Btrfs: Lower contention on the csum mutex
This takes the csum mutex deeper in the call chain and releases it
more often.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 51aba8c..9454e0a 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -321,6 +321,7 @@
file_key.offset = offset;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+ mutex_lock(&BTRFS_I(inode)->csum_mutex);
item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
if (!IS_ERR(item)) {
leaf = path->nodes[0];
@@ -367,7 +368,7 @@
ret = btrfs_search_slot(trans, root, &file_key, path,
BTRFS_CRC32_SIZE, 1);
if (ret < 0)
- goto fail;
+ goto fail_unlock;
if (ret == 0) {
BUG();
}
@@ -411,10 +412,10 @@
ret = btrfs_insert_empty_item(trans, root, path, &file_key,
ins_size);
if (ret < 0)
- goto fail;
+ goto fail_unlock;
if (ret != 0) {
WARN_ON(1);
- goto fail;
+ goto fail_unlock;
}
csum:
leaf = path->nodes[0];
@@ -427,6 +428,8 @@
item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
btrfs_item_size_nr(leaf, path->slots[0]));
eb_token = NULL;
+ mutex_unlock(&BTRFS_I(inode)->csum_mutex);
+ cond_resched();
next_sector:
if (!eb_token ||
@@ -467,13 +470,18 @@
eb_token = NULL;
}
btrfs_mark_buffer_dirty(path->nodes[0]);
+ cond_resched();
if (total_bytes < sums->len) {
btrfs_release_path(root, path);
goto again;
}
-fail:
+out:
btrfs_free_path(path);
return ret;
+
+fail_unlock:
+ mutex_unlock(&BTRFS_I(inode)->csum_mutex);
+ goto out;
}
int btrfs_csum_truncate(struct btrfs_trans_handle *trans,