On 2018/6/22 9:48 PM, Arnd Bergmann wrote: > The get_seconds function is deprecated now since it returns a 32-bit > value that will eventually overflow, and we are replacing it throughout > the kernel with ktime_get_seconds() or ktime_get_real_seconds() that > return a time64_t. > > bcache uses get_seconds() to read the current system time and store it in > the superblock as well as in uuid_entry structures that are user visible. > > Unfortunately, the two structures in are still limited to 32 bits, so this > won't fix any real problems but will still overflow in year 2106. Let's > at least document that properly, in case we get an updated format in the > future it can be fixed. We still have a long time before the overflow > and checking the tools at https://github.com/koverstreet/bcache-tools > reveals no access to any of them. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Added to 4.19 for-next. Thanks. Coly Li > --- > drivers/md/bcache/super.c | 12 ++++++------ > include/uapi/linux/bcache.h | 4 ++-- > 2 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c > index fa4058e43202..74746d8ee05e 100644 > --- a/drivers/md/bcache/super.c > +++ b/drivers/md/bcache/super.c > @@ -181,7 +181,7 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev, > goto err; > } > > - sb->last_mount = get_seconds(); > + sb->last_mount = (u32)ktime_get_real_seconds(); > err = NULL; > > get_page(bh->b_page); > @@ -701,7 +701,7 @@ static void bcache_device_detach(struct bcache_device *d) > > SET_UUID_FLASH_ONLY(u, 0); > memcpy(u->uuid, invalid_uuid, 16); > - u->invalidated = cpu_to_le32(get_seconds()); > + u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds()); > bch_uuid_write(d->c); > } > > @@ -1027,7 +1027,7 @@ void bch_cached_dev_detach(struct cached_dev *dc) > int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c, > uint8_t *set_uuid) > { > - uint32_t rtime = cpu_to_le32(get_seconds()); > + uint32_t rtime = cpu_to_le32((u32)ktime_get_real_seconds()); > struct uuid_entry *u; > struct cached_dev *exist_dc, *t; > > @@ -1070,7 +1070,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c, > (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE || > BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) { > memcpy(u->uuid, invalid_uuid, 16); > - u->invalidated = cpu_to_le32(get_seconds()); > + u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds()); > u = NULL; > } > > @@ -1390,7 +1390,7 @@ int bch_flash_dev_create(struct cache_set *c, uint64_t size) > > get_random_bytes(u->uuid, 16); > memset(u->label, 0, 32); > - u->first_reg = u->last_reg = cpu_to_le32(get_seconds()); > + u->first_reg = u->last_reg = cpu_to_le32((u32)ktime_get_real_seconds()); > > SET_UUID_FLASH_ONLY(u, 1); > u->sectors = size >> 9; > @@ -1894,7 +1894,7 @@ static void run_cache_set(struct cache_set *c) > goto err; > > closure_sync(&cl); > - c->sb.last_mount = get_seconds(); > + c->sb.last_mount = (u32)ktime_get_real_seconds(); > bcache_write_super(c); > > list_for_each_entry_safe(dc, t, &uncached_devices, list) > diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h > index 821f71a2e48f..8d19e02d752a 100644 > --- a/include/uapi/linux/bcache.h > +++ b/include/uapi/linux/bcache.h > @@ -195,7 +195,7 @@ struct cache_sb { > }; > }; > > - __u32 last_mount; /* time_t */ > + __u32 last_mount; /* time overflow in y2106 */ > > __u16 first_bucket; > union { > @@ -318,7 +318,7 @@ struct uuid_entry { > struct { > __u8 uuid[16]; > __u8 label[32]; > - __u32 first_reg; > + __u32 first_reg; /* time overflow in y2106 */ > __u32 last_reg; > __u32 invalidated; > > -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
