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()
  ...

1 files changed, 21 insertions, 78 deletions

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index c17de0db6736..9efeb6da48bc 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -21,6 +21,9 @@
 #include <linux/un.h>
 #include <linux/workqueue.h>
 #include <linux/mutex.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/file.h>
 #include <asm/uaccess.h>
 #include <asm/switch_to.h>
 
@@ -118,90 +121,38 @@ void mconsole_log(struct mc_request *req)
         mconsole_reply(req, "", 0, 0);
 }
 
-/* This is a more convoluted version of mconsole_proc, which has some stability
- * problems; however, we need it fixed, because it is expected that UML users
- * mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
- * show the real procfs content, not the ones from hppfs.*/
-#if 0
 void mconsole_proc(struct mc_request *req)
 {
         struct vfsmount *mnt = current->nsproxy->pid_ns->proc_mnt;
-        struct file *file;
-        int n;
-        char *ptr = req->request.data, *buf;
-        mm_segment_t old_fs = get_fs();
-
-        ptr += strlen("proc");
-        ptr = skip_spaces(ptr);
-
-        file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY);
-        if (IS_ERR(file)) {
-                mconsole_reply(req, "Failed to open file", 1, 0);
-                goto out;
-        }
-
-        buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-        if (buf == NULL) {
-                mconsole_reply(req, "Failed to allocate buffer", 1, 0);
-                goto out_fput;
-        }
-
-        if (file->f_op->read) {
-                do {
-                        loff_t pos;
-                        set_fs(KERNEL_DS);
-                        n = vfs_read(file, buf, PAGE_SIZE - 1, &pos);
-                        file_pos_write(file, pos);
-                        set_fs(old_fs);
-                        if (n >= 0) {
-                                buf[n] = '\0';
-                                mconsole_reply(req, buf, 0, (n > 0));
-                        }
-                        else {
-                                mconsole_reply(req, "Read of file failed",
-                                               1, 0);
-                                goto out_free;
-                        }
-                } while (n > 0);
-        }
-        else mconsole_reply(req, "", 0, 0);
-
- out_free:
-        kfree(buf);
- out_fput:
-        fput(file);
- out: ;
-}
-#endif
-
-void mconsole_proc(struct mc_request *req)
-{
-        char path[64];
         char *buf;
         int len;
-        int fd;
+        struct file *file;
         int first_chunk = 1;
         char *ptr = req->request.data;
 
         ptr += strlen("proc");
         ptr = skip_spaces(ptr);
-        snprintf(path, sizeof(path), "/proc/%s", ptr);
 
-        fd = sys_open(path, 0, 0);
-        if (fd < 0) {
+        file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY);
+        if (IS_ERR(file)) {
                 mconsole_reply(req, "Failed to open file", 1, 0);
-                printk(KERN_ERR "open %s: %d\n",path,fd);
+                printk(KERN_ERR "open /proc/%s: %ld\n", ptr, PTR_ERR(file));
                 goto out;
         }
 
         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
         if (buf == NULL) {
                 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
-                goto out_close;
+                goto out_fput;
         }
 
-        for (;;) {
-                len = sys_read(fd, buf, PAGE_SIZE-1);
+        do {
+                loff_t pos;
+                mm_segment_t old_fs = get_fs();
+                set_fs(KERNEL_DS);
+                len = vfs_read(file, buf, PAGE_SIZE - 1, &pos);
+                set_fs(old_fs);
+                file->f_pos = pos;
                 if (len < 0) {
                         mconsole_reply(req, "Read of file failed", 1, 0);
                         goto out_free;
@@ -211,22 +162,14 @@ void mconsole_proc(struct mc_request *req)
                         mconsole_reply(req, "\n", 0, 1);
                         first_chunk = 0;
                 }
-                if (len == PAGE_SIZE-1) {
-                        buf[len] = '\0';
-                        mconsole_reply(req, buf, 0, 1);
-                } else {
-                        buf[len] = '\0';
-                        mconsole_reply(req, buf, 0, 0);
-                        break;
-                }
-        }
-
+                buf[len] = '\0';
+                mconsole_reply(req, buf, 0, (len > 0));
+        } while (len > 0);
  out_free:
         kfree(buf);
- out_close:
-        sys_close(fd);
- out:
-        /* nothing */;
+ out_fput:
+        fput(file);
+ out: ;
 }
 
 #define UML_MCONSOLE_HELPTEXT \