From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Altaparmakov Subject: Re: fishy ->put_inode usage in ntfs Date: Thu, 10 Feb 2005 14:50:02 +0000 Message-ID: <1108047002.12000.19.camel@imp.csi.cam.ac.uk> References: <20041014112607.GA24508@lst.de> <1097757569.21275.40.camel@imp.csi.cam.ac.uk> <20041014125933.GA26021@lst.de> <1097760404.21275.52.camel@imp.csi.cam.ac.uk> <20050210104719.GA2771@lst.de> <1108046439.12000.9.camel@imp.csi.cam.ac.uk> <20050210144254.GA7222@lst.de> <1108046906.12000.16.camel@imp.csi.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: ntfs-dev , fsdevel Received: from ppsw-3.csi.cam.ac.uk ([131.111.8.133]:4236 "EHLO ppsw-3.csi.cam.ac.uk") by vger.kernel.org with ESMTP id S262126AbVBJOuS (ORCPT ); Thu, 10 Feb 2005 09:50:18 -0500 To: Christoph Hellwig In-Reply-To: <1108046906.12000.16.camel@imp.csi.cam.ac.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, 2005-02-10 at 14:48 +0000, Anton Altaparmakov wrote: > On Thu, 2005-02-10 at 15:42 +0100, Christoph Hellwig wrote: > > On Thu, Feb 10, 2005 at 02:40:39PM +0000, Anton Altaparmakov wrote: > > > I am not sure what you mean. The VFS layer does reference counting on > > > inodes. I have no choice in the matter. > > > > > > > Can someone ever grab a reference separate from it's master inode? > > > > > > Again, not sure what you mean. Could you elaborate? > > > > ntfs_read_locked_attr_inode() does igrab on the 'parent' inode > > currently. What do you need this for exactly - the attr inode > > goes away anyway when clear_inode is called on that 'parent' inode > > (in my scheme). > > If the igrab() were not done, it would be possible for clear_inode to be > called on the 'parent' inode whilst at the same time one or more attr > inodes (belonging to this 'parent') are in use and Bad Things(TM) would > happen... The igrab() effectively guarantees that iput() is called on all attr inodes before clear_inode on the 'parent' can be invoked. Best regards, Anton -- Anton Altaparmakov (replace at with @) Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/