Re: [PATCH] Btrfs: fill_holes: Fix slot number passed to hole_mergeable() call.

[Wang Shilong <wangsl.fnst@cn.fujitsu.com>]

On 07/01/2014 02:34 PM, Chandan Rajendra wrote:
> For a non-existent key, btrfs_search_slot() sets path->slots[0] to the slot
> where the key could have been present, which in this case would be the slot
> containing the extent item which would be the next neighbor of the file range
> being punched. The current code passes an incremented path->slots[0] and we
> skip to the wrong file extent item. This would mean that we would fail to
> merge the "yet to be created" hole with the next neighboring hole (if one
> exists). Fix this.
>
> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
> ---
Nice catch, this looks good to me.

Reviewed-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>

>   fs/btrfs/file.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> index ad7c059..3cd7997 100644
> --- a/fs/btrfs/file.c
> +++ b/fs/btrfs/file.c
> @@ -2126,10 +2126,9 @@ static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
>   		goto out;
>   	}
>   
> -	if (hole_mergeable(inode, leaf, path->slots[0]+1, offset, end)) {
> +	if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
>   		u64 num_bytes;
>   
> -		path->slots[0]++;
>   		key.offset = offset;
>   		btrfs_set_item_key_safe(root, path, &key);
>   		fi = btrfs_item_ptr(leaf, path->slots[0],