2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #include "xfs_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_format.h"
28 #include "xfs_da_btree.h"
29 #include "xfs_inode.h"
30 #include "xfs_trans.h"
31 #include "xfs_inode_item.h"
33 #include "xfs_bmap_util.h"
34 #include "xfs_error.h"
36 #include "xfs_dir2_priv.h"
37 #include "xfs_ioctl.h"
38 #include "xfs_trace.h"
40 #include "xfs_dinode.h"
42 #include <linux/aio.h>
43 #include <linux/dcache.h>
44 #include <linux/falloc.h>
45 #include <linux/pagevec.h>
47 static const struct vm_operations_struct xfs_file_vm_ops;
50 * Locking primitives for read and write IO paths to ensure we consistently use
51 * and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
58 if (type & XFS_IOLOCK_EXCL)
59 mutex_lock(&VFS_I(ip)->i_mutex);
68 xfs_iunlock(ip, type);
69 if (type & XFS_IOLOCK_EXCL)
70 mutex_unlock(&VFS_I(ip)->i_mutex);
78 xfs_ilock_demote(ip, type);
79 if (type & XFS_IOLOCK_EXCL)
80 mutex_unlock(&VFS_I(ip)->i_mutex);
86 * xfs_iozero clears the specified range of buffer supplied,
87 * and marks all the affected blocks as valid and modified. If
88 * an affected block is not allocated, it will be allocated. If
89 * an affected block is not completely overwritten, and is not
90 * valid before the operation, it will be read from disk before
91 * being partially zeroed.
95 struct xfs_inode *ip, /* inode */
96 loff_t pos, /* offset in file */
97 size_t count) /* size of data to zero */
100 struct address_space *mapping;
103 mapping = VFS_I(ip)->i_mapping;
105 unsigned offset, bytes;
108 offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
109 bytes = PAGE_CACHE_SIZE - offset;
113 status = pagecache_write_begin(NULL, mapping, pos, bytes,
114 AOP_FLAG_UNINTERRUPTIBLE,
119 zero_user(page, offset, bytes);
121 status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
123 WARN_ON(status <= 0); /* can't return less than zero! */
133 * Fsync operations on directories are much simpler than on regular files,
134 * as there is no file data to flush, and thus also no need for explicit
135 * cache flush operations, and there are no non-transaction metadata updates
136 * on directories either.
145 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
146 struct xfs_mount *mp = ip->i_mount;
149 trace_xfs_dir_fsync(ip);
151 xfs_ilock(ip, XFS_ILOCK_SHARED);
152 if (xfs_ipincount(ip))
153 lsn = ip->i_itemp->ili_last_lsn;
154 xfs_iunlock(ip, XFS_ILOCK_SHARED);
158 return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
168 struct inode *inode = file->f_mapping->host;
169 struct xfs_inode *ip = XFS_I(inode);
170 struct xfs_mount *mp = ip->i_mount;
175 trace_xfs_file_fsync(ip);
177 error = filemap_write_and_wait_range(inode->i_mapping, start, end);
181 if (XFS_FORCED_SHUTDOWN(mp))
182 return -XFS_ERROR(EIO);
184 xfs_iflags_clear(ip, XFS_ITRUNCATED);
186 if (mp->m_flags & XFS_MOUNT_BARRIER) {
188 * If we have an RT and/or log subvolume we need to make sure
189 * to flush the write cache the device used for file data
190 * first. This is to ensure newly written file data make
191 * it to disk before logging the new inode size in case of
192 * an extending write.
194 if (XFS_IS_REALTIME_INODE(ip))
195 xfs_blkdev_issue_flush(mp->m_rtdev_targp);
196 else if (mp->m_logdev_targp != mp->m_ddev_targp)
197 xfs_blkdev_issue_flush(mp->m_ddev_targp);
201 * All metadata updates are logged, which means that we just have
202 * to flush the log up to the latest LSN that touched the inode.
