From: Andy Adamson <andros@xxxxxxxxxx>
NFSv4 needs to restart deferred processing at the operation which caused the
deferral.
Add a callback and a defer_data pointer in svc_rqst to enable svc_defer to
save partial result state in the deferral request.
Add page pointer storage and resused fields to svc_deferred_req to store
the pointers to the partially processed request.
Add callbacks and a defer_data pointer in svc_deferred_request to enable
svc_deferred_recv to restore and release the partial result state.
The rq_save_state callback sets the deferral request restore_state callback and
defer_data.
The svc_deferred_req defer_data and result pages survive multiple deferral
processing caveat resetting in the save and restore callbacks.
Signed-off-by: Andy Adamson<andros@xxxxxxxxxx>
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
include/linux/sunrpc/svc.h | 10 ++++++++++
net/sunrpc/svc_xprt.c | 19 +++++++++++++++----
2 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 7653dd3..d86111f 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -227,6 +227,9 @@ struct svc_rqst {
struct svc_cred rq_cred; /* auth info */
void * rq_xprt_ctxt; /* transport specific context ptr */
struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */
+ /* callback to save deferred request state */
+ void (*rq_save_state)(struct svc_rqst *, struct svc_deferred_req *);
+ void *rq_defer_data; /* defer state data to save */
size_t rq_xprt_hlen; /* xprt header len */
struct xdr_buf rq_arg;
@@ -335,6 +338,13 @@ struct svc_deferred_req {
union svc_addr_u daddr; /* where reply must come from */
struct cache_deferred_req handle;
size_t xprt_hlen;
+ /* callbacks to restore and release deferred request state
+ * set in rq_save_state */
+ void (*restore_state)(struct svc_rqst *, struct svc_deferred_req *);
+ void (*release_state)(struct svc_deferred_req *);
+ void *defer_data; /* defer state data */
+ struct page *respages[RPCSVC_MAXPAGES];
+ short resused;
int argslen;
__be32 args[0];
};
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index bf5b5cd..bf12475 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -903,6 +903,8 @@ static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
struct svc_xprt *xprt = dr->xprt;
if (too_many) {
+ if (dr->release_state)
+ dr->release_state(dr);
svc_xprt_put(xprt);
kfree(dr);
return;
@@ -941,10 +943,9 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req)
size_t size;
/* FIXME maybe discard if size too large */
size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
- dr = kmalloc(size, GFP_KERNEL);
+ dr = kzalloc(size, GFP_KERNEL);
if (dr == NULL)
- return NULL;
-
+ goto out;
dr->handle.owner = rqstp->rq_server;
dr->prot = rqstp->rq_prot;
memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
@@ -958,6 +959,15 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req)
memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
dr->argslen << 2);
}
+ if (rqstp->rq_save_state)
+ rqstp->rq_save_state(rqstp, dr);
+out:
+ /* reset for each deferral */
+ rqstp->rq_defer_data = NULL;
+ rqstp->rq_save_state = NULL;
+ if (dr == NULL)
+ return NULL;
+
svc_xprt_get(rqstp->rq_xprt);
dr->xprt = rqstp->rq_xprt;
@@ -986,10 +996,11 @@ static int svc_deferred_recv(struct svc_rqst *rqstp)
rqstp->rq_xprt_hlen = dr->xprt_hlen;
rqstp->rq_daddr = dr->daddr;
rqstp->rq_respages = rqstp->rq_pages;
+ if (dr->restore_state)
+ dr->restore_state(rqstp, dr);
return (dr->argslen<<2) - dr->xprt_hlen;
}
-
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
{
struct svc_deferred_req *dr = NULL;
--
1.6.0.2
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