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Simplify btrfs_get_parent(), fix use-after-free bug

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Date: Mon, 18 Aug 2008 22:50:22 +0100
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
David Woodhouse 2008-08-18 22:50:22 +01:00 committed by Chris Mason
parent 32d48fa1af
commit 87acb4ef9b
1 changed files with 12 additions and 16 deletions
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24
fs/btrfs/export.c
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@ -147,7 +147,6 @@ static struct dentry *btrfs_get_parent(struct dentry *child)
struct btrfs_key key;
struct btrfs_path *path;
struct extent_buffer *leaf;
u32 nritems;
int slot;
u64 objectid;
int ret;
@ -156,27 +155,24 @@ static struct dentry *btrfs_get_parent(struct dentry *child)
key.objectid = dir->i_ino;
btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
BUG_ON(ret == 0);
ret = 0;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
leaf = path->nodes[0];
slot = path->slots[0];
nritems = btrfs_header_nritems(leaf);
if (slot >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret) {
if (ret < 0 || slot == 0) {
btrfs_free_path(path);
goto out;
}
leaf = path->nodes[0];
slot = path->slots[0];
}
btrfs_free_path(path);
/* btrfs_search_slot() returns the slot where we'd want to insert
an INODE_REF_KEY for parent inode #0xFFFFFFFFFFFFFFFF. The _real_
one, telling us what the parent inode _actually_ is, will be in
the slot _before_ the one that btrfs_search_slot() returns. */
slot--;
btrfs_item_key_to_cpu(leaf, &key, slot);
btrfs_free_path(path);
if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY)
goto out;