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

Pull vfs update from Al Viro:

 - big one - consolidation of descriptor-related logics; almost all of
   that is moved to fs/file.c

   (BTW, I'm seriously tempted to rename the result to fd.c.  As it is,
   we have a situation when file_table.c is about handling of struct
   file and file.c is about handling of descriptor tables; the reasons
   are historical - file_table.c used to be about a static array of
   struct file we used to have way back).

   A lot of stray ends got cleaned up and converted to saner primitives,
   disgusting mess in android/binder.c is still disgusting, but at least
   doesn't poke so much in descriptor table guts anymore.  A bunch of
   relatively minor races got fixed in process, plus an ext4 struct file
   leak.

 - related thing - fget_light() partially unuglified; see fdget() in
   there (and yes, it generates the code as good as we used to have).

 - also related - bits of Cyrill's procfs stuff that got entangled into
   that work; _not_ all of it, just the initial move to fs/proc/fd.c and
   switch of fdinfo to seq_file.

 - Alex's fs/coredump.c spiltoff - the same story, had been easier to
   take that commit than mess with conflicts.  The rest is a separate
   pile, this was just a mechanical code movement.

 - a few misc patches all over the place.  Not all for this cycle,
   there'll be more (and quite a few currently sit in akpm's tree)."

Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
  MAX_LFS_FILESIZE should be a loff_t
  compat: fs: Generic compat_sys_sendfile implementation
  fs: push rcu_barrier() from deactivate_locked_super() to filesystems
  btrfs: reada_extent doesn't need kref for refcount
  coredump: move core dump functionality into its own file
  coredump: prevent double-free on an error path in core dumper
  usb/gadget: fix misannotations
  fcntl: fix misannotations
  ceph: don't abuse d_delete() on failure exits
  hypfs: ->d_parent is never NULL or negative
  vfs: delete surplus inode NULL check
  switch simple cases of fget_light to fdget
  new helpers: fdget()/fdput()
  switch o2hb_region_dev_write() to fget_light()
  proc_map_files_readdir(): don't bother with grabbing files
  make get_file() return its argument
  vhost_set_vring(): turn pollstart/pollstop into bool
  switch prctl_set_mm_exe_file() to fget_light()
  switch xfs_find_handle() to fget_light()
  switch xfs_swapext() to fget_light()
  ...

net/socket.c

@@ -347,17 +347,11 @@ static struct file_system_type sock_fs_type = {
  *	but we take care of internal coherence yet.
  */
 
-static int sock_alloc_file(struct socket *sock, struct file **f, int flags,
-			   const char *dname)
+struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
 {
 	struct qstr name = { .name = "" };
 	struct path path;
 	struct file *file;
-	int fd;
-
-	fd = get_unused_fd_flags(flags);
-	if (unlikely(fd < 0))
-		return fd;
 
 	if (dname) {
 		name.name = dname;
@@ -367,10 +361,8 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags,
 		name.len = strlen(name.name);
 	}
 	path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name);
-	if (unlikely(!path.dentry)) {
-		put_unused_fd(fd);
-		return -ENOMEM;
-	}
+	if (unlikely(!path.dentry))
+		return ERR_PTR(-ENOMEM);
 	path.mnt = mntget(sock_mnt);
 
 	d_instantiate(path.dentry, SOCK_INODE(sock));
@@ -382,30 +374,33 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags,
 		/* drop dentry, keep inode */
 		ihold(path.dentry->d_inode);
 		path_put(&path);
-		put_unused_fd(fd);
-		return -ENFILE;
+		return ERR_PTR(-ENFILE);
 	}
 
 	sock->file = file;
 	file->f_flags = O_RDWR | (flags & O_NONBLOCK);
 	file->f_pos = 0;
 	file->private_data = sock;
-
-	*f = file;
-	return fd;
+	return file;
 }
+EXPORT_SYMBOL(sock_alloc_file);
 
-int sock_map_fd(struct socket *sock, int flags)
+static int sock_map_fd(struct socket *sock, int flags)
 {
 	struct file *newfile;
-	int fd = sock_alloc_file(sock, &newfile, flags, NULL);
+	int fd = get_unused_fd_flags(flags);
+	if (unlikely(fd < 0))
+		return fd;
 
-	if (likely(fd >= 0))
+	newfile = sock_alloc_file(sock, flags, NULL);
+	if (likely(!IS_ERR(newfile))) {
 		fd_install(fd, newfile);
+		return fd;
+	}
 
-	return fd;
+	put_unused_fd(fd);
+	return PTR_ERR(newfile);
 }
-EXPORT_SYMBOL(sock_map_fd);
 
 struct socket *sock_from_file(struct file *file, int *err)
 {
@@ -1466,17 +1461,32 @@ SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
 	if (err < 0)
 		goto out_release_both;
 
-	fd1 = sock_alloc_file(sock1, &newfile1, flags, NULL);
+	fd1 = get_unused_fd_flags(flags);
 	if (unlikely(fd1 < 0)) {
 		err = fd1;
 		goto out_release_both;
 	}
-
-	fd2 = sock_alloc_file(sock2, &newfile2, flags, NULL);
+	fd2 = get_unused_fd_flags(flags);
 	if (unlikely(fd2 < 0)) {
 		err = fd2;
+		put_unused_fd(fd1);
+		goto out_release_both;
+	}
+
+	newfile1 = sock_alloc_file(sock1, flags, NULL);
+	if (unlikely(IS_ERR(newfile1))) {
+		err = PTR_ERR(newfile1);
+		put_unused_fd(fd1);
+		put_unused_fd(fd2);
+		goto out_release_both;
+	}
+
+	newfile2 = sock_alloc_file(sock2, flags, NULL);
+	if (IS_ERR(newfile2)) {
+		err = PTR_ERR(newfile2);
 		fput(newfile1);
 		put_unused_fd(fd1);
+		put_unused_fd(fd2);
 		sock_release(sock2);
 		goto out;
 	}
@@ -1608,13 +1618,19 @@ SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
 	 */
 	__module_get(newsock->ops->owner);
 
-	newfd = sock_alloc_file(newsock, &newfile, flags,
-				sock->sk->sk_prot_creator->name);
+	newfd = get_unused_fd_flags(flags);
 	if (unlikely(newfd < 0)) {
 		err = newfd;
 		sock_release(newsock);
 		goto out_put;
 	}
+	newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);
+	if (unlikely(IS_ERR(newfile))) {
+		err = PTR_ERR(newfile);
+		put_unused_fd(newfd);
+		sock_release(newsock);
+		goto out_put;
+	}
 
 	err = security_socket_accept(sock, newsock);
 	if (err)