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2ebff7bbd7
kernel-ark/fs/xfs
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Dave Chinner 2ebff7bbd7 xfs: flush entire last page of old EOF on truncate up 
On a sub-page sized filesystem, truncating a mapped region down
leaves us in a world of hurt. We truncate the pagecache, zeroing the
newly unused tail, then punch blocks out from under the page. If we
then truncate the file back up immediately, we expose that unmapped
hole to a dirty page mapped into the user application, and that's
where it all goes wrong.

In truncating the page cache, we avoid unmapping the tail page of
the cache because it still contains valid data. The problem is that
it also contains a hole after the truncate, but nobody told the mm
subsystem that. Therefore, if the page is dirty before the truncate,
we'll never get a .page_mkwrite callout after we extend the file and
the application writes data into the hole on the page.  Hence when
we come to writing that region of the page, it has no blocks and no
delayed allocation reservation and hence we toss the data away.

This patch adds code to the truncate up case to solve it, by
ensuring the partial page at the old EOF is always cleaned after we
do any zeroing and move the EOF upwards. We can't actually serialise
the page writeback and truncate against page faults (yes, that
problem AGAIN) so this is really just a best effort and assumes it
is extremely unlikely that someone is concurrently writing to the
page at the EOF while extending the file.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-23 22:55:00 +10:00
..
libxfs xfs: don't ASSERT on corrupt ftype 2014-09-23 16:05:32 +10:00
Kconfig xfs: require 64-bit sector_t 2014-07-30 09:12:05 +10:00
kmem.c xfs: use NOIO contexts for vm_map_ram 2014-03-07 16:19:14 +11:00
kmem.h xfs: simplify kmem_{zone_}zalloc 2013-11-06 16:31:27 -06:00
Makefile xfs: add xfs_mount sysfs kobject 2014-07-15 08:07:01 +10:00
mrlock.h xfs: introduce CONFIG_XFS_WARN 2013-05-07 18:45:36 -05:00
time.h
uuid.c
uuid.h xfs: add CRC infrastructure 2012-11-19 20:11:24 -06:00
xfs_acl.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_acl.h xfs: use generic posix ACL infrastructure 2014-01-25 23:58:21 -05:00
xfs_aops.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_aops.h direct-io: Implement generic deferred AIO completions 2013-09-04 09:23:46 -04:00
xfs_attr_inactive.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_attr_list.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_attr.h xfs: kill xfs_vnodeops.[ch] 2013-08-12 16:53:39 -05:00
xfs_bit.c xfs: fix static and extern sparse warnings 2013-10-30 13:59:56 -05:00
xfs_bmap_util.c xfs: xfs_swap_extent_flush can be static 2014-09-23 16:20:11 +10:00
xfs_bmap_util.h xfs: refine the allocation stack switch 2014-07-15 07:08:24 +10:00
xfs_buf_item.c xfs: xfs_buf_write_fail_rl_state can be static 2014-09-23 16:15:45 +10:00
xfs_buf_item.h xfs: decouple inode and bmap btree header files 2013-10-23 16:28:49 -05:00
xfs_buf.c xfs: mark all internal workqueues as freezable 2014-09-09 11:44:46 +10:00
xfs_buf.h xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_dir2_readdir.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_discard.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_discard.h
xfs_dquot_item.c xfs: remove the quotaoff log format from the quotaoff log item 2013-12-13 11:34:08 +11:00
xfs_dquot_item.h xfs: remove the quotaoff log format from the quotaoff log item 2013-12-13 11:34:08 +11:00
xfs_dquot.c xfs: quotacheck leaves dquot buffers without verifiers 2014-08-04 12:43:26 +10:00
xfs_dquot.h xfs: run an eofblocks scan on ENOSPC/EDQUOT 2014-07-24 19:49:28 +10:00
xfs_error.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_error.h xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_export.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_export.h
xfs_extent_busy.c xfs: decouple inode and bmap btree header files 2013-10-23 16:28:49 -05:00
xfs_extent_busy.h xfs: decouple inode and bmap btree header files 2013-10-23 16:28:49 -05:00
xfs_extfree_item.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_extfree_item.h xfs: split out EFI/EFD log item format definition 2013-08-12 16:07:13 -05:00
xfs_file.c xfs: lseek: the "whence" argument is called "whence" 2014-09-09 11:57:10 +10:00
xfs_filestream.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_filestream.h xfs: add filestream allocator tracepoints 2014-04-23 07:11:52 +10:00
xfs_fs.h Merge branch 'xfs-misc-fixes-3.17-1' into for-next 2014-08-04 13:54:14 +10:00
xfs_fsops.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_fsops.h
xfs_globals.c xfs: export log_recovery_delay to delay mount time log recovery 2014-09-09 11:56:13 +10:00
xfs_icache.c xfs: remove second xfs_quota.h inclusion in xfs_icache.c 2014-09-23 16:05:55 +10:00
xfs_icache.h xfs: run an eofblocks scan on ENOSPC/EDQUOT 2014-07-24 19:49:28 +10:00
