From: Peng Tao <tao.peng@emc.com>
Date: Mon, 25 Jun 2012 13:31:18 +0000 (+0800)
Subject: LU-1322 llite: revalidate dentry if f_version is 0
X-Git-Tag: v1_8_9_WC1_RC1~32
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=b3f95c01348185e64d6b184d2fc7a21b1551b2ff;p=fs%2Flustre-release.git

LU-1322 llite: revalidate dentry if f_version is 0

If a file is lseek()ed before i_version changes, it is possible
for application to call into ll_readdir and have f_pos pointing
to some garbage data and cause kernel hang.

Signed-off-by: Peng Tao <tao.peng@emc.com>
Change-Id: I49ab94ad5c63c3029d5ad96e27e38e124a135ed8
Reviewed-on: http://review.whamcloud.com/3181
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Lai Siyao <laisiyao@whamcloud.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
---

diff --git a/lustre/llite/dir.c b/lustre/llite/dir.c
index 4e94c2a..588929c 100644
--- a/lustre/llite/dir.c
+++ b/lustre/llite/dir.c
@@ -348,7 +348,8 @@ static int ll_readdir_18(struct file *filp, void *dirent, filldir_t filldir)
         pgoff_t idx         = pos >> CFS_PAGE_SHIFT;
         pgoff_t npages      = dir_pages(inode);
         unsigned chunk_mask = ll_dir_page_mask(inode);
-        int need_revalidate = (filp->f_version != inode->i_version);
+        int need_revalidate = (filp->f_version == 0 ||
+                               filp->f_version != inode->i_version);
         int rc              = 0;
         int done; /* when this becomes negative --- stop iterating */