>From 5674f84e70db8274d5aac56a41439ea3b3bcb46e Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Wed, 19 Jan 2011 13:45:04 +0100
Subject: [PATCH 1/2] jbd2: Refine commit writeout logic
Currently we write out all journal buffers in WRITE_SYNC mode. This improves
performance for fsync heavy workloads but hinders performance when writes
are mostly asynchronous. So add possibility for callers starting a transaction
commit to specify whether they are going to wait for the commit and submit
journal writes in WRITE_SYNC mode only in that case.
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/fsync.c | 2 +-
fs/ext4/super.c | 2 +-
fs/jbd2/checkpoint.c | 2 +-
fs/jbd2/commit.c | 4 ++--
fs/jbd2/journal.c | 19 ++++++++++---------
fs/jbd2/transaction.c | 13 ++++++-------
fs/ocfs2/aops.c | 2 +-
fs/ocfs2/super.c | 2 +-
include/linux/jbd2.h | 18 ++++++++++--------
9 files changed, 33 insertions(+), 31 deletions(-)
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 7829b28..19434da 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -198,7 +198,7 @@ int ext4_sync_file(struct file *file, int datasync)
return ext4_force_commit(inode->i_sb);
commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
- if (jbd2_log_start_commit(journal, commit_tid)) {
+ if (jbd2_log_start_commit(journal, commit_tid, true)) {
/*
* When the journal is on a different device than the
* fs data disk, we need to issue the barrier in
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 48ce561..0aeb877 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4113,7 +4113,7 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
trace_ext4_sync_fs(sb, wait);
flush_workqueue(sbi->dio_unwritten_wq);
- if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
+ if (jbd2_journal_start_commit(sbi->s_journal, &target, true)) {
if (wait)
jbd2_log_wait_commit(sbi->s_journal, target);
}
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 6a79fd0..3436d53 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -309,7 +309,7 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh,
"Waiting for Godot: block %llu\n",
journal->j_devname,
(unsigned long long) bh->b_blocknr);
- jbd2_log_start_commit(journal, tid);
+ jbd2_log_start_commit(journal, tid, true);
jbd2_log_wait_commit(journal, tid);
ret = 1;
} else if (!buffer_dirty(bh)) {
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index f3ad159..19973eb 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -329,7 +329,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
int tag_bytes = journal_tag_bytes(journal);
struct buffer_head *cbh = NULL; /* For transactional checksums */
__u32 crc32_sum = ~0;
- int write_op = WRITE_SYNC;
+ int write_op = WRITE;
/*
* First job: lock down the current transaction and wait for
@@ -368,7 +368,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
* we unplug the device. We don't do explicit unplugging in here,
* instead we rely on sync_buffer() doing the unplug for us.
*/
- if (commit_transaction->t_synchronous_commit)
+ if (tid_geq(journal->j_commit_waited, commit_transaction->t_tid))
write_op = WRITE_SYNC_PLUG;
trace_jbd2_commit_locking(journal, commit_transaction);
stats.run.rs_wait = commit_transaction->t_max_wait;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 9e46869..e278fa2 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -475,7 +475,7 @@ int __jbd2_log_space_left(journal_t *journal)
/*
* Called under j_state_lock. Returns true if a transaction commit was started.
*/
-int __jbd2_log_start_commit(journal_t *journal, tid_t target)
+int __jbd2_log_start_commit(journal_t *journal, tid_t target, bool will_wait)
{
/*
* Are we already doing a recent enough commit?
@@ -485,7 +485,8 @@ int __jbd2_log_start_commit(journal_t *journal, tid_t target)
* We want a new commit: OK, mark the request and wakeup the
* commit thread. We do _not_ do the commit ourselves.
*/
-
+ if (will_wait && !tid_geq(journal->j_commit_waited, target))
+ journal->j_commit_waited = target;
journal->j_commit_request = target;
jbd_debug(1, "JBD: requesting commit %d/%d\n",
journal->j_commit_request,
@@ -496,12 +497,12 @@ int __jbd2_log_start_commit(journal_t *journal, tid_t target)
return 0;
}
-int jbd2_log_start_commit(journal_t *journal, tid_t tid)
+int jbd2_log_start_commit(journal_t *journal, tid_t tid, bool will_wait)
{
int ret;
write_lock(&journal->j_state_lock);
- ret = __jbd2_log_start_commit(journal, tid);
+ ret = __jbd2_log_start_commit(journal, tid, will_wait);
write_unlock(&journal->j_state_lock);
return ret;
}
@@ -524,7 +525,7 @@ int jbd2_journal_force_commit_nested(journal_t *journal)
read_lock(&journal->j_state_lock);
if (journal->j_running_transaction && !current->journal_info) {
transaction = journal->j_running_transaction;
- __jbd2_log_start_commit(journal, transaction->t_tid);
+ __jbd2_log_start_commit(journal, transaction->t_tid, true);
} else if (journal->j_committing_transaction)
transaction = journal->j_committing_transaction;
@@ -544,7 +545,7 @@ int jbd2_journal_force_commit_nested(journal_t *journal)
* if a transaction is going to be committed (or is currently already
* committing), and fills its tid in at *ptid
*/
-int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
