nilfs2: use root object to get ifile

This rewrites functions using ifile so that they get ifile from
nilfs_root object, and will remove sbi->s_ifile.  Some functions that
don't know the root object are extended to receive it from caller.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 13 insertions, 29 deletions

diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index adbf5826b837..87c57810ae88 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -358,9 +358,9 @@ static void nilfs_put_super(struct super_block *sb)
         down_write(&nilfs->ns_super_sem);
         if (nilfs->ns_current == sbi)
                 nilfs->ns_current = NULL;
+        list_del_init(&sbi->s_list);
         up_write(&nilfs->ns_super_sem);
 
-        nilfs_detach_checkpoint(sbi);
         put_nilfs(sbi->s_nilfs);
         sbi->s_super = NULL;
         sb->s_fs_info = NULL;
@@ -405,13 +405,12 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
         if (!root)
                 return err;
 
-        down_write(&nilfs->ns_super_sem);
-        list_add(&sbi->s_list, &nilfs->ns_supers);
-        up_write(&nilfs->ns_super_sem);
+        if (root->ifile)
+                goto reuse; /* already attached checkpoint */
 
-        sbi->s_ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
-        if (!sbi->s_ifile)
-                goto delist;
+        root->ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
+        if (!root->ifile)
+                goto failed;
 
         down_read(&nilfs->ns_segctor_sem);
         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
@@ -427,7 +426,7 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
                 }
                 goto failed;
         }
-        err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
+        err = nilfs_read_inode_common(root->ifile, &raw_cp->cp_ifile_inode);
         if (unlikely(err))
                 goto failed_bh;
         atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
@@ -435,35 +434,18 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
 
         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 
+ reuse:
         *rootp = root;
         return 0;
 
  failed_bh:
         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
  failed:
-        nilfs_mdt_destroy(sbi->s_ifile);
-        sbi->s_ifile = NULL;
-
- delist:
-        down_write(&nilfs->ns_super_sem);
-        list_del_init(&sbi->s_list);
-        up_write(&nilfs->ns_super_sem);
         nilfs_put_root(root);
 
         return err;
 }
 
-void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
-{
-        struct the_nilfs *nilfs = sbi->s_nilfs;
-
-        nilfs_mdt_destroy(sbi->s_ifile);
-        sbi->s_ifile = NULL;
-        down_write(&nilfs->ns_super_sem);
-        list_del_init(&sbi->s_list);
-        up_write(&nilfs->ns_super_sem);
-}
-
 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
         struct super_block *sb = dentry->d_sb;
@@ -862,7 +844,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent,
         }
 
         if (!(sb->s_flags & MS_RDONLY)) {
-                err = nilfs_attach_segment_constructor(sbi);
+                err = nilfs_attach_segment_constructor(sbi, fsroot);
                 if (err)
                         goto failed_checkpoint;
         }
@@ -896,6 +878,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent,
         }
 
         down_write(&nilfs->ns_super_sem);
+        list_add(&sbi->s_list, &nilfs->ns_supers);
         if (!nilfs_test_opt(sbi, SNAPSHOT))
                 nilfs->ns_current = sbi;
         up_write(&nilfs->ns_super_sem);
@@ -906,7 +889,6 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent,
         nilfs_detach_segment_constructor(sbi);
 
  failed_checkpoint:
-        nilfs_detach_checkpoint(sbi);
         nilfs_put_root(fsroot);
 
  failed_sbi:
@@ -966,6 +948,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
                 up_write(&nilfs->ns_sem);
         } else {
                 __u64 features;
+                struct nilfs_root *root;
 
                 /*
                  * Mounting a RDONLY partition read-write, so reread and
@@ -987,7 +970,8 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 
                 sb->s_flags &= ~MS_RDONLY;
 
-                err = nilfs_attach_segment_constructor(sbi);
+                root = NILFS_I(sb->s_root->d_inode)->i_root;
+                err = nilfs_attach_segment_constructor(sbi, root);
                 if (err)
                         goto restore_opts;