Use struct path in fs_struct

* Use struct path in fs_struct.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 67 insertions, 85 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 44f6cf2..66aaf52 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1849,8 +1849,7 @@ char * d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
 				char *buf, int buflen)
 {
 	char *res;
-	struct vfsmount *rootmnt;
-	struct dentry *root;
+	struct path root;
 
 	/*
 	 * We have various synthetic filesystems that never get mounted.  On
@@ -1863,14 +1862,13 @@ char * d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
 		return dentry->d_op->d_dname(dentry, buf, buflen);
 
 	read_lock(&current->fs->lock);
-	rootmnt = mntget(current->fs->rootmnt);
-	root = dget(current->fs->root);
+	root = current->fs->root;
+	path_get(&current->fs->root);
 	read_unlock(&current->fs->lock);
 	spin_lock(&dcache_lock);
-	res = __d_path(dentry, vfsmnt, root, rootmnt, buf, buflen);
+	res = __d_path(dentry, vfsmnt, root.dentry, root.mnt, buf, buflen);
 	spin_unlock(&dcache_lock);
-	dput(root);
-	mntput(rootmnt);
+	path_put(&root);
 	return res;
 }
 
@@ -1916,28 +1914,28 @@ char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen,
 asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
 {
 	int error;
-	struct vfsmount *pwdmnt, *rootmnt;
-	struct dentry *pwd, *root;
+	struct path pwd, root;
 	char *page = (char *) __get_free_page(GFP_USER);
 
 	if (!page)
 		return -ENOMEM;
 
 	read_lock(&current->fs->lock);
-	pwdmnt = mntget(current->fs->pwdmnt);
-	pwd = dget(current->fs->pwd);
-	rootmnt = mntget(current->fs->rootmnt);
-	root = dget(current->fs->root);
+	pwd = current->fs->pwd;
+	path_get(&current->fs->pwd);
+	root = current->fs->root;
+	path_get(&current->fs->root);
 	read_unlock(&current->fs->lock);
 
 	error = -ENOENT;
 	/* Has the current directory has been unlinked? */
 	spin_lock(&dcache_lock);
-	if (pwd->d_parent == pwd || !d_unhashed(pwd)) {
+	if (pwd.dentry->d_parent == pwd.dentry || !d_unhashed(pwd.dentry)) {
 		unsigned long len;
 		char * cwd;
 
-		cwd = __d_path(pwd, pwdmnt, root, rootmnt, page, PAGE_SIZE);
+		cwd = __d_path(pwd.dentry, pwd.mnt, root.dentry, root.mnt,
+			       page, PAGE_SIZE);
 		spin_unlock(&dcache_lock);
 
 		error = PTR_ERR(cwd);
@@ -1955,10 +1953,8 @@ asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
 		spin_unlock(&dcache_lock);
 
 out:
-	dput(pwd);
-	mntput(pwdmnt);
-	dput(root);
-	mntput(rootmnt);
+	path_put(&pwd);
+	path_put(&root);
 	free_page((unsigned long) page);
 	return error;
 }
diff --git a/fs/namei.c b/fs/namei.c
index a6575ca..941c8e8 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -549,16 +549,16 @@ walk_init_root(const char *name, struct nameidata *nd)
 	struct fs_struct *fs = current->fs;
 
 	read_lock(&fs->lock);
-	if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
-		nd->path.mnt = mntget(fs->altrootmnt);
-		nd->path.dentry = dget(fs->altroot);
+	if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) {
+		nd->path = fs->altroot;
+		path_get(&fs->altroot);
 		read_unlock(&fs->lock);
 		if (__emul_lookup_dentry(name,nd))
 			return 0;
 		read_lock(&fs->lock);
 	}
-	nd->path.mnt = mntget(fs->rootmnt);
-	nd->path.dentry = dget(fs->root);
+	nd->path = fs->root;
+	path_get(&fs->root);
 	read_unlock(&fs->lock);
 	return 1;
 }
@@ -755,8 +755,8 @@ static __always_inline void follow_dotdot(struct nameidata *nd)
 		struct dentry *old = nd->path.dentry;
 
