Currently, all three chunk list encoders each use a portion of the
one rl_segments array in rpcrdma_req. This is because the MWs for
each chunk list were preserved in rl_segments so that ro_unmap could
find and invalidate them after the RPC was complete.
However, now that MWs are placed on a per-req linked list as they
are registered, there is no longer any information in rpcrdma_mr_seg
that is shared between ro_map and ro_unmap_{sync,safe}, and thus
nothing in rl_segments needs to be preserved after
rpcrdma_marshal_req is complete.
Thus the rl_segments array can be used now just for the needs of
each rpcrdma_convert_iovs call. Once each chunk list is encoded, the
next chunk list encoder is free to re-use all of rl_segments.
This means all three chunk lists in one RPC request can now each
encode a full size data payload with no increase in the size of
rl_segments.
This is a key requirement for Kerberos support, since both the Call
and Reply for a single RPC transaction are conveyed via Long
messages (RDMA Read/Write). Both can be large.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/rpc_rdma.c | 61 ++++++++++++++++++---------------------
net/sunrpc/xprtrdma/xprt_rdma.h | 36 ++++++++++-------------
2 files changed, 44 insertions(+), 53 deletions(-)
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 6d34c1f..f60d229 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -196,8 +196,7 @@ rpcrdma_tail_pullup(struct xdr_buf *buf)
* MR when they can.
*/
static int
-rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg,
- int n, int nsegs)
+rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg, int n)
{
size_t page_offset;
u32 remaining;
@@ -206,7 +205,7 @@ rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg,
base = vec->iov_base;
page_offset = offset_in_page(base);
remaining = vec->iov_len;
- while (remaining && n < nsegs) {
+ while (remaining && n < RPCRDMA_MAX_SEGS) {
seg[n].mr_page = NULL;
seg[n].mr_offset = base;
seg[n].mr_len = min_t(u32, PAGE_SIZE - page_offset, remaining);
@@ -230,23 +229,23 @@ rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg,
static int
rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
- enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs)
+ enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg)
{
- int len, n = 0, p;
- int page_base;
+ int len, n, p, page_base;
struct page **ppages;
+ n = 0;
if (pos == 0) {
- n = rpcrdma_convert_kvec(&xdrbuf->head[0], seg, n, nsegs);
- if (n == nsegs)
- return -EIO;
+ n = rpcrdma_convert_kvec(&xdrbuf->head[0], seg, n);
+ if (n == RPCRDMA_MAX_SEGS)
+ goto out_overflow;
}
len = xdrbuf->page_len;
ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT);
page_base = xdrbuf->page_base & ~PAGE_MASK;
p = 0;
- while (len && n < nsegs) {
+ while (len && n < RPCRDMA_MAX_SEGS) {
if (!ppages[p]) {
/* alloc the pagelist for receiving buffer */
ppages[p] = alloc_page(GFP_ATOMIC);
@@ -257,7 +256,7 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
seg[n].mr_offset = (void *)(unsigned long) page_base;
seg[n].mr_len = min_t(u32, PAGE_SIZE - page_base, len);
if (seg[n].mr_len > PAGE_SIZE)
- return -EIO;
+ goto out_overflow;
len -= seg[n].mr_len;
++n;
++p;
@@ -265,8 +264,8 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
}
/* Message overflows the seg array */
- if (len && n == nsegs)
- return -EIO;
+ if (len && n == RPCRDMA_MAX_SEGS)
+ goto out_overflow;
/* When encoding the read list, the tail is always sent inline */
if (type == rpcrdma_readch)
@@ -277,12 +276,16 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
* xdr pad bytes, saving the server an RDMA operation. */
