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![Chuck Lever](/assets/img/avatar_default.png)
Move common code in NFSD's legacy SYMLINK decoders into a helper. The immediate benefits include: - one fewer data copies on transports that support DDP - consistent error checking across all versions - reduction of code duplication - support for both legal forms of SYMLINK requests on RDMA transports for all versions of NFS (in particular, NFSv2, for completeness) In the long term, this helper is an appropriate spot to perform a per-transport call-out to fill the pathname argument using, say, RDMA Reads. Filling the pathname in the proc function also means that eventually the incoming filehandle can be interpreted so that filesystem- specific memory can be allocated as a sink for the pathname argument, rather than using anonymous pages. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
569 lines
13 KiB
C
569 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* XDR support for nfsd
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*
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* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
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*/
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#include "vfs.h"
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#include "xdr.h"
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#include "auth.h"
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#define NFSDDBG_FACILITY NFSDDBG_XDR
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/*
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* Mapping of S_IF* types to NFS file types
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*/
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static u32 nfs_ftypes[] = {
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NFNON, NFCHR, NFCHR, NFBAD,
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NFDIR, NFBAD, NFBLK, NFBAD,
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NFREG, NFBAD, NFLNK, NFBAD,
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NFSOCK, NFBAD, NFLNK, NFBAD,
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};
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/*
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* XDR functions for basic NFS types
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*/
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static __be32 *
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decode_fh(__be32 *p, struct svc_fh *fhp)
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{
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fh_init(fhp, NFS_FHSIZE);
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memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
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fhp->fh_handle.fh_size = NFS_FHSIZE;
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/* FIXME: Look up export pointer here and verify
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* Sun Secure RPC if requested */
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return p + (NFS_FHSIZE >> 2);
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}
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/* Helper function for NFSv2 ACL code */
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__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
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{
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return decode_fh(p, fhp);
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}
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static __be32 *
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encode_fh(__be32 *p, struct svc_fh *fhp)
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{
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memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
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return p + (NFS_FHSIZE>> 2);
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}
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/*
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* Decode a file name and make sure that the path contains
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* no slashes or null bytes.
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*/
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static __be32 *
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decode_filename(__be32 *p, char **namp, unsigned int *lenp)
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{
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char *name;
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unsigned int i;
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if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
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for (i = 0, name = *namp; i < *lenp; i++, name++) {
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if (*name == '\0' || *name == '/')
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return NULL;
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}
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}
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return p;
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}
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static __be32 *
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decode_sattr(__be32 *p, struct iattr *iap)
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{
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u32 tmp, tmp1;
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iap->ia_valid = 0;
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/* Sun client bug compatibility check: some sun clients seem to
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* put 0xffff in the mode field when they mean 0xffffffff.
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* Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
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*/
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if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
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iap->ia_valid |= ATTR_MODE;
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iap->ia_mode = tmp;
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}
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if ((tmp = ntohl(*p++)) != (u32)-1) {
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iap->ia_uid = make_kuid(&init_user_ns, tmp);
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if (uid_valid(iap->ia_uid))
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iap->ia_valid |= ATTR_UID;
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}
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if ((tmp = ntohl(*p++)) != (u32)-1) {
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iap->ia_gid = make_kgid(&init_user_ns, tmp);
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if (gid_valid(iap->ia_gid))
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iap->ia_valid |= ATTR_GID;
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}
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if ((tmp = ntohl(*p++)) != (u32)-1) {
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iap->ia_valid |= ATTR_SIZE;
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iap->ia_size = tmp;
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}
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tmp = ntohl(*p++); tmp1 = ntohl(*p++);
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if (tmp != (u32)-1 && tmp1 != (u32)-1) {
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iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
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iap->ia_atime.tv_sec = tmp;
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iap->ia_atime.tv_nsec = tmp1 * 1000;
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}
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tmp = ntohl(*p++); tmp1 = ntohl(*p++);
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if (tmp != (u32)-1 && tmp1 != (u32)-1) {
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iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
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iap->ia_mtime.tv_sec = tmp;
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iap->ia_mtime.tv_nsec = tmp1 * 1000;
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/*
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* Passing the invalid value useconds=1000000 for mtime
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* is a Sun convention for "set both mtime and atime to
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* current server time". It's needed to make permissions
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* checks for the "touch" program across v2 mounts to
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* Solaris and Irix boxes work correctly. See description of
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* sattr in section 6.1 of "NFS Illustrated" by
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* Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
