From 26978b8b4d83c46f4310b253db70fa9e65149e7c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 10 Mar 2014 14:08:45 -0400 Subject: [PATCH] give ->direct_IO() a copy of iov_iter the thing is, we want to advance what's given to ->direct_IO() as we are forming the request; however, the callers care about the amount of data actually transferred, not the amount we tried to transfer. It's more convenient to allow ->direct_IO() instances do use iov_iter_advance() on the copy of iov_iter, leaving the actual advancing of the original to caller. Signed-off-by: Al Viro --- mm/filemap.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 70c048ea36e0..866f4ae8223b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1699,8 +1699,10 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, size = i_size_read(inode); retval = filemap_write_and_wait_range(mapping, pos, pos + count - 1); - if (!retval) - retval = mapping->a_ops->direct_IO(READ, iocb, &i, pos); + if (!retval) { + struct iov_iter data = i; + retval = mapping->a_ops->direct_IO(READ, iocb, &data, pos); + } if (retval > 0) { *ppos = pos + retval; @@ -2351,6 +2353,7 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, ssize_t written; size_t write_len; pgoff_t end; + struct iov_iter data; if (count != ocount) from->nr_segs = iov_shorten((struct iovec *)from->iov, from->nr_segs, count); @@ -2382,7 +2385,8 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, } } - written = mapping->a_ops->direct_IO(WRITE, iocb, from, pos); + data = *from; + written = mapping->a_ops->direct_IO(WRITE, iocb, &data, pos); /* * Finally, try again to invalidate clean pages which might have been -- 2.30.2