| Message ID | 20111226101727.1ca09119.toshi.okajima@jp.fujitsu.com |
|---|---|
| State | New, archived |
| Headers | show |
Looks good to me. Thanks, Yongqiang. On Mon, Dec 26, 2011 at 9:17 AM, Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> wrote: > Delete all spin_lock(t_handle_lock) statements inside write_lock(j_state_lock) > because the critical code sections can be protected by write_lock(j_state_lock) > only. > > Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> > Reported-by: Yongqiang Yang <xiaoqiangnk@gmail.com> > --- > fs/jbd2/commit.c | 4 ---- > fs/jbd2/transaction.c | 6 +----- > 2 files changed, 1 insertions(+), 9 deletions(-) > > diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c > index 68d704d..1030d47 100644 > --- a/fs/jbd2/commit.c > +++ b/fs/jbd2/commit.c > @@ -364,22 +364,18 @@ void jbd2_journal_commit_transaction(journal_t *journal) > stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start, > stats.run.rs_locked); > > - spin_lock(&commit_transaction->t_handle_lock); > while (atomic_read(&commit_transaction->t_updates)) { > DEFINE_WAIT(wait); > > prepare_to_wait(&journal->j_wait_updates, &wait, > TASK_UNINTERRUPTIBLE); > if (atomic_read(&commit_transaction->t_updates)) { > - spin_unlock(&commit_transaction->t_handle_lock); > write_unlock(&journal->j_state_lock); > schedule(); > write_lock(&journal->j_state_lock); > - spin_lock(&commit_transaction->t_handle_lock); > } > finish_wait(&journal->j_wait_updates, &wait); > } > - spin_unlock(&commit_transaction->t_handle_lock); > > J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <= > journal->j_max_transaction_buffers); > diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c > index 76f2eca..c418ed9 100644 > --- a/fs/jbd2/transaction.c > +++ b/fs/jbd2/transaction.c > @@ -516,14 +516,10 @@ void jbd2_journal_lock_updates(journal_t *journal) > if (!transaction) > break; > > - spin_lock(&transaction->t_handle_lock); > - if (!atomic_read(&transaction->t_updates)) { > - spin_unlock(&transaction->t_handle_lock); > + if (!atomic_read(&transaction->t_updates)) > break; > - } > prepare_to_wait(&journal->j_wait_updates, &wait, > TASK_UNINTERRUPTIBLE); > - spin_unlock(&transaction->t_handle_lock); > write_unlock(&journal->j_state_lock); > schedule(); > finish_wait(&journal->j_wait_updates, &wait); > -- > 1.5.5.6
On Mon 26-12-11 10:17:27, Toshiyuki Okajima wrote: > Delete all spin_lock(t_handle_lock) statements inside write_lock(j_state_lock) > because the critical code sections can be protected by write_lock(j_state_lock) > only. > > Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> > Reported-by: Yongqiang Yang <xiaoqiangnk@gmail.com> The patch looks good. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/jbd2/commit.c | 4 ---- > fs/jbd2/transaction.c | 6 +----- > 2 files changed, 1 insertions(+), 9 deletions(-) > > diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c > index 68d704d..1030d47 100644 > --- a/fs/jbd2/commit.c > +++ b/fs/jbd2/commit.c > @@ -364,22 +364,18 @@ void jbd2_journal_commit_transaction(journal_t *journal) > stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start, > stats.run.rs_locked); > > - spin_lock(&commit_transaction->t_handle_lock); > while (atomic_read(&commit_transaction->t_updates)) { > DEFINE_WAIT(wait); > > prepare_to_wait(&journal->j_wait_updates, &wait, > TASK_UNINTERRUPTIBLE); > if (atomic_read(&commit_transaction->t_updates)) { > - spin_unlock(&commit_transaction->t_handle_lock); > write_unlock(&journal->j_state_lock); > schedule(); > write_lock(&journal->j_state_lock); > - spin_lock(&commit_transaction->t_handle_lock); > } > finish_wait(&journal->j_wait_updates, &wait); > } > - spin_unlock(&commit_transaction->t_handle_lock); > > J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <= > journal->j_max_transaction_buffers); > diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c > index 76f2eca..c418ed9 100644 > --- a/fs/jbd2/transaction.c > +++ b/fs/jbd2/transaction.c > @@ -516,14 +516,10 @@ void jbd2_journal_lock_updates(journal_t *journal) > if (!transaction) > break; > > - spin_lock(&transaction->t_handle_lock); > - if (!atomic_read(&transaction->t_updates)) { > - spin_unlock(&transaction->t_handle_lock); > + if (!atomic_read(&transaction->t_updates)) > break; > - } > prepare_to_wait(&journal->j_wait_updates, &wait, > TASK_UNINTERRUPTIBLE); > - spin_unlock(&transaction->t_handle_lock); > write_unlock(&journal->j_state_lock); > schedule(); > finish_wait(&journal->j_wait_updates, &wait); > -- > 1.5.5.6 > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Dec 26, 2011 at 10:17:27AM +0900, Toshiyuki Okajima wrote: > Delete all spin_lock(t_handle_lock) statements inside write_lock(j_state_lock) > because the critical code sections can be protected by write_lock(j_state_lock) > only. > > Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> > Reported-by: Yongqiang Yang <xiaoqiangnk@gmail.com> This may be true today, but I'm worried this is going to make the code more fragile. The header file include/linux/jbd2.h defines which fields are protected by which lock. This patch is going to make those comments partially obsolete. We need to make sure the locking protocol is clearly defined before we go around removing locks. This is something I would like to do, but we need to make sure the code remains maintainable in the long run. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 68d704d..1030d47 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -364,22 +364,18 @@ void jbd2_journal_commit_transaction(journal_t *journal) stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start, stats.run.rs_locked); - spin_lock(&commit_transaction->t_handle_lock); while (atomic_read(&commit_transaction->t_updates)) { DEFINE_WAIT(wait); prepare_to_wait(&journal->j_wait_updates, &wait, TASK_UNINTERRUPTIBLE); if (atomic_read(&commit_transaction->t_updates)) { - spin_unlock(&commit_transaction->t_handle_lock); write_unlock(&journal->j_state_lock); schedule(); write_lock(&journal->j_state_lock); - spin_lock(&commit_transaction->t_handle_lock); } finish_wait(&journal->j_wait_updates, &wait); } - spin_unlock(&commit_transaction->t_handle_lock); J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <= journal->j_max_transaction_buffers); diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index 76f2eca..c418ed9 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -516,14 +516,10 @@ void jbd2_journal_lock_updates(journal_t *journal) if (!transaction) break; - spin_lock(&transaction->t_handle_lock); - if (!atomic_read(&transaction->t_updates)) { - spin_unlock(&transaction->t_handle_lock); + if (!atomic_read(&transaction->t_updates)) break; - } prepare_to_wait(&journal->j_wait_updates, &wait, TASK_UNINTERRUPTIBLE); - spin_unlock(&transaction->t_handle_lock); write_unlock(&journal->j_state_lock); schedule(); finish_wait(&journal->j_wait_updates, &wait);
Delete all spin_lock(t_handle_lock) statements inside write_lock(j_state_lock) because the critical code sections can be protected by write_lock(j_state_lock) only. Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Reported-by: Yongqiang Yang <xiaoqiangnk@gmail.com> --- fs/jbd2/commit.c | 4 ---- fs/jbd2/transaction.c | 6 +----- 2 files changed, 1 insertions(+), 9 deletions(-)