Btrfs: make some tree searches in send.c more efficient
We have this pattern where we do search for a contiguous group of
items in a tree and everytime we find an item, we process it, then
we release our path, increment the offset of the search key, do
another full tree search and repeat these steps until a tree search
can't find more items we're interested in.
Instead of doing these full tree searches after processing each item,
just process the next item/slot in our leaf and don't release the path.
Since all these trees are read only and we always use the commit root
for a search and skip node/leaf locks, we're not affecting concurrency
on the trees.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 89fefbd..a2621e7 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -2501,17 +2501,26 @@
key.objectid = dir;
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = 0;
+ ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
while (1) {
- ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
- 1, 0);
- if (ret < 0)
- goto out;
- if (!ret) {
- eb = path->nodes[0];
- slot = path->slots[0];
- btrfs_item_key_to_cpu(eb, &found_key, slot);
+ eb = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(eb)) {
+ ret = btrfs_next_leaf(sctx->send_root, path);
+ if (ret < 0) {
+ goto out;
+ } else if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ continue;
}
- if (ret || found_key.objectid != key.objectid ||
+
+ btrfs_item_key_to_cpu(eb, &found_key, slot);
+ if (found_key.objectid != key.objectid ||
found_key.type != key.type) {
ret = 0;
goto out;
@@ -2526,8 +2535,7 @@
goto out;
}
- key.offset = found_key.offset + 1;
- btrfs_release_path(path);
+ path->slots[0]++;
}
out:
@@ -2693,19 +2701,24 @@
key.objectid = dir;
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = 0;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
while (1) {
- ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
- if (ret < 0)
- goto out;
- if (!ret) {
- btrfs_item_key_to_cpu(path->nodes[0], &found_key,
- path->slots[0]);
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ else if (ret > 0)
+ break;
+ continue;
}
- if (ret || found_key.objectid != key.objectid ||
- found_key.type != key.type) {
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ if (found_key.objectid != key.objectid ||
+ found_key.type != key.type)
break;
- }
di = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_item);
@@ -2716,8 +2729,7 @@
goto out;
}
- btrfs_release_path(path);
- key.offset = found_key.offset + 1;
+ path->slots[0]++;
}
ret = 1;
@@ -3620,15 +3632,22 @@
key.objectid = sctx->cmp_key->objectid;
key.type = BTRFS_INODE_REF_KEY;
key.offset = 0;
- while (1) {
- ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
- if (ret < 0)
- goto out;
- if (ret)
- break;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ while (1) {
eb = path->nodes[0];
slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(eb)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ else if (ret > 0)
+ break;
+ continue;
+ }
+
btrfs_item_key_to_cpu(eb, &found_key, slot);
if (found_key.objectid != key.objectid ||
@@ -3637,11 +3656,10 @@
break;
ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
- btrfs_release_path(path);
if (ret < 0)
goto out;
- key.offset = found_key.offset + 1;
+ path->slots[0]++;
}
btrfs_release_path(path);
@@ -3922,19 +3940,25 @@
key.objectid = sctx->cmp_key->objectid;
key.type = BTRFS_XATTR_ITEM_KEY;
key.offset = 0;
- while (1) {
- ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
- if (ret < 0)
- goto out;
- if (ret) {
- ret = 0;
- goto out;
- }
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ while (1) {
eb = path->nodes[0];
slot = path->slots[0];
- btrfs_item_key_to_cpu(eb, &found_key, slot);
+ if (slot >= btrfs_header_nritems(eb)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0) {
+ goto out;
+ } else if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ continue;
+ }
+ btrfs_item_key_to_cpu(eb, &found_key, slot);
if (found_key.objectid != key.objectid ||
found_key.type != key.type) {
ret = 0;
@@ -3946,8 +3970,7 @@
if (ret < 0)
goto out;
- btrfs_release_path(path);
- key.offset = found_key.offset + 1;
+ path->slots[0]++;
}
out: