From 46c9a946d766fa830a85d6599de5891fe9e717d2 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 17 Aug 2018 15:45:09 -0700 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@arndb.de Signed-off-by: Arnd Bergmann Reviewed-by: Andrew Morton Cc: Hugh Dickins Cc: Mike Kravetz Cc: "Kirill A. Shutemov" Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/shmem.c b/mm/shmem.c index 06ebe17bb924..c48c79018a7c 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -2188,7 +2189,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode 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); -- cgit v1.2.3