nilfs2: add more check routines in mount process
nilfs2: Add more safeguard routines and protections in mount process,
which also makes nilfs2 report consistency error messages when
checkpoint number is invalid.
Signed-off-by: Zhu Yanhai <zhu.yanhai@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index aec942c..1c6cfb5 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -815,8 +815,10 @@
void *kaddr;
int ret;
- if (cno == 0)
- return -ENOENT; /* checkpoint number 0 is invalid */
+ /* CP number is invalid if it's zero or larger than the
+ largest exist one.*/
+ if (cno == 0 || cno >= nilfs_mdt_cno(cpfile))
+ return -ENOENT;
down_read(&NILFS_MDT(cpfile)->mi_sem);
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
@@ -824,7 +826,10 @@
goto out;
kaddr = kmap_atomic(bh->b_page, KM_USER0);
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
- ret = nilfs_checkpoint_snapshot(cp);
+ if (nilfs_checkpoint_invalid(cp))
+ ret = -ENOENT;
+ else
+ ret = nilfs_checkpoint_snapshot(cp);
kunmap_atomic(kaddr, KM_USER0);
brelse(bh);