Btrfs: kill the orphan space calculation for snapshots

This patch kills off the calculation for the amount of space needed for the
orphan operations during a snapshot.  The thing is we only do snapshots on
commit, so any space that is in the block_rsv->freed[] isn't going to be in the
new snapshot anyway, so there isn't any reason to require that space to be
reserved for the snapshot to occur.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
This commit is contained in:
Josef Bacik 2011-08-04 15:34:57 -04:00
parent 7709cde33f
commit dba68306f3
3 changed files with 0 additions and 90 deletions

View File

@ -2577,11 +2577,6 @@ int btrfs_update_inode(struct btrfs_trans_handle *trans,
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode);
int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
int btrfs_orphan_cleanup(struct btrfs_root *root);
void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,
struct btrfs_pending_snapshot *pending,
u64 *bytes_to_reserve);
void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,
struct btrfs_pending_snapshot *pending);
void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size);

View File

@ -2079,89 +2079,6 @@ void btrfs_run_delayed_iputs(struct btrfs_root *root)
up_read(&root->fs_info->cleanup_work_sem);
}
/*
* calculate extra metadata reservation when snapshotting a subvolume
* contains orphan files.
*/
void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,
struct btrfs_pending_snapshot *pending,
u64 *bytes_to_reserve)
{
struct btrfs_root *root;
struct btrfs_block_rsv *block_rsv;
u64 num_bytes;
int index;
root = pending->root;
if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
return;
block_rsv = root->orphan_block_rsv;
/* orphan block reservation for the snapshot */
num_bytes = block_rsv->size;
/*
* after the snapshot is created, COWing tree blocks may use more
* space than it frees. So we should make sure there is enough
* reserved space.
*/
index = trans->transid & 0x1;
if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
num_bytes += block_rsv->size -
(block_rsv->reserved + block_rsv->freed[index]);
}
*bytes_to_reserve += num_bytes;
}
void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,
struct btrfs_pending_snapshot *pending)
{
struct btrfs_root *root = pending->root;
struct btrfs_root *snap = pending->snap;
struct btrfs_block_rsv *block_rsv;
u64 num_bytes;
int index;
int ret;
if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
return;
/* refill source subvolume's orphan block reservation */
block_rsv = root->orphan_block_rsv;
index = trans->transid & 0x1;
if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
num_bytes = block_rsv->size -
(block_rsv->reserved + block_rsv->freed[index]);
ret = btrfs_block_rsv_migrate(&pending->block_rsv,
root->orphan_block_rsv,
num_bytes);
BUG_ON(ret);
}
/* setup orphan block reservation for the snapshot */
block_rsv = btrfs_alloc_block_rsv(snap);
BUG_ON(!block_rsv);
btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
snap->orphan_block_rsv = block_rsv;
num_bytes = root->orphan_block_rsv->size;
ret = btrfs_block_rsv_migrate(&pending->block_rsv,
block_rsv, num_bytes);
BUG_ON(ret);
#if 0
/* insert orphan item for the snapshot */
WARN_ON(!root->orphan_item_inserted);
ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
snap->root_key.objectid);
BUG_ON(ret);
snap->orphan_item_inserted = 1;
#endif
}
enum btrfs_orphan_cleanup_state {
ORPHAN_CLEANUP_STARTED = 1,
ORPHAN_CLEANUP_DONE = 2,

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@ -911,7 +911,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
}
btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
btrfs_orphan_pre_snapshot(trans, pending, &to_reserve);
if (to_reserve > 0) {
ret = btrfs_block_rsv_add(trans, root, &pending->block_rsv,
@ -1002,7 +1001,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
BUG_ON(IS_ERR(pending->snap));
btrfs_reloc_post_snapshot(trans, pending);
btrfs_orphan_post_snapshot(trans, pending);
fail:
kfree(new_root_item);
trans->block_rsv = rsv;