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Mon, 30 Nov 2020 10:09:25 +0100 (CET) Date: Mon, 30 Nov 2020 10:09:25 +0100 From: Jan Kara To: Christoph Hellwig Message-ID: <20201130090925.GB11250@quack2.suse.cz> References: <20201128161510.347752-1-hch@lst.de> <20201128161510.347752-17-hch@lst.de> MIME-Version: 1.0 In-Reply-To: <20201128161510.347752-17-hch@lst.de> User-Agent: Mutt/1.10.1 (2018-07-13) X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-loop: dm-devel@redhat.com Cc: Jens Axboe , Jan Kara , Mike Snitzer , linux-mm@kvack.org, Greg Kroah-Hartman , Jan Kara , Josef Bacik , Coly Li , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, dm-devel@redhat.com, linux-mtd@lists.infradead.org, Johannes Thumshirn , Tejun Heo , linux-bcache@vger.kernel.org Subject: Re: [dm-devel] [PATCH 16/45] block: switch bdgrab to use igrab X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Sat 28-11-20 17:14:41, Christoph Hellwig wrote: > All of the current callers already have a reference, but to prepare for > additional users ensure bdgrab returns NULL if the block device is beeing ^^^ being > freed. > > Signed-off-by: Christoph Hellwig Otherwise looks good. Feel free to add: Reviewed-by: Jan Kara Honza > --- > fs/block_dev.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/block_dev.c b/fs/block_dev.c > index d707ab376da86e..962fabe8a67b83 100644 > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -894,10 +894,14 @@ static struct block_device *bdget(dev_t dev) > /** > * bdgrab -- Grab a reference to an already referenced block device > * @bdev: Block device to grab a reference to. > + * > + * Returns the block_device with an additional reference when successful, > + * or NULL if the inode is already beeing freed. > */ > struct block_device *bdgrab(struct block_device *bdev) > { > - ihold(bdev->bd_inode); > + if (!igrab(bdev->bd_inode)) > + return NULL; > return bdev; > } > EXPORT_SYMBOL(bdgrab); > -- > 2.29.2 > -- Jan Kara SUSE Labs, CR -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel