Btrfs: dynamic allocation of path struct
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 37b87e2..d785b72 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -15,7 +15,7 @@
static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
*root, u64 blocknr, u64 num_blocks)
{
- struct btrfs_path path;
+ struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct btrfs_leaf *l;
@@ -25,23 +25,26 @@
find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1,
&ins);
- btrfs_init_path(&path);
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
key.objectid = blocknr;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
key.offset = num_blocks;
- ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
+ ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
0, 1);
if (ret != 0)
BUG();
BUG_ON(ret != 0);
- l = btrfs_buffer_leaf(path.nodes[0]);
- item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
+ l = btrfs_buffer_leaf(path->nodes[0]);
+ item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(item);
btrfs_set_extent_refs(item, refs + 1);
- btrfs_mark_buffer_dirty(path.nodes[0]);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
- btrfs_release_path(root->fs_info->extent_root, &path);
+ btrfs_release_path(root->fs_info->extent_root, path);
+ btrfs_free_path(path);
finish_current_insert(trans, root->fs_info->extent_root);
del_pending_extents(trans, root->fs_info->extent_root);
return 0;
@@ -50,24 +53,27 @@
static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
*root, u64 blocknr, u64 num_blocks, u32 *refs)
{
- struct btrfs_path path;
+ struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct btrfs_leaf *l;
struct btrfs_extent_item *item;
- btrfs_init_path(&path);
+
+ path = btrfs_alloc_path();
+ btrfs_init_path(path);
key.objectid = blocknr;
key.offset = num_blocks;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
- ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
+ ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
0, 0);
if (ret != 0)
BUG();
- l = btrfs_buffer_leaf(path.nodes[0]);
- item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
+ l = btrfs_buffer_leaf(path->nodes[0]);
+ item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
*refs = btrfs_extent_refs(item);
- btrfs_release_path(root->fs_info->extent_root, &path);
+ btrfs_release_path(root->fs_info->extent_root, path);
+ btrfs_free_path(path);
return 0;
}
@@ -200,7 +206,7 @@
static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
*root, u64 blocknr, u64 num_blocks, int pin)
{
- struct btrfs_path path;
+ struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
@@ -215,20 +221,22 @@
key.offset = num_blocks;
find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
- btrfs_init_path(&path);
- ret = btrfs_search_slot(trans, extent_root, &key, &path, -1, 1);
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
if (ret) {
printk("failed to find %Lu\n", key.objectid);
btrfs_print_tree(extent_root, extent_root->node);
printk("failed to find %Lu\n", key.objectid);
BUG();
}
- ei = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
+ ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_extent_item);
BUG_ON(ei->refs == 0);
refs = btrfs_extent_refs(ei) - 1;
btrfs_set_extent_refs(ei, refs);
- btrfs_mark_buffer_dirty(path.nodes[0]);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
if (refs == 0) {
u64 super_blocks_used;
@@ -240,13 +248,14 @@
super_blocks_used = btrfs_super_blocks_used(info->disk_super);
btrfs_set_super_blocks_used(info->disk_super,
super_blocks_used - num_blocks);
- ret = btrfs_del_item(trans, extent_root, &path);
+ ret = btrfs_del_item(trans, extent_root, path);
if (extent_root->fs_info->last_insert.objectid > blocknr)
extent_root->fs_info->last_insert.objectid = blocknr;
if (ret)
BUG();
}
- btrfs_release_path(extent_root, &path);
+ btrfs_release_path(extent_root, path);
+ btrfs_free_path(path);
finish_current_insert(trans, extent_root);
return ret;
}
@@ -319,7 +328,7 @@
*orig_root, u64 num_blocks, u64 search_start, u64
search_end, struct btrfs_key *ins)
{
- struct btrfs_path path;
+ struct btrfs_path *path;
struct btrfs_key key;
int ret;
u64 hole_size = 0;
@@ -339,24 +348,25 @@
ins->flags = 0;
btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
+ path = btrfs_alloc_path();
check_failed:
- btrfs_init_path(&path);
+ btrfs_init_path(path);
ins->objectid = search_start;
ins->offset = 0;
start_found = 0;
- ret = btrfs_search_slot(trans, root, ins, &path, 0, 0);
+ ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
if (ret < 0)
goto error;
- if (path.slots[0] > 0)
- path.slots[0]--;
+ if (path->slots[0] > 0)
+ path->slots[0]--;
while (1) {
- l = btrfs_buffer_leaf(path.nodes[0]);
- slot = path.slots[0];
+ l = btrfs_buffer_leaf(path->nodes[0]);
+ slot = path->slots[0];
if (slot >= btrfs_header_nritems(&l->header)) {
- ret = btrfs_next_leaf(root, &path);
+ ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
@@ -387,14 +397,14 @@
}
start_found = 1;
last_block = key.objectid + key.offset;
- path.slots[0]++;
+ path->slots[0]++;
}
// FIXME -ENOSPC
check_pending:
/* we have to make sure we didn't find an extent that has already
* been allocated by the map tree or the original allocation
*/
- btrfs_release_path(root, &path);
+ btrfs_release_path(root, path);
BUG_ON(ins->objectid < search_start);
for (test_block = ins->objectid;
test_block < ins->objectid + total_needed; test_block++) {
@@ -410,9 +420,11 @@
root->fs_info->current_insert.flags = 0;
root->fs_info->last_insert.objectid = ins->objectid;
ins->offset = num_blocks;
+ btrfs_free_path(path);
return 0;
error:
- btrfs_release_path(root, &path);
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
return ret;
}
@@ -533,6 +545,8 @@
int ret;
u32 refs;
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
ret = lookup_block_ref(trans, root, path->nodes[*level]->b_blocknr,
1, &refs);
BUG_ON(ret);
@@ -542,6 +556,8 @@
* walk down to the last node level and free all the leaves
*/
while(*level >= 0) {
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
cur = path->nodes[*level];
if (btrfs_header_level(btrfs_buffer_header(cur)) != *level)
WARN_ON(1);
@@ -564,6 +580,7 @@
continue;
}
next = read_tree_block(root, blocknr);
+ WARN_ON(*level <= 0);
if (path->nodes[*level-1])
btrfs_block_release(root, path->nodes[*level-1]);
path->nodes[*level-1] = next;
@@ -571,6 +588,8 @@
path->slots[*level] = 0;
}
out:
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
ret = btrfs_free_extent(trans, root,
path->nodes[*level]->b_blocknr, 1, 1);
btrfs_block_release(root, path->nodes[*level]);
@@ -622,33 +641,36 @@
int ret = 0;
int wret;
int level;
- struct btrfs_path path;
+ struct btrfs_path *path;
int i;
int orig_level;
- btrfs_init_path(&path);
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
level = btrfs_header_level(btrfs_buffer_header(snap));
orig_level = level;
- path.nodes[level] = snap;
- path.slots[level] = 0;
+ path->nodes[level] = snap;
+ path->slots[level] = 0;
while(1) {
- wret = walk_down_tree(trans, root, &path, &level);
+ wret = walk_down_tree(trans, root, path, &level);
if (wret > 0)
break;
if (wret < 0)
ret = wret;
- wret = walk_up_tree(trans, root, &path, &level);
+ wret = walk_up_tree(trans, root, path, &level);
if (wret > 0)
break;
if (wret < 0)
ret = wret;
}
for (i = 0; i <= orig_level; i++) {
- if (path.nodes[i]) {
- btrfs_block_release(root, path.nodes[i]);
+ if (path->nodes[i]) {
+ btrfs_block_release(root, path->nodes[i]);
}
}
+ btrfs_free_path(path);
return ret;
}
