Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933817AbaKLBgZ (ORCPT ); Tue, 11 Nov 2014 20:36:25 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:59786 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933798AbaKLBgU (ORCPT ); Tue, 11 Nov 2014 20:36:20 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Chinner , Brian Foster , Dave Chinner Subject: [PATCH 3.17 315/319] xfs: bulkstat chunk-formatter has issues Date: Wed, 12 Nov 2014 10:17:33 +0900 Message-Id: <20141112011044.996795542@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141112010952.553519040@linuxfoundation.org> References: <20141112010952.553519040@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Chinner commit 2b831ac6bc87d3cbcbb1a8816827b6923403e461 upstream. The loop construct has issues: - clustidx is completely unused, so remove it. - the loop tries to be smart by terminating when the "freecount" tells it that all inodes are free. Just drop it as in most cases we have to scan all inodes in the chunk anyway. - move the "user buffer left" condition check to the only point where we consume space int eh user buffer. - move the initialisation of agino out of the loop, leaving just a simple loop control logic using the clusteridx. Also, double handling of the user buffer variables leads to problems tracking the current state - use the cursor variables directly rather than keeping local copies and then having to update the cursor before returning. Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Signed-off-by: Dave Chinner Signed-off-by: Greg Kroah-Hartman --- fs/xfs/xfs_itable.c | 58 +++++++++++++++++++++------------------------------- 1 file changed, 24 insertions(+), 34 deletions(-) --- a/fs/xfs/xfs_itable.c +++ b/fs/xfs/xfs_itable.c @@ -283,59 +283,49 @@ xfs_bulkstat_ag_ichunk( xfs_ino_t *lastino) { char __user **ubufp = acp->ac_ubuffer; - int ubleft = acp->ac_ubleft; - int ubelem = acp->ac_ubelem; - int chunkidx, clustidx; + int chunkidx; int error = 0; xfs_agino_t agino; - for (agino = irbp->ir_startino, chunkidx = clustidx = 0; - XFS_BULKSTAT_UBLEFT(ubleft) && - irbp->ir_freecount < XFS_INODES_PER_CHUNK; - chunkidx++, clustidx++, agino++) { - int fmterror; /* bulkstat formatter result */ + agino = irbp->ir_startino; + for (chunkidx = 0; chunkidx < XFS_INODES_PER_CHUNK; + chunkidx++, agino++) { + int fmterror; int ubused; xfs_ino_t ino = XFS_AGINO_TO_INO(mp, agno, agino); - ASSERT(chunkidx < XFS_INODES_PER_CHUNK); - /* Skip if this inode is free */ if (XFS_INOBT_MASK(chunkidx) & irbp->ir_free) { *lastino = ino; continue; } - /* - * Count used inodes as free so we can tell when the - * chunk is used up. - */ - irbp->ir_freecount++; - /* Get the inode and fill in a single buffer */ ubused = statstruct_size; - error = formatter(mp, ino, *ubufp, ubleft, &ubused, &fmterror); - if (fmterror == BULKSTAT_RV_NOTHING) { - if (error && error != -ENOENT && error != -EINVAL) { - ubleft = 0; - break; - } - *lastino = ino; - continue; - } - if (fmterror == BULKSTAT_RV_GIVEUP) { - ubleft = 0; + error = formatter(mp, ino, *ubufp, acp->ac_ubleft, + &ubused, &fmterror); + if (fmterror == BULKSTAT_RV_GIVEUP || + (error && error != -ENOENT && error != -EINVAL)) { + acp->ac_ubleft = 0; ASSERT(error); break; } - if (*ubufp) - *ubufp += ubused; - ubleft -= ubused; - ubelem++; + + /* be careful not to leak error if at end of chunk */ + if (fmterror == BULKSTAT_RV_NOTHING || error) { + *lastino = ino; + error = 0; + continue; + } + + *ubufp += ubused; + acp->ac_ubleft -= ubused; + acp->ac_ubelem++; *lastino = ino; - } - acp->ac_ubleft = ubleft; - acp->ac_ubelem = ubelem; + if (acp->ac_ubleft < statstruct_size) + break; + } return error; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/