Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs updates from Al Viro:
 "The big thing in this pile is Eric's unmount-on-rmdir series; we
  finally have everything we need for that.  The final piece of prereqs
  is delayed mntput() - now filesystem shutdown always happens on
  shallow stack.

  Other than that, we have several new primitives for iov_iter (Matt
  Wilcox, culled from his XIP-related series) pushing the conversion to
  ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c
  cleanups and fixes (including the external name refcounting, which
  gives consistent behaviour of d_move() wrt procfs symlinks for long
  and short names alike) and assorted cleanups and fixes all over the
  place.

  This is just the first pile; there's a lot of stuff from various
  people that ought to go in this window.  Starting with
  unionmount/overlayfs mess...  ;-/"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits)
  fs/file_table.c: Update alloc_file() comment
  vfs: Deduplicate code shared by xattr system calls operating on paths
  reiserfs: remove pointless forward declaration of struct nameidata
  don't need that forward declaration of struct nameidata in dcache.h anymore
  take dname_external() into fs/dcache.c
  let path_init() failures treated the same way as subsequent link_path_walk()
  fix misuses of f_count() in ppp and netlink
  ncpfs: use list_for_each_entry() for d_subdirs walk
  vfs: move getname() from callers to do_mount()
  gfs2_atomic_open(): skip lookups on hashed dentry
  [infiniband] remove pointless assignments
  gadgetfs: saner API for gadgetfs_create_file()
  f_fs: saner API for ffs_sb_create_file()
  jfs: don't hash direct inode
  [s390] remove pointless assignment of ->f_op in vmlogrdr ->open()
  ecryptfs: ->f_op is never NULL
  android: ->f_op is never NULL
  nouveau: __iomem misannotations
  missing annotation in fs/file.c
  fs: namespace: suppress 'may be used uninitialized' warnings
  ...

1 files changed, 39 insertions, 77 deletions

diff --git a/fs/xattr.c b/fs/xattr.c
index c69e6d43a0d2..64e83efb742d 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -364,13 +364,12 @@ out:
 	return error;
 }
 
-SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
-		const char __user *, name, const void __user *, value,
-		size_t, size, int, flags)
+static int path_setxattr(const char __user *pathname,
+			 const char __user *name, const void __user *value,
+			 size_t size, int flags, unsigned int lookup_flags)
 {
 	struct path path;
 	int error;
-	unsigned int lookup_flags = LOOKUP_FOLLOW;
 retry:
 	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
 	if (error)
@@ -388,28 +387,18 @@ retry:
 	return error;
 }
 
+SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
+		const char __user *, name, const void __user *, value,
+		size_t, size, int, flags)
+{
+	return path_setxattr(pathname, name, value, size, flags, LOOKUP_FOLLOW);
+}
+
 SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname,
 		const char __user *, name, const void __user *, value,
 		size_t, size, int, flags)
 {
-	struct path path;
-	int error;
-	unsigned int lookup_flags = 0;
-retry:
-	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
-	if (error)
-		return error;
-	error = mnt_want_write(path.mnt);
-	if (!error) {
-		error = setxattr(path.dentry, name, value, size, flags);
-		mnt_drop_write(path.mnt);
-	}
-	path_put(&path);
-	if (retry_estale(error, lookup_flags)) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
-	}
-	return error;
+	return path_setxattr(pathname, name, value, size, flags, 0);
 }
 
 SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
@@ -481,12 +470,12 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
 	return error;
 }
 
-SYSCALL_DEFINE4(getxattr, const char __user *, pathname,
-		const char __user *, name, void __user *, value, size_t, size)
+static ssize_t path_getxattr(const char __user *pathname,
+			     const char __user *name, void __user *value,
+			     size_t size, unsigned int lookup_flags)
 {
 	struct path path;
 	ssize_t error;
-	unsigned int lookup_flags = LOOKUP_FOLLOW;
 retry:
 	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
 	if (error)
@@ -500,23 +489,16 @@ retry:
 	return error;
 }
 
+SYSCALL_DEFINE4(getxattr, const char __user *, pathname,
+		const char __user *, name, void __user *, value, size_t, size)
+{
+	return path_getxattr(pathname, name, value, size, LOOKUP_FOLLOW);
+}
+
 SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname,
 		const char __user *, name, void __user *, value, size_t, size)
 {
-	struct path path;
-	ssize_t error;
-	unsigned int lookup_flags = 0;
-retry:
-	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
-	if (error)
-		return error;
-	error = getxattr(path.dentry, name, value, size);
-	path_put(&path);
-	if (retry_estale(error, lookup_flags)) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
-	}
-	return error;
+	return path_getxattr(pathname, name, value, size, 0);
 }
 
 SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name,
@@ -571,12 +553,11 @@ listxattr(struct dentry *d, char __user *list, size_t size)
 	return error;
 }
 
-SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list,
-		size_t, size)
+static ssize_t path_listxattr(const char __user *pathname, char __user *list,
+			      size_t size, unsigned int lookup_flags)
 {
 	struct path path;
 	ssize_t error;
-	unsigned int lookup_flags = LOOKUP_FOLLOW;
 retry:
 	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
 	if (error)
@@ -590,23 +571,16 @@ retry:
 	return error;
 }
 
+SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list,
+		size_t, size)
+{
+	return path_listxattr(pathname, list, size, LOOKUP_FOLLOW);
+}
+
 SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list,
 		size_t, size)
 {
-	struct path path;
-	ssize_t error;
-	unsigned int lookup_flags = 0;
-retry:
-	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
-	if (error)
-		return error;
-	error = listxattr(path.dentry, list, size);
-	path_put(&path);
-	if (retry_estale(error, lookup_flags)) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
-	}
-	return error;
+	return path_listxattr(pathname, list, size, 0);
 }
 
 SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size)
@@ -640,12 +614,11 @@ removexattr(struct dentry *d, const char __user *name)
 	return vfs_removexattr(d, kname);
 }
 
-SYSCALL_DEFINE2(removexattr, const char __user *, pathname,
-		const char __user *, name)
+static int path_removexattr(const char __user *pathname,
+			    const char __user *name, unsigned int lookup_flags)
 {
 	struct path path;
 	int error;
-	unsigned int lookup_flags = LOOKUP_FOLLOW;
 retry:
 	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
 	if (error)
@@ -663,27 +636,16 @@ retry:
 	return error;
 }
 
+SYSCALL_DEFINE2(removexattr, const char __user *, pathname,
+		const char __user *, name)
+{
+	return path_removexattr(pathname, name, LOOKUP_FOLLOW);
+}
+
 SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname,
 		const char __user *, name)
 {
-	struct path path;
-	int error;
-	unsigned int lookup_flags = 0;
-retry:
-	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
-	if (error)
-		return error;
-	error = mnt_want_write(path.mnt);
-	if (!error) {
-		error = removexattr(path.dentry, name);
-		mnt_drop_write(path.mnt);
-	}
-	path_put(&path);
-	if (retry_estale(error, lookup_flags)) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
-	}
-	return error;
+	return path_removexattr(pathname, name, 0);
 }
 
 SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)