cifs: add a third receive phase to cifs_demultiplex_thread

Have the demultiplex thread receive just enough to get to the MID, and
then find it before receiving the rest. Later, we'll use this to swap
in a preallocated receive buffer for some calls.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
This commit is contained in:
Jeff Layton 2011-10-19 15:28:57 -04:00
parent 1041e3f991
commit 89482a56a0

View File

@ -746,11 +746,25 @@ cifs_demultiplex_thread(void *p)
if (!is_smb_response(server, buf[0]))
continue;
/* check the length */
if ((pdu_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) ||
(pdu_length < sizeof(struct smb_hdr) - 1 - 4)) {
cERROR(1, "Invalid size SMB length %d pdu_length %d",
4, pdu_length + 4);
/* make sure we have enough to get to the MID */
if (pdu_length < sizeof(struct smb_hdr) - 1 - 4) {
cERROR(1, "SMB response too short (%u bytes)",
pdu_length);
cifs_reconnect(server);
wake_up(&server->response_q);
continue;
}
/* read down to the MID */
length = read_from_socket(server, buf + 4,
sizeof(struct smb_hdr) - 1 - 4);
if (length < 0)
continue;
total_read += length;
if (pdu_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
cERROR(1, "SMB response too long (%u bytes)",
pdu_length);
cifs_reconnect(server);
wake_up(&server->response_q);
continue;
@ -759,12 +773,15 @@ cifs_demultiplex_thread(void *p)
/* else length ok */
if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
isLargeBuf = true;
memcpy(bigbuf, smallbuf, 4);
memcpy(bigbuf, smallbuf, total_read);
smb_buffer = (struct smb_hdr *)bigbuf;
buf = bigbuf;
}
length = read_from_socket(server, buf + 4, pdu_length);
/* now read the rest */
length = read_from_socket(server,
buf + sizeof(struct smb_hdr) - 1,
pdu_length - sizeof(struct smb_hdr) + 1 + 4);
if (length < 0)
continue;
total_read += length;