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| author | Gerald Schaefer <gerald.schaefer@linux.ibm.com> | 2022-10-27 17:19:38 +0300 |
|---|---|---|
| committer | Alexander Gordeev <agordeev@linux.ibm.com> | 2022-11-16 13:39:11 +0300 |
| commit | a41a11b4009580edb6e2b4c76e5e2ee303f87157 (patch) | |
| tree | ce68fae9954386e4727b35ae45ddc8e12b3cbeea /drivers/s390 | |
| parent | 30d17fac6aaedb40d111bb159f4b35525637ea78 (diff) | |
| download | linux-a41a11b4009580edb6e2b4c76e5e2ee303f87157.tar.xz | |
s390/dcssblk: fix deadlock when adding a DCSS
After the rework from commit 1ebe2e5f9d68 ("block: remove
GENHD_FL_EXT_DEVT"), when calling device_add_disk(), dcssblk will end up
in disk_scan_partitions(), and not break out early w/o GENHD_FL_NO_PART.
This will trigger implicit open/release via blkdev_get/put_whole()
later. dcssblk_release() will then deadlock on dcssblk_devices_sem
semaphore, which is already held from dcssblk_add_store() when calling
device_add_disk().
dcssblk does not support partitions (DCSSBLK_MINORS_PER_DISK == 1), and
never scanned partitions before. Therefore restore the previous
behavior, and explicitly disallow partition scanning by setting the
GENHD_FL_NO_PART flag. This will also prevent this deadlock scenario.
Fixes: 1ebe2e5f9d68 ("block: remove GENHD_FL_EXT_DEVT")
Cc: <stable@vger.kernel.org> # 5.17+
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/block/dcssblk.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 93b80da60277..b392b9f5482e 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -636,6 +636,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char dev_info->gd->minors = DCSSBLK_MINORS_PER_DISK; dev_info->gd->fops = &dcssblk_devops; dev_info->gd->private_data = dev_info; + dev_info->gd->flags |= GENHD_FL_NO_PART; blk_queue_logical_block_size(dev_info->gd->queue, 4096); blk_queue_flag_set(QUEUE_FLAG_DAX, dev_info->gd->queue); |