CIFS: SMBD: Support page offset in RDMA send

The RDMA send function needs to look at offset in the request pages, and
send data starting from there.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index c62f7c9..6141e3c 100644 (file)
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -17,6 +17,7 @@
 #include <linux/highmem.h>
 #include "smbdirect.h"
 #include "cifs_debug.h"
+#include "cifsproto.h"
 
 static struct smbd_response *get_empty_queue_buffer(
                struct smbd_connection *info);
@@ -2082,7 +2083,7 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
        struct kvec vec;
        int nvecs;
        int size;
-       int buflen = 0, remaining_data_length;
+       unsigned int buflen = 0, remaining_data_length;
        int start, i, j;
        int max_iov_size =
                info->max_send_size - sizeof(struct smbd_data_transfer);
@@ -2113,10 +2114,17 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
                buflen += iov[i].iov_len;
        }
 
-       /* add in the page array if there is one */
+       /*
+        * Add in the page array if there is one. The caller needs to set
+        * rq_tailsz to PAGE_SIZE when the buffer has multiple pages and
+        * ends at page boundary
+        */
        if (rqst->rq_npages) {
-               buflen += rqst->rq_pagesz * (rqst->rq_npages - 1);
-               buflen += rqst->rq_tailsz;
+               if (rqst->rq_npages == 1)
+                       buflen += rqst->rq_tailsz;
+               else
+                       buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
+                                       rqst->rq_offset + rqst->rq_tailsz;
        }
 
        if (buflen + sizeof(struct smbd_data_transfer) >
@@ -2213,8 +2221,9 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
 
        /* now sending pages if there are any */
        for (i = 0; i < rqst->rq_npages; i++) {
-               buflen = (i == rqst->rq_npages-1) ?
-                       rqst->rq_tailsz : rqst->rq_pagesz;
+               unsigned int offset;
+
+               rqst_page_get_length(rqst, i, &buflen, &offset);
                nvecs = (buflen + max_iov_size - 1) / max_iov_size;
                log_write(INFO, "sending pages buflen=%d nvecs=%d\n",
                        buflen, nvecs);
@@ -2225,9 +2234,11 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
                        remaining_data_length -= size;
                        log_write(INFO, "sending pages i=%d offset=%d size=%d"
                                " remaining_data_length=%d\n",
-                               i, j*max_iov_size, size, remaining_data_length);
+                               i, j*max_iov_size+offset, size,
+                               remaining_data_length);
                        rc = smbd_post_send_page(
-                               info, rqst->rq_pages[i], j*max_iov_size,
+                               info, rqst->rq_pages[i],
+                               j*max_iov_size + offset,
                                size, remaining_data_length);
                        if (rc)
                                goto done;