namei: move saved_nd pointer into struct nameidata

these guys are always declared next to each other; might as well put
the former (pointer to previous instance) into the latter and simplify
the calling conventions for {set,restore}_nameidata()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 24 insertions, 22 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 22814d067fed..1a117c0d13c5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -498,10 +498,8 @@ struct nameidata {
         struct qstr     last;
         struct path     root;
         struct inode    *inode; /* path.dentry.d_inode */
-        struct filename *name;
-        int             dfd;
         unsigned int    flags;
-        unsigned        seq, m_seq, root_seq;
+        unsigned        seq, m_seq;
         int             last_type;
         unsigned        depth;
         int             total_link_count;
@@ -512,23 +510,26 @@ struct nameidata {
                 struct inode *inode;
                 unsigned seq;
         } *stack, internal[EMBEDDED_LEVELS];
+        struct filename *name;
+        struct nameidata *saved;
+        unsigned        root_seq;
+        int             dfd;
 };
 
-static struct nameidata *set_nameidata(struct nameidata *p, int dfd,
-                                        struct filename *name)
+static void set_nameidata(struct nameidata *p, int dfd, struct filename *name)
 {
         struct nameidata *old = current->nameidata;
         p->stack = p->internal;
         p->dfd = dfd;
         p->name = name;
         p->total_link_count = old ? old->total_link_count : 0;
+        p->saved = old;
         current->nameidata = p;
-        return old;
 }
 
-static void restore_nameidata(struct nameidata *old)
+static void restore_nameidata(void)
 {
-        struct nameidata *now = current->nameidata;
+        struct nameidata *now = current->nameidata, *old = now->saved;
 
         current->nameidata = old;
         if (old)
@@ -2120,14 +2121,14 @@ static int filename_lookup(int dfd, struct filename *name, unsigned flags,
                            struct path *path, struct path *root)
 {
         int retval;
-        struct nameidata nd, *saved_nd;
+        struct nameidata nd;
         if (IS_ERR(name))
                 return PTR_ERR(name);
-        saved_nd = set_nameidata(&nd, dfd, name);
         if (unlikely(root)) {
                 nd.root = *root;
                 flags |= LOOKUP_ROOT;
         }
+        set_nameidata(&nd, dfd, name);
         retval = path_lookupat(&nd, flags | LOOKUP_RCU, path);
         if (unlikely(retval == -ECHILD))
                 retval = path_lookupat(&nd, flags, path);
@@ -2136,7 +2137,7 @@ static int filename_lookup(int dfd, struct filename *name, unsigned flags,
 
         if (likely(!retval))
                 audit_inode(name, path->dentry, flags & LOOKUP_PARENT);
-        restore_nameidata(saved_nd);
+        restore_nameidata();
         putname(name);
         return retval;
 }
@@ -2166,11 +2167,11 @@ static struct filename *filename_parentat(int dfd, struct filename *name,
                                 struct qstr *last, int *type)
 {
         int retval;
-        struct nameidata nd, *saved_nd;
+        struct nameidata nd;
 
         if (IS_ERR(name))
                 return name;
-        saved_nd = set_nameidata(&nd, dfd, name);
+        set_nameidata(&nd, dfd, name);
         retval = path_parentat(&nd, flags | LOOKUP_RCU, parent);
         if (unlikely(retval == -ECHILD))
                 retval = path_parentat(&nd, flags, parent);
@@ -2184,7 +2185,7 @@ static struct filename *filename_parentat(int dfd, struct filename *name,
                 putname(name);
                 name = ERR_PTR(retval);
         }
-        restore_nameidata(saved_nd);
+        restore_nameidata();
         return name;
 }
 
@@ -2445,11 +2446,11 @@ static int
 filename_mountpoint(int dfd, struct filename *name, struct path *path,
                         unsigned int flags)
 {
-        struct nameidata nd, *saved;
+        struct nameidata nd;
         int error;
         if (IS_ERR(name))
                 return PTR_ERR(name);
-        saved = set_nameidata(&nd, dfd, name);
+        set_nameidata(&nd, dfd, name);
         error = path_mountpoint(&nd, flags | LOOKUP_RCU, path);
         if (unlikely(error == -ECHILD))
                 error = path_mountpoint(&nd, flags, path);
@@ -2457,7 +2458,7 @@ filename_mountpoint(int dfd, struct filename *name, struct path *path,
                 error = path_mountpoint(&nd, flags | LOOKUP_REVAL, path);
         if (likely(!error))
                 audit_inode(name, path->dentry, 0);
-        restore_nameidata(saved);
+        restore_nameidata();
         putname(name);
         return error;
 }
@@ -3327,23 +3328,24 @@ out2:
 struct file *do_filp_open(int dfd, struct filename *pathname,
                 const struct open_flags *op)
 {
-        struct nameidata nd, *saved_nd = set_nameidata(&nd, dfd, pathname);
+        struct nameidata nd;
         int flags = op->lookup_flags;
         struct file *filp;
 
+        set_nameidata(&nd, dfd, pathname);
         filp = path_openat(&nd, op, flags | LOOKUP_RCU);
         if (unlikely(filp == ERR_PTR(-ECHILD)))
                 filp = path_openat(&nd, op, flags);
         if (unlikely(filp == ERR_PTR(-ESTALE)))
                 filp = path_openat(&nd, op, flags | LOOKUP_REVAL);
-        restore_nameidata(saved_nd);
+        restore_nameidata();
         return filp;
 }
 
 struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
                 const char *name, const struct open_flags *op)
 {
-        struct nameidata nd, *saved_nd;
+        struct nameidata nd;
         struct file *file;
         struct filename *filename;
         int flags = op->lookup_flags | LOOKUP_ROOT;
@@ -3358,13 +3360,13 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
         if (unlikely(IS_ERR(filename)))
                 return ERR_CAST(filename);
 
-        saved_nd = set_nameidata(&nd, -1, filename);
+        set_nameidata(&nd, -1, filename);
         file = path_openat(&nd, op, flags | LOOKUP_RCU);
         if (unlikely(file == ERR_PTR(-ECHILD)))
                 file = path_openat(&nd, op, flags);
         if (unlikely(file == ERR_PTR(-ESTALE)))
                 file = path_openat(&nd, op, flags | LOOKUP_REVAL);
-        restore_nameidata(saved_nd);
+        restore_nameidata();
         putname(filename);
         return file;
 }