linux/fs/jbd
Jan Kara d4beaf4ab5 jbd: Fix assertion failure in fs/jbd/checkpoint.c
Before we start committing a transaction, we call
__journal_clean_checkpoint_list() to cleanup transaction's written-back
buffers.

If this call happens to remove all of them (and there were already some
buffers), __journal_remove_checkpoint() will decide to free the transaction
because it isn't (yet) a committing transaction and soon we fail some
assertion - the transaction really isn't ready to be freed :).

We change the check in __journal_remove_checkpoint() to free only a
transaction in T_FINISHED state.  The locking there is subtle though (as
everywhere in JBD ;().  We use j_list_lock to protect the check and a
subsequent call to __journal_drop_transaction() and do the same in the end
of journal_commit_transaction() which is the only place where a transaction
can get to T_FINISHED state.

Probably I'm too paranoid here and such locking is not really necessary -
checkpoint lists are processed only from log_do_checkpoint() where a
transaction must be already committed to be processed or from
__journal_clean_checkpoint_list() where kjournald itself calls it and thus
transaction cannot change state either.  Better be safe if something
changes in future...

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 09:21:20 -08:00
..
checkpoint.c jbd: Fix assertion failure in fs/jbd/checkpoint.c 2007-12-05 09:21:20 -08:00
commit.c jbd: Fix assertion failure in fs/jbd/checkpoint.c 2007-12-05 09:21:20 -08:00
journal.c jbd: config_jbd_debug cannot create /proc entry 2007-10-19 11:53:35 -07:00
Makefile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
recovery.c JBD: Fix JBD warnings when compiling with CONFIG_JBD_DEBUG 2007-10-19 11:53:35 -07:00
revoke.c Group short-lived and reclaimable kernel allocations 2007-10-16 09:43:00 -07:00
transaction.c JBD/ext3 cleanups: convert to kzalloc 2007-10-19 11:53:34 -07:00