[PATCH 6.1 018/451] nfsd: Fix creation time serialization order

Sasha Levin
2024-03-24T23:12:26Z

From: Tavian Barnes <tavianator@tavianator.com>

In nfsd4_encode_fattr(), TIME_CREATE was being written out after all
other times. However, they should be written out in an order that
matches the bit flags in bmval1, which in this case are

#define FATTR4_WORD1_TIME_ACCESS (1UL << 15)
#define FATTR4_WORD1_TIME_CREATE (1UL << 18)
#define FATTR4_WORD1_TIME_DELTA (1UL << 19)
#define FATTR4_WORD1_TIME_METADATA (1UL << 20)
#define FATTR4_WORD1_TIME_MODIFY (1UL << 21)

so TIME_CREATE should come second.

I noticed this on a FreeBSD NFSv4.2 client, which supports creation
times. On this client, file times were weirdly permuted. With this
patch applied on the server, times looked normal on the client.

Fixes: e377a3e698fb ("nfsd: Add support for the birth time attribute")
Link: https://unix.stackexchange.com/q/749605/56202
Signed-off-by: Tavian Barnes <tavianator@tavianator.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfsd/nfs4xdr.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 514f4456cf5c6..4ed9fef14adc2 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3364,6 +3364,11 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
if (status)
goto out;
}
+ if (bmval1 & FATTR4_WORD1_TIME_CREATE) {
+ status = nfsd4_encode_nfstime4(xdr, &stat.btime);
+ if (status)
+ goto out;
+ }
if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
p = xdr_reserve_space(xdr, 12);
if (!p)
@@ -3380,11 +3385,6 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
if (status)
goto out;
}
- if (bmval1 & FATTR4_WORD1_TIME_CREATE) {
- status = nfsd4_encode_nfstime4(xdr, &stat.btime);
- if (status)
- goto out;
- }
if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
u64 ino = stat.ino;

--
2.43.0