Jan Kara b5f0e25121 jbd2: fix assertion failure in jbd2_journal_flush() ... commit d7961c7fa4 upstream. The following race is possible between start_this_handle() and someone calling jbd2_journal_flush(). Process A Process B start_this_handle(). if (journal->j_barrier_count) # false if (!journal->j_running_transaction) { #true read_unlock(&journal->j_state_lock); jbd2_journal_lock_updates() jbd2_journal_flush() write_lock(&journal->j_state_lock); if (journal->j_running_transaction) { # false ... wait for committing trans ... write_unlock(&journal->j_state_lock); ... write_lock(&journal->j_state_lock); if (!journal->j_running_transaction) { # true jbd2_get_transaction(journal, new_transaction); write_unlock(&journal->j_state_lock); goto repeat; # eventually blocks on j_barrier_count > 0 ... J_ASSERT(!journal->j_running_transaction); # fails We fix the race by rechecking j_barrier_count after reacquiring j_state_lock in exclusive mode. Reported-by: yjwsignal@empal.com Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2013-01-17 08:50:52 -08:00
..
checkpoint.c	jbd2: remove bh_state lock from checkpointing code	2012-03-13 22:45:25 -04:00
commit.c	jbd2: use GFP_NOFS for blkdev_issue_flush	2012-04-23 21:43:41 -04:00
journal.c	jbd2: don't write superblock when if its empty	2012-10-13 05:38:39 +09:00
Kconfig	Revert "task_struct: make journal_info conditional"	2009-12-17 13:23:24 -08:00
Makefile
recovery.c	jbd2: issue cache flush after checkpointing even with internal journal	2012-03-13 22:22:54 -04:00
revoke.c	jbd2: use KMEM_CACHE instead of kmem_cache_create()	2012-02-20 17:53:03 -05:00
transaction.c	jbd2: fix assertion failure in jbd2_journal_flush()	2013-01-17 08:50:52 -08:00