From owner-freebsd-current@freebsd.org Fri Jul 5 15:35:01 2019 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5AFA115CDE89 for ; Fri, 5 Jul 2019 15:35:01 +0000 (UTC) (envelope-from asomers@gmail.com) Received: from mail-lj1-f178.google.com (mail-lj1-f178.google.com [209.85.208.178]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 5CD1974BE3; Fri, 5 Jul 2019 15:35:00 +0000 (UTC) (envelope-from asomers@gmail.com) Received: by mail-lj1-f178.google.com with SMTP id x25so2913622ljh.2; Fri, 05 Jul 2019 08:35:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=oepyiW1cdsyFQB3dNNlQhfmSQrdCaSK/WRHL/FFzHc8=; b=M46OFuh5xXsTYf0WoL6DdBmZ+lhmA9du35YbD6ssrmsJxv6rNphnejXtvlKnru/gxJ HhHe5/nguzIT30w4ODGk5ijdiOUZ0ErrpB8Qvh7P78rUnB+7le2HdUonnOC3PNxkZDgA 6Ty62I2UsAilnJ5GwmUXYr+dNa7h3To+onVjXeJTbmQ1BqUkIrslwQpW3sAJZEoHu9w1 9NvNNFDSIikpY4MGpwrsWueUCJrU1bmsho1cdf7pWu6Rw6W5haCMGNZWDbTEvElbxdck sRChRnA2Cyn5bBKi0AuGzWNZ/sCfrcg/G6wu/OndsIn6af+avzzjwU3zYXbR7YEOKfre OnkQ== X-Gm-Message-State: APjAAAUVBvXGktLk2s8PNkl/j3AY0svLtpDsH1a571GlYO3nSYcseYv4 hPuBmiyGSDtw5iFjoUgF2JsjzcgjtDJpGkRsIclknA== X-Google-Smtp-Source: APXvYqzjDhLdQ7z+sV92ZD1K0QTZbHDm3L6BimErQZJ3Os/MyNMFZSwNAXo5+JqVDI78nZNc2FvYNea588lqqzX++4M= X-Received: by 2002:a2e:2c07:: with SMTP id s7mr2407166ljs.44.1562336794169; Fri, 05 Jul 2019 07:26:34 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Alan Somers Date: Fri, 5 Jul 2019 08:26:22 -0600 Message-ID: Subject: Re: should a copy_file_range(2) syscall be interrupted via a signal To: Rick Macklem Cc: "freebsd-current@FreeBSD.org" , "kib@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 5CD1974BE3 X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of asomers@gmail.com designates 209.85.208.178 as permitted sender) smtp.mailfrom=asomers@gmail.com X-Spamd-Result: default: False [-3.85 / 15.00]; ARC_NA(0.00)[]; TO_DN_EQ_ADDR_SOME(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; DMARC_NA(0.00)[freebsd.org]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; NEURAL_HAM_SHORT(-0.56)[-0.562,0]; RCVD_IN_DNSWL_NONE(0.00)[178.208.85.209.list.dnswl.org : 127.0.5.0]; IP_SCORE(-1.28)[ip: (-0.50), ipnet: 209.85.128.0/17(-3.46), asn: 15169(-2.40), country: US(-0.06)]; FORGED_SENDER(0.30)[asomers@freebsd.org,asomers@gmail.com]; MIME_TRACE(0.00)[0:+]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[asomers@freebsd.org,asomers@gmail.com]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Jul 2019 15:35:01 -0000 On Thu, Jul 4, 2019 at 6:29 PM Rick Macklem wrote: > > Hi, > > I have been working on a Linux compatible copy_file_range(2) syscall > (the current code can be found at https://reviews.freebsd.org/D20584). > > One outstanding issue is how it should deal with signals. > Right now, I have vn_start_write() without PCATCH, so that it won't be > interrupted by a signal, but I notice that vn_write() {ie. write syscall } does > have PCATCH on vn_start_write() and so does vn_rdwr() when it is called > without IO_NODELOCKED. > > I am thinking that copy_file_range(2) should do this also. > However, if it returns an error, it is impossible for the caller to know how much > of the data range got copied. > > What do you think the copy_file_range(2) code should do? > > Thanks, rick > ps: I've used FreeBSD-current@ this time, to see if I get more replies than I > did using FreeBSD-fs@. I though copy_file_range(2) is allowed to return short. Why can't it do that if it gets interrupted?