linux/fs/xfs
Eryu Guan 350976ae21 xfs: truncate pagecache before writeback in xfs_setattr_size()
On truncate down, if new size is not block size aligned, we zero the
rest of block to avoid exposing stale data to user, and
iomap_truncate_page() skips zeroing if the range is already in
unwritten state or a hole. Then we writeback from on-disk i_size to
the new size if this range hasn't been written to disk yet, and
truncate page cache beyond new EOF and set in-core i_size.

The problem is that we could write data between di_size and newsize
before removing the page cache beyond newsize, as the extents may
still be in unwritten state right after a buffer write. As such, the
page of data that newsize lies in has not been zeroed by page cache
invalidation before it is written, and xfs_do_writepage() hasn't
triggered it's "zero data beyond EOF" case because we haven't
updated in-core i_size yet. Then a subsequent mmap read could see
non-zeros past EOF.

I occasionally see this in fsx runs in fstests generic/112, a
simplified fsx operation sequence is like (assuming 4k block size
xfs):

  fallocate 0x0 0x1000 0x0 keep_size
  write 0x0 0x1000 0x0
  truncate 0x0 0x800 0x1000
  punch_hole 0x0 0x800 0x800
  mapread 0x0 0x800 0x800

where fallocate allocates unwritten extent but doesn't update
i_size, buffer write populates the page cache and extent is still
unwritten, truncate skips zeroing page past new EOF and writes the
page to disk, punch_hole invalidates the page cache, at last mapread
reads the block back and sees non-zero beyond EOF.

Fix it by moving truncate_setsize() to before writeback so the page
cache invalidation zeros the partial page at the new EOF. This also
triggers "zero data beyond EOF" in xfs_do_writepage() at writeback
time, because newsize has been set and page straddles the newsize.

Also fixed the wrong 'end' param of filemap_write_and_wait_range()
call while we're at it, the 'end' is inclusive and should be
'newsize - 1'.

