btrfs: use for-local variables that shadow function variables

We've started to use for-loop local variables and in a few places this
shadows a function variable. Convert a few cases reported by 'make W=2'.
If applicable also change the style to post-increment, that's the
preferred one.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/qgroup.c

@@ -3222,7 +3222,6 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 			 struct btrfs_qgroup_inherit *inherit)
 {
 	int ret = 0;
-	int i;
 	u64 *i_qgroups;
 	bool committing = false;
 	struct btrfs_fs_info *fs_info = trans->fs_info;
@@ -3279,7 +3278,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 		i_qgroups = (u64 *)(inherit + 1);
 		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
 		       2 * inherit->num_excl_copies;
-		for (i = 0; i < nums; ++i) {
+		for (int i = 0; i < nums; i++) {
 			srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
 
 			/*
@@ -3306,7 +3305,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 	 */
 	if (inherit) {
 		i_qgroups = (u64 *)(inherit + 1);
-		for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
+		for (int i = 0; i < inherit->num_qgroups; i++, i_qgroups++) {
 			if (*i_qgroups == 0)
 				continue;
 			ret = add_qgroup_relation_item(trans, objectid,
@@ -3392,7 +3391,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 		goto unlock;
 
 	i_qgroups = (u64 *)(inherit + 1);
-	for (i = 0; i < inherit->num_qgroups; ++i) {
+	for (int i = 0; i < inherit->num_qgroups; i++) {
 		if (*i_qgroups) {
 			ret = add_relation_rb(fs_info, qlist_prealloc[i], objectid,
 					      *i_qgroups);
@@ -3412,7 +3411,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 		++i_qgroups;
 	}
 
-	for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
+	for (int i = 0; i < inherit->num_ref_copies; i++, i_qgroups += 2) {
 		struct btrfs_qgroup *src;
 		struct btrfs_qgroup *dst;
 
@@ -3433,7 +3432,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 		/* Manually tweaking numbers certainly needs a rescan */
 		need_rescan = true;
 	}
-	for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
+	for (int i = 0; i < inherit->num_excl_copies; i++, i_qgroups += 2) {
 		struct btrfs_qgroup *src;
 		struct btrfs_qgroup *dst;
 

fs/btrfs/volumes.c

@@ -5626,8 +5626,6 @@ static struct btrfs_block_group *create_chunk(struct btrfs_trans_handle *trans,
 	u64 start = ctl->start;
 	u64 type = ctl->type;
 	int ret;
-	int i;
-	int j;
 
 	map = btrfs_alloc_chunk_map(ctl->num_stripes, GFP_NOFS);
 	if (!map)
@@ -5642,8 +5640,8 @@ static struct btrfs_block_group *create_chunk(struct btrfs_trans_handle *trans,
 	map->sub_stripes = ctl->sub_stripes;
 	map->num_stripes = ctl->num_stripes;
 
-	for (i = 0; i < ctl->ndevs; ++i) {
-		for (j = 0; j < ctl->dev_stripes; ++j) {
+	for (int i = 0; i < ctl->ndevs; i++) {
+		for (int j = 0; j < ctl->dev_stripes; j++) {
 			int s = i * ctl->dev_stripes + j;
 			map->stripes[s].dev = devices_info[i].dev;
 			map->stripes[s].physical = devices_info[i].dev_offset +
@@ -6621,7 +6619,6 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	struct btrfs_chunk_map *map;
 	struct btrfs_io_geometry io_geom = { 0 };
 	u64 map_offset;
-	int i;
 	int ret = 0;
 	int num_copies;
 	struct btrfs_io_context *bioc = NULL;
@@ -6767,7 +6764,7 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		 * For all other non-RAID56 profiles, just copy the target
 		 * stripe into the bioc.
 		 */
-		for (i = 0; i < io_geom.num_stripes; i++) {
+		for (int i = 0; i < io_geom.num_stripes; i++) {
 			ret = set_io_stripe(fs_info, logical, length,
 					    &bioc->stripes[i], map, &io_geom);
 			if (ret < 0)

fs/btrfs/zoned.c

@@ -87,9 +87,8 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
 	bool empty[BTRFS_NR_SB_LOG_ZONES];
 	bool full[BTRFS_NR_SB_LOG_ZONES];
 	sector_t sector;
-	int i;
 
-	for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
+	for (int i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
 		ASSERT(zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL);
 		empty[i] = (zones[i].cond == BLK_ZONE_COND_EMPTY);
 		full[i] = sb_zone_is_full(&zones[i]);
@@ -121,9 +120,8 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
 		struct address_space *mapping = bdev->bd_mapping;
 		struct page *page[BTRFS_NR_SB_LOG_ZONES];
 		struct btrfs_super_block *super[BTRFS_NR_SB_LOG_ZONES];
-		int i;
 
-		for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
+		for (int i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
 			u64 zone_end = (zones[i].start + zones[i].capacity) << SECTOR_SHIFT;
 			u64 bytenr = ALIGN_DOWN(zone_end, BTRFS_SUPER_INFO_SIZE) -
 						BTRFS_SUPER_INFO_SIZE;
@@ -144,7 +142,7 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
 		else
 			sector = zones[0].start;
 
-		for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++)
+		for (int i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++)
 			btrfs_release_disk_super(super[i]);
 	} else if (!full[0] && (empty[1] || full[1])) {
 		sector = zones[0].wp;