Re: [PATCH 2/3] ext3: Use WRITE_SYNC for commits which are caused by fsync()

Jan Kara
2009-03-27T22:20:33Z

On Fri 27-03-09 16:24:30, Theodore Ts'o wrote:
> If a commit is triggered by fsync(), set a flag indicating the journal
> blocks associated with the transaction should be flushed out using
> WRITE_SYNC.
>
> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
And this one seems fine as well. Acked-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/jbd/commit.c | 23 +++++++++++++++--------
> fs/jbd/transaction.c | 2 ++
> include/linux/jbd.h | 5 +++++
> 3 files changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
> index 3fbffb1..f8077b9 100644
> --- a/fs/jbd/commit.c
> +++ b/fs/jbd/commit.c
> @@ -20,6 +20,7 @@
> #include <linux/slab.h>
> #include <linux/mm.h>
> #include <linux/pagemap.h>
> +#include <linux/bio.h>
>
> /*
> * Default IO end handler for temporary BJ_IO buffer_heads.
> @@ -171,14 +172,15 @@ static int journal_write_commit_record(journal_t *journal,
> return (ret == -EIO);
> }
>
> -static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
> +static void journal_do_submit_data(struct buffer_head **wbuf, int bufs,
> + int write_op)
> {
> int i;
>
> for (i = 0; i < bufs; i++) {
> wbuf[i]->b_end_io = end_buffer_write_sync;
> /* We use-up our safety reference in submit_bh() */
> - submit_bh(WRITE, wbuf[i]);
> + submit_bh(write_op, wbuf[i]);
> }
> }
>
> @@ -186,7 +188,8 @@ static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
> * Submit all the data buffers to disk
> */
> static int journal_submit_data_buffers(journal_t *journal,
> - transaction_t *commit_transaction)
> + transaction_t *commit_transaction,
> + int write_op)
> {
> struct journal_head *jh;
> struct buffer_head *bh;
> @@ -225,7 +228,7 @@ write_out_data:
> BUFFER_TRACE(bh, "needs blocking lock");
> spin_unlock(&journal->j_list_lock);
> /* Write out all data to prevent deadlocks */
> - journal_do_submit_data(wbuf, bufs);
> + journal_do_submit_data(wbuf, bufs, write_op);
> bufs = 0;
> lock_buffer(bh);
> spin_lock(&journal->j_list_lock);
> @@ -256,7 +259,7 @@ write_out_data:
> jbd_unlock_bh_state(bh);
> if (bufs == journal->j_wbufsize) {
> spin_unlock(&journal->j_list_lock);
> - journal_do_submit_data(wbuf, bufs);
> + journal_do_submit_data(wbuf, bufs, write_op);
> bufs = 0;
> goto write_out_data;
> }
> @@ -286,7 +289,7 @@ write_out_data:
> }
> }
> spin_unlock(&journal->j_list_lock);
> - journal_do_submit_data(wbuf, bufs);
> + journal_do_submit_data(wbuf, bufs, write_op);
>
> return err;
> }
> @@ -315,6 +318,7 @@ void journal_commit_transaction(journal_t *journal)
> int first_tag = 0;
> int tag_flag;
> int i;
> + int write_op = WRITE;
>
> /*
> * First job: lock down the current transaction and wait for
> @@ -347,6 +351,8 @@ void journal_commit_transaction(journal_t *journal)
> spin_lock(&journal->j_state_lock);
> commit_transaction->t_state = T_LOCKED;
>
> + if (commit_transaction->t_synchronous_commit)
> + write_op = WRITE_SYNC;
> spin_lock(&commit_transaction->t_handle_lock);
> while (commit_transaction->t_updates) {
> DEFINE_WAIT(wait);
> @@ -431,7 +437,8 @@ void journal_commit_transaction(journal_t *journal)
> * Now start flushing things to disk, in the order they appear
> * on the transaction lists. Data blocks go first.
> */
> - err = journal_submit_data_buffers(journal, commit_transaction);
> + err = journal_submit_data_buffers(journal, commit_transaction,
> + write_op);
>
> /*
> * Wait for all previously submitted IO to complete.
> @@ -660,7 +667,7 @@ start_journal_io:
> clear_buffer_dirty(bh);
> set_buffer_uptodate(bh);
> bh->b_end_io = journal_end_buffer_io_sync;
> - submit_bh(WRITE, bh);
> + submit_bh(write_op, bh);
> }
> cond_resched();
>
> diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
> index e6a1174..ed886e6 100644
> --- a/fs/jbd/transaction.c
> +++ b/fs/jbd/transaction.c
> @@ -1440,6 +1440,8 @@ int journal_stop(handle_t *handle)
> }
> }
>
> + if (handle->h_sync)
> + transaction->t_synchronous_commit = 1;
> current->journal_info = NULL;
> spin_lock(&journal->j_state_lock);
> spin_lock(&transaction->t_handle_lock);
> diff --git a/include/linux/jbd.h b/include/linux/jbd.h
> index 64246dc..2c69431 100644
> --- a/include/linux/jbd.h
> +++ b/include/linux/jbd.h
> @@ -552,6 +552,11 @@ struct transaction_s
> */
> int t_handle_count;
>
> + /*
> + * This transaction is being forced and some process is
> + * waiting for it to finish.
> + */
> + int t_synchronous_commit:1;
> };
>
> /**
> --
> 1.5.6.3
>
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR