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, 7 insertions, 0 deletions

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 2a464a76602d..c3c03c975bd6 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -787,6 +787,10 @@ int truncate_xattr_node(struct inode *inode, struct page *page)
 		return PTR_ERR(npage);
 
 	F2FS_I(inode)->i_xattr_nid = 0;
+
+	/* need to do checkpoint during fsync */
+	F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
+
 	set_new_dnode(&dn, inode, page, npage, nid);
 
 	if (page)
@@ -1464,6 +1468,9 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct free_nid *i;
 
+	if (!nid)
+		return;
+
 	spin_lock(&nm_i->free_nid_list_lock);
 	i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
 	BUG_ON(!i || i->state != NID_ALLOC);