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>

4 files changed, 4 insertions, 10 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 8789210c6905..eedd24d0ad2e 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -477,10 +477,7 @@ different:
 static
 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
 {
-        struct qstr filename = {
-                .len = entry->len,
-                .name = entry->name,
-        };
+        struct qstr filename = QSTR_INIT(entry->name, entry->len);
         struct dentry *dentry;
         struct dentry *alias;
         struct inode *dir = parent->d_inode;
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 5242eae6711a..75c68299358e 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -398,8 +398,7 @@ nfs3_proc_remove(struct inode *dir, struct qstr *name)
 {
         struct nfs_removeargs arg = {
                 .fh = NFS_FH(dir),
-                .name.len = name->len,
-                .name.name = name->name,
+                .name = *name,
         };
         struct nfs_removeres res;
         struct rpc_message msg = {
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 99650aaf8937..ab985f6f0da8 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2782,8 +2782,7 @@ static int _nfs4_proc_remove(struct inode *dir, struct qstr *name)
         struct nfs_server *server = NFS_SERVER(dir);
         struct nfs_removeargs args = {
                 .fh = NFS_FH(dir),
-                .name.len = name->len,
-                .name.name = name->name,
+                .name = *name,
                 .bitmask = server->attr_bitmask,
         };
         struct nfs_removeres res = {
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index b63b6f4d14fb..d6408b6437de 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -335,8 +335,7 @@ nfs_proc_remove(struct inode *dir, struct qstr *name)
 {
         struct nfs_removeargs arg = {
                 .fh = NFS_FH(dir),
-                .name.len = name->len,
-                .name.name = name->name,
+                .name = *name,
         };
         struct rpc_message msg = { 
                 .rpc_proc = &nfs_procedures[NFSPROC_REMOVE],