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Diffstat (limited to 'kernel/drivers/md/dm-snap.c')
-rw-r--r--kernel/drivers/md/dm-snap.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/drivers/md/dm-snap.c b/kernel/drivers/md/dm-snap.c
index 61f184ad0..e108deebb 100644
--- a/kernel/drivers/md/dm-snap.c
+++ b/kernel/drivers/md/dm-snap.c
@@ -1106,6 +1106,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
int i;
int r = -EINVAL;
char *origin_path, *cow_path;
+ dev_t origin_dev, cow_dev;
unsigned args_used, num_flush_bios = 1;
fmode_t origin_mode = FMODE_READ;
@@ -1136,11 +1137,19 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ti->error = "Cannot get origin device";
goto bad_origin;
}
+ origin_dev = s->origin->bdev->bd_dev;
cow_path = argv[0];
argv++;
argc--;
+ cow_dev = dm_get_dev_t(cow_path);
+ if (cow_dev && cow_dev == origin_dev) {
+ ti->error = "COW device cannot be the same as origin device";
+ r = -EINVAL;
+ goto bad_cow;
+ }
+
r = dm_get_device(ti, cow_path, dm_table_get_mode(ti->table), &s->cow);
if (r) {
ti->error = "Cannot get COW device";