Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs namei updates from Al Viro:
 "Pathwalk-related stuff"

[ Audit-related cleanups, misc simplifications, and easier to follow
  nd->root refcounts     - Linus ]

* 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  devpts_pty_kill(): don't bother with d_delete()
  infiniband: don't bother with d_delete()
  hypfs: don't bother with d_delete()
  fs/namei.c: keep track of nd->root refcount status
  fs/namei.c: new helper - legitimize_root()
  kill the last users of user_{path,lpath,path_dir}()
  namei.h: get the comments on LOOKUP_... in sync with reality
  kill LOOKUP_NO_EVAL, don't bother including namei.h from audit.h
  audit_inode(): switch to passing AUDIT_INODE_...
  filename_mountpoint(): make LOOKUP_NO_EVAL unconditional there
  filename_lookup(): audit_inode() argument is always 0

arch/s390/hypfs/inode.c

@@ -76,7 +76,7 @@ static void hypfs_remove(struct dentry *dentry)
 		else
 			simple_unlink(d_inode(parent), dentry);
 	}
-	d_delete(dentry);
+	d_drop(dentry);
 	dput(dentry);
 	inode_unlock(d_inode(parent));
 }

drivers/infiniband/hw/qib/qib_fs.c

@@ -493,7 +493,7 @@ static int remove_device_files(struct super_block *sb,
 	remove_file(dir, "flash");
 	inode_unlock(d_inode(dir));
 	ret = simple_rmdir(d_inode(root), dir);
-	d_delete(dir);
+	d_drop(dir);
 	dput(dir);
 
 bail:

fs/coda/pioctl.c

@@ -63,11 +63,8 @@ static long coda_pioctl(struct file *filp, unsigned int cmd,
 	 * Look up the pathname. Note that the pathname is in
 	 * user memory, and namei takes care of this
 	 */
-	if (data.follow)
-		error = user_path(data.path, &path);
-	else
-		error = user_lpath(data.path, &path);
-
+	error = user_path_at(AT_FDCWD, data.path,
+			     data.follow ? LOOKUP_FOLLOW : 0, &path);
 	if (error)
 		return error;
 

fs/devpts/inode.c

@@ -622,7 +622,7 @@ void devpts_pty_kill(struct dentry *dentry)
 	dentry->d_fsdata = NULL;
 	drop_nlink(dentry->d_inode);
 	fsnotify_unlink(d_inode(dentry->d_parent), dentry);
-	d_delete(dentry);
+	d_drop(dentry);
 	dput(dentry);	/* d_alloc_name() in devpts_pty_new() */
 }
 

fs/namei.c

@@ -596,14 +596,12 @@ static void terminate_walk(struct nameidata *nd)
 		path_put(&nd->path);
 		for (i = 0; i < nd->depth; i++)
 			path_put(&nd->stack[i].link);
-		if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
+		if (nd->flags & LOOKUP_ROOT_GRABBED) {
 			path_put(&nd->root);
-			nd->root.mnt = NULL;
+			nd->flags &= ~LOOKUP_ROOT_GRABBED;
 		}
 	} else {
 		nd->flags &= ~LOOKUP_RCU;
-		if (!(nd->flags & LOOKUP_ROOT))
-			nd->root.mnt = NULL;
 		rcu_read_unlock();
 	}
 	nd->depth = 0;
@@ -641,6 +639,14 @@ static bool legitimize_links(struct nameidata *nd)
 	return true;
 }
 
+static bool legitimize_root(struct nameidata *nd)
+{
+	if (!nd->root.mnt || (nd->flags & LOOKUP_ROOT))
+		return true;
+	nd->flags |= LOOKUP_ROOT_GRABBED;
+	return legitimize_path(nd, &nd->root, nd->root_seq);
+}
+
 /*
  * Path walking has 2 modes, rcu-walk and ref-walk (see
  * Documentation/filesystems/path-lookup.txt).  In situations when we can't
@@ -671,23 +677,18 @@ static int unlazy_walk(struct nameidata *nd)
 
 	nd->flags &= ~LOOKUP_RCU;
 	if (unlikely(!legitimize_links(nd)))
-		goto out2;
-	if (unlikely(!legitimize_path(nd, &nd->path, nd->seq)))
 		goto out1;
-	if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
-		if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq)))
+	if (unlikely(!legitimize_path(nd, &nd->path, nd->seq)))
+		goto out;
+	if (unlikely(!legitimize_root(nd)))
 		goto out;
-	}
 	rcu_read_unlock();
 	BUG_ON(nd->inode != parent->d_inode);
 	return 0;
 
