diff options
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 103 |
1 files changed, 70 insertions, 33 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 97f22ff8326f..94ecac33cf2d 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -100,38 +100,83 @@ struct async_submit_bio { struct btrfs_work work; }; -/* These are used to set the lockdep class on the extent buffer locks. - * The class is set by the readpage_end_io_hook after the buffer has - * passed csum validation but before the pages are unlocked. +/* + * Lockdep class keys for extent_buffer->lock's in this root. For a given + * eb, the lockdep key is determined by the btrfs_root it belongs to and + * the level the eb occupies in the tree. + * + * Different roots are used for different purposes and may nest inside each + * other and they require separate keysets. As lockdep keys should be + * static, assign keysets according to the purpose of the root as indicated + * by btrfs_root->objectid. This ensures that all special purpose roots + * have separate keysets. * - * The lockdep class is also set by btrfs_init_new_buffer on freshly - * allocated blocks. + * Lock-nesting across peer nodes is always done with the immediate parent + * node locked thus preventing deadlock. As lockdep doesn't know this, use + * subclass to avoid triggering lockdep warning in such cases. * - * The class is based on the level in the tree block, which allows lockdep - * to know that lower nodes nest inside the locks of higher nodes. + * The key is set by the readpage_end_io_hook after the buffer has passed + * csum validation but before the pages are unlocked. It is also set by + * btrfs_init_new_buffer on freshly allocated blocks. * - * We also add a check to make sure the highest level of the tree is - * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this - * code needs update as well. + * We also add a check to make sure the highest level of the tree is the + * same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this code + * needs update as well. */ #ifdef CONFIG_DEBUG_LOCK_ALLOC # if BTRFS_MAX_LEVEL != 8 # error # endif -static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1]; -static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = { - /* leaf */ - "btrfs-extent-00", - "btrfs-extent-01", - "btrfs-extent-02", - "btrfs-extent-03", - "btrfs-extent-04", - "btrfs-extent-05", - "btrfs-extent-06", - "btrfs-extent-07", - /* highest possible level */ - "btrfs-extent-08", + +static struct btrfs_lockdep_keyset { + u64 id; /* root objectid */ + const char *name_stem; /* lock name stem */ + char names[BTRFS_MAX_LEVEL + 1][20]; + struct lock_class_key keys[BTRFS_MAX_LEVEL + 1]; +} btrfs_lockdep_keysets[] = { + { .id = BTRFS_ROOT_TREE_OBJECTID, .name_stem = "root" }, + { .id = BTRFS_EXTENT_TREE_OBJECTID, .name_stem = "extent" }, + { .id = BTRFS_CHUNK_TREE_OBJECTID, .name_stem = "chunk" }, + { .id = BTRFS_DEV_TREE_OBJECTID, .name_stem = "dev" }, + { .id = BTRFS_FS_TREE_OBJECTID, .name_stem = "fs" }, + { .id = BTRFS_CSUM_TREE_OBJECTID, .name_stem = "csum" }, + { .id = BTRFS_ORPHAN_OBJECTID, .name_stem = "orphan" }, + { .id = BTRFS_TREE_LOG_OBJECTID, .name_stem = "log" }, + { .id = BTRFS_TREE_RELOC_OBJECTID, .name_stem = "treloc" }, + { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc" }, + { .id = 0, .name_stem = "tree" }, }; + +void __init btrfs_init_lockdep(void) +{ + int i, j; + + /* initialize lockdep class names */ + for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) { + struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i]; + + for (j = 0; j < ARRAY_SIZE(ks->names); j++) + snprintf(ks->names[j], sizeof(ks->names[j]), + "btrfs-%s-%02d", ks->name_stem, j); + } +} + +void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb, + int level) +{ + struct btrfs_lockdep_keyset *ks; + + BUG_ON(level >= ARRAY_SIZE(ks->keys)); + + /* find the matching keyset, id 0 is the default entry */ + for (ks = btrfs_lockdep_keysets; ks->id; ks++) + if (ks->id == objectid) + break; + + lockdep_set_class_and_name(&eb->lock, + &ks->keys[level], ks->names[level]); +} + #endif /* @@ -491,15 +536,6 @@ static noinline int check_leaf(struct btrfs_root *root, return 0; } -#ifdef CONFIG_DEBUG_LOCK_ALLOC -void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level) -{ - lockdep_set_class_and_name(&eb->lock, - &btrfs_eb_class[level], - btrfs_eb_name[level]); -} -#endif - static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, struct extent_state *state) { @@ -550,7 +586,8 @@ static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, } found_level = btrfs_header_level(eb); - btrfs_set_buffer_lockdep_class(eb, found_level); + btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb), + eb, found_level); ret = csum_tree_block(root, eb, 1); if (ret) { |