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Groups > linux.kernel > #1733866
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 4.13 47/52] xfs: fix incorrect log_flushed on fsync |
| Date | 2017-09-18 11:20 +0200 |
| Message-ID | <ur0nL-4ck-183@gated-at.bofh.it> (permalink) |
| References | <ur0nE-4ck-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
4.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Amir Goldstein <amir73il@gmail.com>
commit 47c7d0b19502583120c3f396c7559e7a77288a68 upstream.
When calling into _xfs_log_force{,_lsn}() with a pointer
to log_flushed variable, log_flushed will be set to 1 if:
1. xlog_sync() is called to flush the active log buffer
AND/OR
2. xlog_wait() is called to wait on a syncing log buffers
xfs_file_fsync() checks the value of log_flushed after
_xfs_log_force_lsn() call to optimize away an explicit
PREFLUSH request to the data block device after writing
out all the file's pages to disk.
This optimization is incorrect in the following sequence of events:
Task A Task B
-------------------------------------------------------
xfs_file_fsync()
_xfs_log_force_lsn()
xlog_sync()
[submit PREFLUSH]
xfs_file_fsync()
file_write_and_wait_range()
[submit WRITE X]
[endio WRITE X]
_xfs_log_force_lsn()
xlog_wait()
[endio PREFLUSH]
The write X is not guarantied to be on persistent storage
when PREFLUSH request in completed, because write A was submitted
after the PREFLUSH request, but xfs_file_fsync() of task A will
be notified of log_flushed=1 and will skip explicit flush.
If the system crashes after fsync of task A, write X may not be
present on disk after reboot.
This bug was discovered and demonstrated using Josef Bacik's
dm-log-writes target, which can be used to record block io operations
and then replay a subset of these operations onto the target device.
The test goes something like this:
- Use fsx to execute ops of a file and record ops on log device
- Every now and then fsync the file, store md5 of file and mark
the location in the log
- Then replay log onto device for each mark, mount fs and compare
md5 of file to stored value
Cc: Christoph Hellwig <hch@lst.de>
Cc: Josef Bacik <jbacik@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/xfs/xfs_log.c | 7 -------
1 file changed, 7 deletions(-)
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -3375,8 +3375,6 @@ maybe_sleep:
*/
if (iclog->ic_state & XLOG_STATE_IOERROR)
return -EIO;
- if (log_flushed)
- *log_flushed = 1;
} else {
no_sleep:
@@ -3480,8 +3478,6 @@ try_again:
xlog_wait(&iclog->ic_prev->ic_write_wait,
&log->l_icloglock);
- if (log_flushed)
- *log_flushed = 1;
already_slept = 1;
goto try_again;
}
@@ -3515,9 +3511,6 @@ try_again:
*/
if (iclog->ic_state & XLOG_STATE_IOERROR)
return -EIO;
-
- if (log_flushed)
- *log_flushed = 1;
} else { /* just return */
spin_unlock(&log->l_icloglock);
}
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[PATCH 4.13 00/52] 4.13.3-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 14/52] thunderbolt: Remove superfluous check Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 16/52] thunderbolt: Allow clearing the key Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 30/52] xfs: fix recovery failure when log record header wraps log end Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 04/52] vhost_net: correctly check tx avail during rx busy polling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 20/52] x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 35/52] xfs: evict all inodes involved with log redo item Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 21/52] ovl: fix false positive ESTALE on lookup Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 37/52] xfs: open-code xfs_buf_item_dirty() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 11/52] ip_tunnel: fix setting ttl and tos value in collect_md mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 01/52] Revert "net: use lib/percpu_counter API for fragmentation mem accounting" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 12/52] f2fs: let fill_super handle roll-forward errors Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 15/52] thunderbolt: Make key root-only accessible Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 47/52] xfs: fix incorrect log_flushed on fsync Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 40/52] xfs: refactor buffer logging into buffer dirtying helper Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 52/52] md/raid5: release/flush io in raid5_do_work() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 11:20 +0200
[PATCH 4.13 08/52] ipv6: fix typo in fib6_net_exit() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 50/52] xfs: use kmem_free to free return value of kmem_zalloc Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 28/52] xfs: Add infrastructure needed for error propagation during buffer IO failure Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 24/52] libnvdimm, btt: check memory allocation failure Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 38/52] xfs: remove unnecessary dirty bli format check for ordered bufs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 46/52] xfs: disable per-inode DAX flag Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 23/52] idr: remove WARN_ON_ONCE() when trying to replace negative ID Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 31/52] xfs: always verify the log tail during recovery Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 41/52] xfs: dont log dirty ranges for ordered buffers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 43/52] xfs: move bmbt owner change to last step of extent swap Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 48/52] xfs: dont set v3 xflags for v2 inodes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 13/52] f2fs: check hot_data for roll-forward recovery Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 33/52] xfs: handle -EFSCORRUPTED during head/tail verification Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 39/52] xfs: ordered buffer log items are never formatted Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 10/52] tcp: fix a request socket leak Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 34/52] xfs: stop searching for free slots in an inode chunk when there are none Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 09/52] sctp: fix missing wake ups in some situations Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 42/52] xfs: skip bmbt block ino validation during owner change Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 51/52] md/raid1/10: reset bio allocated from mempool Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 36/52] xfs: check for race with xfs_reclaim_inode() in xfs_ifree_cluster() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 25/52] libnvdimm: fix integer overflow static analysis warning Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 32/52] xfs: fix log recovery corruption error due to tail overwrite Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 29/52] xfs: Properly retry failed inode items in case of error during buffer writeback Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:00 +0200
[PATCH 4.13 03/52] gianfar: Fix Tx flow control deactivation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:10 +0200
[PATCH 4.13 02/52] Revert "net: fix percpu memory leaks" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:10 +0200
[PATCH 4.13 17/52] x86/fsgsbase/64: Fully initialize FS and GS state in start_thread_common Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:10 +0200
[PATCH 4.13 06/52] udp: drop head states only when all skb references are gone Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-18 12:10 +0200
Re: [PATCH 4.13 00/52] 4.13.3-stable review Guenter Roeck <linux@roeck-us.net> - 2017-09-18 21:30 +0200
Re: [PATCH 4.13 00/52] 4.13.3-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-09-18 22:20 +0200
Re: [PATCH 4.13 00/52] 4.13.3-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-19 08:40 +0200
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