1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4 * Copyright (c) 2016-2018 Christoph Hellwig.
5 * All Rights Reserved.
6 */
7 #include "xfs.h"
8 #include "xfs_fs.h"
9 #include "xfs_shared.h"
10 #include "xfs_format.h"
11 #include "xfs_log_format.h"
12 #include "xfs_trans_resv.h"
13 #include "xfs_mount.h"
14 #include "xfs_inode.h"
15 #include "xfs_btree.h"
16 #include "xfs_bmap_btree.h"
17 #include "xfs_bmap.h"
18 #include "xfs_bmap_util.h"
19 #include "xfs_errortag.h"
20 #include "xfs_error.h"
21 #include "xfs_trans.h"
22 #include "xfs_trans_space.h"
23 #include "xfs_inode_item.h"
24 #include "xfs_iomap.h"
25 #include "xfs_trace.h"
26 #include "xfs_quota.h"
27 #include "xfs_dquot_item.h"
28 #include "xfs_dquot.h"
29 #include "xfs_reflink.h"
30 #include "xfs_health.h"
31 #include "xfs_rtbitmap.h"
32
33 #define XFS_ALLOC_ALIGN(mp, off) \
34 (((off) >> mp->m_allocsize_log) << mp->m_allocsize_log)
35
36 static int
xfs_alert_fsblock_zero(xfs_inode_t * ip,xfs_bmbt_irec_t * imap)37 xfs_alert_fsblock_zero(
38 xfs_inode_t *ip,
39 xfs_bmbt_irec_t *imap)
40 {
41 xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO,
42 "Access to block zero in inode %llu "
43 "start_block: %llx start_off: %llx "
44 "blkcnt: %llx extent-state: %x",
45 (unsigned long long)ip->i_ino,
46 (unsigned long long)imap->br_startblock,
47 (unsigned long long)imap->br_startoff,
48 (unsigned long long)imap->br_blockcount,
49 imap->br_state);
50 xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
51 return -EFSCORRUPTED;
52 }
53
54 u64
xfs_iomap_inode_sequence(struct xfs_inode * ip,u16 iomap_flags)55 xfs_iomap_inode_sequence(
56 struct xfs_inode *ip,
57 u16 iomap_flags)
58 {
59 u64 cookie = 0;
60
61 if (iomap_flags & IOMAP_F_XATTR)
62 return READ_ONCE(ip->i_af.if_seq);
63 if ((iomap_flags & IOMAP_F_SHARED) && ip->i_cowfp)
64 cookie = (u64)READ_ONCE(ip->i_cowfp->if_seq) << 32;
65 return cookie | READ_ONCE(ip->i_df.if_seq);
66 }
67
68 /*
69 * Check that the iomap passed to us is still valid for the given offset and
70 * length.
71 */
72 static bool
xfs_iomap_valid(struct inode * inode,const struct iomap * iomap)73 xfs_iomap_valid(
74 struct inode *inode,
75 const struct iomap *iomap)
76 {
77 struct xfs_inode *ip = XFS_I(inode);
78
79 if (iomap->validity_cookie !=
80 xfs_iomap_inode_sequence(ip, iomap->flags)) {
81 trace_xfs_iomap_invalid(ip, iomap);
82 return false;
83 }
84
85 XFS_ERRORTAG_DELAY(ip->i_mount, XFS_ERRTAG_WRITE_DELAY_MS);
86 return true;
87 }
88
89 static const struct iomap_folio_ops xfs_iomap_folio_ops = {
90 .iomap_valid = xfs_iomap_valid,
91 };
92
93 int
xfs_bmbt_to_iomap(struct xfs_inode * ip,struct iomap * iomap,struct xfs_bmbt_irec * imap,unsigned int mapping_flags,u16 iomap_flags,u64 sequence_cookie)94 xfs_bmbt_to_iomap(
95 struct xfs_inode *ip,
96 struct iomap *iomap,
97 struct xfs_bmbt_irec *imap,
98 unsigned int mapping_flags,
99 u16 iomap_flags,
100 u64 sequence_cookie)
101 {
102 struct xfs_mount *mp = ip->i_mount;
103 struct xfs_buftarg *target = xfs_inode_buftarg(ip);
104
105 if (unlikely(!xfs_valid_startblock(ip, imap->br_startblock))) {
106 xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
107 return xfs_alert_fsblock_zero(ip, imap);
108 }
109
110 if (imap->br_startblock == HOLESTARTBLOCK) {
111 iomap->addr = IOMAP_NULL_ADDR;
112 iomap->type = IOMAP_HOLE;
113 } else if (imap->br_startblock == DELAYSTARTBLOCK ||
114 isnullstartblock(imap->br_startblock)) {
115 iomap->addr = IOMAP_NULL_ADDR;
116 iomap->type = IOMAP_DELALLOC;
117 } else {
118 iomap->addr = BBTOB(xfs_fsb_to_db(ip, imap->br_startblock));
119 if (mapping_flags & IOMAP_DAX)
120 iomap->addr += target->bt_dax_part_off;
121
122 if (imap->br_state == XFS_EXT_UNWRITTEN)
123 iomap->type = IOMAP_UNWRITTEN;
124 else
125 iomap->type = IOMAP_MAPPED;
126
127 }
128 iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff);
129 iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount);
130 if (mapping_flags & IOMAP_DAX)
131 iomap->dax_dev = target->bt_daxdev;
132 else
133 iomap->bdev = target->bt_bdev;
134 iomap->flags = iomap_flags;
135
136 if (xfs_ipincount(ip) &&
137 (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
138 iomap->flags |= IOMAP_F_DIRTY;
139
140 iomap->validity_cookie = sequence_cookie;
141 iomap->folio_ops = &xfs_iomap_folio_ops;
142 return 0;
143 }
144
145 static void
xfs_hole_to_iomap(struct xfs_inode * ip,struct iomap * iomap,xfs_fileoff_t offset_fsb,xfs_fileoff_t end_fsb)146 xfs_hole_to_iomap(
147 struct xfs_inode *ip,
148 struct iomap *iomap,
149 xfs_fileoff_t offset_fsb,
150 xfs_fileoff_t end_fsb)
151 {
152 struct xfs_buftarg *target = xfs_inode_buftarg(ip);
153
154 iomap->addr = IOMAP_NULL_ADDR;
155 iomap->type = IOMAP_HOLE;
156 iomap->offset = XFS_FSB_TO_B(ip->i_mount, offset_fsb);
157 iomap->length = XFS_FSB_TO_B(ip->i_mount, end_fsb - offset_fsb);
158 iomap->bdev = target->bt_bdev;
159 iomap->dax_dev = target->bt_daxdev;
160 }
161
162 static inline xfs_fileoff_t
xfs_iomap_end_fsb(struct xfs_mount * mp,loff_t offset,loff_t count)163 xfs_iomap_end_fsb(
164 struct xfs_mount *mp,
165 loff_t offset,
166 loff_t count)
167 {
168 ASSERT(offset <= mp->m_super->s_maxbytes);
169 return min(XFS_B_TO_FSB(mp, offset + count),
170 XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
171 }
172
173 static xfs_extlen_t
xfs_eof_alignment(struct xfs_inode * ip)174 xfs_eof_alignment(
175 struct xfs_inode *ip)
176 {
177 struct xfs_mount *mp = ip->i_mount;
178 xfs_extlen_t align = 0;
179
180 if (!XFS_IS_REALTIME_INODE(ip)) {
181 /*
182 * Round up the allocation request to a stripe unit
183 * (m_dalign) boundary if the file size is >= stripe unit
184 * size, and we are allocating past the allocation eof.