Suggested-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-03 09:45:56 -07:00
..
libxfs xfs: convert remaining xfs_sb_version_... checks to bool 2017-11-01 15:03:16 -07:00
scrub xfs: scrub extended attribute leaf space 2017-11-01 15:03:16 -07:00
Kconfig xfs: create an ioctl to scrub AG metadata 2017-10-26 15:38:23 -07:00
kmem.c mm, vmalloc: use __GFP_HIGHMEM implicitly 2017-05-08 17:15:13 -07:00
kmem.h xfs: map KM_MAYFAIL to __GFP_RETRY_MAYFAIL 2017-07-12 16:26:03 -07:00
Makefile xfs: scrub quota information 2017-10-26 15:38:26 -07:00
mrlock.h
xfs_acl.c xfs: don't change inode mode if ACL update fails 2017-10-11 10:21:06 -07:00
xfs_acl.h xfs: Don't clear SGID when inheriting ACLs 2017-06-27 18:23:21 -07:00
xfs_aops.c xfs: trim writepage mapping to within eof 2017-10-16 12:26:50 -07:00
xfs_aops.h xfs: perform dax_device lookup at mount 2017-08-31 09:31:47 -07:00
xfs_attr_inactive.c xfs: fail if xattr inactivation hits a hole 2017-10-26 15:38:22 -07:00
xfs_attr_list.c xfs: abort dir/attr btree operation if btree is obviously weird 2017-10-27 09:20:31 -07:00
xfs_attr.h xfs: scrub extended attributes 2017-10-26 15:38:26 -07:00
xfs_bmap_item.c xfs: remove the ip argument to xfs_defer_finish 2017-09-01 10:55:30 -07:00
xfs_bmap_item.h xfs: log bmap intent items 2016-10-04 11:05:44 -07:00
xfs_bmap_util.c xfs: add asserts for the mmap lock in xfs_{insert,collapse}_file_space 2017-10-26 15:38:28 -07:00
xfs_bmap_util.h xfs: simplify the xfs_getbmap interface 2017-10-26 15:38:20 -07:00
xfs_buf_item.c xfs: fix compiler warnings 2017-09-02 08:22:19 -07:00
xfs_buf_item.h xfs: remove unnecessary dirty bli format check for ordered bufs 2017-09-01 10:55:30 -07:00
xfs_buf.c xfs: move error injection tags into their own file 2017-11-01 15:03:16 -07:00
xfs_buf.h xfs: buffer lru reference count error injection tag 2017-10-26 15:38:23 -07:00
xfs_dir2_readdir.c xfs: scrub directory metadata 2017-10-26 15:38:25 -07:00
xfs_discard.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_discard.h xfs: don't block the log commit handler for discards 2017-02-09 11:36:40 -08:00
xfs_dquot_item.c xfs: allocate log vector buffers outside CIL context lock 2016-07-22 09:52:35 +10:00
xfs_dquot_item.h
xfs_dquot.c xfs: remove the ip argument to xfs_defer_finish 2017-09-01 10:55:30 -07:00
xfs_dquot.h
xfs_error.c xfs: move error injection tags into their own file 2017-11-01 15:03:16 -07:00
xfs_error.h xfs: move error injection tags into their own file 2017-11-01 15:03:16 -07:00
xfs_export.c xfs: abstract block export operations from nfsd layouts 2016-07-15 15:31:29 -04:00
xfs_export.h
xfs_extent_busy.c xfs: fix len comparison in xfs_extent_busy_trim 2017-02-16 17:20:12 -08:00
xfs_extent_busy.h xfs: improve handling of busy extents in the low-level allocator 2017-02-09 10:50:25 -08:00
xfs_extfree_item.c xfs: better log intent item refcount checking 2017-04-25 09:40:42 -07:00
xfs_extfree_item.h xfs: refactor redo intent item processing 2016-08-03 11:23:49 +10:00
xfs_file.c xfs: scrub directory metadata 2017-10-26 15:38:25 -07:00
xfs_filestream.c Merge branch 'xfs-4.9-log-recovery-fixes' into for-next 2016-10-03 09:56:28 +11:00
xfs_filestream.h
xfs_fsmap.c xfs: move two more RT specific functions into CONFIG_XFS_RT 2017-10-16 12:26:50 -07:00
xfs_fsmap.h xfs: implement the GETFSMAP ioctl 2017-04-03 15:18:17 -07:00
xfs_fsops.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_fsops.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_globals.c xfs: define fatal assert build time tunable 2017-06-19 08:59:10 -07:00
xfs_icache.c xfs: return a distinct error code value for IGET_INCORE cache misses 2017-10-26 15:38:23 -07:00
xfs_icache.h xfs: check if an inode is cached and allocated 2017-06-19 14:11:34 -07:00
xfs_icreate_item.c fs: xfs: xfs_icreate_item: constify xfs_item_ops structure 2016-11-28 14:57:42 +11:00
xfs_icreate_item.h
xfs_inode_item.c xfs: remove if_rdev 2017-10-26 15:38:27 -07:00
xfs_inode_item.h xfs: remove inode log format typedef 2017-11-01 15:03:16 -07:00
xfs_inode.c xfs: move error injection tags into their own file 2017-11-01 15:03:16 -07:00
xfs_inode.h xfs: remove if_rdev 2017-10-26 15:38:27 -07:00
xfs_ioctl32.c xfs: create an ioctl to scrub AG metadata 2017-10-26 15:38:23 -07:00
xfs_ioctl32.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_ioctl.c xfs: scrub inodes 2017-10-26 15:38:25 -07:00
xfs_ioctl.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_iomap.c xfs: move error injection tags into their own file 2017-11-01 15:03:16 -07:00
xfs_iomap.h xfs: update i_size after unwritten conversion in dio completion 2017-09-26 10:55:19 -07:00
xfs_iops.c xfs: truncate pagecache before writeback in xfs_setattr_size() 2017-11-03 09:45:56 -07:00
xfs_iops.h xfs: Propagate dentry down to inode_change_ok() 2016-09-22 10:56:19 +02:00
xfs_itable.c xfs: remove if_rdev 2017-10-26 15:38:27 -07:00
xfs_itable.h xfs: create inode pointer verifiers 2017-10-26 15:38:23 -07:00
xfs_linux.h xfs: refactor btree block header checking functions 2017-10-26 15:38:23 -07:00
xfs_log_cil.c xfs: Fix leak of discard bio 2017-08-04 13:43:36 -07:00
xfs_log_priv.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_log_recover.c xfs: remove inode log format typedef 2017-11-01 15:03:16 -07:00
xfs_log.c xfs: move error injection tags into their own file 2017-11-01 15:03:16 -07:00
xfs_log.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_message.c xfs: define bug_on_assert debug mode sysfs tunable 2017-06-19 08:59:10 -07:00
xfs_message.h
xfs_mount.c xfs: Fix bool initialization/comparison 2017-10-11 10:21:06 -07:00
xfs_mount.h xfs: convert drop_writes to use the errortag mechanism 2017-06-27 18:23:20 -07:00
xfs_mru_cache.c
xfs_mru_cache.h
xfs_ondisk.h xfs: Don't log uninitialised fields in inode structures 2017-10-11 10:21:06 -07:00
xfs_pnfs.c xfs: update i_size after unwritten conversion in dio completion 2017-09-26 10:55:19 -07:00
xfs_pnfs.h xfs: remove i_iolock and use i_rwsem in the VFS inode instead 2016-11-30 14:33:25 +11:00
xfs_qm_bhv.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_qm_syscalls.c xfs: wait on new inodes during quotaoff dquot release 2017-04-28 08:11:08 -07:00
xfs_qm.c xfs: replace xfs_qm_get_rtblks with a direct call to xfs_bmap_count_leaves 2017-09-01 13:08:26 -07:00
xfs_qm.h
xfs_quota.h
xfs_quotaops.c VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) 2017-07-17 08:45:34 +01:00
xfs_refcount_item.c xfs: remove the ip argument to xfs_defer_finish 2017-09-01 10:55:30 -07:00
xfs_refcount_item.h xfs: log refcount intent items 2016-10-03 09:11:21 -07:00
xfs_reflink.c xfs: add a new xfs_iext_lookup_extent_before helper 2017-10-26 15:38:28 -07:00
xfs_reflink.h xfs: separate function to check if inode shares extents 2017-06-19 14:11:35 -07:00
xfs_rmap_item.c xfs: better log intent item refcount checking 2017-04-25 09:40:42 -07:00
xfs_rmap_item.h xfs: convert RUI log formats to use variable length arrays 2016-09-19 10:24:27 +10:00
xfs_rtalloc.c xfs: remove the ip argument to xfs_defer_finish 2017-09-01 10:55:30 -07:00
xfs_rtalloc.h xfs: create block pointer check functions 2017-10-26 15:38:23 -07:00
xfs_stats.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_stats.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_super.c Convert fs/*/* to SB_I_VERSION 2017-10-18 18:51:27 -04:00
xfs_super.h xfs: don't block the log commit handler for discards 2017-02-09 11:36:40 -08:00
xfs_symlink.c xfs: remove the ip argument to xfs_defer_finish 2017-09-01 10:55:30 -07:00
xfs_symlink.h xfs: allow reading of already-locked remote symbolic link 2017-06-20 10:45:22 -07:00
xfs_sysctl.c xfs: garbage collect old cowextsz reservations 2016-10-05 16:26:28 -07:00
xfs_sysctl.h xfs: define bug_on_assert debug mode sysfs tunable 2017-06-19 08:59:10 -07:00
xfs_sysfs.c xfs: replace log_badcrc_factor knob with error injection tag 2017-06-27 18:23:21 -07:00
xfs_sysfs.h xfs: configurable error behavior via sysfs 2016-05-18 10:58:51 +10:00
xfs_trace.c xfs: implement the GETFSMAP ioctl 2017-04-03 15:18:17 -07:00
xfs_trace.h xfs: remove XFS_BMAP_TRACE_EXLIST 2017-10-26 15:38:27 -07:00
xfs_trans_ail.c xfs: move error injection tags into their own file 2017-11-01 15:03:16 -07:00
xfs_trans_bmap.c xfs: try to avoid blowing out the transaction reservation when bunmaping a shared extent 2017-06-19 08:59:10 -07:00
xfs_trans_buf.c xfs: disallow marking previously dirty buffers as ordered 2017-09-01 10:55:30 -07:00
xfs_trans_dquot.c
xfs_trans_extfree.c xfs: set up per-AG free space reservations 2016-09-19 10:30:52 +10:00
xfs_trans_inode.c xfs: refactor xfs_trans_roll 2017-09-01 10:55:30 -07:00
xfs_trans_priv.h xfs: Properly retry failed inode items in case of error during buffer writeback 2017-08-22 09:22:23 -07:00
xfs_trans_refcount.c xfs: connect refcount adjust functions to upper layers 2016-10-03 09:11:22 -07:00
xfs_trans_rmap.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_trans.c xfs: refactor xfs_trans_roll 2017-09-01 10:55:30 -07:00
xfs_trans.h xfs: disallow marking previously dirty buffers as ordered 2017-09-01 10:55:30 -07:00
xfs_xattr.c xfs: several xattr functions can be void 2016-12-05 12:32:14 +11:00
xfs.h xfs: define fatal assert build time tunable 2017-06-19 08:59:10 -07:00