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authorEric Sandeen <sandeen@redhat.com>2010-05-16 02:00:00 -0400
committerTheodore Ts'o <tytso@mit.edu>2010-05-16 02:00:00 -0400
commit6b0310fbf087ad6e9e3b8392adca97cd77184084 (patch)
tree6c15fad6ca442d92e8075578a9b04811ca093bda /fs/ext4
parent256a453546f1cf2c29a639c79fe0d603761a8e25 (diff)
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ext4: don't return to userspace after freezing the fs with a mutex held
ext4_freeze() used jbd2_journal_lock_updates() which takes the j_barrier mutex, and then returns to userspace. The kernel does not like this: ================================================ [ BUG: lock held when returning to user space! ] ------------------------------------------------ lvcreate/1075 is leaving the kernel with locks still held! 1 lock held by lvcreate/1075: #0: (&journal->j_barrier){+.+...}, at: [<ffffffff811c6214>] jbd2_journal_lock_updates+0xe1/0xf0 Use vfs_check_frozen() added to ext4_journal_start_sb() and ext4_force_commit() instead. Addresses-Red-Hat-Bugzilla: #568503 Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/super.c20
1 files changed, 10 insertions, 10 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index e14d22c170d5..00d09f58f188 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -241,6 +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);
/* 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. */
@@ -3485,8 +3486,10 @@ int ext4_force_commit(struct super_block *sb)
return 0;
journal = EXT4_SB(sb)->s_journal;
- if (journal)
+ if (journal) {
+ vfs_check_frozen(sb, SB_FREEZE_WRITE);
ret = ext4_journal_force_commit(journal);
+ }
return ret;
}
@@ -3535,18 +3538,16 @@ static int ext4_freeze(struct super_block *sb)
* the journal.
*/
error = jbd2_journal_flush(journal);
- if (error < 0) {
- out:
- jbd2_journal_unlock_updates(journal);
- return error;
- }
+ if (error < 0)
+ goto out;
/* Journal blocked and flushed, clear needs_recovery flag. */
EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
error = ext4_commit_super(sb, 1);
- if (error)
- goto out;
- return 0;
+out:
+ /* we rely on s_frozen to stop further updates */
+ jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
+ return error;
}
/*
@@ -3563,7 +3564,6 @@ static int ext4_unfreeze(struct super_block *sb)
EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
ext4_commit_super(sb, 1);
unlock_super(sb);
- jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
return 0;
}