[Cluster-devel] [PATCH 1/7] [GFS2] Fix a size calculation error

[Cluster-devel] [PATCH 1/7] [GFS2] Fix a size calculation error

[Steven Whitehouse]

From 52ae7b7935a079aaba25da98fe90772d04109f26 Mon Sep 17 00:00:00 2001
From: Russell Cattelan <cattelan@redhat.com>
Date: Mon, 9 Oct 2006 12:11:54 -0500
Subject: [GFS2] Fix a size calculation error

Fix a size calculation error.
The size was incorrect being computed as a
negative length and then being passed to an
unsigned parameter.

This in turn would cause the allocator to
think it needed enough meta data to store
a gigabyte file for every file created.

Signed-off-by: Russell Cattelan <cattelan@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
---
 fs/gfs2/ops_address.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 4fb743f..bdf56cf 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -370,15 +370,17 @@ static int gfs2_prepare_write(struct fil
 	loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
 	loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
 	struct gfs2_alloc *al;
+	unsigned int write_len = to - from;
+
 
 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|GL_AOP, &ip->i_gh);
 	error = gfs2_glock_nq_m_atime(1, &ip->i_gh);
 	if (error)
 		goto out_uninit;
 
-	gfs2_write_calc_reserv(ip, to - from, &data_blocks, &ind_blocks);
+	gfs2_write_calc_reserv(ip, write_len, &data_blocks, &ind_blocks);
 
-	error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required);
+	error = gfs2_write_alloc_required(ip, pos, write_len, &alloc_required);
 	if (error)
 		goto out_unlock;
 
-- 
1.4.1