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From: Miao Xie <miaox@cn.fujitsu.com>
To: Linux Btrfs <linux-btrfs@vger.kernel.org>
Subject: [PATCH 2/9] Btrfs: don't start a new transaction when starting sync
Date: Mon, 26 Nov 2012 16:41:29 +0800	[thread overview]
Message-ID: <50B32B39.2020908@cn.fujitsu.com> (raw)
In-Reply-To: <50B32ABF.7040803@cn.fujitsu.com>

If there is no running transaction in the fs, we needn't start a new one when
we want to start sync.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
 fs/btrfs/ioctl.c       | 14 ++++++++++----
 fs/btrfs/transaction.c | 13 ++++++++-----
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fd3fff5..5102747 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3045,16 +3045,22 @@ static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
 	u64 transid;
 	int ret;
 
-	trans = btrfs_start_transaction(root, 0);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
+	trans = btrfs_attach_transaction(root);
+	if (IS_ERR(trans)) {
+		if (PTR_ERR(trans) != -ENOENT)
+			return PTR_ERR(trans);
+
+		/* No running transaction, don't bother */
+		transid = root->fs_info->last_trans_committed;
+		goto out;
+	}
 	transid = trans->transid;
 	ret = btrfs_commit_transaction_async(trans, root, 0);
 	if (ret) {
 		btrfs_end_transaction(trans, root);
 		return ret;
 	}
-
+out:
 	if (argp)
 		if (copy_to_user(argp, &transid, sizeof(transid)))
 			return -EFAULT;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 04bbfb1..350e9c4 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1309,9 +1309,10 @@ static void do_async_commit(struct work_struct *work)
 	 * We've got freeze protection passed with the transaction.
 	 * Tell lockdep about it.
 	 */
-	rwsem_acquire_read(
-		&ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
-		0, 1, _THIS_IP_);
+	if (ac->newtrans->type < TRANS_JOIN_NOLOCK)
+		rwsem_acquire_read(
+		     &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
+		     0, 1, _THIS_IP_);
 
 	current->journal_info = ac->newtrans;
 
@@ -1349,8 +1350,10 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 	 * Tell lockdep we've released the freeze rwsem, since the
 	 * async commit thread will be the one to unlock it.
 	 */
-	rwsem_release(&root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
-		      1, _THIS_IP_);
+	if (trans->type < TRANS_JOIN_NOLOCK)
+		rwsem_release(
+			&root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
+			1, _THIS_IP_);
 
 	schedule_delayed_work(&ac->work, 0);
 
-- 
1.7.11.7


  parent reply	other threads:[~2012-11-26  8:41 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-26  8:39 [PATCH 0/9] random fix for btrfs_ioctl() Miao Xie
2012-11-26  8:40 ` [PATCH 1/9] Btrfs: pass root object into btrfs_ioctl_{start, wait}_sync() Miao Xie
2012-11-26  8:41 ` Miao Xie [this message]
2012-11-26  8:42 ` [PATCH 3/9] Btrfs: fix wrong return value of btrfs_wait_for_commit() Miao Xie
2012-11-26  8:43 ` [PATCH 4/9] Btrfs: get write access when setting the default subvolume Miao Xie
2012-11-26  8:43 ` [PATCH 5/9] Btrfs: get write access when doing resize fs Miao Xie
2012-11-26  8:44 ` [PATCH 6/9] Btrfs: get write access when removing a device Miao Xie
2012-11-26  8:48 ` [PATCH 7/9] Btrfs: get write access for scrub Miao Xie
2012-11-26  8:50 ` [PATCH 8/9] Btrfs: get write access for qgroup operations Miao Xie
2012-11-26  8:51 ` [RFC PATCH 9/9] Btrfs: get write access for adding device Miao Xie
2012-12-12  2:52   ` Miao Xie

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