From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bob Peterson Date: Tue, 28 Aug 2012 08:45:56 -0400 (EDT) Subject: [Cluster-devel] [GFS2 PATCH] GFS2: Stop block extents at the end of bitmaps In-Reply-To: <593383397.4340210.1346157882093.JavaMail.root@redhat.com> Message-ID: <1473556188.4340686.1346157956568.JavaMail.root@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, This patch stops multiple block allocations if a nonzero return code is received from gfs2_rbm_from_block. Without this patch, if enough pressure is put on the file system, you get a kernel warning quickly followed by: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] gfs2_alloc_blocks+0x2c8/0x880 [gfs2] With this patch, things run normally. Regards, Bob Peterson Red Hat File Systems Signed-off-by: Bob Peterson --- diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 87ee0b7..081fba8 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -1852,8 +1852,7 @@ static void gfs2_alloc_extent(const struct gfs2_rbm *rbm, bool dinode, block++; while (*n < elen) { ret = gfs2_rbm_from_block(&pos, block); - WARN_ON(ret); - if (gfs2_testbit(&pos) != GFS2_BLKST_FREE) + if (ret || gfs2_testbit(&pos) != GFS2_BLKST_FREE) break; gfs2_trans_add_bh(pos.rgd->rd_gl, pos.bi->bi_bh, 1); gfs2_setbit(&pos, true, GFS2_BLKST_USED);