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authorEric Sandeen <sandeen@redhat.com>2010-05-30 22:49:50 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-02 10:21:19 -0700
commite6afda19e101a5c85eb43ec49f00b8336002f2cd (patch)
treea62e5199ecf24331698639be519d20316aff3c86
parentad86a2309c447ebd7fb238f6bafb268e6b7e95b5 (diff)
ext4: don't return to userspace after freezing the fs with a mutex held
commit 6b0310fbf087ad6e9e3b8392adca97cd77184084 upstream (as of v2.6.34-git13) 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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-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 252f30b6bb61..d85549c210fe 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -227,6 +227,7 @@ 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. */
@@ -3391,8 +3392,10 @@ 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;
}
@@ -3441,18 +3444,16 @@ 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;
}
/*
@@ -3469,7 +3470,6 @@ 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;
}