[PATCH 2/2] nfs: update inode ctime after removexattr operation

[Jeff Layton <jlayton@kernel.org>]

xfstest generic/728 fails with delegated timestamps. The client does a
removexattr and then a stat to test the ctime, which doesn't change. The
stat() doesn't trigger a GETATTR because of the delegated timestamps, so
it relies on the cached ctime, which is wrong.

The setxattr compound has a trailing GETATTR, which ensures that its
ctime gets updated. Follow the same strategy with removexattr.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfs/nfs42proc.c      | 18 ++++++++++++++++--
 fs/nfs/nfs42xdr.c       | 10 ++++++++--
 include/linux/nfs_xdr.h |  3 +++
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 7b3ca68fb4bb3bee293f8621e5ed5fa596f5da3f..7e5c1172fc11c9d5a55b3621977ac83bb98f7c20 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -1372,11 +1372,15 @@ int nfs42_proc_clone(struct file *src_f, struct file *dst_f,
 static int _nfs42_proc_removexattr(struct inode *inode, const char *name)
 {
 	struct nfs_server *server = NFS_SERVER(inode);
+	__u32 bitmask[NFS_BITMASK_SZ];
 	struct nfs42_removexattrargs args = {
 		.fh = NFS_FH(inode),
+		.bitmask = bitmask,
 		.xattr_name = name,
 	};
-	struct nfs42_removexattrres res;
+	struct nfs42_removexattrres res = {
+		.server = server,
+	};
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVEXATTR],
 		.rpc_argp = &args,
@@ -1385,12 +1389,22 @@ static int _nfs42_proc_removexattr(struct inode *inode, const char *name)
 	int ret;
 	unsigned long timestamp = jiffies;
 
+	res.fattr = nfs_alloc_fattr();
+	if (!res.fattr)
+		return -ENOMEM;
+
+	nfs4_bitmask_set(bitmask, server->cache_consistency_bitmask,
+			 inode, NFS_INO_INVALID_CHANGE);
+
 	ret = nfs4_call_sync(server->client, server, &msg, &args.seq_args,
 	    &res.seq_res, 1);
 	trace_nfs4_removexattr(inode, name, ret);
-	if (!ret)
+	if (!ret) {
 		nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);
+		ret = nfs_post_op_update_inode(inode, res.fattr);
+	}
 
+	kfree(res.fattr);
 	return ret;
 }
 
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 5c7452ce6e8ac94bd24bc3a33d4479d458a29907..ec105c62f721cfe01bfc60f5981396958084d627 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -263,11 +263,13 @@
 #define NFS4_enc_removexattr_sz		(compound_encode_hdr_maxsz + \
 					 encode_sequence_maxsz + \
 					 encode_putfh_maxsz + \
-					 encode_removexattr_maxsz)
+					 encode_removexattr_maxsz + \
+					 encode_getattr_maxsz)
 #define NFS4_dec_removexattr_sz		(compound_decode_hdr_maxsz + \
 					 decode_sequence_maxsz + \
 					 decode_putfh_maxsz + \
-					 decode_removexattr_maxsz)
+					 decode_removexattr_maxsz + \
+					 decode_getattr_maxsz)
 
 /*
  * These values specify the maximum amount of data that is not
@@ -869,6 +871,7 @@ static void nfs4_xdr_enc_removexattr(struct rpc_rqst *req,
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, args->fh, &hdr);
 	encode_removexattr(xdr, args->xattr_name, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
 	encode_nops(&hdr);
 }
 
@@ -1818,6 +1821,9 @@ static int nfs4_xdr_dec_removexattr(struct rpc_rqst *req,
 		goto out;
 
 	status = decode_removexattr(xdr, &res->cinfo);
+	if (status)
+		goto out;
+	status = decode_getfattr(xdr, res->fattr, res->server);
 out:
 	return status;
 }
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index ff1f12aa73d27b6fd874baf7019dd03195fc36e5..fcbd21b5685f46136a210c8e11c20a54d6ed9dad 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1611,12 +1611,15 @@ struct nfs42_listxattrsres {
 struct nfs42_removexattrargs {
 	struct nfs4_sequence_args	seq_args;
 	struct nfs_fh			*fh;
+	const u32			*bitmask;
 	const char			*xattr_name;
 };
 
 struct nfs42_removexattrres {
 	struct nfs4_sequence_res	seq_res;
 	struct nfs4_change_info		cinfo;
+	struct nfs_fattr		*fattr;
+	const struct nfs_server		*server;
 };
 
 #endif /* CONFIG_NFS_V4_2 */

-- 
2.53.0