cachefiles: avoid deprecated get_seconds()

get_seconds() returns an unsigned long can overflow on some architectures
and is deprecated because of that. In cachefs, we cast that number to
a a 32-bit integer, which will overflow in year 2106 on all architectures.

As confirmed by David Howells, the overflow probably isn't harmful
in the end, since the timestamps are only used to make the file names
unique, but they don't strictly have to be in monotonically increasing
order since the files only exist in order to be deleted as quickly
as possible.

Moving to ktime_get_real_seconds() avoids the deprecated interface.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 5ab411d4bc592ee7eebd46fa6f40265c4f626f13..1645fcfd9691c33bb58114546c262911edfdf25c 100644 (file)
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -338,7 +338,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
 try_again:
        /* first step is to make up a grave dentry in the graveyard */
        sprintf(nbuffer, "%08x%08x",
-               (uint32_t) get_seconds(),
+               (uint32_t) ktime_get_real_seconds(),
                (uint32_t) atomic_inc_return(&cache->gravecounter));
 
        /* do the multiway lock magic */