[Cluster-devel] [PATCH 05/16] gfs2: handle NULL rgd in set_rgrp_preferences
Bob Peterson
rpeterso at redhat.com
Thu Jun 25 17:42:28 UTC 2015
From: Abhi Das <adas at redhat.com>
The function set_rgrp_preferences() does not handle the (rarely
returned) NULL value from gfs2_rgrpd_get_next() and this patch
fixes that.
The fs image in question is only 150MB in size which allows for
only 1 rgrp to be created. The in-memory rb tree has only 1 node
and when gfs2_rgrpd_get_next() is called on this sole rgrp, it
returns NULL. (Default behavior is to wrap around the rb tree and
return the first node to give the illusion of a circular linked
list. In the case of only 1 rgrp, we can't have
gfs2_rgrpd_get_next() return the same rgrp (first, last, next all
point to the same rgrp)... that would cause unintended consequences
and infinite loops.)
Signed-off-by: Abhi Das <adas at redhat.com>
Signed-off-by: Bob Peterson <rpeterso at redhat.com>
---
fs/gfs2/rgrp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index cb27065..900e515 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -978,10 +978,10 @@ static void set_rgrp_preferences(struct gfs2_sbd *sdp)
rgd->rd_flags |= GFS2_RDF_PREFERRED;
for (i = 0; i < sdp->sd_journals; i++) {
rgd = gfs2_rgrpd_get_next(rgd);
- if (rgd == first)
+ if (!rgd || rgd == first)
break;
}
- } while (rgd != first);
+ } while (rgd && rgd != first);
}
/**
--
2.1.0
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