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Code Issues Releases Wiki Activity

Btrfs: Remove extent back refs in batches, and avoid duplicate searches

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Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2008-02-18 16:33:44 -05:00
parent d7fc640e6f
commit 952fccac50
1 changed files with 54 additions and 9 deletions
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63
fs/btrfs/extent-tree.c
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@ -1251,6 +1251,9 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
struct btrfs_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
int ret;
int extent_slot = 0;
int found_extent = 0;
int num_to_del = 1;
struct btrfs_extent_item *ei;
u32 refs;
@ -1267,7 +1270,24 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
ref_generation,
owner_objectid, owner_offset, 1);
if (ret == 0) {
ret = btrfs_del_item(trans, extent_root, path);
struct btrfs_key found_key;
extent_slot = path->slots[0];
while(extent_slot > 0) {
extent_slot--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
extent_slot);
if (found_key.objectid != bytenr)
break;
if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
found_key.offset == num_bytes) {
found_extent = 1;
break;
}
if (path->slots[0] - extent_slot > 5)
break;
}
if (!found_extent)
ret = btrfs_del_item(trans, extent_root, path);
} else {
btrfs_print_leaf(extent_root, path->nodes[0]);
WARN_ON(1);
@ -1276,21 +1296,46 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
root_objectid, ref_generation, owner_objectid,
owner_offset);
}
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
if (ret < 0)
return ret;
BUG_ON(ret);
if (!found_extent) {
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
if (ret < 0)
return ret;
BUG_ON(ret);
extent_slot = path->slots[0];
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
ei = btrfs_item_ptr(leaf, extent_slot,
struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
BUG_ON(refs == 0);
refs -= 1;
btrfs_set_extent_refs(leaf, ei, refs);
btrfs_mark_buffer_dirty(leaf);
if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
/* if the back ref and the extent are next to each other
* they get deleted below in one shot
*/
path->slots[0] = extent_slot;
num_to_del = 2;
} else if (found_extent) {
/* otherwise delete the extent back ref */
ret = btrfs_del_item(trans, extent_root, path);
BUG_ON(ret);
/* if refs are 0, we need to setup the path for deletion */
if (refs == 0) {
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root, &key, path,
-1, 1);
if (ret < 0)
return ret;
BUG_ON(ret);
}
}
if (refs == 0) {
u64 super_used;
u64 root_used;
@ -1311,8 +1356,8 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
root_used = btrfs_root_used(&root->root_item);
btrfs_set_root_used(&root->root_item,
root_used - num_bytes);
ret = btrfs_del_item(trans, extent_root, path);
ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
num_to_del);
if (ret) {
return ret;
}