From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933193Ab1ESJPH (ORCPT ); Thu, 19 May 2011 05:15:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10562 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933032Ab1ESJKX (ORCPT ); Thu, 19 May 2011 05:10:23 -0400 From: Steven Whitehouse To: linux-kernel@vger.kernel.org, cluster-devel@redhat.com Cc: Benjamin Marzinski , Steven Whitehouse Subject: [PATCH 15/32] GFS2: make sure fallocate bytes is a multiple of blksize Date: Thu, 19 May 2011 09:47:10 +0100 Message-Id: <1305794847-3291-16-git-send-email-swhiteho@redhat.com> In-Reply-To: <1305794847-3291-1-git-send-email-swhiteho@redhat.com> References: <1305794847-3291-1-git-send-email-swhiteho@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Benjamin Marzinski The GFS2 fallocate code chooses a target size to for allocating chunks of space. Whenever it can't find any resource groups with enough space free, it halves its target. Since this target is in bytes, eventually it will no longer be a multiple of blksize. As long as there is more space available in the resource group than the target, this isn't a problem, since gfs2 will use the actual space available, which is always a multiple of blksize. However, when gfs couldn't fallocate a bigger chunk than the target, it was using the non-blksize aligned number. This caused a BUG in later code that required blksize aligned offsets. GFS2 now ensures that bytes is always a multiple of blksize Signed-off-by: Benjamin Marzinski Signed-off-by: Steven Whitehouse diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 23eab47..a9f5cbe 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -816,6 +816,7 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t bytes, max_bytes; struct gfs2_alloc *al; int error; + loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1); loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift; next = (next + 1) << sdp->sd_sb.sb_bsize_shift; @@ -823,13 +824,15 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset, if (mode & ~FALLOC_FL_KEEP_SIZE) return -EOPNOTSUPP; - offset = (offset >> sdp->sd_sb.sb_bsize_shift) << - sdp->sd_sb.sb_bsize_shift; + offset &= bsize_mask; len = next - offset; bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2; if (!bytes) bytes = UINT_MAX; + bytes &= bsize_mask; + if (bytes == 0) + bytes = sdp->sd_sb.sb_bsize; gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh); error = gfs2_glock_nq(&ip->i_gh); @@ -860,6 +863,9 @@ retry: if (error) { if (error == -ENOSPC && bytes > sdp->sd_sb.sb_bsize) { bytes >>= 1; + bytes &= bsize_mask; + if (bytes == 0) + bytes = sdp->sd_sb.sb_bsize; goto retry; } goto out_qunlock; -- 1.7.4