[PATCH] nfs: Fix fscache volume key rendering for endianness

From: David Howells
Date: Thu May 19 2022 - 03:52:01 EST


Fix fscache volume key rendering for endianness. Convert the BE numbers in
the address to host-endian before printing them so that they're consistent
if the cache is copied between architectures.

Question: This change could lead to misidentification of a volume directory
in the cache on a LE machine (it's unlikely because the port number as well
as the address numbers all get flipped), but it was introduced in -rc1 in
this cycle so probably isn't in any distro kernels yet. Should I add a
version number to enforce non-matching?

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Dave Wysochanski <dwysocha@xxxxxxxxxx>
cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
cc: Anna Schumaker <anna@xxxxxxxxxx>
cc: Jeff Layton <jlayton@xxxxxxxxxx>
cc: linux-nfs@xxxxxxxxxxxxxxx
cc: linux-cachefs@xxxxxxxxxx
---

fs/nfs/fscache.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index f73c09a9cf0a..0e5572b192b2 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -54,17 +54,17 @@ static bool nfs_fscache_get_client_key(struct nfs_client *clp,

switch (clp->cl_addr.ss_family) {
case AF_INET:
- if (!nfs_append_int(key, _len, sin->sin_port) ||
- !nfs_append_int(key, _len, sin->sin_addr.s_addr))
+ if (!nfs_append_int(key, _len, ntohs(sin->sin_port)) ||
+ !nfs_append_int(key, _len, ntohl(sin->sin_addr.s_addr)))
return false;
return true;

case AF_INET6:
- if (!nfs_append_int(key, _len, sin6->sin6_port) ||
- !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[0]) ||
- !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[1]) ||
- !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[2]) ||
- !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[3]))
+ if (!nfs_append_int(key, _len, ntohs(sin6->sin6_port)) ||
+ !nfs_append_int(key, _len, ntohl(sin6->sin6_addr.s6_addr32[0])) ||
+ !nfs_append_int(key, _len, ntohl(sin6->sin6_addr.s6_addr32[1])) ||
+ !nfs_append_int(key, _len, ntohl(sin6->sin6_addr.s6_addr32[2])) ||
+ !nfs_append_int(key, _len, ntohl(sin6->sin6_addr.s6_addr32[3])))
return false;
return true;