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, 25 insertions, 101 deletions

diff --git a/fs/splice.c b/fs/splice.c
index 12028fa..9bc07d2 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -136,8 +136,6 @@ error:
 
 const struct pipe_buf_operations page_cache_pipe_buf_ops = {
 	.can_merge = 0,
-	.map = generic_pipe_buf_map,
-	.unmap = generic_pipe_buf_unmap,
 	.confirm = page_cache_pipe_buf_confirm,
 	.release = page_cache_pipe_buf_release,
 	.steal = page_cache_pipe_buf_steal,
@@ -156,8 +154,6 @@ static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,
 
 static const struct pipe_buf_operations user_page_pipe_buf_ops = {
 	.can_merge = 0,
-	.map = generic_pipe_buf_map,
-	.unmap = generic_pipe_buf_unmap,
 	.confirm = generic_pipe_buf_confirm,
 	.release = page_cache_pipe_buf_release,
 	.steal = user_page_pipe_buf_steal,
@@ -547,8 +543,6 @@ EXPORT_SYMBOL(generic_file_splice_read);
 
 static const struct pipe_buf_operations default_pipe_buf_ops = {
 	.can_merge = 0,
-	.map = generic_pipe_buf_map,
-	.unmap = generic_pipe_buf_unmap,
 	.confirm = generic_pipe_buf_confirm,
 	.release = generic_pipe_buf_release,
 	.steal = generic_pipe_buf_steal,
@@ -564,8 +558,6 @@ static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
 /* Pipe buffer operations for a socket and similar. */
 const struct pipe_buf_operations nosteal_pipe_buf_ops = {
 	.can_merge = 0,
-	.map = generic_pipe_buf_map,
-	.unmap = generic_pipe_buf_unmap,
 	.confirm = generic_pipe_buf_confirm,
 	.release = generic_pipe_buf_release,
 	.steal = generic_pipe_buf_nosteal,
@@ -767,13 +759,13 @@ int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 		goto out;
 
 	if (buf->page != page) {
-		char *src = buf->ops->map(pipe, buf, 1);
+		char *src = kmap_atomic(buf->page);
 		char *dst = kmap_atomic(page);
 
 		memcpy(dst + offset, src + buf->offset, this_len);
 		flush_dcache_page(page);
 		kunmap_atomic(dst);
-		buf->ops->unmap(pipe, buf, src);
+		kunmap_atomic(src);
 	}
 	ret = pagecache_write_end(file, mapping, sd->pos, this_len, this_len,
 				page, fsdata);
@@ -1067,9 +1059,9 @@ static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 	void *data;
 	loff_t tmp = sd->pos;
 
-	data = buf->ops->map(pipe, buf, 0);
+	data = kmap(buf->page);
 	ret = __kernel_write(sd->u.file, data + buf->offset, sd->len, &tmp);
-	buf->ops->unmap(pipe, buf, data);
+	kunmap(buf->page);
 
 	return ret;
 }
@@ -1528,116 +1520,48 @@ static int get_iovec_page_array(const struct iovec __user *iov,
 static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 			struct splice_desc *sd)
 {
-	char *src;
-	int ret;
-
-	/*
-	 * See if we can use the atomic maps, by prefaulting in the
-	 * pages and doing an atomic copy
-	 */
-	if (!fault_in_pages_writeable(sd->u.userptr, sd->len)) {
-		src = buf->ops->map(pipe, buf, 1);
-		ret = __copy_to_user_inatomic(sd->u.userptr, src + buf->offset,
-							sd->len);
-		buf->ops->unmap(pipe, buf, src);
-		if (!ret) {
-			ret = sd->len;
-			goto out;
-		}
-	}
-
-	/*
-	 * No dice, use slow non-atomic map and copy
- 	 */
-	src = buf->ops->map(pipe, buf, 0);
-
-	ret = sd->len;
-	if (copy_to_user(sd->u.userptr, src + buf->offset, sd->len))
-		ret = -EFAULT;
-
-	buf->ops->unmap(pipe, buf, src);
-out:
-	if (ret > 0)
-		sd->u.userptr += ret;
-	return ret;
+	int n = copy_page_to_iter(buf->page, buf->offset, sd->len, sd->u.data);
+	return n == sd->len ? n : -EFAULT;
 }
 
 /*
  * For lack of a better implementation, implement vmsplice() to userspace
  * as a simple copy of the pipes pages to the user iov.
  */
-static long vmsplice_to_user(struct file *file, const struct iovec __user *iov,
+static long vmsplice_to_user(struct file *file, const struct iovec __user *uiov,
 			     unsigned long nr_segs, unsigned int flags)
 {
 	struct pipe_inode_info *pipe;
 	struct splice_desc sd;
-	ssize_t size;
-	int error;
 	long ret;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	ssize_t count = 0;
 
 	pipe = get_pipe_info(file);
 	if (!pipe)
 		return -EBADF;
 
-	pipe_lock(pipe);
-
-	error = ret = 0;
-	while (nr_segs) {
-		void __user *base;
-		size_t len;
-
-		/*
-		 * Get user address base and length for this iovec.
-		 */
-		error = get_user(base, &iov->iov_base);
-		if (unlikely(error))
-			break;
-		error = get_user(len, &iov->iov_len);
-		if (unlikely(error))
-			break;
-
-		/*
-		 * Sanity check this iovec. 0 read succeeds.
-		 */
-		if (unlikely(!len))
-			break;
-		if (unlikely(!base)) {
-			error = -EFAULT;
-			break;
-		}
-
-		if (unlikely(!access_ok(VERIFY_WRITE, base, len))) {
-			error = -EFAULT;
-			break;
-		}
-
-		sd.len = 0;
-		sd.total_len = len;
-		sd.flags = flags;
-		sd.u.userptr = base;
-		sd.pos = 0;
-
-		size = __splice_from_pipe(pipe, &sd, pipe_to_user);
-		if (size < 0) {
-			if (!ret)
-				ret = size;
-
-			break;
-		}
-
-		ret += size;
+	ret = rw_copy_check_uvector(READ, uiov, nr_segs,
+				    ARRAY_SIZE(iovstack), iovstack, &iov);
+	if (ret <= 0)
+		return ret;
 
-		if (size < len)
-			break;
+	iov_iter_init(&iter, iov, nr_segs, count, 0);
 
-		nr_segs--;
-		iov++;
-	}
+	sd.len = 0;
+	sd.total_len = count;
+	sd.flags = flags;
+	sd.u.data = &iter;
+	sd.pos = 0;
 
+	pipe_lock(pipe);
+	ret = __splice_from_pipe(pipe, &sd, pipe_to_user);
 	pipe_unlock(pipe);
 
-	if (!ret)
-		ret = error;
+	if (iov != iovstack)
+		kfree(iov);
 
 	return ret;
 }