[PATCH 5/6] zram: register default groups with device_add_disk()

Hannes Reinecke
2018-07-30T07:12:26Z

Register default sysfs groups during device_add-disk() to avoid a
race condition with udev during startup.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
---
drivers/block/zram/zram_drv.c | 28 +++++++---------------------
1 file changed, 7 insertions(+), 21 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 2907a8156aaf..fc3626cb7fe5 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1618,6 +1618,11 @@ static const struct attribute_group zram_disk_attr_group = {
.attrs = zram_disk_attrs,
};

+static const struct attribute_group *zram_disk_attr_groups[] = {
+ &zram_disk_attr_group,
+ NULL,
+};
+
/*
* Allocate and initialize new zram device. the function returns
* '>= 0' device_id upon success, and negative value otherwise.
@@ -1698,24 +1703,14 @@ static int zram_add(void)

zram->disk->queue->backing_dev_info->capabilities |=
(BDI_CAP_STABLE_WRITES | BDI_CAP_SYNCHRONOUS_IO);
- add_disk(zram->disk);
-
- ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj,
- &zram_disk_attr_group);
- if (ret < 0) {
- pr_err("Error creating sysfs group for device %d\n",
- device_id);
- goto out_free_disk;
- }
+ device_add_disk(NULL, zram->disk, zram_disk_attr_groups);
+
strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor));

zram_debugfs_register(zram);
pr_info("Added device: %s\n", zram->disk->disk_name);
return device_id;

-out_free_disk:
- del_gendisk(zram->disk);
- put_disk(zram->disk);
out_free_queue:
blk_cleanup_queue(queue);
out_free_idr:
@@ -1744,15 +1739,6 @@ static int zram_remove(struct zram *zram)
mutex_unlock(&bdev->bd_mutex);

zram_debugfs_unregister(zram);
- /*
- * Remove sysfs first, so no one will perform a disksize
- * store while we destroy the devices. This also helps during
- * hot_remove -- zram_reset_device() is the last holder of
- * ->init_lock, no later/concurrent disksize_store() or any
- * other sysfs handlers are possible.
- */
- sysfs_remove_group(&disk_to_dev(zram->disk)->kobj,
- &zram_disk_attr_group);

/* Make sure all the pending I/O are finished */
fsync_bdev(bdev);
--
2.12.3