xref: /linux/fs/xfs/xfs_iomap.c (revision 2624f124b3b5d550ab2fbef7ee3bc0e1fed09722)
1 /*
2  * Copyright (c) 2000-2004 Silicon Graphics, Inc.  All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it would be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11  *
12  * Further, this software is distributed without any warranty that it is
13  * free of the rightful claim of any third person regarding infringement
14  * or the like.	 Any license provided herein, whether implied or
15  * otherwise, applies only to this software file.  Patent licenses, if
16  * any, provided herein do not apply to combinations of this program with
17  * other software, or any other product whatsoever.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write the Free Software Foundation, Inc., 59
21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22  *
23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24  * Mountain View, CA  94043, or:
25  *
26  * http://www.sgi.com
27  *
28  * For further information regarding this notice, see:
29  *
30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31  */
32 
33 #include "xfs.h"
34 
35 #include "xfs_fs.h"
36 #include "xfs_inum.h"
37 #include "xfs_log.h"
38 #include "xfs_trans.h"
39 #include "xfs_sb.h"
40 #include "xfs_ag.h"
41 #include "xfs_dir.h"
42 #include "xfs_dir2.h"
43 #include "xfs_alloc.h"
44 #include "xfs_dmapi.h"
45 #include "xfs_quota.h"
46 #include "xfs_mount.h"
47 #include "xfs_alloc_btree.h"
48 #include "xfs_bmap_btree.h"
49 #include "xfs_ialloc_btree.h"
50 #include "xfs_btree.h"
51 #include "xfs_ialloc.h"
52 #include "xfs_attr_sf.h"
53 #include "xfs_dir_sf.h"
54 #include "xfs_dir2_sf.h"
55 #include "xfs_dinode.h"
56 #include "xfs_inode.h"
57 #include "xfs_bmap.h"
58 #include "xfs_bit.h"
59 #include "xfs_rtalloc.h"
60 #include "xfs_error.h"
61 #include "xfs_itable.h"
62 #include "xfs_rw.h"
63 #include "xfs_acl.h"
64 #include "xfs_cap.h"
65 #include "xfs_mac.h"
66 #include "xfs_attr.h"
67 #include "xfs_buf_item.h"
68 #include "xfs_trans_space.h"
69 #include "xfs_utils.h"
70 #include "xfs_iomap.h"
71 
72 #if defined(XFS_RW_TRACE)
73 void
74 xfs_iomap_enter_trace(
75 	int		tag,
76 	xfs_iocore_t	*io,
77 	xfs_off_t	offset,
78 	ssize_t		count)
79 {
80 	xfs_inode_t	*ip = XFS_IO_INODE(io);
81 
82 	if (!ip->i_rwtrace)
83 		return;
84 
85 	ktrace_enter(ip->i_rwtrace,
86 		(void *)((unsigned long)tag),
87 		(void *)ip,
88 		(void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
89 		(void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
90 		(void *)((unsigned long)((offset >> 32) & 0xffffffff)),
91 		(void *)((unsigned long)(offset & 0xffffffff)),
92 		(void *)((unsigned long)count),
93 		(void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
94 		(void *)((unsigned long)(io->io_new_size & 0xffffffff)),
95 		(void *)NULL,
96 		(void *)NULL,
97 		(void *)NULL,
98 		(void *)NULL,
99 		(void *)NULL,
100 		(void *)NULL,
101 		(void *)NULL);
102 }
103 
104 void
105 xfs_iomap_map_trace(
106 	int		tag,
107 	xfs_iocore_t	*io,
108 	xfs_off_t	offset,
109 	ssize_t		count,
110 	xfs_iomap_t	*iomapp,
111 	xfs_bmbt_irec_t	*imapp,
112 	int		flags)
113 {
114 	xfs_inode_t	*ip = XFS_IO_INODE(io);
115 
116 	if (!ip->i_rwtrace)
117 		return;
118 
119 	ktrace_enter(ip->i_rwtrace,
120 		(void *)((unsigned long)tag),
121 		(void *)ip,
122 		(void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
123 		(void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
124 		(void *)((unsigned long)((offset >> 32) & 0xffffffff)),
125 		(void *)((unsigned long)(offset & 0xffffffff)),
126 		(void *)((unsigned long)count),
127 		(void *)((unsigned long)flags),
128 		(void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
129 		(void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
130 		(void *)((unsigned long)(iomapp->iomap_delta)),
131 		(void *)((unsigned long)(iomapp->iomap_bsize)),
