From unknown Sun Jun 22 08:10:04 2025 X-Loop: help-debbugs@gnu.org Subject: bug#7421: [Feature request]: add option to dd to issue ioctl(BLKFLSBUF) on output descriptior after each write or at the end Resent-From: =?UTF-8?Q?=D0=9C=D0=B0=D1=80=D0=BA_?= =?UTF-8?Q?=D0=9A=D0=BE=D1=80=D0=B5=D0=BD=D0=B1=D0=B5=D1=80=D0=B3?= Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-coreutils@gnu.org Resent-Date: Wed, 17 Nov 2010 11:47:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: report 7421 X-GNU-PR-Package: coreutils X-GNU-PR-Keywords: To: 7421@debbugs.gnu.org X-Debbugs-Original-To: bug-coreutils@gnu.org Received: via spool by submit@debbugs.gnu.org id=B.128999436620355 (code B ref -1); Wed, 17 Nov 2010 11:47:02 +0000 Received: (at submit) by debbugs.gnu.org; 17 Nov 2010 11:46:06 +0000 Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1PIgSi-0005IF-1M for submit@debbugs.gnu.org; Wed, 17 Nov 2010 06:46:04 -0500 Received: from eggs.gnu.org ([140.186.70.92]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1PIfND-0004mM-Pa for submit@debbugs.gnu.org; Wed, 17 Nov 2010 05:36:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PIfS4-0001wS-Tc for submit@debbugs.gnu.org; Wed, 17 Nov 2010 05:41:21 -0500 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on eggs.gnu.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,T_DKIM_INVALID,T_TO_NO_BRKTS_FREEMAIL autolearn=unavailable version=3.3.1 Received: from lists.gnu.org ([199.232.76.165]:33656) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PIfS4-0001wN-Rd for submit@debbugs.gnu.org; Wed, 17 Nov 2010 05:41:20 -0500 Received: from [140.186.70.92] (port=39434 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PIfS3-00009e-Ew for bug-coreutils@gnu.org; Wed, 17 Nov 2010 05:41:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PIfS2-0001vg-G5 for bug-coreutils@gnu.org; Wed, 17 Nov 2010 05:41:19 -0500 Received: from mail-bw0-f41.google.com ([209.85.214.41]:50798) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PIfS2-0001vZ-9m for bug-coreutils@gnu.org; Wed, 17 Nov 2010 05:41:18 -0500 Received: by bwz16 with SMTP id 16so1452228bwz.0 for ; Wed, 17 Nov 2010 02:41:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:date:message-id :subject:from:to:content-type; bh=oPiFG7JAaGd+7+8Oz21LgNuDC3GaJmKw4lQ34t4RpvY=; b=DWvFj+8DAnCyi9XK7FRJfM1+8K6Ivl640gC9ntxNYFp6HB7E1qawYX2gXb9pqr3rx6 z3YDGZ+2jfPSSNXPwxqg8jLeY2crOfCGQiWXACMugynlHX7KSVKLFqQRtTL0X/ZfPy2P fEbP+rRPTy0sFGqvWW+qpWLcNVQT4ssv1Qpy0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=HbCwisBVWMWn0vFtkMXjb81VksZy47XcHg4YVNfMf5FfmiTvy0XNI2STPwG6b4wFZi MfRcLsa1pyq8X0kwebFviVyiW0l2BUueCiEX7hWwIuLHi49UEWbGT6tlR1YpmEsfEtXU 5trRQ2si1rlRD117Zp2FGgxgcMcH5vtiRNTfM= MIME-Version: 1.0 Received: by 10.204.117.134 with SMTP id r6mr9060177bkq.142.1289990477141; Wed, 17 Nov 2010 02:41:17 -0800 (PST) Received: by 10.204.53.197 with HTTP; Wed, 17 Nov 2010 02:41:17 -0800 (PST) Date: Wed, 17 Nov 2010 15:41:17 +0500 Message-ID: From: =?UTF-8?Q?=D0=9C=D0=B0=D1=80=D0=BA_?= =?UTF-8?Q?=D0=9A=D0=BE=D1=80=D0=B5=D0=BD=D0=B1=D0=B5=D1=80=D0=B3?