1484 lines · c
1// SPDX-License-Identifier: GPL-2.02/*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 36static int37xfs_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 54u6455xfs_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 and70 * length.71 */72static bool73xfs_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 89static const struct iomap_folio_ops xfs_iomap_folio_ops = {90 .iomap_valid = xfs_iomap_valid,91};92 93int94xfs_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 else125 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 else133 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 145static void146xfs_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 162static inline xfs_fileoff_t163xfs_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 173static xfs_extlen_t174xfs_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 unit183 * (m_dalign) boundary if the file size is >= stripe unit184 * size, and we are allocating past the allocation eof.185 *186 * If mounted with the "-o swalloc" option the alignment is187 * 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 next203 * stripe unit boundary.204 */205xfs_fileoff_t206xfs_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 else225 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 240int241xfs_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 zero277 * the block before we commit the transaction. Ideally we'd like to do278 * this outside the transaction context, but if we commit and then crash279 * we may not have zeroed the blocks and this will be exposed on280 * recovery of the allocation. Hence we must zero before commit.281 *282 * Further, if we are mapping unwritten extents here, we need to zero283 * and convert them to written so that we don't need an unwritten extent284 * callback for DAX. This also means that we need to be able to dip into285 * the reserve block pool for bmbt block allocation if there is no space286 * 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 the308 * 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 transaction318 */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 328out_unlock:329 *seq = xfs_iomap_inode_sequence(ip, 0);330 xfs_iunlock(ip, XFS_ILOCK_EXCL);331 return error;332 333out_trans_cancel:334 xfs_trans_cancel(tp);335 goto out_unlock;336}337 338STATIC bool339xfs_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 360STATIC void361xfs_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 398static int64_t399xfs_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 increase423 * the preallocation size as the size of the file grows. Cap the maximum size424 * at a single extent or less if the filesystem is near full. The closer the425 * filesystem is to being full, the smaller the maximum preallocation.426 */427STATIC xfs_fsblock_t428xfs_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 is449 * smaller than the minimum preallocation and we are using the default450 * dynamic preallocation scheme, as it is likely this is the only write451 * 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 are458 * 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 the467 * preallocation size. Note that we don't care if the previous extents468 * 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 extent483 * length, then use the current offset as the basis. This ensures that484 * for large files the preallocation size always extends to485 * XFS_BMBT_MAX_EXTLEN rather than falling short due to things like stripe486 * 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 prealloc495 * down to the nearest power of two value after throttling. To prevent496 * the round down from unconditionally reducing the maximum supported497 * prealloc size, we round up first, apply appropriate throttling, round498 * 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 else508 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 to513 * 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 available527 * in each of the quotas and the overall filesystem.528 *529 * The shift