[linux-lvm] LVM miscalculates bitmap size for RAID1 and small extent

[Andrei Borzenkov]

Using lvm2-2.02.98-43.17.1 in openSUSE 13.2

bor at opensuse:~/src/lvm2> dd if=/dev/zero of=/tmp/sparse2 bs=1 count=1 seek=100M
bor at opensuse:~/src/lvm2> dd if=/dev/zero of=/tmp/sparse1 bs=1 count=1 seek=100M
bor at opensuse:~/src/lvm2> sudo losetup -f --show /tmp/sparse1
/dev/loop0
bor at opensuse:~/src/lvm2> sudo losetup -f --show /tmp/sparse2
/dev/loop1
bor at opensuse:~/src/lvm2> sudo pvcreate /dev/loop0
bor at opensuse:~/src/lvm2> sudo pvcreate /dev/loop1
bor at opensuse:~/src/lvm2> sudo vgcreate -s 1k x_test /dev/loop0 /dev/loop1
bor at opensuse:~/src/lvm2> sudo lvcreate -n r1 -L 80m x_test -m 1 

Kernel messages

мар 15 20:06:45 opensuse.site sudo[4320]: bor : TTY=pts/1 ; PWD=/home/bor/src/lvm2 ; USER=root ; COMMAND=/sbin/lvcreate -n r1 -L 80m x_test -m 1
мар 15 20:06:45 opensuse.site kernel: device-mapper: raid: Superblocks created for new array
мар 15 20:06:45 opensuse.site kernel: md/raid1:mdX: not clean -- starting background reconstruction
мар 15 20:06:45 opensuse.site kernel: md/raid1:mdX: active with 2 out of 2 mirrors
мар 15 20:06:45 opensuse.site kernel: Choosing daemon_sleep default (5 sec)
мар 15 20:06:45 opensuse.site kernel: created bitmap (1 pages) for device mdX
мар 15 20:06:45 opensuse.site kernel: attempt to access beyond end of device
мар 15 20:06:45 opensuse.site kernel: dm-7: rw=7185, want=9, limit=2

Individual constituents

bor at opensuse:~/src/lvm2> sudo dmsetup table x_test-r1_rimage_1
0 163840 linear 7:1 2050
bor at opensuse:~/src/lvm2> sudo dmsetup table x_test-r1_rimage_0
0 163840 linear 7:0 2050
bor at opensuse:~/src/lvm2> sudo dmsetup table x_test-r1_rmeta_1
0 2 linear 7:1 2048
bor at opensuse:~/src/lvm2> sudo dmsetup table x_test-r1_rmeta_0
0 2 linear 7:0 2048


Is it known problem? I could not find anything obvious in commit log.