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*/
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if (tmp1 == 1000000)
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iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
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}
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return p;
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}
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static __be32 *
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encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
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struct kstat *stat)
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{
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struct dentry *dentry = fhp->fh_dentry;
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int type;
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struct timespec time;
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u32 f;
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type = (stat->mode & S_IFMT);
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*p++ = htonl(nfs_ftypes[type >> 12]);
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*p++ = htonl((u32) stat->mode);
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*p++ = htonl((u32) stat->nlink);
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*p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
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*p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
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if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
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*p++ = htonl(NFS_MAXPATHLEN);
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} else {
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*p++ = htonl((u32) stat->size);
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}
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*p++ = htonl((u32) stat->blksize);
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if (S_ISCHR(type) || S_ISBLK(type))
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*p++ = htonl(new_encode_dev(stat->rdev));
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else
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*p++ = htonl(0xffffffff);
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*p++ = htonl((u32) stat->blocks);
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switch (fsid_source(fhp)) {
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default:
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case FSIDSOURCE_DEV:
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*p++ = htonl(new_encode_dev(stat->dev));
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break;
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case FSIDSOURCE_FSID:
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*p++ = htonl((u32) fhp->fh_export->ex_fsid);
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break;
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case FSIDSOURCE_UUID:
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f = ((u32*)fhp->fh_export->ex_uuid)[0];
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f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
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f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
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f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
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*p++ = htonl(f);
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break;
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}
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*p++ = htonl((u32) stat->ino);
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*p++ = htonl((u32) stat->atime.tv_sec);
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*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
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time = stat->mtime;
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lease_get_mtime(d_inode(dentry), &time);
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*p++ = htonl((u32) time.tv_sec);
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*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
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*p++ = htonl((u32) stat->ctime.tv_sec);
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*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
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return p;
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}
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/* Helper function for NFSv2 ACL code */
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__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat)
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{
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return encode_fattr(rqstp, p, fhp, stat);
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}
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/*
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* XDR decode functions
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*/
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int
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nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p)
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{
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_fhandle *args = rqstp->rq_argp;
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p = decode_fh(p, &args->fh);
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if (!p)
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return 0;
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_sattrargs *args = rqstp->rq_argp;
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p = decode_fh(p, &args->fh);
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if (!p)
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return 0;
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p = decode_sattr(p, &args->attrs);
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_diropargs *args = rqstp->rq_argp;
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if (!(p = decode_fh(p, &args->fh))
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|| !(p = decode_filename(p, &args->name, &args->len)))
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return 0;
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_readargs *args = rqstp->rq_argp;
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unsigned int len;
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int v;
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p = decode_fh(p, &args->fh);
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if (!p)
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return 0;
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args->offset = ntohl(*p++);
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len = args->count = ntohl(*p++);
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p++; /* totalcount - unused */
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len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
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/* set up somewhere to store response.
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* We take pages, put them on reslist and include in iovec
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*/
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v=0;
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while (len > 0) {
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struct page *p = *(rqstp->rq_next_page++);
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rqstp->rq_vec[v].iov_base = page_address(p);
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rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
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len -= rqstp->rq_vec[v].iov_len;
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v++;
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}
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args->vlen = v;
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_writeargs *args = rqstp->rq_argp;
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unsigned int len, hdr, dlen;
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struct kvec *head = rqstp->rq_arg.head;
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p = decode_fh(p, &args->fh);
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if (!p)
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return 0;
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p++; /* beginoffset */
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args->offset = ntohl(*p++); /* offset */
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p++; /* totalcount */
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len = args->len = ntohl(*p++);
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/*
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* The protocol specifies a maximum of 8192 bytes.
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*/
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if (len > NFSSVC_MAXBLKSIZE_V2)
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return 0;
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/*
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* Check to make sure that we got the right number of
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* bytes.
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*/
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hdr = (void*)p - head->iov_base;
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if (hdr > head->iov_len)
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return 0;
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dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
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/*
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* Round the length of the data which was specified up to
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* the next multiple of XDR units and then compare that
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* against the length which was actually received.
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* Note that when RPCSEC/GSS (for example) is used, the
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* data buffer can be padded so dlen might be larger
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* than required. It must never be smaller.
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*/
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if (dlen < XDR_QUADLEN(len)*4)
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return 0;
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args->first.iov_base = (void *)p;
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args->first.iov_len = head->iov_len - hdr;
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return 1;
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}
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int
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nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_createargs *args = rqstp->rq_argp;
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if ( !(p = decode_fh(p, &args->fh))
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|| !(p = decode_filename(p, &args->name, &args->len)))
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return 0;
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p = decode_sattr(p, &args->attrs);
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_renameargs *args = rqstp->rq_argp;
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if (!(p = decode_fh(p, &args->ffh))
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|| !(p = decode_filename(p, &args->fname, &args->flen))
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|| !(p = decode_fh(p, &args->tfh))
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|| !(p = decode_filename(p, &args->tname, &args->tlen)))
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return 0;
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_readlinkargs *args = rqstp->rq_argp;
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p = decode_fh(p, &args->fh);
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if (!p)
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return 0;
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args->buffer = page_address(*(rqstp->rq_next_page++));
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_linkargs *args = rqstp->rq_argp;
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if (!(p = decode_fh(p, &args->ffh))
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|| !(p = decode_fh(p, &args->tfh))
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|| !(p = decode_filename(p, &args->tname, &args->tlen)))
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return 0;
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return xdr_argsize_check(rqstp, p);
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}
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int
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nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_symlinkargs *args = rqstp->rq_argp;
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char *base = (char *)p;
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size_t xdrlen;
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if ( !(p = decode_fh(p, &args->ffh))
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|| !(p = decode_filename(p, &args->fname, &args->flen)))
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return 0;
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args->tlen = ntohl(*p++);
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if (args->tlen == 0)
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return 0;
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args->first.iov_base = p;
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args->first.iov_len = rqstp->rq_arg.head[0].iov_len;
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args->first.iov_len -= (char *)p - base;
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/* This request is never larger than a page. Therefore,
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* transport will deliver either:
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* 1. pathname in the pagelist -> sattr is in the tail.
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* 2. everything in the head buffer -> sattr is in the head.
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*/
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if (rqstp->rq_arg.page_len) {
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if (args->tlen != rqstp->rq_arg.page_len)
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return 0;
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p = rqstp->rq_arg.tail[0].iov_base;
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} else {
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xdrlen = XDR_QUADLEN(args->tlen);
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if (xdrlen > args->first.iov_len - (8 * sizeof(__be32)))
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return 0;
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p += xdrlen;
