diff options
| author | Eric Sandeen <sandeen@redhat.com> | 2010-05-30 22:49:50 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-02 10:21:19 -0700 |
| commit | e6afda19e101a5c85eb43ec49f00b8336002f2cd (patch) | |
| tree | a62e5199ecf24331698639be519d20316aff3c86 | |
| parent | ad86a2309c447ebd7fb238f6bafb268e6b7e95b5 (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.c | 20 |
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; } |