From: Swapnil Pimpale <spimpale@ddn.com>
Date: Wed, 31 Jul 2013 12:07:25 +0000 (+0530)
Subject: LU-2940 llite: Fix for oops in vvp_pgcache_show()
X-Git-Tag: 2.4.90~5
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=f5e8090ae871c6075c29bb378da1204ef9c7beeb;p=fs%2Flustre-release.git

LU-2940 llite: Fix for oops in vvp_pgcache_show()

Hold the lock protecting page tree (coh_page_guard) till the point the page is
being accessed.

Signed-off-by: Swapnil Pimpale <spimpale@ddn.com>
Change-Id: I9d1d5129d9cac8f1fa5eec77f554320c0c255fc2
Reviewed-on: http://review.whamcloud.com/7192
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lustre/llite/vvp_dev.c b/lustre/llite/vvp_dev.c
index c0a636d..68ea741 100644
--- a/lustre/llite/vvp_dev.c
+++ b/lustre/llite/vvp_dev.c
@@ -453,7 +453,6 @@ static int vvp_pgcache_show(struct seq_file *f, void *v)
 
 			spin_lock(&hdr->coh_page_guard);
 			page = cl_page_lookup(hdr, id.vpi_index);
-			spin_unlock(&hdr->coh_page_guard);
 
                         seq_printf(f, "%8x@"DFID": ",
                                    id.vpi_index, PFID(&hdr->coh_lu.loh_fid));
@@ -462,6 +461,7 @@ static int vvp_pgcache_show(struct seq_file *f, void *v)
                                 cl_page_put(env, page);
                         } else
                                 seq_puts(f, "missing\n");
+			spin_unlock(&hdr->coh_page_guard);
                         lu_object_ref_del(&clob->co_lu, "dump", cfs_current());
                         cl_object_put(env, clob);
                 } else