if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize)
return n;
- n = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, n, nsegs);
- if (n == nsegs)
- return -EIO;
+ n = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, n);
+ if (n == RPCRDMA_MAX_SEGS)
+ goto out_overflow;
}
return n;
+
+out_overflow:
+ pr_err("rpcrdma: segment array overflow\n");
+ return -EIO;
}
static inline __be32 *
@@ -310,7 +313,7 @@ rpcrdma_encode_read_list(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_req *req, struct rpc_rqst *rqst,
__be32 *iptr, enum rpcrdma_chunktype rtype)
{
- struct rpcrdma_mr_seg *seg = req->rl_nextseg;
+ struct rpcrdma_mr_seg *seg;
struct rpcrdma_mw *mw;
unsigned int pos;
int n, nsegs;
@@ -323,8 +326,8 @@ rpcrdma_encode_read_list(struct rpcrdma_xprt *r_xprt,
pos = rqst->rq_snd_buf.head[0].iov_len;
if (rtype == rpcrdma_areadch)
pos = 0;
- nsegs = rpcrdma_convert_iovs(&rqst->rq_snd_buf, pos, rtype, seg,
- RPCRDMA_MAX_SEGS - req->rl_nchunks);
+ seg = req->rl_segments;
+ nsegs = rpcrdma_convert_iovs(&rqst->rq_snd_buf, pos, rtype, seg);
if (nsegs < 0)
return ERR_PTR(nsegs);
@@ -349,11 +352,9 @@ rpcrdma_encode_read_list(struct rpcrdma_xprt *r_xprt,
mw->mw_handle, n < nsegs ? "more" : "last");
r_xprt->rx_stats.read_chunk_count++;
- req->rl_nchunks++;
seg += n;
nsegs -= n;
} while (nsegs);
- req->rl_nextseg = seg;
/* Finish Read list */
*iptr++ = xdr_zero; /* Next item not present */
@@ -377,7 +378,7 @@ rpcrdma_encode_write_list(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
struct rpc_rqst *rqst, __be32 *iptr,
enum rpcrdma_chunktype wtype)
{
- struct rpcrdma_mr_seg *seg = req->rl_nextseg;
+ struct rpcrdma_mr_seg *seg;
struct rpcrdma_mw *mw;
int n, nsegs, nchunks;
__be32 *segcount;
@@ -387,10 +388,10 @@ rpcrdma_encode_write_list(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
return iptr;
}
+ seg = req->rl_segments;
nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf,
rqst->rq_rcv_buf.head[0].iov_len,
- wtype, seg,
- RPCRDMA_MAX_SEGS - req->rl_nchunks);
+ wtype, seg);
if (nsegs < 0)
return ERR_PTR(nsegs);
@@ -414,12 +415,10 @@ rpcrdma_encode_write_list(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
r_xprt->rx_stats.write_chunk_count++;
r_xprt->rx_stats.total_rdma_request += seg->mr_len;
- req->rl_nchunks++;
nchunks++;
seg += n;
nsegs -= n;
} while (nsegs);
- req->rl_nextseg = seg;
/* Update count of segments in this Write chunk */
*segcount = cpu_to_be32(nchunks);
@@ -446,7 +445,7 @@ rpcrdma_encode_reply_chunk(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_req *req, struct rpc_rqst *rqst,
__be32 *iptr, enum rpcrdma_chunktype wtype)
{
- struct rpcrdma_mr_seg *seg = req->rl_nextseg;
+ struct rpcrdma_mr_seg *seg;
struct rpcrdma_mw *mw;
int n, nsegs, nchunks;
__be32 *segcount;
@@ -456,8 +455,8 @@ rpcrdma_encode_reply_chunk(struct rpcrdma_xprt *r_xprt,
return iptr;
}
- nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf, 0, wtype, seg,
- RPCRDMA_MAX_SEGS - req->rl_nchunks);
+ seg = req->rl_segments;
+ nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf, 0, wtype, seg);
if (nsegs < 0)
return ERR_PTR(nsegs);
@@ -481,12 +480,10 @@ rpcrdma_encode_reply_chunk(struct rpcrdma_xprt *r_xprt,
r_xprt->rx_stats.reply_chunk_count++;
r_xprt->rx_stats.total_rdma_request += seg->mr_len;
- req->rl_nchunks++;
nchunks++;
seg += n;
nsegs -= n;
} while (nsegs);
- req->rl_nextseg = seg;
/* Update count of segments in the Reply chunk */
*segcount = cpu_to_be32(nchunks);
@@ -656,8 +653,6 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
* send a Call message with a Position Zero Read chunk and a
* regular Read chunk at the same time.
