Re: [RFC PATCH 05/09] Change RDMA send to regonize page offset in the 1st page

[Tom Talpey]

On 5/17/2018 5:22 PM, Long Li wrote:

From: Long Li <lon...@microsoft.com>

There's a typo "recognize" in the patch title

When doing RDMA send, the offset needs to be checked as data may start in an 
offset
in the 1st page.

Doesn't this patch alter the generic smb2pdu.c code too? I think this
should note "any" send, not just RDMA?

Tom.

Signed-off-by: Long Li <lon...@microsoft.com>
---
  fs/cifs/smb2pdu.c   |  3 ++-
  fs/cifs/smbdirect.c | 25 +++++++++++++++++++------
  2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 5097f28..fdcf97e 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3015,7 +3015,8 @@ smb2_async_writev(struct cifs_writedata *wdata,

rqst.rq_iov = iov;

        rqst.rq_nvec = 2;
-       rqst.rq_pages = wdata->pages;
+       rqst.rq_pages = wdata->direct_pages ? wdata->direct_pages : 
wdata->pages;
+       rqst.rq_offset = wdata->page_offset;
        rqst.rq_npages = wdata->nr_pages;
        rqst.rq_pagesz = wdata->pagesz;
        rqst.rq_tailsz = wdata->tailsz;
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index b0a1955..b46586d 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -2084,8 +2084,10 @@ int smbd_send(struct smbd_connection *info, struct 
smb_rqst *rqst)

/* add in the page array if there is one */

        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) >

@@ -2182,8 +2184,19 @@ 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 = 0;
+               if (i == 0)
+                       offset = rqst->rq_offset;
+               if (rqst->rq_npages == 1 || i == rqst->rq_npages-1)
+                       buflen = rqst->rq_tailsz;
+               else {
+                       /* We have at least two pages, and this is not the last 
page */
+                       if (i == 0)
+                               buflen = rqst->rq_pagesz - rqst->rq_offset;
+                       else
+                               buflen = rqst->rq_pagesz;
+               }
+
                nvecs = (buflen + max_iov_size - 1) / max_iov_size;
                log_write(INFO, "sending pages buflen=%d nvecs=%d\n",
                        buflen, nvecs);
@@ -2194,9 +2207,9 @@ 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;