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Btrfs: Change push_leaf_{leaf,right} to empty the src leave during it…
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…em deletion

Signed-off-by: Chris Mason <chris.mason@oracle.com>
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Chris Mason committed Sep 25, 2008
1 parent e644d02 commit 34a3821
Showing 1 changed file with 50 additions and 24 deletions.
74 changes: 50 additions & 24 deletions fs/btrfs/ctree.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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)
Expand All @@ -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);
Expand All @@ -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);

Expand Down Expand Up @@ -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) {
Expand All @@ -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);
Expand All @@ -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];
Expand All @@ -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;
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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 */
Expand Down Expand Up @@ -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++) {
Expand All @@ -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);
Expand Down Expand Up @@ -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;
}
Expand Down Expand Up @@ -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;
}
Expand Down

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