[bug report] scsi: sd_zbc: emulate ZONE_APPEND commands

From: Dan Carpenter <dan.carpenter@oracle.com>
To: johannes.thumshirn@wdc.com
Cc: linux-scsi@vger.kernel.org, Michal Hocko <mhocko@kernel.org>
Subject: [bug report] scsi: sd_zbc: emulate ZONE_APPEND commands
Date: Tue, 16 Feb 2021 22:39:13 +0300	[thread overview]
Message-ID: <YCuvSfKw4qEQBr/t@mwanda> (raw)

Hello Johannes Thumshirn,

The patch 5795eb443060: "scsi: sd_zbc: emulate ZONE_APPEND commands"
from May 12, 2020, leads to the following static checker warning:

	drivers/scsi/sd_zbc.c:741 sd_zbc_revalidate_zones()
	error: kvmalloc() only makes sense with GFP_KERNEL

drivers/scsi/sd_zbc.c
   721          /*
   722           * There is nothing to do for regular disks, including host-aware disks
   723           * that have partitions.
   724           */
   725          if (!blk_queue_is_zoned(q))
   726                  return 0;
   727  
   728          /*
   729           * Make sure revalidate zones are serialized to ensure exclusive
   730           * updates of the scsi disk data.
   731           */
   732          mutex_lock(&sdkp->rev_mutex);
   733  
   734          if (sdkp->zone_blocks == zone_blocks &&
   735              sdkp->nr_zones == nr_zones &&
   736              disk->queue->nr_zones == nr_zones)
   737                  goto unlock;
   738  
   739          sdkp->zone_blocks = zone_blocks;
   740          sdkp->nr_zones = nr_zones;
   741          sdkp->rev_wp_offset = kvcalloc(nr_zones, sizeof(u32), GFP_NOIO);
                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
We're passing GFP_NOIO here so it just defaults to kcalloc() and will
not vmalloc() the memory.

   742          if (!sdkp->rev_wp_offset) {
   743                  ret = -ENOMEM;
   744                  goto unlock;
   745          }
   746  
   747          ret = blk_revalidate_disk_zones(disk, sd_zbc_revalidate_zones_cb);
   748  

regards,
dan carpenter