btrfs: scrub: cleanup the argument list of scrub_stripe()

The argument list of btrfs_stripe() has similar problems of
scrub_chunk():

- Duplicated and ambiguous @base argument
  Can be fetched from btrfs_block_group::bg.

- Ambiguous argument @length
  It's again device extent length

- Ambiguous argument @num
  The instinctive guess would be mirror number, but in fact it's stripe
  index.

Fix it by:

- Remove @base parameter

- Rename @length to @dev_extent_len

- Rename @num to @stripe_index

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 834a719..2e9a322 100644 (file)
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3166,10 +3166,10 @@ static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical,
 }
 
 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
+                                          struct btrfs_block_group *bg,
                                           struct map_lookup *map,
                                           struct btrfs_device *scrub_dev,
-                                          int num, u64 base, u64 length,
-                                          struct btrfs_block_group *cache)
+                                          int stripe_index, u64 dev_extent_len)
 {
        struct btrfs_path *path;
        struct btrfs_fs_info *fs_info = sctx->fs_info;
@@ -3177,6 +3177,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
        struct btrfs_root *csum_root;
        struct btrfs_extent_item *extent;
        struct blk_plug plug;
+       const u64 chunk_logical = bg->start;
        u64 flags;
        int ret;
        int slot;
@@ -3204,25 +3205,26 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
        int extent_mirror_num;
        int stop_loop = 0;
 
-       physical = map->stripes[num].physical;
+       physical = map->stripes[stripe_index].physical;
        offset = 0;
-       nstripes = div64_u64(length, map->stripe_len);
+       nstripes = div64_u64(dev_extent_len, map->stripe_len);
        mirror_num = 1;
        increment = map->stripe_len;
        if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
-               offset = map->stripe_len * num;
+               offset = map->stripe_len * stripe_index;
                increment = map->stripe_len * map->num_stripes;
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
                int factor = map->num_stripes / map->sub_stripes;
-               offset = map->stripe_len * (num / map->sub_stripes);
+               offset = map->stripe_len * (stripe_index / map->sub_stripes);
                increment = map->stripe_len * factor;
-               mirror_num = num % map->sub_stripes + 1;
+               mirror_num = stripe_index % map->sub_stripes + 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
-               mirror_num = num % map->num_stripes + 1;
+               mirror_num = stripe_index % map->num_stripes + 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-               mirror_num = num % map->num_stripes + 1;
+               mirror_num = stripe_index % map->num_stripes + 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-               get_raid56_logic_offset(physical, num, map, &offset, NULL);
+               get_raid56_logic_offset(physical, stripe_index, map, &offset,
+                                       NULL);
                increment = map->stripe_len * nr_data_stripes(map);
        }
 
@@ -3239,12 +3241,12 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
        path->skip_locking = 1;
        path->reada = READA_FORWARD;
 
-       logical = base + offset;
+       logical = chunk_logical + offset;
        physical_end = physical + nstripes * map->stripe_len;
        if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-               get_raid56_logic_offset(physical_end, num,
+               get_raid56_logic_offset(physical_end, stripe_index,
                                        map, &logic_end, NULL);
-               logic_end += base;
+               logic_end += chunk_logical;
        } else {
                logic_end = logical + increment * nstripes;
        }
@@ -3299,13 +3301,13 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
                }
 
                if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-                       ret = get_raid56_logic_offset(physical, num, map,
-                                                     &logical,
+                       ret = get_raid56_logic_offset(physical, stripe_index,
+                                                     map, &logical,
                                                      &stripe_logical);
-                       logical += base;
+                       logical += chunk_logical;
                        if (ret) {
                                /* it is parity strip */
-                               stripe_logical += base;
+                               stripe_logical += chunk_logical;
                                stripe_end = stripe_logical + increment;
                                ret = scrub_raid56_parity(sctx, map, scrub_dev,
                                                          stripe_logical,
@@ -3385,13 +3387,13 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
                         * Continuing would prevent reusing its device extents
                         * for new block groups for a long time.
                         */
-                       spin_lock(&cache->lock);
-                       if (cache->removed) {
-                               spin_unlock(&cache->lock);
+                       spin_lock(&bg->lock);
+                       if (bg->removed) {
+                               spin_unlock(&bg->lock);
                                ret = 0;
                                goto out;
                        }
-                       spin_unlock(&cache->lock);
+                       spin_unlock(&bg->lock);
 
                        extent = btrfs_item_ptr(l, slot,
                                                struct btrfs_extent_item);
@@ -3470,12 +3472,12 @@ again:
 loop:
                                        physical += map->stripe_len;
                                        ret = get_raid56_logic_offset(physical,
-                                                       num, map, &logical,
-                                                       &stripe_logical);
-                                       logical += base;
+                                                       stripe_index, map,
+                                                       &logical, &stripe_logical);
+                                       logical += chunk_logical;
 
                                        if (ret && physical < physical_end) {
-                                               stripe_logical += base;
+                                               stripe_logical += chunk_logical;
                                                stripe_end = stripe_logical +
                                                                increment;
                                                ret = scrub_raid56_parity(sctx,
@@ -3509,8 +3511,8 @@ skip:
                physical += map->stripe_len;
                spin_lock(&sctx->stat_lock);
                if (stop_loop)
-                       sctx->stat.last_physical = map->stripes[num].physical +
-                                                  length;
+                       sctx->stat.last_physical = map->stripes[stripe_index].physical +
+                                                  dev_extent_len;
                else
                        sctx->stat.last_physical = physical;
                spin_unlock(&sctx->stat_lock);
@@ -3530,9 +3532,10 @@ out:
        if (sctx->is_dev_replace && ret >= 0) {
                int ret2;
 
-               ret2 = sync_write_pointer_for_zoned(sctx, base + offset,
-                                                   map->stripes[num].physical,
-                                                   physical_end);
+               ret2 = sync_write_pointer_for_zoned(sctx,
+                               chunk_logical + offset,
+                               map->stripes[stripe_index].physical,
+                               physical_end);
                if (ret2)
                        ret = ret2;
        }
@@ -3578,8 +3581,8 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
        for (i = 0; i < map->num_stripes; ++i) {
                if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
                    map->stripes[i].physical == dev_offset) {
-                       ret = scrub_stripe(sctx, map, scrub_dev, i,
-                                          bg->start, dev_extent_len, bg);
+                       ret = scrub_stripe(sctx, bg, map, scrub_dev, i,
+                                          dev_extent_len);
                        if (ret)
                                goto out;
                }