Btrfs: don't traverse the ordered operation list repeatedly

btrfs_run_ordered_operations() needn't traverse the ordered operation list
repeatedly, it is because the transaction commiter will invoke it again when
there is no other writer in this transaction, it can ensure that no one can
add new objects into the ordered operation list.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Miao Xie 2013-01-22 10:52:04 +00:00 committed by Josef Bacik
parent 63607cc86a
commit 5b947f1ba9

View file

@ -626,14 +626,10 @@ int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
mutex_lock(&root->fs_info->ordered_operations_mutex);
spin_lock(&root->fs_info->ordered_extent_lock);
again:
list_splice_init(&root->fs_info->ordered_operations, &splice);
while (!list_empty(&splice)) {
btrfs_inode = list_entry(splice.next, struct btrfs_inode,
ordered_operations);
inode = &btrfs_inode->vfs_inode;
list_del_init(&btrfs_inode->ordered_operations);
@ -642,22 +638,20 @@ again:
* the inode may be getting freed (in sys_unlink path).
*/
inode = igrab(inode);
if (!wait && inode) {
list_add_tail(&BTRFS_I(inode)->ordered_operations,
&root->fs_info->ordered_operations);
}
if (!inode)
continue;
if (!wait)
list_add_tail(&BTRFS_I(inode)->ordered_operations,
&root->fs_info->ordered_operations);
spin_unlock(&root->fs_info->ordered_extent_lock);
work = btrfs_alloc_delalloc_work(inode, wait, 1);
if (!work) {
spin_lock(&root->fs_info->ordered_extent_lock);
if (list_empty(&BTRFS_I(inode)->ordered_operations))
list_add_tail(&btrfs_inode->ordered_operations,
&splice);
spin_lock(&root->fs_info->ordered_extent_lock);
list_splice_tail(&splice,
&root->fs_info->ordered_operations);
spin_unlock(&root->fs_info->ordered_extent_lock);
@ -671,9 +665,6 @@ again:
cond_resched();
spin_lock(&root->fs_info->ordered_extent_lock);
}
if (wait && !list_empty(&root->fs_info->ordered_operations))
goto again;
spin_unlock(&root->fs_info->ordered_extent_lock);
out:
list_for_each_entry_safe(work, next, &works, list) {