4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jeff Mahoney <je...@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 <je...@suse.com>
Signed-off-by: David Sterba <dste...@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchi...@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@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;
