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()
  ...

6 files changed, 83 insertions, 70 deletions

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 505f0ce3f10b..15656b8573f3 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -793,30 +793,28 @@ static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
 {
         struct p9_trans_fd *p;
-        int ret, fd;
+        struct file *file;
+        int ret;
 
         p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
         if (!p)
                 return -ENOMEM;
 
         csocket->sk->sk_allocation = GFP_NOIO;
-        fd = sock_map_fd(csocket, 0);
-        if (fd < 0) {
+        file = sock_alloc_file(csocket, 0, NULL);
+        if (IS_ERR(file)) {
                 pr_err("%s (%d): failed to map fd\n",
                        __func__, task_pid_nr(current));
                 sock_release(csocket);
                 kfree(p);
-                return fd;
+                return PTR_ERR(file);
         }
 
-        get_file(csocket->file);
-        get_file(csocket->file);
-        p->wr = p->rd = csocket->file;
+        get_file(file);
+        p->wr = p->rd = file;
         client->trans = p;
         client->status = Connected;
 
-        sys_close(fd);  /* still racy */
-
         p->rd->f_flags |= O_NONBLOCK;
 
         p->conn = p9_conn_create(client);
diff --git a/net/compat.c b/net/compat.c
index 74ed1d7a84a2..79ae88485001 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -301,8 +301,7 @@ void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
                         break;
                 }
                 /* Bump the usage count and install the file. */
-                get_file(fp[i]);
-                fd_install(new_fd, fp[i]);
+                fd_install(new_fd, get_file(fp[i]));
         }
 
         if (i > 0) {
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 4a83fb3c8e87..79285a36035f 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -239,38 +239,24 @@ out_free_devname:
         return ret;
 }
 
+static int update_netprio(const void *v, struct file *file, unsigned n)
+{
+        int err;
+        struct socket *sock = sock_from_file(file, &err);
+        if (sock)
+                sock->sk->sk_cgrp_prioidx = (u32)(unsigned long)v;
+        return 0;
+}
+
 void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
         struct task_struct *p;
+        void *v;
 
         cgroup_taskset_for_each(p, cgrp, tset) {
-                unsigned int fd;
-                struct fdtable *fdt;
-                struct files_struct *files;
-
                 task_lock(p);
-                files = p->files;
-                if (!files) {
-                        task_unlock(p);
-                        continue;
-                }
-
-                spin_lock(&files->file_lock);
-                fdt = files_fdtable(files);
-                for (fd = 0; fd < fdt->max_fds; fd++) {
-                        struct file *file;
-                        struct socket *sock;
-                        int err;
-
-                        file = fcheck_files(files, fd);
-                        if (!file)
-                                continue;
-
-                        sock = sock_from_file(file, &err);
-                        if (sock)
-                                sock_update_netprioidx(sock->sk, p);
-                }
-                spin_unlock(&files->file_lock);
+                v = (void *)(unsigned long)task_netprioidx(p);
+                iterate_fd(p->files, 0, update_netprio, v);
                 task_unlock(p);
         }
 }
diff --git a/net/core/scm.c b/net/core/scm.c
index 9c1c63da3ca8..ab570841a532 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -301,11 +301,10 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
                         break;
                 }
                 /* Bump the usage count and install the file. */
-                get_file(fp[i]);
                 sock = sock_from_file(fp[i], &err);
                 if (sock)
                         sock_update_netprioidx(sock->sk, current);
-                fd_install(new_fd, fp[i]);
+                fd_install(new_fd, get_file(fp[i]));
         }
 
         if (i > 0)
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index d37d24ff197f..59d16ea927f0 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -70,6 +70,7 @@
 #include <linux/init.h>
 #include <linux/crypto.h>
 #include <linux/slab.h>
+#include <linux/file.h>
 
 #include <net/ip.h>
 #include <net/icmp.h>
@@ -4292,6 +4293,7 @@ static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval
 {
         sctp_peeloff_arg_t peeloff;
         struct socket *newsock;
+        struct file *newfile;
         int retval = 0;
 
         if (len < sizeof(sctp_peeloff_arg_t))
@@ -4305,22 +4307,35 @@ static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval
                 goto out;
 
         /* Map the socket to an unused fd that can be returned to the user.  */
-        retval = sock_map_fd(newsock, 0);
+        retval = get_unused_fd();
         if (retval < 0) {
                 sock_release(newsock);
                 goto out;
         }
 
+        newfile = sock_alloc_file(newsock, 0, NULL);
+        if (unlikely(IS_ERR(newfile))) {
+                put_unused_fd(retval);
+                sock_release(newsock);
+                return PTR_ERR(newfile);
+        }
+
         SCTP_DEBUG_PRINTK("%s: sk: %p newsk: %p sd: %d\n",
                           __func__, sk, newsock->sk, retval);
 
         /* Return the fd mapped to the new socket.  */
+        if (put_user(len, optlen)) {
+                fput(newfile);
+                put_unused_fd(retval);
+                return -EFAULT;
+        }
         peeloff.sd = retval;
-        if (put_user(len, optlen))
+        if (copy_to_user(optval, &peeloff, len)) {
+                fput(newfile);
+                put_unused_fd(retval);
                 return -EFAULT;
-        if (copy_to_user(optval, &peeloff, len))
-                retval = -EFAULT;
-
+        }
+        fd_install(retval, newfile);
 out:
         return retval;
 }
diff --git a/net/socket.c b/net/socket.c
index 80dc7e84b046..d92c490e66fa 100644
--- a/net/socket.c
+++ b/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)