From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 946E67F63 for ; Wed, 20 Feb 2013 09:07:51 -0600 (CST) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay3.corp.sgi.com (Postfix) with ESMTP id 2355BAC004 for ; Wed, 20 Feb 2013 07:07:47 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id ljinn1ISLleDbhKs for ; Wed, 20 Feb 2013 07:07:46 -0800 (PST) Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r1KF7kKC024509 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 20 Feb 2013 10:07:46 -0500 Received: from bfoster.bfoster (dhcp-189-135.bos.redhat.com [10.16.189.135]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r1KF7jYr007694 for ; Wed, 20 Feb 2013 10:07:46 -0500 From: Brian Foster Subject: [PATCH v4 2/6] xfs: push rounddown_pow_of_two() to after prealloc throttle Date: Wed, 20 Feb 2013 10:10:15 -0500 Message-Id: <1361373019-30891-3-git-send-email-bfoster@redhat.com> In-Reply-To: <1361373019-30891-1-git-send-email-bfoster@redhat.com> References: <1361373019-30891-1-git-send-email-bfoster@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com The round down occurs towards the beginning of the function. Push it down after throttling has occurred. This is to support adding further transformations to 'alloc_blocks' that might not preserve power-of-two alignment (and thus could lead to rounding down multiple times). Signed-off-by: Brian Foster Reviewed-by: Ben Myers --- fs/xfs/xfs_iomap.c | 19 +++++++++++++++++-- 1 files changed, 17 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index d914419..daa08f6 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -389,8 +389,15 @@ xfs_iomap_prealloc_size( if (!alloc_blocks) goto check_writeio; - alloc_blocks = XFS_FILEOFF_MIN(MAXEXTLEN, - rounddown_pow_of_two(alloc_blocks)); + /* + * MAXEXTLEN is not a power of two value but we round the prealloc down + * to the nearest power of two value after throttling. To prevent the + * round down from unconditionally reducing the maximum supported prealloc + * size, we round up first, apply appropriate throttling, round down and + * cap the value to MAXEXTLEN. + */ + alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN), + alloc_blocks); xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT); freesp = mp->m_sb.sb_fdblocks; @@ -407,6 +414,14 @@ xfs_iomap_prealloc_size( } if (shift) alloc_blocks >>= shift; + /* + * rounddown_pow_of_two() returns an undefined result if we pass in + * alloc_blocks = 0. + */ + if (alloc_blocks) + alloc_blocks = rounddown_pow_of_two(alloc_blocks); + if (alloc_blocks > MAXEXTLEN) + alloc_blocks = MAXEXTLEN; /* * If we are still trying to allocate more space than is -- 1.7.7.6 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs