The commit is pushed to "branch-rh7-3.10.0-123.1.2-ovz" and will appear at
https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-123.1.2.vz7.5.1
------>
commit ace664d9412efd2fa814851b0be55751dc9ed13a
Author: Andrey Smetanin <asmeta...@virtuozzo.com>
Date: Tue May 19 08:27:05 2015 +0400
ploop: ensure non-empty delta list on running ploop
The only allowed use-case for delta removal on running ploop is the merge
operation. But merge never removes base delta. Hence, we can prohibit
base delta removal if ploop is in RUNNING state. This resolves the following
issue: buggy userspace removes all deltas from a running ploop, but leaves
ploop in RUNNING state making any further ploop-mount impossible.
https://jira.sw.ru/browse/PSBM-25102
Signed-off-by: Maxim Patlasov <mpatla...@parallels.com>
Acked-by: Pavel Emelyanov <xe...@parallels.com>
---
drivers/block/ploop/dev.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index 33f8442..d2a9eb4 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -3173,6 +3173,12 @@ static int ploop_del_delta(struct ploop_device * plo,
unsigned long arg)
if (plo->maintenance_type != PLOOP_MNTN_OFF)
return -EBUSY;
+ if (level == 0 && test_bit(PLOOP_S_RUNNING, &plo->state)) {
+ printk(KERN_INFO "Can't del base delta on running ploop%d\n",
+ plo->index);
+ return -EBUSY;
+ }
+
delta = find_delta(plo, level);
if (delta == NULL)
@@ -3197,6 +3203,8 @@ static int ploop_del_delta(struct ploop_device * plo,
unsigned long arg)
delta->ops->stop(delta);
delta->ops->destroy(delta);
kobject_put(&delta->kobj);
+ BUG_ON(test_bit(PLOOP_S_RUNNING, &plo->state) &&
+ list_empty(&plo->map.delta_list));
return 0;
}
@@ -3573,6 +3581,7 @@ static int ploop_start(struct ploop_device * plo, struct
block_device *bdev)
wake_up_process(plo->thread);
set_bit(PLOOP_S_RUNNING, &plo->state);
+ BUG_ON(list_empty(&plo->map.delta_list));
return 0;
out_err:
@@ -3605,8 +3614,11 @@ static int ploop_stop(struct ploop_device * plo, struct
block_device *bdev)
if (!test_bit(PLOOP_S_RUNNING, &plo->state))
return -EINVAL;
- if (list_empty(&plo->map.delta_list))
+ if (list_empty(&plo->map.delta_list)) {
+ printk(KERN_INFO "stop ploop%d failed (no deltas)\n",
+ plo->index);
return -ENOENT;
+ }
cnt = atomic_read(&plo->open_count);
if (cnt > 1) {
@@ -3755,6 +3767,7 @@ static int ploop_clear(struct ploop_device * plo, struct
block_device * bdev)
plo->maintenance_type = PLOOP_MNTN_OFF;
plo->bd_size = 0;
plo->state = (1 << PLOOP_S_CHANGED);
+ BUG_ON(test_bit(PLOOP_S_RUNNING, &plo->state));
return 0;
}
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