GFS2: Fix possible null pointer deref in gfs2_rs_alloc

Despite the return value from kmem_cache_zalloc() being checked, the
error wasn't being returned until after a possible null pointer
dereference. This patch returns the error immediately, allowing the
removal of the error variable.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 3cc402ce6fea6b3957e82646851e9646fa7cd26b..43d1a20bdbe4a8e9756ee578da0e020e5c8270a1 100644 (file)
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -553,7 +553,6 @@ void gfs2_free_clones(struct gfs2_rgrpd *rgd)
  */
 int gfs2_rs_alloc(struct gfs2_inode *ip)
 {
-       int error = 0;
        struct gfs2_blkreserv *res;
 
        if (ip->i_res)
@@ -561,7 +560,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)
 
        res = kmem_cache_zalloc(gfs2_rsrv_cachep, GFP_NOFS);
        if (!res)
-               error = -ENOMEM;
+               return -ENOMEM;
 
        RB_CLEAR_NODE(&res->rs_node);
 
@@ -571,7 +570,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)
        else
                ip->i_res = res;
        up_write(&ip->i_rw_mutex);
-       return error;
+       return 0;
 }
 
 static void dump_rs(struct seq_file *seq, const struct gfs2_blkreserv *rs)