[PATCH v1 16/42] NFSD: Update the SETATTR3args decoder to use struct xdr_stream

Chuck Lever
2021-01-05T15:31:25Z

fs/nfsd/nfs3xdr.c | 138 +++++++++++++++++++++++++++++++++++++++------
include/uapi/linux/nfs3.h | 6 ++
2 files changed, 127 insertions(+), 17 deletions(-)

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index ba5ec9cdafa1..ef536fb00728 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -39,12 +39,18 @@ encode_time3(__be32 *p, struct timespec64 *time)
return p;
}

-static __be32 *
-decode_time3(__be32 *p, struct timespec64 *time)
+static bool
+svcxdr_decode_nfstime3(struct xdr_stream *xdr, struct timespec64 *timep)
{
- time->tv_sec = ntohl(*p++);
- time->tv_nsec = ntohl(*p++);
- return p;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, XDR_UNIT * 2);
+ if (!p)
+ return false;
+ timep->tv_sec = be32_to_cpup(p++);
+ timep->tv_nsec = be32_to_cpup(p);
+
+ return true;
}

static bool
@@ -150,6 +156,112 @@ svcxdr_decode_diropargs3(struct xdr_stream *xdr, struct svc_fh *fhp,
svcxdr_decode_filename3(xdr, name, len);
}

+static bool
+svcxdr_decode_sattr3(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+ struct iattr *iap)
+{
+ u32 set_it;
+
+ iap->ia_valid = 0;
+
+ if (xdr_stream_decode_bool(xdr, &set_it) < 0)
+ return false;
+ if (set_it) {
+ u32 mode;
+
+ if (xdr_stream_decode_u32(xdr, &mode) < 0)
+ return false;
+ iap->ia_valid |= ATTR_MODE;
+ iap->ia_mode = mode;
+ }
+ if (xdr_stream_decode_bool(xdr, &set_it) < 0)
+ return false;
+ if (set_it) {
+ u32 uid;
+
+ if (xdr_stream_decode_u32(xdr, &uid) < 0)
+ return false;
+ iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), uid);
+ if (uid_valid(iap->ia_uid))
+ iap->ia_valid |= ATTR_UID;
+ }
+ if (xdr_stream_decode_bool(xdr, &set_it) < 0)
+ return false;
+ if (set_it) {
+ u32 gid;
+
+ if (xdr_stream_decode_u32(xdr, &gid) < 0)
+ return false;
+ iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), gid);
+ if (gid_valid(iap->ia_gid))
+ iap->ia_valid |= ATTR_GID;
+ }
+ if (xdr_stream_decode_bool(xdr, &set_it) < 0)
+ return false;
+ if (set_it) {
+ u64 newsize;
+
+ if (xdr_stream_decode_u64(xdr, &newsize) < 0)
+ return false;
+ iap->ia_valid |= ATTR_SIZE;
+ iap->ia_size = min_t(u64, newsize, NFS_OFFSET_MAX);
+ }
+ if (xdr_stream_decode_u32(xdr, &set_it) < 0)
+ return false;
+ switch (set_it) {
+ case DONT_CHANGE:
+ break;
+ case SET_TO_SERVER_TIME:
+ iap->ia_valid |= ATTR_ATIME;
+ break;
+ case SET_TO_CLIENT_TIME:
+ if (!svcxdr_decode_nfstime3(xdr, &iap->ia_atime))
+ return false;
+ iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
+ break;
+ default:
+ return false;
+ }
+ if (xdr_stream_decode_u32(xdr, &set_it) < 0)
+ return false;
+ switch (set_it) {
+ case DONT_CHANGE:
+ break;
+ case SET_TO_SERVER_TIME:
+ iap->ia_valid |= ATTR_MTIME;
+ break;
+ case SET_TO_CLIENT_TIME:
+ if (!svcxdr_decode_nfstime3(xdr, &iap->ia_mtime))
+ return false;
+ iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
+ break;
+ default:
+ return false;
+ }
+
+ return true;
+}
+
+static bool
+svcxdr_decode_sattrguard3(struct xdr_stream *xdr, struct nfsd3_sattrargs *args)
+{
+ __be32 *p;
+ u32 check;
+
+ if (xdr_stream_decode_bool(xdr, &check) < 0)
+ return false;
+ if (check) {
+ p = xdr_inline_decode(xdr, XDR_UNIT * 2);
+ if (!p)
+ return false;
+ args->check_guard = 1;
+ args->guardtime = be32_to_cpup(p);
+ } else
+ args->check_guard = 0;
+
+ return true;
+}
+
static __be32 *
decode_sattr3(__be32 *p, struct iattr *iap, struct user_namespace *userns)
{
@@ -377,20 +489,12 @@ nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, __be32 *p)
int
nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
{
+ struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct nfsd3_sattrargs *args = rqstp->rq_argp;

- p = decode_fh(p, &args->fh);
- if (!p)
- return 0;
- p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
-
- if ((args->check_guard = ntohl(*p++)) != 0) {
- struct timespec64 time;
- p = decode_time3(p, &time);
- args->guardtime = time.tv_sec;
- }
-
- return xdr_argsize_check(rqstp, p);
+ return svcxdr_decode_nfs_fh3(xdr, &args->fh) &&
+ svcxdr_decode_sattr3(rqstp, xdr, &args->attrs) &&
+ svcxdr_decode_sattrguard3(xdr, args);
}

int
diff --git a/include/uapi/linux/nfs3.h b/include/uapi/linux/nfs3.h
index 37e4b34e6b43..c22ab77713bd 100644
--- a/include/uapi/linux/nfs3.h
+++ b/include/uapi/linux/nfs3.h
@@ -63,6 +63,12 @@ enum nfs3_ftype {
NF3BAD = 8
};

+enum nfs3_time_how {
+ DONT_CHANGE = 0,
+ SET_TO_SERVER_TIME = 1,
+ SET_TO_CLIENT_TIME = 2,
+};
+
struct nfs3_fh {
unsigned short size;
unsigned char data[NFS3_FHSIZE];