204 xfs_ilock(ip, XFS_ILOCK_SHARED);
205 if (xfs_ipincount(ip)) {
207 (ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
208 lsn = ip->i_itemp->ili_last_lsn;
210 xfs_iunlock(ip, XFS_ILOCK_SHARED);
213 error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
216 * If we only have a single device, and the log force about was
217 * a no-op we might have to flush the data device cache here.
218 * This can only happen for fdatasync/O_DSYNC if we were overwriting
219 * an already allocated file and thus do not have any metadata to
222 if ((mp->m_flags & XFS_MOUNT_BARRIER) &&
223 mp->m_logdev_targp == mp->m_ddev_targp &&
224 !XFS_IS_REALTIME_INODE(ip) &&
226 xfs_blkdev_issue_flush(mp->m_ddev_targp);
234 const struct iovec *iovp,
235 unsigned long nr_segs,
238 struct file *file = iocb->ki_filp;
239 struct inode *inode = file->f_mapping->host;
240 struct xfs_inode *ip = XFS_I(inode);
241 struct xfs_mount *mp = ip->i_mount;
247 XFS_STATS_INC(xs_read_calls);
249 BUG_ON(iocb->ki_pos != pos);
251 if (unlikely(file->f_flags & O_DIRECT))
252 ioflags |= IO_ISDIRECT;
253 if (file->f_mode & FMODE_NOCMTIME)
256 ret = generic_segment_checks(iovp, &nr_segs, &size, VERIFY_WRITE);
260 if (unlikely(ioflags & IO_ISDIRECT)) {
261 xfs_buftarg_t *target =
262 XFS_IS_REALTIME_INODE(ip) ?
263 mp->m_rtdev_targp : mp->m_ddev_targp;
264 if ((pos | size) & target->bt_meta_sectormask) {
265 if (pos == i_size_read(inode))
267 return -XFS_ERROR(EINVAL);
271 n = mp->m_super->s_maxbytes - pos;
272 if (n <= 0 || size == 0)
278 if (XFS_FORCED_SHUTDOWN(mp))
282 * Locking is a bit tricky here. If we take an exclusive lock
283 * for direct IO, we effectively serialise all new concurrent
284 * read IO to this file and block it behind IO that is currently in
285 * progress because IO in progress holds the IO lock shared. We only
286 * need to hold the lock exclusive to blow away the page cache, so
287 * only take lock exclusively if the page cache needs invalidation.
288 * This allows the normal direct IO case of no page cache pages to
289 * proceeed concurrently without serialisation.
291 xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
292 if ((ioflags & IO_ISDIRECT) && inode->i_mapping->nrpages) {
293 xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
294 xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
296 if (inode->i_mapping->nrpages) {
297 ret = -filemap_write_and_wait_range(
298 VFS_I(ip)->i_mapping,
301 xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
304 truncate_pagecache_range(VFS_I(ip), pos, -1);
306 xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
309 trace_xfs_file_read(ip, size, pos, ioflags);
311 ret = generic_file_aio_read(iocb, iovp, nr_segs, pos);
313 XFS_STATS_ADD(xs_read_bytes, ret);
315 xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
320 xfs_file_splice_read(
323 struct pipe_inode_info *pipe,
327 struct xfs_inode *ip = XFS_I(infilp->f_mapping->host);
331 XFS_STATS_INC(xs_read_calls);
333 if (infilp->f_mode & FMODE_NOCMTIME)
336 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
339 xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
341 trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
343 ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
345 XFS_STATS_ADD(xs_read_bytes, ret);
347 xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
352 * xfs_file_splice_write() does not use xfs_rw_ilock() because
353 * generic_file_splice_write() takes the i_mutex itself. This, in theory,
354 * couuld cause lock inversions between the aio_write path and the splice path
355 * if someone is doing concurrent splice(2) based writes and write(2) based
356 * writes to the same inode. The only real way to fix this is to re-implement
357 * the generic code here with correct locking orders.
