[Patch v3 11/16] CIFS: SMBD: Support page offset in memory registration

From: Long Li
Date: Fri Sep 07 2018 - 22:15:41 EST


From: Long Li <longli@xxxxxxxxxxxxx>

Change code to pass the correct page offset during memory registration for
RDMA read/write.

Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
---
fs/cifs/smb2pdu.c | 18 ++++++++++++------
fs/cifs/smbdirect.c | 29 +++++++++++++++++++++--------
fs/cifs/smbdirect.h | 2 +-
3 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index f603fbe..fc30774 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2623,8 +2623,8 @@ smb2_new_read_req(void **buf, unsigned int *total_len,

rdata->mr = smbd_register_mr(
server->smbd_conn, rdata->pages,
- rdata->nr_pages, rdata->tailsz,
- true, need_invalidate);
+ rdata->nr_pages, rdata->page_offset,
+ rdata->tailsz, true, need_invalidate);
if (!rdata->mr)
return -ENOBUFS;

@@ -3013,16 +3013,22 @@ smb2_async_writev(struct cifs_writedata *wdata,

wdata->mr = smbd_register_mr(
server->smbd_conn, wdata->pages,
- wdata->nr_pages, wdata->tailsz,
- false, need_invalidate);
+ wdata->nr_pages, wdata->page_offset,
+ wdata->tailsz, false, need_invalidate);
if (!wdata->mr) {
rc = -ENOBUFS;
goto async_writev_out;
}
req->Length = 0;
req->DataOffset = 0;
- req->RemainingBytes =
- cpu_to_le32((wdata->nr_pages-1)*PAGE_SIZE + wdata->tailsz);
+ if (wdata->nr_pages > 1)
+ req->RemainingBytes =
+ cpu_to_le32(
+ (wdata->nr_pages - 1) * wdata->pagesz -
+ wdata->page_offset + wdata->tailsz
+ );
+ else
+ req->RemainingBytes = cpu_to_le32(wdata->tailsz);
req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE;
if (need_invalidate)
req->Channel = SMB2_CHANNEL_RDMA_V1;
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index b470cd0..f61daa9 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -2475,7 +2475,7 @@ static struct smbd_mr *get_mr(struct smbd_connection *info)
*/
struct smbd_mr *smbd_register_mr(
struct smbd_connection *info, struct page *pages[], int num_pages,
- int tailsz, bool writing, bool need_invalidate)
+ int offset, int tailsz, bool writing, bool need_invalidate)
{
struct smbd_mr *smbdirect_mr;
int rc, i;
@@ -2498,17 +2498,30 @@ struct smbd_mr *smbd_register_mr(
smbdirect_mr->sgl_count = num_pages;
sg_init_table(smbdirect_mr->sgl, num_pages);

- for (i = 0; i < num_pages - 1; i++)
- sg_set_page(&smbdirect_mr->sgl[i], pages[i], PAGE_SIZE, 0);
+ log_rdma_mr(INFO, "num_pages=0x%x offset=0x%x tailsz=0x%x\n",
+ num_pages, offset, tailsz);
+
+ if (num_pages == 1) {
+ sg_set_page(&smbdirect_mr->sgl[0], pages[0], tailsz, offset);
+ goto skip_multiple_pages;
+ }

- sg_set_page(&smbdirect_mr->sgl[i], pages[i],
- tailsz ? tailsz : PAGE_SIZE, 0);
+ /* We have at least two pages to register */
+ sg_set_page(
+ &smbdirect_mr->sgl[0], pages[0], PAGE_SIZE - offset, offset);
+ i = 1;
+ while (i < num_pages - 1) {
+ sg_set_page(&smbdirect_mr->sgl[i], pages[i], PAGE_SIZE, 0);
+ i++;
+ }
+ sg_set_page(&smbdirect_mr->sgl[i], pages[i], tailsz, 0);

+skip_multiple_pages:
dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
smbdirect_mr->dir = dir;
rc = ib_dma_map_sg(info->id->device, smbdirect_mr->sgl, num_pages, dir);
if (!rc) {
- log_rdma_mr(INFO, "ib_dma_map_sg num_pages=%x dir=%x rc=%x\n",
+ log_rdma_mr(ERR, "ib_dma_map_sg num_pages=%x dir=%x rc=%x\n",
num_pages, dir, rc);
goto dma_map_error;
}
@@ -2516,8 +2529,8 @@ struct smbd_mr *smbd_register_mr(
rc = ib_map_mr_sg(smbdirect_mr->mr, smbdirect_mr->sgl, num_pages,
NULL, PAGE_SIZE);
if (rc != num_pages) {
- log_rdma_mr(INFO,
- "ib_map_mr_sg failed rc = %x num_pages = %x\n",
+ log_rdma_mr(ERR,
+ "ib_map_mr_sg failed rc = %d num_pages = %x\n",
rc, num_pages);
goto map_mr_error;
}
diff --git a/fs/cifs/smbdirect.h b/fs/cifs/smbdirect.h
index f9038da..1e419c2 100644
--- a/fs/cifs/smbdirect.h
+++ b/fs/cifs/smbdirect.h
@@ -321,7 +321,7 @@ struct smbd_mr {
/* Interfaces to register and deregister MR for RDMA read/write */
struct smbd_mr *smbd_register_mr(
struct smbd_connection *info, struct page *pages[], int num_pages,
- int tailsz, bool writing, bool need_invalidate);
+ int offset, int tailsz, bool writing, bool need_invalidate);
int smbd_deregister_mr(struct smbd_mr *mr);

#else
--
2.7.4