nilfs2: add nilfs_cleanup_super

This function write out filesystem state to super blocks in order to
share the same cleanup work.  This is a preparation for making super
block writeback alternately.

Cc: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

3 files changed, 23 insertions, 11 deletions

diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 47d6d7928122..469541711a1f 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -271,6 +271,7 @@ nilfs_read_super_block(struct super_block *, u64, int, struct buffer_head **);
 extern int nilfs_store_magic_and_option(struct super_block *,
                                         struct nilfs_super_block *, char *);
 extern int nilfs_commit_super(struct nilfs_sb_info *, int);
+extern int nilfs_cleanup_super(struct nilfs_sb_info *);
 extern int nilfs_attach_checkpoint(struct nilfs_sb_info *, __u64);
 extern void nilfs_detach_checkpoint(struct nilfs_sb_info *);
 
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 39b28cf3cf8e..f23a31b04e14 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -278,6 +278,24 @@ int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
         return nilfs_sync_super(sbi, dupsb);
 }
 
+/**
+ * nilfs_cleanup_super() - write filesystem state for cleanup
+ * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
+ *
+ * This function restores state flags in the on-disk super block.
+ * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
+ * filesystem was not clean previously.
+ */
+int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
+{
+        struct nilfs_super_block **sbp = sbi->s_nilfs->ns_sbp;
+        int ret;
+
+        sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
+        ret = nilfs_commit_super(sbi, 1);
+        return ret;
+}
+
 static void nilfs_put_super(struct super_block *sb)
 {
         struct nilfs_sb_info *sbi = NILFS_SB(sb);
@@ -289,8 +307,7 @@ static void nilfs_put_super(struct super_block *sb)
 
         if (!(sb->s_flags & MS_RDONLY)) {
                 down_write(&nilfs->ns_sem);
-                nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
-                nilfs_commit_super(sbi, 1);
+                nilfs_cleanup_super(sbi);
                 up_write(&nilfs->ns_sem);
         }
         down_write(&nilfs->ns_super_sem);
@@ -819,7 +836,6 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent,
 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 {
         struct nilfs_sb_info *sbi = NILFS_SB(sb);
-        struct nilfs_super_block *sbp;
         struct the_nilfs *nilfs = sbi->s_nilfs;
         unsigned long old_sb_flags;
         struct nilfs_mount_options old_opts;
@@ -880,11 +896,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
                  * the RDONLY flag and then mark the partition as valid again.
                  */
                 down_write(&nilfs->ns_sem);
-                sbp = nilfs->ns_sbp[0];
-                if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) &&
-                    (nilfs->ns_mount_state & NILFS_VALID_FS))
-                        sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
-                nilfs_commit_super(sbi, 1);
+                nilfs_cleanup_super(sbi);
                 up_write(&nilfs->ns_sem);
         } else {
                 /*
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 4a9e8a059638..ed58053b6f68 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -324,9 +324,8 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
                 goto failed_unload;
 
         down_write(&nilfs->ns_sem);
-        nilfs->ns_mount_state |= NILFS_VALID_FS;
-        nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
-        err = nilfs_commit_super(sbi, 1);
+        nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
+        err = nilfs_cleanup_super(sbi);
         up_write(&nilfs->ns_sem);
 
         if (err) {