360 xfs_file_splice_write(
361 struct pipe_inode_info *pipe,
362 struct file *outfilp,
367 struct inode *inode = outfilp->f_mapping->host;
368 struct xfs_inode *ip = XFS_I(inode);
372 XFS_STATS_INC(xs_write_calls);
374 if (outfilp->f_mode & FMODE_NOCMTIME)
377 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
380 xfs_ilock(ip, XFS_IOLOCK_EXCL);
382 trace_xfs_file_splice_write(ip, count, *ppos, ioflags);
384 ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
386 XFS_STATS_ADD(xs_write_bytes, ret);
388 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
393 * This routine is called to handle zeroing any space in the last block of the
394 * file that is beyond the EOF. We do this since the size is being increased
395 * without writing anything to that block and we don't want to read the
396 * garbage on the disk.
398 STATIC int /* error (positive) */
400 struct xfs_inode *ip,
404 struct xfs_mount *mp = ip->i_mount;
405 xfs_fileoff_t last_fsb = XFS_B_TO_FSBT(mp, isize);
406 int zero_offset = XFS_B_FSB_OFFSET(mp, isize);
410 struct xfs_bmbt_irec imap;
412 xfs_ilock(ip, XFS_ILOCK_EXCL);
413 error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
414 xfs_iunlock(ip, XFS_ILOCK_EXCL);
421 * If the block underlying isize is just a hole, then there
422 * is nothing to zero.
424 if (imap.br_startblock == HOLESTARTBLOCK)
427 zero_len = mp->m_sb.sb_blocksize - zero_offset;
428 if (isize + zero_len > offset)
429 zero_len = offset - isize;
430 return xfs_iozero(ip, isize, zero_len);
434 * Zero any on disk space between the current EOF and the new, larger EOF.
436 * This handles the normal case of zeroing the remainder of the last block in
437 * the file and the unusual case of zeroing blocks out beyond the size of the
438 * file. This second case only happens with fixed size extents and when the
439 * system crashes before the inode size was updated but after blocks were
442 * Expects the iolock to be held exclusive, and will take the ilock internally.
444 int /* error (positive) */
446 struct xfs_inode *ip,
447 xfs_off_t offset, /* starting I/O offset */
448 xfs_fsize_t isize) /* current inode size */
450 struct xfs_mount *mp = ip->i_mount;
451 xfs_fileoff_t start_zero_fsb;
452 xfs_fileoff_t end_zero_fsb;
453 xfs_fileoff_t zero_count_fsb;
454 xfs_fileoff_t last_fsb;
455 xfs_fileoff_t zero_off;
456 xfs_fsize_t zero_len;
459 struct xfs_bmbt_irec imap;
461 ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
462 ASSERT(offset > isize);
465 * First handle zeroing the block on which isize resides.
467 * We only zero a part of that block so it is handled specially.
469 if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
470 error = xfs_zero_last_block(ip, offset, isize);
476 * Calculate the range between the new size and the old where blocks
477 * needing to be zeroed may exist.
479 * To get the block where the last byte in the file currently resides,
480 * we need to subtract one from the size and truncate back to a block
481 * boundary. We subtract 1 in case the size is exactly on a block
484 last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
485 start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
486 end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
487 ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
488 if (last_fsb == end_zero_fsb) {
490 * The size was only incremented on its last block.
491 * We took care of that above, so just return.
496 ASSERT(start_zero_fsb <= end_zero_fsb);
497 while (start_zero_fsb <= end_zero_fsb) {
499 zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
501 xfs_ilock(ip, XFS_ILOCK_EXCL);
502 error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
504 xfs_iunlock(ip, XFS_ILOCK_EXCL);
510 if (imap.br_state == XFS_EXT_UNWRITTEN ||
511 imap.br_startblock == HOLESTARTBLOCK) {
512 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
513 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
518 * There are blocks we need to zero.
520 zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
521 zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
523 if ((zero_off + zero_len) > offset)
524 zero_len = offset - zero_off;
526 error = xfs_iozero(ip, zero_off, zero_len);
530 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
531 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
538 * Common pre-write limit and setup checks.