185 *
186 * If mounted with the "-o swalloc" option the alignment is
187 * increased from the strip unit size to the stripe width.
188 */
189 if (mp->m_swidth && xfs_has_swalloc(mp))
190 align = mp->m_swidth;
191 else if (mp->m_dalign)
192 align = mp->m_dalign;
193
194 if (align && XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, align))
195 align = 0;
196 }
197
198 return align;
199 }
200
201 /*
202 * Check if last_fsb is outside the last extent, and if so grow it to the next
203 * stripe unit boundary.
204 */
205 xfs_fileoff_t
xfs_iomap_eof_align_last_fsb(struct xfs_inode * ip,xfs_fileoff_t end_fsb)206 xfs_iomap_eof_align_last_fsb(
207 struct xfs_inode *ip,
208 xfs_fileoff_t end_fsb)
209 {
210 struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
211 xfs_extlen_t extsz = xfs_get_extsz_hint(ip);
212 xfs_extlen_t align = xfs_eof_alignment(ip);
213 struct xfs_bmbt_irec irec;
214 struct xfs_iext_cursor icur;
215
216 ASSERT(!xfs_need_iread_extents(ifp));
217
218 /*
219 * Always round up the allocation request to the extent hint boundary.
220 */
221 if (extsz) {
222 if (align)
223 align = roundup_64(align, extsz);
224 else
225 align = extsz;
226 }
227
228 if (align) {
229 xfs_fileoff_t aligned_end_fsb = roundup_64(end_fsb, align);
230
231 xfs_iext_last(ifp, &icur);
232 if (!xfs_iext_get_extent(ifp, &icur, &irec) ||
233 aligned_end_fsb >= irec.br_startoff + irec.br_blockcount)
234 return aligned_end_fsb;
235 }
236
237 return end_fsb;
238 }
239
240 int
xfs_iomap_write_direct(struct xfs_inode * ip,xfs_fileoff_t offset_fsb,xfs_fileoff_t count_fsb,unsigned int flags,struct xfs_bmbt_irec * imap,u64 * seq)241 xfs_iomap_write_direct(
242 struct xfs_inode *ip,
243 xfs_fileoff_t offset_fsb,
244 xfs_fileoff_t count_fsb,
245 unsigned int flags,
246 struct xfs_bmbt_irec *imap,
247 u64 *seq)
248 {
249 struct xfs_mount *mp = ip->i_mount;
250 struct xfs_trans *tp;
251 xfs_filblks_t resaligned;
252 int nimaps;
253 unsigned int dblocks, rblocks;
254 bool force = false;
255 int error;
256 int bmapi_flags = XFS_BMAPI_PREALLOC;
257 int nr_exts = XFS_IEXT_ADD_NOSPLIT_CNT;
258
259 ASSERT(count_fsb > 0);
260
261 resaligned = xfs_aligned_fsb_count(offset_fsb, count_fsb,
262 xfs_get_extsz_hint(ip));
263 if (unlikely(XFS_IS_REALTIME_INODE(ip))) {
264 dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
265 rblocks = resaligned;
266 } else {
267 dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
268 rblocks = 0;
269 }
270
271 error = xfs_qm_dqattach(ip);
272 if (error)
273 return error;
274
275 /*
276 * For DAX, we do not allocate unwritten extents, but instead we zero
277 * the block before we commit the transaction. Ideally we'd like to do
278 * this outside the transaction context, but if we commit and then crash
279 * we may not have zeroed the blocks and this will be exposed on
280 * recovery of the allocation. Hence we must zero before commit.
281 *
282 * Further, if we are mapping unwritten extents here, we need to zero
283 * and convert them to written so that we don't need an unwritten extent
284 * callback for DAX. This also means that we need to be able to dip into
285 * the reserve block pool for bmbt block allocation if there is no space
286 * left but we need to do unwritten extent conversion.
287 */
288 if (flags & IOMAP_DAX) {
289 bmapi_flags = XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO;
290 if (imap->br_state == XFS_EXT_UNWRITTEN) {
291 force = true;
292 nr_exts = XFS_IEXT_WRITE_UNWRITTEN_CNT;
293 dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
294 }
295 }
296
297 error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, dblocks,
298 rblocks, force, &tp);
299 if (error)
300 return error;
301
302 error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK, nr_exts);
303 if (error)
304 goto out_trans_cancel;
305
306 /*
307 * From this point onwards we overwrite the imap pointer that the
308 * caller gave to us.
309 */
310 nimaps = 1;
311 error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flags, 0,
312 imap, &nimaps);
313 if (error)
314 goto out_trans_cancel;
315
316 /*
317 * Complete the transaction
318 */
319 error = xfs_trans_commit(tp);
320 if (error)
321 goto out_unlock;
322
323 if (unlikely(!xfs_valid_startblock(ip, imap->br_startblock))) {
324 xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
325 error = xfs_alert_fsblock_zero(ip, imap);
326 }
327
328 out_unlock:
329 *seq = xfs_iomap_inode_sequence(ip, 0);
330 xfs_iunlock(ip, XFS_ILOCK_EXCL);
331 return error;
332
333 out_trans_cancel:
334 xfs_trans_cancel(tp);
335 goto out_unlock;
336 }
337
338 STATIC bool
xfs_quota_need_throttle(struct xfs_inode * ip,xfs_dqtype_t type,xfs_fsblock_t alloc_blocks)339 xfs_quota_need_throttle(
340 struct xfs_inode *ip,
341 xfs_dqtype_t type,
342 xfs_fsblock_t alloc_blocks)
343 {
344 struct xfs_dquot *dq = xfs_inode_dquot(ip, type);
345
346 if (!dq || !xfs_this_quota_on(ip->i_mount, type))
347 return false;
348
349 /* no hi watermark, no throttle */
350 if (!dq->q_prealloc_hi_wmark)
351 return false;
352
353 /* under the lo watermark, no throttle */
354 if (dq->q_blk.reserved + alloc_blocks < dq->q_prealloc_lo_wmark)
355 return false;
356
357 return true;
358 }
359
360 STATIC void
xfs_quota_calc_throttle(struct xfs_inode * ip,xfs_dqtype_t type,xfs_fsblock_t * qblocks,int * qshift,int64_t * qfreesp)361 xfs_quota_calc_throttle(
362 struct xfs_inode *ip,
363 xfs_dqtype_t type,
364 xfs_fsblock_t *qblocks,
365 int *qshift,
366 int64_t *qfreesp)
367 {
368 struct xfs_dquot *dq = xfs_inode_dquot(ip, type);
369 int64_t freesp;
370 int shift = 0;
371
372 /* no dq, or over hi wmark, squash the prealloc completely */
373 if (!dq || dq->q_blk.reserved >= dq->q_prealloc_hi_wmark) {
374 *qblocks = 0;
375 *qfreesp = 0;
376 return;
377 }
378
