[PATCH] ubifs: tnc: use monotonic znode timestamp

From: Arnd Bergmann
Date: Wed Jun 20 2018 - 05:21:44 EST


The tnc uses get_seconds() based timestamps to check the age of a znode,
which has two problems: on 32-bit architectures this may overflow in
2038 or 2106, and it gives incorrect information when the system time
is updated using settimeofday().

Using montonic timestamps with ktime_get_seconds() solves both thes
problems.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
fs/ubifs/shrinker.c | 2 +-
fs/ubifs/tnc.c | 4 ++--
fs/ubifs/tnc_misc.c | 2 +-
fs/ubifs/ubifs.h | 2 +-
4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
index 9a9fb94a41c6..9d10cbdec2cc 100644
--- a/fs/ubifs/shrinker.c
+++ b/fs/ubifs/shrinker.c
@@ -71,7 +71,7 @@ static int shrink_tnc(struct ubifs_info *c, int nr, int age, int *contention)
{
int total_freed = 0;
struct ubifs_znode *znode, *zprev;
- int time = get_seconds();
+ time64_t time = ktime_get_seconds();

ubifs_assert(mutex_is_locked(&c->umount_mutex));
ubifs_assert(mutex_is_locked(&c->tnc_mutex));
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 4a21e7f75e7a..6c497fb48b98 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -1179,7 +1179,7 @@ int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
{
int err, exact;
struct ubifs_znode *znode;
- unsigned long time = get_seconds();
+ time64_t time = ktime_get_seconds();

dbg_tnck(key, "search key ");
ubifs_assert(key_type(c, key) < UBIFS_INVALID_KEY);
@@ -1315,7 +1315,7 @@ static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key,
{
int err, exact;
struct ubifs_znode *znode;
- unsigned long time = get_seconds();
+ time64_t time = ktime_get_seconds();

dbg_tnck(key, "search and dirty key ");

diff --git a/fs/ubifs/tnc_misc.c b/fs/ubifs/tnc_misc.c
index 93f5b7859e6f..49f647bc88f0 100644
--- a/fs/ubifs/tnc_misc.c
+++ b/fs/ubifs/tnc_misc.c
@@ -435,7 +435,7 @@ struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c,

zbr->znode = znode;
znode->parent = parent;
- znode->time = get_seconds();
+ znode->time = ktime_get_seconds();
znode->iip = iip;

return znode;
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 04bf84d71e7b..54fb6b1cd042 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -758,7 +758,7 @@ struct ubifs_znode {
struct ubifs_znode *parent;
struct ubifs_znode *cnext;
unsigned long flags;
- unsigned long time;
+ time64_t time;
int level;
int child_cnt;
int iip;
--
2.9.0