f2fs: introduce NODE_MAPPING for code consistency

This patch adds NODE_MAPPING which is similar as META_MAPPING introduced by
Gu Zheng.

Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

4 files changed, 30 insertions, 31 deletions

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index ed82de6bfb47..293d0486a40f 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -771,7 +771,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
         /* wait for previous submitted node/meta pages writeback */
         wait_on_all_pages_writeback(sbi);
 
-        filemap_fdatawait_range(sbi->node_inode->i_mapping, 0, LONG_MAX);
+        filemap_fdatawait_range(NODE_MAPPING(sbi), 0, LONG_MAX);
         filemap_fdatawait_range(META_MAPPING(sbi), 0, LONG_MAX);
 
         /* update user_block_counts */
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 8bdc365be9e3..3de9d20d0c14 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -52,7 +52,7 @@ static void update_general_status(struct f2fs_sb_info *sbi)
         si->free_secs = free_sections(sbi);
         si->prefree_count = prefree_segments(sbi);
         si->dirty_count = dirty_segments(sbi);
-        si->node_pages = sbi->node_inode->i_mapping->nrpages;
+        si->node_pages = NODE_MAPPING(sbi)->nrpages;
         si->meta_pages = META_MAPPING(sbi)->nrpages;
         si->nats = NM_I(sbi)->nat_cnt;
         si->sits = SIT_I(sbi)->dirty_sentries;
@@ -166,7 +166,7 @@ get_cache:
         /* free nids */
         si->cache_mem = NM_I(sbi)->fcnt;
         si->cache_mem += NM_I(sbi)->nat_cnt;
-        npages = sbi->node_inode->i_mapping->nrpages;
+        npages = NODE_MAPPING(sbi)->nrpages;
         si->cache_mem += npages << PAGE_CACHE_SHIFT;
         npages = META_MAPPING(sbi)->nrpages;
         si->cache_mem += npages << PAGE_CACHE_SHIFT;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 117e30f6b88c..af51a0bd2dee 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -538,6 +538,11 @@ static inline struct address_space *META_MAPPING(struct f2fs_sb_info *sbi)
         return sbi->meta_inode->i_mapping;
 }
 
+static inline struct address_space *NODE_MAPPING(struct f2fs_sb_info *sbi)
+{
+        return sbi->node_inode->i_mapping;
+}
+
 static inline void F2FS_SET_SB_DIRT(struct f2fs_sb_info *sbi)
 {
         sbi->s_dirty = 1;
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 527bd12d8ae1..bbfc655493dc 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -681,7 +681,6 @@ fail:
 int truncate_inode_blocks(struct inode *inode, pgoff_t from)
 {
         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
-        struct address_space *node_mapping = sbi->node_inode->i_mapping;
         int err = 0, cont = 1;
         int level, offset[4], noffset[4];
         unsigned int nofs = 0;
@@ -756,7 +755,7 @@ skip_partial:
                 if (offset[1] == 0 &&
                                 ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
                         lock_page(page);
-                        if (unlikely(page->mapping != node_mapping)) {
+                        if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
                                 f2fs_put_page(page, 1);
                                 goto restart;
                         }
@@ -842,7 +841,6 @@ struct page *new_node_page(struct dnode_of_data *dn,
                                 unsigned int ofs, struct page *ipage)
 {
         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
-        struct address_space *mapping = sbi->node_inode->i_mapping;
         struct node_info old_ni, new_ni;
         struct page *page;
         int err;
@@ -850,7 +848,7 @@ struct page *new_node_page(struct dnode_of_data *dn,
         if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
                 return ERR_PTR(-EPERM);
 
-        page = grab_cache_page(mapping, dn->nid);
+        page = grab_cache_page(NODE_MAPPING(sbi), dn->nid);
         if (!page)
                 return ERR_PTR(-ENOMEM);
 
@@ -920,18 +918,17 @@ static int read_node_page(struct page *page, int rw)
  */
 void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
 {
-        struct address_space *mapping = sbi->node_inode->i_mapping;
         struct page *apage;
         int err;
 
-        apage = find_get_page(mapping, nid);
+        apage = find_get_page(NODE_MAPPING(sbi), nid);
         if (apage && PageUptodate(apage)) {
                 f2fs_put_page(apage, 0);
                 return;
         }
         f2fs_put_page(apage, 0);
 
-        apage = grab_cache_page(mapping, nid);
+        apage = grab_cache_page(NODE_MAPPING(sbi), nid);
         if (!apage)
                 return;
 
