diff options
Diffstat (limited to 'linux-2.6-ext4-fix-freeze-deadlock.patch')
| -rw-r--r-- | linux-2.6-ext4-fix-freeze-deadlock.patch | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/linux-2.6-ext4-fix-freeze-deadlock.patch b/linux-2.6-ext4-fix-freeze-deadlock.patch new file mode 100644 index 000000000..e7eb817af --- /dev/null +++ b/linux-2.6-ext4-fix-freeze-deadlock.patch @@ -0,0 +1,46 @@ +[PATCH] ext4: fix freeze deadlock under IO + +Commit 6b0310fbf087ad6 caused a regression resulting in deadlocks +when freezing a filesystem which had active IO; the vfs_check_frozen +level (SB_FREEZE_WRITE) did not let the freeze-related IO syncing +through. Duh. + +Changing the test to FREEZE_TRANS should let the normal freeze +syncing get through the fs, but still block any transactions from +starting once the fs is completely frozen. + +I tested this by running fsstress in the background while periodically +snapshotting the fs and running fsck on the result. I ran into +occasional deadlocks, but different ones. I think this is a +fine fix for the problem at hand, and the other deadlocky things +will need more investigation. + +Reported-by: Phillip Susi <psusi@cfl.rr.com> +Signed-off-by: Eric Sandeen <sandeen@redhat.com> +--- + +diff --git a/fs/ext4/super.c b/fs/ext4/super.c +index 4e8983a..a45ced9 100644 +--- a/fs/ext4/super.c ++++ b/fs/ext4/super.c +@@ -241,7 +241,7 @@ handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks) + if (sb->s_flags & MS_RDONLY) + return ERR_PTR(-EROFS); + +- vfs_check_frozen(sb, SB_FREEZE_WRITE); ++ vfs_check_frozen(sb, SB_FREEZE_TRANS); + /* Special case here: if the journal has aborted behind our + * backs (eg. EIO in the commit thread), then we still need to + * take the FS itself readonly cleanly. */ +@@ -3491,7 +3491,7 @@ int ext4_force_commit(struct super_block *sb) + + journal = EXT4_SB(sb)->s_journal; + if (journal) { +- vfs_check_frozen(sb, SB_FREEZE_WRITE); ++ vfs_check_frozen(sb, SB_FREEZE_TRANS); + ret = ext4_journal_force_commit(journal); + } + + + + |