The patch titled
Subject: shmem: use monotonic time for i_generation
has been added to the -mm tree. Its filename is
shmem-use-monotonic-time-for-i_generation.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/shmem-use-monotonic-time-for-i_generation.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/shmem-use-monotonic-time-for-i_generation.patch
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From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: shmem: use monotonic time for i_generation
get_seconds() is deprecated because it will lead to a 32-bit overflow in
2038 or 2106. We don't need the i_generation to be strictly monotonic
anyway, and other file systems like ext4 and xfs just use prandom_u32(),
so let's use the same one here.
If this is considered too slow, we could also use ktime_get_seconds() or
ktime_get_real_seconds() to keep the previous behavior. Both of these
return a time64_t and are not deprecated, but only return a unique value
once per second, and are predictable.
Link: http://lkml.kernel.org/r/20180620082556.581543-1-arnd@xxxxxxxx
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN mm/shmem.c~shmem-use-monotonic-time-for-i_generation mm/shmem.c
--- a/mm/shmem.c~shmem-use-monotonic-time-for-i_generation
+++ a/mm/shmem.c
@@ -29,6 +29,7 @@
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/mm.h>
+#include <linux/random.h>
#include <linux/sched/signal.h>
#include <linux/export.h>
#include <linux/swap.h>
@@ -2187,7 +2188,7 @@ static struct inode *shmem_get_inode(str
inode_init_owner(inode, dir, mode);
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
- inode->i_generation = get_seconds();
+ inode->i_generation = prandom_u32();
info = SHMEM_I(inode);
memset(info, 0, (char *)inode - (char *)info);
spin_lock_init(&info->lock);
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
ocfs2-dlmglue-clean-up-timestamp-handling.patch
shmem-use-monotonic-time-for-i_generation.patch
crash-print-timestamp-using-time64_t.patch
reiserfs-remove-unused-j_timestamp.patch
reiserfs-use-monotonic-time-for-j_trans_start_time.patch
reiserfs-remove-obsolete-print_time-function.patch
fat-propagate-64-bit-inode-timestamps.patch
adfs-use-timespec64-for-time-conversion.patch
sysinfo-remove-get_monotonic_boottime.patch
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