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authorChris Mason <chris.mason@oracle.com>2007-11-07 21:31:03 +0300
committerChris Mason <chris.mason@oracle.com>2008-09-25 19:03:57 +0400
commit34a3821873aeabff2607c8093bce82cd1fbcfd60 (patch)
treebf204e4a0b45fd764b7fadea23e45034021675c4 /fs/btrfs/ctree.c
parente644d021e328d3902559e5db687383f2da85993c (diff)
downloadlinux-34a3821873aeabff2607c8093bce82cd1fbcfd60.tar.xz
Btrfs: Change push_leaf_{leaf,right} to empty the src leave during item deletion
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/ctree.c')
-rw-r--r--fs/btrfs/ctree.c74
1 files changed, 50 insertions, 24 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index ea9b46699349..1b47fe71e0b4 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1394,19 +1394,21 @@ int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
* room, 0 if everything worked out and < 0 if there were major errors.
*/
static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_path *path, int data_size)
+ *root, struct btrfs_path *path, int data_size,
+ int empty)
{
struct extent_buffer *left = path->nodes[0];
struct extent_buffer *right;
struct extent_buffer *upper;
struct btrfs_disk_key disk_key;
int slot;
- int i;
+ u32 i;
int free_space;
int push_space = 0;
int push_items = 0;
struct btrfs_item *item;
u32 left_nritems;
+ u32 nr;
u32 right_nritems;
u32 data_end;
u32 this_item_size;
@@ -1447,7 +1449,13 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
return 1;
}
- for (i = left_nritems - 1; i >= 1; i--) {
+ if (empty)
+ nr = 0;
+ else
+ nr = 1;
+
+ i = left_nritems - 1;
+ while (i >= nr) {
item = btrfs_item_nr(left, i);
if (path->slots[0] == i)
@@ -1466,6 +1474,9 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
break;
push_items++;
push_space += this_item_size + sizeof(*item);
+ if (i == 0)
+ break;
+ i--;
}
if (left->map_token) {
unmap_extent_buffer(left, left->map_token, KM_USER1);
@@ -1477,11 +1488,12 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
return 1;
}
- if (push_items == left_nritems)
+ if (!empty && push_items == left_nritems)
WARN_ON(1);
/* push left to right */
right_nritems = btrfs_header_nritems(right);
+
push_space = btrfs_item_end_nr(left, left_nritems - push_items);
push_space -= leaf_data_end(root, left);
@@ -1511,7 +1523,6 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
right_nritems += push_items;
btrfs_set_header_nritems(right, right_nritems);
push_space = BTRFS_LEAF_DATA_SIZE(root);
-
for (i = 0; i < right_nritems; i++) {
item = btrfs_item_nr(right, i);
if (!right->map_token) {
@@ -1532,7 +1543,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
left_nritems -= push_items;
btrfs_set_header_nritems(left, left_nritems);
- btrfs_mark_buffer_dirty(left);
+ if (left_nritems)
+ btrfs_mark_buffer_dirty(left);
btrfs_mark_buffer_dirty(right);
btrfs_item_key(right, &disk_key, 0);
@@ -1555,7 +1567,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
* least data_size bytes. returns zero if the push worked, nonzero otherwise
*/
static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_path *path, int data_size)
+ *root, struct btrfs_path *path, int data_size,
+ int empty)
{
struct btrfs_disk_key disk_key;
struct extent_buffer *right = path->nodes[0];
@@ -1568,6 +1581,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
struct btrfs_item *item;
u32 old_left_nritems;
u32 right_nritems;
+ u32 nr;
int ret = 0;
int wret;
u32 this_item_size;
@@ -1607,7 +1621,12 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
return 1;
}
- for (i = 0; i < right_nritems - 1; i++) {
+ if (empty)
+ nr = right_nritems;
+ else
+ nr = right_nritems - 1;
+
+ for (i = 0; i < nr; i++) {
item = btrfs_item_nr(right, i);
if (!right->map_token) {
map_extent_buffer(right, (unsigned long)item,
@@ -1637,7 +1656,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
free_extent_buffer(left);
return 1;
}
- if (push_items == btrfs_header_nritems(right))
+ if (!empty && push_items == btrfs_header_nritems(right))
WARN_ON(1);
/* push data from right to left */
@@ -1681,20 +1700,26 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
}
/* fixup right node */
- push_space = btrfs_item_offset_nr(right, push_items - 1) -
- leaf_data_end(root, right);
- memmove_extent_buffer(right, btrfs_leaf_data(right) +
- BTRFS_LEAF_DATA_SIZE(root) - push_space,
- btrfs_leaf_data(right) +
- leaf_data_end(root, right), push_space);
-
- memmove_extent_buffer(right, btrfs_item_nr_offset(0),
+ if (push_items > right_nritems) {
+ printk("push items %d nr %u\n", push_items, right_nritems);
+ WARN_ON(1);
+ }
+
+ if (push_items < right_nritems) {
+ push_space = btrfs_item_offset_nr(right, push_items - 1) -
+ leaf_data_end(root, right);
+ memmove_extent_buffer(right, btrfs_leaf_data(right) +
+ BTRFS_LEAF_DATA_SIZE(root) - push_space,
+ btrfs_leaf_data(right) +
+ leaf_data_end(root, right), push_space);
+
+ memmove_extent_buffer(right, btrfs_item_nr_offset(0),
btrfs_item_nr_offset(push_items),
(btrfs_header_nritems(right) - push_items) *
sizeof(struct btrfs_item));
- right_nritems = btrfs_header_nritems(right) - push_items;
- btrfs_set_header_nritems(right, right_nritems);
+ }
+ btrfs_set_header_nritems(right, right_nritems - push_items);
push_space = BTRFS_LEAF_DATA_SIZE(root);
for (i = 0; i < right_nritems; i++) {
@@ -1717,7 +1742,8 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
}
btrfs_mark_buffer_dirty(left);
- btrfs_mark_buffer_dirty(right);
+ if (right_nritems)
+ btrfs_mark_buffer_dirty(right);
btrfs_item_key(right, &disk_key, 0);
wret = fixup_low_keys(trans, root, path, &disk_key, 1);
@@ -1768,12 +1794,12 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
/* first try to make some room by pushing left and right */
if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
- wret = push_leaf_right(trans, root, path, data_size);
+ wret = push_leaf_right(trans, root, path, data_size, 0);
if (wret < 0) {
return wret;
}
if (wret) {
- wret = push_leaf_left(trans, root, path, data_size);
+ wret = push_leaf_left(trans, root, path, data_size, 0);
if (wret < 0)
return wret;
}
@@ -2403,13 +2429,13 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
slot = path->slots[1];
extent_buffer_get(leaf);
- wret = push_leaf_right(trans, root, path, 1);
+ wret = push_leaf_right(trans, root, path, 1, 1);
if (wret < 0 && wret != -ENOSPC)
ret = wret;
if (path->nodes[0] == leaf &&
btrfs_header_nritems(leaf)) {
- wret = push_leaf_left(trans, root, path, 1);
+ wret = push_leaf_left(trans, root, path, 1, 1);
if (wret < 0 && wret != -ENOSPC)
ret = wret;
}