Re: [PATCH 1/2] btrfs: Don't search devid for every verify_one_dev_extent() call

[Nikolay Borisov <nborisov@suse.com>]

On 30.01.19 г. 9:39 ч., Qu Wenruo wrote:
> verify_one_dev_extent() will call btrfs_find_device() for each dev
> extent, this waste some CPU time just searching the devices list.
> 
> Move the search one level up, into the btrfs_verify_dev_extents(), so
> for each device we only call btrfs_find_device() once.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Seems the sane thing to do, so:

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>  fs/btrfs/volumes.c | 26 ++++++++++++++++----------
>  1 file changed, 16 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 2576b1a379c9..8e932d7d2fe6 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -7761,13 +7761,14 @@ static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
>  }
>  
>  static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
> -				 u64 chunk_offset, u64 devid,
> -				 u64 physical_offset, u64 physical_len)
> +				 struct btrfs_device *dev,
> +				 u64 chunk_offset, u64 physical_offset,
> +				 u64 physical_len)
>  {
>  	struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
>  	struct extent_map *em;
>  	struct map_lookup *map;
> -	struct btrfs_device *dev;
> +	u64 devid = dev->devid;
>  	u64 stripe_len;
>  	bool found = false;
>  	int ret = 0;
> @@ -7819,12 +7820,6 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
>  	}
>  
>  	/* Make sure no dev extent is beyond device bondary */
> -	dev = btrfs_find_device(fs_info, devid, NULL, NULL);
> -	if (!dev) {
> -		btrfs_err(fs_info, "failed to find devid %llu", devid);
> -		ret = -EUCLEAN;
> -		goto out;
> -	}
>  	if (physical_offset + physical_len > dev->disk_total_bytes) {
>  		btrfs_err(fs_info,
>  "dev extent devid %llu physical offset %llu len %llu is beyond device boundary %llu",
> @@ -7874,6 +7869,7 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
>  {
>  	struct btrfs_path *path;
>  	struct btrfs_root *root = fs_info->dev_root;
> +	struct btrfs_device *device = NULL;
>  	struct btrfs_key key;
>  	u64 prev_devid = 0;
>  	u64 prev_dev_ext_end = 0;
> @@ -7917,6 +7913,16 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
>  		devid = key.objectid;
>  		physical_offset = key.offset;
>  
> +		if (!device || devid != device->devid) {
> +			device = btrfs_find_device(fs_info, devid, NULL, NULL);
> +			if (!device) {
> +				btrfs_err(fs_info, "failed to find devid %llu",
> +					  devid);
> +				ret = -EUCLEAN;
> +				goto out;
> +			}
> +		}
> +
>  		dext = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent);
>  		chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dext);
>  		physical_len = btrfs_dev_extent_length(leaf, dext);
> @@ -7930,7 +7936,7 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
>  			goto out;
>  		}
>  
> -		ret = verify_one_dev_extent(fs_info, chunk_offset, devid,
> +		ret = verify_one_dev_extent(fs_info, device, chunk_offset,
>  					    physical_offset, physical_len);
>  		if (ret < 0)
>  			goto out;
>