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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 07B70C4338F for ; Tue, 17 Aug 2021 23:36:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3D2A61019 for ; Tue, 17 Aug 2021 23:36:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234888AbhHQXgr (ORCPT ); Tue, 17 Aug 2021 19:36:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:57032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229466AbhHQXgr (ORCPT ); Tue, 17 Aug 2021 19:36:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9036E60E90; Tue, 17 Aug 2021 23:36:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629243373; bh=YImFQxp4ILDBTqZQU31tKgO8bK+k2HxXB7JOGFKP4Gc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=omK90A3T8XJujJMDRbmXYqY41V7Z5Smu+iajlzLNTGNAe0Pylo90IIWcA67KAG2Di UrCoNuutG/DYaMawZyEg5mEZMhZlbrUVgPf3SXRZjQQIfmdXkJGV0S92Ku1grPNY+s kbU83VwwWq9h6mtJqp5qoDTAlG/gPuqVyMVnkPxGF+oLqJ7+l8egW6ZOdc38yGhfKq AC+CR1kY4QrB60HWTC4IymQgUaRREkvAc6EtIr8PXtK3uY74JBf25KOBLIbpxGX3xQ rS+o7TrRw5Vx+wAmEaVF2YR0e7UkeLiaBLJL4UMXdjdSpFzZUK1SxqxQOxFf1ztlTT Iq0YwDlgRd4Nw== Date: Tue, 17 Aug 2021 16:36:13 -0700 From: "Darrick J. Wong" 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, 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: <20210817233613.GA12597@magnolia> 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; If the maximum number of elements in the range list is 1<<12, there's no need for this to be larger than a u16, right? > + __u64 range_list; Pointers embedded in a structure are /not/ a good idea, because this will create a lot of compatibility headaches for 32-bit binaries running on 64-bit kernels. Please just make the size of this header structure a multiple of 8 bytes and put the range_entry list immediately after it. struct copy_range { __s64 dest_offset; __u32 nr_range_entries; __u32 flags; __u64 reserved[2]; }; struct __user range_entry *re = ((struct range_entry *)(copyhead + 1)); copy_from_user(&urk, re...); --D > + __u64 rsvd; > +}; > + > /* extent-same (dedupe) ioctls; these MUST match the btrfs ioctl definitions */ > #define FILE_DEDUPE_RANGE_SAME 0 > #define FILE_DEDUPE_RANGE_DIFFERS 1 > @@ -197,6 +204,7 @@ struct fsxattr { > #define BLKROTATIONAL _IO(0x12,126) > #define BLKZEROOUT _IO(0x12,127) > #define BLKGETDISKSEQ _IOR(0x12,128,__u64) > +#define BLKCOPY _IOWR(0x12, 129, struct copy_range) > /* > * A jump here: 130-136 are reserved for zoned block devices > * (see uapi/linux/blkzoned.h) > -- > 2.25.1 >