verifier_error(ip, -EFSCORRUPTED,
1187 					"xfs_iread_extents(2)", frp,
1188 					sizeof(*frp), fa);
1189 			xfs_bmap_mark_sick(ip, whichfork);
1190 			return xfs_bmap_complain_bad_rec(ip, whichfork, fa,
1191 					&new);
1192 		}
1193 		xfs_iext_insert(ip, &ir->icur, &new,
1194 				xfs_bmap_fork_to_state(whichfork));
1195 		trace_xfs_read_extent(ip, &ir->icur,
1196 				xfs_bmap_fork_to_state(whichfork), _THIS_IP_);
1197 		xfs_iext_next(ifp, &ir->icur);
1198 	}
1199 
1200 	return 0;
1201 }
1202 
1203 /*
1204  * Read in extents from a btree-format inode.
1205  */
1206 int
1207 xfs_iread_extents(
1208 	struct xfs_trans	*tp,
1209 	struct xfs_inode	*ip,
1210 	int			whichfork)
1211 {
1212 	struct xfs_iread_state	ir;
1213 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
1214 	struct xfs_mount	*mp = ip->i_mount;
1215 	struct xfs_btree_cur	*cur;
1216 	int			error;
1217 
1218 	if (!xfs_need_iread_extents(ifp))
1219 		return 0;
1220 
1221 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
1222 
1223 	ir.loaded = 0;
1224 	xfs_iext_first(ifp, &ir.icur);
1225 	cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
1226 	error = xfs_btree_visit_blocks(cur, xfs_iread_bmbt_block,
1227 			XFS_BTREE_VISIT_RECORDS, &ir);
1228 	xfs_btree_del_cursor(cur, error);
1229 	if (error)
1230 		goto out;
1231 
1232 	if (XFS_IS_CORRUPT(mp, ir.loaded != ifp->if_nextents)) {
1233 		xfs_bmap_mark_sick(ip, whichfork);
1234 		error = -EFSCORRUPTED;
1235 		goto out;
1236 	}
1237 	ASSERT(ir.loaded == xfs_iext_count(ifp));
1238 	/*
1239 	 * Use release semantics so that we can use acquire semantics in
1240 	 * xfs_need_iread_extents and be guaranteed to see a valid mapping tree
1241 	 * after that load.
1242 	 */
1243 	smp_store_release(&ifp->if_needextents, 0);
1244 	return 0;
1245 out:
1246 	if (xfs_metadata_is_sick(error))
1247 		xfs_bmap_mark_sick(ip, whichfork);
1248 	xfs_iext_destroy(ifp);
1249 	return error;
1250 }
1251 
1252 /*
1253  * Returns the relative block number of the first unused block(s) in the given
1254  * fork with at least "len" logically contiguous blocks free.  This is the
1255  * lowest-address hole if the fork has holes, else the first block past the end
1256  * of fork.  Return 0 if the fork is currently local (in-inode).
1257  */
1258 int						/* error */
1259 xfs_bmap_first_unused(
1260 	struct xfs_trans	*tp,		/* transaction pointer */
1261 	struct xfs_inode	*ip,		/* incore inode */
1262 	xfs_extlen_t		len,		/* size of hole to find */
1263 	xfs_fileoff_t		*first_unused,	/* unused block */
1264 	int			whichfork)	/* data or attr fork */
1265 {
1266 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
1267 	struct xfs_bmbt_irec	got;
1268 	struct xfs_iext_cursor	icur;
1269 	xfs_fileoff_t		lastaddr = 0;
1270 	xfs_fileoff_t		lowest, max;
1271 	int			error;
1272 
1273 	if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
1274 		*first_unused = 0;
1275 		return 0;
1276 	}
1277 
1278 	ASSERT(xfs_ifork_has_extents(ifp));
1279 
1280 	error = xfs_iread_extents(tp, ip, whichfork);
1281 	if (error)
1282 		return error;
1283 
1284 	lowest = max = *first_unused;
1285 	for_each_xfs_iext(ifp, &icur, &got) {
1286 		/*
1287 		 * See if the hole before this extent will work.
1288 		 */
1289 		if (got.br_startoff >= lowest + len &&
1290 		    got.br_startoff - max >= len)
1291 			break;
1292 		lastaddr = got.br_startoff + got.br_blockcount;
1293 		max = XFS_FILEOFF_MAX(lastaddr, lowest);
1294 	}
1295 
1296 	*first_unused = max;
1297 	return 0;
1298 }
1299 
1300 /*
1301  * Returns the file-relative block number of the last block - 1 before
1302  * last_block (input value) in the file.
1303  * This is not based on i_size, it is based on the extent records.
1304  * Returns 0 for local files, as they do not have extent records.
1305  */
1306 int						/* error */
1307 xfs_bmap_last_before(
1308 	struct xfs_trans	*tp,		/* transaction pointer */
1309 	struct xfs_inode	*ip,		/* incore inode */
1310 	xfs_fileoff_t		*last_block,	/* last block */
1311 	int			whichfork)	/* data or attr fork */
1312 {
1313 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
1314 	struct xfs_bmbt_irec	got;
1315 	struct xfs_iext_cursor	icur;
1316 	int			error;
1317 
1318 	switch (ifp->if_format) {
1319 	case XFS_DINODE_FMT_LOCAL:
1320 		*last_block = 0;
1321 		return 0;
1322 	case XFS_DINODE_FMT_BTREE:
1323 	case XFS_DINODE_FMT_EXTENTS:
1324 		break;
1325 	default:
1326 		ASSERT(0);
1327 		xfs_bmap_mark_sick(ip, whichfork);
1328 		return -EFSCORRUPTED;
1329 	}
1330 
1331 	error = xfs_iread_extents(tp, ip, whichfork);
1332 	if (error)
1333 		return error;
1334 
1335 	if (!xfs_iext_lookup_extent_before(ip, ifp, last_block, &icur, &got))
1336 		*last_block = 0;
1337 	return 0;
1338 }
1339 
1340 int
1341 xfs_bmap_last_extent(
1342 	struct xfs_trans	*tp,
1343 	struct xfs_inode	*ip,
1344 	int			whichfork,
1345 	struct xfs_bmbt_irec	*rec,
1346 	int			*is_empty)
1347 {
1348 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
1349 	struct xfs_iext_cursor	icur;
1350 	int			error;
1351 
1352 	error = xfs_iread_extents(tp, ip, whichfork);
1353 	if (error)
1354 		return error;
1355 
1356 	xfs_iext_last(ifp, &icur);
1357 	if (!xfs_iext_get_extent(ifp, &icur, rec))
1358 		*is_empty = 1;
1359 	else
1360 		*is_empty = 0;
1361 	return 0;
1362 }
1363 
1364 /*
1365  * Check the last inode extent to determine whether this allocation will result
1366  * in blocks being allocated at the end of the file. When we allocate new data
1367  * blocks at the end of the file which do not start at the previous data block,
1368  * we will try to align the new blocks at stripe unit boundaries.
1369  *
1370  * Returns 1 in bma->aeof if the file (fork) is empty as any new write will be
1371  * at, or past the EOF.
1372  */
1373 STATIC int
1374 xfs_bmap_isaeof(
1375 	struct xfs_bmalloca	*bma,
1376 	int			whichfork)
1377 {
1378 	struct xfs_bmbt_irec	rec;
1379 	int			is_empty;
1380 	int			error;
1381 
1382 	bma->aeof = false;
1383 	error = xfs_bmap_last_extent(NULL, bma->ip, whichfork, &rec,
1384 				     &is_empty);
1385 	if (error)
1386 		return error;
1387 
1388 	if (is_empty) {
1389 		bma->aeof = true;
1390 		return 0;
1391 	}
1392 
1393 	/*
1394 	 * Check if we are allocation or past the last extent, or at least into
1395 	 * the last delayed allocated extent.
1396 	 */
1397 	bma->aeof = bma->offset >= rec.br_startoff + rec.br_blockcount ||
1398 		(bma->offset >= rec.br_startoff &&
1399 		 isnullstartblock(rec.br_startblock));
1400 	return 0;
1401 }
1402 
1403 /*
1404  * Returns the file-relative block number of the first block past eof in
1405  * the file.  This is not based on i_size, it is based on the extent records.
1406  * Returns 0 for local files, as they do not have extent records.
1407  */
1408 int
1409 xfs_bmap_last_offset(
1410 	struct xfs_inode	*ip,
1411 	xfs_fileoff_t		*last_block,
1412 	int			whichfork)
1413 {
1414 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
1415 	struct xfs_bmbt_irec	rec;
1416 	int			is_empty;
1417 	int			error;
1418 
1419 	*last_block = 0;
1420 
1421 	if (ifp->if_format == XFS_DINODE_FMT_LOCAL)
1422 		return 0;
1423 
1424 	if (XFS_IS_CORRUPT(ip->i_mount, !xfs_ifork_has_extents(ifp))) {
1425 		xfs_bmap_mark_sick(ip, whichfork);
1426 		return -EFSCORRUPTED;
1427 	}
1428 
1429 	error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, &is_empty);
1430 	if (error || is_empty)
1431 		return error;
1432 
1433 	*last_block = rec.br_startoff + rec.br_blockcount;
1434 	return 0;
1435 }
1436 
1437 /*
1438  * Extent tree manipulation functions used during allocation.
1439  */
1440 
1441 /*
1442  * Convert a delayed allocation to a real allocation.
1443  */
1444 STATIC int				/* error */
1445 xfs_bmap_add_extent_delay_real(
1446 	struct xfs_bmalloca	*bma,
1447 	int			whichfork)
1448 {
1449 	struct xfs_mount	*mp = bma->ip->i_mount;
1450 	struct xfs_ifork	*ifp = xfs_ifork_ptr(bma->ip, whichfork);
1451 	struct xfs_bmbt_irec	*new = &bma->got;
1452 	int			error;	/* error return value */
1453 	int			i;	/* temp state */
1454 	xfs_fileoff_t		new_endoff;	/* end offset of new entry */
1455 	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
1456 					/* left is 0, right is 1, prev is 2 */
1457 	int			rval=0;	/* return value (logging flags) */
1458 	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
1459 	xfs_filblks_t		da_new; /* new count del alloc blocks used */
1460 	xfs_filblks_t		da_old; /* old count del alloc blocks used */
1461 	xfs_filblks_t		temp=0;	/* value for da_new calculations */
1462 	int			tmp_rval;	/* partial logging flags */
1463 	struct xfs_bmbt_irec	old;
1464 
1465 	ASSERT(whichfork != XFS_ATTR_FORK);
1466 	ASSERT(!isnullstartblock(new->br_startblock));
1467 	ASSERT(!bma->cur || (bma->cur->bc_flags & XFS_BTREE_BMBT_WASDEL));
1468 
1469 	XFS_STATS_INC(mp, xs_add_exlist);
1470 
1471 #define	LEFT		r[0]
1472 #define	RIGHT		r[1]
1473 #define	PREV		r[2]
1474 
1475 	/*
1476 	 * Set up a bunch of variables to make the tests simpler.
1477 	 */
1478 	xfs_iext_get_extent(ifp, &bma->icur, &PREV);
1479 	new_endoff = new->br_startoff + new->br_blockcount;
1480 	ASSERT(isnullstartblock(PREV.br_startblock));
1481 	ASSERT(PREV.br_startoff <= new->br_startoff);
1482 	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
1483 
1484 	da_old = startblockval(PREV.br_startblock);
1485 	da_new = 0;
1486 
1487 	/*
1488 	 * Set flags determining what part of the previous delayed allocation
1489 	 * extent is being replaced by a real allocation.
1490 	 */
1491 	if (PREV.br_startoff == new->br_startoff)
1492 		state |= BMAP_LEFT_FILLING;
1493 	if (PREV.br_startoff + PREV.br_blockcount == new_endoff)
1494 		state |= BMAP_RIGHT_FILLING;
1495 
1496 	/*
1497 	 * Check and set flags if this segment has a left neighbor.
1498 	 * Don't set contiguous if the combined extent would be too large.
1499 	 */
1500 	if (xfs_iext_peek_prev_extent(ifp, &bma->icur, &LEFT)) {
1501 		state |= BMAP_LEFT_VALID;
1502 		if (isnullstartblock(LEFT.br_startblock))
1503 			state |= BMAP_LEFT_DELAY;
1504 	}
1505 
1506 	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
1507 	    LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
1508 	    LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
1509 	    LEFT.br_state == new->br_state &&
1510 	    LEFT.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
1511 		state |= BMAP_LEFT_CONTIG;
1512 
1513 	/*
1514 	 * Check and set flags if this segment has a right neighbor.
1515 	 * Don't set contiguous if the combined extent would be too large.
1516 	 * Also check for all-three-contiguous being too large.
1517 	 */
1518 	if (xfs_iext_peek_next_extent(ifp, &bma->icur, &RIGHT)) {
1519 		state |= BMAP_RIGHT_VALID;
1520 		if (isnullstartblock(RIGHT.br_startblock))
1521 			state |= BMAP_RIGHT_DELAY;
1522 	}
1523 
1524 	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
1525 	    new_endoff == RIGHT.br_startoff &&
1526 	    new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
1527 	    new->br_state == RIGHT.br_state &&
1528 	    new->br_blockcount + RIGHT.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
1529 	    ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
1530 		       BMAP_RIGHT_FILLING)) !=
1531 		      (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
1532 		       BMAP_RIGHT_FILLING) ||
1533 	     LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
1534 			<= XFS_MAX_BMBT_EXTLEN))
1535 		state |= BMAP_RIGHT_CONTIG;
1536 
1537 	error = 0;
1538 	/*
1539 	 * Switch out based on the FILLING and CONTIG state bits.
1540 	 */
1541 	switch (state & (BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
1542 			 BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG)) {
1543 	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
1544 	     BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1545 		/*
1546 		 * Filling in all of a previously delayed allocation extent.
1547 		 * The left and right neighbors are both contiguous with new.
1548 		 */
1549 		LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
1550 
1551 		xfs_iext_remove(bma->ip, &bma->icur, state);
1552 		xfs_iext_remove(bma->ip, &bma->icur, state);
1553 		xfs_iext_prev(ifp, &bma->icur);
1554 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1555 		ifp->if_nextents--;
1556 
1557 		if (bma->cur == NULL)
1558 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1559 		else {
1560 			rval = XFS_ILOG_CORE;
1561 			error = xfs_bmbt_lookup_eq(bma->cur, &RIGHT, &i);
1562 			if (error)
1563 				goto done;
1564 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1565 				xfs_btree_mark_sick(bma->cur);
1566 				error = -EFSCORRUPTED;
1567 				goto done;
1568 			}
1569 			error = xfs_btree_delete(bma->cur, &i);
1570 			if (error)
1571 				goto done;
1572 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1573 				xfs_btree_mark_sick(bma->cur);
1574 				error = -EFSCORRUPTED;
1575 				goto done;
1576 			}
1577 			error = xfs_btree_decrement(bma->cur, 0, &i);
1578 			if (error)
1579 				goto done;
1580 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1581 				xfs_btree_mark_sick(bma->cur);
1582 				error = -EFSCORRUPTED;
1583 				goto done;
1584 			}
1585 			error = xfs_bmbt_update(bma->cur, &LEFT);
1586 			if (error)
1587 				goto done;
1588 		}
1589 		break;
1590 
1591 	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
1592 		/*
1593 		 * Filling in all of a previously delayed allocation extent.
1594 		 * The left neighbor is contiguous, the right is not.
1595 		 */
1596 		old = LEFT;
1597 		LEFT.br_blockcount += PREV.br_blockcount;
1598 
1599 		xfs_iext_remove(bma->ip, &bma->icur, state);
1600 		xfs_iext_prev(ifp, &bma->icur);
1601 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1602 
1603 		if (bma->cur == NULL)
1604 			rval = XFS_ILOG_DEXT;
1605 		else {
1606 			rval = 0;
1607 			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1608 			if (error)
1609 				goto done;
1610 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1611 				xfs_btree_mark_sick(bma->cur);
1612 				error = -EFSCORRUPTED;
1613 				goto done;
1614 			}
1615 			error = xfs_bmbt_update(bma->cur, &LEFT);
1616 			if (error)
1617 				goto done;
1618 		}
1619 		break;
1620 
1621 	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1622 		/*
1623 		 * Filling in all of a previously delayed allocation extent.
1624 		 * The right neighbor is contiguous, the left is not. Take care
1625 		 * with delay -> unwritten extent allocation here because the
1626 		 * delalloc record we are overwriting is always written.
1627 		 */
1628 		PREV.br_startblock = new->br_startblock;
1629 		PREV.br_blockcount += RIGHT.br_blockcount;
1630 		PREV.br_state = new->br_state;
1631 
1632 		xfs_iext_next(ifp, &bma->icur);
1633 		xfs_iext_remove(bma->ip, &bma->icur, state);
1634 		xfs_iext_prev(ifp, &bma->icur);
1635 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1636 
1637 		if (bma->cur == NULL)
1638 			rval = XFS_ILOG_DEXT;
1639 		else {
1640 			rval = 0;
1641 			error = xfs_bmbt_lookup_eq(bma->cur, &RIGHT, &i);
1642 			if (error)
1643 				goto done;
1644 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1645 				xfs_btree_mark_sick(bma->cur);
1646 				error = -EFSCORRUPTED;
1647 				goto done;
1648 			}
1649 			error = xfs_bmbt_update(bma->cur, &PREV);
1650 			if (error)
1651 				goto done;
1652 		}
1653 		break;
1654 
1655 	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
1656 		/*
1657 		 * Filling in all of a previously delayed allocation extent.
1658 		 * Neither the left nor right neighbors are contiguous with
1659 		 * the new one.
1660 		 */
1661 		PREV.br_startblock = new->br_startblock;
1662 		PREV.br_state = new->br_state;
1663 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1664 		ifp->if_nextents++;
1665 
1666 		if (bma->cur == NULL)
1667 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1668 		else {
1669 			rval = XFS_ILOG_CORE;
1670 			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1671 			if (error)
1672 				goto done;
1673 			if (XFS_IS_CORRUPT(mp, i != 0)) {
1674 				xfs_btree_mark_sick(bma->cur);
1675 				error = -EFSCORRUPTED;
1676 				goto done;
1677 			}
1678 			error = xfs_btree_insert(bma->cur, &i);
1679 			if (error)
1680 				goto done;
1681 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1682 				xfs_btree_mark_sick(bma->cur);
1683 				error = -EFSCORRUPTED;
1684 				goto done;
1685 			}
1686 		}
1687 		break;
1688 
1689 	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG:
1690 		/*
1691 		 * Filling in the first part of a previous delayed allocation.
1692 		 * The left neighbor is contiguous.
1693 		 */
1694 		old = LEFT;
1695 		temp = PREV.br_blockcount - new->br_blockcount;
1696 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1697 				startblockval(PREV.br_startblock));
1698 
1699 		LEFT.br_blockcount += new->br_blockcount;
1700 
1701 		PREV.br_blockcount = temp;
1702 		PREV.br_startoff += new->br_blockcount;
1703 		PREV.br_startblock = nullstartblock(da_new);
1704 
1705 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1706 		xfs_iext_prev(ifp, &bma->icur);
1707 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1708 
1709 		if (bma->cur == NULL)
1710 			rval = XFS_ILOG_DEXT;
1711 		else {
1712 			rval = 0;
1713 			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1714 			if (error)
1715 				goto done;
1716 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1717 				xfs_btree_mark_sick(bma->cur);
1718 				error = -EFSCORRUPTED;
1719 				goto done;
1720 			}
1721 			error = xfs_bmbt_update(bma->cur, &LEFT);
1722 			if (error)
1723 				goto done;
1724 		}
1725 		break;
1726 
1727 	case BMAP_LEFT_FILLING:
1728 		/*
1729 		 * Filling in the first part of a previous delayed allocation.
1730 		 * The left neighbor is not contiguous.
1731 		 */
1732 		xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
1733 		ifp->if_nextents++;
1734 
1735 		if (bma->cur == NULL)
1736 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1737 		else {
1738 			rval = XFS_ILOG_CORE;
1739 			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1740 			if (error)
1741 				goto done;
1742 			if (XFS_IS_CORRUPT(mp, i != 0)) {
1743 				xfs_btree_mark_sick(bma->cur);
1744 				error = -EFSCORRUPTED;
1745 				goto done;
1746 			}
1747 			error = xfs_btree_insert(bma->cur, &i);
1748 			if (error)
1749 				goto done;
1750 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1751 				xfs_btree_mark_sick(bma->cur);
1752 				error = -EFSCORRUPTED;
1753 				goto done;
1754 			}
1755 		}
1756 
1757 		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1758 			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1759 					&bma->cur, 1, &tmp_rval, whichfork);
1760 			rval |= tmp_rval;
1761 			if (error)
1762 				goto done;
1763 		}
1764 
1765 		temp = PREV.br_blockcount - new->br_blockcount;
1766 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1767 			startblockval(PREV.br_startblock) -
1768 			(bma->cur ? bma->cur->bc_bmap.allocated : 0));
1769 
1770 		PREV.br_startoff = new_endoff;
1771 		PREV.br_blockcount = temp;
1772 		PREV.br_startblock = nullstartblock(da_new);
1773 		xfs_iext_next(ifp, &bma->icur);
1774 		xfs_iext_insert(bma->ip, &bma->icur, &PREV, state);
1775 		xfs_iext_prev(ifp, &bma->icur);
1776 		break;
1777 
1778 	case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1779 		/*
1780 		 * Filling in the last part of a previous delayed allocation.
1781 		 * The right neighbor is contiguous with the new allocation.
1782 		 */
1783 		old = RIGHT;
1784 		RIGHT.br_startoff = new->br_startoff;
1785 		RIGHT.br_startblock = new->br_startblock;
1786 		RIGHT.br_blockcount += new->br_blockcount;
1787 
1788 		if (bma->cur == NULL)
1789 			rval = XFS_ILOG_DEXT;
1790 		else {
1791 			rval = 0;
1792 			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1793 			if (error)
1794 				goto done;
1795 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1796 				xfs_btree_mark_sick(bma->cur);
1797 				error = -EFSCORRUPTED;
1798 				goto done;
1799 			}
1800 			error = xfs_bmbt_update(bma->cur, &RIGHT);
1801 			if (error)
1802 				goto done;
1803 		}
1804 
1805 		temp = PREV.br_blockcount - new->br_blockcount;
1806 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1807 			startblockval(PREV.br_startblock));
1808 
1809 		PREV.br_blockcount = temp;
1810 		PREV.br_startblock = nullstartblock(da_new);
1811 
1812 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1813 		xfs_iext_next(ifp, &bma->icur);
1814 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &RIGHT);
1815 		break;
1816 
1817 	case BMAP_RIGHT_FILLING:
1818 		/*
1819 		 * Filling in the last part of a previous delayed allocation.
1820 		 * The right neighbor is not contiguous.
1821 		 */
1822 		xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
1823 		ifp->if_nextents++;
1824 
1825 		if (bma->cur == NULL)
1826 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1827 		else {
1828 			rval = XFS_ILOG_CORE;
1829 			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1830 			if (error)
1831 				goto done;
1832 			if (XFS_IS_CORRUPT(mp, i != 0)) {
1833 				xfs_btree_mark_sick(bma->cur);
1834 				error = -EFSCORRUPTED;
1835 				goto done;
1836 			}
1837 			error = xfs_btree_insert(bma->cur, &i);
1838 			if (error)
1839 				goto done;
1840 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1841 				xfs_btree_mark_sick(bma->cur);
1842 				error = -EFSCORRUPTED;
1843 				goto done;
1844 			}
1845 		}
1846 
1847 		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1848 			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1849 				&bma->cur, 1, &tmp_rval, whichfork);
1850 			rval |= tmp_rval;
1851 			if (error)
1852 				goto done;
1853 		}
1854 
1855 		temp = PREV.br_blockcount - new->br_blockcount;
1856 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1857 			startblockval(PREV.br_startblock) -
1858 			(bma->cur ? bma->cur->bc_bmap.allocated : 0));
1859 
1860 		PREV.br_startblock = nullstartblock(da_new);
1861 		PREV.br_blockcount = temp;
1862 		xfs_iext_insert(bma->ip, &bma->icur, &PREV, state);
1863 		xfs_iext_next(ifp, &bma->icur);
1864 		break;
1865 
1866 	case 0:
1867 		/*
1868 		 * Filling in the middle part of a previous delayed allocation.
1869 		 * Contiguity is impossible here.
1870 		 * This case is avoided almost all the time.