379 freesp = dq->q_prealloc_hi_wmark - dq->q_blk.reserved;
380 if (freesp < dq->q_low_space[XFS_QLOWSP_5_PCNT]) {
381 shift = 2;
382 if (freesp < dq->q_low_space[XFS_QLOWSP_3_PCNT])
383 shift += 2;
384 if (freesp < dq->q_low_space[XFS_QLOWSP_1_PCNT])
385 shift += 2;
386 }
387
388 if (freesp < *qfreesp)
389 *qfreesp = freesp;
390
391 /* only overwrite the throttle values if we are more aggressive */
392 if ((freesp >> shift) < (*qblocks >> *qshift)) {
393 *qblocks = freesp;
394 *qshift = shift;
395 }
396 }
397
398 static int64_t
xfs_iomap_freesp(struct percpu_counter * counter,uint64_t low_space[XFS_LOWSP_MAX],int * shift)399 xfs_iomap_freesp(
400 struct percpu_counter *counter,
401 uint64_t low_space[XFS_LOWSP_MAX],
402 int *shift)
403 {
404 int64_t freesp;
405
406 freesp = percpu_counter_read_positive(counter);
407 if (freesp < low_space[XFS_LOWSP_5_PCNT]) {
408 *shift = 2;
409 if (freesp < low_space[XFS_LOWSP_4_PCNT])
410 (*shift)++;
411 if (freesp < low_space[XFS_LOWSP_3_PCNT])
412 (*shift)++;
413 if (freesp < low_space[XFS_LOWSP_2_PCNT])
414 (*shift)++;
415 if (freesp < low_space[XFS_LOWSP_1_PCNT])
416 (*shift)++;
417 }
418 return freesp;
419 }
420
421 /*
422 * If we don't have a user specified preallocation size, dynamically increase
423 * the preallocation size as the size of the file grows. Cap the maximum size
424 * at a single extent or less if the filesystem is near full. The closer the
425 * filesystem is to being full, the smaller the maximum preallocation.
426 */
427 STATIC xfs_fsblock_t
xfs_iomap_prealloc_size(struct xfs_inode * ip,int whichfork,loff_t offset,loff_t count,struct xfs_iext_cursor * icur)428 xfs_iomap_prealloc_size(
429 struct xfs_inode *ip,
430 int whichfork,
431 loff_t offset,
432 loff_t count,
433 struct xfs_iext_cursor *icur)
434 {
435 struct xfs_iext_cursor ncur = *icur;
436 struct xfs_bmbt_irec prev, got;
437 struct xfs_mount *mp = ip->i_mount;
438 struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
439 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
440 int64_t freesp;
441 xfs_fsblock_t qblocks;
442 xfs_fsblock_t alloc_blocks = 0;
443 xfs_extlen_t plen;
444 int shift = 0;
445 int qshift = 0;
446
447 /*
448 * As an exception we don't do any preallocation at all if the file is
449 * smaller than the minimum preallocation and we are using the default
450 * dynamic preallocation scheme, as it is likely this is the only write
451 * to the file that is going to be done.
452 */
453 if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_allocsize_blocks))
454 return 0;
455
456 /*
457 * Use the minimum preallocation size for small files or if we are
458 * writing right after a hole.
459 */
460 if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) ||
461 !xfs_iext_prev_extent(ifp, &ncur, &prev) ||
462 prev.br_startoff + prev.br_blockcount < offset_fsb)
463 return mp->m_allocsize_blocks;
464
465 /*
466 * Take the size of the preceding data extents as the basis for the
467 * preallocation size. Note that we don't care if the previous extents
468 * are written or not.
469 */
470 plen = prev.br_blockcount;
471 while (xfs_iext_prev_extent(ifp, &ncur, &got)) {
472 if (plen > XFS_MAX_BMBT_EXTLEN / 2 ||
473 isnullstartblock(got.br_startblock) ||
474 got.br_startoff + got.br_blockcount != prev.br_startoff ||
475 got.br_startblock + got.br_blockcount != prev.br_startblock)
476 break;
477 plen += got.br_blockcount;
478 prev = got;
479 }
480
481 /*
482 * If the size of the extents is greater than half the maximum extent
483 * length, then use the current offset as the basis. This ensures that
484 * for large files the preallocation size always extends to
485 * XFS_BMBT_MAX_EXTLEN rather than falling short due to things like stripe
486 * unit/width alignment of real extents.
487 */
488 alloc_blocks = plen * 2;
489 if (alloc_blocks > XFS_MAX_BMBT_EXTLEN)
490 alloc_blocks = XFS_B_TO_FSB(mp, offset);
491 qblocks = alloc_blocks;
492
493 /*
494 * XFS_BMBT_MAX_EXTLEN is not a power of two value but we round the prealloc
495 * down to the nearest power of two value after throttling. To prevent
496 * the round down from unconditionally reducing the maximum supported
497 * prealloc size, we round up first, apply appropriate throttling, round
498 * down and cap the value to XFS_BMBT_MAX_EXTLEN.
499 */
500 alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(XFS_MAX_BMBT_EXTLEN),
501 alloc_blocks);
502
503 if (unlikely(XFS_IS_REALTIME_INODE(ip)))
504 freesp = xfs_rtx_to_rtb(mp,
505 xfs_iomap_freesp(&mp->m_frextents,
506 mp->m_low_rtexts, &shift));
507 else
508 freesp = xfs_iomap_freesp(&mp->m_fdblocks, mp->m_low_space,
509 &shift);
510
511 /*
512 * Check each quota to cap the prealloc size, provide a shift value to
513 * throttle with and adjust amount of available space.
514 */
515 if (xfs_quota_need_throttle(ip, XFS_DQTYPE_USER, alloc_blocks))
516 xfs_quota_calc_throttle(ip, XFS_DQTYPE_USER, &qblocks, &qshift,
517 &freesp);
518 if (xfs_quota_need_throttle(ip, XFS_DQTYPE_GROUP, alloc_blocks))
519 xfs_quota_calc_throttle(ip, XFS_DQTYPE_GROUP, &qblocks, &qshift,
520 &freesp);
521 if (xfs_quota_need_throttle(ip, XFS_DQTYPE_PROJ, alloc_blocks))
522 xfs_quota_calc_throttle(ip, XFS_DQTYPE_PROJ, &qblocks, &qshift,
523 &freesp);
524
525 /*
526 * The final prealloc size is set to the minimum of free space available
527 * in each of the quotas and the overall filesystem.
528 *
529 * The shift throttle value is set to the maximum value as determined by
530 * the global low free space values and per-quota low free space values.
531 */
532 alloc_blocks = min(alloc_blocks, qblocks);
533 shift = max(shift, qshift);
534
535 if (shift)
536 alloc_blocks >>= shift;
537 /*
538 * rounddown_pow_of_two() returns an undefined result if we pass in
539 * alloc_blocks = 0.
