vfs: make it possible to access the dentry hash/len as one 64-bit entry

This allows comparing hash and len in one operation on 64-bit
architectures.  Right now only __d_lookup_rcu() takes advantage of this,
since that is the case we care most about.

The use of anonymous struct/unions hides the alternate 64-bit approach
from most users, the exception being a few cases where we initialize a
'struct qstr' with a static initializer.  This makes the problematic
cases use a new QSTR_INIT() helper function for that (but initializing
just the name pointer with a "{ .name = xyzzy }" initializer remains
valid, as does just copying another qstr structure).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 4 deletions

diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index ac8e279eccc6..302f340d0071 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -146,10 +146,7 @@ static struct dentry *ufs_fh_to_parent(struct super_block *sb, struct fid *fid,
 
 static struct dentry *ufs_get_parent(struct dentry *child)
 {
-        struct qstr dot_dot = {
-                .name   = "..",
-                .len    = 2,
-        };
+        struct qstr dot_dot = QSTR_INIT("..", 2);
         ino_t ino;
 
         ino = ufs_inode_by_name(child->d_inode, &dot_dot);