From 5ecda13711b3bd4a750b5740897bf13d1720de7c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 13 Apr 2017 14:13:36 -0400 Subject: generic_file_read_iter(): make use of iov_iter_revert() Signed-off-by: Al Viro --- mm/filemap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'mm/filemap.c') diff --git a/mm/filemap.c b/mm/filemap.c index 9f788eecd2c5..cc480c07c71b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2033,7 +2033,6 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) if (iocb->ki_flags & IOCB_DIRECT) { struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; - struct iov_iter data = *iter; loff_t size; size = i_size_read(inode); @@ -2044,11 +2043,12 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) file_accessed(file); - retval = mapping->a_ops->direct_IO(iocb, &data); + retval = mapping->a_ops->direct_IO(iocb, iter); if (retval >= 0) { iocb->ki_pos += retval; - iov_iter_advance(iter, retval); + count -= retval; } + iov_iter_revert(iter, iov_iter_count(iter) - count); /* * Btrfs can have a short DIO read if we encounter @@ -2059,7 +2059,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) * the rest of the read. Buffered reads will not work for * DAX files, so don't bother trying. */ - if (retval < 0 || !iov_iter_count(iter) || iocb->ki_pos >= size || + if (retval < 0 || !count || iocb->ki_pos >= size || IS_DAX(inode)) goto out; } -- cgit v1.2.3-55-g7522