diff options
| -rw-r--r-- | drivers/md/dm-snap.c | 9 | ||||
| -rw-r--r-- | drivers/md/dm-table.c | 36 | ||||
| -rw-r--r-- | include/linux/device-mapper.h | 2 |
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. |