From a9dd53adbb84c12f769a862ba2c80404873c2c99 Mon Sep 17 00:00:00 2001 From: Gabriel de Perthuis Date: Sat, 4 May 2013 12:19:41 +0200 Subject: [PATCH] bcache: Warn when a device is already registered. Signed-off-by: Gabriel de Perthuis Signed-off-by: Kent Overstreet --- drivers/md/bcache/super.c | 39 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index f88e2b653a3f..3de5626919ef 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1786,6 +1786,36 @@ static ssize_t register_bcache(struct kobject *, struct kobj_attribute *, 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 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, 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; } -- 2.30.2