smbd_recv(): switch to _copy_to_iter()
Just fold smbd_recv_buf() into it, and make it use _copy_to_iter() instead
of copying to buffer. That makes the sucker work for any data-destination
iov_iter except ITER_IOVEC (which we never pass to it anyway), single-segment
or not (note that cifs_discard_from_socket() used to barf on cifs-over-rdma
connections) and gets rid of quite a bit of code (entire special-casing
ITER_BVEC part, that switch from hell, etc.).
Making it work for ITER_IOVEC would be also easy (just revert on possible
short copies), but that's really pointless - we never use it that way.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index 433a868..c000cb1 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -1751,11 +1751,13 @@ struct smbd_connection *smbd_get_connection(
}
/*
- * Receive data from receive reassembly queue
+ * Receive data from transport
+ * msg: a msghdr point to the buffer, should not be ITER_IOVEC.
+ * return: total bytes read, or -E... on error. SMB Direct will not do partial
+ * read.
+ *
+ * Receives data from receive reassembly queue
* All the incoming data packets are placed in reassembly queue
- * buf: the buffer to read data into
- * size: the length of data to read
- * return value: actual data read
* Note: this implementation copies the data from reassebmly queue to receive
* buffers used by upper layer. This is not the optimal code path. A better way
* to do it is to not have upper layer allocate its receive buffers but rather
@@ -1763,10 +1765,11 @@ struct smbd_connection *smbd_get_connection(
* consumed. But this will require more changes to upper layer code, and also
* need to consider packet boundaries while they still being reassembled.
*/
-static int smbd_recv_buf(struct smbd_connection *info, char *buf,
- unsigned int size)
+int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
{
+ struct iov_iter *to = &msg->msg_iter;
int to_copy, to_read, data_read, offset;
+ unsigned size = iov_iter_count(to);
int queue_removed = 0;
int queue_length;
int rc;
@@ -1807,7 +1810,7 @@ static int smbd_recv_buf(struct smbd_connection *info, char *buf,
data_read = 0;
to_read = size;
offset = info->first_entry_offset;
- while (data_read < size) {
+ while (iov_iter_count(to)) {
struct smbd_response *response;
struct smbd_data_transfer *data_transfer;
u32 data_length, remaining_data_length, data_offset;
@@ -1828,20 +1831,18 @@ static int smbd_recv_buf(struct smbd_connection *info, char *buf,
* transport layer is added
*/
if (response->first_segment && size == 4) {
- unsigned int rfc1002_len =
- data_length + remaining_data_length;
- *((__be32 *)buf) = cpu_to_be32(rfc1002_len);
+ __be32 rfc1002_len =
+ cpu_to_be32(data_length + remaining_data_length);
+ _copy_to_iter(&rfc1002_len, 4, to);
response->first_segment = false;
log_read(INFO, "returning rfc1002 length %d\n",
- rfc1002_len);
+ be32_to_cpu(rfc1002_len));
return 4;
}
to_copy = min_t(int, data_length - offset, to_read);
- memcpy(
- buf + data_read,
- (char *)data_transfer + data_offset + offset,
- to_copy);
+ _copy_to_iter((char *)data_transfer + data_offset + offset,
+ to_copy, to);
/* move on to the next buffer? */
if (to_copy == data_length - offset) {
@@ -1888,89 +1889,6 @@ static int smbd_recv_buf(struct smbd_connection *info, char *buf,
}
/*
- * Receive a page from receive reassembly queue
- * page: the page to read data into
- * to_read: the length of data to read
- * return value: actual data read
- */
-static int smbd_recv_page(struct smbd_connection *info,
- struct page *page, unsigned int page_offset,
- unsigned int to_read)
-{
- int ret;
- char *to_address;
- void *page_address;
-
- /* make sure we have the page ready for read */
- ret = wait_event_interruptible(
- info->wait_reassembly_queue,
- info->reassembly_data_length >= to_read ||
- info->transport_status != SMBD_CONNECTED);
- if (ret)
- return ret;
-
- /* now we can read from reassembly queue and not sleep */
- page_address = kmap_atomic(page);
- to_address = (char *) page_address + page_offset;
-
- log_read(INFO, "reading from page=%p address=%p to_read=%d\n",
- page, to_address, to_read);
-
- ret = smbd_recv_buf(info, to_address, to_read);
- kunmap_atomic(page_address);
-
- return ret;
-}
-
-/*
- * Receive data from transport
- * msg: a msghdr point to the buffer, can be ITER_KVEC or ITER_BVEC
- * return: total bytes read, or 0. SMB Direct will not do partial read.
- */
-int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
-{
- char *buf;
- struct page *page;
- unsigned int to_read, page_offset;
- int rc;
-
- if (iov_iter_rw(&msg->msg_iter) == WRITE) {
- /* It's a bug in upper layer to get there */
- cifs_dbg(VFS, "Invalid msg iter dir %u\n",
- iov_iter_rw(&msg->msg_iter));
- rc = -EINVAL;
- goto out;
- }
-
- switch (iov_iter_type(&msg->msg_iter)) {
- case ITER_KVEC:
- buf = msg->msg_iter.kvec->iov_base;
- to_read = msg->msg_iter.kvec->iov_len;
- rc = smbd_recv_buf(info, buf, to_read);
- break;
-
- case ITER_BVEC:
- page = msg->msg_iter.bvec->bv_page;
- page_offset = msg->msg_iter.bvec->bv_offset;
- to_read = msg->msg_iter.bvec->bv_len;
- rc = smbd_recv_page(info, page, page_offset, to_read);
- break;
-
- default:
- /* It's a bug in upper layer to get there */
- cifs_dbg(VFS, "Invalid msg type %d\n",
- iov_iter_type(&msg->msg_iter));
- rc = -EINVAL;
- }
-
-out:
- /* SMBDirect will read it all or nothing */
- if (rc > 0)
- msg->msg_iter.count = 0;
- return rc;
-}
-
-/*
* Send data to transport
* Each rqst is transported as a SMBDirect payload
* rqst: the data to write
