btrfs: fall back to global reservation when removing subvolumes
I recently did some ENOSPC testing that involved filling the disk
while create and removing snapshots in a loop. During the test cycle,
I ran into an ENOSPC when trying to remove a snapshot, leaving the fs
stuck in ENOSPC even after a umount/mount cycle.
This patch allow subvolume removal to fall back onto the global
block reservation in order to succeed when it would have failed
otherwise.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e795bf1..8cc0332 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3175,7 +3175,7 @@
int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
struct btrfs_block_rsv *rsv,
int nitems,
- u64 *qgroup_reserved);
+ u64 *qgroup_reserved, bool use_global_rsv);
void btrfs_subvolume_release_metadata(struct btrfs_root *root,
struct btrfs_block_rsv *rsv,
u64 qgroup_reserved);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3e7e05e..7bea4d2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4742,10 +4742,12 @@
int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
struct btrfs_block_rsv *rsv,
int items,
- u64 *qgroup_reserved)
+ u64 *qgroup_reserved,
+ bool use_global_rsv)
{
u64 num_bytes;
int ret;
+ struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
if (root->fs_info->quota_enabled) {
/* One for parent inode, two for dir entries */
@@ -4764,6 +4766,10 @@
BTRFS_BLOCK_GROUP_METADATA);
ret = btrfs_block_rsv_add(root, rsv, num_bytes,
BTRFS_RESERVE_FLUSH_ALL);
+
+ if (ret == -ENOSPC && use_global_rsv)
+ ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes);
+
if (ret) {
if (*qgroup_reserved)
btrfs_qgroup_free(root, *qgroup_reserved);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 238a055..841044b 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -396,7 +396,7 @@
* of create_snapshot().
*/
ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
- 7, &qgroup_reserved);
+ 7, &qgroup_reserved, false);
if (ret)
return ret;
@@ -576,7 +576,8 @@
*/
ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
&pending_snapshot->block_rsv, 7,
- &pending_snapshot->qgroup_reserved);
+ &pending_snapshot->qgroup_reserved,
+ false);
if (ret)
goto out;
@@ -2174,7 +2175,7 @@
* ref/backref.
*/
err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
- 5, &qgroup_reserved);
+ 5, &qgroup_reserved, true);
if (err)
goto out_up_write;