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-rw-r--r--fs/btrfs/ctree.c74
-rw-r--r--fs/btrfs/ctree.h1
-rw-r--r--fs/btrfs/disk-io.c1
-rw-r--r--fs/btrfs/extent-tree.c1
4 files changed, 38 insertions, 39 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index dff4da0..1b756fa 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -63,7 +63,6 @@ void btrfs_free_path(struct btrfs_path *p)
void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
{
int i;
- int skip = p->skip_locking;
int keep = p->keep_locks;
for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
@@ -76,7 +75,6 @@ void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
free_extent_buffer(p->nodes[i]);
}
memset(p, 0, sizeof(*p));
- p->skip_locking = skip;
p->keep_locks = keep;
}
@@ -1137,7 +1135,6 @@ static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
return;
node = path->nodes[level];
- WARN_ON(!path->skip_locking && !btrfs_tree_locked(node));
search = btrfs_node_blockptr(node, slot);
blocksize = btrfs_level_size(root, level - 1);
@@ -1192,6 +1189,7 @@ static void unlock_up(struct btrfs_path *path, int level, int lowest_unlock)
{
int i;
int skip_level = level;
+ int no_skips = 0;
struct extent_buffer *t;
for (i = level; i < BTRFS_MAX_LEVEL; i++) {
@@ -1199,27 +1197,24 @@ static void unlock_up(struct btrfs_path *path, int level, int lowest_unlock)
break;
if (!path->locks[i])
break;
- if (path->slots[i] == 0) {
+ if (!no_skips && path->slots[i] == 0) {
skip_level = i + 1;
continue;
}
- if (path->keep_locks) {
+ if (!no_skips && path->keep_locks) {
u32 nritems;
t = path->nodes[i];
nritems = btrfs_header_nritems(t);
- if (nritems < 2 || path->slots[i] >= nritems - 2) {
-if (path->keep_locks) {
-//printk("path %p skip level now %d\n", path, skip_level);
-}
+ if (nritems < 1 || path->slots[i] >= nritems - 1) {
skip_level = i + 1;
continue;
}
}
+ if (skip_level < i && i >= lowest_unlock)
+ no_skips = 1;
+
t = path->nodes[i];
if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
-if (path->keep_locks) {
-//printk("path %p unlocking level %d slot %d nritems %d skip_level %d\n", path, i, path->slots[i], btrfs_header_nritems(t), skip_level);
-}
btrfs_tree_unlock(t);
path->locks[i] = 0;
}
@@ -1244,6 +1239,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
ins_len, int cow)
{
struct extent_buffer *b;
+ struct extent_buffer *tmp;
int slot;
int ret;
int level;
@@ -1263,10 +1259,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
if (ins_len < 0)
lowest_unlock = 2;
again:
- if (!p->skip_locking)
- b = btrfs_lock_root_node(root);
- else
- b = btrfs_root_node(root);
+ b = btrfs_lock_root_node(root);
while (b) {
level = btrfs_header_level(b);
@@ -1286,8 +1279,7 @@ again:
WARN_ON(1);
level = btrfs_header_level(b);
p->nodes[level] = b;
- if (!p->skip_locking)
- p->locks[level] = 1;
+ p->locks[level] = 1;
ret = check_block(root, p, level);
if (ret)
return -1;
@@ -1328,10 +1320,29 @@ again:
reada_for_search(root, p, level, slot,
key->objectid);
- b = read_node_slot(root, b, slot);
- if (!p->skip_locking)
- btrfs_tree_lock(b);
- unlock_up(p, level + 1, lowest_unlock);
+ tmp = btrfs_find_tree_block(root,
+ btrfs_node_blockptr(b, slot),
+ btrfs_level_size(root, level - 1));
+ if (tmp && btrfs_buffer_uptodate(tmp,
+ btrfs_node_ptr_generation(b, slot))) {
+ b = tmp;
+ } else {
+ /*
+ * reduce lock contention at high levels
+ * of the btree by dropping locks before
+ * we read.
+ */
+ if (level > 1) {
+ btrfs_release_path(NULL, p);
+ if (tmp)
+ free_extent_buffer(tmp);
+ goto again;
+ } else {
+ b = read_node_slot(root, b, slot);
+ }
+ }
+ btrfs_tree_lock(b);
+ unlock_up(p, level, lowest_unlock);
} else {
p->slots[level] = slot;
if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
@@ -3007,17 +3018,8 @@ 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, c, slot);
- if (!path->skip_locking) {
- if (!btrfs_tree_locked(c)) {
- int i;
- WARN_ON(1);
-printk("path %p no lock on level %d\n", path, level);
-for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
-printk("path %p level %d slot %d nritems %d\n", path, i, path->slots[i], btrfs_header_nritems(path->nodes[i]));
-}
- }
- btrfs_tree_lock(next);
- }
+ WARN_ON(!btrfs_tree_locked(c));
+ btrfs_tree_lock(next);
break;
}
path->slots[level] = slot;
@@ -3035,10 +3037,8 @@ printk("path %p level %d slot %d nritems %d\n", path, i, path->slots[i], btrfs_h
if (level == 1 && path->locks[1] && path->reada)
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_tree_lock(next);
- }
+ WARN_ON(!btrfs_tree_locked(path->nodes[level]));
+ btrfs_tree_lock(next);
}
done:
unlock_up(path, 0, 1);
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 692b8ea..9ea12d4 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -336,7 +336,6 @@ struct btrfs_path {
/* keep some upper locks as we walk down */
int keep_locks;
int lowest_level;
- int skip_locking;
};
/*
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f638803..ffc363d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1684,6 +1684,7 @@ void btrfs_throttle(struct btrfs_root *root)
#else
blk_congestion_wait(WRITE, HZ/20);
#endif
+
}
}
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 890b9e9..0905653 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -88,7 +88,6 @@ static int cache_block_group(struct btrfs_root *root,
return -ENOMEM;
path->reada = 2;
- path->skip_locking = 1;
first_free = block_group->key.objectid;
key.objectid = block_group->key.objectid;
key.offset = 0;
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