From fc033a9dc4a8f9f808de77e5faa0d8840e8e165f Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 11 Mar 2021 16:59:56 +0100 Subject: [PATCH] Revert "zram: register default groups with device_add_disk()" This reverts commit 70a534ad4a4ee7d528c81ef9b2caf0ae3e302831. The patch series submitted for the 4.19-stable branch: https://lore.kernel.org/r/20210223092859.17033-1-jefflexu@linux.alibaba.com should be reverted from the android-4.19-stable branch as it breaks the ABI for device_add_disk() and the issue the series is resolving does not affect Android devices. So revert the whole thing. Bug: 161946584 Signed-off-by: Greg Kroah-Hartman Change-Id: I36971c96eb15cdf64709d1fa3186cd107946b541 --- drivers/block/zram/zram_drv.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index a1bb9db7576b..d1a254cc1b84 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1884,11 +1884,6 @@ 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. @@ -1971,14 +1966,24 @@ static int zram_add(void) zram->disk->queue->backing_dev_info->capabilities |= (BDI_CAP_STABLE_WRITES | BDI_CAP_SYNCHRONOUS_IO); - device_add_disk(NULL, zram->disk, zram_disk_attr_groups); + 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; + } 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: @@ -2007,6 +2012,15 @@ 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);