Re: [PATCH v6 5/6] Btrfs: rename get_chunk_map() and make it non-static

[Nikolay Borisov <nborisov@suse.com>]

On  7.09.2018 10:39, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> The Btrfs swap code is going to need it, so give it a btrfs_ prefix and
> make it non-static.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>

One minor nit but otherwise:

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

> ---
>  fs/btrfs/volumes.c | 22 +++++++++++-----------
>  fs/btrfs/volumes.h |  9 +++++++++
>  2 files changed, 20 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 207e36b70d9b..514932c47bcd 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -2714,8 +2714,8 @@ static int btrfs_del_sys_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
>  	return ret;
>  }
>  
> -static struct extent_map *get_chunk_map(struct btrfs_fs_info *fs_info,
> -					u64 logical, u64 length)
> +struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
> +				       u64 logical, u64 length)
>  {
>  	struct extent_map_tree *em_tree;
>  	struct extent_map *em;
> @@ -2752,7 +2752,7 @@ int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)
>  	int i, ret = 0;
>  	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
>  
> -	em = get_chunk_map(fs_info, chunk_offset, 1);
> +	em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
>  	if (IS_ERR(em)) {
>  		/*
>  		 * This is a logic error, but we don't want to just rely on the
> @@ -4897,7 +4897,7 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
>  	int i = 0;
>  	int ret = 0;
>  
> -	em = get_chunk_map(fs_info, chunk_offset, chunk_size);
> +	em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
>  	if (IS_ERR(em))
>  		return PTR_ERR(em);
>  
> @@ -5039,7 +5039,7 @@ int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset)
>  	int miss_ndevs = 0;
>  	int i;
>  
> -	em = get_chunk_map(fs_info, chunk_offset, 1);
> +	em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
>  	if (IS_ERR(em))
>  		return 1;
>  
> @@ -5099,7 +5099,7 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
>  	struct map_lookup *map;
>  	int ret;
>  
> -	em = get_chunk_map(fs_info, logical, len);
> +	em = btrfs_get_chunk_map(fs_info, logical, len);
>  	if (IS_ERR(em))
>  		/*
>  		 * We could return errors for these cases, but that could get
> @@ -5145,7 +5145,7 @@ unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
>  	struct map_lookup *map;
>  	unsigned long len = fs_info->sectorsize;
>  
> -	em = get_chunk_map(fs_info, logical, len);
> +	em = btrfs_get_chunk_map(fs_info, logical, len);
>  
>  	if (!WARN_ON(IS_ERR(em))) {
>  		map = em->map_lookup;
> @@ -5162,7 +5162,7 @@ int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
>  	struct map_lookup *map;
>  	int ret = 0;
>  
> -	em = get_chunk_map(fs_info, logical, len);
> +	em = btrfs_get_chunk_map(fs_info, logical, len);
>  
>  	if(!WARN_ON(IS_ERR(em))) {
>  		map = em->map_lookup;
> @@ -5321,7 +5321,7 @@ static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info,
>  	/* discard always return a bbio */
>  	ASSERT(bbio_ret);
>  
> -	em = get_chunk_map(fs_info, logical, length);
> +	em = btrfs_get_chunk_map(fs_info, logical, length);
>  	if (IS_ERR(em))
>  		return PTR_ERR(em);
>  
> @@ -5647,7 +5647,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
>  		return __btrfs_map_block_for_discard(fs_info, logical,
>  						     *length, bbio_ret);
>  
> -	em = get_chunk_map(fs_info, logical, *length);
> +	em = btrfs_get_chunk_map(fs_info, logical, *length);
>  	if (IS_ERR(em))
>  		return PTR_ERR(em);
>  
> @@ -5946,7 +5946,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
>  	u64 rmap_len;
>  	int i, j, nr = 0;
>  
> -	em = get_chunk_map(fs_info, chunk_start, 1);
> +	em = btrfs_get_chunk_map(fs_info, chunk_start, 1);
>  	if (IS_ERR(em))
>  		return -EIO;
>  
> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
> index 23e9285d88de..d68c8a05a774 100644
> --- a/fs/btrfs/volumes.h
> +++ b/fs/btrfs/volumes.h
> @@ -465,6 +465,15 @@ unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
>  int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
>  			     u64 chunk_offset, u64 chunk_size);
>  int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
> +/**
> + * btrfs_get_chunk_map() - Find the mapping containing the given logical extent.
> + * @logical: Logical block offset in bytes.
> + * @length: Length of extent in bytes.
> + *
> + * Return: Chunk mapping or ERR_PTR.
> + */

nit: I think the accepted style is to have the documentation before the
definition and not declaration of the function. I guess David can fix
that when the patch is being merged.

> +struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
> +				       u64 logical, u64 length);
>  
>  static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
>  				      int index)
>