From 1154ecbd2f8298ef75609f5f8ed5aca96be599fb Mon Sep 17 00:00:00 2001 From: Zhang Qiang Date: Tue, 18 Aug 2009 14:58:24 +0800 Subject: [PATCH] nilfs2: missing a read lock for segment writer in nilfs_attach_checkpoint() 'ns_cno' of structure 'the_nilfs' must be protected from segment writer, in other words, the caller of nilfs_get_checkpoint should hold read lock for nilfs->ns_segctor_sem. This patch adds the lock/unlock operations in nilfs_attach_checkpoint() when calling nilfs_cpfile_get_checkpoint(). Signed-off-by: Zhang Qiang Signed-off-by: Ryusuke Konishi --- fs/nilfs2/super.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 8e2ec43..151964f 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -416,8 +416,10 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) if (unlikely(err)) goto failed; + down_read(&nilfs->ns_segctor_sem); err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, &bh_cp); + up_read(&nilfs->ns_segctor_sem); if (unlikely(err)) { if (err == -ENOENT || err == -EINVAL) { printk(KERN_ERR -- 2.7.4