Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: fix oopses with doubly mounted snapshots
  nilfs2: missing a read lock for segment writer in nilfs_attach_checkpoint()

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 8e2ec43b18f4..151964f0de4c 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