Josef Bacik
2008-Nov-20 16:22 UTC
[PATCH] updated fix for lockdep warnings with alloc_mutex and pinned_mutex
Hello,
This is the updated patch of the one I sent a few weeks ago. It fixes this
lockdep complaint by having a different mutex to gaurd caching the block group,
so you don''t end up with this backwards dependancy. Thank you,
Signed-off-by: Josef Bacik <jbacik@redhat.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index c83cc5b..b3b15ee 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -563,6 +563,7 @@ struct btrfs_block_group_cache {
struct btrfs_block_group_item item;
spinlock_t lock;
struct mutex alloc_mutex;
+ struct mutex cache_mutex;
u64 pinned;
u64 reserved;
u64 flags;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 55d6a66..956fbb1 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -158,8 +158,8 @@ static int add_new_free_space(struct btrfs_block_group_cache
*block_group,
start = extent_end + 1;
} else if (extent_start > start && extent_start < end) {
size = extent_start - start;
- ret = btrfs_add_free_space_lock(block_group, start,
- size);
+ ret = btrfs_add_free_space(block_group, start,
+ size);
BUG_ON(ret);
start = extent_end + 1;
} else {
@@ -169,7 +169,7 @@ static int add_new_free_space(struct btrfs_block_group_cache
*block_group,
if (start < end) {
size = end - start;
- ret = btrfs_add_free_space_lock(block_group, start, size);
+ ret = btrfs_add_free_space(block_group, start, size);
BUG_ON(ret);
}
mutex_unlock(&info->pinned_mutex);
@@ -2177,17 +2177,19 @@ static int noinline find_free_extent(struct
btrfs_trans_handle *trans,
if (!block_group)
goto new_group_no_lock;
+ if (unlikely(!block_group->cached)) {
+ mutex_lock(&block_group->cache_mutex);
+ ret = cache_block_group(root, block_group);
+ mutex_unlock(&block_group->cache_mutex);
+ if (ret)
+ break;
+ }
+
mutex_lock(&block_group->alloc_mutex);
if (unlikely(!block_group_bits(block_group, data)))
goto new_group;
- ret = cache_block_group(root, block_group);
- if (ret) {
- mutex_unlock(&block_group->alloc_mutex);
- break;
- }
-
- if (block_group->ro)
+ if (unlikely(block_group->ro))
goto new_group;
free_space = btrfs_find_free_space(block_group, search_start,
@@ -2604,12 +2606,12 @@ int btrfs_alloc_logged_extent(struct btrfs_trans_handle
*trans,
struct btrfs_block_group_cache *block_group;
block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
- mutex_lock(&block_group->alloc_mutex);
+ mutex_lock(&block_group->cache_mutex);
cache_block_group(root, block_group);
+ mutex_unlock(&block_group->cache_mutex);
- ret = btrfs_remove_free_space_lock(block_group, ins->objectid,
- ins->offset);
- mutex_unlock(&block_group->alloc_mutex);
+ ret = btrfs_remove_free_space(block_group, ins->objectid,
+ ins->offset);
BUG_ON(ret);
ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
ref_generation, owner, ins);
@@ -5132,6 +5134,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
spin_lock_init(&cache->lock);
mutex_init(&cache->alloc_mutex);
+ mutex_init(&cache->cache_mutex);
INIT_LIST_HEAD(&cache->list);
read_extent_buffer(leaf, &cache->item,
btrfs_item_ptr_offset(leaf, path->slots[0]),
@@ -5183,6 +5186,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle
*trans,
cache->key.offset = size;
spin_lock_init(&cache->lock);
mutex_init(&cache->alloc_mutex);
+ mutex_init(&cache->cache_mutex);
INIT_LIST_HEAD(&cache->list);
btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
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