1871 		 *
1872 		 * We start with a delayed allocation:
1873 		 *
1874 		 * +ddddddddddddddddddddddddddddddddddddddddddddddddddddddd+
1875 		 *  PREV @ idx
1876 		 *
1877 	         * and we are allocating:
1878 		 *                     +rrrrrrrrrrrrrrrrr+
1879 		 *			      new
1880 		 *
1881 		 * and we set it up for insertion as:
1882 		 * +ddddddddddddddddddd+rrrrrrrrrrrrrrrrr+ddddddddddddddddd+
1883 		 *                            new
1884 		 *  PREV @ idx          LEFT              RIGHT
1885 		 *                      inserted at idx + 1
1886 		 */
1887 		old = PREV;
1888 
1889 		/* LEFT is the new middle */
1890 		LEFT = *new;
1891 
1892 		/* RIGHT is the new right */
1893 		RIGHT.br_state = PREV.br_state;
1894 		RIGHT.br_startoff = new_endoff;
1895 		RIGHT.br_blockcount =
1896 			PREV.br_startoff + PREV.br_blockcount - new_endoff;
1897 		RIGHT.br_startblock =
1898 			nullstartblock(xfs_bmap_worst_indlen(bma->ip,
1899 					RIGHT.br_blockcount));
1900 
1901 		/* truncate PREV */
1902 		PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
1903 		PREV.br_startblock =
1904 			nullstartblock(xfs_bmap_worst_indlen(bma->ip,
1905 					PREV.br_blockcount));
1906 		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1907 
1908 		xfs_iext_next(ifp, &bma->icur);
1909 		xfs_iext_insert(bma->ip, &bma->icur, &RIGHT, state);
1910 		xfs_iext_insert(bma->ip, &bma->icur, &LEFT, state);
1911 		ifp->if_nextents++;
1912 
1913 		if (bma->cur == NULL)
1914 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1915 		else {
1916 			rval = XFS_ILOG_CORE;
1917 			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1918 			if (error)
1919 				goto done;
1920 			if (XFS_IS_CORRUPT(mp, i != 0)) {
1921 				xfs_btree_mark_sick(bma->cur);
1922 				error = -EFSCORRUPTED;
1923 				goto done;
1924 			}
1925 			error = xfs_btree_insert(bma->cur, &i);
1926 			if (error)
1927 				goto done;
1928 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1929 				xfs_btree_mark_sick(bma->cur);
1930 				error = -EFSCORRUPTED;
1931 				goto done;
1932 			}
1933 		}
1934 
1935 		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1936 			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1937 					&bma->cur, 1, &tmp_rval, whichfork);
1938 			rval |= tmp_rval;
1939 			if (error)
1940 				goto done;
1941 		}
1942 
1943 		da_new = startblockval(PREV.br_startblock) +
1944 			 startblockval(RIGHT.br_startblock);
1945 		break;
1946 
1947 	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1948 	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1949 	case BMAP_LEFT_FILLING | BMAP_RIGHT_CONTIG:
1950 	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
1951 	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1952 	case BMAP_LEFT_CONTIG:
1953 	case BMAP_RIGHT_CONTIG:
1954 		/*
1955 		 * These cases are all impossible.
1956 		 */
1957 		ASSERT(0);
1958 	}
1959 
1960 	/* add reverse mapping unless caller opted out */
1961 	if (!(bma->flags & XFS_BMAPI_NORMAP))
1962 		xfs_rmap_map_extent(bma->tp, bma->ip, whichfork, new);
1963 
1964 	/* convert to a btree if necessary */
1965 	if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1966 		int	tmp_logflags;	/* partial log flag return val */
1967 
1968 		ASSERT(bma->cur == NULL);
1969 		error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1970 				&bma->cur, da_old > 0, &tmp_logflags,
1971 				whichfork);
1972 		bma->logflags |= tmp_logflags;
1973 		if (error)
1974 			goto done;
1975 	}
1976 
1977 	if (da_new != da_old)
1978 		xfs_mod_delalloc(mp, (int64_t)da_new - da_old);
1979 
1980 	if (bma->cur) {
1981 		da_new += bma->cur->bc_bmap.allocated;
1982 		bma->cur->bc_bmap.allocated = 0;
1983 	}
1984 
1985 	/* adjust for changes in reserved delayed indirect blocks */
1986 	if (da_new != da_old) {
1987 		ASSERT(state == 0 || da_new < da_old);
1988 		error = xfs_mod_fdblocks(mp, (int64_t)(da_old - da_new),
1989 				false);
1990 	}
1991 
1992 	xfs_bmap_check_leaf_extents(bma->cur, bma->ip, whichfork);
1993 done:
1994 	if (whichfork != XFS_COW_FORK)
1995 		bma->logflags |= rval;
1996 	return error;
1997 #undef	LEFT
1998 #undef	RIGHT
1999 #undef	PREV
2000 }
2001 
2002 /*
2003  * Convert an unwritten allocation to a real allocation or vice versa.
2004  */
2005 int					/* error */
2006 xfs_bmap_add_extent_unwritten_real(
2007 	struct xfs_trans	*tp,
2008 	xfs_inode_t		*ip,	/* incore inode pointer */
2009 	int			whichfork,
2010 	struct xfs_iext_cursor	*icur,
2011 	struct xfs_btree_cur	**curp,	/* if *curp is null, not a btree */
2012 	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
2013 	int			*logflagsp) /* inode logging flags */
2014 {
2015 	struct xfs_btree_cur	*cur;	/* btree cursor */
2016 	int			error;	/* error return value */
2017 	int			i;	/* temp state */
2018 	struct xfs_ifork	*ifp;	/* inode fork pointer */
2019 	xfs_fileoff_t		new_endoff;	/* end offset of new entry */
2020 	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
2021 					/* left is 0, right is 1, prev is 2 */
2022 	int			rval=0;	/* return value (logging flags) */
2023 	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
2024 	struct xfs_mount	*mp = ip->i_mount;
2025 	struct xfs_bmbt_irec	old;
2026 
2027 	*logflagsp = 0;
2028 
2029 	cur = *curp;
2030 	ifp = xfs_ifork_ptr(ip, whichfork);
2031 
2032 	ASSERT(!isnullstartblock(new->br_startblock));
2033 
2034 	XFS_STATS_INC(mp, xs_add_exlist);
2035 
2036 #define	LEFT		r[0]
2037 #define	RIGHT		r[1]
2038 #define	PREV		r[2]
2039 
2040 	/*
2041 	 * Set up a bunch of variables to make the tests simpler.
2042 	 */
2043 	error = 0;
2044 	xfs_iext_get_extent(ifp, icur, &PREV);
2045 	ASSERT(new->br_state != PREV.br_state);
2046 	new_endoff = new->br_startoff + new->br_blockcount;
2047 	ASSERT(PREV.br_startoff <= new->br_startoff);
2048 	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
2049 
2050 	/*
2051 	 * Set flags determining what part of the previous oldext allocation
2052 	 * extent is being replaced by a newext allocation.
2053 	 */
2054 	if (PREV.br_startoff == new->br_startoff)
2055 		state |= BMAP_LEFT_FILLING;
2056 	if (PREV.br_startoff + PREV.br_blockcount == new_endoff)
2057 		state |= BMAP_RIGHT_FILLING;
2058 
2059 	/*
2060 	 * Check and set flags if this segment has a left neighbor.
2061 	 * Don't set contiguous if the combined extent would be too large.
2062 	 */
2063 	if (xfs_iext_peek_prev_extent(ifp, icur, &LEFT)) {
2064 		state |= BMAP_LEFT_VALID;
2065 		if (isnullstartblock(LEFT.br_startblock))
2066 			state |= BMAP_LEFT_DELAY;
2067 	}
2068 
2069 	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
2070 	    LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
2071 	    LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
2072 	    LEFT.br_state == new->br_state &&
2073 	    LEFT.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2074 		state |= BMAP_LEFT_CONTIG;
2075 
2076 	/*
2077 	 * Check and set flags if this segment has a right neighbor.
2078 	 * Don't set contiguous if the combined extent would be too large.
2079 	 * Also check for all-three-contiguous being too large.
2080 	 */
2081 	if (xfs_iext_peek_next_extent(ifp, icur, &RIGHT)) {
2082 		state |= BMAP_RIGHT_VALID;
2083 		if (isnullstartblock(RIGHT.br_startblock))
2084 			state |= BMAP_RIGHT_DELAY;
2085 	}
2086 
2087 	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
2088 	    new_endoff == RIGHT.br_startoff &&
2089 	    new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
2090 	    new->br_state == RIGHT.br_state &&
2091 	    new->br_blockcount + RIGHT.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2092 	    ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
2093 		       BMAP_RIGHT_FILLING)) !=
2094 		      (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
2095 		       BMAP_RIGHT_FILLING) ||
2096 	     LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
2097 			<= XFS_MAX_BMBT_EXTLEN))
2098 		state |= BMAP_RIGHT_CONTIG;
2099 
2100 	/*
2101 	 * Switch out based on the FILLING and CONTIG state bits.
2102 	 */
2103 	switch (state & (BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
2104 			 BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG)) {
2105 	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
2106 	     BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2107 		/*
2108 		 * Setting all of a previous oldext extent to newext.
2109 		 * The left and right neighbors are both contiguous with new.
2110 		 */
2111 		LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
2112 
2113 		xfs_iext_remove(ip, icur, state);
2114 		xfs_iext_remove(ip, icur, state);
2115 		xfs_iext_prev(ifp, icur);
2116 		xfs_iext_update_extent(ip, state, icur, &LEFT);
2117 		ifp->if_nextents -= 2;
2118 		if (cur == NULL)
2119 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2120 		else {
2121 			rval = XFS_ILOG_CORE;
2122 			error = xfs_bmbt_lookup_eq(cur, &RIGHT, &i);
2123 			if (error)
2124 				goto done;
2125 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2126 				xfs_btree_mark_sick(cur);
2127 				error = -EFSCORRUPTED;
2128 				goto done;
2129 			}
2130 			if ((error = xfs_btree_delete(cur, &i)))
2131 				goto done;
2132 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2133 				xfs_btree_mark_sick(cur);
2134 				error = -EFSCORRUPTED;
2135 				goto done;
2136 			}
2137 			if ((error = xfs_btree_decrement(cur, 0, &i)))
2138 				goto done;
2139 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2140 				xfs_btree_mark_sick(cur);
2141 				error = -EFSCORRUPTED;
2142 				goto done;
2143 			}
2144 			if ((error = xfs_btree_delete(cur, &i)))
2145 				goto done;
2146 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2147 				xfs_btree_mark_sick(cur);
2148 				error = -EFSCORRUPTED;
2149 				goto done;
2150 			}
2151 			if ((error = xfs_btree_decrement(cur, 0, &i)))
2152 				goto done;
2153 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2154 				xfs_btree_mark_sick(cur);
2155 				error = -EFSCORRUPTED;
2156 				goto done;
2157 			}
2158 			error = xfs_bmbt_update(cur, &LEFT);
2159 			if (error)
2160 				goto done;
2161 		}
2162 		break;
2163 
2164 	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
2165 		/*
2166 		 * Setting all of a previous oldext extent to newext.
2167 		 * The left neighbor is contiguous, the right is not.
2168 		 */
2169 		LEFT.br_blockcount += PREV.br_blockcount;
2170 
2171 		xfs_iext_remove(ip, icur, state);
2172 		xfs_iext_prev(ifp, icur);
2173 		xfs_iext_update_extent(ip, state, icur, &LEFT);
2174 		ifp->if_nextents--;
2175 		if (cur == NULL)
2176 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2177 		else {
2178 			rval = XFS_ILOG_CORE;
2179 			error = xfs_bmbt_lookup_eq(cur, &PREV, &i);
2180 			if (error)
2181 				goto done;
2182 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2183 				xfs_btree_mark_sick(cur);
2184 				error = -EFSCORRUPTED;
2185 				goto done;
2186 			}
2187 			if ((error = xfs_btree_delete(cur, &i)))
2188 				goto done;
2189 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2190 				xfs_btree_mark_sick(cur);
2191 				error = -EFSCORRUPTED;
2192 				goto done;
2193 			}
2194 			if ((error = xfs_btree_decrement(cur, 0, &i)))
2195 				goto done;
2196 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2197 				xfs_btree_mark_sick(cur);
2198 				error = -EFSCORRUPTED;
2199 				goto done;
2200 			}
2201 			error = xfs_bmbt_update(cur, &LEFT);
2202 			if (error)
2203 				goto done;
2204 		}
2205 		break;
2206 
2207 	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2208 		/*
2209 		 * Setting all of a previous oldext extent to newext.
2210 		 * The right neighbor is contiguous, the left is not.
2211 		 */
2212 		PREV.br_blockcount += RIGHT.br_blockcount;
2213 		PREV.br_state = new->br_state;
2214 
2215 		xfs_iext_next(ifp, icur);
2216 		xfs_iext_remove(ip, icur, state);
2217 		xfs_iext_prev(ifp, icur);
2218 		xfs_iext_update_extent(ip, state, icur, &PREV);
2219 		ifp->if_nextents--;
2220 
2221 		if (cur == NULL)
2222 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2223 		else {
2224 			rval = XFS_ILOG_CORE;
2225 			error = xfs_bmbt_lookup_eq(cur, &RIGHT, &i);
2226 			if (error)
2227 				goto done;
2228 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2229 				xfs_btree_mark_sick(cur);
2230 				error = -EFSCORRUPTED;
2231 				goto done;
2232 			}
2233 			if ((error = xfs_btree_delete(cur, &i)))
2234 				goto done;
2235 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2236 				xfs_btree_mark_sick(cur);
2237 				error = -EFSCORRUPTED;
2238 				goto done;
2239 			}
2240 			if ((error = xfs_btree_decrement(cur, 0, &i)))
2241 				goto done;
2242 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2243 				xfs_btree_mark_sick(cur);
2244 				error = -EFSCORRUPTED;
2245 				goto done;
2246 			}
2247 			error = xfs_bmbt_update(cur, &PREV);
2248 			if (error)
2249 				goto done;
2250 		}
2251 		break;
2252 
2253 	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
2254 		/*
2255 		 * Setting all of a previous oldext extent to newext.
2256 		 * Neither the left nor right neighbors are contiguous with
2257 		 * the new one.
2258 		 */
2259 		PREV.br_state = new->br_state;
2260 		xfs_iext_update_extent(ip, state, icur, &PREV);
2261 
2262 		if (cur == NULL)
2263 			rval = XFS_ILOG_DEXT;
2264 		else {
2265 			rval = 0;
2266 			error = xfs_bmbt_lookup_eq(cur, new, &i);
2267 			if (error)
2268 				goto done;
2269 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2270 				xfs_btree_mark_sick(cur);
2271 				error = -EFSCORRUPTED;
2272 				goto done;
2273 			}
2274 			error = xfs_bmbt_update(cur, &PREV);
2275 			if (error)
2276 				goto done;
2277 		}
2278 		break;
2279 
2280 	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG:
2281 		/*
2282 		 * Setting the first part of a previous oldext extent to newext.
2283 		 * The left neighbor is contiguous.
2284 		 */
2285 		LEFT.br_blockcount += new->br_blockcount;
2286 
2287 		old = PREV;
2288 		PREV.br_startoff += new->br_blockcount;
2289 		PREV.br_startblock += new->br_blockcount;
2290 		PREV.br_blockcount -= new->br_blockcount;
2291 
2292 		xfs_iext_update_extent(ip, state, icur, &PREV);
2293 		xfs_iext_prev(ifp, icur);
2294 		xfs_iext_update_extent(ip, state, icur, &LEFT);
2295 
2296 		if (cur == NULL)
2297 			rval = XFS_ILOG_DEXT;
2298 		else {
2299 			rval = 0;
2300 			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2301 			if (error)
2302 				goto done;
2303 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2304 				xfs_btree_mark_sick(cur);
2305 				error = -EFSCORRUPTED;
2306 				goto done;
2307 			}
2308 			error = xfs_bmbt_update(cur, &PREV);
2309 			if (error)
2310 				goto done;
2311 			error = xfs_btree_decrement(cur, 0, &i);
2312 			if (error)
2313 				goto done;
2314 			error = xfs_bmbt_update(cur, &LEFT);
2315 			if (error)
2316 				goto done;
2317 		}
2318 		break;
2319 
2320 	case BMAP_LEFT_FILLING:
2321 		/*
2322 		 * Setting the first part of a previous oldext extent to newext.
2323 		 * The left neighbor is not contiguous.
2324 		 */
2325 		old = PREV;
2326 		PREV.br_startoff += new->br_blockcount;
2327 		PREV.br_startblock += new->br_blockcount;
2328 		PREV.br_blockcount -= new->br_blockcount;
2329 
2330 		xfs_iext_update_extent(ip, state, icur, &PREV);
2331 		xfs_iext_insert(ip, icur, new, state);
2332 		ifp->if_nextents++;
2333 
2334 		if (cur == NULL)
2335 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2336 		else {
2337 			rval = XFS_ILOG_CORE;
2338 			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2339 			if (error)
2340 				goto done;
2341 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2342 				xfs_btree_mark_sick(cur);
2343 				error = -EFSCORRUPTED;
2344 				goto done;
2345 			}
2346 			error = xfs_bmbt_update(cur, &PREV);
2347 			if (error)
2348 				goto done;
2349 			cur->bc_rec.b = *new;
2350 			if ((error = xfs_btree_insert(cur, &i)))
2351 				goto done;
2352 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2353 				xfs_btree_mark_sick(cur);
2354 				error = -EFSCORRUPTED;
2355 				goto done;
2356 			}
2357 		}
2358 		break;
2359 
2360 	case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2361 		/*
2362 		 * Setting the last part of a previous oldext extent to newext.
2363 		 * The right neighbor is contiguous with the new allocation.
2364 		 */
2365 		old = PREV;
2366 		PREV.br_blockcount -= new->br_blockcount;
2367 
2368 		RIGHT.br_startoff = new->br_startoff;
2369 		RIGHT.br_startblock = new->br_startblock;
2370 		RIGHT.br_blockcount += new->br_blockcount;
2371 
2372 		xfs_iext_update_extent(ip, state, icur, &PREV);
2373 		xfs_iext_next(ifp, icur);
2374 		xfs_iext_update_extent(ip, state, icur, &RIGHT);
2375 
2376 		if (cur == NULL)
2377 			rval = XFS_ILOG_DEXT;
2378 		else {
2379 			rval = 0;
2380 			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2381 			if (error)
2382 				goto done;
2383 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2384 				xfs_btree_mark_sick(cur);
2385 				error = -EFSCORRUPTED;
2386 				goto done;
2387 			}
2388 			error = xfs_bmbt_update(cur, &PREV);
2389 			if (error)
2390 				goto done;
2391 			error = xfs_btree_increment(cur, 0, &i);
2392 			if (error)
2393 				goto done;
2394 			error = xfs_bmbt_update(cur, &RIGHT);
2395 			if (error)
2396 				goto done;
2397 		}
2398 		break;
2399 
2400 	case BMAP_RIGHT_FILLING:
2401 		/*
2402 		 * Setting the last part of a previous oldext extent to newext.
2403 		 * The right neighbor is not contiguous.
2404 		 */
2405 		old = PREV;
2406 		PREV.br_blockcount -= new->br_blockcount;
2407 
2408 		xfs_iext_update_extent(ip, state, icur, &PREV);
2409 		xfs_iext_next(ifp, icur);
2410 		xfs_iext_insert(ip, icur, new, state);
2411 		ifp->if_nextents++;
2412 
2413 		if (cur == NULL)
2414 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2415 		else {
2416 			rval = XFS_ILOG_CORE;
2417 			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2418 			if (error)
2419 				goto done;
2420 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2421 				xfs_btree_mark_sick(cur);
2422 				error = -EFSCORRUPTED;
2423 				goto done;
2424 			}
2425 			error = xfs_bmbt_update(cur, &PREV);
2426 			if (error)
2427 				goto done;
2428 			error = xfs_bmbt_lookup_eq(cur, new, &i);
2429 			if (error)
2430 				goto done;
2431 			if (XFS_IS_CORRUPT(mp, i != 0)) {
2432 				xfs_btree_mark_sick(cur);
2433 				error = -EFSCORRUPTED;
2434 				goto done;
2435 			}
2436 			if ((error = xfs_btree_insert(cur, &i)))
2437 				goto done;
2438 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2439 				xfs_btree_mark_sick(cur);
2440 				error = -EFSCORRUPTED;
2441 				goto done;
2442 			}
2443 		}
2444 		break;
2445 
2446 	case 0:
2447 		/*
2448 		 * Setting the middle part of a previous oldext extent to
2449 		 * newext.  Contiguity is impossible here.
2450 		 * One extent becomes three extents.
2451 		 */
2452 		old = PREV;
2453 		PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
2454 
2455 		r[0] = *new;
2456 		r[1].br_startoff = new_endoff;
2457 		r[1].br_blockcount =
2458 			old.br_startoff + old.br_blockcount - new_endoff;
2459 		r[1].br_startblock = new->br_startblock + new->br_blockcount;
2460 		r[1].br_state = PREV.br_state;
2461 
2462 		xfs_iext_update_extent(ip, state, icur, &PREV);
2463 		xfs_iext_next(ifp, icur);
2464 		xfs_iext_insert(ip, icur, &r[1], state);
2465 		xfs_iext_insert(ip, icur, &r[0], state);
2466 		ifp->if_nextents += 2;
2467 
2468 		if (cur == NULL)
2469 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2470 		else {
2471 			rval = XFS_ILOG_CORE;
2472 			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2473 			if (error)
2474 				goto done;
2475 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2476 				xfs_btree_mark_sick(cur);
2477 				error = -EFSCORRUPTED;
2478 				goto done;
2479 			}
2480 			/* new right extent - oldext */
2481 			error = xfs_bmbt_update(cur, &r[1]);
2482 			if (error)
2483 				goto done;
2484 			/* new left extent - oldext */
2485 			cur->bc_rec.b = PREV;
2486 			if ((error = xfs_btree_insert(cur, &i)))
2487 				goto done;
2488 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2489 				xfs_btree_mark_sick(cur);
2490 				error = -EFSCORRUPTED;
2491 				goto done;
2492 			}
2493 			/*
2494 			 * Reset the cursor to the position of the new extent
2495 			 * we are about to insert as we can't trust it after
2496 			 * the previous insert.
2497 			 */
2498 			error = xfs_bmbt_lookup_eq(cur, new, &i);
2499 			if (error)
2500 				goto done;
2501 			if (XFS_IS_CORRUPT(mp, i != 0)) {
2502 				xfs_btree_mark_sick(cur);
2503 				error = -EFSCORRUPTED;
2504 				goto done;
2505 			}
2506 			/* new middle extent - newext */
2507 			if ((error = xfs_btree_insert(cur, &i)))
2508 				goto done;
2509 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2510 				xfs_btree_mark_sick(cur);
2511 				error = -EFSCORRUPTED;
2512 				goto done;
2513 			}
2514 		}
2515 		break;
2516 
2517 	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2518 	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2519 	case BMAP_LEFT_FILLING | BMAP_RIGHT_CONTIG:
2520 	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
2521 	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2522 	case BMAP_LEFT_CONTIG:
2523 	case BMAP_RIGHT_CONTIG:
2524 		/*
2525 		 * These cases are all impossible.
2526 		 */
2527 		ASSERT(0);
2528 	}
2529 
2530 	/* update reverse mappings */
2531 	xfs_rmap_convert_extent(mp, tp, ip, whichfork, new);
2532 
2533 	/* convert to a btree if necessary */
2534 	if (xfs_bmap_needs_btree(ip, whichfork)) {
2535 		int	tmp_logflags;	/* partial log flag return val */
2536 
2537 		ASSERT(cur == NULL);
2538 		error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
2539 				&tmp_logflags, whichfork);
2540 		*logflagsp |= tmp_logflags;
2541 		if (error)
2542 			goto done;
2543 	}
2544 
2545 	/* clear out the allocated field, done with it now in any case. */
2546 	if (cur) {
2547 		cur->bc_bmap.allocated = 0;
2548 		*curp = cur;
2549 	}
2550 
2551 	xfs_bmap_check_leaf_extents(*curp, ip, whichfork);
2552 done:
2553 	*logflagsp |= rval;
2554 	return error;
2555 #undef	LEFT
2556 #undef	RIGHT
2557 #undef	PREV
2558 }
2559 
2560 /*
2561  * Convert a hole to a delayed allocation.
2562  */
2563 STATIC void
2564 xfs_bmap_add_extent_hole_delay(
2565 	xfs_inode_t		*ip,	/* incore inode pointer */
2566 	int			whichfork,
2567 	struct xfs_iext_cursor	*icur,
2568 	xfs_bmbt_irec_t		*new)	/* new data to add to file extents */
2569 {
2570 	struct xfs_ifork	*ifp;	/* inode fork pointer */
2571 	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
2572 	xfs_filblks_t		newlen=0;	/* new indirect size */
2573 	xfs_filblks_t		oldlen=0;	/* old indirect size */
2574 	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
2575 	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
2576 	xfs_filblks_t		temp;	 /* temp for indirect calculations */
2577 
2578 	ifp = xfs_ifork_ptr(ip, whichfork);
2579 	ASSERT(isnullstartblock(new->br_startblock));
2580 
2581 	/*
2582 	 * Check and set flags if this segment has a left neighbor
2583 	 */
2584 	if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
2585 		state |= BMAP_LEFT_VALID;
2586 		if (isnullstartblock(left.br_startblock))
2587 			state |= BMAP_LEFT_DELAY;
2588 	}
2589 
2590 	/*
2591 	 * Check and set flags if the current (right) segment exists.
2592 	 * If it doesn't exist, we're converting the hole at end-of-file.
2593 	 */
2594 	if (xfs_iext_get_extent(ifp, icur, &right)) {
2595 		state |= BMAP_RIGHT_VALID;
2596 		if (isnullstartblock(right.br_startblock))
2597 			state |= BMAP_RIGHT_DELAY;
2598 	}
2599 
2600 	/*
2601 	 * Set contiguity flags on the left and right neighbors.
