btrfs: cleanup, stop casting for extent_map->lookup everywhere

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>

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 1e668fb..cbb7dbf 100644 (file)
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -614,7 +614,7 @@ static void btrfs_dev_replace_update_device_in_mapping_tree(
                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;

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1ea56d8..8c91289 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -10322,7 +10322,7 @@ btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
         * 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);
 

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 6a98bdd..84fb56d 100644 (file)
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -76,7 +76,7 @@ void free_extent_map(struct extent_map *em)
                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);
        }
 }

diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index b2991fd..eb8b8fa 100644 (file)
--- 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;

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index b57a15a..151000f 100644 (file)
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3458,7 +3458,7 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
                return ret;
        }
 
-       map = (struct map_lookup *)em->bdev;
+       map = em->map_lookup;
        if (em->start != chunk_offset)
                goto out;
 

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index adb79ad..9cb78e3 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1182,7 +1182,7 @@ 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;
 
@@ -2754,7 +2754,7 @@ int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
                        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);
@@ -4718,7 +4718,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                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;
@@ -4813,7 +4813,7 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
                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;
 
@@ -4955,7 +4955,7 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
        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++;
@@ -5035,7 +5035,7 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
                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)
@@ -5071,7 +5071,7 @@ unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
        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);
@@ -5092,7 +5092,7 @@ int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
        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);
@@ -5251,7 +5251,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
                return -EINVAL;
        }
 
-       map = (struct map_lookup *)em->bdev;
+       map = em->map_lookup;
        offset = logical - em->start;
 
        stripe_len = map->stripe_len;
@@ -5793,7 +5793,7 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
                free_extent_map(em);
                return -EIO;
        }
-       map = (struct map_lookup *)em->bdev;
+       map = em->map_lookup;
 
        length = em->len;
        rmap_len = map->stripe_len;
@@ -6229,7 +6229,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
        }
 
        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;
@@ -6920,7 +6920,7 @@ void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
        /* 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;