Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull read/write updates from Al Viro:
 "Christoph's fs/read_write.c series - consolidation and cleanups"

* 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  nfsd: remove nfsd_vfs_read
  nfsd: use vfs_iter_read/write
  fs: implement vfs_iter_write using do_iter_write
  fs: implement vfs_iter_read using do_iter_read
  fs: move more code into do_iter_read/do_iter_write
  fs: remove __do_readv_writev
  fs: remove do_compat_readv_writev
  fs: remove do_readv_writev

1 files changed, 91 insertions, 129 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index d591eeed061f..a2cbc8303dae 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -356,46 +356,6 @@ out_putf:
 }
 #endif
 
-ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
-{
-	struct kiocb kiocb;
-	ssize_t ret;
-
-	if (!file->f_op->read_iter)
-		return -EINVAL;
-
-	init_sync_kiocb(&kiocb, file);
-	kiocb.ki_pos = *ppos;
-
-	iter->type |= READ;
-	ret = call_read_iter(file, &kiocb, iter);
-	BUG_ON(ret == -EIOCBQUEUED);
-	if (ret > 0)
-		*ppos = kiocb.ki_pos;
-	return ret;
-}
-EXPORT_SYMBOL(vfs_iter_read);
-
-ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
-{
-	struct kiocb kiocb;
-	ssize_t ret;
-
-	if (!file->f_op->write_iter)
-		return -EINVAL;
-
-	init_sync_kiocb(&kiocb, file);
-	kiocb.ki_pos = *ppos;
-
-	iter->type |= WRITE;
-	ret = call_write_iter(file, &kiocb, iter);
-	BUG_ON(ret == -EIOCBQUEUED);
-	if (ret > 0)
-		*ppos = kiocb.ki_pos;
-	return ret;
-}
-EXPORT_SYMBOL(vfs_iter_write);
-
 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
 {
 	struct inode *inode;
@@ -910,86 +870,114 @@ out:
 }
 #endif
 
-static ssize_t __do_readv_writev(int type, struct file *file,
-				 struct iov_iter *iter, loff_t *pos, int flags)
+static ssize_t do_iter_read(struct file *file, struct iov_iter *iter,
+		loff_t *pos, int flags)
 {
 	size_t tot_len;
 	ssize_t ret = 0;
 
+	if (!(file->f_mode & FMODE_READ))
+		return -EBADF;
+	if (!(file->f_mode & FMODE_CAN_READ))
+		return -EINVAL;
+
 	tot_len = iov_iter_count(iter);
 	if (!tot_len)
 		goto out;
-	ret = rw_verify_area(type, file, pos, tot_len);
+	ret = rw_verify_area(READ, file, pos, tot_len);
 	if (ret < 0)
-		goto out;
-
-	if (type != READ)
-		file_start_write(file);
+		return ret;
 
-	if ((type == READ && file->f_op->read_iter) ||
-	    (type == WRITE && file->f_op->write_iter))
-		ret = do_iter_readv_writev(file, iter, pos, type, flags);
+	if (file->f_op->read_iter)
+		ret = do_iter_readv_writev(file, iter, pos, READ, flags);
 	else
-		ret = do_loop_readv_writev(file, iter, pos, type, flags);
-
-	if (type != READ)
-		file_end_write(file);
-
+		ret = do_loop_readv_writev(file, iter, pos, READ, flags);
 out:
-	if ((ret + (type == READ)) > 0) {
-		if (type == READ)
-			fsnotify_access(file);
-		else
-			fsnotify_modify(file);
-	}
+	if (ret >= 0)
+		fsnotify_access(file);
 	return ret;
 }
 
-static ssize_t do_readv_writev(int type, struct file *file,
-			       const struct iovec __user *uvector,
-			       unsigned long nr_segs, loff_t *pos,
-			       int flags)
+ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
+		int flags)
 {
-	struct iovec iovstack[UIO_FASTIOV];
-	struct iovec *iov = iovstack;
-	struct iov_iter iter;
-	ssize_t ret;
+	if (!file->f_op->read_iter)
+		return -EINVAL;
+	return do_iter_read(file, iter, ppos, flags);
+}
+EXPORT_SYMBOL(vfs_iter_read);
+
+static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
+		loff_t *pos, int flags)
+{
+	size_t tot_len;
+	ssize_t ret = 0;
+
+	if (!(file->f_mode & FMODE_WRITE))
+		return -EBADF;
+	if (!(file->f_mode & FMODE_CAN_WRITE))
+		return -EINVAL;
 