540 */
541 if (alloc_blocks)
542 alloc_blocks = rounddown_pow_of_two(alloc_blocks);
543 if (alloc_blocks > XFS_MAX_BMBT_EXTLEN)
544 alloc_blocks = XFS_MAX_BMBT_EXTLEN;
545
546 /*
547 * If we are still trying to allocate more space than is
548 * available, squash the prealloc hard. This can happen if we
549 * have a large file on a small filesystem and the above
550 * lowspace thresholds are smaller than XFS_BMBT_MAX_EXTLEN.
551 */
552 while (alloc_blocks && alloc_blocks >= freesp)
553 alloc_blocks >>= 4;
554 if (alloc_blocks < mp->m_allocsize_blocks)
555 alloc_blocks = mp->m_allocsize_blocks;
556 trace_xfs_iomap_prealloc_size(ip, alloc_blocks, shift,
557 mp->m_allocsize_blocks);
558 return alloc_blocks;
559 }
560
561 int
xfs_iomap_write_unwritten(xfs_inode_t * ip,xfs_off_t offset,xfs_off_t count,bool update_isize)562 xfs_iomap_write_unwritten(
563 xfs_inode_t *ip,
564 xfs_off_t offset,
565 xfs_off_t count,
566 bool update_isize)
567 {
568 xfs_mount_t *mp = ip->i_mount;
569 xfs_fileoff_t offset_fsb;
570 xfs_filblks_t count_fsb;
571 xfs_filblks_t numblks_fsb;
572 int nimaps;
573 xfs_trans_t *tp;
574 xfs_bmbt_irec_t imap;
575 struct inode *inode = VFS_I(ip);
576 xfs_fsize_t i_size;
577 uint resblks;
578 int error;
579
580 trace_xfs_unwritten_convert(ip, offset, count);
581
582 offset_fsb = XFS_B_TO_FSBT(mp, offset);
583 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
584 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
585
586 /*
587 * Reserve enough blocks in this transaction for two complete extent
588 * btree splits. We may be converting the middle part of an unwritten
589 * extent and in this case we will insert two new extents in the btree
590 * each of which could cause a full split.
591 *
592 * This reservation amount will be used in the first call to
593 * xfs_bmbt_split() to select an AG with enough space to satisfy the
594 * rest of the operation.
595 */
596 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
597
598 /* Attach dquots so that bmbt splits are accounted correctly. */
599 error = xfs_qm_dqattach(ip);
600 if (error)
601 return error;
602
603 do {
604 /*
605 * Set up a transaction to convert the range of extents
606 * from unwritten to real. Do allocations in a loop until
607 * we have covered the range passed in.
608 *
609 * Note that we can't risk to recursing back into the filesystem
610 * here as we might be asked to write out the same inode that we
611 * complete here and might deadlock on the iolock.
612 */
613 error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, resblks,
614 0, true, &tp);
615 if (error)
616 return error;
617
618 error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
619 XFS_IEXT_WRITE_UNWRITTEN_CNT);
620 if (error)
621 goto error_on_bmapi_transaction;
622
623 /*
624 * Modify the unwritten extent state of the buffer.
625 */
626 nimaps = 1;
627 error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb,
628 XFS_BMAPI_CONVERT, resblks, &imap,
629 &nimaps);
630 if (error)
631 goto error_on_bmapi_transaction;
632
633 /*
634 * Log the updated inode size as we go. We have to be careful
635 * to only log it up to the actual write offset if it is
636 * halfway into a block.
637 */
638 i_size = XFS_FSB_TO_B(mp, offset_fsb + count_fsb);
639 if (i_size > offset + count)
640 i_size = offset + count;
641 if (update_isize && i_size > i_size_read(inode))
642 i_size_write(inode, i_size);
643 i_size = xfs_new_eof(ip, i_size);
644 if (i_size) {
645 ip->i_disk_size = i_size;
646 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
647 }
648
649 error = xfs_trans_commit(tp);
650 xfs_iunlock(ip, XFS_ILOCK_EXCL);
651 if (error)
652 return error;
653
654 if (unlikely(!xfs_valid_startblock(ip, imap.br_startblock))) {
655 xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
656 return xfs_alert_fsblock_zero(ip, &imap);
657 }
658
659 if ((numblks_fsb = imap.br_blockcount) == 0) {
660 /*
661 * The numblks_fsb value should always get
662 * smaller, otherwise the loop is stuck.
663 */
664 ASSERT(imap.br_blockcount);
665 break;
666 }
667 offset_fsb += numblks_fsb;
668 count_fsb -= numblks_fsb;
669 } while (count_fsb > 0);
670
671 return 0;
672
673 error_on_bmapi_transaction:
674 xfs_trans_cancel(tp);
675 xfs_iunlock(ip, XFS_ILOCK_EXCL);
676 return error;
677 }
678
679 static inline bool
imap_needs_alloc(struct inode * inode,unsigned flags,struct xfs_bmbt_irec * imap,int nimaps)680 imap_needs_alloc(
681 struct inode *inode,
682 unsigned flags,
683 struct xfs_bmbt_irec *imap,
684 int nimaps)
685 {
686 /* don't allocate blocks when just zeroing */
687 if (flags & IOMAP_ZERO)
688 return false;
689 if (!nimaps ||
690 imap->br_startblock == HOLESTARTBLOCK ||
691 imap->br_startblock == DELAYSTARTBLOCK)
692 return true;
693 /* we convert unwritten extents before copying the data for DAX */
694 if ((flags & IOMAP_DAX) && imap->br_state == XFS_EXT_UNWRITTEN)
695 return true;
696 return false;
697 }
698
699 static inline bool
imap_needs_cow(struct xfs_inode * ip,unsigned int flags,struct xfs_bmbt_irec * imap,int nimaps)700 imap_needs_cow(
701 struct xfs_inode *ip,
702 unsigned int flags,
703 struct xfs_bmbt_irec *imap,
704 int nimaps)
705 {
706 if (!xfs_is_cow_inode(ip))
707 return false;
708
709 /* when zeroing we don't have to COW holes or unwritten extents */
710 if (flags & IOMAP_ZERO) {
711 if (!nimaps ||
712 imap->br_startblock == HOLESTARTBLOCK ||
713 imap->br_state == XFS_EXT_UNWRITTEN)
714 return false;
715 }
716
717 return true;
718 }
719
720 static int
xfs_ilock_for_iomap(struct xfs_inode * ip,unsigned flags,unsigned * lockmode)721 xfs_ilock_for_iomap(
722 struct xfs_inode *ip,
723 unsigned flags,
724 unsigned *lockmode)
725 {
726 unsigned int mode = *lockmode;
727 bool is_write = flags & (IOMAP_WRITE | IOMAP_ZERO);
728
729 /*
730 * COW writes may allocate delalloc space or convert unwritten COW
731 * extents, so we need to make sure to take the lock exclusively here.
732 */
733 if (xfs_is_cow_inode(ip) && is_write)
734 mode = XFS_ILOCK_EXCL;
735
736 /*
737 * Extents not yet cached requires exclusive access, don't block. This
738 * is an opencoded xfs_ilock_data_map_shared() call but with
739 * non-blocking behaviour.
