From owner-freebsd-hackers Mon Apr 8 08:34:29 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id IAA03963 for hackers-outgoing; Mon, 8 Apr 1996 08:34:29 -0700 (PDT) Received: from hda.com (ip54-max1-fitch.zipnet.net [199.232.245.54]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id IAA03945 for ; Mon, 8 Apr 1996 08:34:23 -0700 (PDT) Received: (from dufault@localhost) by hda.com (8.6.11/8.6.9) id LAA29919 for hackers@freebsd.org; Mon, 8 Apr 1996 11:16:14 -0400 From: Peter Dufault Message-Id: <199604081516.LAA29919@hda.com> Subject: POSIX O_SYNC versus our O_FSYNC To: hackers@freebsd.org Date: Mon, 8 Apr 1996 11:16:14 -0400 (EDT) Reply-to: hdalog@zipnet.net X-Mailer: ELM [version 2.4 PL24] Content-Type: text Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk We're porting a commercial package that uses the POSIX O_SYNC flag in open. We don't have that - we have the undocumented O_FSYNC. Can someone in the know comment on the O_?SYNC flags? POSIX defines the flags O_DSYNC, O_RSYNC and O_SYNC: O_DSYNC is data integrity, that is, a transfer is complete when the data and anything you need to consider it finished is safely transferred. This excludes items like file access times but includes items like file sizes. O_RSYNC is read sync, and seems to only imply that you'll read whatever another process last wrote (assuming they wrote it using either O_DSYNC or O_SYNC). O_SYNC is file system integrity, and is DSYNC plus file access times etc. Does our O_FSYNC correspond to either O_SYNC or O_DSYNC? Is O_RSYNC a NOP for UFS? -- Temporarily via "hdalog@zipnet.net"... Peter Dufault Real-Time Machine Control and Simulation HD Associates, Inc. Voice: 508 433 6936 dufault@hda.com Fax: 508 433 5267