From ddd1ea56367202f6c99135cd59de7a97af4c4ffd Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 27 Aug 2013 21:32:25 -0400 Subject: nfsd4: use xdr_reserve_space in attribute encoding This is a cosmetic change for now; no change in behavior. Note we're just depending on xdr_reserve_space to do the bounds checking for us, we're not really depending on its adjustment of iovec or xdr_buf lengths yet, as those are fixed up by as necessary after the fact by read-link operations and by nfs4svc_encode_compoundres. However we do have to update xdr->iov on read-like operations to prevent xdr_reserve_space from messing with the already-fixed-up length of the the head. When the attribute encoding fails partway through we have to undo the length adjustments made so far. We do it manually for now, but later patches will add an xdr_truncate_encode() helper to handle cases like this. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4idmap.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) (limited to 'fs/nfsd/nfs4idmap.c') diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c index c0dfde68742e..a0ab0a847d69 100644 --- a/fs/nfsd/nfs4idmap.c +++ b/fs/nfsd/nfs4idmap.c @@ -551,44 +551,43 @@ idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen return 0; } -static __be32 encode_ascii_id(u32 id, __be32 **p, int *buflen) +static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id) { char buf[11]; int len; - int bytes; + __be32 *p; len = sprintf(buf, "%u", id); - bytes = 4 + (XDR_QUADLEN(len) << 2); - if (bytes > *buflen) + p = xdr_reserve_space(xdr, len + 4); + if (!p) return nfserr_resource; - *p = xdr_encode_opaque(*p, buf, len); - *buflen -= bytes; + p = xdr_encode_opaque(p, buf, len); return 0; } -static __be32 idmap_id_to_name(struct svc_rqst *rqstp, int type, u32 id, __be32 **p, int *buflen) +static __be32 idmap_id_to_name(struct xdr_stream *xdr, + struct svc_rqst *rqstp, int type, u32 id) { struct ent *item, key = { .id = id, .type = type, }; + __be32 *p; int ret; - int bytes; struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname)); ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item); if (ret == -ENOENT) - return encode_ascii_id(id, p, buflen); + return encode_ascii_id(xdr, id); if (ret) return nfserrno(ret); ret = strlen(item->name); WARN_ON_ONCE(ret > IDMAP_NAMESZ); - bytes = 4 + (XDR_QUADLEN(ret) << 2); - if (bytes > *buflen) + p = xdr_reserve_space(xdr, ret + 4); + if (!p) return nfserr_resource; - *p = xdr_encode_opaque(*p, item->name, ret); - *buflen -= bytes; + p = xdr_encode_opaque(p, item->name, ret); cache_put(&item->h, nn->idtoname_cache); return 0; } @@ -622,11 +621,12 @@ do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u return idmap_name_to_id(rqstp, type, name, namelen, id); } -static __be32 encode_name_from_id(struct svc_rqst *rqstp, int type, u32 id, __be32 **p, int *buflen) +static __be32 encode_name_from_id(struct xdr_stream *xdr, + struct svc_rqst *rqstp, int type, u32 id) { if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS) - return encode_ascii_id(id, p, buflen); - return idmap_id_to_name(rqstp, type, id, p, buflen); + return encode_ascii_id(xdr, id); + return idmap_id_to_name(xdr, rqstp, type, id); } __be32 @@ -655,14 +655,16 @@ nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen, return status; } -__be32 nfsd4_encode_user(struct svc_rqst *rqstp, kuid_t uid, __be32 **p, int *buflen) +__be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp, + kuid_t uid) { u32 id = from_kuid(&init_user_ns, uid); - return encode_name_from_id(rqstp, IDMAP_TYPE_USER, id, p, buflen); + return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id); } -__be32 nfsd4_encode_group(struct svc_rqst *rqstp, kgid_t gid, __be32 **p, int *buflen) +__be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp, + kgid_t gid) { u32 id = from_kgid(&init_user_ns, gid); - return encode_name_from_id(rqstp, IDMAP_TYPE_GROUP, id, p, buflen); + return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id); } -- cgit v1.2.1