+int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid, bool will_wait)
{
int ret = 0;
@@ -552,7 +553,7 @@ int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
if (journal->j_running_transaction) {
tid_t tid = journal->j_running_transaction->t_tid;
- __jbd2_log_start_commit(journal, tid);
+ __jbd2_log_start_commit(journal, tid, will_wait);
/* There's a running transaction and we've just made sure
* it's commit has been scheduled. */
if (ptid)
@@ -1559,7 +1560,7 @@ int jbd2_journal_flush(journal_t *journal)
/* Force everything buffered to the log... */
if (journal->j_running_transaction) {
transaction = journal->j_running_transaction;
- __jbd2_log_start_commit(journal, transaction->t_tid);
+ __jbd2_log_start_commit(journal, transaction->t_tid, true);
} else if (journal->j_committing_transaction)
transaction = journal->j_committing_transaction;
@@ -1675,7 +1676,7 @@ void __jbd2_journal_abort_hard(journal_t *journal)
journal->j_flags |= JBD2_ABORT;
transaction = journal->j_running_transaction;
if (transaction)
- __jbd2_log_start_commit(journal, transaction->t_tid);
+ __jbd2_log_start_commit(journal, transaction->t_tid, false);
write_unlock(&journal->j_state_lock);
}
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index faad2bd..c48e6e8 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -222,7 +222,7 @@ repeat:
atomic_sub(nblocks, &transaction->t_outstanding_credits);
prepare_to_wait(&journal->j_wait_transaction_locked, &wait,
TASK_UNINTERRUPTIBLE);
- __jbd2_log_start_commit(journal, transaction->t_tid);
+ __jbd2_log_start_commit(journal, transaction->t_tid, false);
read_unlock(&journal->j_state_lock);
schedule();
finish_wait(&journal->j_wait_transaction_locked, &wait);
@@ -465,7 +465,7 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, int gfp_mask)
spin_unlock(&transaction->t_handle_lock);
jbd_debug(2, "restarting handle %p\n", handle);
- __jbd2_log_start_commit(journal, transaction->t_tid);
+ __jbd2_log_start_commit(journal, transaction->t_tid, false);
read_unlock(&journal->j_state_lock);
lock_map_release(&handle->h_lockdep_map);
@@ -1361,8 +1361,6 @@ int jbd2_journal_stop(handle_t *handle)
}
}
- if (handle->h_sync)
- transaction->t_synchronous_commit = 1;
current->journal_info = NULL;
atomic_sub(handle->h_buffer_credits,
&transaction->t_outstanding_credits);
@@ -1383,15 +1381,16 @@ int jbd2_journal_stop(handle_t *handle)
jbd_debug(2, "transaction too old, requesting commit for "
"handle %p\n", handle);
- /* This is non-blocking */
- jbd2_log_start_commit(journal, transaction->t_tid);
-
/*
* Special case: JBD2_SYNC synchronous updates require us
* to wait for the commit to complete.
*/
if (handle->h_sync && !(current->flags & PF_MEMALLOC))
wait_for_commit = 1;
+
+ /* This is non-blocking */
+ jbd2_log_start_commit(journal, transaction->t_tid,
+ wait_for_commit);
}
/*
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 1fbb0e2..d493f32 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1659,7 +1659,7 @@ static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb,
goto out;
}
- if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) {
+ if (jbd2_journal_start_commit(osb->journal->j_journal, &target, true)) {
jbd2_log_wait_commit(osb->journal->j_journal, target);
ret = 1;
}
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 38f986d..45d9f82 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -414,7 +414,7 @@ static int ocfs2_sync_fs(struct super_block *sb, int wait)
}
if (jbd2_journal_start_commit(OCFS2_SB(sb)->journal->j_journal,
- &target)) {
+ &target, wait)) {
if (wait)
jbd2_log_wait_commit(OCFS2_SB(sb)->journal->j_journal,
target);
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 27e79c2..46aaf45 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -631,11 +631,6 @@ struct transaction_s
*/
atomic_t t_handle_count;
- /*
- * This transaction is being forced and some process is
- * waiting for it to finish.
- */
- unsigned int t_synchronous_commit:1;
unsigned int t_flushed_data_blocks:1;
/*
@@ -900,6 +895,13 @@ struct journal_s
tid_t j_commit_request;
/*
+ * Sequence number of the most recent transaction someone is waiting
+ * for to commit.
+ * [j_state_lock]
+ */
+ tid_t j_commit_waited;
+
+ /*
* Journal uuid: identifies the object (filesystem, LVM volume etc)
* backed by this journal. This will eventually be replaced by an array
* of uuids, allowing us to index multiple devices within a single
@@ -1200,9 +1202,9 @@ extern void jbd2_journal_switch_revoke_table(journal_t *journal);
*/
int __jbd2_log_space_left(journal_t *); /* Called with journal locked */
-int jbd2_log_start_commit(journal_t *journal, tid_t tid);
-int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
-int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
+int jbd2_log_start_commit(journal_t *journal, tid_t tid, bool will_wait);
+int __jbd2_log_start_commit(journal_t *journal, tid_t tid, bool will_wait);
+int jbd2_journal_start_commit(journal_t *journal, tid_t *tid, bool will_wait);
int jbd2_journal_force_commit_nested(journal_t *journal);
int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
int jbd2_log_do_checkpoint(journal_t *journal);
--
1.7.1