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| author | Eric Sandeen <sandeen@sandeen.net> | 2010-08-01 17:33:29 -0400 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2011-01-06 18:07:38 -0500 |
| commit | 963912d831b606ae776dfa7ef12ed26bfd0a6ee3 (patch) | |
| tree | 0ecf298ac7a90287cc20ae40982a2b1893b3d12f /fs | |
| parent | a17fa98c4c808a8ce7d7478a7a64e108c29ca1fe (diff) | |
| download | lwn-963912d831b606ae776dfa7ef12ed26bfd0a6ee3.tar.gz lwn-963912d831b606ae776dfa7ef12ed26bfd0a6ee3.zip | |
ext4: fix freeze deadlock under IO
commit 437f88cc031ffe7f37f3e705367f4fe1f4be8b0f upstream.
[The 6b0310fb below references the mainline version of what
has also been cherry picked into this 34-stable branch]
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>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/super.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 2aa9314ace85..cd35e34646e2 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. */ @@ -3485,7 +3485,7 @@ 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); } |