iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Btrfs: fix off-by-one logic error in btrfs_realloc_node

Browse Source 
The end_slot variable actually matches the number of pointers in the
node and not the last slot (which is 'nritems - 1'). Therefore in order
to check that the current slot in the for loop doesn't match the last
one, the correct logic is to check if 'i' is less than 'end_slot - 1'
and not 'end_slot - 2'.

Fix this and set end_slot to be 'nritems - 1', as it's less confusing
since the variable name implies it's inclusive rather then exclusive.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Filipe Manana 2015-02-23 19:48:52 +00:00 committed by Chris Mason
parent e8c1c76e80
commit 5dfe2be7ea
1 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
fs/btrfs/ctree.c
View File

@ -1645,14 +1645,14 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
parent_nritems = btrfs_header_nritems(parent);
blocksize = root->nodesize;
end_slot = parent_nritems;
end_slot = parent_nritems - 1;
if (parent_nritems == 1)
if (parent_nritems <= 1)
return 0;
btrfs_set_lock_blocking(parent);
for (i = start_slot; i < end_slot; i++) {
for (i = start_slot; i <= end_slot; i++) {
int close = 1;
btrfs_node_key(parent, &disk_key, i);
@ -1669,7 +1669,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
other = btrfs_node_blockptr(parent, i - 1);
close = close_blocks(blocknr, other, blocksize);
}
if (!close && i < end_slot - 2) {
if (!close && i < end_slot) {
other = btrfs_node_blockptr(parent, i + 1);
close = close_blocks(blocknr, other, blocksize);
}