Btrfs: delay commits during fsync to allow more writers
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 00b118a..6933ab1 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -694,22 +694,36 @@
{
struct inode *inode = dentry->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
- int ret;
+ int ret = 0;
struct btrfs_trans_handle *trans;
/*
- * FIXME, use inode generation number to check if we can skip the
- * commit
+ * check the transaction that last modified this inode
+ * and see if its already been committed
*/
mutex_lock(&root->fs_info->fs_mutex);
+ if (!BTRFS_I(inode)->last_trans)
+ goto out;
+ mutex_lock(&root->fs_info->trans_mutex);
+ if (BTRFS_I(inode)->last_trans <=
+ root->fs_info->last_trans_committed) {
+ BTRFS_I(inode)->last_trans = 0;
+ mutex_unlock(&root->fs_info->trans_mutex);
+ goto out;
+ }
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ /*
+ * ok we haven't committed the transaction yet, lets do a commit
+ */
trans = btrfs_start_transaction(root, 1);
if (!trans) {
ret = -ENOMEM;
goto out;
}
ret = btrfs_commit_transaction(trans, root);
- mutex_unlock(&root->fs_info->fs_mutex);
out:
+ mutex_unlock(&root->fs_info->fs_mutex);
return ret > 0 ? EIO : ret;
}
