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| author | Theodore Ts'o <tytso@mit.edu> | 2011-02-12 14:18:24 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-02-12 14:18:24 +0100 |
| commit | e44718318004a5618d1dfe2d080e2862532d8e5f (patch) | |
| tree | c1a6af07da3184f5785a62062510ac8e86b8050a /fs/jbd2/transaction.c | |
| parent | ext4: serialize unaligned asynchronous DIO (diff) | |
| download | linux-e44718318004a5618d1dfe2d080e2862532d8e5f.tar.xz linux-e44718318004a5618d1dfe2d080e2862532d8e5f.zip | |
jbd2: call __jbd2_log_start_commit with j_state_lock write locked
On an SMP ARM system running ext4, I've received a report that the
first J_ASSERT in jbd2_journal_commit_transaction has been triggering:
J_ASSERT(journal->j_running_transaction != NULL);
While investigating possible causes for this problem, I noticed that
__jbd2_log_start_commit() is getting called with j_state_lock only
read-locked, in spite of the fact that it's possible for it might
j_commit_request. Fix this by grabbing the necessary information so
we can test to see if we need to start a new transaction before
dropping the read lock, and then calling jbd2_log_start_commit() which
will grab the write lock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2/transaction.c')
| -rw-r--r-- | fs/jbd2/transaction.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index faad2bd787c7..1d1191050f99 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -117,10 +117,10 @@ static inline void update_t_max_wait(transaction_t *transaction) static int start_this_handle(journal_t *journal, handle_t *handle, int gfp_mask) { - transaction_t *transaction; - int needed; - int nblocks = handle->h_buffer_credits; - transaction_t *new_transaction = NULL; + transaction_t *transaction, *new_transaction = NULL; + tid_t tid; + int needed, need_to_start; + int nblocks = handle->h_buffer_credits; if (nblocks > journal->j_max_transaction_buffers) { printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", @@ -222,8 +222,11 @@ repeat: atomic_sub(nblocks, &transaction->t_outstanding_credits); prepare_to_wait(&journal->j_wait_transaction_locked, &wait, TASK_UNINTERRUPTIBLE); - __jbd2_log_start_commit(journal, transaction->t_tid); + tid = transaction->t_tid; + need_to_start = !tid_geq(journal->j_commit_request, tid); read_unlock(&journal->j_state_lock); + if (need_to_start) + jbd2_log_start_commit(journal, tid); schedule(); finish_wait(&journal->j_wait_transaction_locked, &wait); goto repeat; @@ -442,7 +445,8 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, int gfp_mask) { transaction_t *transaction = handle->h_transaction; journal_t *journal = transaction->t_journal; - int ret; + tid_t tid; + int need_to_start, ret; /* If we've had an abort of any type, don't even think about * actually doing the restart! */ @@ -465,8 +469,11 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, int gfp_mask) spin_unlock(&transaction->t_handle_lock); jbd_debug(2, "restarting handle %p\n", handle); - __jbd2_log_start_commit(journal, transaction->t_tid); + tid = transaction->t_tid; + need_to_start = !tid_geq(journal->j_commit_request, tid); read_unlock(&journal->j_state_lock); + if (need_to_start) + jbd2_log_start_commit(journal, tid); lock_map_release(&handle->h_lockdep_map); handle->h_buffer_credits = nblocks; |