btrfs: remove the need_raid_map parameter from btrfs_map_block()

The parameter @need_raid_map is mostly a legacy from the old days where
we don't yet have a solid definition on the @mirror_num, and only
check-integrity was using that parameter, while all other call sites
just pass 1 for that parameter.

Now since we have removed check-integrity functionality, we can also
remove the @need_raid_map parameter.

This change will also remove the ability to read P/Q stripe directly
when passing 0 as @need_raid_map.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/bio.c

@@ -656,7 +656,7 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
 
 	btrfs_bio_counter_inc_blocked(fs_info);
 	error = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
-				&bioc, &smap, &mirror_num, 1);
+				&bioc, &smap, &mirror_num);
 	if (error) {
 		ret = errno_to_blk_status(error);
 		goto fail;

fs/btrfs/scrub.c

@@ -896,7 +896,7 @@ static void scrub_stripe_report_errors(struct scrub_ctx *sctx,
 		ASSERT(stripe->mirror_num >= 1);
 		ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
 				      stripe->logical, &mapped_len, &bioc,
-				      NULL, NULL, 1);
+				      NULL, NULL);
 		/*
 		 * If we failed, dev will be NULL, and later detailed reports
 		 * will just be skipped.
@@ -1951,7 +1951,7 @@ static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx,
 
 	btrfs_bio_counter_inc_blocked(fs_info);
 	ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, full_stripe_start,
-			      &length, &bioc, NULL, NULL, 1);
+			      &length, &bioc, NULL, NULL);
 	if (ret < 0) {
 		btrfs_put_bioc(bioc);
 		btrfs_bio_counter_dec(fs_info);

fs/btrfs/volumes.c

@@ -6246,16 +6246,11 @@ static void set_io_stripe(struct btrfs_io_stripe *dst, const struct map_lookup *
  *			For RAID6 profile, mirror > 2 means mark another
  *			data/P stripe error and rebuild from the remaining
  *			stripes..
- *
- * @need_raid_map:	(Used only for integrity checker) whether the map wants
- *                      a full stripe map (including all data and P/Q stripes)
- *                      for RAID56. Should always be 1 except integrity checker.
  */
 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		    u64 logical, u64 *length,
 		    struct btrfs_io_context **bioc_ret,
-		    struct btrfs_io_stripe *smap, int *mirror_num_ret,
-		    int need_raid_map)
+		    struct btrfs_io_stripe *smap, int *mirror_num_ret)
 {
 	struct extent_map *em;
 	struct map_lookup *map;
@@ -6350,8 +6345,10 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		}
 
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-		if (need_raid_map && (op != BTRFS_MAP_READ || mirror_num > 1)) {
+		if (op != BTRFS_MAP_READ || mirror_num > 1) {
 			/*
+			 * Needs full stripe mapping.
+			 *
 			 * Push stripe_nr back to the start of the full stripe
 			 * For those cases needing a full stripe, @stripe_nr
 			 * is the full stripe number.
@@ -6374,19 +6371,14 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 			stripe_index = 0;
 			stripe_offset = 0;
 		} else {
-			/*
-			 * Mirror #0 or #1 means the original data block.
-			 * Mirror #2 is RAID5 parity block.
-			 * Mirror #3 is RAID6 Q block.
-			 */
+			ASSERT(mirror_num <= 1);
+			/* Just grab the data stripe directly. */
 			stripe_index = stripe_nr % data_stripes;
 			stripe_nr /= data_stripes;
-			if (mirror_num > 1)
-				stripe_index = data_stripes + mirror_num - 2;
 
 			/* We distribute the parity blocks across stripes */
 			stripe_index = (stripe_nr + stripe_index) % map->num_stripes;
-			if (op == BTRFS_MAP_READ && mirror_num <= 1)
+			if (op == BTRFS_MAP_READ && mirror_num < 1)
 				mirror_num = 1;
 		}
 	} else {
@@ -6448,7 +6440,7 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	 *
 	 * It's still mostly the same as other profiles, just with extra rotation.
 	 */
-	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && need_raid_map &&
+	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK &&
 	    (op != BTRFS_MAP_READ || mirror_num > 1)) {
 		/*
 		 * For RAID56 @stripe_nr is already the number of full stripes
@@ -8077,7 +8069,7 @@ int btrfs_map_repair_block(struct btrfs_fs_info *fs_info,
 	ASSERT(mirror_num > 0);
 
 	ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical, &map_length,
-			      &bioc, smap, &mirror_ret, true);
+			      &bioc, smap, &mirror_ret);
 	if (ret < 0)
 		return ret;
 

fs/btrfs/volumes.h

@@ -605,8 +605,7 @@ void btrfs_put_bioc(struct btrfs_io_context *bioc);
 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		    u64 logical, u64 *length,
 		    struct btrfs_io_context **bioc_ret,
-		    struct btrfs_io_stripe *smap, int *mirror_num_ret,
-		    int need_raid_map);
+		    struct btrfs_io_stripe *smap, int *mirror_num_ret);
 int btrfs_map_repair_block(struct btrfs_fs_info *fs_info,
 			   struct btrfs_io_stripe *smap, u64 logical,
 			   u32 length, int mirror_num);

fs/btrfs/zoned.c

@@ -1887,7 +1887,7 @@ static int read_zone_info(struct btrfs_fs_info *fs_info, u64 logical,
 	int i, ret;
 
 	ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
-			      &mapped_length, &bioc, NULL, NULL, 1);
+			      &mapped_length, &bioc, NULL, NULL);
 	if (ret || !bioc || mapped_length < PAGE_SIZE) {
 		ret = -EIO;
 		goto out_put_bioc;