throttle value is set to the maximum value as determined by530 * 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 in539 * 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 is548 * available, squash the prealloc hard. This can happen if we549 * have a large file on a small filesystem and the above550 * 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 561int562xfs_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 extent588 * btree splits. We may be converting the middle part of an unwritten589 * extent and in this case we will insert two new extents in the btree590 * each of which could cause a full split.591 *592 * This reservation amount will be used in the first call to593 * xfs_bmbt_split() to select an AG with enough space to satisfy the594 * 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 extents606 * from unwritten to real. Do allocations in a loop until607 * we have covered the range passed in.608 *609 * Note that we can't risk to recursing back into the filesystem610 * here as we might be asked to write out the same inode that we611 * 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 careful635 * to only log it up to the actual write offset if it is636 * 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 get662 * 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 673error_on_bmapi_transaction:674 xfs_trans_cancel(tp);675 xfs_iunlock(ip, XFS_ILOCK_EXCL);676 return error;677}678 679static inline bool680imap_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 699static inline bool700imap_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_UNSHARE | 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/*721 * Extents not yet cached requires exclusive access, don't block for722 * IOMAP_NOWAIT.723 *724 * This is basically an opencoded xfs_ilock_data_map_shared() call, but with725 * support for IOMAP_NOWAIT.726 */727static int728xfs_ilock_for_iomap(729 struct xfs_inode *ip,730 unsigned flags,731 unsigned *lockmode)732{733 if (flags & IOMAP_NOWAIT) {734 if (xfs_need_iread_extents(&ip->i_df))735 return -EAGAIN;736 if (!xfs_ilock_nowait(ip, *lockmode))737 return -EAGAIN;738 } else {739 if (xfs_need_iread_extents(&ip->i_df))740 *lockmode = XFS_ILOCK_EXCL;741 xfs_ilock(ip, *lockmode);742 }743 744 return 0;745}746 747/*748 * Check that the imap we are going to return to the caller spans the entire749 * range that the caller requested for the IO.750 */751static bool752imap_spans_range(753 struct xfs_bmbt_irec *imap,754 xfs_fileoff_t offset_fsb,755 xfs_fileoff_t end_fsb)756{757 if (imap->br_startoff > offset_fsb)758 return false;759 if (imap->br_startoff + imap->br_blockcount < end_fsb)760 return false;761 return true;762}763 764static int765xfs_direct_write_iomap_begin(766 struct inode *inode,767 loff_t offset,768 loff_t length,769 unsigned flags,770 struct iomap *iomap,771 struct iomap *srcmap)772{773 struct xfs_inode *ip = XFS_I(inode);774 struct xfs_mount *mp = ip->i_mount;775 struct xfs_bmbt_irec imap, cmap;776 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);777 xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length);778 int nimaps = 1, error = 0;779 bool shared = false;780 u16 iomap_flags = 0;781 unsigned int lockmode;782 u64 seq;783 784 ASSERT(flags & (IOMAP_WRITE | IOMAP_ZERO));785 786 if (xfs_is_shutdown(mp))787 return -EIO;788 789 /*790 * Writes that span EOF might trigger an IO size update on completion,791 * so consider them to be dirty for the purposes of O_DSYNC even if792 * there is no other metadata changes pending or have been made here.793 */794 if (offset + length > i_size_read(inode))795 iomap_flags |= IOMAP_F_DIRTY;796 797 /*798 * COW writes may allocate delalloc space or convert unwritten COW799 * extents, so we need to make sure to take the lock exclusively here.800 */801 if (xfs_is_cow_inode(ip))802 lockmode = XFS_ILOCK_EXCL;803 else804 lockmode = XFS_ILOCK_SHARED;805 806relock:807 error = xfs_ilock_for_iomap(ip, flags, &lockmode);808 if (error)809 return error;810 811 /*812 * The reflink iflag could have changed since the earlier unlocked813 * check, check if it again and relock if needed.814 */815 if (xfs_is_cow_inode(ip) && lockmode == XFS_ILOCK_SHARED) {816 xfs_iunlock(ip, lockmode);817 lockmode = XFS_ILOCK_EXCL;818 goto relock;819 }820 821 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,822 &nimaps, 0);823 if (error)824 goto out_unlock;825 826 if (imap_needs_cow(ip, flags, &imap, nimaps)) {827 error = -EAGAIN;828 if (flags & IOMAP_NOWAIT)829 goto out_unlock;830 831 /* may drop and re-acquire the ilock */832 error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared,833 &lockmode,834 (flags & IOMAP_DIRECT) || IS_DAX(inode));835 if (error)836 goto out_unlock;837 if (shared)838 goto out_found_cow;839 end_fsb = imap.br_startoff + imap.br_blockcount;840 length = XFS_FSB_TO_B(mp, end_fsb) - offset;841 }842 843 if (imap_needs_alloc(inode, flags, &imap, nimaps))844 goto allocate_blocks;845 846 /*847 * NOWAIT and OVERWRITE I/O needs to span the entire requested I/O with848 * a single map so that we avoid partial IO failures due to the rest of849 * the I/O range not covered by this map triggering an EAGAIN condition850 * when it is subsequently mapped and aborting the I/O.851 */852 if (flags & (IOMAP_NOWAIT | IOMAP_OVERWRITE_ONLY)) {853 error = -EAGAIN;854 if (!imap_spans_range(&imap, offset_fsb, end_fsb))855 goto out_unlock;856 }857 858 /*859 * For overwrite only I/O, we cannot convert unwritten extents without860 * requiring sub-block zeroing. This can only be done under an861 * exclusive IOLOCK, hence return -EAGAIN if this is not a written862 * extent to tell the caller to try again.863 */864 if (flags & IOMAP_OVERWRITE_ONLY) {865 error = -EAGAIN;866 if (imap.br_state != XFS_EXT_NORM &&867 ((offset | length) & mp->m_blockmask))868 goto out_unlock;869 }870 871 seq = xfs_iomap_inode_sequence(ip, iomap_flags);872 xfs_iunlock(ip, lockmode);873 trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);874 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, iomap_flags, seq);875 876allocate_blocks:877 error = -EAGAIN;878 if (flags & (IOMAP_NOWAIT | IOMAP_OVERWRITE_ONLY))879 goto out_unlock;880 881 /*882 * We cap the maximum length we map to a sane size to keep the chunks883 * of work done where somewhat symmetric with the work writeback does.884 * This is a completely arbitrary number pulled out of thin air as a885 * best guess for initial testing.886 *887 * Note that the values needs to be less than 32-bits wide until the888 * lower level functions are updated.889 */890 length = min_t(loff_t, length, 1024 * PAGE_SIZE);891 end_fsb = xfs_iomap_end_fsb(mp, offset, length);892 893 if (offset + length > XFS_ISIZE(ip))894 end_fsb = xfs_iomap_eof_align_last_fsb(ip, end_fsb);895 else if (nimaps && imap.br_startblock == HOLESTARTBLOCK)896 end_fsb = min(end_fsb, imap.br_startoff + imap.br_blockcount);897 xfs_iunlock(ip, lockmode);898 899 error = xfs_iomap_write_direct(ip, offset_fsb, end_fsb - offset_fsb,900 flags, &imap, &seq);901 if (error)902 return error;903 904 trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap);905 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags,906 iomap_flags | IOMAP_F_NEW, seq);907 908out_found_cow:909 length = XFS_FSB_TO_B(mp, cmap.br_startoff + cmap.br_blockcount);910 trace_xfs_iomap_found(ip, offset, length - offset, XFS_COW_FORK, &cmap);911 if (imap.br_startblock != HOLESTARTBLOCK) {912 seq = xfs_iomap_inode_sequence(ip, 0);913 error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, seq);914 if (error)915 goto out_unlock;916 }917 seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);918 xfs_iunlock(ip, lockmode);919 return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, IOMAP_F_SHARED, seq);920 921out_unlock:922 if (lockmode)923 xfs_iunlock(ip, lockmode);924 return error;925}926 927const struct iomap_ops xfs_direct_write_iomap_ops = {928 .iomap_begin = xfs_direct_write_iomap_begin,929};930 931static int932xfs_dax_write_iomap_end(933 struct inode *inode,934 loff_t pos,935 loff_t length,936 ssize_t written,937 unsigned flags,938 struct iomap *iomap)939{940 struct xfs_inode *ip = XFS_I(inode);941 942 if (!xfs_is_cow_inode(ip))943 return 0;944 945 if (!written) {946 xfs_reflink_cancel_cow_range(ip, pos, length, true);947 return 0;948 }949 950 return xfs_reflink_end_cow(ip, pos, written);951}952 953const struct iomap_ops xfs_dax_write_iomap_ops = {954 .iomap_begin = xfs_direct_write_iomap_begin,955 .iomap_end = xfs_dax_write_iomap_end,956};957 958static int959xfs_buffered_write_iomap_begin(960 struct inode *inode,961 loff_t offset,962 loff_t count,963 unsigned flags,964 struct iomap *iomap,965 struct iomap *srcmap)966{967 struct xfs_inode *ip = XFS_I(inode);968 struct xfs_mount *mp = ip->i_mount;969 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);970 xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, count);971 struct xfs_bmbt_irec imap, cmap;972 struct xfs_iext_cursor icur, ccur;973 xfs_fsblock_t prealloc_blocks = 0;974 bool eof = false, cow_eof = false, shared = false;975 int allocfork = XFS_DATA_FORK;976 int error = 0;977 unsigned int lockmode = XFS_ILOCK_EXCL;978 unsigned int iomap_flags = 0;979 u64 seq;980 981 if (xfs_is_shutdown(mp))982 return -EIO;983 984 /* we can't use delayed allocations when using extent size hints */985 if (xfs_get_extsz_hint(ip))986 return xfs_direct_write_iomap_begin(inode, offset, count,987 flags, iomap, srcmap);988 989 error = xfs_qm_dqattach(ip);990 if (error)991 return error;992 993 error = xfs_ilock_for_iomap(ip, flags, &lockmode);994 if (error)995 return error;996 997 if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(&ip->i_df)) ||998 XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {999 xfs_bmap_mark_sick(ip, XFS_DATA_FORK);1000 error = -EFSCORRUPTED;1001 goto out_unlock;1002 }1003 1004 XFS_STATS_INC(mp, xs_blk_mapw);1005 1006 error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);1007 if (error)1008 goto out_unlock;1009 1010 /*1011 * Search the data fork first to look up our source mapping. We1012 * always need the data fork map, as we have to return it to the1013 * iomap code so that the higher level write code can read data in to1014 * perform read-modify-write cycles for unaligned writes.1015 */1016 eof = !xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap);1017 if (eof)1018 imap.br_startoff = end_fsb; /* fake hole until the end */1019 1020 /* We never need to allocate blocks for zeroing or unsharing a hole. */1021 if ((flags & (IOMAP_UNSHARE | IOMAP_ZERO)) &&1022 imap.br_startoff > offset_fsb) {1023 xfs_hole_to_iomap(ip, iomap, offset_fsb, imap.br_startoff);1024 goto out_unlock;1025 }1026 1027 /*1028 * For zeroing, trim a delalloc extent that extends beyond the EOF1029 * block. If it starts beyond the EOF block, convert it to an1030 * unwritten extent.1031 */1032 if ((flags & IOMAP_ZERO) && imap.br_startoff <= offset_fsb &&1033 isnullstartblock(imap.br_startblock)) {1034 xfs_fileoff_t eof_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));1035 1036 if (offset_fsb >= eof_fsb)1037 goto convert_delay;1038 if (end_fsb > eof_fsb) {1039 end_fsb = eof_fsb;1040 xfs_trim_extent(&imap, offset_fsb,1041 end_fsb - offset_fsb);1042 }1043 }1044 1045 /*1046 * Search the COW fork extent list even if we did not find a data fork1047 * extent. This serves two purposes: first this implements the1048 * speculative preallocation using cowextsize, so that we also unshare1049 * block adjacent to shared blocks instead of just the shared blocks1050 * themselves. Second the lookup in the extent list is generally faster1051 * than going out to the shared extent tree.1052 */1053 if (xfs_is_cow_inode(ip)) {1054 if (!ip->i_cowfp) {1055 ASSERT(!xfs_is_reflink_inode(ip));1056 xfs_ifork_init_cow(ip);1057 }1058 cow_eof = !xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb,1059 &ccur, &cmap);1060 if (!cow_eof && cmap.br_startoff <= offset_fsb) {1061 trace_xfs_reflink_cow_found(ip, &cmap);1062 goto found_cow;1063 }1064 }1065 1066 if (imap.br_startoff <= offset_fsb) {1067 /*1068 * For reflink files we may need a delalloc reservation when1069 * overwriting shared extents. This includes zeroing of1070 * existing extents that contain data.1071 */1072 if (!xfs_is_cow_inode(ip) ||1073 ((flags & IOMAP_ZERO) && imap.br_state != XFS_EXT_NORM)) {1074 trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,1075 &imap);1076 goto found_imap;1077 }1078 1079 xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);1080 1081 /* Trim the mapping to the nearest shared extent boundary. */1082 error = xfs_bmap_trim_cow(ip, &imap, &shared);1083 if (error)1084 goto out_unlock;1085 1086 /* Not shared? Just report the (potentially capped) extent. */1087 if (!shared) {1088 trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,1089 &imap);1090 goto found_imap;1091 }1092 1093 /*1094 * Fork all the shared blocks from our write offset until the1095 * end of the extent.1096 */1097 allocfork = XFS_COW_FORK;1098 end_fsb = imap.br_startoff + imap.br_blockcount;1099 } else {1100 /*1101 * We cap the maximum length we map here to MAX_WRITEBACK_PAGES1102 * pages to keep the chunks of work done where somewhat1103 * symmetric with the work writeback does. This is a completely1104 * arbitrary number pulled out of thin air.1105 *1106 * Note that the values needs to be less than 32-bits wide until1107 * the lower level functions are updated.1108 */1109 count = min_t(loff_t, count, 1024 * PAGE_SIZE);1110 end_fsb = xfs_iomap_end_fsb(mp, offset, count);1111 1112 if (xfs_is_always_cow_inode(ip))1113 allocfork = XFS_COW_FORK;1114 }1115 1116 if (eof && offset + count > XFS_ISIZE(ip)) {1117 /*1118 * Determine the initial size of the preallocation.1119 * We clean up any extra preallocation when the file is closed.1120 */1121 if (xfs_has_allocsize(mp))1122 prealloc_blocks = mp->m_allocsize_blocks;1123 else if (allocfork == XFS_DATA_FORK)1124 prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork,1125 offset, count, &icur);1126 else1127 prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork,1128 offset, count, &ccur);1129 if (prealloc_blocks) {1130 xfs_extlen_t align;1131 xfs_off_t end_offset;1132 xfs_fileoff_t p_end_fsb;1133 1134 end_offset = XFS_ALLOC_ALIGN(mp, offset + count - 1);1135 p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) +1136 prealloc_blocks;1137 1138 align = xfs_eof_alignment(ip);1139 if (align)1140 p_end_fsb = roundup_64(p_end_fsb, align);1141 1142 p_end_fsb = min(p_end_fsb,1143 XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));1144 ASSERT(p_end_fsb > offset_fsb);1145 prealloc_blocks = p_end_fsb - end_fsb;1146 }1147 }1148 1149 /*1150 * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch1151 * them out if the write happens to fail.1152 */1153 iomap_flags |= IOMAP_F_NEW;1154 if (allocfork == XFS_COW_FORK) {1155 error = xfs_bmapi_reserve_delalloc(ip, allocfork, offset_fsb,1156 end_fsb - offset_fsb, prealloc_blocks, &cmap,1157 &ccur, cow_eof);1158 if (error)1159 goto out_unlock;1160 1161 trace_xfs_iomap_alloc(ip, offset, count, allocfork, &cmap);1162 goto found_cow;1163 }1164 1165 error = xfs_bmapi_reserve_delalloc(ip, allocfork, offset_fsb,1166 end_fsb - offset_fsb, prealloc_blocks, &imap, &icur,1167 eof);1168 if (error)1169 goto out_unlock;1170 1171 trace_xfs_iomap_alloc(ip, offset, count, allocfork, &imap);1172found_imap:1173 seq = xfs_iomap_inode_sequence(ip, iomap_flags);1174 xfs_iunlock(ip, lockmode);1175 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, iomap_flags, seq);1176 1177convert_delay:1178 xfs_iunlock(ip, lockmode);1179 truncate_pagecache(inode, offset);1180 error = xfs_bmapi_convert_delalloc(ip, XFS_DATA_FORK, offset,1181 iomap, NULL);1182 if (error)1183 return error;1184 1185 trace_xfs_iomap_alloc(ip, offset, count, XFS_DATA_FORK, &imap);1186 return 0;1187 1188found_cow:1189 if (imap.br_startoff <= offset_fsb) {1190 error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0,1191 xfs_iomap_inode_sequence(ip, 0));1192 if (error)1193 goto out_unlock;1194 } else {1195 xfs_trim_extent(&cmap, offset_fsb,1196 imap.br_startoff - offset_fsb);1197 }1198 1199 iomap_flags |= IOMAP_F_SHARED;1200 seq = xfs_iomap_inode_sequence(ip, iomap_flags);1201 xfs_iunlock(ip, lockmode);1202 return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, iomap_flags, seq);1203 1204out_unlock:1205 xfs_iunlock(ip, lockmode);1206 return error;1207}1208 1209static void1210xfs_buffered_write_delalloc_punch(1211 struct inode *inode,1212 loff_t offset,1213 loff_t length,1214 struct iomap *iomap)1215{1216 xfs_bmap_punch_delalloc_range(XFS_I(inode),1217 (iomap->flags & IOMAP_F_SHARED) ?1218 XFS_COW_FORK : XFS_DATA_FORK,1219 offset, offset + length);1220}1221 1222static int1223xfs_buffered_write_iomap_end(1224 struct inode *inode,1225 loff_t offset,1226 loff_t length,1227 ssize_t written,1228 unsigned flags,1229 struct iomap *iomap)1230{1231 loff_t start_byte, end_byte;1232 1233 /* If we didn't reserve the blocks, we're not allowed to punch them. */1234 if (iomap->type != IOMAP_DELALLOC || !(iomap->flags & IOMAP_F_NEW))1235 return 0;1236 1237 /* Nothing to do if we've written the entire delalloc extent */1238 start_byte = iomap_last_written_block(inode, offset, written);1239 end_byte = round_up(offset + length, i_blocksize(inode));1240 if (start_byte >= end_byte)1241 return 0;1242 1243 /* For zeroing operations the callers already hold invalidate_lock. */1244 if (flags & (IOMAP_UNSHARE | IOMAP_ZERO)) {1245 rwsem_assert_held_write(&inode->i_mapping->invalidate_lock);1246 iomap_write_delalloc_release(inode, start_byte, end_byte, flags,1247 iomap, xfs_buffered_write_delalloc_punch);1248 } else {1249 filemap_invalidate_lock(inode->i_mapping);1250 iomap_write_delalloc_release(inode, start_byte, end_byte, flags,1251 iomap, xfs_buffered_write_delalloc_punch);1252 filemap_invalidate_unlock(inode->i_mapping);1253 }1254 1255 return 0;1256}1257 1258const struct iomap_ops xfs_buffered_write_iomap_ops = {1259 .iomap_begin = xfs_buffered_write_iomap_begin,1260 .iomap_end = xfs_buffered_write_iomap_end,1261};1262 1263/*1264 * iomap_page_mkwrite() will never fail in a way that requires delalloc extents1265 * that it allocated to be revoked. Hence we do not need an .iomap_end method1266 * for this operation.1267 */1268const struct iomap_ops xfs_page_mkwrite_iomap_ops = {1269 .iomap_begin = xfs_buffered_write_iomap_begin,1270};1271 1272static int1273xfs_read_iomap_begin(1274 struct inode *inode,1275 loff_t offset,1276 loff_t length,1277 unsigned flags,1278 struct iomap *iomap,1279 struct iomap *srcmap)1280{1281 struct xfs_inode *ip = XFS_I(inode);1282 struct xfs_mount *mp = ip->i_mount;1283 struct xfs_bmbt_irec imap;1284 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);1285 xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length);1286 int nimaps = 1, error = 0;1287 bool shared = false;1288 unsigned int lockmode = XFS_ILOCK_SHARED;1289 u64 seq;1290 1291 ASSERT(!(flags & (IOMAP_WRITE | IOMAP_ZERO)));1292 1293 if (xfs_is_shutdown(mp))1294 return -EIO;1295 1296 error = xfs_ilock_for_iomap(ip, flags, &lockmode);1297 if (error)1298 return error;1299 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,1300 &nimaps, 0);1301 if (!error && ((flags & IOMAP_REPORT) || IS_DAX(inode)))1302 error = xfs_reflink_trim_around_shared(ip, &imap, &shared);1303 seq = xfs_iomap_inode_sequence(ip, shared ? IOMAP_F_SHARED : 0);1304 xfs_iunlock(ip, lockmode);1305 1306 if (error)1307 return error;1308 trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);1309 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags,1310 shared ? IOMAP_F_SHARED : 0, seq);1311}1312 1313const struct iomap_ops xfs_read_iomap_ops = {1314 .iomap_begin = xfs_read_iomap_begin,1315};1316 1317static int1318xfs_seek_iomap_begin(1319 struct inode *inode,1320 loff_t offset,1321 loff_t length,1322 unsigned flags,1323 struct iomap *iomap,1324 struct iomap *srcmap)1325{1326 struct xfs_inode *ip = XFS_I(inode);1327 struct xfs_mount *mp = ip->i_mount;1328 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);1329 xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + length);1330 xfs_fileoff_t cow_fsb = NULLFILEOFF, data_fsb = NULLFILEOFF;1331 struct xfs_iext_cursor icur;1332 struct xfs_bmbt_irec imap, cmap;1333 int error = 0;1334 unsigned lockmode;1335 u64 seq;1336 1337 if (xfs_is_shutdown(mp))1338 return -EIO;1339 1340 lockmode = xfs_ilock_data_map_shared(ip);1341 error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);1342 if (error)1343 goto out_unlock;1344 1345 if (xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap)) {1346 /*1347 * If we found a data extent we are done.1348 */1349 if (imap.br_startoff <= offset_fsb)1350 goto done;1351 data_fsb = imap.br_startoff;1352 } else {1353 /*1354 * Fake a hole until the end of the file.1355 */1356 data_fsb = xfs_iomap_end_fsb(mp, offset, length);1357 }1358 1359 /*1360 * If a COW fork extent covers the hole, report it - capped to the next1361 * data fork extent:1362 */1363 if (xfs_inode_has_cow_data(ip) &&1364 xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap))1365 cow_fsb = cmap.br_startoff;1366 if (cow_fsb != NULLFILEOFF && cow_fsb <= offset_fsb) {1367 if (data_fsb < cow_fsb + cmap.br_blockcount)1368 end_fsb = min(end_fsb, data_fsb);1369 xfs_trim_extent(&cmap, offset_fsb, end_fsb - offset_fsb);1370 seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);1371 error = xfs_bmbt_to_iomap(ip, iomap, &cmap, flags,1372 IOMAP_F_SHARED, seq);1373 /*1374 * This is a COW extent, so we must probe the page cache1375 * because there could be dirty page cache being backed1376 * by this extent.1377 */1378 iomap->type = IOMAP_UNWRITTEN;1379 goto out_unlock;1380 }1381 1382 /*1383 * Else report a hole, capped to the next found data or COW extent.1384 */1385 if (cow_fsb != NULLFILEOFF && cow_fsb < data_fsb)1386 imap.br_blockcount = cow_fsb - offset_fsb;1387 else1388 imap.br_blockcount = data_fsb - offset_fsb;1389 imap.br_startoff = offset_fsb;1390 imap.br_startblock = HOLESTARTBLOCK;1391 imap.br_state = XFS_EXT_NORM;1392done:1393 seq = xfs_iomap_inode_sequence(ip, 0);1394 xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);1395 error = xfs_bmbt_to_iomap(ip, iomap, &imap, flags, 0, seq);1396out_unlock:1397 xfs_iunlock(ip, lockmode);1398 return error;1399}1400 1401const struct iomap_ops xfs_seek_iomap_ops = {1402 .iomap_begin = xfs_seek_iomap_begin,1403};1404 1405static int1406xfs_xattr_iomap_begin(1407 struct inode *inode,1408 loff_t offset,1409 loff_t length,1410 unsigned flags,1411 struct iomap *iomap,1412 struct iomap *srcmap)1413{1414 struct xfs_inode *ip = XFS_I(inode);1415 struct xfs_mount *mp = ip->i_mount;1416 xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);1417 xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + length);1418 struct xfs_bmbt_irec imap;1419 int nimaps = 1, error = 0;1420 unsigned lockmode;1421 int seq;1422 1423 if (xfs_is_shutdown(mp))1424 return -EIO;1425 1426 lockmode = xfs_ilock_attr_map_shared(ip);1427 1428 /* if there are no attribute fork or extents, return ENOENT */1429 if (!xfs_inode_has_attr_fork(ip) || !ip->i_af.if_nextents) {1430 error = -ENOENT;1431 goto out_unlock;1432 }1433 1434 ASSERT(ip->i_af.if_format != XFS_DINODE_FMT_LOCAL);1435 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,1436 &nimaps, XFS_BMAPI_ATTRFORK);1437out_unlock:1438 1439 seq = xfs_iomap_inode_sequence(ip, IOMAP_F_XATTR);1440 xfs_iunlock(ip, lockmode);1441 1442 if (error)1443 return error;1444 ASSERT(nimaps);1445 return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, IOMAP_F_XATTR, seq);1446}1447 1448const struct iomap_ops xfs_xattr_iomap_ops = {1449 .iomap_begin = xfs_xattr_iomap_begin,1450};1451 1452int1453xfs_zero_range(1454 struct xfs_inode *ip,1455 loff_t pos,1456 loff_t len,1457 bool *did_zero)1458{1459 struct inode *inode = VFS_I(ip);1460 1461 xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);1462 1463 if (IS_DAX(inode))1464 return dax_zero_range(inode, pos, len, did_zero,1465 &xfs_dax_write_iomap_ops);1466 return iomap_zero_range(inode, pos, len, did_zero,1467 &xfs_buffered_write_iomap_ops);1468}1469 1470int1471xfs_truncate_page(1472 struct xfs_inode *ip,1473 loff_t pos,1474 bool *did_zero)1475{1476 struct inode *inode = VFS_I(ip);1477 1478 if (IS_DAX(inode))1479 return dax_truncate_page(inode, pos, did_zero,1480 &xfs_dax_write_iomap_ops);1481 return iomap_truncate_page(inode, pos, did_zero,1482 &xfs_buffered_write_iomap_ops);1483}1484