f2fs: support the inline xattrs

0. modified inode structure
--------------------------------------
metadata (e.g., i_mtime, i_ctime, etc)
--------------------------------------
direct pointers [0 ~ 873]

inline xattrs (200 bytes by default)

indirect pointers [0 ~ 4]
--------------------------------------
node footer
--------------------------------------

1. setxattr flow
 - read_all_xattrs copies all the xattrs from inline and xattr node block.
 - handle xattr entries
 - write_all_xattrs copies modified xattrs into inline and xattr node block.

2. getxattr flow
 - read_all_xattrs copies all the xattrs from inline and xattr node block.
 - check target entries

3. Usage
 # mount -t f2fs -o inline_xattr $DEV $MNT

 Once mounted with the inline_xattr option, f2fs marks all the newly created
 files to reserve an amount of inline xattr space explicitly inside the inode
 block. Without the mount option, f2fs will not touch any existing files and
 newly created files as well.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/fs/f2fs/xattr.h b/fs/f2fs/xattr.h
index c3ec042707d..02a08fb88a1 100644
--- a/fs/f2fs/xattr.h
+++ b/fs/f2fs/xattr.h
@@ -69,16 +69,16 @@ struct f2fs_xattr_entry {
 				!IS_XATTR_LAST_ENTRY(entry);\
 				entry = XATTR_NEXT_ENTRY(entry))
 
-#define MIN_OFFSET	XATTR_ALIGN(PAGE_SIZE - \
-			sizeof(struct node_footer) - \
-			sizeof(__u32))
+#define MIN_OFFSET(i)	XATTR_ALIGN(inline_xattr_size(i) + PAGE_SIZE -	\
+				sizeof(struct node_footer) - sizeof(__u32))
 
-#define MAX_VALUE_LEN	(MIN_OFFSET - sizeof(struct f2fs_xattr_header) - \
-			sizeof(struct f2fs_xattr_entry))
+#define MAX_VALUE_LEN(i)	(MIN_OFFSET(i) -			\
+				sizeof(struct f2fs_xattr_header) -	\
+				sizeof(struct f2fs_xattr_entry))
 
 /*
  * On-disk structure of f2fs_xattr
- * We use only 1 block for xattr.
+ * We use inline xattrs space + 1 block for xattr.
  *
  * +--------------------+
  * | f2fs_xattr_header  |