Embed a struct path into struct nameidata instead of nd->{dentry,mnt}

This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.

Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
  <dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
  struct path in every place where the stack can be traversed
- it reduces the overall code size:

without patch series:
   text    data     bss     dec     hex filename
5321639  858418  715768 6895825  6938d1 vmlinux

with patch series:
   text    data     bss     dec     hex filename
5320026  858418  715768 6894212  693284 vmlinux

This patch:

Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 22 insertions, 20 deletions

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index 973c5c3705e3..f2bef5e14faa 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -259,7 +259,7 @@ osf_statfs(char __user *path, struct osf_statfs __user *buffer, unsigned long bu
 
         retval = user_path_walk(path, &nd);
         if (!retval) {
-                retval = do_osf_statfs(nd.dentry, buffer, bufsiz);
+                retval = do_osf_statfs(nd.path.dentry, buffer, bufsiz);
                 path_release(&nd);
         }
         return retval;
diff --git a/arch/mips/kernel/sysirix.c b/arch/mips/kernel/sysirix.c
index d70c4e0e85fb..49d6292ffa05 100644
--- a/arch/mips/kernel/sysirix.c
+++ b/arch/mips/kernel/sysirix.c
@@ -694,7 +694,7 @@ asmlinkage int irix_statfs(const char __user *path,
         if (error)
                 goto out;
 
-        error = vfs_statfs(nd.dentry, &kbuf);
+        error = vfs_statfs(nd.path.dentry, &kbuf);
         if (error)
                 goto dput_and_out;
 
@@ -1360,7 +1360,7 @@ asmlinkage int irix_statvfs(char __user *fname, struct irix_statvfs __user *buf)
         error = user_path_walk(fname, &nd);
         if (error)
                 goto out;
-        error = vfs_statfs(nd.dentry, &kbuf);
+        error = vfs_statfs(nd.path.dentry, &kbuf);
         if (error)
                 goto dput_and_out;
 
@@ -1611,7 +1611,7 @@ asmlinkage int irix_statvfs64(char __user *fname, struct irix_statvfs64 __user *
         error = user_path_walk(fname, &nd);
         if (error)
                 goto out;
-        error = vfs_statfs(nd.dentry, &kbuf);
+        error = vfs_statfs(nd.path.dentry, &kbuf);
         if (error)
                 goto dput_and_out;
 
diff --git a/arch/parisc/hpux/sys_hpux.c b/arch/parisc/hpux/sys_hpux.c
index 3e025df2dc86..d7395af3e846 100644
--- a/arch/parisc/hpux/sys_hpux.c
+++ b/arch/parisc/hpux/sys_hpux.c
@@ -219,7 +219,7 @@ asmlinkage long hpux_statfs(const char __user *path,
         error = user_path_walk(path, &nd);
         if (!error) {
                 struct hpux_statfs tmp;
-                error = vfs_statfs_hpux(nd.dentry, &tmp);
+                error = vfs_statfs_hpux(nd.path.dentry, &tmp);
                 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
                         error = -EFAULT;
                 path_release(&nd);
diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index e6e6559c55ed..6d1228c66c5e 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -1,3 +1,4 @@
+
 /*
  * SPU file system
  *
@@ -592,7 +593,7 @@ long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode,
 
         ret = -EINVAL;
         /* check if we are on spufs */
-        if (nd->dentry->d_sb->s_type != &spufs_type)
+        if (nd->path.dentry->d_sb->s_type != &spufs_type)
                 goto out;
 
         /* don't accept undefined flags */
@@ -600,9 +601,9 @@ long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode,
                 goto out;
 
         /* only threads can be underneath a gang */
-        if (nd->dentry != nd->dentry->d_sb->s_root) {
+        if (nd->path.dentry != nd->path.dentry->d_sb->s_root) {
                 if ((flags & SPU_CREATE_GANG) ||
-                    !SPUFS_I(nd->dentry->d_inode)->i_gang)
+                    !SPUFS_I(nd->path.dentry->d_inode)->i_gang)
                         goto out;
         }
 
@@ -618,16 +619,17 @@ long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode,
         mode &= ~current->fs->umask;
 
         if (flags & SPU_CREATE_GANG)
-                return spufs_create_gang(nd->dentry->d_inode,
-                                        dentry, nd->mnt, mode);
+                return spufs_create_gang(nd->path.dentry->d_inode,
+                                         dentry, nd->path.mnt, mode);
         else
-                return spufs_create_context(nd->dentry->d_inode,
-                                        dentry, nd->mnt, flags, mode, filp);
+                return spufs_create_context(nd->path.dentry->d_inode,
+                                            dentry, nd->path.mnt, flags, mode,
+                                            filp);
 
 out_dput:
         dput(dentry);
 out_dir:
-        mutex_unlock(&nd->dentry->d_inode->i_mutex);
+        mutex_unlock(&nd->path.dentry->d_inode->i_mutex);
 out:
         return ret;
 }
diff --git a/arch/sparc64/solaris/fs.c b/arch/sparc64/solaris/fs.c
index 9311bfe4f2f7..516932e9f70b 100644
--- a/arch/sparc64/solaris/fs.c
+++ b/arch/sparc64/solaris/fs.c
@@ -434,8 +434,8 @@ asmlinkage int solaris_statvfs(u32 path, u32 buf)
 
         error = user_path_walk(A(path),&nd);
         if (!error) {
-                struct inode * inode = nd.dentry->d_inode;
-                error = report_statvfs(nd.mnt, inode, buf);
+                struct inode *inode = nd.path.dentry->d_inode;
+                error = report_statvfs(nd.path.mnt, inode, buf);
                 path_release(&nd);
         }
         return error;
@@ -464,8 +464,8 @@ asmlinkage int solaris_statvfs64(u32 path, u32 buf)
         lock_kernel();
         error = user_path_walk(A(path), &nd);
         if (!error) {
-                struct inode * inode = nd.dentry->d_inode;
-                error = report_statvfs64(nd.mnt, inode, buf);
+                struct inode *inode = nd.path.dentry->d_inode;
+                error = report_statvfs64(nd.path.mnt, inode, buf);
                 path_release(&nd);
         }
         unlock_kernel();
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index ebb265c07e4d..19d579d74d27 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -145,8 +145,8 @@ void mconsole_proc(struct mc_request *req)
         }
         up_write(&super->s_umount);
 
-        nd.dentry = super->s_root;
-        nd.mnt = NULL;
+        nd.path.dentry = super->s_root;
+        nd.path.mnt = NULL;
         nd.flags = O_RDONLY + 1;
         nd.last_type = LAST_ROOT;
 
@@ -159,7 +159,7 @@ void mconsole_proc(struct mc_request *req)
                 goto out_kill;
         }
 
-        file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
+        file = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY);
         if (IS_ERR(file)) {
                 mconsole_reply(req, "Failed to open file", 1, 0);
                 goto out_kill;