From: Christoph Hellwig <hch@lst.de>
To: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
linux-block@vger.kernel.org
Subject: Re: [PATCH] block: always remove partitions from blk_drop_partitions()
Date: Wed, 15 Jul 2020 11:39:47 +0200 [thread overview]
Message-ID: <20200715093947.GA27731@lst.de> (raw)
In-Reply-To: <20200715083619.624249-1-ming.lei@redhat.com>
On Wed, Jul 15, 2020 at 04:36:19PM +0800, Ming Lei wrote:
> In theory, when GENHD_FL_NO_PART_SCAN is set, no partitions can be created
> on one disk. However, ioctl(BLKPG, BLKPG_ADD_PARTITION) doesn't check
> GENHD_FL_NO_PART_SCAN, so partitions still can be added even though
> GENHD_FL_NO_PART_SCAN is set.
>
> So far blk_drop_partitions() only removes partitions when disk_part_scan_enabled()
> return true. This way can make ghost partition on loop device after changing/clearing
> FD in case that PARTSCAN is disabled, such as partitions can be added
> via 'parted' on loop disk even though GENHD_FL_NO_PART_SCAN is set.
>
> Fix this issue by always removing partitions in blk_drop_partitions(), and
> this way is correct because the current code supposes that no partitions
> can be added in case of GENHD_FL_NO_PART_SCAN.
The changelog has a few overly long lines.
Otherwise:
Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2020-07-15 9:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-15 8:36 [PATCH] block: always remove partitions from blk_drop_partitions() Ming Lei
2020-07-15 9:39 ` Christoph Hellwig [this message]
2020-07-15 15:14 ` Jens Axboe
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