| Message ID | 20191003220613.10791-13-jack@suse.cz |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ext4: Fix transaction overflow due to revoke descriptors | expand |
On Fri, Oct 04, 2019 at 12:05:59AM +0200, Jan Kara wrote: > If a transaction is larger than journal->j_max_transaction_buffers, that > is a bug and not a trigger for transaction commit. Also the very next > attempt to start new handle will start transaction commit anyway. So > just remove the pointless check. Arguably, we could start transaction > commit whenever the transaction size is *close* to > journal->j_max_transaction_buffers. This has a potential to reduce > latency of the next jbd2_journal_start() at the cost of somewhat smaller > transactions. However for this to have any effect, it would mean that > there isn't someone already waiting in jbd2_journal_start() which means > metadata load for the fs is pretty light anyway so probably this > optimization is not worth it. > > Signed-off-by: Jan Kara <jack@suse.cz> Looks good; feel free to add: Reviewed-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index 6f560713f7f0..a160c3f665f9 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1803,13 +1803,10 @@ int jbd2_journal_stop(handle_t *handle) /* * If the handle is marked SYNC, we need to set another commit - * going! We also want to force a commit if the current - * transaction is occupying too much of the log, or if the - * transaction is too old now. + * going! We also want to force a commit if the transaction is too + * old now. */ if (handle->h_sync || - (atomic_read(&transaction->t_outstanding_credits) > - journal->j_max_transaction_buffers) || time_after_eq(jiffies, transaction->t_expires)) { /* Do this even for aborted journals: an abort still * completes the commit thread, it just doesn't write
If a transaction is larger than journal->j_max_transaction_buffers, that is a bug and not a trigger for transaction commit. Also the very next attempt to start new handle will start transaction commit anyway. So just remove the pointless check. Arguably, we could start transaction commit whenever the transaction size is *close* to journal->j_max_transaction_buffers. This has a potential to reduce latency of the next jbd2_journal_start() at the cost of somewhat smaller transactions. However for this to have any effect, it would mean that there isn't someone already waiting in jbd2_journal_start() which means metadata load for the fs is pretty light anyway so probably this optimization is not worth it. Signed-off-by: Jan Kara <jack@suse.cz> --- fs/jbd2/transaction.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)