f2fs: add migrate_page to avoid patch conflicts

This is disabled by default.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/checkpoint.c

@@ -387,6 +387,9 @@ const struct address_space_operations f2fs_meta_aops = {
 	.set_page_dirty	= f2fs_set_meta_page_dirty,
 	.invalidatepage = f2fs_invalidate_page,
 	.releasepage	= f2fs_release_page,
+#ifdef CONFIG_F2FS_MIGRATION
+	.migratepage    = f2fs_migrate_page,
+#endif
 };
 
 static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type)

fs/f2fs/data.c

@@ -1971,6 +1971,58 @@ static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
 	return generic_block_bmap(mapping, block, get_data_block_bmap);
 }
 
+#ifdef CONFIG_F2FS_MIGRATION
+#include <linux/migrate.h>
+
+int f2fs_migrate_page(struct address_space *mapping,
+		struct page *newpage, struct page *page, enum migrate_mode mode)
+{
+	int rc, extra_count;
+	struct f2fs_inode_info *fi = F2FS_I(mapping->host);
+	bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
+
+	BUG_ON(PageWriteback(page));
+
+	/* migrating an atomic written page is safe with the inmem_lock hold */
+	if (atomic_written && !mutex_trylock(&fi->inmem_lock))
+		return -EAGAIN;
+
+	/*
+	 * A reference is expected if PagePrivate set when move mapping,
+	 * however F2FS breaks this for maintaining dirty page counts when
+	 * truncating pages. So here adjusting the 'extra_count' make it work.
+	 */
+	extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
+	rc = migrate_page_move_mapping(mapping, newpage,
+				page, NULL, mode, extra_count);
+	if (rc != MIGRATEPAGE_SUCCESS) {
+		if (atomic_written)
+			mutex_unlock(&fi->inmem_lock);
+		return rc;
+	}
+
+	if (atomic_written) {
+		struct inmem_pages *cur;
+		list_for_each_entry(cur, &fi->inmem_pages, list)
+			if (cur->page == page) {
+				cur->page = newpage;
+				break;
+			}
+		mutex_unlock(&fi->inmem_lock);
+		put_page(page);
+		get_page(newpage);
+	}
+
+	if (PagePrivate(page))
+		SetPagePrivate(newpage);
+	set_page_private(newpage, page_private(page));
+
+	migrate_page_copy(newpage, page);
+
+	return MIGRATEPAGE_SUCCESS;
+}
+#endif
+
 const struct address_space_operations f2fs_dblock_aops = {
 	.readpage	= f2fs_read_data_page,
 	.readpages	= f2fs_read_data_pages,
@@ -1983,4 +2035,7 @@ const struct address_space_operations f2fs_dblock_aops = {
 	.releasepage	= f2fs_release_page,
 	.direct_IO	= f2fs_direct_IO,
 	.bmap		= f2fs_bmap,
+#ifdef CONFIG_F2FS_MIGRATION
+	.migratepage    = f2fs_migrate_page,
+#endif
 };

fs/f2fs/f2fs.h

@@ -2299,6 +2299,10 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *, u64, u64);
 void f2fs_set_page_dirty_nobuffers(struct page *);
 void f2fs_invalidate_page(struct page *, unsigned long);
 int f2fs_release_page(struct page *, gfp_t);
+#ifdef CONFIG_F2FS_MIGRATION
+int f2fs_migrate_page(struct address_space *, struct page *, struct page *,
+				enum migrate_mode);
+#endif
 
 /*
  * gc.c

fs/f2fs/key.c

@@ -0,0 +1,34 @@
+/* fill fi->keyring_key */
+int f2fs_validate_key(struct inode *inode)
+{
+	u8 full_key_descriptor[FS_KEY_DESC_PREFIX_SIZE +
+				(FS_KEY_DESCRIPTOR_SIZE * 2) + 1];
+	struct key *keyring_key = NULL;
+	u8 key[F2FS_SET_KEY_SIZE];
+	int ret;
+
+	ret = f2fs_getxattr(inode, F2FS_XATTR_INDEX_KEY,
+				F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
+				key, F2FS_SET_KEY_SIZE, NULL);
+	if (ret)
+		return ret;
+
+	memcpy(full_key_descriptor, F2FS_KEY_DESC_PREFIX,
+					F2FS_KEY_DESC_PREFIX_SIZE);
+	sprintf(full_key_descriptor + F2FS_KEY_DESC_PREFIX_SIZE,
+					"%*phN", F2FS_KEY_DESCRIPTOR_SIZE, key);
+	full_key_descriptor[F2FS_KEY_DESC_PREFIX_SIZE +
+					(2 * F2FS_KEY_DESCRIPTOR_SIZE)] = '\0';
+	keyring_key = request_key(&key_type_logon, full_key_descriptor, NULL);
+	if (IS_ERR(keyring_key))
+		return PTR_ERR(keyring_key);
+
+	if (keyring_key->type != &key_type_logon) {
+		printk_once(KERN_WARNING
+				"%s: key type must be logon\n", __func__);
+		key_put(keyring_key);
+		return -ENOKEY;
+	}
+	key_put(keyring_key);
+	return 0;
+}

fs/f2fs/node.c

@@ -1705,6 +1705,9 @@ const struct address_space_operations f2fs_node_aops = {
 	.set_page_dirty	= f2fs_set_node_page_dirty,
 	.invalidatepage	= f2fs_invalidate_page,
 	.releasepage	= f2fs_release_page,
+#ifdef CONFIG_F2FS_MIGRATION
+	.migratepage    = f2fs_migrate_page,
+#endif
 };
 
 static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,