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authorColy Li <colyli@suse.de>2019-04-25 00:48:38 +0800
committerJens Axboe <axboe@kernel.dk>2019-04-24 10:56:28 -0600
commitbb6d355c2aff42d4075a8e7428dd72cb009d6143 (patch)
tree48f743bf4650553de493cb3bfb41edc89441574b /drivers/md
parent88c12d42d2bb6e05deb3cfd24d12f6fe80544575 (diff)
downloadlinux-bb6d355c2aff42d4075a8e7428dd72cb009d6143.tar.gz
bcache: Add comments for blkdev_put() in registration code path
Add comments to explain why in register_bcache() blkdev_put() won't be called in two location. Add comments to explain why blkdev_put() must be called in register_cache() when cache_alloc() failed. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/bcache/super.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index fde334939545..fa856b2ca7af 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2189,6 +2189,12 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
ret = cache_alloc(ca);
if (ret != 0) {
+ /*
+ * If we failed here, it means ca->kobj is not initialized yet,
+ * kobject_put() won't be called and there is no chance to
+ * call blkdev_put() to bdev in bch_cache_release(). So we
+ * explicitly call blkdev_put() here.
+ */
blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
if (ret == -ENOMEM)
err = "cache_alloc(): -ENOMEM";
@@ -2329,6 +2335,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
mutex_lock(&bch_register_lock);
ret = register_bdev(sb, sb_page, bdev, dc);
mutex_unlock(&bch_register_lock);
+ /* blkdev_put() will be called in cached_dev_free() */
if (ret < 0)
goto err;
} else {
@@ -2337,6 +2344,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
if (!ca)
goto err_close;
+ /* blkdev_put() will be called in bch_cache_release() */
if (register_cache(sb, sb_page, bdev, ca) != 0)
goto err;
}