2602 	 * Don't let extents get too large, even if the pieces are contiguous.
2603 	 */
2604 	if ((state & BMAP_LEFT_VALID) && (state & BMAP_LEFT_DELAY) &&
2605 	    left.br_startoff + left.br_blockcount == new->br_startoff &&
2606 	    left.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2607 		state |= BMAP_LEFT_CONTIG;
2608 
2609 	if ((state & BMAP_RIGHT_VALID) && (state & BMAP_RIGHT_DELAY) &&
2610 	    new->br_startoff + new->br_blockcount == right.br_startoff &&
2611 	    new->br_blockcount + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2612 	    (!(state & BMAP_LEFT_CONTIG) ||
2613 	     (left.br_blockcount + new->br_blockcount +
2614 	      right.br_blockcount <= XFS_MAX_BMBT_EXTLEN)))
2615 		state |= BMAP_RIGHT_CONTIG;
2616 
2617 	/*
2618 	 * Switch out based on the contiguity flags.
2619 	 */
2620 	switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
2621 	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2622 		/*
2623 		 * New allocation is contiguous with delayed allocations
2624 		 * on the left and on the right.
2625 		 * Merge all three into a single extent record.
2626 		 */
2627 		temp = left.br_blockcount + new->br_blockcount +
2628 			right.br_blockcount;
2629 
2630 		oldlen = startblockval(left.br_startblock) +
2631 			startblockval(new->br_startblock) +
2632 			startblockval(right.br_startblock);
2633 		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2634 					 oldlen);
2635 		left.br_startblock = nullstartblock(newlen);
2636 		left.br_blockcount = temp;
2637 
2638 		xfs_iext_remove(ip, icur, state);
2639 		xfs_iext_prev(ifp, icur);
2640 		xfs_iext_update_extent(ip, state, icur, &left);
2641 		break;
2642 
2643 	case BMAP_LEFT_CONTIG:
2644 		/*
2645 		 * New allocation is contiguous with a delayed allocation
2646 		 * on the left.
2647 		 * Merge the new allocation with the left neighbor.
2648 		 */
2649 		temp = left.br_blockcount + new->br_blockcount;
2650 
2651 		oldlen = startblockval(left.br_startblock) +
2652 			startblockval(new->br_startblock);
2653 		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2654 					 oldlen);
2655 		left.br_blockcount = temp;
2656 		left.br_startblock = nullstartblock(newlen);
2657 
2658 		xfs_iext_prev(ifp, icur);
2659 		xfs_iext_update_extent(ip, state, icur, &left);
2660 		break;
2661 
2662 	case BMAP_RIGHT_CONTIG:
2663 		/*
2664 		 * New allocation is contiguous with a delayed allocation
2665 		 * on the right.
2666 		 * Merge the new allocation with the right neighbor.
2667 		 */
2668 		temp = new->br_blockcount + right.br_blockcount;
2669 		oldlen = startblockval(new->br_startblock) +
2670 			startblockval(right.br_startblock);
2671 		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2672 					 oldlen);
2673 		right.br_startoff = new->br_startoff;
2674 		right.br_startblock = nullstartblock(newlen);
2675 		right.br_blockcount = temp;
2676 		xfs_iext_update_extent(ip, state, icur, &right);
2677 		break;
2678 
2679 	case 0:
2680 		/*
2681 		 * New allocation is not contiguous with another
2682 		 * delayed allocation.
2683 		 * Insert a new entry.
2684 		 */
2685 		oldlen = newlen = 0;
2686 		xfs_iext_insert(ip, icur, new, state);
2687 		break;
2688 	}
2689 	if (oldlen != newlen) {
2690 		ASSERT(oldlen > newlen);
2691 		xfs_mod_fdblocks(ip->i_mount, (int64_t)(oldlen - newlen),
2692 				 false);
2693 		/*
2694 		 * Nothing to do for disk quota accounting here.
2695 		 */
2696 		xfs_mod_delalloc(ip->i_mount, (int64_t)newlen - oldlen);
2697 	}
2698 }
2699 
2700 /*
2701  * Convert a hole to a real allocation.
2702  */
2703 STATIC int				/* error */
2704 xfs_bmap_add_extent_hole_real(
2705 	struct xfs_trans	*tp,
2706 	struct xfs_inode	*ip,
2707 	int			whichfork,
2708 	struct xfs_iext_cursor	*icur,
2709 	struct xfs_btree_cur	**curp,
2710 	struct xfs_bmbt_irec	*new,
2711 	int			*logflagsp,
2712 	uint32_t		flags)
2713 {
2714 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
2715 	struct xfs_mount	*mp = ip->i_mount;
2716 	struct xfs_btree_cur	*cur = *curp;
2717 	int			error;	/* error return value */
2718 	int			i;	/* temp state */
2719 	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
2720 	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
2721 	int			rval=0;	/* return value (logging flags) */
2722 	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
2723 	struct xfs_bmbt_irec	old;
2724 
2725 	ASSERT(!isnullstartblock(new->br_startblock));
2726 	ASSERT(!cur || !(cur->bc_flags & XFS_BTREE_BMBT_WASDEL));
2727 
2728 	XFS_STATS_INC(mp, xs_add_exlist);
2729 
2730 	/*
2731 	 * Check and set flags if this segment has a left neighbor.
2732 	 */
2733 	if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
2734 		state |= BMAP_LEFT_VALID;
2735 		if (isnullstartblock(left.br_startblock))
2736 			state |= BMAP_LEFT_DELAY;
2737 	}
2738 
2739 	/*
2740 	 * Check and set flags if this segment has a current value.
2741 	 * Not true if we're inserting into the "hole" at eof.
2742 	 */
2743 	if (xfs_iext_get_extent(ifp, icur, &right)) {
2744 		state |= BMAP_RIGHT_VALID;
2745 		if (isnullstartblock(right.br_startblock))
2746 			state |= BMAP_RIGHT_DELAY;
2747 	}
2748 
2749 	/*
2750 	 * We're inserting a real allocation between "left" and "right".
2751 	 * Set the contiguity flags.  Don't let extents get too large.
2752 	 */
2753 	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
2754 	    left.br_startoff + left.br_blockcount == new->br_startoff &&
2755 	    left.br_startblock + left.br_blockcount == new->br_startblock &&
2756 	    left.br_state == new->br_state &&
2757 	    left.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2758 		state |= BMAP_LEFT_CONTIG;
2759 
2760 	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
2761 	    new->br_startoff + new->br_blockcount == right.br_startoff &&
2762 	    new->br_startblock + new->br_blockcount == right.br_startblock &&
2763 	    new->br_state == right.br_state &&
2764 	    new->br_blockcount + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2765 	    (!(state & BMAP_LEFT_CONTIG) ||
2766 	     left.br_blockcount + new->br_blockcount +
2767 	     right.br_blockcount <= XFS_MAX_BMBT_EXTLEN))
2768 		state |= BMAP_RIGHT_CONTIG;
2769 
2770 	error = 0;
2771 	/*
2772 	 * Select which case we're in here, and implement it.
2773 	 */
2774 	switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
2775 	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2776 		/*
2777 		 * New allocation is contiguous with real allocations on the
2778 		 * left and on the right.
2779 		 * Merge all three into a single extent record.
2780 		 */
2781 		left.br_blockcount += new->br_blockcount + right.br_blockcount;
2782 
2783 		xfs_iext_remove(ip, icur, state);
2784 		xfs_iext_prev(ifp, icur);
2785 		xfs_iext_update_extent(ip, state, icur, &left);
2786 		ifp->if_nextents--;
2787 
2788 		if (cur == NULL) {
2789 			rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
2790 		} else {
2791 			rval = XFS_ILOG_CORE;
2792 			error = xfs_bmbt_lookup_eq(cur, &right, &i);
2793 			if (error)
2794 				goto done;
2795 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2796 				xfs_btree_mark_sick(cur);
2797 				error = -EFSCORRUPTED;
2798 				goto done;
2799 			}
2800 			error = xfs_btree_delete(cur, &i);
2801 			if (error)
2802 				goto done;
2803 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2804 				xfs_btree_mark_sick(cur);
2805 				error = -EFSCORRUPTED;
2806 				goto done;
2807 			}
2808 			error = xfs_btree_decrement(cur, 0, &i);
2809 			if (error)
2810 				goto done;
2811 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2812 				xfs_btree_mark_sick(cur);
2813 				error = -EFSCORRUPTED;
2814 				goto done;
2815 			}
2816 			error = xfs_bmbt_update(cur, &left);
2817 			if (error)
2818 				goto done;
2819 		}
2820 		break;
2821 
2822 	case BMAP_LEFT_CONTIG:
2823 		/*
2824 		 * New allocation is contiguous with a real allocation
2825 		 * on the left.
2826 		 * Merge the new allocation with the left neighbor.
2827 		 */
2828 		old = left;
2829 		left.br_blockcount += new->br_blockcount;
2830 
2831 		xfs_iext_prev(ifp, icur);
2832 		xfs_iext_update_extent(ip, state, icur, &left);
2833 
2834 		if (cur == NULL) {
2835 			rval = xfs_ilog_fext(whichfork);
2836 		} else {
2837 			rval = 0;
2838 			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2839 			if (error)
2840 				goto done;
2841 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2842 				xfs_btree_mark_sick(cur);
2843 				error = -EFSCORRUPTED;
2844 				goto done;
2845 			}
2846 			error = xfs_bmbt_update(cur, &left);
2847 			if (error)
2848 				goto done;
2849 		}
2850 		break;
2851 
2852 	case BMAP_RIGHT_CONTIG:
2853 		/*
2854 		 * New allocation is contiguous with a real allocation
2855 		 * on the right.
2856 		 * Merge the new allocation with the right neighbor.
2857 		 */
2858 		old = right;
2859 
2860 		right.br_startoff = new->br_startoff;
2861 		right.br_startblock = new->br_startblock;
2862 		right.br_blockcount += new->br_blockcount;
2863 		xfs_iext_update_extent(ip, state, icur, &right);
2864 
2865 		if (cur == NULL) {
2866 			rval = xfs_ilog_fext(whichfork);
2867 		} else {
2868 			rval = 0;
2869 			error = xfs_bmbt_lookup_eq(cur, &old, &i);
2870 			if (error)
2871 				goto done;
2872 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2873 				xfs_btree_mark_sick(cur);
2874 				error = -EFSCORRUPTED;
2875 				goto done;
2876 			}
2877 			error = xfs_bmbt_update(cur, &right);
2878 			if (error)
2879 				goto done;
2880 		}
2881 		break;
2882 
2883 	case 0:
2884 		/*
2885 		 * New allocation is not contiguous with another
2886 		 * real allocation.
2887 		 * Insert a new entry.
2888 		 */
2889 		xfs_iext_insert(ip, icur, new, state);
2890 		ifp->if_nextents++;
2891 
2892 		if (cur == NULL) {
2893 			rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
2894 		} else {
2895 			rval = XFS_ILOG_CORE;
2896 			error = xfs_bmbt_lookup_eq(cur, new, &i);
2897 			if (error)
2898 				goto done;
2899 			if (XFS_IS_CORRUPT(mp, i != 0)) {
2900 				xfs_btree_mark_sick(cur);
2901 				error = -EFSCORRUPTED;
2902 				goto done;
2903 			}
2904 			error = xfs_btree_insert(cur, &i);
2905 			if (error)
2906 				goto done;
2907 			if (XFS_IS_CORRUPT(mp, i != 1)) {
2908 				xfs_btree_mark_sick(cur);
2909 				error = -EFSCORRUPTED;
2910 				goto done;
2911 			}
2912 		}
2913 		break;
2914 	}
2915 
2916 	/* add reverse mapping unless caller opted out */
2917 	if (!(flags & XFS_BMAPI_NORMAP))
2918 		xfs_rmap_map_extent(tp, ip, whichfork, new);
2919 
2920 	/* convert to a btree if necessary */
2921 	if (xfs_bmap_needs_btree(ip, whichfork)) {
2922 		int	tmp_logflags;	/* partial log flag return val */
2923 
2924 		ASSERT(cur == NULL);
2925 		error = xfs_bmap_extents_to_btree(tp, ip, curp, 0,
2926 				&tmp_logflags, whichfork);
2927 		*logflagsp |= tmp_logflags;
2928 		cur = *curp;
2929 		if (error)
2930 			goto done;
2931 	}
2932 
2933 	/* clear out the allocated field, done with it now in any case. */
2934 	if (cur)
2935 		cur->bc_bmap.allocated = 0;
2936 
2937 	xfs_bmap_check_leaf_extents(cur, ip, whichfork);
2938 done:
2939 	*logflagsp |= rval;
2940 	return error;
2941 }
2942 
2943 /*
2944  * Functions used in the extent read, allocate and remove paths
2945  */
2946 
2947 /*
2948  * Adjust the size of the new extent based on i_extsize and rt extsize.
2949  */
2950 int
2951 xfs_bmap_extsize_align(
2952 	xfs_mount_t	*mp,
2953 	xfs_bmbt_irec_t	*gotp,		/* next extent pointer */
2954 	xfs_bmbt_irec_t	*prevp,		/* previous extent pointer */
2955 	xfs_extlen_t	extsz,		/* align to this extent size */
2956 	int		rt,		/* is this a realtime inode? */
2957 	int		eof,		/* is extent at end-of-file? */
2958 	int		delay,		/* creating delalloc extent? */
2959 	int		convert,	/* overwriting unwritten extent? */
2960 	xfs_fileoff_t	*offp,		/* in/out: aligned offset */
2961 	xfs_extlen_t	*lenp)		/* in/out: aligned length */
2962 {
2963 	xfs_fileoff_t	orig_off;	/* original offset */
2964 	xfs_extlen_t	orig_alen;	/* original length */
2965 	xfs_fileoff_t	orig_end;	/* original off+len */
2966 	xfs_fileoff_t	nexto;		/* next file offset */
2967 	xfs_fileoff_t	prevo;		/* previous file offset */
2968 	xfs_fileoff_t	align_off;	/* temp for offset */
2969 	xfs_extlen_t	align_alen;	/* temp for length */
2970 	xfs_extlen_t	temp;		/* temp for calculations */
2971 
2972 	if (convert)
2973 		return 0;
2974 
2975 	orig_off = align_off = *offp;
2976 	orig_alen = align_alen = *lenp;
2977 	orig_end = orig_off + orig_alen;
2978 
2979 	/*
2980 	 * If this request overlaps an existing extent, then don't
2981 	 * attempt to perform any additional alignment.
2982 	 */
2983 	if (!delay && !eof &&
2984 	    (orig_off >= gotp->br_startoff) &&
2985 	    (orig_end <= gotp->br_startoff + gotp->br_blockcount)) {
2986 		return 0;
2987 	}
2988 
2989 	/*
2990 	 * If the file offset is unaligned vs. the extent size
2991 	 * we need to align it.  This will be possible unless
2992 	 * the file was previously written with a kernel that didn't
2993 	 * perform this alignment, or if a truncate shot us in the
2994 	 * foot.
2995 	 */
2996 	div_u64_rem(orig_off, extsz, &temp);
2997 	if (temp) {
2998 		align_alen += temp;
2999 		align_off -= temp;
3000 	}
3001 
3002 	/* Same adjustment for the end of the requested area. */
3003 	temp = (align_alen % extsz);
3004 	if (temp)
3005 		align_alen += extsz - temp;
3006 
3007 	/*
3008 	 * For large extent hint sizes, the aligned extent might be larger than
3009 	 * XFS_BMBT_MAX_EXTLEN. In that case, reduce the size by an extsz so
3010 	 * that it pulls the length back under XFS_BMBT_MAX_EXTLEN. The outer
3011 	 * allocation loops handle short allocation just fine, so it is safe to
3012 	 * do this. We only want to do it when we are forced to, though, because
3013 	 * it means more allocation operations are required.
3014 	 */
3015 	while (align_alen > XFS_MAX_BMBT_EXTLEN)
3016 		align_alen -= extsz;
3017 	ASSERT(align_alen <= XFS_MAX_BMBT_EXTLEN);
3018 
3019 	/*
3020 	 * If the previous block overlaps with this proposed allocation
3021 	 * then move the start forward without adjusting the length.
3022 	 */
3023 	if (prevp->br_startoff != NULLFILEOFF) {
3024 		if (prevp->br_startblock == HOLESTARTBLOCK)
3025 			prevo = prevp->br_startoff;
3026 		else
3027 			prevo = prevp->br_startoff + prevp->br_blockcount;
3028 	} else
3029 		prevo = 0;
3030 	if (align_off != orig_off && align_off < prevo)
3031 		align_off = prevo;
3032 	/*
3033 	 * If the next block overlaps with this proposed allocation
3034 	 * then move the start back without adjusting the length,
3035 	 * but not before offset 0.
3036 	 * This may of course make the start overlap previous block,
3037 	 * and if we hit the offset 0 limit then the next block
3038 	 * can still overlap too.
3039 	 */
3040 	if (!eof && gotp->br_startoff != NULLFILEOFF) {
3041 		if ((delay && gotp->br_startblock == HOLESTARTBLOCK) ||
3042 		    (!delay && gotp->br_startblock == DELAYSTARTBLOCK))
3043 			nexto = gotp->br_startoff + gotp->br_blockcount;
3044 		else
3045 			nexto = gotp->br_startoff;
3046 	} else
3047 		nexto = NULLFILEOFF;
3048 	if (!eof &&
3049 	    align_off + align_alen != orig_end &&
3050 	    align_off + align_alen > nexto)
3051 		align_off = nexto > align_alen ? nexto - align_alen : 0;
3052 	/*
3053 	 * If we're now overlapping the next or previous extent that
3054 	 * means we can't fit an extsz piece in this hole.  Just move
3055 	 * the start forward to the first valid spot and set
3056 	 * the length so we hit the end.
3057 	 */
3058 	if (align_off != orig_off && align_off < prevo)
3059 		align_off = prevo;
3060 	if (align_off + align_alen != orig_end &&
3061 	    align_off + align_alen > nexto &&
3062 	    nexto != NULLFILEOFF) {
3063 		ASSERT(nexto > prevo);
3064 		align_alen = nexto - align_off;
3065 	}
3066 
3067 	/*
3068 	 * If realtime, and the result isn't a multiple of the realtime
3069 	 * extent size we need to remove blocks until it is.
3070 	 */
3071 	if (rt && (temp = xfs_extlen_to_rtxmod(mp, align_alen))) {
3072 		/*
3073 		 * We're not covering the original request, or
3074 		 * we won't be able to once we fix the length.
3075 		 */
3076 		if (orig_off < align_off ||
3077 		    orig_end > align_off + align_alen ||
3078 		    align_alen - temp < orig_alen)
3079 			return -EINVAL;
3080 		/*
3081 		 * Try to fix it by moving the start up.
3082 		 */
3083 		if (align_off + temp <= orig_off) {
3084 			align_alen -= temp;
3085 			align_off += temp;
3086 		}
3087 		/*
3088 		 * Try to fix it by moving the end in.
3089 		 */
3090 		else if (align_off + align_alen - temp >= orig_end)
3091 			align_alen -= temp;
3092 		/*
3093 		 * Set the start to the minimum then trim the length.
3094 		 */
3095 		else {
3096 			align_alen -= orig_off - align_off;
3097 			align_off = orig_off;
3098 			align_alen -= xfs_extlen_to_rtxmod(mp, align_alen);
3099 		}
3100 		/*
3101 		 * Result doesn't cover the request, fail it.
3102 		 */
3103 		if (orig_off < align_off || orig_end > align_off + align_alen)
3104 			return -EINVAL;
3105 	} else {
3106 		ASSERT(orig_off >= align_off);
3107 		/* see XFS_BMBT_MAX_EXTLEN handling above */
3108 		ASSERT(orig_end <= align_off + align_alen ||
3109 		       align_alen + extsz > XFS_MAX_BMBT_EXTLEN);
3110 	}
3111 
3112 #ifdef DEBUG
3113 	if (!eof && gotp->br_startoff != NULLFILEOFF)
3114 		ASSERT(align_off + align_alen <= gotp->br_startoff);
3115 	if (prevp->br_startoff != NULLFILEOFF)
3116 		ASSERT(align_off >= prevp->br_startoff + prevp->br_blockcount);
3117 #endif
3118 
3119 	*lenp = align_alen;
3120 	*offp = align_off;
3121 	return 0;
3122 }
3123 
3124 #define XFS_ALLOC_GAP_UNITS	4
3125 
3126 /* returns true if ap->blkno was modified */
3127 bool
3128 xfs_bmap_adjacent(
3129 	struct xfs_bmalloca	*ap)	/* bmap alloc argument struct */
3130 {
3131 	xfs_fsblock_t	adjust;		/* adjustment to block numbers */
3132 	xfs_mount_t	*mp;		/* mount point structure */
3133 	int		rt;		/* true if inode is realtime */
3134 
3135 #define	ISVALID(x,y)	\
3136 	(rt ? \
3137 		(x) < mp->m_sb.sb_rblocks : \
3138 		XFS_FSB_TO_AGNO(mp, x) == XFS_FSB_TO_AGNO(mp, y) && \
3139 		XFS_FSB_TO_AGNO(mp, x) < mp->m_sb.sb_agcount && \
3140 		XFS_FSB_TO_AGBNO(mp, x) < mp->m_sb.sb_agblocks)
3141 
3142 	mp = ap->ip->i_mount;
3143 	rt = XFS_IS_REALTIME_INODE(ap->ip) &&
3144 		(ap->datatype & XFS_ALLOC_USERDATA);
3145 	/*
3146 	 * If allocating at eof, and there's a previous real block,
3147 	 * try to use its last block as our starting point.
3148 	 */
3149 	if (ap->eof && ap->prev.br_startoff != NULLFILEOFF &&
3150 	    !isnullstartblock(ap->prev.br_startblock) &&
3151 	    ISVALID(ap->prev.br_startblock + ap->prev.br_blockcount,
3152 		    ap->prev.br_startblock)) {
3153 		ap->blkno = ap->prev.br_startblock + ap->prev.br_blockcount;
3154 		/*
3155 		 * Adjust for the gap between prevp and us.
3156 		 */
3157 		adjust = ap->offset -
3158 			(ap->prev.br_startoff + ap->prev.br_blockcount);
3159 		if (adjust &&
3160 		    ISVALID(ap->blkno + adjust, ap->prev.br_startblock))
3161 			ap->blkno += adjust;
3162 		return true;
3163 	}
3164 	/*
3165 	 * If not at eof, then compare the two neighbor blocks.
3166 	 * Figure out whether either one gives us a good starting point,
3167 	 * and pick the better one.
3168 	 */
3169 	if (!ap->eof) {
3170 		xfs_fsblock_t	gotbno;		/* right side block number */
3171 		xfs_fsblock_t	gotdiff=0;	/* right side difference */
3172 		xfs_fsblock_t	prevbno;	/* left side block number */
3173 		xfs_fsblock_t	prevdiff=0;	/* left side difference */
3174 
3175 		/*
3176 		 * If there's a previous (left) block, select a requested
3177 		 * start block based on it.
3178 		 */
3179 		if (ap->prev.br_startoff != NULLFILEOFF &&
3180 		    !isnullstartblock(ap->prev.br_startblock) &&
3181 		    (prevbno = ap->prev.br_startblock +
3182 			       ap->prev.br_blockcount) &&
3183 		    ISVALID(prevbno, ap->prev.br_startblock)) {
3184 			/*
3185 			 * Calculate gap to end of previous block.
3186 			 */
3187 			adjust = prevdiff = ap->offset -
3188 				(ap->prev.br_startoff +
3189 				 ap->prev.br_blockcount);
3190 			/*
3191 			 * Figure the startblock based on the previous block's
3192 			 * end and the gap size.
3193 			 * Heuristic!
3194 			 * If the gap is large relative to the piece we're
3195 			 * allocating, or using it gives us an invalid block
3196 			 * number, then just use the end of the previous block.
3197 			 */
3198 			if (prevdiff <= XFS_ALLOC_GAP_UNITS * ap->length &&
3199 			    ISVALID(prevbno + prevdiff,
3200 				    ap->prev.br_startblock))
3201 				prevbno += adjust;
3202 			else
3203 				prevdiff += adjust;
3204 		}
3205 		/*
3206 		 * No previous block or can't follow it, just default.
3207 		 */
3208 		else
3209 			prevbno = NULLFSBLOCK;
3210 		/*
3211 		 * If there's a following (right) block, select a requested
3212 		 * start block based on it.
3213 		 */
3214 		if (!isnullstartblock(ap->got.br_startblock)) {
3215 			/*
3216 			 * Calculate gap to start of next block.
3217 			 */
3218 			adjust = gotdiff = ap->got.br_startoff - ap->offset;
3219 			/*
3220 			 * Figure the startblock based on the next block's
3221 			 * start and the gap size.
3222 			 */
3223 			gotbno = ap->got.br_startblock;
3224 			/*
3225 			 * Heuristic!
3226 			 * If the gap is large relative to the piece we're
3227 			 * allocating, or using it gives us an invalid block
3228 			 * number, then just use the start of the next block
3229 			 * offset by our length.
