From 44f52122a22004de9c3bae288bbc6dff3624fe9c Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Wed, 6 Jul 2016 10:36:43 -0500 Subject: [PATCH] GFS2: Check rs_free with rd_rsspin protection For the last process to close a file opened for write, function gfs2_rsqa_delete was deleting the file's inode's block reservation out of the rgrp reservations tree. Then it was checking to make sure rs_free was 0, but it was performing the check outside the protection of rd_rsspin spin_lock. The rd_rsspin spin_lock protection is needed to prevent a race between the process freeing the reservation and another who is allocating a new set of blocks inside the same rgrp for the same inode, thus changing its value. Signed-off-by: Bob Peterson --- fs/gfs2/rgrp.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index fba38ca94135..86ccc0159393 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -658,6 +658,7 @@ void gfs2_rs_deltree(struct gfs2_blkreserv *rs) if (rgd) { spin_lock(&rgd->rd_rsspin); __rs_deltree(rs); + BUG_ON(rs->rs_free); spin_unlock(&rgd->rd_rsspin); } } @@ -671,10 +672,8 @@ void gfs2_rs_deltree(struct gfs2_blkreserv *rs) void gfs2_rsqa_delete(struct gfs2_inode *ip, atomic_t *wcount) { down_write(&ip->i_rw_mutex); - if ((wcount == NULL) || (atomic_read(wcount) <= 1)) { + if ((wcount == NULL) || (atomic_read(wcount) <= 1)) gfs2_rs_deltree(&ip->i_res); - BUG_ON(ip->i_res.rs_free); - } up_write(&ip->i_rw_mutex); gfs2_qa_delete(ip, wcount); } -- 2.20.1