                 read_lock(&fs->lock);
-		if (nd->path.dentry == fs->root &&
-		    nd->path.mnt == fs->rootmnt) {
+		if (nd->path.dentry == fs->root.dentry &&
+		    nd->path.mnt == fs->root.mnt) {
                         read_unlock(&fs->lock);
 			break;
 		}
@@ -1078,8 +1078,8 @@ static int __emul_lookup_dentry(const char *name, struct nameidata *nd)
 		 */
 		nd->last_type = LAST_ROOT;
 		read_lock(&fs->lock);
-		nd->path.mnt = mntget(fs->rootmnt);
-		nd->path.dentry = dget(fs->root);
+		nd->path = fs->root;
+		path_get(&fs->root);
 		read_unlock(&fs->lock);
 		if (path_walk(name, nd) == 0) {
 			if (nd->path.dentry->d_inode) {
@@ -1099,29 +1099,22 @@ void set_fs_altroot(void)
 {
 	char *emul = __emul_prefix();
 	struct nameidata nd;
-	struct vfsmount *mnt = NULL, *oldmnt;
-	struct dentry *dentry = NULL, *olddentry;
+	struct path path = {}, old_path;
 	int err;
 	struct fs_struct *fs = current->fs;
 
 	if (!emul)
 		goto set_it;
 	err = path_lookup(emul, LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_NOALT, &nd);
-	if (!err) {
-		mnt = nd.path.mnt;
-		dentry = nd.path.dentry;
-	}
+	if (!err)
+		path = nd.path;
 set_it:
 	write_lock(&fs->lock);
-	oldmnt = fs->altrootmnt;
-	olddentry = fs->altroot;
-	fs->altrootmnt = mnt;
-	fs->altroot = dentry;
+	old_path = fs->altroot;
+	fs->altroot = path;
 	write_unlock(&fs->lock);
-	if (olddentry) {
-		dput(olddentry);
-		mntput(oldmnt);
-	}
+	if (old_path.dentry)
+		path_put(&old_path);
 }
 
 /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
@@ -1139,21 +1132,21 @@ static int do_path_lookup(int dfd, const char *name,
 
 	if (*name=='/') {
 		read_lock(&fs->lock);
-		if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
-			nd->path.mnt = mntget(fs->altrootmnt);
-			nd->path.dentry = dget(fs->altroot);
+		if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) {
+			nd->path = fs->altroot;
+			path_get(&fs->altroot);
 			read_unlock(&fs->lock);
 			if (__emul_lookup_dentry(name,nd))
 				goto out; /* found in altroot */
 			read_lock(&fs->lock);
 		}
-		nd->path.mnt = mntget(fs->rootmnt);
-		nd->path.dentry = dget(fs->root);
+		nd->path = fs->root;
+		path_get(&fs->root);
 		read_unlock(&fs->lock);
 	} else if (dfd == AT_FDCWD) {
 		read_lock(&fs->lock);
-		nd->path.mnt = mntget(fs->pwdmnt);
-		nd->path.dentry = dget(fs->pwd);
+		nd->path = fs->pwd;
+		path_get(&fs->pwd);
 		read_unlock(&fs->lock);
 	} else {
 		struct dentry *dentry;
diff --git a/fs/namespace.c b/fs/namespace.c
index c77eedd..ac19212 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -593,7 +593,7 @@ static int do_umount(struct vfsmount *mnt, int flags)
 	 *  (2) the usage count == 1 [parent vfsmount] + 1 [sys_umount]
 	 */
 	if (flags & MNT_EXPIRE) {
-		if (mnt == current->fs->rootmnt ||
+		if (mnt == current->fs->root.mnt ||
 		    flags & (MNT_FORCE | MNT_DETACH))
 			return -EINVAL;
 