3230 			 */
3231 			if (gotdiff <= XFS_ALLOC_GAP_UNITS * ap->length &&
3232 			    ISVALID(gotbno - gotdiff, gotbno))
3233 				gotbno -= adjust;
3234 			else if (ISVALID(gotbno - ap->length, gotbno)) {
3235 				gotbno -= ap->length;
3236 				gotdiff += adjust - ap->length;
3237 			} else
3238 				gotdiff += adjust;
3239 		}
3240 		/*
3241 		 * No next block, just default.
3242 		 */
3243 		else
3244 			gotbno = NULLFSBLOCK;
3245 		/*
3246 		 * If both valid, pick the better one, else the only good
3247 		 * one, else ap->blkno is already set (to 0 or the inode block).
3248 		 */
3249 		if (prevbno != NULLFSBLOCK && gotbno != NULLFSBLOCK) {
3250 			ap->blkno = prevdiff <= gotdiff ? prevbno : gotbno;
3251 			return true;
3252 		}
3253 		if (prevbno != NULLFSBLOCK) {
3254 			ap->blkno = prevbno;
3255 			return true;
3256 		}
3257 		if (gotbno != NULLFSBLOCK) {
3258 			ap->blkno = gotbno;
3259 			return true;
3260 		}
3261 	}
3262 #undef ISVALID
3263 	return false;
3264 }
3265 
3266 int
3267 xfs_bmap_longest_free_extent(
3268 	struct xfs_perag	*pag,
3269 	struct xfs_trans	*tp,
3270 	xfs_extlen_t		*blen)
3271 {
3272 	xfs_extlen_t		longest;
3273 	int			error = 0;
3274 
3275 	if (!xfs_perag_initialised_agf(pag)) {
3276 		error = xfs_alloc_read_agf(pag, tp, XFS_ALLOC_FLAG_TRYLOCK,
3277 				NULL);
3278 		if (error)
3279 			return error;
3280 	}
3281 
3282 	longest = xfs_alloc_longest_free_extent(pag,
3283 				xfs_alloc_min_freelist(pag->pag_mount, pag),
3284 				xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE));
3285 	if (*blen < longest)
3286 		*blen = longest;
3287 
3288 	return 0;
3289 }
3290 
3291 static xfs_extlen_t
3292 xfs_bmap_select_minlen(
3293 	struct xfs_bmalloca	*ap,
3294 	struct xfs_alloc_arg	*args,
3295 	xfs_extlen_t		blen)
3296 {
3297 
3298 	/*
3299 	 * Since we used XFS_ALLOC_FLAG_TRYLOCK in _longest_free_extent(), it is
3300 	 * possible that there is enough contiguous free space for this request.
3301 	 */
3302 	if (blen < ap->minlen)
3303 		return ap->minlen;
3304 
3305 	/*
3306 	 * If the best seen length is less than the request length,
3307 	 * use the best as the minimum, otherwise we've got the maxlen we
3308 	 * were asked for.
3309 	 */
3310 	if (blen < args->maxlen)
3311 		return blen;
3312 	return args->maxlen;
3313 }
3314 
3315 static int
3316 xfs_bmap_btalloc_select_lengths(
3317 	struct xfs_bmalloca	*ap,
3318 	struct xfs_alloc_arg	*args,
3319 	xfs_extlen_t		*blen)
3320 {
3321 	struct xfs_mount	*mp = args->mp;
3322 	struct xfs_perag	*pag;
3323 	xfs_agnumber_t		agno, startag;
3324 	int			error = 0;
3325 
3326 	if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
3327 		args->total = ap->minlen;
3328 		args->minlen = ap->minlen;
3329 		return 0;
3330 	}
3331 
3332 	args->total = ap->total;
3333 	startag = XFS_FSB_TO_AGNO(mp, ap->blkno);
3334 	if (startag == NULLAGNUMBER)
3335 		startag = 0;
3336 
3337 	*blen = 0;
3338 	for_each_perag_wrap(mp, startag, agno, pag) {
3339 		error = xfs_bmap_longest_free_extent(pag, args->tp, blen);
3340 		if (error && error != -EAGAIN)
3341 			break;
3342 		error = 0;
3343 		if (*blen >= args->maxlen)
3344 			break;
3345 	}
3346 	if (pag)
3347 		xfs_perag_rele(pag);
3348 
3349 	args->minlen = xfs_bmap_select_minlen(ap, args, *blen);
3350 	return error;
3351 }
3352 
3353 /* Update all inode and quota accounting for the allocation we just did. */
3354 void
3355 xfs_bmap_alloc_account(
3356 	struct xfs_bmalloca	*ap)
3357 {
3358 	bool			isrt = XFS_IS_REALTIME_INODE(ap->ip) &&
3359 					!(ap->flags & XFS_BMAPI_ATTRFORK);
3360 	uint			fld;
3361 
3362 	if (ap->flags & XFS_BMAPI_COWFORK) {
3363 		/*
3364 		 * COW fork blocks are in-core only and thus are treated as
3365 		 * in-core quota reservation (like delalloc blocks) even when
3366 		 * converted to real blocks. The quota reservation is not
3367 		 * accounted to disk until blocks are remapped to the data
3368 		 * fork. So if these blocks were previously delalloc, we
3369 		 * already have quota reservation and there's nothing to do
3370 		 * yet.
3371 		 */
3372 		if (ap->wasdel) {
3373 			xfs_mod_delalloc(ap->ip->i_mount, -(int64_t)ap->length);
3374 			return;
3375 		}
3376 
3377 		/*
3378 		 * Otherwise, we've allocated blocks in a hole. The transaction
3379 		 * has acquired in-core quota reservation for this extent.
3380 		 * Rather than account these as real blocks, however, we reduce
3381 		 * the transaction quota reservation based on the allocation.
3382 		 * This essentially transfers the transaction quota reservation
3383 		 * to that of a delalloc extent.
3384 		 */
3385 		ap->ip->i_delayed_blks += ap->length;
3386 		xfs_trans_mod_dquot_byino(ap->tp, ap->ip, isrt ?
3387 				XFS_TRANS_DQ_RES_RTBLKS : XFS_TRANS_DQ_RES_BLKS,
3388 				-(long)ap->length);
3389 		return;
3390 	}
3391 
3392 	/* data/attr fork only */
3393 	ap->ip->i_nblocks += ap->length;
3394 	xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
3395 	if (ap->wasdel) {
3396 		ap->ip->i_delayed_blks -= ap->length;
3397 		xfs_mod_delalloc(ap->ip->i_mount, -(int64_t)ap->length);
3398 		fld = isrt ? XFS_TRANS_DQ_DELRTBCOUNT : XFS_TRANS_DQ_DELBCOUNT;
3399 	} else {
3400 		fld = isrt ? XFS_TRANS_DQ_RTBCOUNT : XFS_TRANS_DQ_BCOUNT;
3401 	}
3402 
3403 	xfs_trans_mod_dquot_byino(ap->tp, ap->ip, fld, ap->length);
3404 }
3405 
3406 static int
3407 xfs_bmap_compute_alignments(
3408 	struct xfs_bmalloca	*ap,
3409 	struct xfs_alloc_arg	*args)
3410 {
3411 	struct xfs_mount	*mp = args->mp;
3412 	xfs_extlen_t		align = 0; /* minimum allocation alignment */
3413 	int			stripe_align = 0;
3414 
3415 	/* stripe alignment for allocation is determined by mount parameters */
3416 	if (mp->m_swidth && xfs_has_swalloc(mp))
3417 		stripe_align = mp->m_swidth;
3418 	else if (mp->m_dalign)
3419 		stripe_align = mp->m_dalign;
3420 
3421 	if (ap->flags & XFS_BMAPI_COWFORK)
3422 		align = xfs_get_cowextsz_hint(ap->ip);
3423 	else if (ap->datatype & XFS_ALLOC_USERDATA)
3424 		align = xfs_get_extsz_hint(ap->ip);
3425 	if (align) {
3426 		if (xfs_bmap_extsize_align(mp, &ap->got, &ap->prev, align, 0,
3427 					ap->eof, 0, ap->conv, &ap->offset,
3428 					&ap->length))
3429 			ASSERT(0);
3430 		ASSERT(ap->length);
3431 	}
3432 
3433 	/* apply extent size hints if obtained earlier */
3434 	if (align) {
3435 		args->prod = align;
3436 		div_u64_rem(ap->offset, args->prod, &args->mod);
3437 		if (args->mod)
3438 			args->mod = args->prod - args->mod;
3439 	} else if (mp->m_sb.sb_blocksize >= PAGE_SIZE) {
3440 		args->prod = 1;
3441 		args->mod = 0;
3442 	} else {
3443 		args->prod = PAGE_SIZE >> mp->m_sb.sb_blocklog;
3444 		div_u64_rem(ap->offset, args->prod, &args->mod);
3445 		if (args->mod)
3446 			args->mod = args->prod - args->mod;
3447 	}
3448 
3449 	return stripe_align;
3450 }
3451 
3452 static void
3453 xfs_bmap_process_allocated_extent(
3454 	struct xfs_bmalloca	*ap,
3455 	struct xfs_alloc_arg	*args,
3456 	xfs_fileoff_t		orig_offset,
3457 	xfs_extlen_t		orig_length)
3458 {
3459 	ap->blkno = args->fsbno;
3460 	ap->length = args->len;
3461 	/*
3462 	 * If the extent size hint is active, we tried to round the
3463 	 * caller's allocation request offset down to extsz and the
3464 	 * length up to another extsz boundary.  If we found a free
3465 	 * extent we mapped it in starting at this new offset.  If the
3466 	 * newly mapped space isn't long enough to cover any of the
3467 	 * range of offsets that was originally requested, move the
3468 	 * mapping up so that we can fill as much of the caller's
3469 	 * original request as possible.  Free space is apparently
3470 	 * very fragmented so we're unlikely to be able to satisfy the
3471 	 * hints anyway.
3472 	 */
3473 	if (ap->length <= orig_length)
3474 		ap->offset = orig_offset;
3475 	else if (ap->offset + ap->length < orig_offset + orig_length)
3476 		ap->offset = orig_offset + orig_length - ap->length;
3477 	xfs_bmap_alloc_account(ap);
3478 }
3479 
3480 #ifdef DEBUG
3481 static int
3482 xfs_bmap_exact_minlen_extent_alloc(
3483 	struct xfs_bmalloca	*ap)
3484 {
3485 	struct xfs_mount	*mp = ap->ip->i_mount;
3486 	struct xfs_alloc_arg	args = { .tp = ap->tp, .mp = mp };
3487 	xfs_fileoff_t		orig_offset;
3488 	xfs_extlen_t		orig_length;
3489 	int			error;
3490 
3491 	ASSERT(ap->length);
3492 
3493 	if (ap->minlen != 1) {
3494 		ap->blkno = NULLFSBLOCK;
3495 		ap->length = 0;
3496 		return 0;
3497 	}
3498 
3499 	orig_offset = ap->offset;
3500 	orig_length = ap->length;
3501 
3502 	args.alloc_minlen_only = 1;
3503 
3504 	xfs_bmap_compute_alignments(ap, &args);
3505 
3506 	/*
3507 	 * Unlike the longest extent available in an AG, we don't track
3508 	 * the length of an AG's shortest extent.
3509 	 * XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT is a debug only knob and
3510 	 * hence we can afford to start traversing from the 0th AG since
3511 	 * we need not be concerned about a drop in performance in
3512 	 * "debug only" code paths.
3513 	 */
3514 	ap->blkno = XFS_AGB_TO_FSB(mp, 0, 0);
3515 
3516 	args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
3517 	args.minlen = args.maxlen = ap->minlen;
3518 	args.total = ap->total;
3519 
3520 	args.alignment = 1;
3521 	args.minalignslop = 0;
3522 
3523 	args.minleft = ap->minleft;
3524 	args.wasdel = ap->wasdel;
3525 	args.resv = XFS_AG_RESV_NONE;
3526 	args.datatype = ap->datatype;
3527 
3528 	error = xfs_alloc_vextent_first_ag(&args, ap->blkno);
3529 	if (error)
3530 		return error;
3531 
3532 	if (args.fsbno != NULLFSBLOCK) {
3533 		xfs_bmap_process_allocated_extent(ap, &args, orig_offset,
3534 			orig_length);
3535 	} else {
3536 		ap->blkno = NULLFSBLOCK;
3537 		ap->length = 0;
3538 	}
3539 
3540 	return 0;
3541 }
3542 #else
3543 
3544 #define xfs_bmap_exact_minlen_extent_alloc(bma) (-EFSCORRUPTED)
3545 
3546 #endif
3547 
3548 /*
3549  * If we are not low on available data blocks and we are allocating at
3550  * EOF, optimise allocation for contiguous file extension and/or stripe
3551  * alignment of the new extent.
3552  *
3553  * NOTE: ap->aeof is only set if the allocation length is >= the
3554  * stripe unit and the allocation offset is at the end of file.
3555  */
3556 static int
3557 xfs_bmap_btalloc_at_eof(
3558 	struct xfs_bmalloca	*ap,
3559 	struct xfs_alloc_arg	*args,
3560 	xfs_extlen_t		blen,
3561 	int			stripe_align,
3562 	bool			ag_only)
3563 {
3564 	struct xfs_mount	*mp = args->mp;
3565 	struct xfs_perag	*caller_pag = args->pag;
3566 	int			error;
3567 
3568 	/*
3569 	 * If there are already extents in the file, try an exact EOF block
3570 	 * allocation to extend the file as a contiguous extent. If that fails,
3571 	 * or it's the first allocation in a file, just try for a stripe aligned
3572 	 * allocation.
3573 	 */
3574 	if (ap->offset) {
3575 		xfs_extlen_t	nextminlen = 0;
3576 
3577 		/*
3578 		 * Compute the minlen+alignment for the next case.  Set slop so
3579 		 * that the value of minlen+alignment+slop doesn't go up between
3580 		 * the calls.
3581 		 */
3582 		args->alignment = 1;
3583 		if (blen > stripe_align && blen <= args->maxlen)
3584 			nextminlen = blen - stripe_align;
3585 		else
3586 			nextminlen = args->minlen;
3587 		if (nextminlen + stripe_align > args->minlen + 1)
3588 			args->minalignslop = nextminlen + stripe_align -
3589 					args->minlen - 1;
3590 		else
3591 			args->minalignslop = 0;
3592 
3593 		if (!caller_pag)
3594 			args->pag = xfs_perag_get(mp, XFS_FSB_TO_AGNO(mp, ap->blkno));
3595 		error = xfs_alloc_vextent_exact_bno(args, ap->blkno);
3596 		if (!caller_pag) {
3597 			xfs_perag_put(args->pag);
3598 			args->pag = NULL;
3599 		}
3600 		if (error)
3601 			return error;
3602 
3603 		if (args->fsbno != NULLFSBLOCK)
3604 			return 0;
3605 		/*
3606 		 * Exact allocation failed. Reset to try an aligned allocation
3607 		 * according to the original allocation specification.
3608 		 */
3609 		args->alignment = stripe_align;
3610 		args->minlen = nextminlen;
3611 		args->minalignslop = 0;
3612 	} else {
3613 		/*
3614 		 * Adjust minlen to try and preserve alignment if we
3615 		 * can't guarantee an aligned maxlen extent.
3616 		 */
3617 		args->alignment = stripe_align;
3618 		if (blen > args->alignment &&
3619 		    blen <= args->maxlen + args->alignment)
3620 			args->minlen = blen - args->alignment;
3621 		args->minalignslop = 0;
3622 	}
3623 
3624 	if (ag_only) {
3625 		error = xfs_alloc_vextent_near_bno(args, ap->blkno);
3626 	} else {
3627 		args->pag = NULL;
3628 		error = xfs_alloc_vextent_start_ag(args, ap->blkno);
3629 		ASSERT(args->pag == NULL);
3630 		args->pag = caller_pag;
3631 	}
3632 	if (error)
3633 		return error;
3634 
3635 	if (args->fsbno != NULLFSBLOCK)
3636 		return 0;
3637 
3638 	/*
3639 	 * Allocation failed, so turn return the allocation args to their
3640 	 * original non-aligned state so the caller can proceed on allocation
3641 	 * failure as if this function was never called.
3642 	 */
3643 	args->alignment = 1;
3644 	return 0;
3645 }
3646 
3647 /*
3648  * We have failed multiple allocation attempts so now are in a low space
3649  * allocation situation. Try a locality first full filesystem minimum length
3650  * allocation whilst still maintaining necessary total block reservation
3651  * requirements.
3652  *
3653  * If that fails, we are now critically low on space, so perform a last resort
3654  * allocation attempt: no reserve, no locality, blocking, minimum length, full
3655  * filesystem free space scan. We also indicate to future allocations in this
3656  * transaction that we are critically low on space so they don't waste time on
3657  * allocation modes that are unlikely to succeed.
3658  */
3659 int
3660 xfs_bmap_btalloc_low_space(
3661 	struct xfs_bmalloca	*ap,
3662 	struct xfs_alloc_arg	*args)
3663 {
3664 	int			error;
3665 
3666 	if (args->minlen > ap->minlen) {
3667 		args->minlen = ap->minlen;
3668 		error = xfs_alloc_vextent_start_ag(args, ap->blkno);
3669 		if (error || args->fsbno != NULLFSBLOCK)
3670 			return error;
3671 	}
3672 
3673 	/* Last ditch attempt before failure is declared. */
3674 	args->total = ap->minlen;
3675 	error = xfs_alloc_vextent_first_ag(args, 0);
3676 	if (error)
3677 		return error;
3678 	ap->tp->t_flags |= XFS_TRANS_LOWMODE;
3679 	return 0;
3680 }
3681 
3682 static int
3683 xfs_bmap_btalloc_filestreams(
3684 	struct xfs_bmalloca	*ap,
3685 	struct xfs_alloc_arg	*args,
3686 	int			stripe_align)
3687 {
3688 	xfs_extlen_t		blen = 0;
3689 	int			error = 0;
3690 
3691 
3692 	error = xfs_filestream_select_ag(ap, args, &blen);
3693 	if (error)
3694 		return error;
3695 	ASSERT(args->pag);
3696 
3697 	/*
3698 	 * If we are in low space mode, then optimal allocation will fail so
3699 	 * prepare for minimal allocation and jump to the low space algorithm
3700 	 * immediately.
3701 	 */
3702 	if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
3703 		args->minlen = ap->minlen;
3704 		ASSERT(args->fsbno == NULLFSBLOCK);
3705 		goto out_low_space;
3706 	}
3707 
3708 	args->minlen = xfs_bmap_select_minlen(ap, args, blen);
3709 	if (ap->aeof)
3710 		error = xfs_bmap_btalloc_at_eof(ap, args, blen, stripe_align,
3711 				true);
3712 
3713 	if (!error && args->fsbno == NULLFSBLOCK)
3714 		error = xfs_alloc_vextent_near_bno(args, ap->blkno);
3715 
3716 out_low_space:
3717 	/*
3718 	 * We are now done with the perag reference for the filestreams
3719 	 * association provided by xfs_filestream_select_ag(). Release it now as
3720 	 * we've either succeeded, had a fatal error or we are out of space and
3721 	 * need to do a full filesystem scan for free space which will take it's
3722 	 * own references.
3723 	 */
3724 	xfs_perag_rele(args->pag);
3725 	args->pag = NULL;
3726 	if (error || args->fsbno != NULLFSBLOCK)
3727 		return error;
3728 
3729 	return xfs_bmap_btalloc_low_space(ap, args);
3730 }
3731 
3732 static int
3733 xfs_bmap_btalloc_best_length(
3734 	struct xfs_bmalloca	*ap,
3735 	struct xfs_alloc_arg	*args,
3736 	int			stripe_align)
3737 {
3738 	xfs_extlen_t		blen = 0;
3739 	int			error;
3740 
3741 	ap->blkno = XFS_INO_TO_FSB(args->mp, ap->ip->i_ino);
3742 	xfs_bmap_adjacent(ap);
3743 
3744 	/*
3745 	 * Search for an allocation group with a single extent large enough for
3746 	 * the request.  If one isn't found, then adjust the minimum allocation
3747 	 * size to the largest space found.
3748 	 */
3749 	error = xfs_bmap_btalloc_select_lengths(ap, args, &blen);
3750 	if (error)
3751 		return error;
3752 
3753 	/*
3754 	 * Don't attempt optimal EOF allocation if previous allocations barely
3755 	 * succeeded due to being near ENOSPC. It is highly unlikely we'll get
3756 	 * optimal or even aligned allocations in this case, so don't waste time
3757 	 * trying.
3758 	 */
3759 	if (ap->aeof && !(ap->tp->t_flags & XFS_TRANS_LOWMODE)) {
3760 		error = xfs_bmap_btalloc_at_eof(ap, args, blen, stripe_align,
3761 				false);
3762 		if (error || args->fsbno != NULLFSBLOCK)
3763 			return error;
3764 	}
3765 
3766 	error = xfs_alloc_vextent_start_ag(args, ap->blkno);
3767 	if (error || args->fsbno != NULLFSBLOCK)
3768 		return error;
3769 
3770 	return xfs_bmap_btalloc_low_space(ap, args);
3771 }
3772 
3773 static int
3774 xfs_bmap_btalloc(
3775 	struct xfs_bmalloca	*ap)
3776 {
3777 	struct xfs_mount	*mp = ap->ip->i_mount;
3778 	struct xfs_alloc_arg	args = {
3779 		.tp		= ap->tp,
3780 		.mp		= mp,
3781 		.fsbno		= NULLFSBLOCK,
3782 		.oinfo		= XFS_RMAP_OINFO_SKIP_UPDATE,
3783 		.minleft	= ap->minleft,
3784 		.wasdel		= ap->wasdel,
3785 		.resv		= XFS_AG_RESV_NONE,
3786 		.datatype	= ap->datatype,
3787 		.alignment	= 1,
3788 		.minalignslop	= 0,
3789 	};
3790 	xfs_fileoff_t		orig_offset;
3791 	xfs_extlen_t		orig_length;
3792 	int			error;
3793 	int			stripe_align;
3794 
3795 	ASSERT(ap->length);
3796 	orig_offset = ap->offset;
3797 	orig_length = ap->length;
3798 
3799 	stripe_align = xfs_bmap_compute_alignments(ap, &args);
3800 
3801 	/* Trim the allocation back to the maximum an AG can fit. */
3802 	args.maxlen = min(ap->length, mp->m_ag_max_usable);
3803 
3804 	if ((ap->datatype & XFS_ALLOC_USERDATA) &&
3805 	    xfs_inode_is_filestream(ap->ip))
3806 		error = xfs_bmap_btalloc_filestreams(ap, &args, stripe_align);
3807 	else
3808 		error = xfs_bmap_btalloc_best_length(ap, &args, stripe_align);
3809 	if (error)
3810 		return error;
3811 
3812 	if (args.fsbno != NULLFSBLOCK) {
3813 		xfs_bmap_process_allocated_extent(ap, &args, orig_offset,
3814 			orig_length);
3815 	} else {
3816 		ap->blkno = NULLFSBLOCK;
3817 		ap->length = 0;
3818 	}
3819 	return 0;
3820 }
3821 
3822 /* Trim extent to fit a logical block range. */
3823 void
3824 xfs_trim_extent(
3825 	struct xfs_bmbt_irec	*irec,
3826 	xfs_fileoff_t		bno,
3827 	xfs_filblks_t		len)
3828 {
3829 	xfs_fileoff_t		distance;
3830 	xfs_fileoff_t		end = bno + len;
3831 
3832 	if (irec->br_startoff + irec->br_blockcount <= bno ||
3833 	    irec->br_startoff >= end) {
3834 		irec->br_blockcount = 0;
3835 		return;
3836 	}
3837 
3838 	if (irec->br_startoff < bno) {
3839 		distance = bno - irec->br_startoff;
3840 		if (isnullstartblock(irec->br_startblock))
3841 			irec->br_startblock = DELAYSTARTBLOCK;
3842 		if (irec->br_startblock != DELAYSTARTBLOCK &&
3843 		    irec->br_startblock != HOLESTARTBLOCK)
3844 			irec->br_startblock += distance;
3845 		irec->br_startoff += distance;
3846 		irec->br_blockcount -= distance;
3847 	}
3848 
3849 	if (end < irec->br_startoff + irec->br_blockcount) {
3850 		distance = irec->br_startoff + irec->br_blockcount - end;
3851 		irec->br_blockcount -= distance;
3852 	}
3853 }
3854 
3855 /*
3856  * Trim the returned map to the required bounds
3857  */
3858 STATIC void
3859 xfs_bmapi_trim_map(
3860 	struct xfs_bmbt_irec	*mval,
3861 	struct xfs_bmbt_irec	*got,
3862 	xfs_fileoff_t		*bno,
3863 	xfs_filblks_t		len,
3864 	xfs_fileoff_t		obno,
3865 	xfs_fileoff_t		end,
3866 	int			n,
3867 	uint32_t		flags)
3868 {
3869 	if ((flags & XFS_BMAPI_ENTIRE) ||
3870 	    got->br_startoff + got->br_blockcount <= obno) {
3871 		*mval = *got;
3872 		if (isnullstartblock(got->br_startblock))
3873 			mval->br_startblock = DELAYSTARTBLOCK;
3874 		return;
3875 	}
3876 
3877 	if (obno > *bno)
3878 		*bno = obno;
3879 	ASSERT((*bno >= obno) || (n == 0));
3880 	ASSERT(*bno < end);
3881 	mval->br_startoff = *bno;
3882 	if (isnullstartblock(got->br_startblock))
3883 		mval->br_startblock = DELAYSTARTBLOCK;
3884 	else
3885 		mval->br_startblock = got->br_startblock +
3886 					(*bno - got->br_startoff);
3887 	/*
3888 	 * Return the minimum of what we got and what we asked for for
3889 	 * the length.  We can use the len variable here because it is
3890 	 * modified below and we could have been there before coming
3891 	 * here if the first part of the allocation didn't overlap what
3892 	 * was asked for.