132 		(void *)((unsigned long)(iomapp->iomap_bn)),
133 		(void *)(__psint_t)(imapp->br_startoff),
134 		(void *)((unsigned long)(imapp->br_blockcount)),
135 		(void *)(__psint_t)(imapp->br_startblock));
136 }
137 #else
138 #define xfs_iomap_enter_trace(tag, io, offset, count)
139 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
140 #endif
141 
142 #define XFS_WRITEIO_ALIGN(mp,off)	(((off) >> mp->m_writeio_log) \
143 						<< mp->m_writeio_log)
144 #define XFS_STRAT_WRITE_IMAPS	2
145 #define XFS_WRITE_IMAPS		XFS_BMAP_MAX_NMAP
146 
147 STATIC int
148 xfs_imap_to_bmap(
149 	xfs_iocore_t	*io,
150 	xfs_off_t	offset,
151 	xfs_bmbt_irec_t *imap,
152 	xfs_iomap_t	*iomapp,
153 	int		imaps,			/* Number of imap entries */
154 	int		iomaps,			/* Number of iomap entries */
155 	int		flags)
156 {
157 	xfs_mount_t	*mp;
158 	xfs_fsize_t	nisize;
159 	int		pbm;
160 	xfs_fsblock_t	start_block;
161 
162 	mp = io->io_mount;
163 	nisize = XFS_SIZE(mp, io);
164 	if (io->io_new_size > nisize)
165 		nisize = io->io_new_size;
166 
167 	for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
168 		iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
169 		iomapp->iomap_delta = offset - iomapp->iomap_offset;
170 		iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
171 		iomapp->iomap_flags = flags;
172 
173 		if (io->io_flags & XFS_IOCORE_RT) {
174 			iomapp->iomap_flags |= IOMAP_REALTIME;
175 			iomapp->iomap_target = mp->m_rtdev_targp;
176 		} else {
177 			iomapp->iomap_target = mp->m_ddev_targp;
178 		}
179 		start_block = imap->br_startblock;
180 		if (start_block == HOLESTARTBLOCK) {
181 			iomapp->iomap_bn = IOMAP_DADDR_NULL;
182 			iomapp->iomap_flags |= IOMAP_HOLE;
183 		} else if (start_block == DELAYSTARTBLOCK) {
184 			iomapp->iomap_bn = IOMAP_DADDR_NULL;
185 			iomapp->iomap_flags |= IOMAP_DELAY;
186 		} else {
187 			iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
188 			if (ISUNWRITTEN(imap))
189 				iomapp->iomap_flags |= IOMAP_UNWRITTEN;
190 		}
191 
192 		if ((iomapp->iomap_offset + iomapp->iomap_bsize) >= nisize) {
193 			iomapp->iomap_flags |= IOMAP_EOF;
194 		}
195 
196 		offset += iomapp->iomap_bsize - iomapp->iomap_delta;
197 	}
198 	return pbm;	/* Return the number filled */
199 }
200 
201 int
202 xfs_iomap(
203 	xfs_iocore_t	*io,
204 	xfs_off_t	offset,
205 	ssize_t		count,
206 	int		flags,
207 	xfs_iomap_t	*iomapp,
208 	int		*niomaps)
209 {
210 	xfs_mount_t	*mp = io->io_mount;
211 	xfs_fileoff_t	offset_fsb, end_fsb;
212 	int		error = 0;
213 	int		lockmode = 0;
214 	xfs_bmbt_irec_t	imap;
215 	int		nimaps = 1;
216 	int		bmapi_flags = 0;
217 	int		iomap_flags = 0;
218 
219 	if (XFS_FORCED_SHUTDOWN(mp))
220 		return XFS_ERROR(EIO);
221 
222 	switch (flags &
223 		(BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
224 		 BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
225 	case BMAPI_READ:
226 		xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
227 		lockmode = XFS_LCK_MAP_SHARED(mp, io);
228 		bmapi_flags = XFS_BMAPI_ENTIRE;
229 		break;
230 	case BMAPI_WRITE:
231 		xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
232 		lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
233 		if (flags & BMAPI_IGNSTATE)
234 			bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
235 		XFS_ILOCK(mp, io, lockmode);
236 		break;
237 	case BMAPI_ALLOCATE:
238 		xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
239 		lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
240 		bmapi_flags = XFS_BMAPI_ENTIRE;
241 		/* Attempt non-blocking lock */
242 		if (flags & BMAPI_TRYLOCK) {
243 			if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
244 				return XFS_ERROR(EAGAIN);
245 		} else {
246 			XFS_ILOCK(mp, io, lockmode);
247 		}
248 		break;
249 	case BMAPI_UNWRITTEN:
250 		goto phase2;
251 	case BMAPI_DEVICE:
252 		lockmode = XFS_LCK_MAP_SHARED(mp, io);
253 		iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
254 			mp->m_rtdev_targp : mp->m_ddev_targp;
255 		error = 0;
256 		*niomaps = 1;
257 		goto out;
258 	default:
259 		BUG();
260 	}
261 
262 	ASSERT(offset <= mp->m_maxioffset);
263 	if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
264 		count = mp->m_maxioffset - offset;
265 	end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
266 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
267 
268 	error = XFS_BMAPI(mp, NULL, io, offset_fsb,
269 			(xfs_filblks_t)(end_fsb - offset_fsb),
270 			bmapi_flags,  NULL, 0, &imap,
271 			&nimaps, NULL);
272 
273 	if (error)
274 		goto out;
275 
276 phase2:
277 	switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
278 	case BMAPI_WRITE:
279 		/* If we found an extent, return it */
280 		if (nimaps &&
281 		    (imap.br_startblock != HOLESTARTBLOCK) &&
282 		    (imap.br_startblock != DELAYSTARTBLOCK)) {
283 			xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
284 					offset, count, iomapp, &imap, flags);
285 			break;
286 		}
287 
288 		if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
289 			error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
290 					count, flags, &imap, &nimaps, nimaps);
291 		} else {
292 			error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
293 					flags, &imap, &nimaps);
294 		}
295 		if (!error) {
296 			xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
297 					offset, count, iomapp, &imap, flags);
298 		}
299 		iomap_flags = IOMAP_NEW;
300 		break;
301 	case BMAPI_ALLOCATE:
302 		/* If we found an extent, return it */
303 		XFS_IUNLOCK(mp, io, lockmode);
304 		lockmode = 0;
305 
306 		if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
307 			xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
308 					offset, count, iomapp, &imap, flags);
309 			break;
310 		}
311 
312 		error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
313 						 &imap, &nimaps);
314 		break;
315 	case BMAPI_UNWRITTEN:
316 		lockmode = 0;
317 		error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
318 		nimaps = 0;
319 		break;
320 	}
321 
322 	if (nimaps) {
323 		*niomaps = xfs_imap_to_bmap(io, offset, &imap,
324 					    iomapp, nimaps, *niomaps, iomap_flags);
325 	} else if (niomaps) {
326 		*niomaps = 0;
327 	}
328 
329 out:
330 	if (lockmode)
331 		XFS_IUNLOCK(mp, io, lockmode);
332 	return XFS_ERROR(error);
333 }
334 
335 STATIC int
336 xfs_flush_space(
337 	xfs_inode_t	*ip,
338 	int		*fsynced,
339 	int		*ioflags)
340 {
341 	switch (*fsynced) {
342 	case 0:
343 		if (ip->i_delayed_blks) {
344 			xfs_iunlock(ip, XFS_ILOCK_EXCL);
345 			xfs_flush_inode(ip);
346 			xfs_ilock(ip, XFS_ILOCK_EXCL);
347 			*fsynced = 1;
348 		} else {
349 			*ioflags |= BMAPI_SYNC;
350 			*fsynced = 2;
351 		}
352 		return 0;
353 	case 1:
354 		*fsynced = 2;
355 		*ioflags |= BMAPI_SYNC;
356 		return 0;
357 	case 2:
358 		xfs_iunlock(ip, XFS_ILOCK_EXCL);
359 		xfs_flush_device(ip);
360 		xfs_ilock(ip, XFS_ILOCK_EXCL);
361 		*fsynced = 3;
362 		return 0;
363 	}
364 	return 1;
365 }
366 
367 int
368 xfs_iomap_write_direct(
369 	xfs_inode_t	*ip,
370 	xfs_off_t	offset,
371 	size_t		count,
372 	int		flags,
373 	xfs_bmbt_irec_t *ret_imap,
374 	int		*nmaps,
375 	int		found)
376 {
377 	xfs_mount_t	*mp = ip->i_mount;
378 	xfs_iocore_t	*io = &ip->i_iocore;
379 	xfs_fileoff_t	offset_fsb;
380 	xfs_fileoff_t	last_fsb;
381 	xfs_filblks_t	count_fsb;
382 	xfs_fsize_t	isize;
383 	xfs_fsblock_t	firstfsb;
384 	int		nimaps, maps;
385 	int		error;
386 	int		bmapi_flag;
387 	int		quota_flag;
388 	int		rt;
389 	xfs_trans_t	*tp;
390 	xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS], *imapp;
391 	xfs_bmap_free_t free_list;
392 	int		aeof;
393 	xfs_filblks_t	qblocks, resblks;
394 	int		committed;
395 	int		resrtextents;
396 
397 	/*
398 	 * Make sure that the dquots are there. This doesn't hold
399 	 * the ilock across a disk read.
