nilfs2: always set back pointer to host inode in mapping->host

In the current nilfs, page cache for btree nodes and meta data files
do not set a valid back pointer to the host inode in mapping->host.

This will change it so that every address space in nilfs uses
mapping->host to hold its host inode.

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

8 files changed, 14 insertions, 36 deletions

diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c
index 481756042423..c353e4fa600c 100644
--- a/fs/nilfs2/btnode.c
+++ b/fs/nilfs2/btnode.c
@@ -34,12 +34,6 @@
 #include "page.h"
 #include "btnode.h"
 
-void nilfs_btnode_cache_init(struct address_space *btnc,
-                             struct backing_dev_info *bdi)
-{
-        nilfs_mapping_init(btnc, bdi);
-}
-
 void nilfs_btnode_cache_clear(struct address_space *btnc)
 {
         invalidate_mapping_pages(btnc, 0, -1);
diff --git a/fs/nilfs2/btnode.h b/fs/nilfs2/btnode.h
index 1b8ebd888c28..7de449c2e2a3 100644
--- a/fs/nilfs2/btnode.h
+++ b/fs/nilfs2/btnode.h
@@ -37,7 +37,6 @@ struct nilfs_btnode_chkey_ctxt {
         struct buffer_head *newbh;
 };
 
-void nilfs_btnode_cache_init(struct address_space *, struct backing_dev_info *);
 void nilfs_btnode_cache_clear(struct address_space *);
 struct buffer_head *nilfs_btnode_create_block(struct address_space *btnc,
                                               __u64 blocknr);
diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
index a649b05f7069..6790ca689c17 100644
--- a/fs/nilfs2/mdt.c
+++ b/fs/nilfs2/mdt.c
@@ -450,9 +450,9 @@ int nilfs_mdt_setup_shadow_map(struct inode *inode,
 
         INIT_LIST_HEAD(&shadow->frozen_buffers);
         address_space_init_once(&shadow->frozen_data);
-        nilfs_mapping_init(&shadow->frozen_data, bdi);
+        nilfs_mapping_init(&shadow->frozen_data, inode, bdi);
         address_space_init_once(&shadow->frozen_btnodes);
-        nilfs_mapping_init(&shadow->frozen_btnodes, bdi);
+        nilfs_mapping_init(&shadow->frozen_btnodes, inode, bdi);
         mi->mi_shadow = shadow;
         return 0;
 }
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 09af00999ec0..a9c6a531f80c 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -80,12 +80,6 @@ static inline struct inode *NILFS_BTNC_I(struct address_space *btnc)
         return &ii->vfs_inode;
 }
 
-static inline struct inode *NILFS_AS_I(struct address_space *mapping)
-{
-        return (mapping->host) ? :
-                container_of(mapping, struct inode, i_data);
-}
-
 /*
  * Dynamic state flags of NILFS on-memory inode (i_state)
  */
diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index b3b988c2018f..3f18f5c076e8 100644
--- a/fs/nilfs2/page.c
+++ b/fs/nilfs2/page.c
@@ -182,7 +182,7 @@ int nilfs_page_buffers_clean(struct page *page)
 void nilfs_page_bug(struct page *page)
 {
         struct address_space *m;
-        unsigned long ino = 0;
+        unsigned long ino;
 
         if (unlikely(!page)) {
                 printk(KERN_CRIT "NILFS_PAGE_BUG(NULL)\n");
@@ -190,11 +190,8 @@ void nilfs_page_bug(struct page *page)
         }
 
         m = page->mapping;
-        if (m) {
-                struct inode *inode = NILFS_AS_I(m);
-                if (inode != NULL)
-                        ino = inode->i_ino;
-        }
+        ino = m ? m->host->i_ino : 0;
+
         printk(KERN_CRIT "NILFS_PAGE_BUG(%p): cnt=%d index#=%llu flags=0x%lx "
                "mapping=%p ino=%lu\n",
                page, atomic_read(&page->_count),
@@ -441,10 +438,10 @@ unsigned nilfs_page_count_clean_buffers(struct page *page,
         return nc;
 }
 
-void nilfs_mapping_init(struct address_space *mapping,
+void nilfs_mapping_init(struct address_space *mapping, struct inode *inode,
                         struct backing_dev_info *bdi)
 {
-        mapping->host = NULL;
+        mapping->host = inode;
         mapping->flags = 0;
         mapping_set_gfp_mask(mapping, GFP_NOFS);
         mapping->assoc_mapping = NULL;
diff --git a/fs/nilfs2/page.h b/fs/nilfs2/page.h
index f827afabd548..e301e5661c36 100644
--- a/fs/nilfs2/page.h
+++ b/fs/nilfs2/page.h
@@ -57,7 +57,7 @@ void nilfs_page_bug(struct page *);
 int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
 void nilfs_copy_back_pages(struct address_space *, struct address_space *);
 void nilfs_clear_dirty_pages(struct address_space *);
-void nilfs_mapping_init(struct address_space *mapping,
+void nilfs_mapping_init(struct address_space *mapping, struct inode *inode,
                         struct backing_dev_info *bdi);
 unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
 unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 186cabbe54d7..eeb1bc2c76ca 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -655,13 +655,10 @@ static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
                 if (unlikely(page->index > last))
                         break;
 
-                if (mapping->host) {
-                        lock_page(page);
-                        if (!page_has_buffers(page))
-                                create_empty_buffers(page,
-                                                     1 << inode->i_blkbits, 0);
-                        unlock_page(page);
-                }
+                lock_page(page);
+                if (!page_has_buffers(page))
+                        create_empty_buffers(page, 1 << inode->i_blkbits, 0);
+                unlock_page(page);
 
                 bh = head = page_buffers(page);
                 do {
@@ -1503,10 +1500,7 @@ nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
                         nblocks = le32_to_cpu(finfo->fi_nblocks);
                         ndatablk = le32_to_cpu(finfo->fi_ndatablk);
 
-                        if (buffer_nilfs_node(bh))
-                                inode = NILFS_BTNC_I(bh->b_page->mapping);
-                        else
-                                inode = NILFS_AS_I(bh->b_page->mapping);
+                        inode = bh->b_page->mapping->host;
 
                         if (mode == SC_LSEG_DSYNC)
                                 sc_op = &nilfs_sc_dsync_ops;
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 2846491071ce..8351c44a7320 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -166,7 +166,7 @@ struct inode *nilfs_alloc_inode(struct super_block *sb)
         ii->i_state = 0;
         ii->i_cno = 0;
         ii->vfs_inode.i_version = 1;
-        nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi);
+        nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode, sb->s_bdi);
         return &ii->vfs_inode;
 }