From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5D12C4338F for ; Tue, 17 Aug 2021 13:09:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7691260F5E for ; Tue, 17 Aug 2021 13:09:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235448AbhHQNKU (ORCPT ); Tue, 17 Aug 2021 09:10:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:47228 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230415AbhHQNKU (ORCPT ); Tue, 17 Aug 2021 09:10:20 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 36DA560F22; Tue, 17 Aug 2021 13:09:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1629205787; bh=eAJNwq+LR0vGZWapzyEOlD/ux+bUrLIyd52HO8STYtc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=yvx+YmPwu3IclVZ3FyBJ1vW8Cx4JY6xaozjlAH01HnNG0VX6LxT0DRr7zvHM+befh kOnw9shM9edP0OujVaUD0Xn0i6jy08Z8Abxo0s/bwVwGL5G2nt06PTLR5QwPctxLXy TlwQfCNYyyZ4TxF2m5PVOwsCTcP/x22DYBUTs7y8= Date: Tue, 17 Aug 2021 15:09:44 +0200 From: Greg KH To: SelvaKumar S Cc: linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org, dm-devel@redhat.com, kbusch@kernel.org, axboe@kernel.dk, damien.lemoal@wdc.com, asml.silence@gmail.com, johannes.thumshirn@wdc.com, hch@lst.de, willy@infradead.org, kch@kernel.org, martin.petersen@oracle.com, mpatocka@redhat.com, bvanassche@acm.org, djwong@kernel.org, snitzer@redhat.com, agk@redhat.com, selvajove@gmail.com, joshiiitr@gmail.com, nj.shetty@samsung.com, nitheshshetty@gmail.com, joshi.k@samsung.com, javier.gonz@samsung.com Subject: Re: [PATCH 4/7] block: Introduce a new ioctl for simple copy Message-ID: References: <20210817101423.12367-1-selvakuma.s1@samsung.com> <20210817101423.12367-5-selvakuma.s1@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210817101423.12367-5-selvakuma.s1@samsung.com> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Tue, Aug 17, 2021 at 03:44:20PM +0530, SelvaKumar S wrote: > From: Nitesh Shetty > > Add new BLKCOPY ioctl that offloads copying of one or more sources ranges > to a destination in the device. COPY ioctl accepts a 'copy_range' > structure that contains destination (in sectors), no of sources and > pointer to the array of source ranges. Each source range is represented by > 'range_entry' that contains start and length of source ranges (in sectors) > > MAX_COPY_NR_RANGE, limits the number of entries for the IOCTL and > MAX_COPY_TOTAL_LENGTH limits the total copy length, IOCTL can handle. > > Example code, to issue BLKCOPY: > /* Sample example to copy three source-ranges [0, 8] [16, 8] [32,8] to > * [64,24], on the same device */ > > int main(void) > { > int ret, fd; > struct range_entry source_range[] = {{.src = 0, .len = 8}, > {.src = 16, .len = 8}, {.src = 32, .len = 8},}; > struct copy_range cr; > > cr.dest = 64; > cr.nr_range = 3; > cr.range_list = (__u64)&source_range; > > fd = open("/dev/nvme0n1", O_RDWR); > if (fd < 0) return 1; > > ret = ioctl(fd, BLKCOPY, &cr); > if (ret < 0) printf("copy failure\n"); > > close(fd); > > return ret; > } > > Signed-off-by: Nitesh Shetty > Signed-off-by: SelvaKumar S > Signed-off-by: Kanchan Joshi > --- > block/ioctl.c | 33 +++++++++++++++++++++++++++++++++ > include/uapi/linux/fs.h | 8 ++++++++ > 2 files changed, 41 insertions(+) > > diff --git a/block/ioctl.c b/block/ioctl.c > index eb0491e90b9a..2af56d01e9fe 100644 > --- a/block/ioctl.c > +++ b/block/ioctl.c > @@ -143,6 +143,37 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, > GFP_KERNEL, flags); > } > > +static int blk_ioctl_copy(struct block_device *bdev, fmode_t mode, > + unsigned long arg) > +{ > + struct copy_range crange; > + struct range_entry *rlist; > + int ret; > + > + if (!(mode & FMODE_WRITE)) > + return -EBADF; > + > + if (copy_from_user(&crange, (void __user *)arg, sizeof(crange))) > + return -EFAULT; > + > + rlist = kmalloc_array(crange.nr_range, sizeof(*rlist), > + GFP_KERNEL); > + if (!rlist) > + return -ENOMEM; > + > + if (copy_from_user(rlist, (void __user *)crange.range_list, > + sizeof(*rlist) * crange.nr_range)) { > + ret = -EFAULT; > + goto out; > + } > + > + ret = blkdev_issue_copy(bdev, crange.nr_range, rlist, bdev, crange.dest, > + GFP_KERNEL, 0); > +out: > + kfree(rlist); > + return ret; > +} > + > static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, > unsigned long arg) > { > @@ -468,6 +499,8 @@ static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode, > case BLKSECDISCARD: > return blk_ioctl_discard(bdev, mode, arg, > BLKDEV_DISCARD_SECURE); > + case BLKCOPY: > + return blk_ioctl_copy(bdev, mode, arg); > case BLKZEROOUT: > return blk_ioctl_zeroout(bdev, mode, arg); > case BLKGETDISKSEQ: > diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h > index 7a97b588d892..4183688ff398 100644 > --- a/include/uapi/linux/fs.h > +++ b/include/uapi/linux/fs.h > @@ -76,6 +76,13 @@ struct range_entry { > __u64 len; > }; > > +struct copy_range { > + __u64 dest; > + __u64 nr_range; > + __u64 range_list; > + __u64 rsvd; If you have a "reserved" field, you HAVE to check that it is 0. If not, you can never use it in the future. Also, you can spell it out, we have lots of vowels :) thanks, greg k-h