4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jeff Mahoney jeffm@suse.com
commit 95617d69326ce386c95e33db7aeb832b45ee9f8f upstream.
Overloading extent_map->bdev to struct map_lookup * might have started out as a means to an end, but it's a pattern that's used all over the place now. Let's get rid of the casting and just add a union instead.
Signed-off-by: Jeff Mahoney jeffm@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/dev-replace.c | 2 +- fs/btrfs/extent-tree.c | 2 +- fs/btrfs/extent_map.c | 2 +- fs/btrfs/extent_map.h | 10 +++++++++- fs/btrfs/scrub.c | 2 +- fs/btrfs/volumes.c | 24 ++++++++++++------------ 6 files changed, 25 insertions(+), 17 deletions(-)
--- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -620,7 +620,7 @@ static void btrfs_dev_replace_update_dev em = lookup_extent_mapping(em_tree, start, (u64)-1); if (!em) break; - map = (struct map_lookup *)em->bdev; + map = em->map_lookup; for (i = 0; i < map->num_stripes; i++) if (srcdev == map->stripes[i].dev) map->stripes[i].dev = tgtdev; --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -10388,7 +10388,7 @@ btrfs_start_trans_remove_block_group(str * more device items and remove one chunk item), but this is done at * btrfs_remove_chunk() through a call to check_system_chunk(). */ - map = (struct map_lookup *)em->bdev; + map = em->map_lookup; num_items = 3 + map->num_stripes; free_extent_map(em);
--- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -76,7 +76,7 @@ void free_extent_map(struct extent_map * WARN_ON(extent_map_in_tree(em)); WARN_ON(!list_empty(&em->list)); if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags)) - kfree(em->bdev); + kfree(em->map_lookup); kmem_cache_free(extent_map_cache, em); } } --- a/fs/btrfs/extent_map.h +++ b/fs/btrfs/extent_map.h @@ -32,7 +32,15 @@ struct extent_map { u64 block_len; u64 generation; unsigned long flags; - struct block_device *bdev; + union { + struct block_device *bdev; + + /* + * used for chunk mappings + * flags & EXTENT_FLAG_FS_MAPPING must be set + */ + struct map_lookup *map_lookup; + }; atomic_t refs; unsigned int compress_type; struct list_head list; --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -3460,7 +3460,7 @@ static noinline_for_stack int scrub_chun return ret; }
- map = (struct map_lookup *)em->bdev; + map = em->map_lookup; if (em->start != chunk_offset) goto out;
--- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1184,7 +1184,7 @@ again: struct map_lookup *map; int i;
- map = (struct map_lookup *)em->bdev; + map = em->map_lookup; for (i = 0; i < map->num_stripes; i++) { u64 end;
@@ -2757,7 +2757,7 @@ int btrfs_remove_chunk(struct btrfs_tran free_extent_map(em); return -EINVAL; } - map = (struct map_lookup *)em->bdev; + map = em->map_lookup; lock_chunks(root->fs_info->chunk_root); check_system_chunk(trans, extent_root, map->type); unlock_chunks(root->fs_info->chunk_root); @@ -4731,7 +4731,7 @@ static int __btrfs_alloc_chunk(struct bt goto error; } set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags); - em->bdev = (struct block_device *)map; + em->map_lookup = map; em->start = start; em->len = num_bytes; em->block_start = 0; @@ -4826,7 +4826,7 @@ int btrfs_finish_chunk_alloc(struct btrf return -EINVAL; }
- map = (struct map_lookup *)em->bdev; + map = em->map_lookup; item_size = btrfs_chunk_item_size(map->num_stripes); stripe_size = em->orig_block_len;
@@ -4968,7 +4968,7 @@ int btrfs_chunk_readonly(struct btrfs_ro if (!em) return 1;
- map = (struct map_lookup *)em->bdev; + map = em->map_lookup; for (i = 0; i < map->num_stripes; i++) { if (map->stripes[i].dev->missing) { miss_ndevs++; @@ -5048,7 +5048,7 @@ int btrfs_num_copies(struct btrfs_fs_inf return 1; }
- map = (struct map_lookup *)em->bdev; + map = em->map_lookup; if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1)) ret = map->num_stripes; else if (map->type & BTRFS_BLOCK_GROUP_RAID10) @@ -5091,7 +5091,7 @@ unsigned long btrfs_full_stripe_len(stru BUG_ON(!em);
BUG_ON(em->start > logical || em->start + em->len < logical); - map = (struct map_lookup *)em->bdev; + map = em->map_lookup; if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) len = map->stripe_len * nr_data_stripes(map); free_extent_map(em); @@ -5112,7 +5112,7 @@ int btrfs_is_parity_mirror(struct btrfs_ BUG_ON(!em);
BUG_ON(em->start > logical || em->start + em->len < logical); - map = (struct map_lookup *)em->bdev; + map = em->map_lookup; if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) ret = 1; free_extent_map(em); @@ -5271,7 +5271,7 @@ static int __btrfs_map_block(struct btrf return -EINVAL; }
- map = (struct map_lookup *)em->bdev; + map = em->map_lookup; offset = logical - em->start;
stripe_len = map->stripe_len; @@ -5813,7 +5813,7 @@ int btrfs_rmap_block(struct btrfs_mappin free_extent_map(em); return -EIO; } - map = (struct map_lookup *)em->bdev; + map = em->map_lookup;
length = em->len; rmap_len = map->stripe_len; @@ -6249,7 +6249,7 @@ static int read_one_chunk(struct btrfs_r }
set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags); - em->bdev = (struct block_device *)map; + em->map_lookup = map; em->start = logical; em->len = length; em->orig_start = 0; @@ -6948,7 +6948,7 @@ void btrfs_update_commit_device_bytes_us /* In order to kick the device replace finish process */ lock_chunks(root); list_for_each_entry(em, &transaction->pending_chunks, list) { - map = (struct map_lookup *)em->bdev; + map = em->map_lookup;
for (i = 0; i < map->num_stripes; i++) { dev = map->stripes[i].dev;