bcache: Warn when a device is already registered.
Signed-off-by: Gabriel de Perthuis <g2p.code+bcache@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index f88e2b6..3de5626 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1786,6 +1786,36 @@
kobj_attribute_write(register, register_bcache);
kobj_attribute_write(register_quiet, register_bcache);
+static bool bch_is_open_backing(struct block_device *bdev) {
+ struct cache_set *c, *tc;
+ struct cached_dev *dc, *t;
+
+ list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
+ list_for_each_entry_safe(dc, t, &c->cached_devs, list)
+ if (dc->bdev == bdev)
+ return true;
+ list_for_each_entry_safe(dc, t, &uncached_devices, list)
+ if (dc->bdev == bdev)
+ return true;
+ return false;
+}
+
+static bool bch_is_open_cache(struct block_device *bdev) {
+ struct cache_set *c, *tc;
+ struct cache *ca;
+ unsigned i;
+
+ list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
+ for_each_cache(ca, c, i)
+ if (ca->bdev == bdev)
+ return true;
+ return false;
+}
+
+static bool bch_is_open(struct block_device *bdev) {
+ return bch_is_open_cache(bdev) || bch_is_open_backing(bdev);
+}
+
static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
const char *buffer, size_t size)
{
@@ -1810,8 +1840,13 @@
FMODE_READ|FMODE_WRITE|FMODE_EXCL,
sb);
if (IS_ERR(bdev)) {
- if (bdev == ERR_PTR(-EBUSY))
- err = "device busy";
+ if (bdev == ERR_PTR(-EBUSY)) {
+ bdev = lookup_bdev(strim(path));
+ if (!IS_ERR(bdev) && bch_is_open(bdev))
+ err = "device already registered";
+ else
+ err = "device busy";
+ }
goto err;
}