xfs_icreate_item.c xfs: format log items write directly into the linear CIL buffer 2013-12-13 11:34:02 +11:00
xfs_icreate_item.h xfs: separate icreate log format definitions from xfs_icreate_item.h 2013-08-12 16:10:35 -05:00
xfs_inode_item.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_inode_item.h xfs: remove the inode log format from the inode log item 2013-12-13 11:34:05 +11:00
xfs_inode.c xfs: check resblks before calling xfs_dir_canenter 2014-09-09 11:57:52 +10:00
xfs_inode.h xfs: kill xfs_vnode.h 2014-08-04 13:28:20 +10:00
xfs_ioctl32.c Merge branch 'xfs-misc-fixes-3.17-2' into for-next 2014-08-04 13:55:27 +10:00
xfs_ioctl32.h
xfs_ioctl.c Merge branch 'xfs-misc-fixes-3.17-2' into for-next 2014-08-04 13:55:27 +10:00
xfs_ioctl.h xfs: consolidate extent swap code 2013-08-12 16:56:06 -05:00
xfs_iomap.c Merge branch 'xfs-quota-eofblocks-scan' into for-next 2014-08-04 13:53:47 +10:00
xfs_iomap.h xfs: get rid of count from xfs_iomap_write_allocate() 2013-10-01 15:42:34 -05:00
xfs_iops.c xfs: flush entire last page of old EOF on truncate up 2014-09-23 22:55:00 +10:00
xfs_iops.h xfs: use generic posix ACL infrastructure 2014-01-25 23:58:21 -05:00
xfs_itable.c xfs: introduce xfs_bulkstat_ag_ichunk 2014-08-04 11:22:31 +10:00
xfs_itable.h xfs: introduce xfs_bulkstat_ag_ichunk 2014-08-04 11:22:31 +10:00
xfs_linux.h Merge branch 'xfs-misc-fixes-3.17-2' into for-next 2014-08-04 13:55:27 +10:00
xfs_log_cil.c xfs: xlog_cil_force_lsn doesn't always wait correctly 2014-09-23 15:57:59 +10:00
xfs_log_priv.h xfs: add xlog sysfs kobject and attribute handlers 2014-07-15 08:07:29 +10:00
xfs_log_recover.c xfs: deduplicate xlog_do_recovery_pass() 2014-09-09 11:57:29 +10:00
xfs_log.c Merge branch 'xfs-misc-fixes-3.17-2' into for-next 2014-08-04 13:55:27 +10:00
xfs_log.h xfs: log vector rounding leaks log space 2014-05-20 08:18:09 +10:00
xfs_message.c xfs: decouple log and transaction headers 2013-10-23 16:17:44 -05:00
xfs_message.h xfs: introduce CONFIG_XFS_WARN 2013-05-07 18:45:36 -05:00
xfs_mount.c Merge branch 'xfs-misc-fixes-3.17-2' into for-next 2014-08-04 13:55:27 +10:00
xfs_mount.h xfs: add xfs_mount sysfs kobject 2014-07-15 08:07:01 +10:00
xfs_mru_cache.c xfs: mark all internal workqueues as freezable 2014-09-09 11:44:46 +10:00
xfs_mru_cache.h xfs: embedd mru_elem into parent structure 2014-04-23 07:11:51 +10:00
xfs_qm_bhv.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_qm_syscalls.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_qm.c Merge branch 'xfs-misc-fixes-3.17-2' into for-next 2014-08-04 13:55:27 +10:00
xfs_qm.h xfs: mark xfs_qm_quotacheck as static 2014-07-24 20:49:57 +10:00
xfs_quota.h xfs: split dquot buffer operations out 2013-10-23 14:28:35 -05:00
xfs_quotaops.c xfs: fix uflags detection at xfs_fs_rm_xquota 2014-07-24 21:27:17 +10:00
xfs_rtalloc.c xfs: xfs_rtget_summary can be static 2014-09-23 16:11:43 +10:00
xfs_rtalloc.h xfs: combine xfs_rtmodify_summary and xfs_rtget_summary 2014-09-09 11:58:42 +10:00
xfs_stats.c xfs: support the XFS_BTNUM_FINOBT free inode btree type 2014-04-24 16:00:52 +10:00
xfs_stats.h xfs: support the XFS_BTNUM_FINOBT free inode btree type 2014-04-24 16:00:52 +10:00
xfs_super.c xfs: add debug sysfs attribute set 2014-09-09 11:52:42 +10:00
xfs_super.h xfs: require 64-bit sector_t 2014-07-30 09:12:05 +10:00
xfs_symlink.c xfs: check resblks before calling xfs_dir_canenter 2014-09-09 11:57:52 +10:00
xfs_symlink.h xfs: push down inactive transaction mgmt for remote symlinks 2013-10-08 14:53:02 -05:00
xfs_sysctl.c xfs: Convert use of typedef ctl_table to struct ctl_table 2013-06-17 17:42:25 -05:00
xfs_sysctl.h xfs: export log_recovery_delay to delay mount time log recovery 2014-09-09 11:56:13 +10:00
xfs_sysfs.c xfs: export log_recovery_delay to delay mount time log recovery 2014-09-09 11:56:13 +10:00
xfs_sysfs.h xfs: add debug sysfs attribute set 2014-09-09 11:52:42 +10:00
xfs_trace.c xfs: add filestream allocator tracepoints 2014-04-23 07:11:52 +10:00
xfs_trace.h Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
xfs_trans_ail.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_trans_buf.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_trans_dquot.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_trans_extfree.c xfs: decouple log and transaction headers 2013-10-23 16:17:44 -05:00
xfs_trans_inode.c xfs: open code inc_inode_iversion when logging an inode 2013-11-18 09:42:08 -06:00
xfs_trans_priv.h xfs: remove unused ail pointer arg from xfs_trans_ail_cursor_done() 2014-04-14 19:06:05 +10:00
xfs_trans.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_trans.h xfs: format log items write directly into the linear CIL buffer 2013-12-13 11:34:02 +11:00
xfs_types.h xfs: require 64-bit sector_t 2014-07-30 09:12:05 +10:00
xfs_xattr.c xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs.h xfs: introduce CONFIG_XFS_WARN 2013-05-07 18:45:36 -05:00