[RFC 08/13] cifs: Add a function to read into an iter from a socket

David Howells
2023-01-25T21:47:35Z

Add a helper function to read data from a socket into the given iterator.

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: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org

Link: https://lore.kernel.org/r/164928617874.457102.10021662143234315566.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165211419563.3154751.18431990381145195050.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165348879662.2106726.16881134187242702351.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165364826398.3334034.12541600783145647319.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/166126395495.708021.12328677373159554478.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/166697258876.61150.3530237818849429372.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/166732031039.3186319.10691316510079412635.stgit@warthog.procyon.org.uk/ # rfc
---
fs/cifs/cifsproto.h | 3 +++
fs/cifs/connect.c | 16 ++++++++++++++++
2 files changed, 19 insertions(+)

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 1207b39686fb..cb7a3fe89278 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -244,6 +244,9 @@ extern int cifs_read_page_from_socket(struct TCP_Server_Info *server,
struct page *page,
unsigned int page_offset,
unsigned int to_read);
+int cifs_read_iter_from_socket(struct TCP_Server_Info *server,
+ struct iov_iter *iter,
+ unsigned int to_read);
extern int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb);
void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx);
int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index b2a04b4e89a5..5bdabbb6c45c 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -765,6 +765,22 @@ cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
return cifs_readv_from_socket(server, &smb_msg);
}

+int
+cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct iov_iter *iter,
+ unsigned int to_read)
+{
+ struct msghdr smb_msg;
+ int ret;
+
+ smb_msg.msg_iter = *iter;
+ if (smb_msg.msg_iter.count > to_read)
+ smb_msg.msg_iter.count = to_read;
+ ret = cifs_readv_from_socket(server, &smb_msg);
+ if (ret > 0)
+ iov_iter_advance(iter, ret);
+ return ret;
+}
+
static bool
is_smb_response(struct TCP_Server_Info *server, unsigned char type)
{