btrfs: remove the mirror_num argument to btrfs_submit_compressed_read

Given that read recovery for data I/O is handled in the storage layer,
the mirror_num argument to btrfs_submit_compressed_read is always 0,
so remove it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/compression.c

@@ -472,7 +472,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
  * After the compressed pages are read, we copy the bytes into the
  * bio we were passed and then call the bio end_io calls
  */
-void btrfs_submit_compressed_read(struct btrfs_bio *bbio, int mirror_num)
+void btrfs_submit_compressed_read(struct btrfs_bio *bbio)
 {
 	struct btrfs_inode *inode = bbio->inode;
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
@@ -538,7 +538,7 @@ void btrfs_submit_compressed_read(struct btrfs_bio *bbio, int mirror_num)
 	if (memstall)
 		psi_memstall_leave(&pflags);
 
-	btrfs_submit_bio(&cb->bbio, mirror_num);
+	btrfs_submit_bio(&cb->bbio, 0);
 	return;
 
 out_free_compressed_pages:

fs/btrfs/compression.h

@@ -93,7 +93,7 @@ void btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 				  unsigned int nr_pages,
 				  blk_opf_t write_flags,
 				  bool writeback);
-void btrfs_submit_compressed_read(struct btrfs_bio *bbio, int mirror_num);
+void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
 
 unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
 

fs/btrfs/extent_io.c

@@ -126,7 +126,7 @@ static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
 
 	if (btrfs_op(&bbio->bio) == BTRFS_MAP_READ &&
 	    bio_ctrl->compress_type != BTRFS_COMPRESS_NONE)
-		btrfs_submit_compressed_read(bbio, 0);
+		btrfs_submit_compressed_read(bbio);
 	else
 		btrfs_submit_bio(bbio, 0);