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>

diff --git a/fs/namei.c b/fs/namei.c
index 22814d067fede71b65202ac1209e71c2070d7cd0..1a117c0d13c5cbeca8bd329aa4b1cb134dd75f0d 100644 (file)
--- 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;
 }