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authorDarrick J. Wong <darrick.wong@oracle.com>2018-07-19 12:29:13 -0700
committerDarrick J. Wong <darrick.wong@oracle.com>2018-07-23 09:08:01 -0700
commit2e9e6481e2a78de3a85083beccfbf6eda2689922 (patch)
tree0154cfaeb88ee991396b590707293c0d3de4befa /fs/xfs/libxfs
parent032d91f9820f6d241dc5584c27a668cfd377aaf0 (diff)
xfs: detect and fix bad summary counts at mount
Filippo Giunchedi complained that xfs doesn't even perform basic sanity checks of the fs summary counters at mount time. Therefore, recalculate the summary counters from the AGFs after log recovery if the counts were bad (or we had to recover the fs). Enhance the recalculation routine to fail the mount entirely if the new values are also obviously incorrect. We use a mount state flag to record the "bad summary count" state so that the (subsequent) online fsck patches can detect subtlely incorrect counts and set the flag; clear it userspace asks for a repair; or force a recalculation at the next mount if nobody fixes it by unmount time. Reported-by: Filippo Giunchedi <fgiunchedi@wikimedia.org> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/xfs/libxfs')
-rw-r--r--fs/xfs/libxfs/xfs_sb.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 350119eeaecb..b3ad15956366 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -804,6 +804,7 @@ xfs_initialize_perag_data(
uint64_t bfree = 0;
uint64_t bfreelst = 0;
uint64_t btree = 0;
+ uint64_t fdblocks;
int error;
for (index = 0; index < agcount; index++) {
@@ -827,17 +828,31 @@ xfs_initialize_perag_data(
btree += pag->pagf_btreeblks;
xfs_perag_put(pag);
}
+ fdblocks = bfree + bfreelst + btree;
+
+ /*
+ * If the new summary counts are obviously incorrect, fail the
+ * mount operation because that implies the AGFs are also corrupt.
+ * Clear BAD_SUMMARY so that we don't unmount with a dirty log, which
+ * will prevent xfs_repair from fixing anything.
+ */
+ if (fdblocks > sbp->sb_dblocks || ifree > ialloc) {
+ xfs_alert(mp, "AGF corruption. Please run xfs_repair.");
+ error = -EFSCORRUPTED;
+ goto out;
+ }
/* Overwrite incore superblock counters with just-read data */
spin_lock(&mp->m_sb_lock);
sbp->sb_ifree = ifree;
sbp->sb_icount = ialloc;
- sbp->sb_fdblocks = bfree + bfreelst + btree;
+ sbp->sb_fdblocks = fdblocks;
spin_unlock(&mp->m_sb_lock);
xfs_reinit_percpu_counters(mp);
-
- return 0;
+out:
+ mp->m_flags &= ~XFS_MOUNT_BAD_SUMMARY;
+ return error;
}
/*