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-rw-r--r--fs/btrfs/ctree.c71
1 files changed, 43 insertions, 28 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 551177c..37f31b5 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -38,19 +38,12 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int level, int slot);
-inline void btrfs_init_path(struct btrfs_path *p)
-{
- memset(p, 0, sizeof(*p));
-}
-
struct btrfs_path *btrfs_alloc_path(void)
{
struct btrfs_path *path;
- path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
- if (path) {
- btrfs_init_path(path);
+ path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
+ if (path)
path->reada = 1;
- }
return path;
}
@@ -69,14 +62,38 @@ noinline void btrfs_set_path_blocking(struct btrfs_path *p)
/*
* reset all the locked nodes in the patch to spinning locks.
+ *
+ * held is used to keep lockdep happy, when lockdep is enabled
+ * we set held to a blocking lock before we go around and
+ * retake all the spinlocks in the path. You can safely use NULL
+ * for held
*/
-noinline void btrfs_clear_path_blocking(struct btrfs_path *p)
+noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
+ struct extent_buffer *held)
{
int i;
- for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /* lockdep really cares that we take all of these spinlocks
+ * in the right order. If any of the locks in the path are not
+ * currently blocking, it is going to complain. So, make really
+ * really sure by forcing the path to blocking before we clear
+ * the path blocking.
+ */
+ if (held)
+ btrfs_set_lock_blocking(held);
+ btrfs_set_path_blocking(p);
+#endif
+
+ for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
if (p->nodes[i] && p->locks[i])
btrfs_clear_lock_blocking(p->nodes[i]);
}
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ if (held)
+ btrfs_clear_lock_blocking(held);
+#endif
}
/* this also releases the path */
@@ -260,7 +277,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
if (*cow_ret == buf)
unlock_orig = 1;
- WARN_ON(!btrfs_tree_locked(buf));
+ btrfs_assert_tree_locked(buf);
if (parent)
parent_start = parent->start;
@@ -286,7 +303,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
trans->transid, level, &ins);
BUG_ON(ret);
cow = btrfs_init_new_buffer(trans, root, prealloc_dest,
- buf->len);
+ buf->len, level);
} else {
cow = btrfs_alloc_free_block(trans, root, buf->len,
parent_start,
@@ -917,9 +934,9 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
/* promote the child to a root */
child = read_node_slot(root, mid, 0);
+ BUG_ON(!child);
btrfs_tree_lock(child);
btrfs_set_lock_blocking(child);
- BUG_ON(!child);
ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0);
BUG_ON(ret);
@@ -1530,8 +1547,7 @@ again:
* for higher level blocks, try not to allocate blocks
* with the block and the parent locks held.
*/
- if (level > 0 && !prealloc_block.objectid &&
- btrfs_path_lock_waiting(p, level)) {
+ if (level > 0 && !prealloc_block.objectid) {
u32 size = b->len;
u64 hint = b->start;
@@ -1567,7 +1583,7 @@ cow_done:
if (!p->skip_locking)
p->locks[level] = 1;
- btrfs_clear_path_blocking(p);
+ btrfs_clear_path_blocking(p, NULL);
/*
* we have a lock on b and as long as we aren't changing
@@ -1606,7 +1622,7 @@ cow_done:
btrfs_set_path_blocking(p);
sret = split_node(trans, root, p, level);
- btrfs_clear_path_blocking(p);
+ btrfs_clear_path_blocking(p, NULL);
BUG_ON(sret > 0);
if (sret) {
@@ -1626,7 +1642,7 @@ cow_done:
btrfs_set_path_blocking(p);
sret = balance_level(trans, root, p, level);
- btrfs_clear_path_blocking(p);
+ btrfs_clear_path_blocking(p, NULL);
if (sret) {
ret = sret;
@@ -1689,13 +1705,13 @@ cow_done:
if (!p->skip_locking) {
int lret;
- btrfs_clear_path_blocking(p);
+ btrfs_clear_path_blocking(p, NULL);
lret = btrfs_try_spin_lock(b);
if (!lret) {
btrfs_set_path_blocking(p);
btrfs_tree_lock(b);
- btrfs_clear_path_blocking(p);
+ btrfs_clear_path_blocking(p, b);
}
}
} else {
@@ -1707,7 +1723,7 @@ cow_done:
btrfs_set_path_blocking(p);
sret = split_leaf(trans, root, key,
p, ins_len, ret == 0);
- btrfs_clear_path_blocking(p);
+ btrfs_clear_path_blocking(p, NULL);
BUG_ON(sret > 0);
if (sret) {
@@ -2349,7 +2365,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
if (slot >= btrfs_header_nritems(upper) - 1)
return 1;
- WARN_ON(!btrfs_tree_locked(path->nodes[1]));
+ btrfs_assert_tree_locked(path->nodes[1]);
right = read_node_slot(root, upper, slot + 1);
btrfs_tree_lock(right);
@@ -2546,7 +2562,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
if (right_nritems == 0)
return 1;
- WARN_ON(!btrfs_tree_locked(path->nodes[1]));
+ btrfs_assert_tree_locked(path->nodes[1]);
left = read_node_slot(root, path->nodes[1], slot - 1);
btrfs_tree_lock(left);
@@ -3927,7 +3943,6 @@ find_next_key:
btrfs_release_path(root, path);
goto again;
} else {
- btrfs_clear_path_blocking(path);
goto out;
}
}
@@ -3947,7 +3962,7 @@ find_next_key:
path->locks[level - 1] = 1;
path->nodes[level - 1] = cur;
unlock_up(path, level, 1);
- btrfs_clear_path_blocking(path);
+ btrfs_clear_path_blocking(path, NULL);
}
out:
if (ret == 0)
@@ -4086,7 +4101,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
next = read_node_slot(root, c, slot);
if (!path->skip_locking) {
- WARN_ON(!btrfs_tree_locked(c));
+ btrfs_assert_tree_locked(c);
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
}
@@ -4111,7 +4126,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
reada_for_search(root, path, level, slot, 0);
next = read_node_slot(root, next, 0);
if (!path->skip_locking) {
- WARN_ON(!btrfs_tree_locked(path->nodes[level]));
+ btrfs_assert_tree_locked(path->nodes[level]);
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
}
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