740 */
741 if (xfs_need_iread_extents(&ip->i_df)) {
742 if (flags & IOMAP_NOWAIT)
743 return -EAGAIN;
744 mode = XFS_ILOCK_EXCL;
745 }
746
747 relock:
748 if (flags & IOMAP_NOWAIT) {
749 if (!xfs_ilock_nowait(ip, mode))
750 return -EAGAIN;
751 } else {
752 xfs_ilock(ip, mode);
753 }
754
755 /*
756 * The reflink iflag could have changed since the earlier unlocked
757 * check, so if we got ILOCK_SHARED for a write and but we're now a
758 * reflink inode we have to switch to ILOCK_EXCL and relock.
759 */
760 if (mode == XFS_ILOCK_SHARED && is_write && xfs_is_cow_inode(ip)) {
761 xfs_iunlock(ip, mode);
762 mode = XFS_ILOCK_EXCL;
763 goto relock;
764 }
765
766 *lockmode = mode;
767 return 0;
768 }
769
770 /*
771 * Check that the imap we are going to return to the caller spans the entire
772 * range that the caller requested for the IO.
773 */
774 static bool
imap_spans_range(struct xfs_bmbt_irec * imap,xfs_fileoff_t offset_fsb,xfs_fileoff_t end_fsb)775 imap_spans_range(
776 struct xfs_bmbt_irec *imap,
777 xfs_fileoff_t offset_fsb,
778 xfs_fileoff_t end_fsb)
779 {
780 if (imap->br_startoff > offset_fsb)
781 return false;
782 if (imap->br_startoff + imap->br_blockcount < end_fsb)
783 return false;
784 return true;
785 }
786
787 static int
xfs_direct_write_iomap_begin(struct inode * inode,loff_t offset,loff_t length,unsigned flags,struct iomap * iomap,struct iomap * srcmap)788 xfs_direct_write_iomap_begin(
789 struct inode *inode,
790 loff_t offset,
791 loff_t length,
792 unsigned flags,
793 struct iomap *iomap,
794 struct iomap *srcmap)
795 {
796 struct xfs_inode *ip = XFS_I(inode);
797 struct xfs_mount *mp = ip->i_mount;
798 struct xfs_bmbt_irec imap, cmap;
799 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
800 xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length);
801 int nimaps = 1, error = 0;
802 bool shared = false;
803 u16 iomap_flags = 0;
804 unsigned int lockmode = XFS_ILOCK_SHARED;
805 u64 seq;
806
807 ASSERT(flags & (IOMAP_WRITE | IOMAP_ZERO));
808
809 if (xfs_is_shutdown(mp))
810 return -EIO;
811
812 /*
813 * Writes that span EOF might trigger an IO size update on completion,
814 * so consider them to be dirty for the purposes of O_DSYNC even if
815 * there is no other metadata changes pending or have been made here.
816 */
817 if (offset + length > i_size_read(inode))
818 iomap_flags |= IOMAP_F_DIRTY;
819
820 error = xfs_ilock_for_iomap(ip, flags, &lockmode);
821 if (error)
822 return error;
823
824 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
825 &nimaps, 0);
826 if (error)
827 goto out_unlock;
828
829 if (imap_needs_cow(ip, flags, &imap, nimaps)) {
830 error = -EAGAIN;
831 if (flags & IOMAP_NOWAIT)
832 goto out_unlock;
833
834 /* may drop and re-acquire the ilock */
835 error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared,
836 &lockmode,
837 (flags & IOMAP_DIRECT) || IS_DAX(inode));
838 if (error)
839 goto out_unlock;
840 if (shared)
841 goto out_found_cow;
842 end_fsb = imap.br_startoff + imap.br_blockcount;
843 length = XFS_FSB_TO_B(mp, end_fsb) - offset;
844 }
845
846 if (imap_needs_alloc(inode, flags, &imap, nimaps))
847 goto allocate_blocks;
848
849 /*
850 * NOWAIT and OVERWRITE I/O needs to span the entire requested I/O with
851 * a single map so that we avoid partial IO failures due to the rest of
852 * the I/O range not covered by this map triggering an EAGAIN condition
853 * when it is subsequently mapped and aborting the I/O.
854 */
855 if (flags & (IOMAP_NOWAIT | IOMAP_OVERWRITE_ONLY)) {
856 error = -EAGAIN;
857 if (!imap_spans_range(&imap, offset_fsb, end_fsb))
858 goto out_unlock;
859 }
860
861 /*
862 * For overwrite only I/O, we cannot convert unwritten extents without
863 * requiring sub-block zeroing. This can only be done under an
864 * exclusive IOLOCK, hence return -EAGAIN if this is not a written
865 * extent to tell the caller to try again.
866 */
867 if (flags & IOMAP_OVERWRITE_ONLY) {
868 error = -EAGAIN;
869 if (imap.br_state != XFS_EXT_NORM &&
870 ((offset | length) & mp->m_blockmask))
871 goto out_unlock;
872 }
873
874 seq = xfs_iomap_inode_sequence(ip, iomap_flags);
875 xfs_iunlock(ip, lockmode);
876 trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);
877 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, iomap_flags, seq);
878
879 allocate_blocks:
880 error = -EAGAIN;
881 if (flags & (IOMAP_NOWAIT | IOMAP_OVERWRITE_ONLY))
882 goto out_unlock;
883
884 /*
885 * We cap the maximum length we map to a sane size to keep the chunks
886 * of work done where somewhat symmetric with the work writeback does.
887 * This is a completely arbitrary number pulled out of thin air as a
888 * best guess for initial testing.
889 *
890 * Note that the values needs to be less than 32-bits wide until the
891 * lower level functions are updated.
