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()
  ...

kernel/events/core.c

@@ -468,14 +468,13 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 {
 	struct perf_cgroup *cgrp;
 	struct cgroup_subsys_state *css;
-	struct file *file;
-	int ret = 0, fput_needed;
+	struct fd f = fdget(fd);
+	int ret = 0;
 
-	file = fget_light(fd, &fput_needed);
-	if (!file)
+	if (!f.file)
 		return -EBADF;
 
-	css = cgroup_css_from_dir(file, perf_subsys_id);
+	css = cgroup_css_from_dir(f.file, perf_subsys_id);
 	if (IS_ERR(css)) {
 		ret = PTR_ERR(css);
 		goto out;
@@ -501,7 +500,7 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 		ret = -EINVAL;
 	}
 out:
-	fput_light(file, fput_needed);
+	fdput(f);
 	return ret;
 }
 
@@ -3234,21 +3233,18 @@ unlock:
 
 static const struct file_operations perf_fops;
 
-static struct file *perf_fget_light(int fd, int *fput_needed)
+static inline int perf_fget_light(int fd, struct fd *p)
 {
-	struct file *file;
+	struct fd f = fdget(fd);
+	if (!f.file)
+		return -EBADF;
 
-	file = fget_light(fd, fput_needed);
-	if (!file)
-		return ERR_PTR(-EBADF);
-
-	if (file->f_op != &perf_fops) {
-		fput_light(file, *fput_needed);
-		*fput_needed = 0;
-		return ERR_PTR(-EBADF);
+	if (f.file->f_op != &perf_fops) {
+		fdput(f);
+		return -EBADF;
 	}
-
-	return file;
+	*p = f;
+	return 0;
 }
 
 static int perf_event_set_output(struct perf_event *event,
@@ -3280,22 +3276,19 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 	case PERF_EVENT_IOC_SET_OUTPUT:
 	{
-		struct file *output_file = NULL;
-		struct perf_event *output_event = NULL;
-		int fput_needed = 0;
 		int ret;
-
 		if (arg != -1) {
-			output_file = perf_fget_light(arg, &fput_needed);
-			if (IS_ERR(output_file))
-				return PTR_ERR(output_file);
-			output_event = output_file->private_data;
+			struct perf_event *output_event;
+			struct fd output;
+			ret = perf_fget_light(arg, &output);
+			if (ret)
+				return ret;
+			output_event = output.file->private_data;
+			ret = perf_event_set_output(event, output_event);
+			fdput(output);
+		} else {
+			ret = perf_event_set_output(event, NULL);
 		}
-
-		ret = perf_event_set_output(event, output_event);
-		if (output_event)
-			fput_light(output_file, fput_needed);
-
 		return ret;
 	}
 
@@ -6443,12 +6436,11 @@ SYSCALL_DEFINE5(perf_event_open,
 	struct perf_event_attr attr;
 	struct perf_event_context *ctx;
 	struct file *event_file = NULL;
-	struct file *group_file = NULL;
+	struct fd group = {NULL, 0};
 	struct task_struct *task = NULL;
 	struct pmu *pmu;
 	int event_fd;
 	int move_group = 0;
-	int fput_needed = 0;
 	int err;
 
 	/* for future expandability... */
@@ -6478,17 +6470,15 @@ SYSCALL_DEFINE5(perf_event_open,
 	if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
 		return -EINVAL;
 
-	event_fd = get_unused_fd_flags(O_RDWR);
+	event_fd = get_unused_fd();
 	if (event_fd < 0)
 		return event_fd;
 
 	if (group_fd != -1) {
-		group_file = perf_fget_light(group_fd, &fput_needed);
-		if (IS_ERR(group_file)) {
-			err = PTR_ERR(group_file);
+		err = perf_fget_light(group_fd, &group);
+		if (err)
 			goto err_fd;
-		}
-		group_leader = group_file->private_data;
+		group_leader = group.file->private_data;
 		if (flags & PERF_FLAG_FD_OUTPUT)
 			output_event = group_leader;
 		if (flags & PERF_FLAG_FD_NO_GROUP)
@@ -6664,7 +6654,7 @@ SYSCALL_DEFINE5(perf_event_open,
 	 * of the group leader will find the pointer to itself in
 	 * perf_group_detach().
 	 */
-	fput_light(group_file, fput_needed);
+	fdput(group);
 	fd_install(event_fd, event_file);
 	return event_fd;
 
@@ -6678,7 +6668,7 @@ err_task:
 	if (task)
 		put_task_struct(task);
 err_group_fd:
-	fput_light(group_file, fput_needed);
+	fdput(group);
 err_fd:
 	put_unused_fd(event_fd);
 	return err;