-out2:
+out1:
 	nd->path.mnt = NULL;
 	nd->path.dentry = NULL;
-out1:
-	if (!(nd->flags & LOOKUP_ROOT))
-		nd->root.mnt = NULL;
 out:
 	rcu_read_unlock();
 	return -ECHILD;
@@ -727,23 +728,14 @@ static int unlazy_child(struct nameidata *nd, struct dentry *dentry, unsigned se
 	 */
 	if (unlikely(!lockref_get_not_dead(&dentry->d_lockref)))
 		goto out;
-	if (unlikely(read_seqcount_retry(&dentry->d_seq, seq))) {
-		rcu_read_unlock();
-		dput(dentry);
-		goto drop_root_mnt;
-	}
+	if (unlikely(read_seqcount_retry(&dentry->d_seq, seq)))
+		goto out_dput;
 	/*
 	 * Sequence counts matched. Now make sure that the root is
 	 * still valid and get it if required.
 	 */
-	if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
-		if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq))) {
-			rcu_read_unlock();
-			dput(dentry);
-			return -ECHILD;
-		}
-	}
-
+	if (unlikely(!legitimize_root(nd)))
+		goto out_dput;
 	rcu_read_unlock();
 	return 0;
 
@@ -753,9 +745,10 @@ static int unlazy_child(struct nameidata *nd, struct dentry *dentry, unsigned se
 	nd->path.dentry = NULL;
 out:
 	rcu_read_unlock();
-drop_root_mnt:
-	if (!(nd->flags & LOOKUP_ROOT))
-		nd->root.mnt = NULL;
+	return -ECHILD;
+out_dput:
+	rcu_read_unlock();
+	dput(dentry);
 	return -ECHILD;
 }
 
@@ -819,6 +812,7 @@ static void set_root(struct nameidata *nd)
 		} while (read_seqcount_retry(&fs->seq, seq));
 	} else {
 		get_fs_root(fs, &nd->root);
+		nd->flags |= LOOKUP_ROOT_GRABBED;
 	}
 }
 
@@ -1735,8 +1729,6 @@ static int pick_link(struct nameidata *nd, struct path *link,
 				nd->flags &= ~LOOKUP_RCU;
 				nd->path.mnt = NULL;
 				nd->path.dentry = NULL;
-				if (!(nd->flags & LOOKUP_ROOT))
-					nd->root.mnt = NULL;
 				rcu_read_unlock();
 			} else if (likely(unlazy_walk(nd)) == 0)
 				error = nd_alloc_stack(nd);
@@ -2350,7 +2342,7 @@ int filename_lookup(int dfd, struct filename *name, unsigned flags,
 		retval = path_lookupat(&nd, flags | LOOKUP_REVAL, path);
 
 	if (likely(!retval))
-		audit_inode(name, path->dentry, flags & LOOKUP_PARENT);
+		audit_inode(name, path->dentry, 0);
 	restore_nameidata();
 	putname(name);
 	return retval;
@@ -2391,7 +2383,7 @@ static struct filename *filename_parentat(int dfd, struct filename *name,
 	if (likely(!retval)) {
 		*last = nd.last;
 		*type = nd.last_type;
-		audit_inode(name, parent->dentry, LOOKUP_PARENT);
+		audit_inode(name, parent->dentry, AUDIT_INODE_PARENT);
 	} else {
 		putname(name);
 		name = ERR_PTR(retval);
@@ -2718,7 +2710,7 @@ filename_mountpoint(int dfd, struct filename *name, struct path *path,
 	if (unlikely(error == -ESTALE))
 		error = path_mountpoint(&nd, flags | LOOKUP_REVAL, path);
 	if (likely(!error))
-		audit_inode(name, path->dentry, flags & LOOKUP_NO_EVAL);
+		audit_inode(name, path->dentry, AUDIT_INODE_NOEVAL);
 	restore_nameidata();
 	putname(name);
 	return error;
@@ -3299,7 +3291,7 @@ static int do_last(struct nameidata *nd,
 		if (error)
 			return error;
 
-		audit_inode(nd->name, dir, LOOKUP_PARENT);
+		audit_inode(nd->name, dir, AUDIT_INODE_PARENT);
 		/* trailing slashes? */
 		if (unlikely(nd->last.name[nd->last.len]))
 			return -EISDIR;

fs/namespace.c

@@ -1675,8 +1675,6 @@ int ksys_umount(char __user *name, int flags)
 	if (!(flags & UMOUNT_NOFOLLOW))
 		lookup_flags |= LOOKUP_FOLLOW;
 
-	lookup_flags |= LOOKUP_NO_EVAL;
-
 	retval = user_path_mountpoint_at(AT_FDCWD, name, lookup_flags, &path);
 	if (retval)
 		goto out;
@@ -3046,7 +3044,7 @@ long do_mount(const char *dev_name, const char __user *dir_name,
 		return -EINVAL;
 
 	/* ... and get the mountpoint */
-	retval = user_path(dir_name, &path);
+	retval = user_path_at(AT_FDCWD, dir_name, LOOKUP_FOLLOW, &path);
 	if (retval)
 		return retval;
 
@@ -3593,11 +3591,13 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
 	if (!may_mount())
 		return -EPERM;
 
-	error = user_path_dir(new_root, &new);
+	error = user_path_at(AT_FDCWD, new_root,
+			     LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &new);
 	if (error)
 		goto out0;
 
-	error = user_path_dir(put_old, &old);
+	error = user_path_at(AT_FDCWD, put_old,
+			     LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &old);
 	if (error)
 		goto out1;
 

fs/nfs/nfstrace.h

@@ -207,7 +207,6 @@ TRACE_DEFINE_ENUM(LOOKUP_PARENT);
 TRACE_DEFINE_ENUM(LOOKUP_REVAL);
 TRACE_DEFINE_ENUM(LOOKUP_RCU);
 TRACE_DEFINE_ENUM(LOOKUP_NO_REVAL);
-TRACE_DEFINE_ENUM(LOOKUP_NO_EVAL);
 TRACE_DEFINE_ENUM(LOOKUP_OPEN);
 TRACE_DEFINE_ENUM(LOOKUP_CREATE);
 TRACE_DEFINE_ENUM(LOOKUP_EXCL);
@@ -226,7 +225,6 @@ TRACE_DEFINE_ENUM(LOOKUP_DOWN);
 			{ LOOKUP_REVAL, "REVAL" }, \
 			{ LOOKUP_RCU, "RCU" }, \
 			{ LOOKUP_NO_REVAL, "NO_REVAL" }, \
-			{ LOOKUP_NO_EVAL, "NO_EVAL" }, \
 			{ LOOKUP_OPEN, "OPEN" }, \
 			{ LOOKUP_CREATE, "CREATE" }, \
 			{ LOOKUP_EXCL, "EXCL" }, \

fs/xfs/xfs_ioctl.c

@@ -67,7 +67,7 @@ xfs_find_handle(
 			return -EBADF;
 		inode = file_inode(f.file);
 	} else {
-		error = user_lpath((const char __user *)hreq->path, &path);
+		error = user_path_at(AT_FDCWD, hreq->path, 0, &path);
 		if (error)
 			return error;
 		inode = d_inode(path.dentry);

include/linux/audit.h

@@ -11,7 +11,6 @@
 
 #include <linux/sched.h>
 #include <linux/ptrace.h>
-#include <linux/namei.h>  /* LOOKUP_* */
 #include <uapi/linux/audit.h>
 
 #define AUDIT_INO_UNSET ((unsigned long)-1)
@@ -252,6 +251,10 @@ static inline int audit_signal_info(int sig, struct task_struct *t)
 #define audit_is_compat(arch)  false
 #endif
 
+#define AUDIT_INODE_PARENT	1	/* dentry represents the parent */
+#define AUDIT_INODE_HIDDEN	2	/* audit record should be hidden */
+#define AUDIT_INODE_NOEVAL	4	/* audit record incomplete */
+
 #ifdef CONFIG_AUDITSYSCALL
 #include <asm/syscall.h> /* for syscall_get_arch() */
 
@@ -265,9 +268,6 @@ extern void __audit_syscall_exit(int ret_success, long ret_value);
 extern struct filename *__audit_reusename(const __user char *uptr);
 extern void __audit_getname(struct filename *name);
 
