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>

2 files changed, 4 insertions, 4 deletions

diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 16ad84d8402f..abd51331345e 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -2361,7 +2361,7 @@ int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
                          * by passing 'ubifs_tnc_remove_nm()' the same key but
                          * an unmatchable name.
                          */
-                        struct qstr noname = { .len = 0, .name = "" };
+                        struct qstr noname = { .name = "" };
 
                         err = dbg_check_tnc(c, 0);
                         mutex_unlock(&c->tnc_mutex);
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index 85b272268754..7a8bafa19c9f 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -298,7 +298,7 @@ int ubifs_setxattr(struct dentry *dentry, const char *name,
 {
         struct inode *inode, *host = dentry->d_inode;
         struct ubifs_info *c = host->i_sb->s_fs_info;
-        struct qstr nm = { .name = name, .len = strlen(name) };
+        struct qstr nm = QSTR_INIT(name, strlen(name));
         struct ubifs_dent_node *xent;
         union ubifs_key key;
         int err, type;
@@ -361,7 +361,7 @@ ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
 {
         struct inode *inode, *host = dentry->d_inode;
         struct ubifs_info *c = host->i_sb->s_fs_info;
-        struct qstr nm = { .name = name, .len = strlen(name) };
+        struct qstr nm = QSTR_INIT(name, strlen(name));
         struct ubifs_inode *ui;
         struct ubifs_dent_node *xent;
         union ubifs_key key;
@@ -524,7 +524,7 @@ int ubifs_removexattr(struct dentry *dentry, const char *name)
 {
         struct inode *inode, *host = dentry->d_inode;
         struct ubifs_info *c = host->i_sb->s_fs_info;
-        struct qstr nm = { .name = name, .len = strlen(name) };
+        struct qstr nm = QSTR_INIT(name, strlen(name));
         struct ubifs_dent_node *xent;
         union ubifs_key key;
         int err;