400 	 */
401 	error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
402 	if (error)
403 		return XFS_ERROR(error);
404 
405 	maps = min(XFS_WRITE_IMAPS, *nmaps);
406 	nimaps = maps;
407 
408 	isize = ip->i_d.di_size;
409 	aeof = (offset + count) > isize;
410 
411 	if (io->io_new_size > isize)
412 		isize = io->io_new_size;
413 
414 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
415 	last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
416 	count_fsb = last_fsb - offset_fsb;
417 	if (found && (ret_imap->br_startblock == HOLESTARTBLOCK)) {
418 		xfs_fileoff_t	map_last_fsb;
419 
420 		map_last_fsb = ret_imap->br_blockcount + ret_imap->br_startoff;
421 		if (map_last_fsb < last_fsb) {
422 			last_fsb = map_last_fsb;
423 			count_fsb = last_fsb - offset_fsb;
424 		}
425 		ASSERT(count_fsb > 0);
426 	}
427 
428 	/*
429 	 * Determine if reserving space on the data or realtime partition.
430 	 */
431 	if ((rt = XFS_IS_REALTIME_INODE(ip))) {
432 		xfs_extlen_t	extsz;
433 
434 		if (!(extsz = ip->i_d.di_extsize))
435 			extsz = mp->m_sb.sb_rextsize;
436 		resrtextents = qblocks = (count_fsb + extsz - 1);
437 		do_div(resrtextents, mp->m_sb.sb_rextsize);
438 		resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
439 		quota_flag = XFS_QMOPT_RES_RTBLKS;
440 	} else {
441 		resrtextents = 0;
442 		resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, count_fsb);
443 		quota_flag = XFS_QMOPT_RES_REGBLKS;
444 	}
445 
446 	/*
447 	 * Allocate and setup the transaction
448 	 */
449 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
450 	tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
451 	error = xfs_trans_reserve(tp, resblks,
452 			XFS_WRITE_LOG_RES(mp), resrtextents,
453 			XFS_TRANS_PERM_LOG_RES,
454 			XFS_WRITE_LOG_COUNT);
455 
456 	/*
457 	 * Check for running out of space, note: need lock to return
458 	 */
459 	if (error)
460 		xfs_trans_cancel(tp, 0);
461 	xfs_ilock(ip, XFS_ILOCK_EXCL);
462 	if (error)
463 		goto error_out;
464 
465 	if (XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag)) {
466 		error = (EDQUOT);
467 		goto error1;
468 	}
469 
470 	bmapi_flag = XFS_BMAPI_WRITE;
471 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
472 	xfs_trans_ihold(tp, ip);
473 
474 	if (!(flags & BMAPI_MMAP) && (offset < ip->i_d.di_size || rt))
475 		bmapi_flag |= XFS_BMAPI_PREALLOC;
476 
477 	/*
478 	 * Issue the bmapi() call to allocate the blocks
479 	 */
480 	XFS_BMAP_INIT(&free_list, &firstfsb);
481 	nimaps = 1;
482 	imapp = &imap[0];
483 	error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
484 		bmapi_flag, &firstfsb, 0, imapp, &nimaps, &free_list);
485 	if (error)
486 		goto error0;
487 
488 	/*
489 	 * Complete the transaction
490 	 */
491 	error = xfs_bmap_finish(&tp, &free_list, firstfsb, &committed);
492 	if (error)
493 		goto error0;
494 	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
495 	if (error)
496 		goto error_out;
497 
498 	/*
499 	 * Copy any maps to caller's array and return any error.