892 */
893 length = min_t(loff_t, length, 1024 * PAGE_SIZE);
894 end_fsb = xfs_iomap_end_fsb(mp, offset, length);
895
896 if (offset + length > XFS_ISIZE(ip))
897 end_fsb = xfs_iomap_eof_align_last_fsb(ip, end_fsb);
898 else if (nimaps && imap.br_startblock == HOLESTARTBLOCK)
899 end_fsb = min(end_fsb, imap.br_startoff + imap.br_blockcount);
900 xfs_iunlock(ip, lockmode);
901
902 error = xfs_iomap_write_direct(ip, offset_fsb, end_fsb - offset_fsb,
903 flags, &imap, &seq);
904 if (error)
905 return error;
906
907 trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap);
908 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags,
909 iomap_flags | IOMAP_F_NEW, seq);
910
911 out_found_cow:
912 length = XFS_FSB_TO_B(mp, cmap.br_startoff + cmap.br_blockcount);
913 trace_xfs_iomap_found(ip, offset, length - offset, XFS_COW_FORK, &cmap);
914 if (imap.br_startblock != HOLESTARTBLOCK) {
915 seq = xfs_iomap_inode_sequence(ip, 0);
916 error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, seq);
917 if (error)
918 goto out_unlock;
919 }
920 seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);
921 xfs_iunlock(ip, lockmode);
922 return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, IOMAP_F_SHARED, seq);
923
924 out_unlock:
925 if (lockmode)
926 xfs_iunlock(ip, lockmode);
927 return error;
928 }
929
930 const struct iomap_ops xfs_direct_write_iomap_ops = {
931 .iomap_begin = xfs_direct_write_iomap_begin,
932 };
933
934 static int
xfs_dax_write_iomap_end(struct inode * inode,loff_t pos,loff_t length,ssize_t written,unsigned flags,struct iomap * iomap)935 xfs_dax_write_iomap_end(
936 struct inode *inode,
937 loff_t pos,
938 loff_t length,
939 ssize_t written,
940 unsigned flags,
941 struct iomap *iomap)
942 {
943 struct xfs_inode *ip = XFS_I(inode);
944
945 if (!xfs_is_cow_inode(ip))
946 return 0;
947
948 if (!written) {
949 xfs_reflink_cancel_cow_range(ip, pos, length, true);
950 return 0;
951 }
952
953 return xfs_reflink_end_cow(ip, pos, written);
954 }
955
956 const struct iomap_ops xfs_dax_write_iomap_ops = {
957 .iomap_begin = xfs_direct_write_iomap_begin,
958 .iomap_end = xfs_dax_write_iomap_end,
959 };
960
961 static int
xfs_buffered_write_iomap_begin(struct inode * inode,loff_t offset,loff_t count,unsigned flags,struct iomap * iomap,struct iomap * srcmap)962 xfs_buffered_write_iomap_begin(
963 struct inode *inode,
964 loff_t offset,
965 loff_t count,
966 unsigned flags,
967 struct iomap *iomap,
968 struct iomap *srcmap)
969 {
970 struct xfs_inode *ip = XFS_I(inode);
971 struct xfs_mount *mp = ip->i_mount;
972 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
973 xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, count);
974 struct xfs_bmbt_irec imap, cmap;
975 struct xfs_iext_cursor icur, ccur;
976 xfs_fsblock_t prealloc_blocks = 0;
977 bool eof = false, cow_eof = false, shared = false;
978 int allocfork = XFS_DATA_FORK;
979 int error = 0;
980 unsigned int lockmode = XFS_ILOCK_EXCL;
981 u64 seq;
982
983 if (xfs_is_shutdown(mp))
984 return -EIO;
985
986 /* we can't use delayed allocations when using extent size hints */
987 if (xfs_get_extsz_hint(ip))
988 return xfs_direct_write_iomap_begin(inode, offset, count,
989 flags, iomap, srcmap);
990
991 error = xfs_qm_dqattach(ip);
992 if (error)
993 return error;
994
995 error = xfs_ilock_for_iomap(ip, flags, &lockmode);
996 if (error)
997 return error;
998
999 if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(&ip->i_df)) ||
1000 XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
1001 xfs_bmap_mark_sick(ip, XFS_DATA_FORK);
1002 error = -EFSCORRUPTED;
1003 goto out_unlock;
1004 }
1005
1006 XFS_STATS_INC(mp, xs_blk_mapw);
1007
1008 error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
1009 if (error)
1010 goto out_unlock;
1011
1012 /*
1013 * Search the data fork first to look up our source mapping. We
1014 * always need the data fork map, as we have to return it to the
1015 * iomap code so that the higher level write code can read data in to
1016 * perform read-modify-write cycles for unaligned writes.
1017 */
1018 eof = !xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap);
1019 if (eof)
1020 imap.br_startoff = end_fsb; /* fake hole until the end */
1021
1022 /* We never need to allocate blocks for zeroing or unsharing a hole. */
1023 if ((flags & (IOMAP_UNSHARE | IOMAP_ZERO)) &&
1024 imap.br_startoff > offset_fsb) {
1025 xfs_hole_to_iomap(ip, iomap, offset_fsb, imap.br_startoff);
1026 goto out_unlock;
1027 }
1028
1029 /*
1030 * For zeroing, trim a delalloc extent that extends beyond the EOF
1031 * block. If it starts beyond the EOF block, convert it to an
1032 * unwritten extent.
1033 */
1034 if ((flags & IOMAP_ZERO) && imap.br_startoff <= offset_fsb &&
1035 isnullstartblock(imap.br_startblock)) {
1036 xfs_fileoff_t eof_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
1037
1038 if (offset_fsb >= eof_fsb)
1039 goto convert_delay;
1040 if (end_fsb > eof_fsb) {
1041 end_fsb = eof_fsb;
1042 xfs_trim_extent(&imap, offset_fsb,
1043 end_fsb - offset_fsb);
1044 }
1045 }
1046
1047 /*
1048 * Search the COW fork extent list even if we did not find a data fork
1049 * extent. This serves two purposes: first this implements the
1050 * speculative preallocation using cowextsize, so that we also unshare
1051 * block adjacent to shared blocks instead of just the shared blocks
1052 * themselves. Second the lookup in the extent list is generally faster
1053 * than going out to the shared extent tree.
1054 */
1055 if (xfs_is_cow_inode(ip)) {
1056 if (!ip->i_cowfp) {
1057 ASSERT(!xfs_is_reflink_inode(ip));
1058 xfs_ifork_init_cow(ip);
1059 }
1060 cow_eof = !xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb,
1061 &ccur, &cmap);
1062 if (!cow_eof && cmap.br_startoff <= offset_fsb) {
1063 trace_xfs_reflink_cow_found(ip, &cmap);
1064 goto found_cow;
1065 }
1066 }
1067
1068 if (imap.br_startoff <= offset_fsb) {
1069 /*
1070 * For reflink files we may need a delalloc reservation when
1071 * overwriting shared extents. This includes zeroing of
1072 * existing extents that contain data.
1073 */
1074 if (!xfs_is_cow_inode(ip) ||
1075 ((flags & IOMAP_ZERO) && imap.br_state != XFS_EXT_NORM)) {
1076 trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
1077 &imap);
1078 goto found_imap;
1079 }
1080
1081 xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);
1082
1083 /* Trim the mapping to the nearest shared extent boundary. */
1084 error = xfs_bmap_trim_cow(ip, &imap, &shared);
1085 if (error)
1086 goto out_unlock;
1087
1088 /* Not shared? Just report the (potentially capped) extent. */
1089 if (!shared) {
1090 trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
1091 &imap);
1092 goto found_imap;
1093 }
1094
1095 /*
1096 * Fork all the shared blocks from our write offset until the
1097 * end of the extent.
1098 */
1099 allocfork = XFS_COW_FORK;
1100 end_fsb = imap.br_startoff + imap.br_blockcount;
1101 } else {
1102 /*
1103 * We cap the maximum length we map here to MAX_WRITEBACK_PAGES
1104 * pages to keep the chunks of work done where somewhat
1105 * symmetric with the work writeback does. This is a completely
1106 * arbitrary number pulled out of thin air.
1107 *
1108 * Note that the values needs to be less than 32-bits wide until
1109 * the lower level functions are updated.
1110 */
1111 count = min_t(loff_t, count, 1024 * PAGE_SIZE);
1112 end_fsb = xfs_iomap_end_fsb(mp, offset, count);
1113
1114 if (xfs_is_always_cow_inode(ip))
1115 allocfork = XFS_COW_FORK;
1116 }
1117
1118 if (eof && offset + count > XFS_ISIZE(ip)) {
1119 /*
1120 * Determine the initial size of the preallocation.
