Theodore Ts'o 15f26a4c48 jbd2: fix theoretical race in jbd2__journal_restart ... commit 39c04153fda8c32e85b51c96eb5511a326ad7609 upstream. Once we decrement transaction->t_updates, if this is the last handle holding the transaction from closing, and once we release the t_handle_lock spinlock, it's possible for the transaction to commit and be released. In practice with normal kernels, this probably won't happen, since the commit happens in a separate kernel thread and it's unlikely this could all happen within the space of a few CPU cycles. On the other hand, with a real-time kernel, this could potentially happen, so save the tid found in transaction->t_tid before we release t_handle_lock. It would require an insane configuration, such as one where the jbd2 thread was set to a very high real-time priority, perhaps because a high priority real-time thread is trying to read or write to a file system. But some people who use real-time kernels have been known to do insane things, including controlling laser-wielding industrial robots. :-) Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2013-07-21 18:21:22 -07:00
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checkpoint.c
commit.c	jbd2: fix race between jbd2_journal_remove_checkpoint and ->j_commit_callback	2013-04-03 22:06:52 -04:00
journal.c	jbd2: move superblock checksum calculation to jbd2_write_superblock()	2013-07-21 18:21:22 -07:00
Kconfig
Makefile
recovery.c
revoke.c
transaction.c	jbd2: fix theoretical race in jbd2__journal_restart	2013-07-21 18:21:22 -07:00