Re: [PATCH v12 20/41] btrfs: use bio_add_zone_append_page for zoned btrfs

[Josef Bacik <josef@toxicpanda.com>]

On 1/15/21 1:53 AM, Naohiro Aota wrote:
> Zoned device has its own hardware restrictions e.g. max_zone_append_size
> when using REQ_OP_ZONE_APPEND. To follow the restrictions, use
> bio_add_zone_append_page() instead of bio_add_page(). We need target device
> to use bio_add_zone_append_page(), so this commit reads the chunk
> information to memoize the target device to btrfs_io_bio(bio)->device.
> 
> Currently, zoned btrfs only supports SINGLE profile. In the feature,
> btrfs_io_bio can hold extent_map and check the restrictions for all the
> devices the bio will be mapped.
> 
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/extent_io.c | 30 +++++++++++++++++++++++++++---
>   1 file changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 96f43b9121d6..41fccfbaee15 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -3083,6 +3083,7 @@ static bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
>   {
>   	sector_t sector = logical >> SECTOR_SHIFT;
>   	bool contig;
> +	int ret;
>   
>   	if (prev_bio_flags != bio_flags)
>   		return false;
> @@ -3097,7 +3098,12 @@ static bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
>   	if (btrfs_bio_fits_in_stripe(page, size, bio, bio_flags))
>   		return false;
>   
> -	return bio_add_page(bio, page, size, pg_offset) == size;
> +	if (bio_op(bio) == REQ_OP_ZONE_APPEND)
> +		ret = bio_add_zone_append_page(bio, page, size, pg_offset);
> +	else
> +		ret = bio_add_page(bio, page, size, pg_offset);
> +
> +	return ret == size;
>   }
>   
>   /*
> @@ -3128,7 +3134,9 @@ static int submit_extent_page(unsigned int opf,
>   	int ret = 0;
>   	struct bio *bio;
>   	size_t io_size = min_t(size_t, size, PAGE_SIZE);
> -	struct extent_io_tree *tree = &BTRFS_I(page->mapping->host)->io_tree;
> +	struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
> +	struct extent_io_tree *tree = &inode->io_tree;
> +	struct btrfs_fs_info *fs_info = inode->root->fs_info;
>   
>   	ASSERT(bio_ret);
>   
> @@ -3159,11 +3167,27 @@ static int submit_extent_page(unsigned int opf,
>   	if (wbc) {
>   		struct block_device *bdev;
>   
> -		bdev = BTRFS_I(page->mapping->host)->root->fs_info->fs_devices->latest_bdev;
> +		bdev = fs_info->fs_devices->latest_bdev;
>   		bio_set_dev(bio, bdev);
>   		wbc_init_bio(wbc, bio);
>   		wbc_account_cgroup_owner(wbc, page, io_size);
>   	}
> +	if (btrfs_is_zoned(fs_info) &&
> +	    bio_op(bio) == REQ_OP_ZONE_APPEND) {
> +		struct extent_map *em;
> +		struct map_lookup *map;
> +
> +		em = btrfs_get_chunk_map(fs_info, offset, io_size);

Same goes for this, it fails to compile on misc-next.  Thanks,

Josef