500 	 */
501 	if (nimaps == 0) {
502 		error = (ENOSPC);
503 		goto error_out;
504 	}
505 
506 	*ret_imap = imap[0];
507 	*nmaps = 1;
508 	if ( !(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
509                 cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
510                         "start_block : %llx start_off : %llx blkcnt : %llx "
511                         "extent-state : %x \n",
512                         (ip->i_mount)->m_fsname,
513                         (long long)ip->i_ino,
514                         ret_imap->br_startblock, ret_imap->br_startoff,
515                         ret_imap->br_blockcount,ret_imap->br_state);
516         }
517 	return 0;
518 
519 error0:	/* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
520 	xfs_bmap_cancel(&free_list);
521 	XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
522 
523 error1:	/* Just cancel transaction */
524 	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
525 	*nmaps = 0;	/* nothing set-up here */
526 
527 error_out:
528 	return XFS_ERROR(error);
529 }
530 
531 int
532 xfs_iomap_write_delay(
533 	xfs_inode_t	*ip,
534 	xfs_off_t	offset,
535 	size_t		count,
536 	int		ioflag,
537 	xfs_bmbt_irec_t *ret_imap,
538 	int		*nmaps)
539 {
540 	xfs_mount_t	*mp = ip->i_mount;
541 	xfs_iocore_t	*io = &ip->i_iocore;
542 	xfs_fileoff_t	offset_fsb;
543 	xfs_fileoff_t	last_fsb;
544 	xfs_fsize_t	isize;
545 	xfs_fsblock_t	firstblock;
546 	int		nimaps;
547 	int		error;
548 	xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
549 	int		aeof;
550 	int		fsynced = 0;
551 
552 	ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
553 
554 	/*
555 	 * Make sure that the dquots are there. This doesn't hold
556 	 * the ilock across a disk read.
557 	 */
558 
559 	error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
560 	if (error)
561 		return XFS_ERROR(error);
562 
563 retry:
564 	isize = ip->i_d.di_size;
565 	if (io->io_new_size > isize) {
566 		isize = io->io_new_size;
567 	}
568 
569 	aeof = 0;
570 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
571 	last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
572 	/*
573 	 * If the caller is doing a write at the end of the file,
574 	 * then extend the allocation (and the buffer used for the write)
575 	 * out to the file system's write iosize.  We clean up any extra
576 	 * space left over when the file is closed in xfs_inactive().
577 	 *
578 	 * For sync writes, we are flushing delayed allocate space to
579 	 * try to make additional space available for allocation near
580 	 * the filesystem full boundary - preallocation hurts in that
581 	 * situation, of course.
582 	 */
583 	if (!(ioflag & BMAPI_SYNC) && ((offset + count) > ip->i_d.di_size)) {
584 		xfs_off_t	aligned_offset;
585 		xfs_filblks_t   count_fsb;
586 		unsigned int	iosize;
587 		xfs_fileoff_t	ioalign;
588 		int		n;
589 		xfs_fileoff_t   start_fsb;
590 
591 		/*
592 		 * If there are any real blocks past eof, then don't
593 		 * do any speculative allocation.
594 		 */
595 		start_fsb = XFS_B_TO_FSBT(mp,
596 					((xfs_ufsize_t)(offset + count - 1)));
597 		count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
598 		while (count_fsb > 0) {
599 			nimaps = XFS_WRITE_IMAPS;
600 			error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb,
601 					0, &firstblock, 0, imap, &nimaps, NULL);
602 			if (error) {
603 				return error;
604 			}
605 			for (n = 0; n < nimaps; n++) {
606 				if ( !(io->io_flags & XFS_IOCORE_RT)  &&
607 					!imap[n].br_startblock) {
608 					cmn_err(CE_PANIC,"Access to block "
609 						"zero:  fs <%s> inode: %lld "
610 						"start_block : %llx start_off "
611 						": %llx blkcnt : %llx "
612 						"extent-state : %x \n",
613 						(ip->i_mount)->m_fsname,
614 						(long long)ip->i_ino,
615 						imap[n].br_startblock,
616 						imap[n].br_startoff,
617 						imap[n].br_blockcount,
618 						imap[n].br_state);
619         			}
620 				if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
621 				    (imap[n].br_startblock != DELAYSTARTBLOCK)) {
622 					goto write_map;
623 				}
624 				start_fsb += imap[n].br_blockcount;
625 				count_fsb -= imap[n].br_blockcount;
626 			}
627 		}
628 		iosize = mp->m_writeio_blocks;
629 		aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
630 		ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
631 		last_fsb = ioalign + iosize;
632 		aeof = 1;
633 	}
634 write_map:
635 	nimaps = XFS_WRITE_IMAPS;
636 	firstblock = NULLFSBLOCK;
637 
638 	/*
639 	 * If mounted with the "-o swalloc" option, roundup the allocation
640 	 * request to a stripe width boundary if the file size is >=
641 	 * stripe width and we are allocating past the allocation eof.
