[PATCH 17/24] dm-snap: simplify the origin_dev == cow_dev check in snapshot_ctr

Christoph Hellwig
2023-05-31T12:58:54Z

Use the block_device acquired in dm_get_device for the check instead
of doing an extra lookup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
---
drivers/md/dm-snap.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 9c49f53760d066..7832974b73eb03 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1241,7 +1241,6 @@ 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 int args_used, num_flush_bios = 1;
fmode_t origin_mode = FMODE_READ;

@@ -1279,24 +1278,21 @@ 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";
goto bad_cow;
}
+ if (s->cow->bdev && s->cow->bdev == s->origin->bdev) {
+ ti->error = "COW device cannot be the same as origin device";
+ r = -EINVAL;
+ goto bad_store;
+ }

r = dm_exception_store_create(ti, argc, argv, s, &args_used, &s->store);
if (r) {
--
2.39.2