libceph: use timespec64 in for keepalive2 and ticket validity

ceph_con_keepalive_expired() is the last user of timespec_add() and some
of the last uses of ktime_get_real_ts().  Replacing this with timespec64
based interfaces  lets us remove that deprecated API.

I'm introducing new ceph_encode_timespec64()/ceph_decode_timespec64()
here that take timespec64 structures and convert to/from ceph_timespec,
which is defined to have an unsigned 32-bit tv_sec member. This extends
the range of valid times to year 2106, avoiding the year 2038 overflow.

The ceph file system portion still uses the old functions for inode
timestamps, this will be done separately after the VFS layer is converted.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

2 files changed, 20 insertions, 2 deletions

diff --git a/include/linux/ceph/decode.h b/include/linux/ceph/decode.h
index d143ac8879c6..094b9b4a34f3 100644
--- a/include/linux/ceph/decode.h
+++ b/include/linux/ceph/decode.h
@@ -194,8 +194,26 @@ ceph_decode_skip_n(p, end, sizeof(u8), bad)
         } while (0)
 
 /*
- * struct ceph_timespec <-> struct timespec
+ * struct ceph_timespec <-> struct timespec64
  */
+static inline void ceph_decode_timespec64(struct timespec64 *ts,
+                                          const struct ceph_timespec *tv)
+{
+        /*
+         * This will still overflow in year 2106.  We could extend
+         * the protocol to steal two more bits from tv_nsec to
+         * add three more 136 year epochs after that the way ext4
+         * does if necessary.
+         */
+        ts->tv_sec = (time64_t)le32_to_cpu(tv->tv_sec);
+        ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec);
+}
+static inline void ceph_encode_timespec64(struct ceph_timespec *tv,
+                                          const struct timespec64 *ts)
+{
+        tv->tv_sec = cpu_to_le32((u32)ts->tv_sec);
+        tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec);
+}
 static inline void ceph_decode_timespec(struct timespec *ts,
                                         const struct ceph_timespec *tv)
 {
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index c7dfcb8a1fb2..a718b877c597 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -330,7 +330,7 @@ struct ceph_connection {
         int in_base_pos;     /* bytes read */
         __le64 in_temp_ack;  /* for reading an ack */
 
-        struct timespec last_keepalive_ack; /* keepalive2 ack stamp */
+        struct timespec64 last_keepalive_ack; /* keepalive2 ack stamp */
 
         struct delayed_work work;           /* send|recv work */
         unsigned long       delay;          /* current delay interval */