[PATCH 08/10] btrfs: simplify conditions in btrfs_free_chunk_map()

David Sterba
2024-02-19T11:13:40Z

The helper is simple enough for inlining, we can further simplify it by
removing the check for map pointer validity. After this patch all
callers always pass a valid pointer.

The changes to achieve this:

- in verify_one_dev_extent() return and don't jump to the out label
that could potentially pass a NULL pointer to btrfs_free_chunk_map

- in btrfs_load_block_group_zone_info() add a label that specifically
clears the map and does not go through label out that could encounter
a NULL pointer in cache->physical_map

Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/volumes.c | 3 +--
fs/btrfs/volumes.h | 2 +-
fs/btrfs/zoned.c | 3 ++-
3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 752144a31d79..55b91807aba4 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -7979,8 +7979,7 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
btrfs_err(fs_info,
"dev extent physical offset %llu on devid %llu doesn't have corresponding chunk",
physical_offset, devid);
- ret = -EUCLEAN;
- goto out;
+ return -EUCLEAN;
}

stripe_len = btrfs_calc_stripe_length(map);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 21d4de0e3f1f..ce1aa7684c74 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -566,7 +566,7 @@ struct btrfs_chunk_map {

static inline void btrfs_free_chunk_map(struct btrfs_chunk_map *map)
{
- if (map && refcount_dec_and_test(&map->refs)) {
+ if (refcount_dec_and_test(&map->refs)) {
ASSERT(RB_EMPTY_NODE(&map->rb_node));
kfree(map);
}
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 3317bebfca95..b9346ca82c47 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1564,7 +1564,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
cache->physical_map = btrfs_clone_chunk_map(map, GFP_NOFS);
if (!cache->physical_map) {
ret = -ENOMEM;
- goto out;
+ goto out_free_map;
}

zone_info = kcalloc(map->num_stripes, sizeof(*zone_info), GFP_NOFS);
@@ -1677,6 +1677,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
}
bitmap_free(active);
kfree(zone_info);
+out_free_map:
btrfs_free_chunk_map(map);

return ret;
--
2.42.1