-	ret = import_iovec(type, uvector, nr_segs,
-			   ARRAY_SIZE(iovstack), &iov, &iter);
+	tot_len = iov_iter_count(iter);
+	if (!tot_len)
+		return 0;
+	ret = rw_verify_area(WRITE, file, pos, tot_len);
 	if (ret < 0)
 		return ret;
 
-	ret = __do_readv_writev(type, file, &iter, pos, flags);
-	kfree(iov);
-
+	file_start_write(file);
+	if (file->f_op->write_iter)
+		ret = do_iter_readv_writev(file, iter, pos, WRITE, flags);
+	else
+		ret = do_loop_readv_writev(file, iter, pos, WRITE, flags);
+	file_end_write(file);
+	if (ret > 0)
+		fsnotify_modify(file);
 	return ret;
 }
 
+ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
+		int flags)
+{
+	if (!file->f_op->write_iter)
+		return -EINVAL;
+	return do_iter_write(file, iter, ppos, flags);
+}
+EXPORT_SYMBOL(vfs_iter_write);
+
 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
 		  unsigned long vlen, loff_t *pos, int flags)
 {
-	if (!(file->f_mode & FMODE_READ))
-		return -EBADF;
-	if (!(file->f_mode & FMODE_CAN_READ))
-		return -EINVAL;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	ssize_t ret;
 
-	return do_readv_writev(READ, file, vec, vlen, pos, flags);
-}
+	ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
+	if (ret >= 0) {
+		ret = do_iter_read(file, &iter, pos, flags);
+		kfree(iov);
+	}
 
+	return ret;
+}
 EXPORT_SYMBOL(vfs_readv);
 
 ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 		   unsigned long vlen, loff_t *pos, int flags)
 {
-	if (!(file->f_mode & FMODE_WRITE))
-		return -EBADF;
-	if (!(file->f_mode & FMODE_CAN_WRITE))
-		return -EINVAL;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	ssize_t ret;
 
-	return do_readv_writev(WRITE, file, vec, vlen, pos, flags);
+	ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
+	if (ret >= 0) {
+		ret = do_iter_write(file, &iter, pos, flags);
+		kfree(iov);
+	}
+	return ret;
 }
-
 EXPORT_SYMBOL(vfs_writev);
 
 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
@@ -1137,44 +1125,20 @@ SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
 }
 
 #ifdef CONFIG_COMPAT
-
-static ssize_t compat_do_readv_writev(int type, struct file *file,
-			       const struct compat_iovec __user *uvector,
-			       unsigned long nr_segs, loff_t *pos,
-			       int flags)
+static size_t compat_readv(struct file *file,
+			   const struct compat_iovec __user *vec,
+			   unsigned long vlen, loff_t *pos, int flags)
 {
 	struct iovec iovstack[UIO_FASTIOV];
 	struct iovec *iov = iovstack;
 	struct iov_iter iter;
 	ssize_t ret;
 
-	ret = compat_import_iovec(type, uvector, nr_segs,
-				  UIO_FASTIOV, &iov, &iter);
-	if (ret < 0)
-		return ret;
-
-	ret = __do_readv_writev(type, file, &iter, pos, flags);
-	kfree(iov);
-
-	return ret;
-}
-
-static size_t compat_readv(struct file *file,
-			   const struct compat_iovec __user *vec,
-			   unsigned long vlen, loff_t *pos, int flags)
-{
-	ssize_t ret = -EBADF;
-
-	if (!(file->f_mode & FMODE_READ))
-		goto out;
-
-	ret = -EINVAL;
-	if (!(file->f_mode & FMODE_CAN_READ))
-		goto out;
-
-	ret = compat_do_readv_writev(READ, file, vec, vlen, pos, flags);
-
-out:
+	ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
+	if (ret >= 0) {
+		ret = do_iter_read(file, &iter, pos, flags);
+		kfree(iov);
+	}
 	if (ret > 0)
 		add_rchar(current, ret);
 	inc_syscr(current);
@@ -1270,18 +1234,16 @@ static size_t compat_writev(struct file *file,
 			    const struct compat_iovec __user *vec,
 			    unsigned long vlen, loff_t *pos, int flags)
 {
-	ssize_t ret = -EBADF;
-
-	if (!(file->f_mode & FMODE_WRITE))
-		goto out;
-
-	ret = -EINVAL;
-	if (!(file->f_mode & FMODE_CAN_WRITE))
-		goto out;
-
-	ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos, flags);
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	ssize_t ret;
 
-out:
+	ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter);
+	if (ret >= 0) {
+		ret = do_iter_write(file, &iter, pos, flags);
+		kfree(iov);
+	}
 	if (ret > 0)
 		add_wchar(current, ret);
 	inc_syscw(current);