= Content-Type: text/plain; charset=UTF-8 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Spam-Score: -5.9 (-----) X-Mailman-Approved-At: Wed, 17 Nov 2010 06:46:00 -0500 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: debbugs-submit-bounces@debbugs.gnu.org Errors-To: debbugs-submit-bounces@debbugs.gnu.org X-Spam-Score: -5.9 (-----) [Feature request]: add option to dd to issue ioctl(BLKFLSBUF) on output descriptior after each write or at the end I already has sent a message about fsync/fdatasync after each write. It seems that ioctl(BLKFLSBUF) need be implemented in same semantics. in oflags and conv i.e. ioctl after each write oflags=blkflsbuf and ioctl at the end, if specified in conv=blkflsbuf -- Segmentation fault From unknown Sun Jun 22 08:10:04 2025 X-Loop: help-debbugs@gnu.org Subject: bug#7421: [Feature request]: add option to dd to issue ioctl(BLKFLSBUF) on output descriptior after each write or at the end Resent-From: =?UTF-8?Q?P=C3=A1draig?= Brady Original-Sender: "Debbugs-submit" Resent-CC: bug-coreutils@gnu.org Resent-Date: Sun, 25 Jan 2015 18:43:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 7421 X-GNU-PR-Package: coreutils X-GNU-PR-Keywords: To: =?UTF-8?Q?=D0=9C=D0=B0=D1=80=D0=BA_?= =?UTF-8?Q?=D0=9A=D0=BE=D1=80=D0=B5=D0=BD=D0=B1=D0=B5=D1=80=D0=B3?= , 7421@debbugs.gnu.org Received: via spool by 7421-submit@debbugs.gnu.org id=B7421.14222113239432 (code B ref 7421); Sun, 25 Jan 2015 18:43:02 +0000 Received: (at 7421) by debbugs.gnu.org; 25 Jan 2015 18:42:03 +0000 Received: from localhost ([127.0.0.1]:56204 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1YFS8I-0002Rp-8j for submit@debbugs.gnu.org; Sun, 25 Jan 2015 13:42:02 -0500 Received: from mail1.vodafone.ie ([213.233.128.43]:46675) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1YFS8E-0002R8-Lw; Sun, 25 Jan 2015 13:41:59 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqgJAKU3xVRtTk7f/2dsb2JhbABagwZSVIMFwzWFcgECAoEPQwEBAQEBfYQNAQUjDwFWCQINCwICBRYEBwICCQMCAQIBRQYBDAgBAYgsAQOhBpxshWmOGgELIIEhjl6CaIFBBZI5hyGEf4V/hXMigjKBPD6BMweBOQEBAQ Received: from unknown (HELO localhost.localdomain) ([109.78.78.223]) by mail1.vodafone.ie with ESMTP; 25 Jan 2015 18:41:52 +0000 Message-ID: <54C538F0.8030804@draigBrady.com> Date: Sun, 25 Jan 2015 18:41:52 +0000 From: =?UTF-8?Q?P=C3=A1draig?= Brady User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Spam-Score: 0.0 (/) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: 0.0 (/) unarchive 7421 tag 7421 wontfix close 7421 stop On 17/11/10 10:41, Марк Коренберг wrote: > [Feature request]: add option to dd to issue ioctl(BLKFLSBUF) on > output descriptior after each write or at the end > > I already has sent a message about fsync/fdatasync after each write. > It seems that ioctl(BLKFLSBUF) need be implemented in same semantics. > > in oflags and conv > i.e. ioctl after each write oflags=blkflsbuf > and ioctl at the end, if specified in conv=blkflsbuf This is already supported with the `blockdev --flushbufs` command. Given this is a low level linux specific interface, it's more suited to the blockdev command than a more general tool like dd. Note ioctl(BLKFLSBUF) only writes out dirty pages to the block device, it doesn't guarantee to send a flush request to the device. Also http://lwn.net/Articles/433384/ mentions that BLKFLSBUF also invalidates the bdev mapping, which isn't generally desirable, and doesn't work for non-block file systems. We're considering adding syncfs() support to the sync command which should cater for much of the use case you describe here: That's discussed at http://bugs.gnu.org/19681 thanks, Pádraig.