4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Long Li <longli@xxxxxxxxxxxxx>
commit 8bcda1d2a79da4ab84162574eee2c9f6e1a12a03 upstream.
It's not necessary to allocate another iov when going through the buffers
in smbd_send() through RDMA send.
Remove it to reduce stack size.
Thanks to Matt for spotting a printk typo in the earlier version of this.
CC: Matt Redfearn <matt.redfearn@xxxxxxxx>
Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
Acked-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Steve French <smfrench@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/cifs/smbdirect.c | 36 ++++++++++++------------------------
1 file changed, 12 insertions(+), 24 deletions(-)
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -2086,7 +2086,7 @@ int smbd_send(struct smbd_connection *in
int start, i, j;
int max_iov_size =
info->max_send_size - sizeof(struct smbd_data_transfer);
- struct kvec iov[SMBDIRECT_MAX_SGE];
+ struct kvec *iov;
int rc;
info->smbd_send_pending++;
@@ -2096,32 +2096,20 @@ int smbd_send(struct smbd_connection *in
}
/*
- * This usually means a configuration error
- * We use RDMA read/write for packet size > rdma_readwrite_threshold
- * as long as it's properly configured we should never get into this
- * situation
- */
- if (rqst->rq_nvec + rqst->rq_npages > SMBDIRECT_MAX_SGE) {
- log_write(ERR, "maximum send segment %x exceeding %x\n",
- rqst->rq_nvec + rqst->rq_npages, SMBDIRECT_MAX_SGE);
- rc = -EINVAL;
- goto done;
- }
-
- /*
- * Remove the RFC1002 length defined in MS-SMB2 section 2.1
- * It is used only for TCP transport
+ * Skip the RFC1002 length defined in MS-SMB2 section 2.1
+ * It is used only for TCP transport in the iov[0]
* In future we may want to add a transport layer under protocol
* layer so this will only be issued to TCP transport
*/
- iov[0].iov_base = (char *)rqst->rq_iov[0].iov_base + 4;
- iov[0].iov_len = rqst->rq_iov[0].iov_len - 4;
- buflen += iov[0].iov_len;
+
+ if (rqst->rq_iov[0].iov_len != 4) {
+ log_write(ERR, "expected the pdu length in 1st iov, but got %zu\n", rqst->rq_iov[0].iov_len);
+ return -EINVAL;
+ }
+ iov = &rqst->rq_iov[1];
/* total up iov array first */
- for (i = 1; i < rqst->rq_nvec; i++) {
- iov[i].iov_base = rqst->rq_iov[i].iov_base;
- iov[i].iov_len = rqst->rq_iov[i].iov_len;
+ for (i = 0; i < rqst->rq_nvec-1; i++) {
buflen += iov[i].iov_len;
}
@@ -2194,14 +2182,14 @@ int smbd_send(struct smbd_connection *in
goto done;
}
i++;
- if (i == rqst->rq_nvec)
+ if (i == rqst->rq_nvec-1)
break;
}
start = i;
buflen = 0;
} else {
i++;
- if (i == rqst->rq_nvec) {
+ if (i == rqst->rq_nvec-1) {
/* send out all remaining vecs */
remaining_data_length -= buflen;
log_write(INFO,