540 * Called with the iolocked held either shared and exclusive according to
541 * @iolock, and returns with it held. Might upgrade the iolock to exclusive
542 * if called for a direct write beyond i_size.
545 xfs_file_aio_write_checks(
551 struct inode *inode = file->f_mapping->host;
552 struct xfs_inode *ip = XFS_I(inode);
556 error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
561 * If the offset is beyond the size of the file, we need to zero any
562 * blocks that fall between the existing EOF and the start of this
563 * write. If zeroing is needed and we are currently holding the
564 * iolock shared, we need to update it to exclusive which implies
565 * having to redo all checks before.
567 if (*pos > i_size_read(inode)) {
568 if (*iolock == XFS_IOLOCK_SHARED) {
569 xfs_rw_iunlock(ip, *iolock);
570 *iolock = XFS_IOLOCK_EXCL;
571 xfs_rw_ilock(ip, *iolock);
574 error = -xfs_zero_eof(ip, *pos, i_size_read(inode));
580 * Updating the timestamps will grab the ilock again from
581 * xfs_fs_dirty_inode, so we have to call it after dropping the
582 * lock above. Eventually we should look into a way to avoid
583 * the pointless lock roundtrip.
585 if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
586 error = file_update_time(file);
592 * If we're writing the file then make sure to clear the setuid and
593 * setgid bits if the process is not being run by root. This keeps
594 * people from modifying setuid and setgid binaries.
596 return file_remove_suid(file);
600 * xfs_file_dio_aio_write - handle direct IO writes
602 * Lock the inode appropriately to prepare for and issue a direct IO write.
603 * By separating it from the buffered write path we remove all the tricky to
604 * follow locking changes and looping.
606 * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
607 * until we're sure the bytes at the new EOF have been zeroed and/or the cached
608 * pages are flushed out.
610 * In most cases the direct IO writes will be done holding IOLOCK_SHARED
611 * allowing them to be done in parallel with reads and other direct IO writes.
612 * However, if the IO is not aligned to filesystem blocks, the direct IO layer
613 * needs to do sub-block zeroing and that requires serialisation against other
614 * direct IOs to the same block. In this case we need to serialise the
615 * submission of the unaligned IOs so that we don't get racing block zeroing in
616 * the dio layer. To avoid the problem with aio, we also need to wait for
617 * outstanding IOs to complete so that unwritten extent conversion is completed
618 * before we try to map the overlapping block. This is currently implemented by
619 * hitting it with a big hammer (i.e. inode_dio_wait()).
621 * Returns with locks held indicated by @iolock and errors indicated by
622 * negative return values.
625 xfs_file_dio_aio_write(
627 const struct iovec *iovp,
628 unsigned long nr_segs,
632 struct file *file = iocb->ki_filp;
633 struct address_space *mapping = file->f_mapping;
634 struct inode *inode = mapping->host;
635 struct xfs_inode *ip = XFS_I(inode);
636 struct xfs_mount *mp = ip->i_mount;
638 size_t count = ocount;
639 int unaligned_io = 0;
641 struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
642 mp->m_rtdev_targp : mp->m_ddev_targp;
644 if ((pos | count) & target->bt_meta_sectormask)
645 return -XFS_ERROR(EINVAL);
647 if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
651 * We don't need to take an exclusive lock unless there page cache needs
652 * to be invalidated or unaligned IO is being executed. We don't need to
653 * consider the EOF extension case here because
654 * xfs_file_aio_write_checks() will relock the inode as necessary for
655 * EOF zeroing cases and fill out the new inode size as appropriate.
657 if (unaligned_io || mapping->nrpages)
658 iolock = XFS_IOLOCK_EXCL;
660 iolock = XFS_IOLOCK_SHARED;
661 xfs_rw_ilock(ip, iolock);
664 * Recheck if there are cached pages that need invalidate after we got
665 * the iolock to protect against other threads adding new pages while
666 * we were waiting for the iolock.
