diff options
author | Theodore Ts'o <tytso@mit.edu> | 2011-02-12 08:18:24 -0500 |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2011-02-12 08:18:24 -0500 |
commit | e44718318004a5618d1dfe2d080e2862532d8e5f (patch) | |
tree | c1a6af07da3184f5785a62062510ac8e86b8050a /fs/jbd2/transaction.c | |
parent | e9e3bcecf44c04b9e6b505fd8e2eb9cea58fb94d (diff) |
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 faad2bd787c..1d1191050f9 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) | |||
117 | static int start_this_handle(journal_t *journal, handle_t *handle, | 117 | static int start_this_handle(journal_t *journal, handle_t *handle, |
118 | int gfp_mask) | 118 | int gfp_mask) |
119 | { | 119 | { |
120 | transaction_t *transaction; | 120 | transaction_t *transaction, *new_transaction = NULL; |
121 | int needed; | 121 | tid_t tid; |
122 | int nblocks = handle->h_buffer_credits; | 122 | int needed, need_to_start; |
123 | transaction_t *new_transaction = NULL; | 123 | int nblocks = handle->h_buffer_credits; |
124 | 124 | ||
125 | if (nblocks > journal->j_max_transaction_buffers) { | 125 | if (nblocks > journal->j_max_transaction_buffers) { |
126 | printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", | 126 | printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", |
@@ -222,8 +222,11 @@ repeat: | |||
222 | atomic_sub(nblocks, &transaction->t_outstanding_credits); | 222 | atomic_sub(nblocks, &transaction->t_outstanding_credits); |
223 | prepare_to_wait(&journal->j_wait_transaction_locked, &wait, | 223 | prepare_to_wait(&journal->j_wait_transaction_locked, &wait, |
224 | TASK_UNINTERRUPTIBLE); | 224 | TASK_UNINTERRUPTIBLE); |
225 | __jbd2_log_start_commit(journal, transaction->t_tid); | 225 | tid = transaction->t_tid; |
226 | need_to_start = !tid_geq(journal->j_commit_request, tid); | ||
226 | read_unlock(&journal->j_state_lock); | 227 | read_unlock(&journal->j_state_lock); |
228 | if (need_to_start) | ||
229 | jbd2_log_start_commit(journal, tid); | ||
227 | schedule(); | 230 | schedule(); |
228 | finish_wait(&journal->j_wait_transaction_locked, &wait); | 231 | finish_wait(&journal->j_wait_transaction_locked, &wait); |
229 | goto repeat; | 232 | goto repeat; |
@@ -442,7 +445,8 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, int gfp_mask) | |||
442 | { | 445 | { |
443 | transaction_t *transaction = handle->h_transaction; | 446 | transaction_t *transaction = handle->h_transaction; |
444 | journal_t *journal = transaction->t_journal; | 447 | journal_t *journal = transaction->t_journal; |
445 | int ret; | 448 | tid_t tid; |
449 | int need_to_start, ret; | ||
446 | 450 | ||
447 | /* If we've had an abort of any type, don't even think about | 451 | /* If we've had an abort of any type, don't even think about |
448 | * actually doing the restart! */ | 452 | * actually doing the restart! */ |
@@ -465,8 +469,11 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, int gfp_mask) | |||
465 | spin_unlock(&transaction->t_handle_lock); | 469 | spin_unlock(&transaction->t_handle_lock); |
466 | 470 | ||
467 | jbd_debug(2, "restarting handle %p\n", handle); | 471 | jbd_debug(2, "restarting handle %p\n", handle); |
468 | __jbd2_log_start_commit(journal, transaction->t_tid); | 472 | tid = transaction->t_tid; |
473 | need_to_start = !tid_geq(journal->j_commit_request, tid); | ||
469 | read_unlock(&journal->j_state_lock); | 474 | read_unlock(&journal->j_state_lock); |
475 | if (need_to_start) | ||
476 | jbd2_log_start_commit(journal, tid); | ||
470 | 477 | ||
471 | lock_map_release(&handle->h_lockdep_map); | 478 | lock_map_release(&handle->h_lockdep_map); |
472 | handle->h_buffer_credits = nblocks; | 479 | handle->h_buffer_credits = nblocks; |