Commit 5dfe2be7 authored by Filipe Manana's avatar Filipe Manana Committed by Chris Mason

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

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: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent e8c1c76e
...@@ -1645,14 +1645,14 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, ...@@ -1645,14 +1645,14 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
parent_nritems = btrfs_header_nritems(parent); parent_nritems = btrfs_header_nritems(parent);
blocksize = root->nodesize; blocksize = root->nodesize;
end_slot = parent_nritems; end_slot = parent_nritems - 1;
if (parent_nritems == 1) if (parent_nritems <= 1)
return 0; return 0;
btrfs_set_lock_blocking(parent); btrfs_set_lock_blocking(parent);
for (i = start_slot; i < end_slot; i++) { for (i = start_slot; i <= end_slot; i++) {
int close = 1; int close = 1;
btrfs_node_key(parent, &disk_key, i); btrfs_node_key(parent, &disk_key, i);
...@@ -1669,7 +1669,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, ...@@ -1669,7 +1669,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
other = btrfs_node_blockptr(parent, i - 1); other = btrfs_node_blockptr(parent, i - 1);
close = close_blocks(blocknr, other, blocksize); close = close_blocks(blocknr, other, blocksize);
} }
if (!close && i < end_slot - 2) { if (!close && i < end_slot) {
other = btrfs_node_blockptr(parent, i + 1); other = btrfs_node_blockptr(parent, i + 1);
close = close_blocks(blocknr, other, blocksize); close = close_blocks(blocknr, other, blocksize);
} }
......
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