[PATCH] md: use seconds granularity for error logging

[Arnd Bergmann]

The md code stores the exact time of the last error in the
last_read_error variable using a timespec structure. It only
ever uses the seconds portion of that though, so we can
use a scalar for it.

There won't be an overflow in 2038 here, because it already
used monotonic time and 32-bit is enough for that, but I've
decided to use time64_t for consistency in the conversion.

Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
 drivers/md/md.c     |  3 +--
 drivers/md/md.h     |  2 +-
 drivers/md/raid10.c | 11 +++++------
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3745b9a7a2d7..ad512ad4610f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3179,8 +3179,7 @@ int md_rdev_init(struct md_rdev *rdev)
        rdev->data_offset = 0;
        rdev->new_data_offset = 0;
        rdev->sb_events = 0;
-       rdev->last_read_error.tv_sec  = 0;
-       rdev->last_read_error.tv_nsec = 0;
+       rdev->last_read_error = 0;
        rdev->sb_loaded = 0;
        rdev->bb_page = NULL;
        atomic_set(&rdev->nr_pending, 0);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 3c3412d85e42..20c667579ede 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -99,7 +99,7 @@ struct md_rdev {
        atomic_t        read_errors;    /* number of consecutive read errors 
that
                                         * we have tried to ignore.
                                         */
-       struct timespec last_read_error;        /* monotonic time since our
+       time64_t        last_read_error;        /* monotonic time since our
                                                 * last read error
                                                 */
        atomic_t        corrected_errors; /* number of corrected read errors,
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 41191e04d565..f8cdd08d0a40 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2170,21 +2170,20 @@ static void recovery_request_write(struct mddev *mddev, 
struct r10bio *r10_bio)
  */
 static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
 {
-       struct timespec cur_time_mon;
+       long cur_time_mon;
        unsigned long hours_since_last;
        unsigned int read_errors = atomic_read(&rdev->read_errors);
 
-       ktime_get_ts(&cur_time_mon);
+       cur_time_mon = ktime_get_seconds();
 
-       if (rdev->last_read_error.tv_sec == 0 &&
-           rdev->last_read_error.tv_nsec == 0) {
+       if (rdev->last_read_error == 0) {
                /* first time we've seen a read error */
                rdev->last_read_error = cur_time_mon;
                return;
        }
 
-       hours_since_last = (cur_time_mon.tv_sec -
-                           rdev->last_read_error.tv_sec) / 3600;
+       hours_since_last = (long)(cur_time_mon -
+                           rdev->last_read_error) / 3600;
 
        rdev->last_read_error = cur_time_mon;
 
-- 
2.9.0