diff options
Diffstat (limited to 'include/linux/sunrpc/svc.h')
| -rw-r--r-- | include/linux/sunrpc/svc.h | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index cb0ed9beb2272..74e52c245da4b 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -13,6 +13,7 @@ #include <linux/in.h> #include <linux/sunrpc/types.h> #include <linux/sunrpc/xdr.h> +#include <linux/sunrpc/auth.h> #include <linux/sunrpc/svcauth.h> #include <linux/wait.h> #include <linux/mm.h> @@ -95,8 +96,28 @@ static inline void svc_get(struct svc_serv *serv) * Maximum payload size supported by a kernel RPC server. * This is use to determine the max number of pages nfsd is * willing to return in a single READ operation. + * + * These happen to all be powers of 2, which is not strictly + * necessary but helps enforce the real limitation, which is + * that they should be multiples of PAGE_CACHE_SIZE. + * + * For UDP transports, a block plus NFS,RPC, and UDP headers + * has to fit into the IP datagram limit of 64K. The largest + * feasible number for all known page sizes is probably 48K, + * but we choose 32K here. This is the same as the historical + * Linux limit; someone who cares more about NFS/UDP performance + * can test a larger number. + * + * For TCP transports we have more freedom. A size of 1MB is + * chosen to match the client limit. Other OSes are known to + * have larger limits, but those numbers are probably beyond + * the point of diminishing returns. */ -#define RPCSVC_MAXPAYLOAD (64*1024u) +#define RPCSVC_MAXPAYLOAD (1*1024*1024u) +#define RPCSVC_MAXPAYLOAD_TCP RPCSVC_MAXPAYLOAD +#define RPCSVC_MAXPAYLOAD_UDP (32*1024u) + +extern u32 svc_max_payload(const struct svc_rqst *rqstp); /* * RPC Requsts and replies are stored in one or more pages. |