Author: rmacklem Date: Mon Jun 12 23:41:20 2017 New Revision: 319882 URL: https://svnweb.freebsd.org/changeset/base/319882
Log: Define NFS_MAXXDR as the upper bound on XDR overhead in an NFS RPC. This definition is a part of the maxiotune2 patch that will be committed soon. It is being committed separately to ease merging with the pNFS projects subversion trees. MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D10991 Modified: head/sys/fs/nfs/nfsproto.h Modified: head/sys/fs/nfs/nfsproto.h ============================================================================== --- head/sys/fs/nfs/nfsproto.h Mon Jun 12 22:53:18 2017 (r319881) +++ head/sys/fs/nfs/nfsproto.h Mon Jun 12 23:41:20 2017 (r319882) @@ -56,8 +56,22 @@ #define NFS_MAXDGRAMDATA 16384 #define NFS_MAXPATHLEN 1024 #define NFS_MAXNAMLEN 255 +/* + * Calculating the maximum XDR overhead for an NFS RPC isn't easy. + * NFS_MAXPKTHDR is antiquated and assumes AUTH_SYS over UDP. + * NFS_MAXXDR should be sufficient for all NFS versions over TCP. + * It includes: + * - Maximum RPC message header. It can include 2 400byte authenticators plus + * a machine name of unlimited length, although it is usually relatively + * small. + * - XDR overheads for the NFSv4 compound. This can include Owner and + * Owner_group strings, which are usually fairly small, but are allowed + * to be up to 1024 bytes each. + * 4096 is overkill, but should always be sufficient. + */ #define NFS_MAXPKTHDR 404 -#define NFS_MAXPACKET (NFS_SRVMAXIO + 2048) +#define NFS_MAXXDR 4096 +#define NFS_MAXPACKET (NFS_SRVMAXIO + NFS_MAXXDR) #define NFS_MINPACKET 20 #define NFS_FABLKSIZE 512 /* Size in bytes of a block wrt fa_blocks */ #define NFSV4_MINORVERSION 0 /* V4 Minor version */ _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
