From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp2130.oracle.com ([141.146.126.79]:48840 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751926AbeCWDzf (ORCPT ); Thu, 22 Mar 2018 23:55:35 -0400 Date: Thu, 22 Mar 2018 20:41:45 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH] xfs: always free inline data before resetting inode fork during ifree Message-ID: <20180323034145.GH4818@magnolia> References: <20171123060137.GL2135@magnolia> <20180323013037.GA9190@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180323013037.GA9190@wotan.suse.de> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Luis R. Rodriguez" Cc: xfs On Fri, Mar 23, 2018 at 01:30:37AM +0000, Luis R. Rodriguez wrote: > On Wed, Nov 22, 2017 at 10:01:37PM -0800, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > In xfs_ifree, we reset the data/attr forks to extents format without > > bothering to free any inline data buffer that might still be around > > after all the blocks have been truncated off the file. Prior to commit > > 43518812d2 ("xfs: remove support for inlining data/extents into the > > inode fork") nobody noticed because the leftover inline data after > > truncation was small enough to fit inside the inline buffer inside the > > fork itself. > > > > However, now that we've removed the inline buffer, we /always/ have to > > free the inline data buffer or else we leak them like crazy. This test > > was found by turning on kmemleak for generic/001 or generic/388. > > > > Signed-off-by: Darrick J. Wong > > --- > > fs/xfs/xfs_inode.c | 21 +++++++++++++++++++++ > > 1 file changed, 21 insertions(+) > > > > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > > index 61d1cb7..8012741 100644 > > --- a/fs/xfs/xfs_inode.c > > +++ b/fs/xfs/xfs_inode.c > > @@ -2401,6 +2401,24 @@ xfs_ifree_cluster( > > } > > > > /* > > + * Free any local-format buffers sitting around before we reset to > > + * extents format. > > + */ > > +static inline void > > +xfs_ifree_local_data( > > + struct xfs_inode *ip, > > + int whichfork) > > +{ > > + struct xfs_ifork *ifp; > > + > > + if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL) > > + return; > > I'm new to all this so this was a bit hard to follow. I'm confused with how > commit 43518812d2 ("xfs: remove support for inlining data/extents into the > inode fork") exacerbated the leak, isn't that commit about > XFS_DINODE_FMT_EXTENTS? Not specifically _EXTENTS, merely any fork (EXTENTS or LOCAL) whose incore data was small enough to fit in if_inline_ata. > Did we have cases where the format was XFS_DINODE_FMT_LOCAL and yet > ifp->if_u1.if_data == ifp->if_u2.if_inline_data ? An empty directory is 6 bytes, which is what you get with a fresh mkdir or after deleting everything in the directory. Prior to the 43518812d2 patch we could get away with not even checking if we had to free if_data when deleting a directory because it fit within if_inline_data. --D > Luis > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html