668 if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
669 xfs_rw_iunlock(ip, iolock);
670 iolock = XFS_IOLOCK_EXCL;
671 xfs_rw_ilock(ip, iolock);
674 ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
678 if (mapping->nrpages) {
679 ret = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
683 truncate_pagecache_range(VFS_I(ip), pos, -1);
687 * If we are doing unaligned IO, wait for all other IO to drain,
688 * otherwise demote the lock if we had to flush cached pages
691 inode_dio_wait(inode);
692 else if (iolock == XFS_IOLOCK_EXCL) {
693 xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
694 iolock = XFS_IOLOCK_SHARED;
697 trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
698 ret = generic_file_direct_write(iocb, iovp,
699 &nr_segs, pos, &iocb->ki_pos, count, ocount);
702 xfs_rw_iunlock(ip, iolock);
704 /* No fallback to buffered IO on errors for XFS. */
705 ASSERT(ret < 0 || ret == count);
710 xfs_file_buffered_aio_write(
712 const struct iovec *iovp,
713 unsigned long nr_segs,
717 struct file *file = iocb->ki_filp;
718 struct address_space *mapping = file->f_mapping;
719 struct inode *inode = mapping->host;
720 struct xfs_inode *ip = XFS_I(inode);
723 int iolock = XFS_IOLOCK_EXCL;
724 size_t count = ocount;
726 xfs_rw_ilock(ip, iolock);
728 ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
732 /* We can write back this queue in page reclaim */
733 current->backing_dev_info = mapping->backing_dev_info;
736 trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0);
737 ret = generic_file_buffered_write(iocb, iovp, nr_segs,
738 pos, &iocb->ki_pos, count, 0);
741 * If we just got an ENOSPC, try to write back all dirty inodes to
742 * convert delalloc space to free up some of the excess reserved
745 if (ret == -ENOSPC && !enospc) {
747 xfs_flush_inodes(ip->i_mount);
751 current->backing_dev_info = NULL;
753 xfs_rw_iunlock(ip, iolock);
760 const struct iovec *iovp,
761 unsigned long nr_segs,
764 struct file *file = iocb->ki_filp;
765 struct address_space *mapping = file->f_mapping;
766 struct inode *inode = mapping->host;
767 struct xfs_inode *ip = XFS_I(inode);
771 XFS_STATS_INC(xs_write_calls);
773 BUG_ON(iocb->ki_pos != pos);
775 ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
782 if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
787 if (unlikely(file->f_flags & O_DIRECT))
788 ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
790 ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
796 XFS_STATS_ADD(xs_write_bytes, ret);
798 /* Handle various SYNC-type writes */
799 err = generic_write_sync(file, pos, ret);
815 struct inode *inode = file_inode(file);
816 struct xfs_inode *ip = XFS_I(inode);
817 struct xfs_trans *tp;
821 if (!S_ISREG(inode->i_mode))
823 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
826 xfs_ilock(ip, XFS_IOLOCK_EXCL);
827 if (mode & FALLOC_FL_PUNCH_HOLE) {
828 error = xfs_free_file_space(ip, offset, len);
832 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
833 offset + len > i_size_read(inode)) {
834 new_size = offset + len;
835 error = -inode_newsize_ok(inode, new_size);
840 error = xfs_alloc_file_space(ip, offset, len,
846 tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_WRITEID);
847 error = xfs_trans_reserve(tp, &M_RES(ip->i_mount)->tr_writeid, 0, 0);
849 xfs_trans_cancel(tp, 0);
853 xfs_ilock(ip, XFS_ILOCK_EXCL);
854 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
855 ip->i_d.di_mode &= ~S_ISUID;
856 if (ip->i_d.di_mode & S_IXGRP)
857 ip->i_d.di_mode &= ~S_ISGID;
859 if (!(mode & FALLOC_FL_PUNCH_HOLE))
860 ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
862 xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
863 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
865 if (file->f_flags & O_DSYNC)
866 xfs_trans_set_sync(tp);
867 error = xfs_trans_commit(tp, 0);
871 /* Change file size if needed */
875 iattr.ia_valid = ATTR_SIZE;
876 iattr.ia_size = new_size;
877 error = xfs_setattr_size(ip, &iattr);
881 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
891 if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
893 if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
903 struct xfs_inode *ip = XFS_I(inode);
907 error = xfs_file_open(inode, file);
912 * If there are any blocks, read-ahead block 0 as we're almost
913 * certain to have the next operation be a read there.
915 mode = xfs_ilock_data_map_shared(ip);
916 if (ip->i_d.di_nextents > 0)
917 xfs_dir3_data_readahead(NULL, ip, 0, -1);
918 xfs_iunlock(ip, mode);
927 return -xfs_release(XFS_I(inode));
933 struct dir_context *ctx)
935 struct inode *inode = file_inode(file);
936 xfs_inode_t *ip = XFS_I(inode);
941 * The Linux API doesn't pass down the total size of the buffer
942 * we read into down to the filesystem. With the filldir concept
943 * it's not needed for correct information, but the XFS dir2 leaf
944 * code wants an estimate of the buffer size to calculate it's
945 * readahead window and size the buffers used for mapping to
948 * Try to give it an estimate that's good enough, maybe at some
949 * point we can change the ->readdir prototype to include the
950 * buffer size. For now we use the current glibc buffer size.
952 bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
954 error = xfs_readdir(ip, ctx, bufsize);
963 struct vm_area_struct *vma)
965 vma->vm_ops = &xfs_file_vm_ops;
972 * mmap()d file has taken write protection fault and is being made
973 * writable. We can set the page state up correctly for a writable
974 * page, which means we can do correct delalloc accounting (ENOSPC
975 * checking!) and unwritten extent mapping.
979 struct vm_area_struct *vma,
980 struct vm_fault *vmf)
982 return block_page_mkwrite(vma, vmf, xfs_get_blocks);
986 * This type is designed to indicate the type of offset we would like
987 * to search from page cache for either xfs_seek_data() or xfs_seek_hole().
995 * Lookup the desired type of offset from the given page.
997 * On success, return true and the offset argument will point to the
998 * start of the region that was found. Otherwise this function will
999 * return false and keep the offset argument unchanged.
1002 xfs_lookup_buffer_offset(
1007 loff_t lastoff = page_offset(page);
1009 struct buffer_head *bh, *head;
1011 bh = head = page_buffers(page);
1014 * Unwritten extents that have data in the page
1015 * cache covering them can be identified by the
1016 * BH_Unwritten state flag. Pages with multiple
1017 * buffers might have a mix of holes, data and
1018 * unwritten extents - any buffer with valid
1019 * data in it should have BH_Uptodate flag set
1022 if (buffer_unwritten(bh) ||
1023 buffer_uptodate(bh)) {
1024 if (type == DATA_OFF)
1027 if (type == HOLE_OFF)
1035 lastoff += bh->b_size;
1036 } while ((bh = bh->b_this_page) != head);
1042 * This routine is called to find out and return a data or hole offset
1043 * from the page cache for unwritten extents according to the desired
1044 * type for xfs_seek_data() or xfs_seek_hole().
1046 * The argument offset is used to tell where we start to search from the
1047 * page cache. Map is used to figure out the end points of the range to
1050 * Return true if the desired type of offset was found, and the argument
1051 * offset is filled with that address. Otherwise, return false and keep
1055 xfs_find_get_desired_pgoff(
1056 struct inode *inode,
1057 struct xfs_bmbt_irec *map,
1061 struct xfs_inode *ip = XFS_I(inode);
1062 struct xfs_mount *mp = ip->i_mount;
1063 struct pagevec pvec;
1067 loff_t startoff = *offset;
1068 loff_t lastoff = startoff;
1071 pagevec_init(&pvec, 0);
1073 index = startoff >> PAGE_CACHE_SHIFT;
1074 endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
1075 end = endoff >> PAGE_CACHE_SHIFT;
1081 want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
1082 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
1085 * No page mapped into given range. If we are searching holes
1086 * and if this is the first time we got into the loop, it means
1087 * that the given offset is landed in a hole, return it.
1089 * If we have already stepped through some block buffers to find
1090 * holes but they all contains data. In this case, the last
1091 * offset is already updated and pointed to the end of the last
1092 * mapped page, if it does not reach the endpoint to search,
1093 * that means there should be a hole between them.
1095 if (nr_pages == 0) {
1096 /* Data search found nothing */
1097 if (type == DATA_OFF)
1100 ASSERT(type == HOLE_OFF);
1101 if (lastoff == startoff || lastoff < endoff) {
1109 * At lease we found one page. If this is the first time we
1110 * step into the loop, and if the first page index offset is
1111 * greater than the given search offset, a hole was found.
1113 if (type == HOLE_OFF && lastoff == startoff &&
1114 lastoff < page_offset(pvec.pages[0])) {
1119 for (i = 0; i < nr_pages; i++) {
1120 struct page *page = pvec.pages[i];
1124 * At this point, the page may be truncated or
1125 * invalidated (changing page->mapping to NULL),
1126 * or even swizzled back from swapper_space to tmpfs
1127 * file mapping. However, page->index will not change
1128 * because we have a reference on the page.
1130 * Searching done if the page index is out of range.
1131 * If the current offset is not reaches the end of
1132 * the specified search range, there should be a hole
1135 if (page->index > end) {
1136 if (type == HOLE_OFF && lastoff < endoff) {
1145 * Page truncated or invalidated(page->mapping == NULL).
1146 * We can freely skip it and proceed to check the next
1149 if (unlikely(page->mapping != inode->i_mapping)) {
1154 if (!page_has_buffers(page)) {
1159 found = xfs_lookup_buffer_offset(page, &b_offset, type);
1162 * The found offset may be less than the start
1163 * point to search if this is the first time to
1166 *offset = max_t(loff_t, startoff, b_offset);
1172 * We either searching data but nothing was found, or
1173 * searching hole but found a data buffer. In either
1174 * case, probably the next page contains the desired
1175 * things, update the last offset to it so.
1177 lastoff = page_offset(page) + PAGE_SIZE;
1182 * The number of returned pages less than our desired, search
1183 * done. In this case, nothing was found for searching data,
1184 * but we found a hole behind the last offset.
1186 if (nr_pages < want) {
1187 if (type == HOLE_OFF) {
1194 index = pvec.pages[i - 1]->index + 1;
1195 pagevec_release(&pvec);
1196 } while (index <= end);
1199 pagevec_release(&pvec);
1208 struct inode *inode = file->f_mapping->host;
1209 struct xfs_inode *ip = XFS_I(inode);
1210 struct xfs_mount *mp = ip->i_mount;
1211 loff_t uninitialized_var(offset);
1213 xfs_fileoff_t fsbno;
1218 lock = xfs_ilock_data_map_shared(ip);
1220 isize = i_size_read(inode);
1221 if (start >= isize) {
1227 * Try to read extents from the first block indicated
1228 * by fsbno to the end block of the file.
1230 fsbno = XFS_B_TO_FSBT(mp, start);
1231 end = XFS_B_TO_FSB(mp, isize);
1233 struct xfs_bmbt_irec map[2];
1237 error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
1242 /* No extents at given offset, must be beyond EOF */
1248 for (i = 0; i < nmap; i++) {
1249 offset = max_t(loff_t, start,
1250 XFS_FSB_TO_B(mp, map[i].br_startoff));
1252 /* Landed in a data extent */
1253 if (map[i].br_startblock == DELAYSTARTBLOCK ||
1254 (map[i].br_state == XFS_EXT_NORM &&
1255 !isnullstartblock(map[i].br_startblock)))
1259 * Landed in an unwritten extent, try to search data
1262 if (map[i].br_state == XFS_EXT_UNWRITTEN) {
1263 if (xfs_find_get_desired_pgoff(inode, &map[i],
1270 * map[0] is hole or its an unwritten extent but
1271 * without data in page cache. Probably means that
1272 * we are reading after EOF if nothing in map[1].
