From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q2DK3lcM058714 for ; Tue, 13 Mar 2012 15:03:47 -0500 Date: Tue, 13 Mar 2012 15:03:54 -0500 From: Ben Myers Subject: Re: [PATCH 4/5] xfs: remove the per-filesystem list of dquots Message-ID: <20120313200354.GI7762@sgi.com> References: <20120313085232.134690907@bombadil.infradead.org> <20120313085308.997632929@bombadil.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120313085308.997632929@bombadil.infradead.org> 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: Christoph Hellwig Cc: xfs@oss.sgi.com Hey Christoph, On Tue, Mar 13, 2012 at 04:52:36AM -0400, Christoph Hellwig wrote: > Instead of keeping a separate per-filesystem list of dquots we can walk > the radix tree for the two places where we need to iterate all quota > structures. > > Reviewed-by: Dave Chinner > Signed-off-by: Christoph Hellwig > > --- > fs/xfs/xfs_dquot.c | 37 ++---- > fs/xfs/xfs_dquot.h | 3 > fs/xfs/xfs_qm.c | 283 +++++++++++++++++++++++------------------------------ > fs/xfs/xfs_qm.h | 4 > 4 files changed, 142 insertions(+), 185 deletions(-) > > V2: remove the useless flags/type argument to the iterator callbacks > ... > Index: xfs/fs/xfs/xfs_qm.c > =================================================================== > --- xfs.orig/fs/xfs/xfs_qm.c 2012-03-13 09:37:53.236788274 +0100 > +++ xfs/fs/xfs/xfs_qm.c 2012-03-13 09:39:32.823456788 +0100 > @@ -169,6 +169,196 @@ xfs_qm_rele_quotafs_ref( > } > > /* > + * We use the batch lookup interface to iterate over the dquots as it > + * currently is the only interface into the radix tree code that allows > + * fuzzy lookups instead of exact matches. Holding the lock over multiple > + * operations is fine as all callers are used either during mount/umount > + * or quotaoff. > + */ > +#define XFS_DQ_LOOKUP_BATCH 32 > + > +STATIC int > +xfs_qm_dquot_walk( > + struct xfs_mount *mp, > + int type, > + int (*execute)(struct xfs_dquot *dqp)) > +{ > + struct xfs_quotainfo *qi = mp->m_quotainfo; > + struct radix_tree_root *tree = XFS_DQUOT_TREE(qi, type); > + uint32_t next_index; > + int last_error = 0; > + int skipped; > + int nr_found; > + > +restart: > + skipped = 0; > + next_index = 0; > + nr_found = 0; > + > + while (1) { > + struct xfs_dquot *batch[XFS_DQ_LOOKUP_BATCH]; Eesh.. that probably doesn't need to go onto the stack. I know we are doing it elsewhere too, and that we also sometimes complain about other peoples' stack usage. Don't necessarily have to clean it up now, though. ;) > + int error = 0; > + int i; > + > + mutex_lock(&qi->qi_tree_lock); > + nr_found = radix_tree_gang_lookup(tree, (void **)batch, > + next_index, XFS_DQ_LOOKUP_BATCH); > + if (!nr_found) { > + mutex_unlock(&qi->qi_tree_lock); > + break; > + } > + > + for (i = 0; i < nr_found; i++) { > + struct xfs_dquot *dqp = batch[i]; > + > + next_index = be32_to_cpu(dqp->q_core.d_id) + 1; > + > + error = execute(batch[i]); > + if (error == EAGAIN) { > + skipped++; > + continue; > + } > + if (error && last_error != EFSCORRUPTED) > + last_error = error; > + } > + > + mutex_unlock(&qi->qi_tree_lock); > + > + /* bail out if the filesystem is corrupted. */ > + if (error == EFSCORRUPTED) { last_error Error can be overwritten in the nr_found loop above. I think last_error is what you want. > + skipped = 0; > + break; > + } > + } > + > + if (skipped) { > + delay(1); > + goto restart; > + } > + > + return last_error; > +} ... > +/* > + * Purge the dquot cache. > + */ > +int > +xfs_qm_dqpurge_all( > + struct xfs_mount *mp, > + uint flags) > +{ > + int error = 0, error2; > + > + if (flags & XFS_QMOPT_UQUOTA) > + error = xfs_qm_dquot_walk(mp, XFS_DQ_USER, xfs_qm_dqpurge); > + if (flags & XFS_QMOPT_GQUOTA) { > + error2 = xfs_qm_dquot_walk(mp, XFS_DQ_GROUP, xfs_qm_dqpurge); > + if (!error) > + error = error2; > + } > + if (flags & XFS_QMOPT_PQUOTA) { > + error2 = xfs_qm_dquot_walk(mp, XFS_DQ_PROJ, xfs_qm_dqpurge); > + if (!error) > + error = error2; > + } > + return error; > +} One caller of this function, xfs_qm_scall_quotaoff, treats the return value not as an error, but as a counter of the number of dquots left to purge. If you really do have an error in here, we probably don't want to loop. If we do, lets make it clearer that we're checking for an error and not a count. Regards, Ben _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs