On Tue, Jun 24, 2014 at 07:21:12AM +0000, Minchan Kim wrote: > On Tue, Jun 24, 2014 at 12:34:50PM +0600, Alexander E. Patrakov wrote: > > 24.06.2014 12:22, Minchan Kim wrote: > > > > > >Hello, > > > > > >Sorry for the late response. > > > > Better late than never. > > > > >If I parse your problem correctly, you meant that changing disksize is > > >failed while someone opens /dev/zram0? > > > > > >I tried test which opens "/dev/zram0" with O_RDWR and sleep forever > > >and then echo $((512<<20)) > /sys/block/zram0/disksize is successful. > > >IOW, it's okay with me. > > > > No, this is only a part of the problem. A valid test would be: > > > > 0. Reset the unused zram device. > > 1. Use a program that opens /dev/zram0 with O_RDWR and sleeps until killed. > > 2. While that program sleeps, echo the correct value to > > /sys/block/zram0/disksize. > > 3. Verify (e.g. in /proc/partitions) that the disk size is applied > > correctly. It is. > > 4. While that program still sleeps, attempt to mkswap /dev/zram0. > > This fails: > > > > mkswap: error: swap area needs to be at least 40 KiB > > > > There is nothing in dmesg. > > Thanks. I could reproduce. > When I read strace result, fstat access closed fd which seem to be > a culprit. > > Cced util-linux. When I read disk-utils/mkswap.c, it's not a problem of mkswap. The problem is ioctl(fd, BLKGETSIZE64, bytes) is not work in your scenario. IOW, kernel fault. Hmm,, will investgate it. Thanks for the report! -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
