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authorBob Peterson <rpeterso@redhat.com>2016-07-06 10:36:43 -0500
committerBob Peterson <rpeterso@redhat.com>2016-07-12 11:48:22 -0500
commit44f52122a22004de9c3bae288bbc6dff3624fe9c (patch)
treedf0c36e3d387d2cd46b74c0f1228bc3da6fcad4e /fs/gfs2
parentfd4c5748b8d3f7420e8932ed0bde3d53cc8acc9d (diff)
downloadlinux-44f52122a22004de9c3bae288bbc6dff3624fe9c.tar.gz
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 <rpeterso@redhat.com>
Diffstat (limited to 'fs/gfs2')
-rw-r--r--fs/gfs2/rgrp.c5
1 files 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);
 }