On 04/19/2019 11:24 AM, Coly Li wrote:
> This patch adds return value to register_bdev(). Then if failure happens
> inside register_bdev(), its caller register_bcache() may detect and
> handle the failure more properly.
>
> Signed-off-by: Coly Li <colyli@xxxxxxx>
> ---
> drivers/md/bcache/super.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index 400af446c372..a435c506edba 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -1281,7 +1281,7 @@ static int cached_dev_init(struct cached_dev *dc, unsigned int block_size)
>
> /* Cached device - bcache superblock */
>
> -static void register_bdev(struct cache_sb *sb, struct page *sb_page,
> +static int register_bdev(struct cache_sb *sb, struct page *sb_page,
> struct block_device *bdev,
> struct cached_dev *dc)
> {
> @@ -1319,10 +1319,11 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
> BDEV_STATE(&dc->sb) == BDEV_STATE_STALE)
> bch_cached_dev_run(dc);
>
> - return;
> + return 0;
> err:
> pr_notice("error %s: %s", dc->backing_dev_name, err);
> bcache_device_stop(&dc->disk);
So register_bdev has couple of goto err; calls where kobject interface
is used directly :-
register_bdev
kobject_add
and
indirectly :-
register_bdev
bch_cache_accounting_add_kobjs
kobject_add
Here we return -EIO, we should catch the error code from kobject calls
and return that error instead of -EIO. Any thoughts ?
> + return -EIO;
> }
>
> /* Flash only volumes */
> @@ -2273,7 +2274,7 @@ static bool bch_is_open(struct block_device *bdev)
> static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
> const char *buffer, size_t size)
> {
> - ssize_t ret = size;
> + ssize_t ret = -EINVAL;
> const char *err = "cannot allocate memory";
> char *path = NULL;
> struct cache_sb *sb = NULL;
> @@ -2307,7 +2308,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
> if (!IS_ERR(bdev))
> bdput(bdev);
> if (attr == &ksysfs_register_quiet)
> - goto out;
> + goto quiet_out;
> }
> goto err;
> }
> @@ -2328,8 +2329,10 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
> goto err_close;
>
> mutex_lock(&bch_register_lock);
> - register_bdev(sb, sb_page, bdev, dc);
> + ret = register_bdev(sb, sb_page, bdev, dc);
> mutex_unlock(&bch_register_lock);
> + if (ret < 0)
> + goto err;
> } else {
> struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
>
> @@ -2339,6 +2342,8 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
> if (register_cache(sb, sb_page, bdev, ca) != 0)
> goto err;
> }
> +quiet_out:
> + ret = size;
> out:
> if (sb_page)
> put_page(sb_page);
> @@ -2351,7 +2356,6 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
> blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
> err:
> pr_info("error %s: %s", path, err);
> - ret = -EINVAL;
> goto out;
> }
>
>