3893 	 */
3894 	mval->br_blockcount = XFS_FILBLKS_MIN(end - *bno,
3895 			got->br_blockcount - (*bno - got->br_startoff));
3896 	mval->br_state = got->br_state;
3897 	ASSERT(mval->br_blockcount <= len);
3898 	return;
3899 }
3900 
3901 /*
3902  * Update and validate the extent map to return
3903  */
3904 STATIC void
3905 xfs_bmapi_update_map(
3906 	struct xfs_bmbt_irec	**map,
3907 	xfs_fileoff_t		*bno,
3908 	xfs_filblks_t		*len,
3909 	xfs_fileoff_t		obno,
3910 	xfs_fileoff_t		end,
3911 	int			*n,
3912 	uint32_t		flags)
3913 {
3914 	xfs_bmbt_irec_t	*mval = *map;
3915 
3916 	ASSERT((flags & XFS_BMAPI_ENTIRE) ||
3917 	       ((mval->br_startoff + mval->br_blockcount) <= end));
3918 	ASSERT((flags & XFS_BMAPI_ENTIRE) || (mval->br_blockcount <= *len) ||
3919 	       (mval->br_startoff < obno));
3920 
3921 	*bno = mval->br_startoff + mval->br_blockcount;
3922 	*len = end - *bno;
3923 	if (*n > 0 && mval->br_startoff == mval[-1].br_startoff) {
3924 		/* update previous map with new information */
3925 		ASSERT(mval->br_startblock == mval[-1].br_startblock);
3926 		ASSERT(mval->br_blockcount > mval[-1].br_blockcount);
3927 		ASSERT(mval->br_state == mval[-1].br_state);
3928 		mval[-1].br_blockcount = mval->br_blockcount;
3929 		mval[-1].br_state = mval->br_state;
3930 	} else if (*n > 0 && mval->br_startblock != DELAYSTARTBLOCK &&
3931 		   mval[-1].br_startblock != DELAYSTARTBLOCK &&
3932 		   mval[-1].br_startblock != HOLESTARTBLOCK &&
3933 		   mval->br_startblock == mval[-1].br_startblock +
3934 					  mval[-1].br_blockcount &&
3935 		   mval[-1].br_state == mval->br_state) {
3936 		ASSERT(mval->br_startoff ==
3937 		       mval[-1].br_startoff + mval[-1].br_blockcount);
3938 		mval[-1].br_blockcount += mval->br_blockcount;
3939 	} else if (*n > 0 &&
3940 		   mval->br_startblock == DELAYSTARTBLOCK &&
3941 		   mval[-1].br_startblock == DELAYSTARTBLOCK &&
3942 		   mval->br_startoff ==
3943 		   mval[-1].br_startoff + mval[-1].br_blockcount) {
3944 		mval[-1].br_blockcount += mval->br_blockcount;
3945 		mval[-1].br_state = mval->br_state;
3946 	} else if (!((*n == 0) &&
3947 		     ((mval->br_startoff + mval->br_blockcount) <=
3948 		      obno))) {
3949 		mval++;
3950 		(*n)++;
3951 	}
3952 	*map = mval;
3953 }
3954 
3955 /*
3956  * Map file blocks to filesystem blocks without allocation.
3957  */
3958 int
3959 xfs_bmapi_read(
3960 	struct xfs_inode	*ip,
3961 	xfs_fileoff_t		bno,
3962 	xfs_filblks_t		len,
3963 	struct xfs_bmbt_irec	*mval,
3964 	int			*nmap,
3965 	uint32_t		flags)
3966 {
3967 	struct xfs_mount	*mp = ip->i_mount;
3968 	int			whichfork = xfs_bmapi_whichfork(flags);
3969 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
3970 	struct xfs_bmbt_irec	got;
3971 	xfs_fileoff_t		obno;
3972 	xfs_fileoff_t		end;
3973 	struct xfs_iext_cursor	icur;
3974 	int			error;
3975 	bool			eof = false;
3976 	int			n = 0;
3977 
3978 	ASSERT(*nmap >= 1);
3979 	ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK | XFS_BMAPI_ENTIRE)));
3980 	xfs_assert_ilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL);
3981 
3982 	if (WARN_ON_ONCE(!ifp)) {
3983 		xfs_bmap_mark_sick(ip, whichfork);
3984 		return -EFSCORRUPTED;
3985 	}
3986 
3987 	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
3988 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
3989 		xfs_bmap_mark_sick(ip, whichfork);
3990 		return -EFSCORRUPTED;
3991 	}
3992 
3993 	if (xfs_is_shutdown(mp))
3994 		return -EIO;
3995 
3996 	XFS_STATS_INC(mp, xs_blk_mapr);
3997 
3998 	error = xfs_iread_extents(NULL, ip, whichfork);
3999 	if (error)
4000 		return error;
4001 
4002 	if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got))
4003 		eof = true;
4004 	end = bno + len;
4005 	obno = bno;
4006 
4007 	while (bno < end && n < *nmap) {
4008 		/* Reading past eof, act as though there's a hole up to end. */
4009 		if (eof)
4010 			got.br_startoff = end;
4011 		if (got.br_startoff > bno) {
4012 			/* Reading in a hole.  */
4013 			mval->br_startoff = bno;
4014 			mval->br_startblock = HOLESTARTBLOCK;
4015 			mval->br_blockcount =
4016 				XFS_FILBLKS_MIN(len, got.br_startoff - bno);
4017 			mval->br_state = XFS_EXT_NORM;
4018 			bno += mval->br_blockcount;
4019 			len -= mval->br_blockcount;
4020 			mval++;
4021 			n++;
4022 			continue;
4023 		}
4024 
4025 		/* set up the extent map to return. */
4026 		xfs_bmapi_trim_map(mval, &got, &bno, len, obno, end, n, flags);
4027 		xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
4028 
4029 		/* If we're done, stop now. */
4030 		if (bno >= end || n >= *nmap)
4031 			break;
4032 
4033 		/* Else go on to the next record. */
4034 		if (!xfs_iext_next_extent(ifp, &icur, &got))
4035 			eof = true;
4036 	}
4037 	*nmap = n;
4038 	return 0;
4039 }
4040 
4041 /*
4042  * Add a delayed allocation extent to an inode. Blocks are reserved from the
4043  * global pool and the extent inserted into the inode in-core extent tree.
4044  *
4045  * On entry, got refers to the first extent beyond the offset of the extent to
4046  * allocate or eof is specified if no such extent exists. On return, got refers
4047  * to the extent record that was inserted to the inode fork.
4048  *
4049  * Note that the allocated extent may have been merged with contiguous extents
4050  * during insertion into the inode fork. Thus, got does not reflect the current
4051  * state of the inode fork on return. If necessary, the caller can use lastx to
4052  * look up the updated record in the inode fork.
4053  */
4054 int
4055 xfs_bmapi_reserve_delalloc(
4056 	struct xfs_inode	*ip,
4057 	int			whichfork,
4058 	xfs_fileoff_t		off,
4059 	xfs_filblks_t		len,
4060 	xfs_filblks_t		prealloc,
4061 	struct xfs_bmbt_irec	*got,
4062 	struct xfs_iext_cursor	*icur,
4063 	int			eof)
4064 {
4065 	struct xfs_mount	*mp = ip->i_mount;
4066 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
4067 	xfs_extlen_t		alen;
4068 	xfs_extlen_t		indlen;
4069 	int			error;
4070 	xfs_fileoff_t		aoff = off;
4071 
4072 	/*
4073 	 * Cap the alloc length. Keep track of prealloc so we know whether to
4074 	 * tag the inode before we return.
4075 	 */
4076 	alen = XFS_FILBLKS_MIN(len + prealloc, XFS_MAX_BMBT_EXTLEN);
4077 	if (!eof)
4078 		alen = XFS_FILBLKS_MIN(alen, got->br_startoff - aoff);
4079 	if (prealloc && alen >= len)
4080 		prealloc = alen - len;
4081 
4082 	/* Figure out the extent size, adjust alen */
4083 	if (whichfork == XFS_COW_FORK) {
4084 		struct xfs_bmbt_irec	prev;
4085 		xfs_extlen_t		extsz = xfs_get_cowextsz_hint(ip);
4086 
4087 		if (!xfs_iext_peek_prev_extent(ifp, icur, &prev))
4088 			prev.br_startoff = NULLFILEOFF;
4089 
4090 		error = xfs_bmap_extsize_align(mp, got, &prev, extsz, 0, eof,
4091 					       1, 0, &aoff, &alen);
4092 		ASSERT(!error);
4093 	}
4094 
4095 	/*
4096 	 * Make a transaction-less quota reservation for delayed allocation
4097 	 * blocks.  This number gets adjusted later.  We return if we haven't
4098 	 * allocated blocks already inside this loop.
4099 	 */
4100 	error = xfs_quota_reserve_blkres(ip, alen);
4101 	if (error)
4102 		return error;
4103 
4104 	/*
4105 	 * Split changing sb for alen and indlen since they could be coming
4106 	 * from different places.
4107 	 */
4108 	indlen = (xfs_extlen_t)xfs_bmap_worst_indlen(ip, alen);
4109 	ASSERT(indlen > 0);
4110 
4111 	error = xfs_mod_fdblocks(mp, -((int64_t)alen), false);
4112 	if (error)
4113 		goto out_unreserve_quota;
4114 
4115 	error = xfs_mod_fdblocks(mp, -((int64_t)indlen), false);
4116 	if (error)
4117 		goto out_unreserve_blocks;
4118 
4119 
4120 	ip->i_delayed_blks += alen;
4121 	xfs_mod_delalloc(ip->i_mount, alen + indlen);
4122 
4123 	got->br_startoff = aoff;
4124 	got->br_startblock = nullstartblock(indlen);
4125 	got->br_blockcount = alen;
4126 	got->br_state = XFS_EXT_NORM;
4127 
4128 	xfs_bmap_add_extent_hole_delay(ip, whichfork, icur, got);
4129 
4130 	/*
4131 	 * Tag the inode if blocks were preallocated. Note that COW fork
4132 	 * preallocation can occur at the start or end of the extent, even when
4133 	 * prealloc == 0, so we must also check the aligned offset and length.
4134 	 */
4135 	if (whichfork == XFS_DATA_FORK && prealloc)
4136 		xfs_inode_set_eofblocks_tag(ip);
4137 	if (whichfork == XFS_COW_FORK && (prealloc || aoff < off || alen > len))
4138 		xfs_inode_set_cowblocks_tag(ip);
4139 
4140 	return 0;
4141 
4142 out_unreserve_blocks:
4143 	xfs_mod_fdblocks(mp, alen, false);
4144 out_unreserve_quota:
4145 	if (XFS_IS_QUOTA_ON(mp))
4146 		xfs_quota_unreserve_blkres(ip, alen);
4147 	return error;
4148 }
4149 
4150 static int
4151 xfs_bmap_alloc_userdata(
4152 	struct xfs_bmalloca	*bma)
4153 {
4154 	struct xfs_mount	*mp = bma->ip->i_mount;
4155 	int			whichfork = xfs_bmapi_whichfork(bma->flags);
4156 	int			error;
4157 
4158 	/*
4159 	 * Set the data type being allocated. For the data fork, the first data
4160 	 * in the file is treated differently to all other allocations. For the
4161 	 * attribute fork, we only need to ensure the allocated range is not on
4162 	 * the busy list.
4163 	 */
4164 	bma->datatype = XFS_ALLOC_NOBUSY;
4165 	if (whichfork == XFS_DATA_FORK || whichfork == XFS_COW_FORK) {
4166 		bma->datatype |= XFS_ALLOC_USERDATA;
4167 		if (bma->offset == 0)
4168 			bma->datatype |= XFS_ALLOC_INITIAL_USER_DATA;
4169 
4170 		if (mp->m_dalign && bma->length >= mp->m_dalign) {
4171 			error = xfs_bmap_isaeof(bma, whichfork);
4172 			if (error)
4173 				return error;
4174 		}
4175 
4176 		if (XFS_IS_REALTIME_INODE(bma->ip))
4177 			return xfs_bmap_rtalloc(bma);
4178 	}
4179 
4180 	if (unlikely(XFS_TEST_ERROR(false, mp,
4181 			XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT)))
4182 		return xfs_bmap_exact_minlen_extent_alloc(bma);
4183 
4184 	return xfs_bmap_btalloc(bma);
4185 }
4186 
4187 static int
4188 xfs_bmapi_allocate(
4189 	struct xfs_bmalloca	*bma)
4190 {
4191 	struct xfs_mount	*mp = bma->ip->i_mount;
4192 	int			whichfork = xfs_bmapi_whichfork(bma->flags);
4193 	struct xfs_ifork	*ifp = xfs_ifork_ptr(bma->ip, whichfork);
4194 	int			tmp_logflags = 0;
4195 	int			error;
4196 
4197 	ASSERT(bma->length > 0);
4198 
4199 	/*
4200 	 * For the wasdelay case, we could also just allocate the stuff asked
4201 	 * for in this bmap call but that wouldn't be as good.
4202 	 */
4203 	if (bma->wasdel) {
4204 		bma->length = (xfs_extlen_t)bma->got.br_blockcount;
4205 		bma->offset = bma->got.br_startoff;
4206 		if (!xfs_iext_peek_prev_extent(ifp, &bma->icur, &bma->prev))
4207 			bma->prev.br_startoff = NULLFILEOFF;
4208 	} else {
4209 		bma->length = XFS_FILBLKS_MIN(bma->length, XFS_MAX_BMBT_EXTLEN);
4210 		if (!bma->eof)
4211 			bma->length = XFS_FILBLKS_MIN(bma->length,
4212 					bma->got.br_startoff - bma->offset);
4213 	}
4214 
4215 	if (bma->flags & XFS_BMAPI_CONTIG)
4216 		bma->minlen = bma->length;
4217 	else
4218 		bma->minlen = 1;
4219 
4220 	if (bma->flags & XFS_BMAPI_METADATA) {
4221 		if (unlikely(XFS_TEST_ERROR(false, mp,
4222 				XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT)))
4223 			error = xfs_bmap_exact_minlen_extent_alloc(bma);
4224 		else
4225 			error = xfs_bmap_btalloc(bma);
4226 	} else {
4227 		error = xfs_bmap_alloc_userdata(bma);
4228 	}
4229 	if (error || bma->blkno == NULLFSBLOCK)
4230 		return error;
4231 
4232 	if (bma->flags & XFS_BMAPI_ZERO) {
4233 		error = xfs_zero_extent(bma->ip, bma->blkno, bma->length);
4234 		if (error)
4235 			return error;
4236 	}
4237 
4238 	if (ifp->if_format == XFS_DINODE_FMT_BTREE && !bma->cur)
4239 		bma->cur = xfs_bmbt_init_cursor(mp, bma->tp, bma->ip, whichfork);
4240 	/*
4241 	 * Bump the number of extents we've allocated
4242 	 * in this call.
4243 	 */
4244 	bma->nallocs++;
4245 
4246 	if (bma->cur && bma->wasdel)
4247 		bma->cur->bc_flags |= XFS_BTREE_BMBT_WASDEL;
4248 
4249 	bma->got.br_startoff = bma->offset;
4250 	bma->got.br_startblock = bma->blkno;
4251 	bma->got.br_blockcount = bma->length;
4252 	bma->got.br_state = XFS_EXT_NORM;
4253 
4254 	if (bma->flags & XFS_BMAPI_PREALLOC)
4255 		bma->got.br_state = XFS_EXT_UNWRITTEN;
4256 
4257 	if (bma->wasdel)
4258 		error = xfs_bmap_add_extent_delay_real(bma, whichfork);
4259 	else
4260 		error = xfs_bmap_add_extent_hole_real(bma->tp, bma->ip,
4261 				whichfork, &bma->icur, &bma->cur, &bma->got,
4262 				&bma->logflags, bma->flags);
4263 
4264 	bma->logflags |= tmp_logflags;
4265 	if (error)
4266 		return error;
4267 
4268 	/*
4269 	 * Update our extent pointer, given that xfs_bmap_add_extent_delay_real
4270 	 * or xfs_bmap_add_extent_hole_real might have merged it into one of
4271 	 * the neighbouring ones.
4272 	 */
4273 	xfs_iext_get_extent(ifp, &bma->icur, &bma->got);
4274 
4275 	ASSERT(bma->got.br_startoff <= bma->offset);
4276 	ASSERT(bma->got.br_startoff + bma->got.br_blockcount >=
4277 	       bma->offset + bma->length);
4278 	ASSERT(bma->got.br_state == XFS_EXT_NORM ||
4279 	       bma->got.br_state == XFS_EXT_UNWRITTEN);
4280 	return 0;
4281 }
4282 
4283 STATIC int
4284 xfs_bmapi_convert_unwritten(
4285 	struct xfs_bmalloca	*bma,
4286 	struct xfs_bmbt_irec	*mval,
4287 	xfs_filblks_t		len,
4288 	uint32_t		flags)
4289 {
4290 	int			whichfork = xfs_bmapi_whichfork(flags);
4291 	struct xfs_ifork	*ifp = xfs_ifork_ptr(bma->ip, whichfork);
4292 	int			tmp_logflags = 0;
4293 	int			error;
4294 
4295 	/* check if we need to do unwritten->real conversion */
4296 	if (mval->br_state == XFS_EXT_UNWRITTEN &&
4297 	    (flags & XFS_BMAPI_PREALLOC))
4298 		return 0;
4299 
4300 	/* check if we need to do real->unwritten conversion */
4301 	if (mval->br_state == XFS_EXT_NORM &&
4302 	    (flags & (XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT)) !=
4303 			(XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT))
4304 		return 0;
4305 
4306 	/*
4307 	 * Modify (by adding) the state flag, if writing.
4308 	 */
4309 	ASSERT(mval->br_blockcount <= len);
4310 	if (ifp->if_format == XFS_DINODE_FMT_BTREE && !bma->cur) {
4311 		bma->cur = xfs_bmbt_init_cursor(bma->ip->i_mount, bma->tp,
4312 					bma->ip, whichfork);
4313 	}
4314 	mval->br_state = (mval->br_state == XFS_EXT_UNWRITTEN)
4315 				? XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
4316 
4317 	/*
4318 	 * Before insertion into the bmbt, zero the range being converted
4319 	 * if required.
4320 	 */
4321 	if (flags & XFS_BMAPI_ZERO) {
4322 		error = xfs_zero_extent(bma->ip, mval->br_startblock,
4323 					mval->br_blockcount);
4324 		if (error)
4325 			return error;
4326 	}
4327 
4328 	error = xfs_bmap_add_extent_unwritten_real(bma->tp, bma->ip, whichfork,
4329 			&bma->icur, &bma->cur, mval, &tmp_logflags);
4330 	/*
4331 	 * Log the inode core unconditionally in the unwritten extent conversion
4332 	 * path because the conversion might not have done so (e.g., if the
4333 	 * extent count hasn't changed). We need to make sure the inode is dirty
4334 	 * in the transaction for the sake of fsync(), even if nothing has
4335 	 * changed, because fsync() will not force the log for this transaction
4336 	 * unless it sees the inode pinned.
4337 	 *
4338 	 * Note: If we're only converting cow fork extents, there aren't
4339 	 * any on-disk updates to make, so we don't need to log anything.
4340 	 */
4341 	if (whichfork != XFS_COW_FORK)
4342 		bma->logflags |= tmp_logflags | XFS_ILOG_CORE;
4343 	if (error)
4344 		return error;
4345 
4346 	/*
4347 	 * Update our extent pointer, given that
4348 	 * xfs_bmap_add_extent_unwritten_real might have merged it into one
4349 	 * of the neighbouring ones.
4350 	 */
4351 	xfs_iext_get_extent(ifp, &bma->icur, &bma->got);
4352 
4353 	/*
4354 	 * We may have combined previously unwritten space with written space,
4355 	 * so generate another request.
4356 	 */
4357 	if (mval->br_blockcount < len)
4358 		return -EAGAIN;
4359 	return 0;
4360 }
4361 
4362 xfs_extlen_t
4363 xfs_bmapi_minleft(
4364 	struct xfs_trans	*tp,
4365 	struct xfs_inode	*ip,
4366 	int			fork)
4367 {
4368 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, fork);
4369 
4370 	if (tp && tp->t_highest_agno != NULLAGNUMBER)
4371 		return 0;
4372 	if (ifp->if_format != XFS_DINODE_FMT_BTREE)
4373 		return 1;
4374 	return be16_to_cpu(ifp->if_broot->bb_level) + 1;
4375 }
4376 
4377 /*
4378  * Log whatever the flags say, even if error.  Otherwise we might miss detecting
4379  * a case where the data is changed, there's an error, and it's not logged so we
4380  * don't shutdown when we should.  Don't bother logging extents/btree changes if
4381  * we converted to the other format.
4382  */
4383 static void
4384 xfs_bmapi_finish(
4385 	struct xfs_bmalloca	*bma,
4386 	int			whichfork,
4387 	int			error)
4388 {
4389 	struct xfs_ifork	*ifp = xfs_ifork_ptr(bma->ip, whichfork);
4390 
4391 	if ((bma->logflags & xfs_ilog_fext(whichfork)) &&
4392 	    ifp->if_format != XFS_DINODE_FMT_EXTENTS)
4393 		bma->logflags &= ~xfs_ilog_fext(whichfork);
4394 	else if ((bma->logflags & xfs_ilog_fbroot(whichfork)) &&
4395 		 ifp->if_format != XFS_DINODE_FMT_BTREE)
4396 		bma->logflags &= ~xfs_ilog_fbroot(whichfork);
4397 
4398 	if (bma->logflags)
4399 		xfs_trans_log_inode(bma->tp, bma->ip, bma->logflags);
4400 	if (bma->cur)
4401 		xfs_btree_del_cursor(bma->cur, error);
4402 }
4403 
4404 /*
4405  * Map file blocks to filesystem blocks, and allocate blocks or convert the
4406  * extent state if necessary.  Details behaviour is controlled by the flags
4407  * parameter.  Only allocates blocks from a single allocation group, to avoid
4408  * locking problems.
4409  */
4410 int
4411 xfs_bmapi_write(
4412 	struct xfs_trans	*tp,		/* transaction pointer */
4413 	struct xfs_inode	*ip,		/* incore inode */
4414 	xfs_fileoff_t		bno,		/* starting file offs. mapped */
4415 	xfs_filblks_t		len,		/* length to map in file */
4416 	uint32_t		flags,		/* XFS_BMAPI_... */
4417 	xfs_extlen_t		total,		/* total blocks needed */
4418 	struct xfs_bmbt_irec	*mval,		/* output: map values */
4419 	int			*nmap)		/* i/o: mval size/count */
4420 {
4421 	struct xfs_bmalloca	bma = {
4422 		.tp		= tp,
4423 		.ip		= ip,
4424 		.total		= total,
4425 	};
4426 	struct xfs_mount	*mp = ip->i_mount;
4427 	int			whichfork = xfs_bmapi_whichfork(flags);
4428 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
4429 	xfs_fileoff_t		end;		/* end of mapped file region */
4430 	bool			eof = false;	/* after the end of extents */
4431 	int			error;		/* error return */
4432 	int			n;		/* current extent index */
4433 	xfs_fileoff_t		obno;		/* old block number (offset) */
4434 
4435 #ifdef DEBUG
4436 	xfs_fileoff_t		orig_bno;	/* original block number value */
4437 	int			orig_flags;	/* original flags arg value */
4438 	xfs_filblks_t		orig_len;	/* original value of len arg */
4439 	struct xfs_bmbt_irec	*orig_mval;	/* original value of mval */
4440 	int			orig_nmap;	/* original value of *nmap */
4441 
4442 	orig_bno = bno;
4443 	orig_len = len;
4444 	orig_flags = flags;
4445 	orig_mval = mval;
4446 	orig_nmap = *nmap;
4447 #endif
4448 
4449 	ASSERT(*nmap >= 1);
4450 	ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
4451 	ASSERT(tp != NULL);
4452 	ASSERT(len > 0);
4453 	ASSERT(ifp->if_format != XFS_DINODE_FMT_LOCAL);
4454 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
4455 	ASSERT(!(flags & XFS_BMAPI_REMAP));
4456 
4457 	/* zeroing is for currently only for data extents, not metadata */
4458 	ASSERT((flags & (XFS_BMAPI_METADATA | XFS_BMAPI_ZERO)) !=
4459 			(XFS_BMAPI_METADATA | XFS_BMAPI_ZERO));
4460 	/*
4461 	 * we can allocate unwritten extents or pre-zero allocated blocks,
4462 	 * but it makes no sense to do both at once. This would result in
4463 	 * zeroing the unwritten extent twice, but it still being an
4464 	 * unwritten extent....