1282 * Nothing was found, proceed to the next round of search
1283 * if reading offset not beyond or hit EOF.
1285 fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
1286 start = XFS_FSB_TO_B(mp, fsbno);
1287 if (start >= isize) {
1294 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1297 xfs_iunlock(ip, lock);
1309 struct inode *inode = file->f_mapping->host;
1310 struct xfs_inode *ip = XFS_I(inode);
1311 struct xfs_mount *mp = ip->i_mount;
1312 loff_t uninitialized_var(offset);
1314 xfs_fileoff_t fsbno;
1319 if (XFS_FORCED_SHUTDOWN(mp))
1320 return -XFS_ERROR(EIO);
1322 lock = xfs_ilock_data_map_shared(ip);
1324 isize = i_size_read(inode);
1325 if (start >= isize) {
1330 fsbno = XFS_B_TO_FSBT(mp, start);
1331 end = XFS_B_TO_FSB(mp, isize);
1334 struct xfs_bmbt_irec map[2];
1338 error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
1343 /* No extents at given offset, must be beyond EOF */
1349 for (i = 0; i < nmap; i++) {
1350 offset = max_t(loff_t, start,
1351 XFS_FSB_TO_B(mp, map[i].br_startoff));
1353 /* Landed in a hole */
1354 if (map[i].br_startblock == HOLESTARTBLOCK)
1358 * Landed in an unwritten extent, try to search hole
1361 if (map[i].br_state == XFS_EXT_UNWRITTEN) {
1362 if (xfs_find_get_desired_pgoff(inode, &map[i],
1369 * map[0] contains data or its unwritten but contains
1370 * data in page cache, probably means that we are
1371 * reading after EOF. We should fix offset to point
1372 * to the end of the file(i.e., there is an implicit
1373 * hole at the end of any file).
1383 * Both mappings contains data, proceed to the next round of
1384 * search if the current reading offset not beyond or hit EOF.
1386 fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
1387 start = XFS_FSB_TO_B(mp, fsbno);
1388 if (start >= isize) {
1396 * At this point, we must have found a hole. However, the returned
1397 * offset may be bigger than the file size as it may be aligned to
1398 * page boundary for unwritten extents, we need to deal with this
1399 * situation in particular.
1401 offset = min_t(loff_t, offset, isize);
1402 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1405 xfs_iunlock(ip, lock);
1422 return generic_file_llseek(file, offset, origin);
1424 return xfs_seek_data(file, offset);
1426 return xfs_seek_hole(file, offset);
1432 const struct file_operations xfs_file_operations = {
1433 .llseek = xfs_file_llseek,
1434 .read = do_sync_read,
1435 .write = do_sync_write,
1436 .aio_read = xfs_file_aio_read,
1437 .aio_write = xfs_file_aio_write,
1438 .splice_read = xfs_file_splice_read,
1439 .splice_write = xfs_file_splice_write,
1440 .unlocked_ioctl = xfs_file_ioctl,
1441 #ifdef CONFIG_COMPAT
1442 .compat_ioctl = xfs_file_compat_ioctl,
1444 .mmap = xfs_file_mmap,
1445 .open = xfs_file_open,
1446 .release = xfs_file_release,
1447 .fsync = xfs_file_fsync,
1448 .fallocate = xfs_file_fallocate,
1451 const struct file_operations xfs_dir_file_operations = {
1452 .open = xfs_dir_open,
1453 .read = generic_read_dir,
1454 .iterate = xfs_file_readdir,
1455 .llseek = generic_file_llseek,
1456 .unlocked_ioctl = xfs_file_ioctl,
1457 #ifdef CONFIG_COMPAT
1458 .compat_ioctl = xfs_file_compat_ioctl,
1460 .fsync = xfs_dir_fsync,
1463 static const struct vm_operations_struct xfs_file_vm_ops = {
1464 .fault = filemap_fault,
1465 .page_mkwrite = xfs_vm_page_mkwrite,
1466 .remap_pages = generic_file_remap_pages,