nilfs2: move cleanup code of metadata file from inode routines

Refactor nilfs_clear_inode() and nilfs_i_callback() so that cleanup
code or resource deallocation related to metadata file will be moved
out to mdt.c.

Link: http://lkml.kernel.org/r/1461935747-10380-9-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nilfs2/inode.c

@@ -755,7 +755,6 @@ void nilfs_truncate(struct inode *inode)
 static void nilfs_clear_inode(struct inode *inode)
 {
 	struct nilfs_inode_info *ii = NILFS_I(inode);
-	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 
 	/*
 	 * Free resources allocated in nilfs_read_inode(), here.
@@ -764,8 +763,8 @@ static void nilfs_clear_inode(struct inode *inode)
 	brelse(ii->i_bh);
 	ii->i_bh = NULL;
 
-	if (mdi && mdi->mi_palloc_cache)
-		nilfs_palloc_destroy_cache(inode);
+	if (nilfs_is_metadata_file_inode(inode))
+		nilfs_mdt_clear(inode);
 
 	if (test_bit(NILFS_I_BMAP, &ii->i_state))
 		nilfs_bmap_clear(ii->i_bmap);

fs/nilfs2/mdt.c

@@ -28,6 +28,7 @@
 #include "segment.h"
 #include "page.h"
 #include "mdt.h"
+#include "alloc.h"		/* nilfs_palloc_destroy_cache() */
 
 #include <trace/events/nilfs2.h>
 
@@ -465,6 +466,30 @@ int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
 	return 0;
 }
 
+/**
+ * nilfs_mdt_clear - do cleanup for the metadata file
+ * @inode: inode of the metadata file
+ */
+void nilfs_mdt_clear(struct inode *inode)
+{
+	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
+
+	if (mdi->mi_palloc_cache)
+		nilfs_palloc_destroy_cache(inode);
+}
+
+/**
+ * nilfs_mdt_destroy - release resources used by the metadata file
+ * @inode: inode of the metadata file
+ */
+void nilfs_mdt_destroy(struct inode *inode)
+{
+	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
+
+	kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
+	kfree(mdi);
+}
+
 void nilfs_mdt_set_entry_size(struct inode *inode, unsigned entry_size,
 			      unsigned header_size)
 {

fs/nilfs2/mdt.h

@@ -67,6 +67,11 @@ static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
 	return inode->i_private;
 }
 
+static inline int nilfs_is_metadata_file_inode(const struct inode *inode)
+{
+	return inode->i_private != NULL;
+}
+
 /* Default GFP flags using highmem */
 #define NILFS_MDT_GFP      (__GFP_RECLAIM | __GFP_IO | __GFP_HIGHMEM)
 
@@ -82,6 +87,9 @@ int nilfs_mdt_forget_block(struct inode *, unsigned long);
 int nilfs_mdt_fetch_dirty(struct inode *);
 
 int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz);
+void nilfs_mdt_clear(struct inode *inode);
+void nilfs_mdt_destroy(struct inode *inode);
+
 void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
 
 int nilfs_mdt_setup_shadow_map(struct inode *inode,

fs/nilfs2/super.c

@@ -169,12 +169,10 @@ struct inode *nilfs_alloc_inode(struct super_block *sb)
 static void nilfs_i_callback(struct rcu_head *head)
 {
 	struct inode *inode = container_of(head, struct inode, i_rcu);
-	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 
-	if (mdi) {
-		kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
-		kfree(mdi);
-	}
+	if (nilfs_is_metadata_file_inode(inode))
+		nilfs_mdt_destroy(inode);
+
 	kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 }