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-rw-r--r--drivers/md/dm-snap.c9
-rw-r--r--drivers/md/dm-table.c36
-rw-r--r--include/linux/device-mapper.h2
3 files changed, 35 insertions, 12 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 62479ac4baf7..70bb0e8b62ce 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1105,6 +1105,7 @@ 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;
@@ -1135,11 +1136,19 @@ 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";
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 7210e5392cc4..f9e8f0bef332 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -365,6 +365,26 @@ static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
}
/*
+ * Convert the path to a device
+ */
+dev_t dm_get_dev_t(const char *path)
+{
+ dev_t uninitialized_var(dev);
+ struct block_device *bdev;
+
+ bdev = lookup_bdev(path);
+ if (IS_ERR(bdev))
+ dev = name_to_dev_t(path);
+ else {
+ dev = bdev->bd_dev;
+ bdput(bdev);
+ }
+
+ return dev;
+}
+EXPORT_SYMBOL_GPL(dm_get_dev_t);
+
+/*
* Add a device to the list, or just increment the usage count if
* it's already present.
*/
@@ -372,23 +392,15 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
struct dm_dev **result)
{
int r;
- dev_t uninitialized_var(dev);
+ dev_t dev;
struct dm_dev_internal *dd;
struct dm_table *t = ti->table;
- struct block_device *bdev;
BUG_ON(!t);
- /* convert the path to a device */
- bdev = lookup_bdev(path);
- if (IS_ERR(bdev)) {
- dev = name_to_dev_t(path);
- if (!dev)
- return -ENODEV;
- } else {
- dev = bdev->bd_dev;
- bdput(bdev);
- }
+ dev = dm_get_dev_t(path);
+ if (!dev)
+ return -ENODEV;
dd = find_device(&t->devices, dev);
if (!dd) {
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 82ae3b5e2c45..0830c9e86f0d 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -124,6 +124,8 @@ struct dm_dev {
char name[16];
};
+dev_t dm_get_dev_t(const char *path);
+
/*
* Constructors should call these functions to ensure destination devices
* are opened/closed correctly.