4465 	 */
4466 	ASSERT((flags & (XFS_BMAPI_PREALLOC | XFS_BMAPI_ZERO)) !=
4467 			(XFS_BMAPI_PREALLOC | XFS_BMAPI_ZERO));
4468 
4469 	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
4470 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
4471 		xfs_bmap_mark_sick(ip, whichfork);
4472 		return -EFSCORRUPTED;
4473 	}
4474 
4475 	if (xfs_is_shutdown(mp))
4476 		return -EIO;
4477 
4478 	XFS_STATS_INC(mp, xs_blk_mapw);
4479 
4480 	error = xfs_iread_extents(tp, ip, whichfork);
4481 	if (error)
4482 		goto error0;
4483 
4484 	if (!xfs_iext_lookup_extent(ip, ifp, bno, &bma.icur, &bma.got))
4485 		eof = true;
4486 	if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
4487 		bma.prev.br_startoff = NULLFILEOFF;
4488 	bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
4489 
4490 	n = 0;
4491 	end = bno + len;
4492 	obno = bno;
4493 	while (bno < end && n < *nmap) {
4494 		bool			need_alloc = false, wasdelay = false;
4495 
4496 		/* in hole or beyond EOF? */
4497 		if (eof || bma.got.br_startoff > bno) {
4498 			/*
4499 			 * CoW fork conversions should /never/ hit EOF or
4500 			 * holes.  There should always be something for us
4501 			 * to work on.
4502 			 */
4503 			ASSERT(!((flags & XFS_BMAPI_CONVERT) &&
4504 			         (flags & XFS_BMAPI_COWFORK)));
4505 
4506 			need_alloc = true;
4507 		} else if (isnullstartblock(bma.got.br_startblock)) {
4508 			wasdelay = true;
4509 		}
4510 
4511 		/*
4512 		 * First, deal with the hole before the allocated space
4513 		 * that we found, if any.
4514 		 */
4515 		if (need_alloc || wasdelay) {
4516 			bma.eof = eof;
4517 			bma.conv = !!(flags & XFS_BMAPI_CONVERT);
4518 			bma.wasdel = wasdelay;
4519 			bma.offset = bno;
4520 			bma.flags = flags;
4521 
4522 			/*
4523 			 * There's a 32/64 bit type mismatch between the
4524 			 * allocation length request (which can be 64 bits in
4525 			 * length) and the bma length request, which is
4526 			 * xfs_extlen_t and therefore 32 bits. Hence we have to
4527 			 * check for 32-bit overflows and handle them here.
4528 			 */
4529 			if (len > (xfs_filblks_t)XFS_MAX_BMBT_EXTLEN)
4530 				bma.length = XFS_MAX_BMBT_EXTLEN;
4531 			else
4532 				bma.length = len;
4533 
4534 			ASSERT(len > 0);
4535 			ASSERT(bma.length > 0);
4536 			error = xfs_bmapi_allocate(&bma);
4537 			if (error)
4538 				goto error0;
4539 			if (bma.blkno == NULLFSBLOCK)
4540 				break;
4541 
4542 			/*
4543 			 * If this is a CoW allocation, record the data in
4544 			 * the refcount btree for orphan recovery.
4545 			 */
4546 			if (whichfork == XFS_COW_FORK)
4547 				xfs_refcount_alloc_cow_extent(tp, bma.blkno,
4548 						bma.length);
4549 		}
4550 
4551 		/* Deal with the allocated space we found.  */
4552 		xfs_bmapi_trim_map(mval, &bma.got, &bno, len, obno,
4553 							end, n, flags);
4554 
4555 		/* Execute unwritten extent conversion if necessary */
4556 		error = xfs_bmapi_convert_unwritten(&bma, mval, len, flags);
4557 		if (error == -EAGAIN)
4558 			continue;
4559 		if (error)
4560 			goto error0;
4561 
4562 		/* update the extent map to return */
4563 		xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
4564 
4565 		/*
4566 		 * If we're done, stop now.  Stop when we've allocated
4567 		 * XFS_BMAP_MAX_NMAP extents no matter what.  Otherwise
4568 		 * the transaction may get too big.
4569 		 */
4570 		if (bno >= end || n >= *nmap || bma.nallocs >= *nmap)
4571 			break;
4572 
4573 		/* Else go on to the next record. */
4574 		bma.prev = bma.got;
4575 		if (!xfs_iext_next_extent(ifp, &bma.icur, &bma.got))
4576 			eof = true;
4577 	}
4578 	*nmap = n;
4579 
4580 	error = xfs_bmap_btree_to_extents(tp, ip, bma.cur, &bma.logflags,
4581 			whichfork);
4582 	if (error)
4583 		goto error0;
4584 
4585 	ASSERT(ifp->if_format != XFS_DINODE_FMT_BTREE ||
4586 	       ifp->if_nextents > XFS_IFORK_MAXEXT(ip, whichfork));
4587 	xfs_bmapi_finish(&bma, whichfork, 0);
4588 	xfs_bmap_validate_ret(orig_bno, orig_len, orig_flags, orig_mval,
4589 		orig_nmap, *nmap);
4590 	return 0;
4591 error0:
4592 	xfs_bmapi_finish(&bma, whichfork, error);
4593 	return error;
4594 }
4595 
4596 /*
4597  * Convert an existing delalloc extent to real blocks based on file offset. This
4598  * attempts to allocate the entire delalloc extent and may require multiple
4599  * invocations to allocate the target offset if a large enough physical extent
4600  * is not available.
4601  */
4602 int
4603 xfs_bmapi_convert_delalloc(
4604 	struct xfs_inode	*ip,
4605 	int			whichfork,
4606 	xfs_off_t		offset,
4607 	struct iomap		*iomap,
4608 	unsigned int		*seq)
4609 {
4610 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
4611 	struct xfs_mount	*mp = ip->i_mount;
4612 	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
4613 	struct xfs_bmalloca	bma = { NULL };
4614 	uint16_t		flags = 0;
4615 	struct xfs_trans	*tp;
4616 	int			error;
4617 
4618 	if (whichfork == XFS_COW_FORK)
4619 		flags |= IOMAP_F_SHARED;
4620 
4621 	/*
4622 	 * Space for the extent and indirect blocks was reserved when the
4623 	 * delalloc extent was created so there's no need to do so here.
4624 	 */
4625 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0,
4626 				XFS_TRANS_RESERVE, &tp);
4627 	if (error)
4628 		return error;
4629 
4630 	xfs_ilock(ip, XFS_ILOCK_EXCL);
4631 	xfs_trans_ijoin(tp, ip, 0);
4632 
4633 	error = xfs_iext_count_may_overflow(ip, whichfork,
4634 			XFS_IEXT_ADD_NOSPLIT_CNT);
4635 	if (error == -EFBIG)
4636 		error = xfs_iext_count_upgrade(tp, ip,
4637 				XFS_IEXT_ADD_NOSPLIT_CNT);
4638 	if (error)
4639 		goto out_trans_cancel;
4640 
4641 	if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &bma.icur, &bma.got) ||
4642 	    bma.got.br_startoff > offset_fsb) {
4643 		/*
4644 		 * No extent found in the range we are trying to convert.  This
4645 		 * should only happen for the COW fork, where another thread
4646 		 * might have moved the extent to the data fork in the meantime.
4647 		 */
4648 		WARN_ON_ONCE(whichfork != XFS_COW_FORK);
4649 		error = -EAGAIN;
4650 		goto out_trans_cancel;
4651 	}
4652 
4653 	/*
4654 	 * If we find a real extent here we raced with another thread converting
4655 	 * the extent.  Just return the real extent at this offset.
4656 	 */
4657 	if (!isnullstartblock(bma.got.br_startblock)) {
4658 		xfs_bmbt_to_iomap(ip, iomap, &bma.got, 0, flags,
4659 				xfs_iomap_inode_sequence(ip, flags));
4660 		*seq = READ_ONCE(ifp->if_seq);
4661 		goto out_trans_cancel;
4662 	}
4663 
4664 	bma.tp = tp;
4665 	bma.ip = ip;
4666 	bma.wasdel = true;
4667 	bma.offset = bma.got.br_startoff;
4668 	bma.length = max_t(xfs_filblks_t, bma.got.br_blockcount,
4669 			XFS_MAX_BMBT_EXTLEN);
4670 	bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
4671 
4672 	/*
4673 	 * When we're converting the delalloc reservations backing dirty pages
4674 	 * in the page cache, we must be careful about how we create the new
4675 	 * extents:
4676 	 *
4677 	 * New CoW fork extents are created unwritten, turned into real extents
4678 	 * when we're about to write the data to disk, and mapped into the data
4679 	 * fork after the write finishes.  End of story.
4680 	 *
4681 	 * New data fork extents must be mapped in as unwritten and converted
4682 	 * to real extents after the write succeeds to avoid exposing stale
4683 	 * disk contents if we crash.
4684 	 */
4685 	bma.flags = XFS_BMAPI_PREALLOC;
4686 	if (whichfork == XFS_COW_FORK)
4687 		bma.flags |= XFS_BMAPI_COWFORK;
4688 
4689 	if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
4690 		bma.prev.br_startoff = NULLFILEOFF;
4691 
4692 	error = xfs_bmapi_allocate(&bma);
4693 	if (error)
4694 		goto out_finish;
4695 
4696 	error = -ENOSPC;
4697 	if (WARN_ON_ONCE(bma.blkno == NULLFSBLOCK))
4698 		goto out_finish;
4699 	if (WARN_ON_ONCE(!xfs_valid_startblock(ip, bma.got.br_startblock))) {
4700 		xfs_bmap_mark_sick(ip, whichfork);
4701 		error = -EFSCORRUPTED;
4702 		goto out_finish;
4703 	}
4704 
4705 	XFS_STATS_ADD(mp, xs_xstrat_bytes, XFS_FSB_TO_B(mp, bma.length));
4706 	XFS_STATS_INC(mp, xs_xstrat_quick);
4707 
4708 	ASSERT(!isnullstartblock(bma.got.br_startblock));
4709 	xfs_bmbt_to_iomap(ip, iomap, &bma.got, 0, flags,
4710 				xfs_iomap_inode_sequence(ip, flags));
4711 	*seq = READ_ONCE(ifp->if_seq);
4712 
4713 	if (whichfork == XFS_COW_FORK)
4714 		xfs_refcount_alloc_cow_extent(tp, bma.blkno, bma.length);
4715 
4716 	error = xfs_bmap_btree_to_extents(tp, ip, bma.cur, &bma.logflags,
4717 			whichfork);
4718 	if (error)
4719 		goto out_finish;
4720 
4721 	xfs_bmapi_finish(&bma, whichfork, 0);
4722 	error = xfs_trans_commit(tp);
4723 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
4724 	return error;
4725 
4726 out_finish:
4727 	xfs_bmapi_finish(&bma, whichfork, error);
4728 out_trans_cancel:
4729 	xfs_trans_cancel(tp);
4730 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
4731 	return error;
4732 }
4733 
4734 int
4735 xfs_bmapi_remap(
4736 	struct xfs_trans	*tp,
4737 	struct xfs_inode	*ip,
4738 	xfs_fileoff_t		bno,
4739 	xfs_filblks_t		len,
4740 	xfs_fsblock_t		startblock,
4741 	uint32_t		flags)
4742 {
4743 	struct xfs_mount	*mp = ip->i_mount;
4744 	struct xfs_ifork	*ifp;
4745 	struct xfs_btree_cur	*cur = NULL;
4746 	struct xfs_bmbt_irec	got;
4747 	struct xfs_iext_cursor	icur;
4748 	int			whichfork = xfs_bmapi_whichfork(flags);
4749 	int			logflags = 0, error;
4750 
4751 	ifp = xfs_ifork_ptr(ip, whichfork);
4752 	ASSERT(len > 0);
4753 	ASSERT(len <= (xfs_filblks_t)XFS_MAX_BMBT_EXTLEN);
4754 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
4755 	ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC |
4756 			   XFS_BMAPI_NORMAP)));
4757 	ASSERT((flags & (XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC)) !=
4758 			(XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC));
4759 
4760 	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
4761 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
4762 		xfs_bmap_mark_sick(ip, whichfork);
4763 		return -EFSCORRUPTED;
4764 	}
4765 
4766 	if (xfs_is_shutdown(mp))
4767 		return -EIO;
4768 
4769 	error = xfs_iread_extents(tp, ip, whichfork);
4770 	if (error)
4771 		return error;
4772 
4773 	if (xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
4774 		/* make sure we only reflink into a hole. */
4775 		ASSERT(got.br_startoff > bno);
4776 		ASSERT(got.br_startoff - bno >= len);
4777 	}
4778 
4779 	ip->i_nblocks += len;
4780 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
4781 
4782 	if (ifp->if_format == XFS_DINODE_FMT_BTREE)
4783 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
4784 
4785 	got.br_startoff = bno;
4786 	got.br_startblock = startblock;
4787 	got.br_blockcount = len;
4788 	if (flags & XFS_BMAPI_PREALLOC)
4789 		got.br_state = XFS_EXT_UNWRITTEN;
4790 	else
4791 		got.br_state = XFS_EXT_NORM;
4792 
4793 	error = xfs_bmap_add_extent_hole_real(tp, ip, whichfork, &icur,
4794 			&cur, &got, &logflags, flags);
4795 	if (error)
4796 		goto error0;
4797 
4798 	error = xfs_bmap_btree_to_extents(tp, ip, cur, &logflags, whichfork);
4799 
4800 error0:
4801 	if (ip->i_df.if_format != XFS_DINODE_FMT_EXTENTS)
4802 		logflags &= ~XFS_ILOG_DEXT;
4803 	else if (ip->i_df.if_format != XFS_DINODE_FMT_BTREE)
4804 		logflags &= ~XFS_ILOG_DBROOT;
4805 
4806 	if (logflags)
4807 		xfs_trans_log_inode(tp, ip, logflags);
4808 	if (cur)
4809 		xfs_btree_del_cursor(cur, error);
4810 	return error;
4811 }
4812 
4813 /*
4814  * When a delalloc extent is split (e.g., due to a hole punch), the original
4815  * indlen reservation must be shared across the two new extents that are left
4816  * behind.
4817  *
4818  * Given the original reservation and the worst case indlen for the two new
4819  * extents (as calculated by xfs_bmap_worst_indlen()), split the original
4820  * reservation fairly across the two new extents. If necessary, steal available
4821  * blocks from a deleted extent to make up a reservation deficiency (e.g., if
4822  * ores == 1). The number of stolen blocks is returned. The availability and
4823  * subsequent accounting of stolen blocks is the responsibility of the caller.
4824  */
4825 static xfs_filblks_t
4826 xfs_bmap_split_indlen(
4827 	xfs_filblks_t			ores,		/* original res. */
4828 	xfs_filblks_t			*indlen1,	/* ext1 worst indlen */
4829 	xfs_filblks_t			*indlen2,	/* ext2 worst indlen */
4830 	xfs_filblks_t			avail)		/* stealable blocks */
4831 {
4832 	xfs_filblks_t			len1 = *indlen1;
4833 	xfs_filblks_t			len2 = *indlen2;
4834 	xfs_filblks_t			nres = len1 + len2; /* new total res. */
4835 	xfs_filblks_t			stolen = 0;
4836 	xfs_filblks_t			resfactor;
4837 
4838 	/*
4839 	 * Steal as many blocks as we can to try and satisfy the worst case
4840 	 * indlen for both new extents.
4841 	 */
4842 	if (ores < nres && avail)
4843 		stolen = XFS_FILBLKS_MIN(nres - ores, avail);
4844 	ores += stolen;
4845 
4846 	 /* nothing else to do if we've satisfied the new reservation */
4847 	if (ores >= nres)
4848 		return stolen;
4849 
4850 	/*
4851 	 * We can't meet the total required reservation for the two extents.
4852 	 * Calculate the percent of the overall shortage between both extents
4853 	 * and apply this percentage to each of the requested indlen values.
4854 	 * This distributes the shortage fairly and reduces the chances that one
4855 	 * of the two extents is left with nothing when extents are repeatedly
4856 	 * split.
4857 	 */
4858 	resfactor = (ores * 100);
4859 	do_div(resfactor, nres);
4860 	len1 *= resfactor;
4861 	do_div(len1, 100);
4862 	len2 *= resfactor;
4863 	do_div(len2, 100);
4864 	ASSERT(len1 + len2 <= ores);
4865 	ASSERT(len1 < *indlen1 && len2 < *indlen2);
4866 
4867 	/*
4868 	 * Hand out the remainder to each extent. If one of the two reservations
4869 	 * is zero, we want to make sure that one gets a block first. The loop
4870 	 * below starts with len1, so hand len2 a block right off the bat if it
4871 	 * is zero.
4872 	 */
4873 	ores -= (len1 + len2);
4874 	ASSERT((*indlen1 - len1) + (*indlen2 - len2) >= ores);
4875 	if (ores && !len2 && *indlen2) {
4876 		len2++;
4877 		ores--;
4878 	}
4879 	while (ores) {
4880 		if (len1 < *indlen1) {
4881 			len1++;
4882 			ores--;
4883 		}
4884 		if (!ores)
4885 			break;
4886 		if (len2 < *indlen2) {
4887 			len2++;
4888 			ores--;
4889 		}
4890 	}
4891 
4892 	*indlen1 = len1;
4893 	*indlen2 = len2;
4894 
4895 	return stolen;
4896 }
4897 
4898 int
4899 xfs_bmap_del_extent_delay(
4900 	struct xfs_inode	*ip,
4901 	int			whichfork,
4902 	struct xfs_iext_cursor	*icur,
4903 	struct xfs_bmbt_irec	*got,
4904 	struct xfs_bmbt_irec	*del)
4905 {
4906 	struct xfs_mount	*mp = ip->i_mount;
4907 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
4908 	struct xfs_bmbt_irec	new;
4909 	int64_t			da_old, da_new, da_diff = 0;
4910 	xfs_fileoff_t		del_endoff, got_endoff;
4911 	xfs_filblks_t		got_indlen, new_indlen, stolen;
4912 	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
4913 	int			error = 0;
4914 	bool			isrt;
4915 
4916 	XFS_STATS_INC(mp, xs_del_exlist);
4917 
4918 	isrt = xfs_ifork_is_realtime(ip, whichfork);
4919 	del_endoff = del->br_startoff + del->br_blockcount;
4920 	got_endoff = got->br_startoff + got->br_blockcount;
4921 	da_old = startblockval(got->br_startblock);
4922 	da_new = 0;
4923 
4924 	ASSERT(del->br_blockcount > 0);
4925 	ASSERT(got->br_startoff <= del->br_startoff);
4926 	ASSERT(got_endoff >= del_endoff);
4927 
4928 	if (isrt)
4929 		xfs_mod_frextents(mp, xfs_rtb_to_rtx(mp, del->br_blockcount));
4930 
4931 	/*
4932 	 * Update the inode delalloc counter now and wait to update the
4933 	 * sb counters as we might have to borrow some blocks for the
4934 	 * indirect block accounting.
4935 	 */
4936 	ASSERT(!isrt);
4937 	error = xfs_quota_unreserve_blkres(ip, del->br_blockcount);
4938 	if (error)
4939 		return error;
4940 	ip->i_delayed_blks -= del->br_blockcount;
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 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip,
4962 				got->br_blockcount), da_old);
4963 		got->br_startblock = nullstartblock((int)da_new);
4964 		xfs_iext_update_extent(ip, state, icur, got);
4965 		break;
4966 	case BMAP_RIGHT_FILLING:
4967 		/*
4968 		 * Deleting the last part of the extent.
4969 		 */
4970 		got->br_blockcount = got->br_blockcount - del->br_blockcount;
4971 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip,
4972 				got->br_blockcount), da_old);
4973 		got->br_startblock = nullstartblock((int)da_new);
4974 		xfs_iext_update_extent(ip, state, icur, got);
4975 		break;
4976 	case 0:
4977 		/*
4978 		 * Deleting the middle of the extent.
4979 		 *
4980 		 * Distribute the original indlen reservation across the two new
4981 		 * extents.  Steal blocks from the deleted extent if necessary.
4982 		 * Stealing blocks simply fudges the fdblocks accounting below.
4983 		 * Warn if either of the new indlen reservations is zero as this
4984 		 * can lead to delalloc problems.
4985 		 */
4986 		got->br_blockcount = del->br_startoff - got->br_startoff;
4987 		got_indlen = xfs_bmap_worst_indlen(ip, got->br_blockcount);
4988 
4989 		new.br_blockcount = got_endoff - del_endoff;
4990 		new_indlen = xfs_bmap_worst_indlen(ip, new.br_blockcount);
4991 
4992 		WARN_ON_ONCE(!got_indlen || !new_indlen);
4993 		stolen = xfs_bmap_split_indlen(da_old, &got_indlen, &new_indlen,
4994 						       del->br_blockcount);
4995 
4996 		got->br_startblock = nullstartblock((int)got_indlen);
4997 
4998 		new.br_startoff = del_endoff;
4999 		new.br_state = got->br_state;
5000 		new.br_startblock = nullstartblock((int)new_indlen);
5001 
5002 		xfs_iext_update_extent(ip, state, icur, got);
5003 		xfs_iext_next(ifp, icur);
5004 		xfs_iext_insert(ip, icur, &new, state);
5005 
5006 		da_new = got_indlen + new_indlen - stolen;
5007 		del->br_blockcount -= stolen;
5008 		break;
5009 	}
5010 
5011 	ASSERT(da_old >= da_new);
5012 	da_diff = da_old - da_new;
5013 	if (!isrt)
5014 		da_diff += del->br_blockcount;
5015 	if (da_diff) {
5016 		xfs_mod_fdblocks(mp, da_diff, false);
5017 		xfs_mod_delalloc(mp, -da_diff);
5018 	}
5019 	return error;
5020 }
5021 
5022 void
5023 xfs_bmap_del_extent_cow(
5024 	struct xfs_inode	*ip,
5025 	struct xfs_iext_cursor	*icur,
5026 	struct xfs_bmbt_irec	*got,
5027 	struct xfs_bmbt_irec	*del)
5028 {
5029 	struct xfs_mount	*mp = ip->i_mount;
5030 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, XFS_COW_FORK);
5031 	struct xfs_bmbt_irec	new;
5032 	xfs_fileoff_t		del_endoff, got_endoff;
5033 	uint32_t		state = BMAP_COWFORK;
5034 
5035 	XFS_STATS_INC(mp, xs_del_exlist);
5036 
5037 	del_endoff = del->br_startoff + del->br_blockcount;
5038 	got_endoff = got->br_startoff + got->br_blockcount;
5039 
5040 	ASSERT(del->br_blockcount > 0);
5041 	ASSERT(got->br_startoff <= del->br_startoff);
5042 	ASSERT(got_endoff >= del_endoff);
5043 	ASSERT(!isnullstartblock(got->br_startblock));
5044 
5045 	if (got->br_startoff == del->br_startoff)
5046 		state |= BMAP_LEFT_FILLING;
5047 	if (got_endoff == del_endoff)
5048 		state |= BMAP_RIGHT_FILLING;
5049 
5050 	switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
5051 	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
5052 		/*
5053 		 * Matches the whole extent.  Delete the entry.
5054 		 */
5055 		xfs_iext_remove(ip, icur, state);
5056 		xfs_iext_prev(ifp, icur);
5057 		break;
5058 	case BMAP_LEFT_FILLING:
5059 		/*
5060 		 * Deleting the first part of the extent.
5061 		 */
5062 		got->br_startoff = del_endoff;
5063 		got->br_blockcount -= del->br_blockcount;
5064 		got->br_startblock = del->br_startblock + del->br_blockcount;
5065 		xfs_iext_update_extent(ip, state, icur, got);
5066 		break;
5067 	case BMAP_RIGHT_FILLING:
5068 		/*
5069 		 * Deleting the last part of the extent.
5070 		 */
5071 		got->br_blockcount -= del->br_blockcount;
5072 		xfs_iext_update_extent(ip, state, icur, got);
5073 		break;
5074 	case 0:
5075 		/*
5076 		 * Deleting the middle of the extent.
5077 		 */
5078 		got->br_blockcount = del->br_startoff - got->br_startoff;
5079 
5080 		new.br_startoff = del_endoff;
5081 		new.br_blockcount = got_endoff - del_endoff;
5082 		new.br_state = got->br_state;
5083 		new.br_startblock = del->br_startblock + del->br_blockcount;
5084 
5085 		xfs_iext_update_extent(ip, state, icur, got);
5086 		xfs_iext_next(ifp, icur);
5087 		xfs_iext_insert(ip, icur, &new, state);
5088 		break;
5089 	}
5090 	ip->i_delayed_blks -= del->br_blockcount;
5091 }
5092 
5093 /*
5094  * Called by xfs_bmapi to update file extent records and the btree
5095  * after removing space.
