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 fd12acccf76e1a56f073322414cd43cbffa598ba
Author: Andrey Smetanin <asmeta...@virtuozzo.com>
Date: Tue May 19 08:27:04 2015 +0400
ploop: add ioctl to limit size of top delta (v2)
customer created an online backup => backup.tib file. Most probably the
.tib file is inconsistent and in order to correctly access data inside
we need to replay the journal.
=> We have to provide to container a bundle of .tib file (read-only) and
a tiny read-writeable ploop delta - journal replayed data will be stored
there.
A cunning customer can notice that the delta is writeble and fill it
with his own data - unlimited.
=> we need an ability to limit the ploop delta max size.
https://jira.sw.ru/browse/PSBM-22002
v2: move declaration of PLOOP_IOC_MAX_DELTA_SIZE
Signed-off-by: Andrew Vagin <ava...@openvz.org>
Acked-by: Maxim V. Patlasov <mpatla...@parallels.com>
---
drivers/block/ploop/dev.c | 20 ++++++++++++++++++++
drivers/block/ploop/fmt_ploop1.c | 5 +++++
include/linux/ploop/ploop.h | 2 ++
include/linux/ploop/ploop_if.h | 3 +++
4 files changed, 30 insertions(+)
diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index 0124349..33f8442 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -2770,6 +2770,7 @@ init_delta(struct ploop_device * plo, struct ploop_ctl *
ctl, int level)
delta->plo = plo;
delta->ops = ops;
delta->flags = ctl->pctl_flags & PLOOP_FMT_FLAGS;
+ delta->max_delta_size = ULLONG_MAX;
KOBJECT_INIT(&delta->kobj, &ploop_delta_ktype);
return delta;
@@ -2780,6 +2781,22 @@ out_err:
}
+static int ploop_set_max_delta_size(struct ploop_device *plo, unsigned long
arg)
+{
+ struct ploop_delta * top_delta = ploop_top_delta(plo);
+ u64 max_delta_size;
+
+ if (copy_from_user(&max_delta_size, (void*)arg, sizeof(u64)))
+ return -EFAULT;
+
+ if (top_delta == NULL)
+ return -EINVAL;
+
+ top_delta->max_delta_size = max_delta_size;
+
+ return 0;
+}
+
static int ploop_add_delta(struct ploop_device * plo, unsigned long arg)
{
int err;
@@ -4419,6 +4436,9 @@ static int ploop_ioctl(struct block_device *bdev, fmode_t
fmode, unsigned int cm
case PLOOP_IOC_DISCARD_WAIT:
err = ploop_discard_wait_ioc(plo);
break;
+ case PLOOP_IOC_MAX_DELTA_SIZE:
+ err = ploop_set_max_delta_size(plo, arg);
+ break;
default:
err = -EINVAL;
}
diff --git a/drivers/block/ploop/fmt_ploop1.c b/drivers/block/ploop/fmt_ploop1.c
index 5ce6915..585f6ce 100644
--- a/drivers/block/ploop/fmt_ploop1.c
+++ b/drivers/block/ploop/fmt_ploop1.c
@@ -222,6 +222,11 @@ static void
ploop1_allocate(struct ploop_delta * delta, struct ploop_request * preq,
struct bio_list * sbl, unsigned int size)
{
+ if (delta->io.alloc_head >=
+ (delta->max_delta_size >> delta->cluster_log)) {
+ ploop_fail_request(preq, -E2BIG);
+ return;
+ }
delta->io.ops->submit_alloc(&delta->io, preq, sbl, size);
}
diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h
index 434789e..ae3dbfc 100644
--- a/include/linux/ploop/ploop.h
+++ b/include/linux/ploop/ploop.h
@@ -286,6 +286,8 @@ struct ploop_delta
struct ploop_delta_ops *ops;
struct kobject kobj;
+
+ u64 max_delta_size; /* in sectors */
};
struct ploop_tunable
diff --git a/include/linux/ploop/ploop_if.h b/include/linux/ploop/ploop_if.h
index 45b74fc..aacddb3 100644
--- a/include/linux/ploop/ploop_if.h
+++ b/include/linux/ploop/ploop_if.h
@@ -299,6 +299,9 @@ struct ploop_track_extent
/* Filter extents with sizes less than arg */
#define PLOOP_IOC_FBFILTER _IOR(PLOOPCTLTYPE, 27, unsigned long)
+/* Set maximum size for the top delta . */
+#define PLOOP_IOC_MAX_DELTA_SIZE _IOW(PLOOPCTLTYPE, 28, __u64)
+
/* Events exposed via /sys/block/ploopN/pstate/event */
#define PLOOP_EVENT_ABORTED 1
#define PLOOP_EVENT_STOPPED 2
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