summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJosef Bacik <josef@redhat.com>2011-05-27 12:06:11 -0400
committerJosef Bacik <josef@redhat.com>2011-07-11 09:58:45 -0400
commitfa09200b8334f9a6af3f656edae924a98d85630f (patch)
tree9213ac48212f70d86fb60834beb464d68be332ba
parent149e2d76b4886c4c7ff5e077646a8ba3563c8026 (diff)
Btrfs: try to only do one btrfs_search_slot in do_setxattr
I've been watching how many btrfs_search_slot()'s we do and I noticed that when we create a file with selinux enabled we were doing 2 each time we initialize the security context. That's because we lookup the xattr first so we can delete it if we're setting a new value to an existing xattr. But in the create case we don't have any xattrs, so it is completely useless to have the extra lookup. So re-arrange things so that we only lookup first if we specifically have XATTR_REPLACE. That way in the basic case we only do 1 search, and in the more complicated case we do the normal 2 lookups. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
-rw-r--r--fs/btrfs/dir-item.c9
-rw-r--r--fs/btrfs/xattr.c66
2 files changed, 42 insertions, 33 deletions
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 685f2593c4f0..c360a848d97f 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -89,13 +89,8 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
data_size = sizeof(*dir_item) + name_len + data_len;
dir_item = insert_with_overflow(trans, root, path, &key, data_size,
name, name_len);
- /*
- * FIXME: at some point we should handle xattr's that are larger than
- * what we can fit in our leaf. We set location to NULL b/c we arent
- * pointing at anything else, that will change if we store the xattr
- * data in a separate inode.
- */
- BUG_ON(IS_ERR(dir_item));
+ if (IS_ERR(dir_item))
+ return PTR_ERR(dir_item);
memset(&location, 0, sizeof(location));
leaf = path->nodes[0];
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 5366fe452ab0..d733b9cfea34 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -102,43 +102,57 @@ static int do_setxattr(struct btrfs_trans_handle *trans,
if (!path)
return -ENOMEM;
- /* first lets see if we already have this xattr */
- di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name,
- strlen(name), -1);
- if (IS_ERR(di)) {
- ret = PTR_ERR(di);
- goto out;
- }
-
- /* ok we already have this xattr, lets remove it */
- if (di) {
- /* if we want create only exit */
- if (flags & XATTR_CREATE) {
- ret = -EEXIST;
+ if (flags & XATTR_REPLACE) {
+ di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name,
+ name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ } else if (!di) {
+ ret = -ENODATA;
goto out;
}
-
ret = btrfs_delete_one_dir_name(trans, root, path, di);
- BUG_ON(ret);
+ if (ret)
+ goto out;
btrfs_release_path(path);
+ }
- /* if we don't have a value then we are removing the xattr */
- if (!value)
+again:
+ ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
+ name, name_len, value, size);
+ if (ret == -EEXIST) {
+ if (flags & XATTR_CREATE)
goto out;
- } else {
+ /*
+ * We can't use the path we already have since we won't have the
+ * proper locking for a delete, so release the path and
+ * re-lookup to delete the thing.
+ */
btrfs_release_path(path);
+ di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
+ name, name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ } else if (!di) {
+ /* Shouldn't happen but just in case... */
+ btrfs_release_path(path);
+ goto again;
+ }
- if (flags & XATTR_REPLACE) {
- /* we couldn't find the attr to replace */
- ret = -ENODATA;
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ if (ret)
goto out;
+
+ /*
+ * We have a value to set, so go back and try to insert it now.
+ */
+ if (value) {
+ btrfs_release_path(path);
+ goto again;
}
}
-
- /* ok we have to create a completely new xattr */
- ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
- name, name_len, value, size);
- BUG_ON(ret);
out:
btrfs_free_path(path);
return ret;