Message ID | 1409624051-6902-2-git-send-email-tytso@mit.edu |
---|---|
State | Accepted, archived |
Headers | show |
On Mon 01-09-14 22:14:11, Ted Tso wrote: > __wait_cp_io() is only called by jbd2_log_do_checkpoint(). Fold it in > to make it a bit easier to understand. > > Signed-off-by: Theodore Ts'o <tytso@mit.edu> Hum, is this really such a win? Unlike __process_buffer(), this function is well separated so IMHO the code is better readable before the folding. Honza > --- > fs/jbd2/checkpoint.c | 87 +++++++++++++++++++--------------------------------- > 1 file changed, 31 insertions(+), 56 deletions(-) > > diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c > index 993a187..22fcd50 100644 > --- a/fs/jbd2/checkpoint.c > +++ b/fs/jbd2/checkpoint.c > @@ -183,58 +183,6 @@ void __jbd2_log_wait_for_space(journal_t *journal) > } > } > > -/* > - * Clean up transaction's list of buffers submitted for io. > - * We wait for any pending IO to complete and remove any clean > - * buffers. Note that we take the buffers in the opposite ordering > - * from the one in which they were submitted for IO. > - * > - * Return 0 on success, and return <0 if some buffers have failed > - * to be written out. > - * > - * Called with j_list_lock held. > - */ > -static int __wait_cp_io(journal_t *journal, transaction_t *transaction) > -{ > - struct journal_head *jh; > - struct buffer_head *bh; > - tid_t this_tid; > - int released = 0; > - int ret = 0; > - > - this_tid = transaction->t_tid; > -restart: > - /* Did somebody clean up the transaction in the meanwhile? */ > - if (journal->j_checkpoint_transactions != transaction || > - transaction->t_tid != this_tid) > - return ret; > - while (!released && transaction->t_checkpoint_io_list) { > - jh = transaction->t_checkpoint_io_list; > - bh = jh2bh(jh); > - get_bh(bh); > - if (buffer_locked(bh)) { > - spin_unlock(&journal->j_list_lock); > - wait_on_buffer(bh); > - /* the journal_head may have gone by now */ > - BUFFER_TRACE(bh, "brelse"); > - __brelse(bh); > - spin_lock(&journal->j_list_lock); > - goto restart; > - } > - if (unlikely(buffer_write_io_error(bh))) > - ret = -EIO; > - > - /* > - * Now in whatever state the buffer currently is, we know that > - * it has been written out and so we can drop it from the list > - */ > - released = __jbd2_journal_remove_checkpoint(jh); > - __brelse(bh); > - } > - > - return ret; > -} > - > static void > __flush_batch(journal_t *journal, int *batch_count) > { > @@ -268,7 +216,7 @@ int jbd2_log_do_checkpoint(journal_t *journal) > struct buffer_head *bh; > transaction_t *transaction; > tid_t this_tid; > - int err, result, batch_count = 0; > + int result, batch_count = 0, done = 0; > > jbd_debug(1, "Start checkpoint\n"); > > @@ -384,9 +332,36 @@ restart: > * Now we issued all of the transaction's buffers, let's deal > * with the buffers that are out for I/O. > */ > - err = __wait_cp_io(journal, transaction); > - if (!result) > - result = err; > +restart2: > + /* Did somebody clean up the transaction in the meanwhile? */ > + if (journal->j_checkpoint_transactions != transaction || > + transaction->t_tid != this_tid) > + goto out; > + > + while (!done && transaction->t_checkpoint_io_list) { > + jh = transaction->t_checkpoint_io_list; > + bh = jh2bh(jh); > + get_bh(bh); > + if (buffer_locked(bh)) { > + spin_unlock(&journal->j_list_lock); > + wait_on_buffer(bh); > + /* the journal_head may have gone by now */ > + BUFFER_TRACE(bh, "brelse"); > + __brelse(bh); > + spin_lock(&journal->j_list_lock); > + goto restart2; > + } > + if (unlikely(buffer_write_io_error(bh)) && !result) > + result = -EIO; > + > + /* > + * Now in whatever state the buffer currently is, we > + * know that it has been written out and so we can > + * drop it from the list > + */ > + done = __jbd2_journal_remove_checkpoint(jh); > + __brelse(bh); > + } > out: > spin_unlock(&journal->j_list_lock); > if (result < 0) > -- > 2.1.0 > > -- > 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 Tue, Sep 02, 2014 at 06:30:33PM +0200, Jan Kara wrote: > Hum, is this really such a win? Unlike __process_buffer(), this function > is well separated so IMHO the code is better readable before the folding. I agree it's a closer call. I'm not wedded to folding in __wait_cp_io. I was reacting more to the fact that the comment right before the call to __wait_cp_io was horribly misleading, and when I looked to confirm what I thought __wait_cp_io() was doing, it looked like another static function used in exactly one place that could be folded in. If other folks think that it's more readable w/o this patch, I'm happy to drop it. Anyone else have an opinion? Cheers, - 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/checkpoint.c b/fs/jbd2/checkpoint.c index 993a187..22fcd50 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -183,58 +183,6 @@ void __jbd2_log_wait_for_space(journal_t *journal) } } -/* - * Clean up transaction's list of buffers submitted for io. - * We wait for any pending IO to complete and remove any clean - * buffers. Note that we take the buffers in the opposite ordering - * from the one in which they were submitted for IO. - * - * Return 0 on success, and return <0 if some buffers have failed - * to be written out. - * - * Called with j_list_lock held. - */ -static int __wait_cp_io(journal_t *journal, transaction_t *transaction) -{ - struct journal_head *jh; - struct buffer_head *bh; - tid_t this_tid; - int released = 0; - int ret = 0; - - this_tid = transaction->t_tid; -restart: - /* Did somebody clean up the transaction in the meanwhile? */ - if (journal->j_checkpoint_transactions != transaction || - transaction->t_tid != this_tid) - return ret; - while (!released && transaction->t_checkpoint_io_list) { - jh = transaction->t_checkpoint_io_list; - bh = jh2bh(jh); - get_bh(bh); - if (buffer_locked(bh)) { - spin_unlock(&journal->j_list_lock); - wait_on_buffer(bh); - /* the journal_head may have gone by now */ - BUFFER_TRACE(bh, "brelse"); - __brelse(bh); - spin_lock(&journal->j_list_lock); - goto restart; - } - if (unlikely(buffer_write_io_error(bh))) - ret = -EIO; - - /* - * Now in whatever state the buffer currently is, we know that - * it has been written out and so we can drop it from the list - */ - released = __jbd2_journal_remove_checkpoint(jh); - __brelse(bh); - } - - return ret; -} - static void __flush_batch(journal_t *journal, int *batch_count) { @@ -268,7 +216,7 @@ int jbd2_log_do_checkpoint(journal_t *journal) struct buffer_head *bh; transaction_t *transaction; tid_t this_tid; - int err, result, batch_count = 0; + int result, batch_count = 0, done = 0; jbd_debug(1, "Start checkpoint\n"); @@ -384,9 +332,36 @@ restart: * Now we issued all of the transaction's buffers, let's deal * with the buffers that are out for I/O. */ - err = __wait_cp_io(journal, transaction); - if (!result) - result = err; +restart2: + /* Did somebody clean up the transaction in the meanwhile? */ + if (journal->j_checkpoint_transactions != transaction || + transaction->t_tid != this_tid) + goto out; + + while (!done && transaction->t_checkpoint_io_list) { + jh = transaction->t_checkpoint_io_list; + bh = jh2bh(jh); + get_bh(bh); + if (buffer_locked(bh)) { + spin_unlock(&journal->j_list_lock); + wait_on_buffer(bh); + /* the journal_head may have gone by now */ + BUFFER_TRACE(bh, "brelse"); + __brelse(bh); + spin_lock(&journal->j_list_lock); + goto restart2; + } + if (unlikely(buffer_write_io_error(bh)) && !result) + result = -EIO; + + /* + * Now in whatever state the buffer currently is, we + * know that it has been written out and so we can + * drop it from the list + */ + done = __jbd2_journal_remove_checkpoint(jh); + __brelse(bh); + } out: spin_unlock(&journal->j_list_lock); if (result < 0)
__wait_cp_io() is only called by jbd2_log_do_checkpoint(). Fold it in to make it a bit easier to understand. Signed-off-by: Theodore Ts'o <tytso@mit.edu> --- fs/jbd2/checkpoint.c | 87 +++++++++++++++++++--------------------------------- 1 file changed, 31 insertions(+), 56 deletions(-)