[JFFS2][XATTR] XATTR support on JFFS2 (version. 5)

This attached patches provide xattr support including POSIX-ACL and
SELinux support on JFFS2 (version.5).

There are some significant differences from previous version posted
at last December.
The biggest change is addition of EBS(Erase Block Summary) support.
Currently, both kernel and usermode utility (sumtool) can recognize
xattr nodes which have JFFS2_NODETYPE_XATTR/_XREF nodetype.

In addition, some bugs are fixed.
- A potential race condition was fixed.
- Unexpected fail when updating a xattr by same name/value pair was fixed.
- A bug when removing xattr name/value pair was fixed.

The fundamental structures (such as using two new nodetypes and exclusion
mechanism by rwsem) are unchanged. But most of implementation were reviewed
and updated if necessary.
Espacially, we had to change several internal implementations related to
load_xattr_datum() to avoid a potential race condition.

[1/2] xattr_on_jffs2.kernel.version-5.patch
[2/2] xattr_on_jffs2.utils.version-5.patch

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h
index 4bcfb557022..3b4e0edd6db 100644
--- a/fs/jffs2/jffs2_fs_sb.h
+++ b/fs/jffs2/jffs2_fs_sb.h
@@ -115,6 +115,16 @@ struct jffs2_sb_info {
 
 	struct jffs2_summary *summary;		/* Summary information */
 
+#ifdef CONFIG_JFFS2_FS_XATTR
+#define XATTRINDEX_HASHSIZE	(57)
+	uint32_t highest_xid;
+	struct list_head xattrindex[XATTRINDEX_HASHSIZE];
+	struct list_head xattr_temp;
+	struct list_head xattr_unchecked;
+	struct rw_semaphore xattr_sem;
+	uint32_t xdatum_mem_usage;
+	uint32_t xdatum_mem_threshold;
+#endif
 	/* OS-private pointer for getting back to master superblock info */
 	void *os_priv;
 };