5096  */
5097 STATIC int				/* error */
5098 xfs_bmap_del_extent_real(
5099 	xfs_inode_t		*ip,	/* incore inode pointer */
5100 	xfs_trans_t		*tp,	/* current transaction pointer */
5101 	struct xfs_iext_cursor	*icur,
5102 	struct xfs_btree_cur	*cur,	/* if null, not a btree */
5103 	xfs_bmbt_irec_t		*del,	/* data to remove from extents */
5104 	int			*logflagsp, /* inode logging flags */
5105 	int			whichfork, /* data or attr fork */
5106 	uint32_t		bflags)	/* bmapi flags */
5107 {
5108 	xfs_fsblock_t		del_endblock=0;	/* first block past del */
5109 	xfs_fileoff_t		del_endoff;	/* first offset past del */
5110 	int			do_fx;	/* free extent at end of routine */
5111 	int			error;	/* error return value */
5112 	struct xfs_bmbt_irec	got;	/* current extent entry */
5113 	xfs_fileoff_t		got_endoff;	/* first offset past got */
5114 	int			i;	/* temp state */
5115 	struct xfs_ifork	*ifp;	/* inode fork pointer */
5116 	xfs_mount_t		*mp;	/* mount structure */
5117 	xfs_filblks_t		nblks;	/* quota/sb block count */
5118 	xfs_bmbt_irec_t		new;	/* new record to be inserted */
5119 	/* REFERENCED */
5120 	uint			qfield;	/* quota field to update */
5121 	uint32_t		state = xfs_bmap_fork_to_state(whichfork);
5122 	struct xfs_bmbt_irec	old;
5123 
5124 	*logflagsp = 0;
5125 
5126 	mp = ip->i_mount;
5127 	XFS_STATS_INC(mp, xs_del_exlist);
5128 
5129 	ifp = xfs_ifork_ptr(ip, whichfork);
5130 	ASSERT(del->br_blockcount > 0);
5131 	xfs_iext_get_extent(ifp, icur, &got);
5132 	ASSERT(got.br_startoff <= del->br_startoff);
5133 	del_endoff = del->br_startoff + del->br_blockcount;
5134 	got_endoff = got.br_startoff + got.br_blockcount;
5135 	ASSERT(got_endoff >= del_endoff);
5136 	ASSERT(!isnullstartblock(got.br_startblock));
5137 	qfield = 0;
5138 
5139 	/*
5140 	 * If it's the case where the directory code is running with no block
5141 	 * reservation, and the deleted block is in the middle of its extent,
5142 	 * and the resulting insert of an extent would cause transformation to
5143 	 * btree format, then reject it.  The calling code will then swap blocks
5144 	 * around instead.  We have to do this now, rather than waiting for the
5145 	 * conversion to btree format, since the transaction will be dirty then.
5146 	 */
5147 	if (tp->t_blk_res == 0 &&
5148 	    ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
5149 	    ifp->if_nextents >= XFS_IFORK_MAXEXT(ip, whichfork) &&
5150 	    del->br_startoff > got.br_startoff && del_endoff < got_endoff)
5151 		return -ENOSPC;
5152 
5153 	*logflagsp = XFS_ILOG_CORE;
5154 	if (xfs_ifork_is_realtime(ip, whichfork)) {
5155 		if (!(bflags & XFS_BMAPI_REMAP)) {
5156 			error = xfs_rtfree_blocks(tp, del->br_startblock,
5157 					del->br_blockcount);
5158 			if (error)
5159 				return error;
5160 		}
5161 
5162 		do_fx = 0;
5163 		qfield = XFS_TRANS_DQ_RTBCOUNT;
5164 	} else {
5165 		do_fx = 1;
5166 		qfield = XFS_TRANS_DQ_BCOUNT;
5167 	}
5168 	nblks = del->br_blockcount;
5169 
5170 	del_endblock = del->br_startblock + del->br_blockcount;
5171 	if (cur) {
5172 		error = xfs_bmbt_lookup_eq(cur, &got, &i);
5173 		if (error)
5174 			return error;
5175 		if (XFS_IS_CORRUPT(mp, i != 1)) {
5176 			xfs_btree_mark_sick(cur);
5177 			return -EFSCORRUPTED;
5178 		}
5179 	}
5180 
5181 	if (got.br_startoff == del->br_startoff)
5182 		state |= BMAP_LEFT_FILLING;
5183 	if (got_endoff == del_endoff)
5184 		state |= BMAP_RIGHT_FILLING;
5185 
5186 	switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
5187 	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
5188 		/*
5189 		 * Matches the whole extent.  Delete the entry.
5190 		 */
5191 		xfs_iext_remove(ip, icur, state);
5192 		xfs_iext_prev(ifp, icur);
5193 		ifp->if_nextents--;
5194 
5195 		*logflagsp |= XFS_ILOG_CORE;
5196 		if (!cur) {
5197 			*logflagsp |= xfs_ilog_fext(whichfork);
5198 			break;
5199 		}
5200 		if ((error = xfs_btree_delete(cur, &i)))
5201 			return error;
5202 		if (XFS_IS_CORRUPT(mp, i != 1)) {
5203 			xfs_btree_mark_sick(cur);
5204 			return -EFSCORRUPTED;
5205 		}
5206 		break;
5207 	case BMAP_LEFT_FILLING:
5208 		/*
5209 		 * Deleting the first part of the extent.
5210 		 */
5211 		got.br_startoff = del_endoff;
5212 		got.br_startblock = del_endblock;
5213 		got.br_blockcount -= del->br_blockcount;
5214 		xfs_iext_update_extent(ip, state, icur, &got);
5215 		if (!cur) {
5216 			*logflagsp |= xfs_ilog_fext(whichfork);
5217 			break;
5218 		}
5219 		error = xfs_bmbt_update(cur, &got);
5220 		if (error)
5221 			return error;
5222 		break;
5223 	case BMAP_RIGHT_FILLING:
5224 		/*
5225 		 * Deleting the last part of the extent.
5226 		 */
5227 		got.br_blockcount -= del->br_blockcount;
5228 		xfs_iext_update_extent(ip, state, icur, &got);
5229 		if (!cur) {
5230 			*logflagsp |= xfs_ilog_fext(whichfork);
5231 			break;
5232 		}
5233 		error = xfs_bmbt_update(cur, &got);
5234 		if (error)
5235 			return error;
5236 		break;
5237 	case 0:
5238 		/*
5239 		 * Deleting the middle of the extent.
5240 		 */
5241 
5242 		old = got;
5243 
5244 		got.br_blockcount = del->br_startoff - got.br_startoff;
5245 		xfs_iext_update_extent(ip, state, icur, &got);
5246 
5247 		new.br_startoff = del_endoff;
5248 		new.br_blockcount = got_endoff - del_endoff;
5249 		new.br_state = got.br_state;
5250 		new.br_startblock = del_endblock;
5251 
5252 		*logflagsp |= XFS_ILOG_CORE;
5253 		if (cur) {
5254 			error = xfs_bmbt_update(cur, &got);
5255 			if (error)
5256 				return error;
5257 			error = xfs_btree_increment(cur, 0, &i);
5258 			if (error)
5259 				return error;
5260 			cur->bc_rec.b = new;
5261 			error = xfs_btree_insert(cur, &i);
5262 			if (error && error != -ENOSPC)
5263 				return error;
5264 			/*
5265 			 * If get no-space back from btree insert, it tried a
5266 			 * split, and we have a zero block reservation.  Fix up
5267 			 * our state and return the error.
5268 			 */
5269 			if (error == -ENOSPC) {
5270 				/*
5271 				 * Reset the cursor, don't trust it after any
5272 				 * insert operation.
5273 				 */
5274 				error = xfs_bmbt_lookup_eq(cur, &got, &i);
5275 				if (error)
5276 					return error;
5277 				if (XFS_IS_CORRUPT(mp, i != 1)) {
5278 					xfs_btree_mark_sick(cur);
5279 					return -EFSCORRUPTED;
5280 				}
5281 				/*
5282 				 * Update the btree record back
5283 				 * to the original value.
5284 				 */
5285 				error = xfs_bmbt_update(cur, &old);
5286 				if (error)
5287 					return error;
5288 				/*
5289 				 * Reset the extent record back
5290 				 * to the original value.
5291 				 */
5292 				xfs_iext_update_extent(ip, state, icur, &old);
5293 				*logflagsp = 0;
5294 				return -ENOSPC;
5295 			}
5296 			if (XFS_IS_CORRUPT(mp, i != 1)) {
5297 				xfs_btree_mark_sick(cur);
5298 				return -EFSCORRUPTED;
5299 			}
5300 		} else
5301 			*logflagsp |= xfs_ilog_fext(whichfork);
5302 
5303 		ifp->if_nextents++;
5304 		xfs_iext_next(ifp, icur);
5305 		xfs_iext_insert(ip, icur, &new, state);
5306 		break;
5307 	}
5308 
5309 	/* remove reverse mapping */
5310 	xfs_rmap_unmap_extent(tp, ip, whichfork, del);
5311 
5312 	/*
5313 	 * If we need to, add to list of extents to delete.
5314 	 */
5315 	if (do_fx && !(bflags & XFS_BMAPI_REMAP)) {
5316 		if (xfs_is_reflink_inode(ip) && whichfork == XFS_DATA_FORK) {
5317 			xfs_refcount_decrease_extent(tp, del);
5318 		} else {
5319 			error = xfs_free_extent_later(tp, del->br_startblock,
5320 					del->br_blockcount, NULL,
5321 					XFS_AG_RESV_NONE,
5322 					((bflags & XFS_BMAPI_NODISCARD) ||
5323 					del->br_state == XFS_EXT_UNWRITTEN));
5324 			if (error)
5325 				return error;
5326 		}
5327 	}
5328 
5329 	/*
5330 	 * Adjust inode # blocks in the file.
5331 	 */
5332 	if (nblks)
5333 		ip->i_nblocks -= nblks;
5334 	/*
5335 	 * Adjust quota data.
5336 	 */
5337 	if (qfield && !(bflags & XFS_BMAPI_REMAP))
5338 		xfs_trans_mod_dquot_byino(tp, ip, qfield, (long)-nblks);
5339 
5340 	return 0;
5341 }
5342 
5343 /*
5344  * Unmap (remove) blocks from a file.
5345  * If nexts is nonzero then the number of extents to remove is limited to
5346  * that value.  If not all extents in the block range can be removed then
5347  * *done is set.
5348  */
5349 static int
5350 __xfs_bunmapi(
5351 	struct xfs_trans	*tp,		/* transaction pointer */
5352 	struct xfs_inode	*ip,		/* incore inode */
5353 	xfs_fileoff_t		start,		/* first file offset deleted */
5354 	xfs_filblks_t		*rlen,		/* i/o: amount remaining */
5355 	uint32_t		flags,		/* misc flags */
5356 	xfs_extnum_t		nexts)		/* number of extents max */
5357 {
5358 	struct xfs_btree_cur	*cur;		/* bmap btree cursor */
5359 	struct xfs_bmbt_irec	del;		/* extent being deleted */
5360 	int			error;		/* error return value */
5361 	xfs_extnum_t		extno;		/* extent number in list */
5362 	struct xfs_bmbt_irec	got;		/* current extent record */
5363 	struct xfs_ifork	*ifp;		/* inode fork pointer */
5364 	int			isrt;		/* freeing in rt area */
5365 	int			logflags;	/* transaction logging flags */
5366 	xfs_extlen_t		mod;		/* rt extent offset */
5367 	struct xfs_mount	*mp = ip->i_mount;
5368 	int			tmp_logflags;	/* partial logging flags */
5369 	int			wasdel;		/* was a delayed alloc extent */
5370 	int			whichfork;	/* data or attribute fork */
5371 	xfs_filblks_t		len = *rlen;	/* length to unmap in file */
5372 	xfs_fileoff_t		end;
5373 	struct xfs_iext_cursor	icur;
5374 	bool			done = false;
5375 
5376 	trace_xfs_bunmap(ip, start, len, flags, _RET_IP_);
5377 
5378 	whichfork = xfs_bmapi_whichfork(flags);
5379 	ASSERT(whichfork != XFS_COW_FORK);
5380 	ifp = xfs_ifork_ptr(ip, whichfork);
5381 	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp))) {
5382 		xfs_bmap_mark_sick(ip, whichfork);
5383 		return -EFSCORRUPTED;
5384 	}
5385 	if (xfs_is_shutdown(mp))
5386 		return -EIO;
5387 
5388 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
5389 	ASSERT(len > 0);
5390 	ASSERT(nexts >= 0);
5391 
5392 	error = xfs_iread_extents(tp, ip, whichfork);
5393 	if (error)
5394 		return error;
5395 
5396 	if (xfs_iext_count(ifp) == 0) {
5397 		*rlen = 0;
5398 		return 0;
5399 	}
5400 	XFS_STATS_INC(mp, xs_blk_unmap);
5401 	isrt = xfs_ifork_is_realtime(ip, whichfork);
5402 	end = start + len;
5403 
5404 	if (!xfs_iext_lookup_extent_before(ip, ifp, &end, &icur, &got)) {
5405 		*rlen = 0;
5406 		return 0;
5407 	}
5408 	end--;
5409 
5410 	logflags = 0;
5411 	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
5412 		ASSERT(ifp->if_format == XFS_DINODE_FMT_BTREE);
5413 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5414 	} else
5415 		cur = NULL;
5416 
5417 	if (isrt) {
5418 		/*
5419 		 * Synchronize by locking the bitmap inode.
5420 		 */
5421 		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
5422 		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
5423 		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
5424 		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
5425 	}
5426 
5427 	extno = 0;
5428 	while (end != (xfs_fileoff_t)-1 && end >= start &&
5429 	       (nexts == 0 || extno < nexts)) {
5430 		/*
5431 		 * Is the found extent after a hole in which end lives?
5432 		 * Just back up to the previous extent, if so.
5433 		 */
5434 		if (got.br_startoff > end &&
5435 		    !xfs_iext_prev_extent(ifp, &icur, &got)) {
5436 			done = true;
5437 			break;
5438 		}
5439 		/*
5440 		 * Is the last block of this extent before the range
5441 		 * we're supposed to delete?  If so, we're done.
5442 		 */
5443 		end = XFS_FILEOFF_MIN(end,
5444 			got.br_startoff + got.br_blockcount - 1);
5445 		if (end < start)
5446 			break;
5447 		/*
5448 		 * Then deal with the (possibly delayed) allocated space
5449 		 * we found.
5450 		 */
5451 		del = got;
5452 		wasdel = isnullstartblock(del.br_startblock);
5453 
5454 		if (got.br_startoff < start) {
5455 			del.br_startoff = start;
5456 			del.br_blockcount -= start - got.br_startoff;
5457 			if (!wasdel)
5458 				del.br_startblock += start - got.br_startoff;
5459 		}
5460 		if (del.br_startoff + del.br_blockcount > end + 1)
5461 			del.br_blockcount = end + 1 - del.br_startoff;
5462 
5463 		if (!isrt || (flags & XFS_BMAPI_REMAP))
5464 			goto delete;
5465 
5466 		mod = xfs_rtb_to_rtxoff(mp,
5467 				del.br_startblock + del.br_blockcount);
5468 		if (mod) {
5469 			/*
5470 			 * Realtime extent not lined up at the end.
5471 			 * The extent could have been split into written
5472 			 * and unwritten pieces, or we could just be
5473 			 * unmapping part of it.  But we can't really
5474 			 * get rid of part of a realtime extent.
5475 			 */
5476 			if (del.br_state == XFS_EXT_UNWRITTEN) {
5477 				/*
5478 				 * This piece is unwritten, or we're not
5479 				 * using unwritten extents.  Skip over it.
5480 				 */
5481 				ASSERT((flags & XFS_BMAPI_REMAP) || end >= mod);
5482 				end -= mod > del.br_blockcount ?
5483 					del.br_blockcount : mod;
5484 				if (end < got.br_startoff &&
5485 				    !xfs_iext_prev_extent(ifp, &icur, &got)) {
5486 					done = true;
5487 					break;
5488 				}
5489 				continue;
5490 			}
5491 			/*
5492 			 * It's written, turn it unwritten.
5493 			 * This is better than zeroing it.
5494 			 */
5495 			ASSERT(del.br_state == XFS_EXT_NORM);
5496 			ASSERT(tp->t_blk_res > 0);
5497 			/*
5498 			 * If this spans a realtime extent boundary,
5499 			 * chop it back to the start of the one we end at.
5500 			 */
5501 			if (del.br_blockcount > mod) {
5502 				del.br_startoff += del.br_blockcount - mod;
5503 				del.br_startblock += del.br_blockcount - mod;
5504 				del.br_blockcount = mod;
5505 			}
5506 			del.br_state = XFS_EXT_UNWRITTEN;
5507 			error = xfs_bmap_add_extent_unwritten_real(tp, ip,
5508 					whichfork, &icur, &cur, &del,
5509 					&logflags);
5510 			if (error)
5511 				goto error0;
5512 			goto nodelete;
5513 		}
5514 
5515 		mod = xfs_rtb_to_rtxoff(mp, del.br_startblock);
5516 		if (mod) {
5517 			xfs_extlen_t off = mp->m_sb.sb_rextsize - mod;
5518 
5519 			/*
5520 			 * Realtime extent is lined up at the end but not
5521 			 * at the front.  We'll get rid of full extents if
5522 			 * we can.
5523 			 */
5524 			if (del.br_blockcount > off) {
5525 				del.br_blockcount -= off;
5526 				del.br_startoff += off;
5527 				del.br_startblock += off;
5528 			} else if (del.br_startoff == start &&
5529 				   (del.br_state == XFS_EXT_UNWRITTEN ||
5530 				    tp->t_blk_res == 0)) {
5531 				/*
5532 				 * Can't make it unwritten.  There isn't
5533 				 * a full extent here so just skip it.
5534 				 */
5535 				ASSERT(end >= del.br_blockcount);
5536 				end -= del.br_blockcount;
5537 				if (got.br_startoff > end &&
5538 				    !xfs_iext_prev_extent(ifp, &icur, &got)) {
5539 					done = true;
5540 					break;
5541 				}
5542 				continue;
5543 			} else if (del.br_state == XFS_EXT_UNWRITTEN) {
5544 				struct xfs_bmbt_irec	prev;
5545 				xfs_fileoff_t		unwrite_start;
5546 
5547 				/*
5548 				 * This one is already unwritten.
5549 				 * It must have a written left neighbor.
5550 				 * Unwrite the killed part of that one and
5551 				 * try again.
5552 				 */
5553 				if (!xfs_iext_prev_extent(ifp, &icur, &prev))
5554 					ASSERT(0);
5555 				ASSERT(prev.br_state == XFS_EXT_NORM);
5556 				ASSERT(!isnullstartblock(prev.br_startblock));
5557 				ASSERT(del.br_startblock ==
5558 				       prev.br_startblock + prev.br_blockcount);
5559 				unwrite_start = max3(start,
5560 						     del.br_startoff - mod,
5561 						     prev.br_startoff);
5562 				mod = unwrite_start - prev.br_startoff;
5563 				prev.br_startoff = unwrite_start;
5564 				prev.br_startblock += mod;
5565 				prev.br_blockcount -= mod;
5566 				prev.br_state = XFS_EXT_UNWRITTEN;
5567 				error = xfs_bmap_add_extent_unwritten_real(tp,
5568 						ip, whichfork, &icur, &cur,
5569 						&prev, &logflags);
5570 				if (error)
5571 					goto error0;
5572 				goto nodelete;
5573 			} else {
5574 				ASSERT(del.br_state == XFS_EXT_NORM);
5575 				del.br_state = XFS_EXT_UNWRITTEN;
5576 				error = xfs_bmap_add_extent_unwritten_real(tp,
5577 						ip, whichfork, &icur, &cur,
5578 						&del, &logflags);
5579 				if (error)
5580 					goto error0;
5581 				goto nodelete;
5582 			}
5583 		}
5584 
5585 delete:
5586 		if (wasdel) {
5587 			error = xfs_bmap_del_extent_delay(ip, whichfork, &icur,
5588 					&got, &del);
5589 		} else {
5590 			error = xfs_bmap_del_extent_real(ip, tp, &icur, cur,
5591 					&del, &tmp_logflags, whichfork,
5592 					flags);
5593 			logflags |= tmp_logflags;
5594 		}
5595 
5596 		if (error)
5597 			goto error0;
5598 
5599 		end = del.br_startoff - 1;
5600 nodelete:
5601 		/*
5602 		 * If not done go on to the next (previous) record.
5603 		 */
5604 		if (end != (xfs_fileoff_t)-1 && end >= start) {
5605 			if (!xfs_iext_get_extent(ifp, &icur, &got) ||
5606 			    (got.br_startoff > end &&
5607 			     !xfs_iext_prev_extent(ifp, &icur, &got))) {
5608 				done = true;
5609 				break;
5610 			}
5611 			extno++;
5612 		}
5613 	}
5614 	if (done || end == (xfs_fileoff_t)-1 || end < start)
5615 		*rlen = 0;
5616 	else
5617 		*rlen = end - start + 1;
5618 
5619 	/*
5620 	 * Convert to a btree if necessary.
5621 	 */
5622 	if (xfs_bmap_needs_btree(ip, whichfork)) {
5623 		ASSERT(cur == NULL);
5624 		error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
5625 				&tmp_logflags, whichfork);
5626 		logflags |= tmp_logflags;
5627 	} else {
5628 		error = xfs_bmap_btree_to_extents(tp, ip, cur, &logflags,
5629 			whichfork);
5630 	}
5631 
5632 error0:
5633 	/*
5634 	 * Log everything.  Do this after conversion, there's no point in
5635 	 * logging the extent records if we've converted to btree format.
5636 	 */
5637 	if ((logflags & xfs_ilog_fext(whichfork)) &&
5638 	    ifp->if_format != XFS_DINODE_FMT_EXTENTS)
5639 		logflags &= ~xfs_ilog_fext(whichfork);
5640 	else if ((logflags & xfs_ilog_fbroot(whichfork)) &&
5641 		 ifp->if_format != XFS_DINODE_FMT_BTREE)
5642 		logflags &= ~xfs_ilog_fbroot(whichfork);
5643 	/*
5644 	 * Log inode even in the error case, if the transaction
5645 	 * is dirty we'll need to shut down the filesystem.
5646 	 */
5647 	if (logflags)
5648 		xfs_trans_log_inode(tp, ip, logflags);
5649 	if (cur) {
5650 		if (!error)
5651 			cur->bc_bmap.allocated = 0;
5652 		xfs_btree_del_cursor(cur, error);
5653 	}
5654 	return error;
5655 }
5656 
5657 /* Unmap a range of a file. */
5658 int
5659 xfs_bunmapi(
5660 	xfs_trans_t		*tp,
5661 	struct xfs_inode	*ip,
5662 	xfs_fileoff_t		bno,
5663 	xfs_filblks_t		len,
5664 	uint32_t		flags,
5665 	xfs_extnum_t		nexts,
5666 	int			*done)
5667 {
5668 	int			error;
5669 
5670 	error = __xfs_bunmapi(tp, ip, bno, &len, flags, nexts);
5671 	*done = (len == 0);
5672 	return error;
5673 }
5674 
5675 /*
5676  * Determine whether an extent shift can be accomplished by a merge with the
5677  * extent that precedes the target hole of the shift.
5678  */
5679 STATIC bool
5680 xfs_bmse_can_merge(
5681 	struct xfs_bmbt_irec	*left,	/* preceding extent */
5682 	struct xfs_bmbt_irec	*got,	/* current extent to shift */
5683 	xfs_fileoff_t		shift)	/* shift fsb */
5684 {
5685 	xfs_fileoff_t		startoff;
5686 
5687 	startoff = got->br_startoff - shift;
5688 
5689 	/*
5690 	 * The extent, once shifted, must be adjacent in-file and on-disk with
5691 	 * the preceding extent.
5692 	 */
5693 	if ((left->br_startoff + left->br_blockcount != startoff) ||
5694 	    (left->br_startblock + left->br_blockcount != got->br_startblock) ||
5695 	    (left->br_state != got->br_state) ||
5696 	    (left->br_blockcount + got->br_blockcount > XFS_MAX_BMBT_EXTLEN))
5697 		return false;
5698 
5699 	return true;
5700 }
5701 
5702 /*
5703  * A bmap extent shift adjusts the file offset of an extent to fill a preceding
5704  * hole in the file. If an extent shift would result in the extent being fully
5705  * adjacent to the extent that currently precedes the hole, we can merge with
5706  * the preceding extent rather than do the shift.
5707  *
5708  * This function assumes the caller has verified a shift-by-merge is possible
5709  * with the provided extents via xfs_bmse_can_merge().
5710  */
5711 STATIC int
5712 xfs_bmse_merge(
5713 	struct xfs_trans		*tp,
5714 	struct xfs_inode		*ip,
5715 	int				whichfork,
5716 	xfs_fileoff_t			shift,		/* shift fsb */
5717 	struct xfs_iext_cursor		*icur,
5718 	struct xfs_bmbt_irec		*got,		/* extent to shift */
5719 	struct xfs_bmbt_irec		*left,		/* preceding extent */
5720 	struct xfs_btree_cur		*cur,
5721 	int				*logflags)	/* output */
5722 {
5723 	struct xfs_ifork		*ifp = xfs_ifork_ptr(ip, whichfork);
5724 	struct xfs_bmbt_irec		new;
5725 	xfs_filblks_t			blockcount;
5726 	int				error, i;
5727 	struct xfs_mount		*mp = ip->i_mount;
5728 
5729 	blockcount = left->br_blockcount + got->br_blockcount;
5730 
5731 	xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
5732 	ASSERT(xfs_bmse_can_merge(left, got, shift));
5733 
5734 	new = *left;
5735 	new.br_blockcount = blockcount;
5736 
5737 	/*
5738 	 * Update the on-disk extent count, the btree if necessary and log the
5739 	 * inode.
