[RFC 13/13] cifs: DIO to/from KVEC-type iterators should now work

David Howells
2023-01-25T21:49:47Z

DIO to/from KVEC-type iterators should now work as the iterator is passed
down to the socket in non-RDMA/non-crypto mode and in RDMA or crypto mode
care is taken to handle vmap/vmalloc correctly and not take page refs when
building a scatterlist.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Tom Talpey <tom@talpey.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
---
fs/cifs/file.c | 20 --------------------
1 file changed, 20 deletions(-)

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 89d59723bda8..98d3ad86995d 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3545,16 +3545,6 @@ static ssize_t __cifs_writev(
struct cifs_aio_ctx *ctx;
int rc;

- /*
- * iov_iter_get_pages_alloc doesn't work with ITER_KVEC.
- * In this case, fall back to non-direct write function.
- * this could be improved by getting pages directly in ITER_KVEC
- */
- if (direct && iov_iter_is_kvec(from)) {
- cifs_dbg(FYI, "use non-direct cifs_writev for kvec I/O\n");
- direct = false;
- }
-
rc = generic_write_checks(iocb, from);
if (rc <= 0)
return rc;
@@ -4088,16 +4078,6 @@ static ssize_t __cifs_readv(
loff_t offset = iocb->ki_pos;
struct cifs_aio_ctx *ctx;

- /*
- * iov_iter_get_pages_alloc() doesn't work with ITER_KVEC,
- * fall back to data copy read path
- * this could be improved by getting pages directly in ITER_KVEC
- */
- if (direct && iov_iter_is_kvec(to)) {
- cifs_dbg(FYI, "use non-direct cifs_user_readv for kvec I/O\n");
- direct = false;
- }
-
len = iov_iter_count(to);
if (!len)
return 0;