diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-09 12:51:21 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-09 12:51:21 -0800 |
commit | ac69e0928054ff29a5049902fb477f9c7605c773 (patch) | |
tree | 05be6b9285186823452e0adeffe40e1dfee6e354 /fs/jbd/transaction.c | |
parent | 9e203936eac786f9268d6a13e6442d2accef1829 (diff) | |
parent | 302bf2f3259948c93361d501b04a5ed69c3bd4f8 (diff) |
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext2/3/4: delete unneeded includes of module.h
ext{3,4}: Fix potential race when setversion ioctl updates inode
udf: Mark LVID buffer as uptodate before marking it dirty
ext3: Don't warn from writepage when readonly inode is spotted after error
jbd: Remove j_barrier mutex
reiserfs: Force inode evictions before umount to avoid crash
reiserfs: Fix quota mount option parsing
udf: Treat symlink component of type 2 as /
udf: Fix deadlock when converting file from in-ICB one to normal one
udf: Cleanup calling convention of inode_getblk()
ext2: Fix error handling on inode bitmap corruption
ext3: Fix error handling on inode bitmap corruption
ext3: replace ll_rw_block with other functions
ext3: NULL dereference in ext3_evict_inode()
jbd: clear revoked flag on buffers before a new transaction started
ext3: call ext3_mark_recovery_complete() when recovery is really needed
Diffstat (limited to 'fs/jbd/transaction.c')
-rw-r--r-- | fs/jbd/transaction.c | 38 |
1 files changed, 22 insertions, 16 deletions
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c index 7e59c6e66f9b..7fce94b04bc3 100644 --- a/fs/jbd/transaction.c +++ b/fs/jbd/transaction.c @@ -426,17 +426,34 @@ int journal_restart(handle_t *handle, int nblocks) * void journal_lock_updates () - establish a transaction barrier. * @journal: Journal to establish a barrier on. * - * This locks out any further updates from being started, and blocks - * until all existing updates have completed, returning only once the - * journal is in a quiescent state with no updates running. - * - * The journal lock should not be held on entry. + * This locks out any further updates from being started, and blocks until all + * existing updates have completed, returning only once the journal is in a + * quiescent state with no updates running. + * + * We do not use simple mutex for synchronization as there are syscalls which + * want to return with filesystem locked and that trips up lockdep. Also + * hibernate needs to lock filesystem but locked mutex then blocks hibernation. + * Since locking filesystem is rare operation, we use simple counter and + * waitqueue for locking. */ void journal_lock_updates(journal_t *journal) { DEFINE_WAIT(wait); +wait: + /* Wait for previous locked operation to finish */ + wait_event(journal->j_wait_transaction_locked, + journal->j_barrier_count == 0); + spin_lock(&journal->j_state_lock); + /* + * Check reliably under the lock whether we are the ones winning the race + * and locking the journal + */ + if (journal->j_barrier_count > 0) { + spin_unlock(&journal->j_state_lock); + goto wait; + } ++journal->j_barrier_count; /* Wait until there are no running updates */ @@ -460,14 +477,6 @@ void journal_lock_updates(journal_t *journal) spin_lock(&journal->j_state_lock); } spin_unlock(&journal->j_state_lock); - - /* - * We have now established a barrier against other normal updates, but - * we also need to barrier against other journal_lock_updates() calls - * to make sure that we serialise special journal-locked operations - * too. - */ - mutex_lock(&journal->j_barrier); } /** @@ -475,14 +484,11 @@ void journal_lock_updates(journal_t *journal) * @journal: Journal to release the barrier on. * * Release a transaction barrier obtained with journal_lock_updates(). - * - * Should be called without the journal lock held. */ void journal_unlock_updates (journal_t *journal) { J_ASSERT(journal->j_barrier_count != 0); - mutex_unlock(&journal->j_barrier); spin_lock(&journal->j_state_lock); --journal->j_barrier_count; spin_unlock(&journal->j_state_lock); |