642 	 */
643 	if (!(io->io_flags & XFS_IOCORE_RT) && mp->m_swidth
644 	    && (mp->m_flags & XFS_MOUNT_SWALLOC)
645 	    && (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)) && aeof) {
646 		int eof;
647 		xfs_fileoff_t new_last_fsb;
648 
649 		new_last_fsb = roundup_64(last_fsb, mp->m_swidth);
650 		error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
651 		if (error) {
652 			return error;
653 		}
654 		if (eof) {
655 			last_fsb = new_last_fsb;
656 		}
657 	/*
658 	 * Roundup the allocation request to a stripe unit (m_dalign) boundary
659 	 * if the file size is >= stripe unit size, and we are allocating past
660 	 * the allocation eof.
661 	 */
662 	} else if (!(io->io_flags & XFS_IOCORE_RT) && mp->m_dalign &&
663 		   (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)) && aeof) {
664 		int eof;
665 		xfs_fileoff_t new_last_fsb;
666 		new_last_fsb = roundup_64(last_fsb, mp->m_dalign);
667 		error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
668 		if (error) {
669 			return error;
670 		}
671 		if (eof) {
672 			last_fsb = new_last_fsb;
673 		}
674 	/*
675 	 * Round up the allocation request to a real-time extent boundary
676 	 * if the file is on the real-time subvolume.
677 	 */
678 	} else if (io->io_flags & XFS_IOCORE_RT && aeof) {
679 		int eof;
680 		xfs_fileoff_t new_last_fsb;
681 
682 		new_last_fsb = roundup_64(last_fsb, mp->m_sb.sb_rextsize);
683 		error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
684 		if (error) {
685 			return error;
686 		}
687 		if (eof)
688 			last_fsb = new_last_fsb;
689 	}
690 	error = xfs_bmapi(NULL, ip, offset_fsb,
691 			  (xfs_filblks_t)(last_fsb - offset_fsb),
692 			  XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
693 			  XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
694 			  &nimaps, NULL);
695 	/*
696 	 * This can be EDQUOT, if nimaps == 0
697 	 */
698 	if (error && (error != ENOSPC)) {
699 		return XFS_ERROR(error);
700 	}
701 	/*
702 	 * If bmapi returned us nothing, and if we didn't get back EDQUOT,
703 	 * then we must have run out of space.
704 	 */
705 	if (nimaps == 0) {
706 		xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
707 					io, offset, count);
708 		if (xfs_flush_space(ip, &fsynced, &ioflag))
709 			return XFS_ERROR(ENOSPC);
710 
711 		error = 0;
712 		goto retry;
713 	}
714 
715 	*ret_imap = imap[0];
716 	*nmaps = 1;
717 	if ( !(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
718 		cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
719                         "start_block : %llx start_off : %llx blkcnt : %llx "
720                         "extent-state : %x \n",
721                         (ip->i_mount)->m_fsname,
722                         (long long)ip->i_ino,
723                         ret_imap->br_startblock, ret_imap->br_startoff,
724                         ret_imap->br_blockcount,ret_imap->br_state);
725 	}
726 	return 0;
727 }
728 
729 /*
730  * Pass in a delayed allocate extent, convert it to real extents;
731  * return to the caller the extent we create which maps on top of
732  * the originating callers request.
733  *
734  * Called without a lock on the inode.
