Merge "dm snapshot: disallow the COW and origin devices from being identical" (0273eb90) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/md/dm-snap.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -1099,6 +1099,7 @@ 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;

		@@ -1129,11 +1130,19 @@ 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";

+24 −17

Original line number	Diff line number	Diff line
		@@ -363,6 +363,26 @@ static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
		return 0;
		}

		/*
		* 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.
		@@ -371,28 +391,15 @@ 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;
		unsigned int major, minor;
		struct dm_table *t = ti->table;
		char dummy;

		BUG_ON(!t);

		if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
		/* Extract the major/minor numbers */
		dev = MKDEV(major, minor);
		if (MAJOR(dev) != major \|\| MINOR(dev) != minor)
		return -EOVERFLOW;
		} else {
		/* convert the path to a device */
		struct block_device *bdev = lookup_bdev(path);

		if (IS_ERR(bdev))
		return PTR_ERR(bdev);
		dev = bdev->bd_dev;
		bdput(bdev);
		}
		dev = dm_get_dev_t(path);
		if (!dev)
		return -ENODEV;

		dd = find_device(&t->devices, dev);
		if (!dd) {

+2 −0

Original line number	Diff line number	Diff line
		@@ -121,6 +121,8 @@ 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.