From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q8B5R6hg020767 for ; Tue, 11 Sep 2012 00:27:06 -0500 Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id yxDwd8szJv4moqnt for ; Mon, 10 Sep 2012 22:28:08 -0700 (PDT) Date: Tue, 11 Sep 2012 15:27:43 +1000 From: Dave Chinner Subject: Re: [PATCH v2 3/8] xfs: create helper to check whether to free eofblocks on inode Message-ID: <20120911052743.GB11511@dastard> References: <1347302246-52710-1-git-send-email-bfoster@redhat.com> <1347302246-52710-4-git-send-email-bfoster@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1347302246-52710-4-git-send-email-bfoster@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Brian Foster Cc: xfs@oss.sgi.com On Mon, Sep 10, 2012 at 02:37:21PM -0400, Brian Foster wrote: > This check is used in multiple places to determine whether we > should check for (and potentially free) post EOF blocks on an > inode. Add a helper to consolidate the check. > > Note that when we remove an inode from the cache (xfs_inactive()), > we are required to trim post-EOF blocks even if the inode is marked > preallocated or append-only to maintain correct space accounting. > The 'force' parameter to xfs_can_free_eofblocks() specifies whether > we should ignore the prealloc/append-only status of the inode. > > Signed-off-by: Brian Foster Just quickly, I'd rewrite this convoluted logic: > +/* > + * Test whether it is appropriate to check an inode for and free post EOF > + * blocks. The 'force' parameter determines whether we should also consider > + * regular files that are marked preallocated or append-only. > + */ > +static inline bool > +xfs_can_free_eofblocks(struct xfs_inode *ip, bool force) > +{ > + if (S_ISREG(ip->i_d.di_mode) && > + (VFS_I(ip)->i_size > 0 || > + (VN_CACHED(VFS_I(ip)) > 0 || ip->i_delayed_blks > 0)) && > + (ip->i_df.if_flags & XFS_IFEXTENTS) && > + (!(ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) || > + (force && ip->i_delayed_blks != 0))) > + return true; > + > + return false; > +} in a manner that can means it no longer has to be analysed from first principles every time it is read. e.g.: static inline bool xfs_can_free_eofblocks(struct xfs_inode *ip, bool force) { /* prealloc/delalloc exists only on regular files */ if (!S_ISREG(ip->i_d.di_mode)) return false; /* * Zero sized files with no cached page or delalloc blocks will not have * any speculative prealloc/delalloc to remove. */ if (VFS_I(ip)->i_size == 0 && VFS_I(ip)->i_mapping->nr_pages == 0 && ip->i_delayed_blks == 0) return false; /* If we haven't read in the extent list, then don't do it now. */ if (!(ip->i_df.if_flags & XFS_IFEXTENTS)) return false; /* * Real preallocation or append only files do not get EOF blocks freed * unless there are also delalloc blocks and we are forced to remove * them. */ if ((ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) { if (!ip->i_delayed_blks) return false; if (!force) return false; } return true; } -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs