The patch shows number of opened instances of ploop-device (plo->open_count) in /sys/block/ploopN/pstate/open_count. This will allow userspace to decide whether a ploop-device is used by someone (e.g. backup) by scanning the open_count for all ploop-devices.
https://jira.sw.ru/browse/PSBM-24754 Signed-off-by: Maxim Patlasov <mpatla...@parallels.com> --- drivers/block/ploop/sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/block/ploop/sysfs.c b/drivers/block/ploop/sysfs.c index 5c31826..3ef53ac 100644 --- a/drivers/block/ploop/sysfs.c +++ b/drivers/block/ploop/sysfs.c @@ -383,6 +383,11 @@ static u32 show_event(struct ploop_device * plo) return ret; } +static u32 show_open_count(struct ploop_device * plo) +{ + return atomic_read(&plo->open_count); +} + static ssize_t print_cookie(struct ploop_device * plo, char * page) { return sprintf(page, "%s\n", plo->cookie); @@ -466,6 +471,7 @@ static struct attribute *state_attributes[] = { _A(top), _A(event), _A3(cookie), + _A(open_count), NULL }; -- 1.9.3 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
