At 05:00 PM 10/15/2008, andros@xxxxxxxxxx wrote:
>From: Andy Adamson <andros@xxxxxxxxxx>
>
>For EOS, NFSD compound RPC deferred processing should restart 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 to svc_deferred_req to cache the pages holding 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.
>
>Signed-off-by: Andy Adamson<andros@xxxxxxxxx>
>---
> include/linux/sunrpc/svc.h | 10 ++++++++++
> net/sunrpc/svc_xprt.c | 20 +++++++++++++++-----
> 2 files changed, 25 insertions(+), 5 deletions(-)
>
>diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
>index dc69068..46a4097 100644
>--- a/include/linux/sunrpc/svc.h
>+++ b/include/linux/sunrpc/svc.h
>@@ -215,6 +215,9 @@ 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;
>@@ -323,6 +326,13 @@ 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];
Is it worthwhile to make this a dynamically allocated pointer? If the max
pages size is large (1MB means 256), it's quite a large array for something
that may rarely be so full.
>+ short resused;
I find "resused" to be a little bit confusing. It looks a lot like "reused" and
in any case seems to be a pagecount. Maybe, respagecount?
> int argslen;
> __be32 args[0];
> };
>diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
>index e46c825..531b325 100644
>--- a/net/sunrpc/svc_xprt.c
>+++ b/net/sunrpc/svc_xprt.c
>@@ -876,6 +876,8 @@ 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;
>@@ -902,10 +904,10 @@ static void svc_revisit(struct
>cache_deferred_req *dreq, int too_many)
> static struct cache_deferred_req *svc_defer(struct cache_req *req)
> {
> struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
>- struct svc_deferred_req *dr;
>+ struct svc_deferred_req *dr = NULL;
>
> if (rqstp->rq_arg.page_len)
>- return NULL; /* if more than a page, give up FIXME */
>+ goto out; /* if more than a page, give up FIXME */
> if (rqstp->rq_deferred) {
> dr = rqstp->rq_deferred;
> rqstp->rq_deferred = NULL;
>@@ -914,9 +916,9 @@ 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);
Does the entire buffer need to be zeroed? Again, if the rq_arg.len is large,
this may be a needless overhead.
Tom.
> if (dr == NULL)
>- return NULL;
>+ goto out;
>
> dr->handle.owner = rqstp->rq_server;
> dr->prot = rqstp->rq_prot;
>@@ -935,7 +937,13 @@ static struct cache_deferred_req
>*svc_defer(struct cache_req *req)
> dr->xprt = rqstp->rq_xprt;
>
> dr->handle.revisit = svc_revisit;
>- return &dr->handle;
>+ if (rqstp->rq_save_state)
>+ rqstp->rq_save_state(rqstp, dr);
>+out:
>+ rqstp->rq_defer_data = NULL;
>+ rqstp->rq_save_state = NULL;
>+
>+ return dr ? &dr->handle: NULL;
> }
>
> /*
>@@ -959,6 +967,8 @@ 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;
> }
>
>--
>1.5.4.3
>
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