hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Btrfs: make a lockdep class for each root 

This patch was originally from Tejun Heo.  lockdep complains about the btrfs
locking because we sometimes take btree locks from two different trees at the
same time.  The current classes are based only on level in the btree, which
isn't enough information for lockdep to figure out if the lock is safe.

This patch makes a class for each type of tree, and lumps all the FS trees that
actually have files and directories into the same class.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2011-07-26 16:11:19 -04:00
parent bd681513fa
commit 85d4e46111
4 changed files with 79 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

103
fs/btrfs/disk-io.c
View File

@ -100,38 +100,83 @@ struct async_submit_bio {
struct btrfs_work work; 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 * Lockdep class keys for extent_buffer->lock's in this root. For a given
* passed csum validation but before the pages are unlocked. * eb, the lockdep key is determined by the btrfs_root it belongs to and
* the level the eb occupies in the tree.
* *
* The lockdep class is also set by btrfs_init_new_buffer on freshly * Different roots are used for different purposes and may nest inside each
* allocated blocks. * 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 class is based on the level in the tree block, which allows lockdep * Lock-nesting across peer nodes is always done with the immediate parent
* to know that lower nodes nest inside the locks of higher nodes. * node locked thus preventing deadlock. As lockdep doesn't know this, use
* subclass to avoid triggering lockdep warning in such cases.
* *
* We also add a check to make sure the highest level of the tree is * The key is set by the readpage_end_io_hook after the buffer has passed
* the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this * csum validation but before the pages are unlocked. It is also set by
* code needs update as well. * 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.
*/ */
#ifdef CONFIG_DEBUG_LOCK_ALLOC #ifdef CONFIG_DEBUG_LOCK_ALLOC
# if BTRFS_MAX_LEVEL != 8 # if BTRFS_MAX_LEVEL != 8
# error # error
# endif # endif
static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = { static struct btrfs_lockdep_keyset {
/* leaf */ u64 id; /* root objectid */
"btrfs-extent-00", const char *name_stem; /* lock name stem */
"btrfs-extent-01", char names[BTRFS_MAX_LEVEL + 1][20];
"btrfs-extent-02", struct lock_class_key keys[BTRFS_MAX_LEVEL + 1];
"btrfs-extent-03", } btrfs_lockdep_keysets[] = {
"btrfs-extent-04", { .id = BTRFS_ROOT_TREE_OBJECTID, .name_stem = "root" },
"btrfs-extent-05", { .id = BTRFS_EXTENT_TREE_OBJECTID, .name_stem = "extent" },
"btrfs-extent-06", { .id = BTRFS_CHUNK_TREE_OBJECTID, .name_stem = "chunk" },
"btrfs-extent-07", { .id = BTRFS_DEV_TREE_OBJECTID, .name_stem = "dev" },
/* highest possible level */ { .id = BTRFS_FS_TREE_OBJECTID, .name_stem = "fs" },
"btrfs-extent-08", { .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 #endif
/* /*
@ -491,15 +536,6 @@ static noinline int check_leaf(struct btrfs_root *root,
return 0; 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, static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
struct extent_state *state) 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); 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); ret = csum_tree_block(root, eb, 1);
if (ret) { if (ret) {

10
fs/btrfs/disk-io.h
View File

@ -87,10 +87,14 @@ int btree_lock_page_hook(struct page *page);
#ifdef CONFIG_DEBUG_LOCK_ALLOC #ifdef CONFIG_DEBUG_LOCK_ALLOC
void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level); void btrfs_init_lockdep(void);
void btrfs_set_buffer_lockdep_class(u64 objectid,
struct extent_buffer *eb, int level);
#else #else
static inline void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, static inline void btrfs_init_lockdep(void)
int level) { }
static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
struct extent_buffer *eb, int level)
{ {
} }
#endif #endif

2
fs/btrfs/extent-tree.c
View File

@ -5625,7 +5625,7 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
if (!buf) if (!buf)
return ERR_PTR(-ENOMEM); return ERR_PTR(-ENOMEM);
btrfs_set_header_generation(buf, trans->transid); btrfs_set_header_generation(buf, trans->transid);
btrfs_set_buffer_lockdep_class(buf, level); btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
btrfs_tree_lock(buf); btrfs_tree_lock(buf);
clean_tree_block(trans, root, buf); clean_tree_block(trans, root, buf);

2
fs/btrfs/volumes.c
View File

@ -3595,7 +3595,7 @@ int btrfs_read_sys_array(struct btrfs_root *root)
if (!sb) if (!sb)
return -ENOMEM; return -ENOMEM;
btrfs_set_buffer_uptodate(sb); btrfs_set_buffer_uptodate(sb);
btrfs_set_buffer_lockdep_class(sb, 0); btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE); write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
array_size = btrfs_super_sys_array_size(super_copy); array_size = btrfs_super_sys_array_size(super_copy);