1121 * We clean up any extra preallocation when the file is closed.
1122 */
1123 if (xfs_has_allocsize(mp))
1124 prealloc_blocks = mp->m_allocsize_blocks;
1125 else if (allocfork == XFS_DATA_FORK)
1126 prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork,
1127 offset, count, &icur);
1128 else
1129 prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork,
1130 offset, count, &ccur);
1131 if (prealloc_blocks) {
1132 xfs_extlen_t align;
1133 xfs_off_t end_offset;
1134 xfs_fileoff_t p_end_fsb;
1135
1136 end_offset = XFS_ALLOC_ALIGN(mp, offset + count - 1);
1137 p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) +
1138 prealloc_blocks;
1139
1140 align = xfs_eof_alignment(ip);
1141 if (align)
1142 p_end_fsb = roundup_64(p_end_fsb, align);
1143
1144 p_end_fsb = min(p_end_fsb,
1145 XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
1146 ASSERT(p_end_fsb > offset_fsb);
1147 prealloc_blocks = p_end_fsb - end_fsb;
1148 }
1149 }
1150
1151 retry:
1152 error = xfs_bmapi_reserve_delalloc(ip, allocfork, offset_fsb,
1153 end_fsb - offset_fsb, prealloc_blocks,
1154 allocfork == XFS_DATA_FORK ? &imap : &cmap,
1155 allocfork == XFS_DATA_FORK ? &icur : &ccur,
1156 allocfork == XFS_DATA_FORK ? eof : cow_eof);
1157 switch (error) {
1158 case 0:
1159 break;
1160 case -ENOSPC:
1161 case -EDQUOT:
1162 /* retry without any preallocation */
1163 trace_xfs_delalloc_enospc(ip, offset, count);
1164 if (prealloc_blocks) {
1165 prealloc_blocks = 0;
1166 goto retry;
1167 }
1168 fallthrough;
1169 default:
1170 goto out_unlock;
1171 }
1172
1173 if (allocfork == XFS_COW_FORK) {
1174 trace_xfs_iomap_alloc(ip, offset, count, allocfork, &cmap);
1175 goto found_cow;
1176 }
1177
1178 /*
1179 * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
1180 * them out if the write happens to fail.
1181 */
1182 seq = xfs_iomap_inode_sequence(ip, IOMAP_F_NEW);
1183 xfs_iunlock(ip, lockmode);
1184 trace_xfs_iomap_alloc(ip, offset, count, allocfork, &imap);
1185 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, IOMAP_F_NEW, seq);
1186
1187 found_imap:
1188 seq = xfs_iomap_inode_sequence(ip, 0);
1189 xfs_iunlock(ip, lockmode);
1190 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, 0, seq);
1191
1192 convert_delay:
1193 xfs_iunlock(ip, lockmode);
1194 truncate_pagecache(inode, offset);
1195 error = xfs_bmapi_convert_delalloc(ip, XFS_DATA_FORK, offset,
1196 iomap, NULL);
1197 if (error)
1198 return error;
1199
1200 trace_xfs_iomap_alloc(ip, offset, count, XFS_DATA_FORK, &imap);
1201 return 0;
1202
1203 found_cow:
1204 seq = xfs_iomap_inode_sequence(ip, 0);
1205 if (imap.br_startoff <= offset_fsb) {
1206 error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, seq);
1207 if (error)
1208 goto out_unlock;
1209 seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);
1210 xfs_iunlock(ip, lockmode);
1211 return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags,
1212 IOMAP_F_SHARED, seq);
1213 }
1214
1215 xfs_trim_extent(&cmap, offset_fsb, imap.br_startoff - offset_fsb);
1216 xfs_iunlock(ip, lockmode);
1217 return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, 0, seq);
1218
1219 out_unlock:
1220 xfs_iunlock(ip, lockmode);
1221 return error;
1222 }
1223
1224 static int
xfs_buffered_write_delalloc_punch(struct inode * inode,loff_t offset,loff_t length)1225 xfs_buffered_write_delalloc_punch(
1226 struct inode *inode,
1227 loff_t offset,
1228 loff_t length)
1229 {
1230 xfs_bmap_punch_delalloc_range(XFS_I(inode), offset, offset + length);
1231 return 0;
1232 }
1233
1234 static int
xfs_buffered_write_iomap_end(struct inode * inode,loff_t offset,loff_t length,ssize_t written,unsigned flags,struct iomap * iomap)1235 xfs_buffered_write_iomap_end(
1236 struct inode *inode,
1237 loff_t offset,
1238 loff_t length,
1239 ssize_t written,
1240 unsigned flags,
1241 struct iomap *iomap)
1242 {
1243
1244 struct xfs_mount *mp = XFS_M(inode->i_sb);
1245 int error;
1246
1247 error = iomap_file_buffered_write_punch_delalloc(inode, iomap, offset,
1248 length, written, &xfs_buffered_write_delalloc_punch);
1249 if (error && !xfs_is_shutdown(mp)) {
1250 xfs_alert(mp, "%s: unable to clean up ino 0x%llx",
1251 __func__, XFS_I(inode)->i_ino);
1252 return error;
1253 }
1254 return 0;
1255 }
1256
1257 const struct iomap_ops xfs_buffered_write_iomap_ops = {
1258 .iomap_begin = xfs_buffered_write_iomap_begin,
1259 .iomap_end = xfs_buffered_write_iomap_end,
1260 };
1261
1262 /*
1263 * iomap_page_mkwrite() will never fail in a way that requires delalloc extents
1264 * that it allocated to be revoked. Hence we do not need an .iomap_end method
1265 * for this operation.