@@ -628,7 +628,7 @@ static int do_umount(struct vfsmount *mnt, int flags)
 	 * /reboot - static binary that would close all descriptors and
 	 * call reboot(9). Then init(8) could umount root and exec /reboot.
 	 */
-	if (mnt == current->fs->rootmnt && !(flags & MNT_DETACH)) {
+	if (mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) {
 		/*
 		 * Special case for "unmounting" root ...
 		 * we just try to remount it readonly.
@@ -1559,17 +1559,17 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
 	while (p) {
 		q->mnt_ns = new_ns;
 		if (fs) {
-			if (p == fs->rootmnt) {
+			if (p == fs->root.mnt) {
 				rootmnt = p;
-				fs->rootmnt = mntget(q);
+				fs->root.mnt = mntget(q);
 			}
-			if (p == fs->pwdmnt) {
+			if (p == fs->pwd.mnt) {
 				pwdmnt = p;
-				fs->pwdmnt = mntget(q);
+				fs->pwd.mnt = mntget(q);
 			}
-			if (p == fs->altrootmnt) {
+			if (p == fs->altroot.mnt) {
 				altrootmnt = p;
-				fs->altrootmnt = mntget(q);
+				fs->altroot.mnt = mntget(q);
 			}
 		}
 		p = next_mnt(p, mnt_ns->root);
@@ -1653,18 +1653,15 @@ out1:
 void set_fs_root(struct fs_struct *fs, struct vfsmount *mnt,
 		 struct dentry *dentry)
 {
-	struct dentry *old_root;
-	struct vfsmount *old_rootmnt;
+	struct path old_root;
+
 	write_lock(&fs->lock);
 	old_root = fs->root;
-	old_rootmnt = fs->rootmnt;
-	fs->rootmnt = mntget(mnt);
-	fs->root = dget(dentry);
+	fs->root.mnt = mntget(mnt);
+	fs->root.dentry = dget(dentry);
 	write_unlock(&fs->lock);
-	if (old_root) {
-		dput(old_root);
-		mntput(old_rootmnt);
-	}
+	if (old_root.dentry)
+		path_put(&old_root);
 }
 
 /*
@@ -1674,20 +1671,16 @@ void set_fs_root(struct fs_struct *fs, struct vfsmount *mnt,
 void set_fs_pwd(struct fs_struct *fs, struct vfsmount *mnt,
 		struct dentry *dentry)
 {
-	struct dentry *old_pwd;
-	struct vfsmount *old_pwdmnt;
+	struct path old_pwd;
 
 	write_lock(&fs->lock);
 	old_pwd = fs->pwd;
-	old_pwdmnt = fs->pwdmnt;
-	fs->pwdmnt = mntget(mnt);
-	fs->pwd = dget(dentry);
+	fs->pwd.mnt = mntget(mnt);
+	fs->pwd.dentry = dget(dentry);
 	write_unlock(&fs->lock);
 
-	if (old_pwd) {
-		dput(old_pwd);
-		mntput(old_pwdmnt);
-	}
+	if (old_pwd.dentry)
+		path_put(&old_pwd);
 }
 
 static void chroot_fs_refs(struct nameidata *old_nd, struct nameidata *new_nd)
@@ -1702,12 +1695,12 @@ static void chroot_fs_refs(struct nameidata *old_nd, struct nameidata *new_nd)
 		if (fs) {
 			atomic_inc(&fs->count);
 			task_unlock(p);
-			if (fs->root == old_nd->path.dentry
-			    && fs->rootmnt == old_nd->path.mnt)
+			if (fs->root.dentry == old_nd->path.dentry
+			    && fs->root.mnt == old_nd->path.mnt)
 				set_fs_root(fs, new_nd->path.mnt,
 					    new_nd->path.dentry);
-			if (fs->pwd == old_nd->path.dentry
-			    && fs->pwdmnt == old_nd->path.mnt)
+			if (fs->pwd.dentry == old_nd->path.dentry
+			    && fs->pwd.mnt == old_nd->path.mnt)
 				set_fs_pwd(fs, new_nd->path.mnt,
 					   new_nd->path.dentry);
 			put_fs_struct(fs);
@@ -1773,8 +1766,8 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
 	}
 
 	read_lock(&current->fs->lock);
-	user_nd.path.mnt = mntget(current->fs->rootmnt);
-	user_nd.path.dentry = dget(current->fs->root);
+	user_nd.path = current->fs->root;
+	path_get(&current->fs->root);
 	read_unlock(&current->fs->lock);
 	down_write(&namespace_sem);
 	mutex_lock(&old_nd.path.dentry->d_inode->i_mutex);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index c742be4..080f1f6 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -165,8 +165,8 @@ static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfs
 	}
 	if (fs) {
 		read_lock(&fs->lock);
-		*mnt = mntget(fs->pwdmnt);
-		*dentry = dget(fs->pwd);
+		*mnt = mntget(fs->pwd.mnt);
+		*dentry = dget(fs->pwd.dentry);
 		read_unlock(&fs->lock);
 		result = 0;
 		put_fs_struct(fs);
@@ -186,8 +186,8 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf
 	}
 	if (fs) {
 		read_lock(&fs->lock);
-		*mnt = mntget(fs->rootmnt);
-		*dentry = dget(fs->root);
+		*mnt = mntget(fs->root.mnt);
+		*dentry = dget(fs->root.dentry);
 		read_unlock(&fs->lock);
 		result = 0;
 		put_fs_struct(fs);