diff options
Diffstat (limited to 'fs/btrfs/extent-tree.c')
-rw-r--r-- | fs/btrfs/extent-tree.c | 85 |
1 files changed, 56 insertions, 29 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index b003b43..58bceee 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2333,8 +2333,6 @@ static int noinline drop_leaf_ref_no_cache(struct btrfs_trans_handle *trans, leaf_owner = btrfs_header_owner(leaf); leaf_generation = btrfs_header_generation(leaf); - mutex_unlock(&root->fs_info->alloc_mutex); - for (i = 0; i < nritems; i++) { u64 disk_bytenr; cond_resched(); @@ -2362,8 +2360,6 @@ static int noinline drop_leaf_ref_no_cache(struct btrfs_trans_handle *trans, mutex_unlock(&root->fs_info->alloc_mutex); BUG_ON(ret); } - - mutex_lock(&root->fs_info->alloc_mutex); return 0; } @@ -2375,7 +2371,6 @@ static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans, int ret; struct btrfs_extent_info *info = ref->extents; - mutex_unlock(&root->fs_info->alloc_mutex); for (i = 0; i < ref->nritems; i++) { mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_free_extent(trans, root, @@ -2386,7 +2381,6 @@ static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans, BUG_ON(ret); info++; } - mutex_lock(&root->fs_info->alloc_mutex); return 0; } @@ -2440,10 +2434,39 @@ int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len, u32 *refs) { int ret; - mutex_unlock(&root->fs_info->alloc_mutex); + ret = lookup_extent_ref(NULL, root, start, len, refs); + BUG_ON(ret); + +#if 0 // some debugging code in case we see problems here + /* if the refs count is one, it won't get increased again. But + * if the ref count is > 1, someone may be decreasing it at + * the same time we are. + */ + if (*refs != 1) { + struct extent_buffer *eb = NULL; + eb = btrfs_find_create_tree_block(root, start, len); + if (eb) + btrfs_tree_lock(eb); + + mutex_lock(&root->fs_info->alloc_mutex); + ret = lookup_extent_ref(NULL, root, start, len, refs); + BUG_ON(ret); + mutex_unlock(&root->fs_info->alloc_mutex); + + if (eb) { + btrfs_tree_unlock(eb); + free_extent_buffer(eb); + } + if (*refs == 1) { + printk("block %llu went down to one during drop_snap\n", + (unsigned long long)start); + } + + } +#endif + cond_resched(); - mutex_lock(&root->fs_info->alloc_mutex); return ret; } @@ -2467,8 +2490,6 @@ static int noinline walk_down_tree(struct btrfs_trans_handle *trans, int ret; u32 refs; - mutex_lock(&root->fs_info->alloc_mutex); - WARN_ON(*level < 0); WARN_ON(*level >= BTRFS_MAX_LEVEL); ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start, @@ -2507,13 +2528,21 @@ static int noinline walk_down_tree(struct btrfs_trans_handle *trans, root_owner = btrfs_header_owner(parent); root_gen = btrfs_header_generation(parent); path->slots[*level]++; + + mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_free_extent(trans, root, bytenr, blocksize, root_owner, root_gen, 0, 0, 1); BUG_ON(ret); + mutex_unlock(&root->fs_info->alloc_mutex); continue; } - + /* + * at this point, we have a single ref, and since the + * only place referencing this extent is a dead root + * the reference count should never go higher. + * So, we don't need to check it again + */ if (*level == 1) { struct btrfs_key key; btrfs_node_key_to_cpu(cur, &key, path->slots[*level]); @@ -2533,33 +2562,23 @@ static int noinline walk_down_tree(struct btrfs_trans_handle *trans, next = btrfs_find_tree_block(root, bytenr, blocksize); if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) { free_extent_buffer(next); - mutex_unlock(&root->fs_info->alloc_mutex); if (path->slots[*level] == 0) reada_walk_down(root, cur, path->slots[*level]); next = read_tree_block(root, bytenr, blocksize, ptr_gen); cond_resched(); - mutex_lock(&root->fs_info->alloc_mutex); - - /* we've dropped the lock, double check */ +#if 0 + /* + * this is a debugging check and can go away + * the ref should never go all the way down to 1 + * at this point + */ ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs); BUG_ON(ret); - if (refs != 1) { - parent = path->nodes[*level]; - root_owner = btrfs_header_owner(parent); - root_gen = btrfs_header_generation(parent); - - path->slots[*level]++; - free_extent_buffer(next); - ret = __btrfs_free_extent(trans, root, bytenr, - blocksize, - root_owner, - root_gen, 0, 0, 1); - BUG_ON(ret); - continue; - } + WARN_ON(refs != 1); +#endif } WARN_ON(*level <= 0); if (path->nodes[*level-1]) @@ -2584,6 +2603,8 @@ out: root_owner = btrfs_header_owner(parent); root_gen = btrfs_header_generation(parent); + + mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_free_extent(trans, root, bytenr, blocksize, root_owner, root_gen, 0, 0, 1); free_extent_buffer(path->nodes[*level]); @@ -2591,6 +2612,7 @@ out: *level += 1; BUG_ON(ret); mutex_unlock(&root->fs_info->alloc_mutex); + cond_resched(); return 0; } @@ -2834,6 +2856,11 @@ again: } set_page_extent_mapped(page); + /* + * make sure page_mkwrite is called for this page if userland + * wants to change it from mmap + */ + clear_page_dirty_for_io(page); set_extent_delalloc(io_tree, page_start, page_end, GFP_NOFS); |