GFS2: Get a block reservation before resizing a file

This patch allocates a block reservation structure before growing
or shrinking a file. Without this structure, the grow or shink code
can reference the bad pointer.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index d29d7793b211..df686d13a7d2 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1288,6 +1288,10 @@ int gfs2_setattr_size(struct inode *inode, u64 newsize)
 
         inode_dio_wait(inode);
 
+        ret = gfs2_rs_alloc(GFS2_I(inode));
+        if (ret)
+                return ret;
+
         oldsize = inode->i_size;
         if (newsize >= oldsize)
                 return do_grow(inode, newsize);