[PATCH v3 19/24] fs: nfs: Make nfs boot time y2038 safe

From: Deepa Dinamani
Date: Sat Jun 25 2016 - 17:38:50 EST


boot_time is represented as a struct timespec.
struct timespec and CURRENT_TIME are not y2038 safe.
Overall, the plan is to use timespec64 and ktime_t for
all internal kernel representation of timestamps.
CURRENT_TIME will also be removed.

boot_time is used to construct the nfs client boot verifier.

Use ktime_t to represent boot_time and ktime_get_real() for
the boot_time value.

Following Trond's request https://lkml.org/lkml/2016/6/9/22 ,
use ktime_t instead of converting to struct timespec64.

Use higher and lower 32 bit parts of ktime_t for the boot
verifier.

Use the lower 32 bit part of ktime_t for the authsys_parms
stamp field.

Signed-off-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: Anna Schumaker <anna.schumaker@xxxxxxxxxx>
Cc: linux-nfs@xxxxxxxxxxxxxxx
---
fs/nfs/client.c | 2 +-
fs/nfs/netns.h | 2 +-
fs/nfs/nfs4proc.c | 10 ++++++----
fs/nfs/nfs4xdr.c | 2 +-
4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 4849d0f..92798bb 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1078,7 +1078,7 @@ void nfs_clients_init(struct net *net)
idr_init(&nn->cb_ident_idr);
#endif
spin_lock_init(&nn->nfs_client_lock);
- nn->boot_time = CURRENT_TIME;
+ nn->boot_time = ktime_get_real();
}

#ifdef CONFIG_PROC_FS
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index f0e06e4..fbce0d8 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -29,7 +29,7 @@ struct nfs_net {
int cb_users[NFS4_MAX_MINOR_VERSION + 1];
#endif
spinlock_t nfs_client_lock;
- struct timespec boot_time;
+ ktime_t boot_time;
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *proc_nfsfs;
#endif
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 406dd3e..8d9b5a9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5062,12 +5062,14 @@ static void nfs4_init_boot_verifier(const struct nfs_client *clp,
if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
/* An impossible timestamp guarantees this value
* will never match a generated boot time. */
- verf[0] = 0;
- verf[1] = cpu_to_be32(NSEC_PER_SEC + 1);
+ verf[0] = cpu_to_be32(U32_MAX);
+ verf[1] = cpu_to_be32(U32_MAX);
} else {
struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
- verf[0] = cpu_to_be32(nn->boot_time.tv_sec);
- verf[1] = cpu_to_be32(nn->boot_time.tv_nsec);
+ u64 ns = ktime_to_ns(nn->boot_time);
+
+ verf[0] = cpu_to_be32(ns >> 32);
+ verf[1] = cpu_to_be32(ns);
}
memcpy(bootverf->data, verf, sizeof(bootverf->data));
}
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 661e753..5944be0 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1850,7 +1850,7 @@ static void encode_create_session(struct xdr_stream *xdr,
*p++ = cpu_to_be32(RPC_AUTH_UNIX); /* auth_sys */

/* authsys_parms rfc1831 */
- *p++ = cpu_to_be32(nn->boot_time.tv_nsec); /* stamp */
+ *p++ = cpu_to_be32(ktime_to_ns(nn->boot_time)); /* stamp */
p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
*p++ = cpu_to_be32(0); /* UID */
*p++ = cpu_to_be32(0); /* GID */
--
1.9.1