btrfs: rename btrfs_io_stripe::is_scrub to rst_search_commit_root

Rename 'btrfs_io_stripe::is_scrub' to 'rst_search_commit_root'. While
'is_scrub' describes the state of the io_stripe (it is a stripe submitted
by scrub) it does not describe the purpose, namely looking at the commit
root when searching RAID stripe-tree entries.

Renaming the stripe to rst_search_commit_root describes this purpose.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/bio.c

@@ -678,7 +678,7 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
 	blk_status_t ret;
 	int error;
 
-	smap.is_scrub = !bbio->inode;
+	smap.rst_search_commit_root = !bbio->inode;
 
 	btrfs_bio_counter_inc_blocked(fs_info);
 	error = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,

fs/btrfs/raid-stripe-tree.c

@@ -210,7 +210,7 @@ int btrfs_get_raid_extent_offset(struct btrfs_fs_info *fs_info,
 	if (!path)
 		return -ENOMEM;
 
-	if (stripe->is_scrub) {
+	if (stripe->rst_search_commit_root) {
 		path->skip_locking = 1;
 		path->search_commit_root = 1;
 	}
@@ -283,7 +283,7 @@ int btrfs_get_raid_extent_offset(struct btrfs_fs_info *fs_info,
 out:
 	if (ret > 0)
 		ret = -ENOENT;
-	if (ret && ret != -EIO && !stripe->is_scrub) {
+	if (ret && ret != -EIO && !stripe->rst_search_commit_root) {
 		btrfs_err(fs_info,
 		"cannot find raid-stripe for logical [%llu, %llu] devid %llu, profile %s",
 			  logical, logical + *length, stripe->dev->devid,

fs/btrfs/scrub.c

@@ -1694,7 +1694,7 @@ static void scrub_submit_extent_sector_read(struct scrub_ctx *sctx,
 					    (i << fs_info->sectorsize_bits);
 			int err;
 
-			io_stripe.is_scrub = true;
+			io_stripe.rst_search_commit_root = true;
 			stripe_len = (nr_sectors - i) << fs_info->sectorsize_bits;
 			/*
 			 * For RST cases, we need to manually split the bbio to

fs/btrfs/volumes.h

@@ -444,7 +444,7 @@ struct btrfs_io_stripe {
 	/* Block mapping. */
 	u64 physical;
 	u64 length;
-	bool is_scrub;
+	bool rst_search_commit_root;
 	/* For the endio handler. */
 	struct btrfs_io_context *bioc;
 };