*/
- req->rl_nchunks = 0;
- req->rl_nextseg = req->rl_segments;
iptr = headerp->rm_body.rm_chunks;
iptr = rpcrdma_encode_read_list(r_xprt, req, rqst, iptr, rtype);
if (IS_ERR(iptr))
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 025365c..c713483 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -171,23 +171,14 @@ rdmab_to_msg(struct rpcrdma_regbuf *rb)
* o recv buffer (posted to provider)
* o ib_sge (also donated to provider)
* o status of reply (length, success or not)
- * o bookkeeping state to get run by tasklet (list, etc)
+ * o bookkeeping state to get run by reply handler (list, etc)
*
- * These are allocated during initialization, per-transport instance;
- * however, the tasklet execution list itself is global, as it should
- * always be pretty short.
+ * These are allocated during initialization, per-transport instance.
*
* N of these are associated with a transport instance, and stored in
* struct rpcrdma_buffer. N is the max number of outstanding requests.
*/
-#define RPCRDMA_MAX_DATA_SEGS ((1 * 1024 * 1024) / PAGE_SIZE)
-
-/* data segments + head/tail for Call + head/tail for Reply */
-#define RPCRDMA_MAX_SEGS (RPCRDMA_MAX_DATA_SEGS + 4)
-
-struct rpcrdma_buffer;
-
struct rpcrdma_rep {
struct ib_cqe rr_cqe;
unsigned int rr_len;
@@ -267,13 +258,18 @@ struct rpcrdma_mw {
* of iovs for send operations. The reason is that the iovs passed to
* ib_post_{send,recv} must not be modified until the work request
* completes.
- *
- * NOTES:
- * o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
- * marshal. The number needed varies depending on the iov lists that
- * are passed to us and the memory registration mode we are in.
*/
+/* Maximum number of page-sized "segments" per chunk list to be
+ * registered or invalidated. Must handle a Reply chunk:
+ */
+enum {
+ RPCRDMA_MAX_IOV_SEGS = 3,
+ RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
+ RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS +
+ RPCRDMA_MAX_IOV_SEGS,
+};
+
struct rpcrdma_mr_seg { /* chunk descriptors */
u32 mr_len; /* length of chunk or segment */
struct page *mr_page; /* owning page, if any */
@@ -282,10 +278,10 @@ struct rpcrdma_mr_seg { /* chunk descriptors */
#define RPCRDMA_MAX_IOVS (2)
+struct rpcrdma_buffer;
struct rpcrdma_req {
struct list_head rl_free;
unsigned int rl_niovs;
- unsigned int rl_nchunks;
unsigned int rl_connect_cookie;
struct rpc_task *rl_task;
struct rpcrdma_buffer *rl_buffer;
@@ -293,13 +289,13 @@ struct rpcrdma_req {
struct ib_sge rl_send_iov[RPCRDMA_MAX_IOVS];
struct rpcrdma_regbuf *rl_rdmabuf;
struct rpcrdma_regbuf *rl_sendbuf;
- struct list_head rl_registered; /* registered segments */
- struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
- struct rpcrdma_mr_seg *rl_nextseg;
struct ib_cqe rl_cqe;
struct list_head rl_all;
bool rl_backchannel;
+
+ struct list_head rl_registered; /* registered segments */
+ struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
};
static inline struct rpcrdma_req *
--
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