735  */
736 int
737 xfs_iomap_write_allocate(
738 	xfs_inode_t	*ip,
739 	xfs_off_t	offset,
740 	size_t		count,
741 	xfs_bmbt_irec_t *map,
742 	int		*retmap)
743 {
744 	xfs_mount_t	*mp = ip->i_mount;
745 	xfs_iocore_t    *io = &ip->i_iocore;
746 	xfs_fileoff_t	offset_fsb, last_block;
747 	xfs_fileoff_t	end_fsb, map_start_fsb;
748 	xfs_fsblock_t	first_block;
749 	xfs_bmap_free_t	free_list;
750 	xfs_filblks_t	count_fsb;
751 	xfs_bmbt_irec_t	imap[XFS_STRAT_WRITE_IMAPS];
752 	xfs_trans_t	*tp;
753 	int		i, nimaps, committed;
754 	int		error = 0;
755 	int		nres;
756 
757 	*retmap = 0;
758 
759 	/*
760 	 * Make sure that the dquots are there.
761 	 */
762 	if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
763 		return XFS_ERROR(error);
764 
765 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
766 	count_fsb = map->br_blockcount;
767 	map_start_fsb = map->br_startoff;
768 
769 	XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
770 
771 	while (count_fsb != 0) {
772 		/*
773 		 * Set up a transaction with which to allocate the
774 		 * backing store for the file.  Do allocations in a
775 		 * loop until we get some space in the range we are
776 		 * interested in.  The other space that might be allocated
777 		 * is in the delayed allocation extent on which we sit
778 		 * but before our buffer starts.
779 		 */
780 
781 		nimaps = 0;
782 		while (nimaps == 0) {
783 			tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
784 			nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
785 			error = xfs_trans_reserve(tp, nres,
786 					XFS_WRITE_LOG_RES(mp),
787 					0, XFS_TRANS_PERM_LOG_RES,
788 					XFS_WRITE_LOG_COUNT);
789 			if (error == ENOSPC) {
790 				error = xfs_trans_reserve(tp, 0,
791 						XFS_WRITE_LOG_RES(mp),
792 						0,
793 						XFS_TRANS_PERM_LOG_RES,
794 						XFS_WRITE_LOG_COUNT);
795 			}
796 			if (error) {
797 				xfs_trans_cancel(tp, 0);
798 				return XFS_ERROR(error);
799 			}
800 			xfs_ilock(ip, XFS_ILOCK_EXCL);
801 			xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
802 			xfs_trans_ihold(tp, ip);
803 
804 			XFS_BMAP_INIT(&free_list, &first_block);
805 
806 			nimaps = XFS_STRAT_WRITE_IMAPS;
807 			/*
808 			 * Ensure we don't go beyond eof - it is possible
809 			 * the extents changed since we did the read call,
810 			 * we dropped the ilock in the interim.
811 			 */
812 
813 			end_fsb = XFS_B_TO_FSB(mp, ip->i_d.di_size);
814 			xfs_bmap_last_offset(NULL, ip, &last_block,
815 				XFS_DATA_FORK);
816 			last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
817 			if ((map_start_fsb + count_fsb) > last_block) {
818 				count_fsb = last_block - map_start_fsb;
819 				if (count_fsb == 0) {
820 					error = EAGAIN;
821 					goto trans_cancel;
822 				}
823 			}
824 
825 			/* Go get the actual blocks */
826 			error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
827 					XFS_BMAPI_WRITE, &first_block, 1,
828 					imap, &nimaps, &free_list);
829 			if (error)
830 				goto trans_cancel;
831 
832 			error = xfs_bmap_finish(&tp, &free_list,
833 					first_block, &committed);
834 			if (error)
835 				goto trans_cancel;
836 
837 			error = xfs_trans_commit(tp,
838 					XFS_TRANS_RELEASE_LOG_RES, NULL);
839 			if (error)
840 				goto error0;
841 
842 			xfs_iunlock(ip, XFS_ILOCK_EXCL);
843 		}
844 
845 		/*
846 		 * See if we were able to allocate an extent that
847 		 * covers at least part of the callers request
848 		 */
849 
850 		for (i = 0; i < nimaps; i++) {
851 			if ( !(io->io_flags & XFS_IOCORE_RT)  &&
852 				!imap[i].br_startblock) {
853 				cmn_err(CE_PANIC,"Access to block zero:  "
854 					"fs <%s> inode: %lld "
855 					"start_block : %llx start_off : %llx "
856 					"blkcnt : %llx extent-state : %x \n",
857 					(ip->i_mount)->m_fsname,
858 					(long long)ip->i_ino,
859 					imap[i].br_startblock,
860 					imap[i].br_startoff,
861 				        imap[i].br_blockcount,imap[i].br_state);
862                         }
863 			if ((offset_fsb >= imap[i].br_startoff) &&
864 			    (offset_fsb < (imap[i].br_startoff +
865 					   imap[i].br_blockcount))) {
866 				*map = imap[i];
867 				*retmap = 1;
868 				XFS_STATS_INC(xs_xstrat_quick);
869 				return 0;
870 			}
871 			count_fsb -= imap[i].br_blockcount;
872 		}
873 
874 		/* So far we have not mapped the requested part of the
875 		 * file, just surrounding data, try again.
