gfs2: Silence possible null pointer dereference warning

Andreas Gruenbacher · Andreas Gruenbacher · commit bea906ee1624 · 2021-04-03T21:38:12.000+02:00
In gfs2_rbm_find, rs is always NULL when minext is NULL, so
gfs2_reservation_check_and_update will never be called on a NULL minext.
This isn't innediately obvious though, so also check for a NULL minext
for better code readability.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Andreas Gruenbacher &lt;agruenba@redhat.com&gt;
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
@@ -1783,7 +1783,7 @@ static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 *minext,
 			goto next_bitmap;
 		}
 		rbm->offset = offset;
-		if (!rs)
+		if (!rs || !minext)
 			return 0;
 
 		ret = gfs2_reservation_check_and_update(rbm, rs, *minext,

Original file line number	Diff line number	Diff line change
`@@ -1783,7 +1783,7 @@ static int gfs2_rbm_find(struct gfs2_rbm rbm, u8 state, u32 minext,`
`1783`	`1783`	`goto next_bitmap;`
`1784`	`1784`	`}`
`1785`	`1785`	`rbm->offset = offset;`
`1786`		`- if (!rs)`
	`1786`	`+ if (!rs \|\| !minext)`
`1787`	`1787`	`return 0;`
`1788`	`1788`
`1789`	`1789`	`ret = gfs2_reservation_check_and_update(rbm, rs, *minext,`