zdtm: don't create loops of bind mounts
zdtm: don't create loops of bind mounts

Before this patch crtools/test is bound to crtools/test/dump/crtools.XXXXXXX

It's a main reason why "make clean" deletes all content from crtools/test.

Always when you have a test bind mount. You have a test bind mount, when
a test is executed. You execute a test sometimes. So "make clean"
deletes all content sometimes;).

This patch fixes this problem.

Actually this patch fixes more significan problem. If / is a shared
mount (it's defult in FC19),
$ mount --bind crtools/test crtools/test/dump/crtools.XXXXXXX
will recursively copy all previous bind mounts.

E.g:

cd crtools/test
make -j 4
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.b86wVA ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.DMoEZv ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.b86wVA/dump/crtools-root.DMoEZv ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.oLnVTw ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.DMoEZv/dump/crtools-root.oLnVTw ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.b86wVA/dump/crtools-root.DMoEZv/dump/crtools-root.oLnVTw ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.b86wVA/dump/crtools-root.oLnVTw ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.7zQrDs ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.oLnVTw/dump/crtools-root.7zQrDs ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.DMoEZv/dump/crtools-root.oLnVTw/dump/crtools-root.7zQrDs ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.b86wVA/dump/crtools-root.DMoEZv/dump/crtools-root.oLnVTw/dump/crtools-root.7zQrDs ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.b86wVA/dump/crtools-root.oLnVTw/dump/crtools-root.7zQrDs ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.DMoEZv/dump/crtools-root.7zQrDs ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.b86wVA/dump/crtools-root.DMoEZv/dump/crtools-root.7zQrDs ext4 rw,relatime,data=ordered 0 0
/dev/mapper/vg-lv_root /root/crtools/test/dump/crtools-root.b86wVA/dump/crtools-root.7zQrDs ext4 rw,relatime,data=ordered 0 0

make -j 32 generates ~2^32 mounts.

Signed-off-by: Andrey Vagin <74c05afa918858348d6db8037d82fa8124870113@openvz.org>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.com>

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