Miao Xie
2014-Mar-06 05:54 UTC
[PATCH V2 01/10] Btrfs: fix early enospc due to the race of the two ordered extent wait
btrfs_wait_ordered_roots() moves all the list entries to a new list,
and then deals with them one by one. But if the other task invokes this
function at that time, it would get a empty list. It makes the enospc
error happens more early. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
Changelog v1 -> v2:
- New patch.
---
fs/btrfs/ordered-data.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 138a7d7..a6ba75e 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -589,7 +589,7 @@ static void btrfs_run_ordered_extent_work(struct btrfs_work
*work)
* wait for all the ordered extents in a root. This is done when balancing
* space between drives.
*/
-int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
+static int __btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
{
struct list_head splice, works;
struct btrfs_ordered_extent *ordered, *next;
@@ -598,7 +598,6 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int
nr)
INIT_LIST_HEAD(&splice);
INIT_LIST_HEAD(&works);
- mutex_lock(&root->fs_info->ordered_operations_mutex);
spin_lock(&root->ordered_extent_lock);
list_splice_init(&root->ordered_extents, &splice);
while (!list_empty(&splice) && nr) {
@@ -629,6 +628,16 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int
nr)
btrfs_put_ordered_extent(ordered);
cond_resched();
}
+
+ return count;
+}
+
+int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
+{
+ int count;
+
+ mutex_lock(&root->fs_info->ordered_operations_mutex);
+ count = __btrfs_wait_ordered_extents(root, nr);
mutex_unlock(&root->fs_info->ordered_operations_mutex);
return count;
@@ -642,6 +651,7 @@ void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info,
int nr)
INIT_LIST_HEAD(&splice);
+ mutex_lock(&fs_info->ordered_operations_mutex);
spin_lock(&fs_info->ordered_root_lock);
list_splice_init(&fs_info->ordered_roots, &splice);
while (!list_empty(&splice) && nr) {
@@ -653,7 +663,7 @@ void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info,
int nr)
&fs_info->ordered_roots);
spin_unlock(&fs_info->ordered_root_lock);
- done = btrfs_wait_ordered_extents(root, nr);
+ done = __btrfs_wait_ordered_extents(root, nr);
btrfs_put_fs_root(root);
spin_lock(&fs_info->ordered_root_lock);
@@ -664,6 +674,7 @@ void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info,
int nr)
}
list_splice_tail(&splice, &fs_info->ordered_roots);
spin_unlock(&fs_info->ordered_root_lock);
+ mutex_unlock(&fs_info->ordered_operations_mutex);
}
/*
--
1.8.1.4
--
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