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| author | Arnd Bergmann <arnd@arndb.de> | 2018-08-17 15:45:09 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-17 16:20:28 -0700 |
| commit | 46c9a946d766fa830a85d6599de5891fe9e717d2 (patch) | |
| tree | 2ebec8c8aaa86693b0b94da193650d0bb8b0d8ca /mm/shmem.c | |
| parent | d6a24df00638a09abd8fb99bdb5a1c7fdd536e59 (diff) | |
| download | lwn-46c9a946d766fa830a85d6599de5891fe9e717d2.tar.gz lwn-46c9a946d766fa830a85d6599de5891fe9e717d2.zip | |
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 <arnd@arndb.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
| -rw-r--r-- | mm/shmem.c | 3 |
1 files changed, 2 insertions, 1 deletions
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 <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> @@ -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); |