5740 	 */
5741 	ifp->if_nextents--;
5742 	*logflags |= XFS_ILOG_CORE;
5743 	if (!cur) {
5744 		*logflags |= XFS_ILOG_DEXT;
5745 		goto done;
5746 	}
5747 
5748 	/* lookup and remove the extent to merge */
5749 	error = xfs_bmbt_lookup_eq(cur, got, &i);
5750 	if (error)
5751 		return error;
5752 	if (XFS_IS_CORRUPT(mp, i != 1)) {
5753 		xfs_btree_mark_sick(cur);
5754 		return -EFSCORRUPTED;
5755 	}
5756 
5757 	error = xfs_btree_delete(cur, &i);
5758 	if (error)
5759 		return error;
5760 	if (XFS_IS_CORRUPT(mp, i != 1)) {
5761 		xfs_btree_mark_sick(cur);
5762 		return -EFSCORRUPTED;
5763 	}
5764 
5765 	/* lookup and update size of the previous extent */
5766 	error = xfs_bmbt_lookup_eq(cur, left, &i);
5767 	if (error)
5768 		return error;
5769 	if (XFS_IS_CORRUPT(mp, i != 1)) {
5770 		xfs_btree_mark_sick(cur);
5771 		return -EFSCORRUPTED;
5772 	}
5773 
5774 	error = xfs_bmbt_update(cur, &new);
5775 	if (error)
5776 		return error;
5777 
5778 	/* change to extent format if required after extent removal */
5779 	error = xfs_bmap_btree_to_extents(tp, ip, cur, logflags, whichfork);
5780 	if (error)
5781 		return error;
5782 
5783 done:
5784 	xfs_iext_remove(ip, icur, 0);
5785 	xfs_iext_prev(ifp, icur);
5786 	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), icur,
5787 			&new);
5788 
5789 	/* update reverse mapping. rmap functions merge the rmaps for us */
5790 	xfs_rmap_unmap_extent(tp, ip, whichfork, got);
5791 	memcpy(&new, got, sizeof(new));
5792 	new.br_startoff = left->br_startoff + left->br_blockcount;
5793 	xfs_rmap_map_extent(tp, ip, whichfork, &new);
5794 	return 0;
5795 }
5796 
5797 static int
5798 xfs_bmap_shift_update_extent(
5799 	struct xfs_trans	*tp,
5800 	struct xfs_inode	*ip,
5801 	int			whichfork,
5802 	struct xfs_iext_cursor	*icur,
5803 	struct xfs_bmbt_irec	*got,
5804 	struct xfs_btree_cur	*cur,
5805 	int			*logflags,
5806 	xfs_fileoff_t		startoff)
5807 {
5808 	struct xfs_mount	*mp = ip->i_mount;
5809 	struct xfs_bmbt_irec	prev = *got;
5810 	int			error, i;
5811 
5812 	*logflags |= XFS_ILOG_CORE;
5813 
5814 	got->br_startoff = startoff;
5815 
5816 	if (cur) {
5817 		error = xfs_bmbt_lookup_eq(cur, &prev, &i);
5818 		if (error)
5819 			return error;
5820 		if (XFS_IS_CORRUPT(mp, i != 1)) {
5821 			xfs_btree_mark_sick(cur);
5822 			return -EFSCORRUPTED;
5823 		}
5824 
5825 		error = xfs_bmbt_update(cur, got);
5826 		if (error)
5827 			return error;
5828 	} else {
5829 		*logflags |= XFS_ILOG_DEXT;
5830 	}
5831 
5832 	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), icur,
5833 			got);
5834 
5835 	/* update reverse mapping */
5836 	xfs_rmap_unmap_extent(tp, ip, whichfork, &prev);
5837 	xfs_rmap_map_extent(tp, ip, whichfork, got);
5838 	return 0;
5839 }
5840 
5841 int
5842 xfs_bmap_collapse_extents(
5843 	struct xfs_trans	*tp,
5844 	struct xfs_inode	*ip,
5845 	xfs_fileoff_t		*next_fsb,
5846 	xfs_fileoff_t		offset_shift_fsb,
5847 	bool			*done)
5848 {
5849 	int			whichfork = XFS_DATA_FORK;
5850 	struct xfs_mount	*mp = ip->i_mount;
5851 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
5852 	struct xfs_btree_cur	*cur = NULL;
5853 	struct xfs_bmbt_irec	got, prev;
5854 	struct xfs_iext_cursor	icur;
5855 	xfs_fileoff_t		new_startoff;
5856 	int			error = 0;
5857 	int			logflags = 0;
5858 
5859 	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
5860 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
5861 		xfs_bmap_mark_sick(ip, whichfork);
5862 		return -EFSCORRUPTED;
5863 	}
5864 
5865 	if (xfs_is_shutdown(mp))
5866 		return -EIO;
5867 
5868 	xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
5869 
5870 	error = xfs_iread_extents(tp, ip, whichfork);
5871 	if (error)
5872 		return error;
5873 
5874 	if (ifp->if_format == XFS_DINODE_FMT_BTREE)
5875 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5876 
5877 	if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &icur, &got)) {
5878 		*done = true;
5879 		goto del_cursor;
5880 	}
5881 	if (XFS_IS_CORRUPT(mp, isnullstartblock(got.br_startblock))) {
5882 		xfs_bmap_mark_sick(ip, whichfork);
5883 		error = -EFSCORRUPTED;
5884 		goto del_cursor;
5885 	}
5886 
5887 	new_startoff = got.br_startoff - offset_shift_fsb;
5888 	if (xfs_iext_peek_prev_extent(ifp, &icur, &prev)) {
5889 		if (new_startoff < prev.br_startoff + prev.br_blockcount) {
5890 			error = -EINVAL;
5891 			goto del_cursor;
5892 		}
5893 
5894 		if (xfs_bmse_can_merge(&prev, &got, offset_shift_fsb)) {
5895 			error = xfs_bmse_merge(tp, ip, whichfork,
5896 					offset_shift_fsb, &icur, &got, &prev,
5897 					cur, &logflags);
5898 			if (error)
5899 				goto del_cursor;
5900 			goto done;
5901 		}
5902 	} else {
5903 		if (got.br_startoff < offset_shift_fsb) {
5904 			error = -EINVAL;
5905 			goto del_cursor;
5906 		}
5907 	}
5908 
5909 	error = xfs_bmap_shift_update_extent(tp, ip, whichfork, &icur, &got,
5910 			cur, &logflags, new_startoff);
5911 	if (error)
5912 		goto del_cursor;
5913 
5914 done:
5915 	if (!xfs_iext_next_extent(ifp, &icur, &got)) {
5916 		*done = true;
5917 		goto del_cursor;
5918 	}
5919 
5920 	*next_fsb = got.br_startoff;
5921 del_cursor:
5922 	if (cur)
5923 		xfs_btree_del_cursor(cur, error);
5924 	if (logflags)
5925 		xfs_trans_log_inode(tp, ip, logflags);
5926 	return error;
5927 }
5928 
5929 /* Make sure we won't be right-shifting an extent past the maximum bound. */
5930 int
5931 xfs_bmap_can_insert_extents(
5932 	struct xfs_inode	*ip,
5933 	xfs_fileoff_t		off,
5934 	xfs_fileoff_t		shift)
5935 {
5936 	struct xfs_bmbt_irec	got;
5937 	int			is_empty;
5938 	int			error = 0;
5939 
5940 	xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL);
5941 
5942 	if (xfs_is_shutdown(ip->i_mount))
5943 		return -EIO;
5944 
5945 	xfs_ilock(ip, XFS_ILOCK_EXCL);
5946 	error = xfs_bmap_last_extent(NULL, ip, XFS_DATA_FORK, &got, &is_empty);
5947 	if (!error && !is_empty && got.br_startoff >= off &&
5948 	    ((got.br_startoff + shift) & BMBT_STARTOFF_MASK) < got.br_startoff)
5949 		error = -EINVAL;
5950 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
5951 
5952 	return error;
5953 }
5954 
5955 int
5956 xfs_bmap_insert_extents(
5957 	struct xfs_trans	*tp,
5958 	struct xfs_inode	*ip,
5959 	xfs_fileoff_t		*next_fsb,
5960 	xfs_fileoff_t		offset_shift_fsb,
5961 	bool			*done,
5962 	xfs_fileoff_t		stop_fsb)
5963 {
5964 	int			whichfork = XFS_DATA_FORK;
5965 	struct xfs_mount	*mp = ip->i_mount;
5966 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
5967 	struct xfs_btree_cur	*cur = NULL;
5968 	struct xfs_bmbt_irec	got, next;
5969 	struct xfs_iext_cursor	icur;
5970 	xfs_fileoff_t		new_startoff;
5971 	int			error = 0;
5972 	int			logflags = 0;
5973 
5974 	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
5975 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
5976 		xfs_bmap_mark_sick(ip, whichfork);
5977 		return -EFSCORRUPTED;
5978 	}
5979 
5980 	if (xfs_is_shutdown(mp))
5981 		return -EIO;
5982 
5983 	xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
5984 
5985 	error = xfs_iread_extents(tp, ip, whichfork);
5986 	if (error)
5987 		return error;
5988 
5989 	if (ifp->if_format == XFS_DINODE_FMT_BTREE)
5990 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5991 
5992 	if (*next_fsb == NULLFSBLOCK) {
5993 		xfs_iext_last(ifp, &icur);
5994 		if (!xfs_iext_get_extent(ifp, &icur, &got) ||
5995 		    stop_fsb > got.br_startoff) {
5996 			*done = true;
5997 			goto del_cursor;
5998 		}
5999 	} else {
6000 		if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &icur, &got)) {
6001 			*done = true;
6002 			goto del_cursor;
6003 		}
6004 	}
6005 	if (XFS_IS_CORRUPT(mp, isnullstartblock(got.br_startblock))) {
6006 		xfs_bmap_mark_sick(ip, whichfork);
6007 		error = -EFSCORRUPTED;
6008 		goto del_cursor;
6009 	}
6010 
6011 	if (XFS_IS_CORRUPT(mp, stop_fsb > got.br_startoff)) {
6012 		xfs_bmap_mark_sick(ip, whichfork);
6013 		error = -EFSCORRUPTED;
6014 		goto del_cursor;
6015 	}
6016 
6017 	new_startoff = got.br_startoff + offset_shift_fsb;
6018 	if (xfs_iext_peek_next_extent(ifp, &icur, &next)) {
6019 		if (new_startoff + got.br_blockcount > next.br_startoff) {
6020 			error = -EINVAL;
6021 			goto del_cursor;
6022 		}
6023 
6024 		/*
6025 		 * Unlike a left shift (which involves a hole punch), a right
6026 		 * shift does not modify extent neighbors in any way.  We should
6027 		 * never find mergeable extents in this scenario.  Check anyways
6028 		 * and warn if we encounter two extents that could be one.
6029 		 */
6030 		if (xfs_bmse_can_merge(&got, &next, offset_shift_fsb))
6031 			WARN_ON_ONCE(1);
6032 	}
6033 
6034 	error = xfs_bmap_shift_update_extent(tp, ip, whichfork, &icur, &got,
6035 			cur, &logflags, new_startoff);
6036 	if (error)
6037 		goto del_cursor;
6038 
6039 	if (!xfs_iext_prev_extent(ifp, &icur, &got) ||
6040 	    stop_fsb >= got.br_startoff + got.br_blockcount) {
6041 		*done = true;
6042 		goto del_cursor;
6043 	}
6044 
6045 	*next_fsb = got.br_startoff;
6046 del_cursor:
6047 	if (cur)
6048 		xfs_btree_del_cursor(cur, error);
6049 	if (logflags)
6050 		xfs_trans_log_inode(tp, ip, logflags);
6051 	return error;
6052 }
6053 
6054 /*
6055  * Splits an extent into two extents at split_fsb block such that it is the
6056  * first block of the current_ext. @ext is a target extent to be split.
6057  * @split_fsb is a block where the extents is split.  If split_fsb lies in a
6058  * hole or the first block of extents, just return 0.
6059  */
6060 int
6061 xfs_bmap_split_extent(
6062 	struct xfs_trans	*tp,
6063 	struct xfs_inode	*ip,
6064 	xfs_fileoff_t		split_fsb)
6065 {
6066 	int				whichfork = XFS_DATA_FORK;
6067 	struct xfs_ifork		*ifp = xfs_ifork_ptr(ip, whichfork);
6068 	struct xfs_btree_cur		*cur = NULL;
6069 	struct xfs_bmbt_irec		got;
6070 	struct xfs_bmbt_irec		new; /* split extent */
6071 	struct xfs_mount		*mp = ip->i_mount;
6072 	xfs_fsblock_t			gotblkcnt; /* new block count for got */
6073 	struct xfs_iext_cursor		icur;
6074 	int				error = 0;
6075 	int				logflags = 0;
6076 	int				i = 0;
6077 
6078 	if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
6079 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
6080 		xfs_bmap_mark_sick(ip, whichfork);
6081 		return -EFSCORRUPTED;
6082 	}
6083 
6084 	if (xfs_is_shutdown(mp))
6085 		return -EIO;
6086 
6087 	/* Read in all the extents */
6088 	error = xfs_iread_extents(tp, ip, whichfork);
6089 	if (error)
6090 		return error;
6091 
6092 	/*
6093 	 * If there are not extents, or split_fsb lies in a hole we are done.
6094 	 */
6095 	if (!xfs_iext_lookup_extent(ip, ifp, split_fsb, &icur, &got) ||
6096 	    got.br_startoff >= split_fsb)
6097 		return 0;
6098 
6099 	gotblkcnt = split_fsb - got.br_startoff;
6100 	new.br_startoff = split_fsb;
6101 	new.br_startblock = got.br_startblock + gotblkcnt;
6102 	new.br_blockcount = got.br_blockcount - gotblkcnt;
6103 	new.br_state = got.br_state;
6104 
6105 	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
6106 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
6107 		error = xfs_bmbt_lookup_eq(cur, &got, &i);
6108 		if (error)
6109 			goto del_cursor;
6110 		if (XFS_IS_CORRUPT(mp, i != 1)) {
6111 			xfs_btree_mark_sick(cur);
6112 			error = -EFSCORRUPTED;
6113 			goto del_cursor;
6114 		}
6115 	}
6116 
6117 	got.br_blockcount = gotblkcnt;
6118 	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), &icur,
6119 			&got);
6120 
6121 	logflags = XFS_ILOG_CORE;
6122 	if (cur) {
6123 		error = xfs_bmbt_update(cur, &got);
6124 		if (error)
6125 			goto del_cursor;
6126 	} else
6127 		logflags |= XFS_ILOG_DEXT;
6128 
6129 	/* Add new extent */
6130 	xfs_iext_next(ifp, &icur);
6131 	xfs_iext_insert(ip, &icur, &new, 0);
6132 	ifp->if_nextents++;
6133 
6134 	if (cur) {
6135 		error = xfs_bmbt_lookup_eq(cur, &new, &i);
6136 		if (error)
6137 			goto del_cursor;
6138 		if (XFS_IS_CORRUPT(mp, i != 0)) {
6139 			xfs_btree_mark_sick(cur);
6140 			error = -EFSCORRUPTED;
6141 			goto del_cursor;
6142 		}
6143 		error = xfs_btree_insert(cur, &i);
6144 		if (error)
6145 			goto del_cursor;
6146 		if (XFS_IS_CORRUPT(mp, i != 1)) {
6147 			xfs_btree_mark_sick(cur);
6148 			error = -EFSCORRUPTED;
6149 			goto del_cursor;
6150 		}
6151 	}
6152 
6153 	/*
6154 	 * Convert to a btree if necessary.
6155 	 */
6156 	if (xfs_bmap_needs_btree(ip, whichfork)) {
6157 		int tmp_logflags; /* partial log flag return val */
6158 
6159 		ASSERT(cur == NULL);
6160 		error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
6161 				&tmp_logflags, whichfork);
6162 		logflags |= tmp_logflags;
6163 	}
6164 
6165 del_cursor:
6166 	if (cur) {
6167 		cur->bc_bmap.allocated = 0;
6168 		xfs_btree_del_cursor(cur, error);
6169 	}
6170 
6171 	if (logflags)
6172 		xfs_trans_log_inode(tp, ip, logflags);
6173 	return error;
6174 }
6175 
6176 /* Record a bmap intent. */
6177 static inline void
6178 __xfs_bmap_add(
6179 	struct xfs_trans		*tp,
6180 	enum xfs_bmap_intent_type	type,
6181 	struct xfs_inode		*ip,
6182 	int				whichfork,
6183 	struct xfs_bmbt_irec		*bmap)
6184 {
6185 	struct xfs_bmap_intent		*bi;
6186 
6187 	if ((whichfork != XFS_DATA_FORK && whichfork != XFS_ATTR_FORK) ||
6188 	    bmap->br_startblock == HOLESTARTBLOCK ||
6189 	    bmap->br_startblock == DELAYSTARTBLOCK)
6190 		return;
6191 
6192 	bi = kmem_cache_alloc(xfs_bmap_intent_cache, GFP_KERNEL | __GFP_NOFAIL);
6193 	INIT_LIST_HEAD(&bi->bi_list);
6194 	bi->bi_type = type;
6195 	bi->bi_owner = ip;
6196 	bi->bi_whichfork = whichfork;
6197 	bi->bi_bmap = *bmap;
6198 
6199 	xfs_bmap_defer_add(tp, bi);
6200 }
6201 
6202 /* Map an extent into a file. */
6203 void
6204 xfs_bmap_map_extent(
6205 	struct xfs_trans	*tp,
6206 	struct xfs_inode	*ip,
6207 	int			whichfork,
6208 	struct xfs_bmbt_irec	*PREV)
6209 {
6210 	__xfs_bmap_add(tp, XFS_BMAP_MAP, ip, whichfork, PREV);
6211 }
6212 
6213 /* Unmap an extent out of a file. */
6214 void
6215 xfs_bmap_unmap_extent(
6216 	struct xfs_trans	*tp,
6217 	struct xfs_inode	*ip,
6218 	int			whichfork,
6219 	struct xfs_bmbt_irec	*PREV)
6220 {
6221 	__xfs_bmap_add(tp, XFS_BMAP_UNMAP, ip, whichfork, PREV);
6222 }
6223 
6224 /*
6225  * Process one of the deferred bmap operations.  We pass back the
6226  * btree cursor to maintain our lock on the bmapbt between calls.
6227  */
6228 int
6229 xfs_bmap_finish_one(
6230 	struct xfs_trans		*tp,
6231 	struct xfs_bmap_intent		*bi)
6232 {
6233 	struct xfs_bmbt_irec		*bmap = &bi->bi_bmap;
6234 	int				error = 0;
6235 	int				flags = 0;
6236 
6237 	if (bi->bi_whichfork == XFS_ATTR_FORK)
6238 		flags |= XFS_BMAPI_ATTRFORK;
6239 
6240 	ASSERT(tp->t_highest_agno == NULLAGNUMBER);
6241 
6242 	trace_xfs_bmap_deferred(bi);
6243 
6244 	if (XFS_TEST_ERROR(false, tp->t_mountp, XFS_ERRTAG_BMAP_FINISH_ONE))
6245 		return -EIO;
6246 
6247 	switch (bi->bi_type) {
6248 	case XFS_BMAP_MAP:
6249 		if (bi->bi_bmap.br_state == XFS_EXT_UNWRITTEN)
6250 			flags |= XFS_BMAPI_PREALLOC;
6251 		error = xfs_bmapi_remap(tp, bi->bi_owner, bmap->br_startoff,
6252 				bmap->br_blockcount, bmap->br_startblock,
6253 				flags);
6254 		bmap->br_blockcount = 0;
6255 		break;
6256 	case XFS_BMAP_UNMAP:
6257 		error = __xfs_bunmapi(tp, bi->bi_owner, bmap->br_startoff,
6258 				&bmap->br_blockcount, flags | XFS_BMAPI_REMAP,
6259 				1);
6260 		break;
6261 	default:
6262 		ASSERT(0);
6263 		xfs_bmap_mark_sick(bi->bi_owner, bi->bi_whichfork);
6264 		error = -EFSCORRUPTED;
6265 	}
6266 
6267 	return error;
6268 }
6269 
6270 /* Check that an extent does not have invalid flags or bad ranges. */
6271 xfs_failaddr_t
6272 xfs_bmap_validate_extent_raw(
6273 	struct xfs_mount	*mp,
6274 	bool			rtfile,
6275 	int			whichfork,
6276 	struct xfs_bmbt_irec	*irec)
6277 {
6278 	if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
6279 		return __this_address;
6280 
6281 	if (rtfile && whichfork == XFS_DATA_FORK) {
6282 		if (!xfs_verify_rtbext(mp, irec->br_startblock,
6283 					   irec->br_blockcount))
6284 			return __this_address;
6285 	} else {
6286 		if (!xfs_verify_fsbext(mp, irec->br_startblock,
6287 					   irec->br_blockcount))
6288 			return __this_address;
6289 	}
6290 	if (irec->br_state != XFS_EXT_NORM && whichfork != XFS_DATA_FORK)
6291 		return __this_address;
6292 	return NULL;
6293 }
6294 
6295 int __init
6296 xfs_bmap_intent_init_cache(void)
6297 {
6298 	xfs_bmap_intent_cache = kmem_cache_create("xfs_bmap_intent",
6299 			sizeof(struct xfs_bmap_intent),
6300 			0, 0, NULL);
6301 
6302 	return xfs_bmap_intent_cache != NULL ? 0 : -ENOMEM;
6303 }
6304 
6305 void
6306 xfs_bmap_intent_destroy_cache(void)
6307 {
6308 	kmem_cache_destroy(xfs_bmap_intent_cache);
6309 	xfs_bmap_intent_cache = NULL;
6310 }
6311 
6312 /* Check that an inode's extent does not have invalid flags or bad ranges. */
6313 xfs_failaddr_t
6314 xfs_bmap_validate_extent(
6315 	struct xfs_inode	*ip,
6316 	int			whichfork,
6317 	struct xfs_bmbt_irec	*irec)
6318 {
6319 	return xfs_bmap_validate_extent_raw(ip->i_mount,
6320 			XFS_IS_REALTIME_INODE(ip), whichfork, irec);
6321 }
6322 
6323 /*
6324  * Used in xfs_itruncate_extents().  This is the maximum number of extents
6325  * freed from a file in a single transaction.
6326  */
6327 #define	XFS_ITRUNC_MAX_EXTENTS	2
6328 
6329 /*
6330  * Unmap every extent in part of an inode's fork.  We don't do any higher level
6331  * invalidation work at all.
6332  */
6333 int
6334 xfs_bunmapi_range(
6335 	struct xfs_trans	**tpp,
6336 	struct xfs_inode	*ip,
6337 	uint32_t		flags,
6338 	xfs_fileoff_t		startoff,
6339 	xfs_fileoff_t		endoff)
6340 {
6341 	xfs_filblks_t		unmap_len = endoff - startoff + 1;
6342 	int			error = 0;
6343 
6344 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
6345 
6346 	while (unmap_len > 0) {
6347 		ASSERT((*tpp)->t_highest_agno == NULLAGNUMBER);
6348 		error = __xfs_bunmapi(*tpp, ip, startoff, &unmap_len, flags,
6349 				XFS_ITRUNC_MAX_EXTENTS);
6350 		if (error)
6351 			goto out;
6352 
6353 		/* free the just unmapped extents */
6354 		error = xfs_defer_finish(tpp);
6355 		if (error)
6356 			goto out;
6357 	}
6358 out:
6359 	return error;
6360 }
6361 
6362 struct xfs_bmap_query_range {
6363 	xfs_bmap_query_range_fn	fn;
6364 	void			*priv;
6365 };
6366 
6367 /* Format btree record and pass to our callback. */
6368 STATIC int
6369 xfs_bmap_query_range_helper(
6370 	struct xfs_btree_cur		*cur,
6371 	const union xfs_btree_rec	*rec,
6372 	void				*priv)
6373 {
6374 	struct xfs_bmap_query_range	*query = priv;
6375 	struct xfs_bmbt_irec		irec;
6376 	xfs_failaddr_t			fa;
6377 
6378 	xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
6379 	fa = xfs_bmap_validate_extent(cur->bc_ino.ip, cur->bc_ino.whichfork,
6380 			&irec);
6381 	if (fa) {
6382 		xfs_btree_mark_sick(cur);
6383 		return xfs_bmap_complain_bad_rec(cur->bc_ino.ip,
6384 				cur->bc_ino.whichfork, fa, &irec);
6385 	}
6386 
6387 	return query->fn(cur, &irec, query->priv);
6388 }
6389 
6390 /* Find all bmaps. */
6391 int
6392 xfs_bmap_query_all(
6393 	struct xfs_btree_cur		*cur,
6394 	xfs_bmap_query_range_fn		fn,
6395 	void				*priv)
6396 {
6397 	struct xfs_bmap_query_range	query = {
6398 		.priv			= priv,
6399 		.fn			= fn,
6400 	};
6401 
6402 	return xfs_btree_query_all(cur, xfs_bmap_query_range_helper, &query);
6403 }
6404