From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: [PATCH V6 3/4] sd_zbc: Fix report zones buffer allocation Date: Thu, 11 Jul 2019 20:27:37 -0400 Message-ID: References: <20190701050918.27511-1-damien.lemoal@wdc.com> <20190701050918.27511-4-damien.lemoal@wdc.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190701050918.27511-4-damien.lemoal@wdc.com> (Damien Le Moal's message of "Mon, 1 Jul 2019 14:09:17 +0900") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Damien Le Moal Cc: Jens Axboe , "Martin K . Petersen" , Mike Snitzer , linux-f2fs-devel@lists.sourceforge.net, linux-block@vger.kernel.org, dm-devel@redhat.com, linux-scsi@vger.kernel.org, Jaegeuk Kim , Christoph Hellwig , Bart Van Assche List-Id: linux-scsi@vger.kernel.org Damien, > During disk scan and revalidation done with sd_revalidate(), the zones > of a zoned disk are checked using the helper function > blk_revalidate_disk_zones() if a configuration change is detected > (change in the number of zones or zone size). The function > blk_revalidate_disk_zones() issues report_zones calls that are very > large, that is, to obtain zone information for all zones of the disk > with a single command. The size of the report zones command buffer > necessary for such large request generally is lower than the disk > max_hw_sectors and KMALLOC_MAX_SIZE (4MB) and succeeds on boot (no > memory fragmentation), but often fail at run time (e.g. hot-plug > event). This causes the disk revalidation to fail and the disk > capacity to be changed to 0. Probably easiest to funnel this through block with the rest of the series. Acked-by: Martin K. Petersen -- Martin K. Petersen Oracle Linux Engineering