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}
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decode_sattr(p, &args->attrs);
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return 1;
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}
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int
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nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_readdirargs *args = rqstp->rq_argp;
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p = decode_fh(p, &args->fh);
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if (!p)
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return 0;
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args->cookie = ntohl(*p++);
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args->count = ntohl(*p++);
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args->count = min_t(u32, args->count, PAGE_SIZE);
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args->buffer = page_address(*(rqstp->rq_next_page++));
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return xdr_argsize_check(rqstp, p);
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}
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/*
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* XDR encode functions
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*/
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int
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nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p)
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{
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return xdr_ressize_check(rqstp, p);
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}
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int
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nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_attrstat *resp = rqstp->rq_resp;
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p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
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return xdr_ressize_check(rqstp, p);
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}
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int
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nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_diropres *resp = rqstp->rq_resp;
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p = encode_fh(p, &resp->fh);
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p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
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return xdr_ressize_check(rqstp, p);
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}
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int
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nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
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{
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struct nfsd_readlinkres *resp = rqstp->rq_resp;
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*p++ = htonl(resp->len);
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xdr_ressize_check(rqstp, p);
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rqstp->rq_res.page_len = resp->len;
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if (resp->len & 3) {
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/* need to pad the tail */
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rqstp->rq_res.tail[0].iov_base = p;
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*p = 0;
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rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
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}
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
|
|
{
|
|
struct nfsd_readres *resp = rqstp->rq_resp;
|
|
|
|
p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
|
|
*p++ = htonl(resp->count);
|
|
xdr_ressize_check(rqstp, p);
|
|
|
|
/* now update rqstp->rq_res to reflect data as well */
|
|
rqstp->rq_res.page_len = resp->count;
|
|
if (resp->count & 3) {
|
|
/* need to pad the tail */
|
|
rqstp->rq_res.tail[0].iov_base = p;
|
|
*p = 0;
|
|
rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
|
|
{
|
|
struct nfsd_readdirres *resp = rqstp->rq_resp;
|
|
|
|
xdr_ressize_check(rqstp, p);
|
|
p = resp->buffer;
|
|
*p++ = 0; /* no more entries */
|
|
*p++ = htonl((resp->common.err == nfserr_eof));
|
|
rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
|
|
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p)
|
|
{
|
|
struct nfsd_statfsres *resp = rqstp->rq_resp;
|
|
struct kstatfs *stat = &resp->stats;
|
|
|
|
*p++ = htonl(NFSSVC_MAXBLKSIZE_V2); /* max transfer size */
|
|
*p++ = htonl(stat->f_bsize);
|
|
*p++ = htonl(stat->f_blocks);
|
|
*p++ = htonl(stat->f_bfree);
|
|
*p++ = htonl(stat->f_bavail);
|
|
return xdr_ressize_check(rqstp, p);
|
|
}
|
|
|
|
int
|
|
nfssvc_encode_entry(void *ccdv, const char *name,
|
|
int namlen, loff_t offset, u64 ino, unsigned int d_type)
|
|
{
|
|
struct readdir_cd *ccd = ccdv;
|
|
struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
|
|
__be32 *p = cd->buffer;
|
|
int buflen, slen;
|
|
|
|
/*
|
|
dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
|
|
namlen, name, offset, ino);
|
|
*/
|
|
|
|
if (offset > ~((u32) 0)) {
|
|
cd->common.err = nfserr_fbig;
|
|
return -EINVAL;
|
|
}
|
|
if (cd->offset)
|
|
*cd->offset = htonl(offset);
|
|
|
|
/* truncate filename */
|
|
namlen = min(namlen, NFS2_MAXNAMLEN);
|
|
slen = XDR_QUADLEN(namlen);
|
|
|
|
if ((buflen = cd->buflen - slen - 4) < 0) {
|
|
cd->common.err = nfserr_toosmall;
|
|
return -EINVAL;
|
|
}
|
|
if (ino > ~((u32) 0)) {
|
|
cd->common.err = nfserr_fbig;
|
|
return -EINVAL;
|
|
}
|
|
*p++ = xdr_one; /* mark entry present */
|
|
*p++ = htonl((u32) ino); /* file id */
|
|
p = xdr_encode_array(p, name, namlen);/* name length & name */
|
|
cd->offset = p; /* remember pointer */
|
|
*p++ = htonl(~0U); /* offset of next entry */
|
|
|
|
cd->buflen = buflen;
|
|
cd->buffer = p;
|
|
cd->common.err = nfs_ok;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* XDR release functions
|
|
*/
|
|
void
|
|
nfssvc_release_fhandle(struct svc_rqst *rqstp)
|
|
{
|
|
struct nfsd_fhandle *resp = rqstp->rq_resp;
|
|
|
|
fh_put(&resp->fh);
|
|
}
|