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-rw-r--r--fs/btrfs/disk-io.c46
1 files changed, 45 insertions, 1 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5aebddd7119..adda739a021 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -75,6 +75,40 @@ struct async_submit_bio {
75 struct btrfs_work work; 75 struct btrfs_work work;
76}; 76};
77 77
78/* These are used to set the lockdep class on the extent buffer locks.
79 * The class is set by the readpage_end_io_hook after the buffer has
80 * passed csum validation but before the pages are unlocked.
81 *
82 * The lockdep class is also set by btrfs_init_new_buffer on freshly
83 * allocated blocks.
84 *
85 * The class is based on the level in the tree block, which allows lockdep
86 * to know that lower nodes nest inside the locks of higher nodes.
87 *
88 * We also add a check to make sure the highest level of the tree is
89 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
90 * code needs update as well.
91 */
92#ifdef CONFIG_DEBUG_LOCK_ALLOC
93# if BTRFS_MAX_LEVEL != 8
94# error
95# endif
96static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
97static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
98 /* leaf */
99 "btrfs-extent-00",
100 "btrfs-extent-01",
101 "btrfs-extent-02",
102 "btrfs-extent-03",
103 "btrfs-extent-04",
104 "btrfs-extent-05",
105 "btrfs-extent-06",
106 "btrfs-extent-07",
107 /* highest possible level */
108 "btrfs-extent-08",
109};
110#endif
111
78/* 112/*
79 * extents on the btree inode are pretty simple, there's one extent 113 * extents on the btree inode are pretty simple, there's one extent
80 * that covers the entire device 114 * that covers the entire device
@@ -347,6 +381,15 @@ static int check_tree_block_fsid(struct btrfs_root *root,
347 return ret; 381 return ret;
348} 382}
349 383
384#ifdef CONFIG_DEBUG_LOCK_ALLOC
385void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
386{
387 lockdep_set_class_and_name(&eb->lock,
388 &btrfs_eb_class[level],
389 btrfs_eb_name[level]);
390}
391#endif
392
350static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, 393static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
351 struct extent_state *state) 394 struct extent_state *state)
352{ 395{
@@ -392,6 +435,8 @@ static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
392 } 435 }
393 found_level = btrfs_header_level(eb); 436 found_level = btrfs_header_level(eb);
394 437
438 btrfs_set_buffer_lockdep_class(eb, found_level);
439
395 ret = csum_tree_block(root, eb, 1); 440 ret = csum_tree_block(root, eb, 1);
396 if (ret) 441 if (ret)
397 ret = -EIO; 442 ret = -EIO;
@@ -1777,7 +1822,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
1777 ret = find_and_setup_root(tree_root, fs_info, 1822 ret = find_and_setup_root(tree_root, fs_info,
1778 BTRFS_DEV_TREE_OBJECTID, dev_root); 1823 BTRFS_DEV_TREE_OBJECTID, dev_root);
1779 dev_root->track_dirty = 1; 1824 dev_root->track_dirty = 1;
1780
1781 if (ret) 1825 if (ret)
1782 goto fail_extent_root; 1826 goto fail_extent_root;
1783 1827