Patch "xfs: fix log block underflow during recovery cycle verification" has been added to the 4.14-stable tree
Subsystems (2)
This is a note to let you know that I've just added the patch titled
xfs: fix log block underflow during recovery cycle verification
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xfs-fix-log-block-underflow-during-recovery-cycle-verification.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From foo@baz Mon Dec 18 13:28:59 CET 2017
From: Brian Foster <[email protected]>
Date: Thu, 26 Oct 2017 09:31:16 -0700
Subject: xfs: fix log block underflow during recovery cycle verification
From: Brian Foster <[email protected]>
[ Upstream commit 9f2a4505800607e537e9dd9dea4f55c4b0c30c7a ]
It is possible for mkfs to format very small filesystems with too small of an internal log with respect to the various minimum size and block count requirements. If this occurs when the log happens to be smaller than the scan window used for cycle verification and the scan wraps the end of the log, the start_blk calculation in xlog_find_head() underflows and leads to an attempt to scan an invalid range of log blocks. This results in log recovery failure and a failed mount.
Since there may be filesystems out in the wild with this kind of geometry, we cannot simply refuse to mount. Instead, cap the scan window for cycle verification to the size of the physical log. This ensures that the cycle verification proceeds as expected when the scan wraps the end of the log.
--- fs/xfs/xfs_log_recover.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
fs/xfs/xfs_log_recover.c +1 -1
@@ -753,7 +753,7 @@ xlog_find_head(* in the in-core log. The following number can be made tighter if * we actually look at the block size of the filesystem. */ - num_scan_bblks =XLOG_TOTAL_REC_SHIFT (log); + num_scan_bblks =min_t (int, log_bbnum,XLOG_TOTAL_REC_SHIFT (log));if (head_blk >= num_scan_bblks) {/* * We are guaranteed that the entire check can be performed
Patches currently in stable-queue which might be from [email protected] are
queue-4.14/xfs-fix-incorrect-extent-state-in-xfs_bmap_add_extent_unwritten_real.patch queue-4.14/xfs-fix-log-block-underflow-during-recovery-cycle-verification.patch queue-4.14/xfs-truncate-pagecache-before-writeback-in-xfs_setattr_size.patch queue-4.14/xfs-return-a-distinct-error-code-value-for-iget_incore-cache-misses.patch