1266 */
1267 const struct iomap_ops xfs_page_mkwrite_iomap_ops = {
1268 .iomap_begin = xfs_buffered_write_iomap_begin,
1269 };
1270
1271 static int
xfs_read_iomap_begin(struct inode * inode,loff_t offset,loff_t length,unsigned flags,struct iomap * iomap,struct iomap * srcmap)1272 xfs_read_iomap_begin(
1273 struct inode *inode,
1274 loff_t offset,
1275 loff_t length,
1276 unsigned flags,
1277 struct iomap *iomap,
1278 struct iomap *srcmap)
1279 {
1280 struct xfs_inode *ip = XFS_I(inode);
1281 struct xfs_mount *mp = ip->i_mount;
1282 struct xfs_bmbt_irec imap;
1283 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
1284 xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length);
1285 int nimaps = 1, error = 0;
1286 bool shared = false;
1287 unsigned int lockmode = XFS_ILOCK_SHARED;
1288 u64 seq;
1289
1290 ASSERT(!(flags & (IOMAP_WRITE | IOMAP_ZERO)));
1291
1292 if (xfs_is_shutdown(mp))
1293 return -EIO;
1294
1295 error = xfs_ilock_for_iomap(ip, flags, &lockmode);
1296 if (error)
1297 return error;
1298 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
1299 &nimaps, 0);
1300 if (!error && ((flags & IOMAP_REPORT) || IS_DAX(inode)))
1301 error = xfs_reflink_trim_around_shared(ip, &imap, &shared);
1302 seq = xfs_iomap_inode_sequence(ip, shared ? IOMAP_F_SHARED : 0);
1303 xfs_iunlock(ip, lockmode);
1304
1305 if (error)
1306 return error;
1307 trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);
1308 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags,
1309 shared ? IOMAP_F_SHARED : 0, seq);
1310 }
1311
1312 const struct iomap_ops xfs_read_iomap_ops = {
1313 .iomap_begin = xfs_read_iomap_begin,
1314 };
1315
1316 static int
xfs_seek_iomap_begin(struct inode * inode,loff_t offset,loff_t length,unsigned flags,struct iomap * iomap,struct iomap * srcmap)1317 xfs_seek_iomap_begin(
1318 struct inode *inode,
1319 loff_t offset,
1320 loff_t length,
1321 unsigned flags,
1322 struct iomap *iomap,
1323 struct iomap *srcmap)
1324 {
1325 struct xfs_inode *ip = XFS_I(inode);
1326 struct xfs_mount *mp = ip->i_mount;
1327 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
1328 xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + length);
1329 xfs_fileoff_t cow_fsb = NULLFILEOFF, data_fsb = NULLFILEOFF;
1330 struct xfs_iext_cursor icur;
1331 struct xfs_bmbt_irec imap, cmap;
1332 int error = 0;
1333 unsigned lockmode;
1334 u64 seq;
1335
1336 if (xfs_is_shutdown(mp))
1337 return -EIO;
1338
1339 lockmode = xfs_ilock_data_map_shared(ip);
1340 error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
1341 if (error)
1342 goto out_unlock;
1343
1344 if (xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap)) {
1345 /*
1346 * If we found a data extent we are done.
1347 */
1348 if (imap.br_startoff <= offset_fsb)
1349 goto done;
1350 data_fsb = imap.br_startoff;
1351 } else {
1352 /*
1353 * Fake a hole until the end of the file.
1354 */
1355 data_fsb = xfs_iomap_end_fsb(mp, offset, length);
1356 }
1357
1358 /*
1359 * If a COW fork extent covers the hole, report it - capped to the next
1360 * data fork extent:
1361 */
1362 if (xfs_inode_has_cow_data(ip) &&
1363 xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap))
1364 cow_fsb = cmap.br_startoff;
1365 if (cow_fsb != NULLFILEOFF && cow_fsb <= offset_fsb) {
1366 if (data_fsb < cow_fsb + cmap.br_blockcount)
1367 end_fsb = min(end_fsb, data_fsb);
1368 xfs_trim_extent(&cmap, offset_fsb, end_fsb - offset_fsb);
1369 seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);
1370 error = xfs_bmbt_to_iomap(ip, iomap, &cmap, flags,
1371 IOMAP_F_SHARED, seq);
1372 /*
1373 * This is a COW extent, so we must probe the page cache
1374 * because there could be dirty page cache being backed
1375 * by this extent.
1376 */
1377 iomap->type = IOMAP_UNWRITTEN;
1378 goto out_unlock;
1379 }
1380
1381 /*
1382 * Else report a hole, capped to the next found data or COW extent.
1383 */
1384 if (cow_fsb != NULLFILEOFF && cow_fsb < data_fsb)
1385 imap.br_blockcount = cow_fsb - offset_fsb;
1386 else
1387 imap.br_blockcount = data_fsb - offset_fsb;
1388 imap.br_startoff = offset_fsb;
1389 imap.br_startblock = HOLESTARTBLOCK;
1390 imap.br_state = XFS_EXT_NORM;
1391 done:
1392 seq = xfs_iomap_inode_sequence(ip, 0);
1393 xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);
1394 error = xfs_bmbt_to_iomap(ip, iomap, &imap, flags, 0, seq);
1395 out_unlock:
1396 xfs_iunlock(ip, lockmode);
1397 return error;
1398 }
1399
1400 const struct iomap_ops xfs_seek_iomap_ops = {
1401 .iomap_begin = xfs_seek_iomap_begin,
1402 };
1403
1404 static int
xfs_xattr_iomap_begin(struct inode * inode,loff_t offset,loff_t length,unsigned flags,struct iomap * iomap,struct iomap * srcmap)1405 xfs_xattr_iomap_begin(
1406 struct inode *inode,
1407 loff_t offset,
1408 loff_t length,
1409 unsigned flags,
1410 struct iomap *iomap,
1411 struct iomap *srcmap)
1412 {
1413 struct xfs_inode *ip = XFS_I(inode);
1414 struct xfs_mount *mp = ip->i_mount;
1415 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
1416 xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + length);
1417 struct xfs_bmbt_irec imap;
1418 int nimaps = 1, error = 0;
1419 unsigned lockmode;
1420 int seq;
1421
1422 if (xfs_is_shutdown(mp))
1423 return -EIO;
1424
1425 lockmode = xfs_ilock_attr_map_shared(ip);
1426
1427 /* if there are no attribute fork or extents, return ENOENT */
1428 if (!xfs_inode_has_attr_fork(ip) || !ip->i_af.if_nextents) {
1429 error = -ENOENT;
1430 goto out_unlock;
1431 }
1432
1433 ASSERT(ip->i_af.if_format != XFS_DINODE_FMT_LOCAL);
1434 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
1435 &nimaps, XFS_BMAPI_ATTRFORK);
1436 out_unlock:
1437
1438 seq = xfs_iomap_inode_sequence(ip, IOMAP_F_XATTR);
1439 xfs_iunlock(ip, lockmode);
1440
1441 if (error)
1442 return error;
1443 ASSERT(nimaps);
1444 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, IOMAP_F_XATTR, seq);
1445 }
1446
1447 const struct iomap_ops xfs_xattr_iomap_ops = {
1448 .iomap_begin = xfs_xattr_iomap_begin,
1449 };
1450
1451 int
xfs_zero_range(struct xfs_inode * ip,loff_t pos,loff_t len,bool * did_zero)1452 xfs_zero_range(
1453 struct xfs_inode *ip,
1454 loff_t pos,
1455 loff_t len,
1456 bool *did_zero)
1457 {
1458 struct inode *inode = VFS_I(ip);
1459
1460 if (IS_DAX(inode))
1461 return dax_zero_range(inode, pos, len, did_zero,
1462 &xfs_dax_write_iomap_ops);
1463 return iomap_zero_range(inode, pos, len, did_zero,
1464 &xfs_buffered_write_iomap_ops);
1465 }
1466
1467 int
xfs_truncate_page(struct xfs_inode * ip,loff_t pos,bool * did_zero)1468 xfs_truncate_page(
1469 struct xfs_inode *ip,
1470 loff_t pos,
1471 bool *did_zero)
1472 {
1473 struct inode *inode = VFS_I(ip);
1474
1475 if (IS_DAX(inode))
1476 return dax_truncate_page(inode, pos, did_zero,
1477 &xfs_dax_write_iomap_ops);
1478 return iomap_truncate_page(inode, pos, did_zero,
1479 &xfs_buffered_write_iomap_ops);
1480 }
1481