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

Pull vfs updates from Al Viro:
 "The first vfs pile, with deep apologies for being very late in this
  window.

  Assorted cleanups and fixes, plus a large preparatory part of iov_iter
  work.  There's a lot more of that, but it'll probably go into the next
  merge window - it *does* shape up nicely, removes a lot of
  boilerplate, gets rid of locking inconsistencie between aio_write and
  splice_write and I hope to get Kent's direct-io rewrite merged into
  the same queue, but some of the stuff after this point is having
  (mostly trivial) conflicts with the things already merged into
  mainline and with some I want more testing.

  This one passes LTP and xfstests without regressions, in addition to
  usual beating.  BTW, readahead02 in ltp syscalls testsuite has started
  giving failures since "mm/readahead.c: fix readahead failure for
  memoryless NUMA nodes and limit readahead pages" - might be a false
  positive, might be a real regression..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  missing bits of "splice: fix racy pipe->buffers uses"
  cifs: fix the race in cifs_writev()
  ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
  kill generic_file_buffered_write()
  ocfs2_file_aio_write(): switch to generic_perform_write()
  ceph_aio_write(): switch to generic_perform_write()
  xfs_file_buffered_aio_write(): switch to generic_perform_write()
  export generic_perform_write(), start getting rid of generic_file_buffer_write()
  generic_file_direct_write(): get rid of ppos argument
  btrfs_file_aio_write(): get rid of ppos
  kill the 5th argument of generic_file_buffered_write()
  kill the 4th argument of __generic_file_aio_write()
  lustre: don't open-code kernel_recvmsg()
  ocfs2: don't open-code kernel_recvmsg()
  drbd: don't open-code kernel_recvmsg()
  constify blk_rq_map_user_iov() and friends
  lustre: switch to kernel_sendmsg()
  ocfs2: don't open-code kernel_sendmsg()
  take iov_iter stuff to mm/iov_iter.c
  process_vm_access: tidy up a bit
  ...

1 files changed, 16 insertions, 52 deletions

diff --git a/fs/open.c b/fs/open.c
index 631aea815def..3d30eb1fc95e 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -655,35 +655,6 @@ out:
 	return error;
 }
 
-/*
- * You have to be very careful that these write
- * counts get cleaned up in error cases and
- * upon __fput().  This should probably never
- * be called outside of __dentry_open().
- */
-static inline int __get_file_write_access(struct inode *inode,
-					  struct vfsmount *mnt)
-{
-	int error;
-	error = get_write_access(inode);
-	if (error)
-		return error;
-	/*
-	 * Do not take mount writer counts on
-	 * special files since no writes to
-	 * the mount itself will occur.
-	 */
-	if (!special_file(inode->i_mode)) {
-		/*
-		 * Balanced in __fput()
-		 */
-		error = __mnt_want_write(mnt);
-		if (error)
-			put_write_access(inode);
-	}
-	return error;
-}
-
 int open_check_o_direct(struct file *f)
 {
 	/* NB: we're sure to have correct a_ops only after f_op->open */
@@ -708,26 +679,28 @@ static int do_dentry_open(struct file *f,
 	f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK |
 				FMODE_PREAD | FMODE_PWRITE;
 
-	if (unlikely(f->f_flags & O_PATH))
-		f->f_mode = FMODE_PATH;
-
 	path_get(&f->f_path);
 	inode = f->f_inode = f->f_path.dentry->d_inode;
-	if (f->f_mode & FMODE_WRITE) {
-		error = __get_file_write_access(inode, f->f_path.mnt);
-		if (error)
-			goto cleanup_file;
-		if (!special_file(inode->i_mode))
-			file_take_write(f);
-	}
-
 	f->f_mapping = inode->i_mapping;
 
-	if (unlikely(f->f_mode & FMODE_PATH)) {
+	if (unlikely(f->f_flags & O_PATH)) {
+		f->f_mode = FMODE_PATH;
 		f->f_op = &empty_fops;
 		return 0;
 	}
 
+	if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
+		error = get_write_access(inode);
+		if (unlikely(error))
+			goto cleanup_file;
+		error = __mnt_want_write(f->f_path.mnt);
+		if (unlikely(error)) {
+			put_write_access(inode);
+			goto cleanup_file;
+		}
+		f->f_mode |= FMODE_WRITER;
+	}
+
 	/* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */
 	if (S_ISREG(inode->i_mode))
 		f->f_mode |= FMODE_ATOMIC_POS;
@@ -764,18 +737,9 @@ static int do_dentry_open(struct file *f,
 
 cleanup_all:
 	fops_put(f->f_op);
-	if (f->f_mode & FMODE_WRITE) {
+	if (f->f_mode & FMODE_WRITER) {
 		put_write_access(inode);
-		if (!special_file(inode->i_mode)) {
-			/*
-			 * We don't consider this a real
-			 * mnt_want/drop_write() pair
-			 * because it all happenend right
-			 * here, so just reset the state.
-			 */
-			file_reset_write(f);
-			__mnt_drop_write(f->f_path.mnt);
-		}
+		__mnt_drop_write(f->f_path.mnt);
 	}
 cleanup_file:
 	path_put(&f->f_path);