@@ -944,11 +941,10 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
 
 struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
 {
-        struct address_space *mapping = sbi->node_inode->i_mapping;
         struct page *page;
         int err;
 repeat:
-        page = grab_cache_page(mapping, nid);
+        page = grab_cache_page(NODE_MAPPING(sbi), nid);
         if (!page)
                 return ERR_PTR(-ENOMEM);
 
@@ -963,7 +959,7 @@ repeat:
                 f2fs_put_page(page, 1);
                 return ERR_PTR(-EIO);
         }
-        if (unlikely(page->mapping != mapping)) {
+        if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
                 f2fs_put_page(page, 1);
                 goto repeat;
         }
@@ -980,7 +976,6 @@ got_it:
 struct page *get_node_page_ra(struct page *parent, int start)
 {
         struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb);
-        struct address_space *mapping = sbi->node_inode->i_mapping;
         struct blk_plug plug;
         struct page *page;
         int err, i, end;
@@ -991,7 +986,7 @@ struct page *get_node_page_ra(struct page *parent, int start)
         if (!nid)
                 return ERR_PTR(-ENOENT);
 repeat:
-        page = grab_cache_page(mapping, nid);
+        page = grab_cache_page(NODE_MAPPING(sbi), nid);
         if (!page)
                 return ERR_PTR(-ENOMEM);
 
@@ -1016,7 +1011,7 @@ repeat:
         blk_finish_plug(&plug);
 
         lock_page(page);
-        if (unlikely(page->mapping != mapping)) {
+        if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
                 f2fs_put_page(page, 1);
                 goto repeat;
         }
@@ -1047,7 +1042,6 @@ void sync_inode_page(struct dnode_of_data *dn)
 int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
                                         struct writeback_control *wbc)
 {
-        struct address_space *mapping = sbi->node_inode->i_mapping;
         pgoff_t index, end;
         struct pagevec pvec;
         int step = ino ? 2 : 0;
@@ -1061,7 +1055,7 @@ next_step:
 
         while (index <= end) {
                 int i, nr_pages;
-                nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+                nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
                                 PAGECACHE_TAG_DIRTY,
                                 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
                 if (nr_pages == 0)
@@ -1094,7 +1088,7 @@ next_step:
                         else if (!trylock_page(page))
                                 continue;
 
-                        if (unlikely(page->mapping != mapping)) {
+                        if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
 continue_unlock:
                                 unlock_page(page);
                                 continue;
@@ -1121,7 +1115,7 @@ continue_unlock:
                                 set_fsync_mark(page, 0);
                                 set_dentry_mark(page, 0);
                         }
-                        mapping->a_ops->writepage(page, wbc);
+                        NODE_MAPPING(sbi)->a_ops->writepage(page, wbc);
                         wrote++;
 
                         if (--wbc->nr_to_write == 0)
@@ -1148,18 +1142,19 @@ continue_unlock:
 
 int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
 {
-        struct address_space *mapping = sbi->node_inode->i_mapping;
         pgoff_t index = 0, end = LONG_MAX;
         struct pagevec pvec;
-        int nr_pages;
         int ret2 = 0, ret = 0;
 
         pagevec_init(&pvec, 0);
-        while ((index <= end) &&
-                        (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
-                        PAGECACHE_TAG_WRITEBACK,
-                        min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1)) != 0) {
-                unsigned i;
+
+        while (index <= end) {
+                int i, nr_pages;
+                nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+                                PAGECACHE_TAG_WRITEBACK,
+                                min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+                if (nr_pages == 0)
+                        break;
 
                 for (i = 0; i < nr_pages; i++) {
                         struct page *page = pvec.pages[i];
@@ -1178,9 +1173,9 @@ int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
                 cond_resched();
         }
 
-        if (unlikely(test_and_clear_bit(AS_ENOSPC, &mapping->flags)))
+        if (unlikely(test_and_clear_bit(AS_ENOSPC, &NODE_MAPPING(sbi)->flags)))
                 ret2 = -ENOSPC;
-        if (unlikely(test_and_clear_bit(AS_EIO, &mapping->flags)))
+        if (unlikely(test_and_clear_bit(AS_EIO, &NODE_MAPPING(sbi)->flags)))
                 ret2 = -EIO;
         if (!ret)
                 ret = ret2;
@@ -1538,13 +1533,12 @@ void recover_node_page(struct f2fs_sb_info *sbi, struct page *page,
 
 int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
 {
-        struct address_space *mapping = sbi->node_inode->i_mapping;
         struct f2fs_inode *src, *dst;
         nid_t ino = ino_of_node(page);
         struct node_info old_ni, new_ni;
         struct page *ipage;
 
-        ipage = grab_cache_page(mapping, ino);
+        ipage = grab_cache_page(NODE_MAPPING(sbi), ino);
         if (!ipage)
                 return -ENOMEM;