nilfs2: introduce nilfs_prepare_super
This function checks validity of super block pointers.
If first super block is invalid, it will swap the super blocks.
The function should be called before any super block information updates.
Caller must obtain nilfs->ns_sem.
Signed-off-by: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 1f7881c..9e680a9 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2408,6 +2408,7 @@
{
struct nilfs_sb_info *sbi = sci->sc_sbi;
struct the_nilfs *nilfs = sbi->s_nilfs;
+ struct nilfs_super_block **sbp;
int err = 0;
nilfs_segctor_accept(sci);
@@ -2423,8 +2424,11 @@
if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
nilfs_discontinued(nilfs)) {
down_write(&nilfs->ns_sem);
- err = nilfs_commit_super(
- sbi, nilfs_altsb_need_update(nilfs));
+ err = -EIO;
+ sbp = nilfs_prepare_super(sbi);
+ if (likely(sbp))
+ err = nilfs_commit_super(
+ sbi, nilfs_altsb_need_update(nilfs));
up_write(&nilfs->ns_sem);
}
}