-#define AUDIT_INODE_PARENT	1	/* dentry represents the parent */
-#define AUDIT_INODE_HIDDEN	2	/* audit record should be hidden */
-#define AUDIT_INODE_NOEVAL	4	/* audit record incomplete */
 extern void __audit_inode(struct filename *name, const struct dentry *dentry,
 				unsigned int flags);
 extern void __audit_file(const struct file *);
@@ -328,16 +328,9 @@ static inline void audit_getname(struct filename *name)
 }
 static inline void audit_inode(struct filename *name,
 				const struct dentry *dentry,
-				unsigned int flags) {
-	if (unlikely(!audit_dummy_context())) {
-		unsigned int aflags = 0;
-
-		if (flags & LOOKUP_PARENT)
-			aflags |= AUDIT_INODE_PARENT;
-		if (flags & LOOKUP_NO_EVAL)
-			aflags |= AUDIT_INODE_NOEVAL;
+				unsigned int aflags) {
+	if (unlikely(!audit_dummy_context()))
 		__audit_inode(name, dentry, aflags);
-	}
 }
 static inline void audit_file(struct file *file)
 {
@@ -561,7 +554,7 @@ static inline void __audit_inode_child(struct inode *parent,
 { }
 static inline void audit_inode(struct filename *name,
 				const struct dentry *dentry,
-				unsigned int parent)
+				unsigned int aflags)
 { }
 static inline void audit_file(struct file *file)
 {

include/linux/namei.h

@@ -16,39 +16,28 @@ enum { MAX_NESTED_LINKS = 8 };
  */
 enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
 
-/*
- * The bitmask for a lookup event:
- *  - follow links at the end
- *  - require a directory
- *  - ending slashes ok even for nonexistent files
- *  - internal "there are more path components" flag
- *  - dentry cache is untrusted; force a real lookup
- *  - suppress terminal automount
- *  - skip revalidation
- *  - don't fetch xattrs on audit_inode
- */
-#define LOOKUP_FOLLOW		0x0001
-#define LOOKUP_DIRECTORY	0x0002
-#define LOOKUP_AUTOMOUNT	0x0004
-
+/* pathwalk mode */
+#define LOOKUP_FOLLOW		0x0001	/* follow links at the end */
+#define LOOKUP_DIRECTORY	0x0002	/* require a directory */
+#define LOOKUP_AUTOMOUNT	0x0004  /* force terminal automount */
+#define LOOKUP_EMPTY		0x4000	/* accept empty path [user_... only] */
+#define LOOKUP_DOWN		0x8000	/* follow mounts in the starting point */
+
+#define LOOKUP_REVAL		0x0020	/* tell ->d_revalidate() to trust no cache */
+#define LOOKUP_RCU		0x0040	/* RCU pathwalk mode; semi-internal */
+
+/* These tell filesystem methods that we are dealing with the final component... */
+#define LOOKUP_OPEN		0x0100	/* ... in open */
+#define LOOKUP_CREATE		0x0200	/* ... in object creation */
+#define LOOKUP_EXCL		0x0400	/* ... in exclusive creation */
+#define LOOKUP_RENAME_TARGET	0x0800	/* ... in destination of rename() */
+
+/* internal use only */
 #define LOOKUP_PARENT		0x0010
-#define LOOKUP_REVAL		0x0020
-#define LOOKUP_RCU		0x0040
 #define LOOKUP_NO_REVAL		0x0080
-#define LOOKUP_NO_EVAL		0x0100
-
-/*
- * Intent data
- */
-#define LOOKUP_OPEN		0x0100
-#define LOOKUP_CREATE		0x0200
-#define LOOKUP_EXCL		0x0400
-#define LOOKUP_RENAME_TARGET	0x0800
-
 #define LOOKUP_JUMPED		0x1000
 #define LOOKUP_ROOT		0x2000
-#define LOOKUP_EMPTY		0x4000
-#define LOOKUP_DOWN		0x8000
+#define LOOKUP_ROOT_GRABBED	0x0008
 
 extern int path_pts(struct path *path);
 
@@ -60,22 +49,6 @@ static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
 	return user_path_at_empty(dfd, name, flags, path, NULL);
 }
 
-static inline int user_path(const char __user *name, struct path *path)
-{
-	return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
-}
-
-static inline int user_lpath(const char __user *name, struct path *path)
-{
-	return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
-}
-
-static inline int user_path_dir(const char __user *name, struct path *path)
-{
-	return user_path_at_empty(AT_FDCWD, name,
-				  LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
-}
-
 extern int kern_path(const char *, unsigned, struct path *);
 
 extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);