876 		 */
877 		nimaps--;
878 		map_start_fsb = imap[nimaps].br_startoff +
879 				imap[nimaps].br_blockcount;
880 	}
881 
882 trans_cancel:
883 	xfs_bmap_cancel(&free_list);
884 	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
885 error0:
886 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
887 	return XFS_ERROR(error);
888 }
889 
890 int
891 xfs_iomap_write_unwritten(
892 	xfs_inode_t	*ip,
893 	xfs_off_t	offset,
894 	size_t		count)
895 {
896 	xfs_mount_t	*mp = ip->i_mount;
897 	xfs_iocore_t    *io = &ip->i_iocore;
898 	xfs_trans_t	*tp;
899 	xfs_fileoff_t	offset_fsb;
900 	xfs_filblks_t	count_fsb;
901 	xfs_filblks_t	numblks_fsb;
902 	xfs_bmbt_irec_t	imap;
903 	int		committed;
904 	int		error;
905 	int		nres;
906 	int		nimaps;
907 	xfs_fsblock_t	firstfsb;
908 	xfs_bmap_free_t	free_list;
909 
910 	xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN,
911 				&ip->i_iocore, offset, count);
912 
913 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
914 	count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
915 	count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
916 
917 	do {
918 		nres = XFS_DIOSTRAT_SPACE_RES(mp, 0);
919 
920 		/*
921 		 * set up a transaction to convert the range of extents
922 		 * from unwritten to real. Do allocations in a loop until
923 		 * we have covered the range passed in.
924 		 */
925 
926 		tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
927 		error = xfs_trans_reserve(tp, nres,
928 				XFS_WRITE_LOG_RES(mp), 0,
929 				XFS_TRANS_PERM_LOG_RES,
930 				XFS_WRITE_LOG_COUNT);
931 		if (error) {
932 			xfs_trans_cancel(tp, 0);
933 			goto error0;
934 		}
935 
936 		xfs_ilock(ip, XFS_ILOCK_EXCL);
937 		xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
938 		xfs_trans_ihold(tp, ip);
939 
940 		/*
941 		 * Modify the unwritten extent state of the buffer.
942 		 */
943 		XFS_BMAP_INIT(&free_list, &firstfsb);
944 		nimaps = 1;
945 		error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
946 				  XFS_BMAPI_WRITE, &firstfsb,
947 				  1, &imap, &nimaps, &free_list);
948 		if (error)
949 			goto error_on_bmapi_transaction;
950 
951 		error = xfs_bmap_finish(&(tp), &(free_list),
952 				firstfsb, &committed);
953 		if (error)
954 			goto error_on_bmapi_transaction;
955 
956 		error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
957 		xfs_iunlock(ip, XFS_ILOCK_EXCL);
958 		if (error)
959 			goto error0;
960 
961 		if ( !(io->io_flags & XFS_IOCORE_RT)  && !imap.br_startblock) {
962 			cmn_err(CE_PANIC,"Access to block zero:  fs <%s> "
963 				"inode: %lld start_block : %llx start_off : "
964 				"%llx blkcnt : %llx extent-state : %x \n",
965 				(ip->i_mount)->m_fsname,
966 				(long long)ip->i_ino,
967 				imap.br_startblock,imap.br_startoff,
968 				imap.br_blockcount,imap.br_state);
969         	}
970 
971 		if ((numblks_fsb = imap.br_blockcount) == 0) {
972 			/*
973 			 * The numblks_fsb value should always get
974 			 * smaller, otherwise the loop is stuck.
975 			 */
976 			ASSERT(imap.br_blockcount);
977 			break;
978 		}
979 		offset_fsb += numblks_fsb;
980 		count_fsb -= numblks_fsb;
981 	} while (count_fsb > 0);
982 
983 	return 0;
984 
985 error_on_bmapi_transaction:
986 	xfs_bmap_cancel(&free_list);
987 	xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
988 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
989 error0:
990 	return XFS_ERROR(error);
991 }
992