[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, 42 insertions, 0 deletions

diff --git a/fs/jffs2/summary.h b/fs/jffs2/summary.h
index b7a678be1709..a3b66c18aae9 100644
--- a/fs/jffs2/summary.h
+++ b/fs/jffs2/summary.h
@@ -45,6 +45,8 @@
 #define JFFS2_SUMMARY_NOSUM_SIZE 0xffffffff
 #define JFFS2_SUMMARY_INODE_SIZE (sizeof(struct jffs2_sum_inode_flash))
 #define JFFS2_SUMMARY_DIRENT_SIZE(x) (sizeof(struct jffs2_sum_dirent_flash) + (x))
+#define JFFS2_SUMMARY_XATTR_SIZE (sizeof(struct jffs2_sum_xattr_flash))
+#define JFFS2_SUMMARY_XREF_SIZE (sizeof(struct jffs2_sum_xref_flash))
 
 /* Summary structures used on flash */
 
@@ -75,11 +77,28 @@ struct jffs2_sum_dirent_flash
 	uint8_t name[0];	/* dirent name */
 } __attribute__((packed));
 
+struct jffs2_sum_xattr_flash
+{
+	jint16_t nodetype;	/* == JFFS2_NODETYPE_XATR */
+	jint32_t xid;		/* xattr identifier */
+	jint32_t version;	/* version number */
+	jint32_t offset;	/* offset on jeb */
+	jint32_t totlen;	/* node length */
+} __attribute__((packed));
+
+struct jffs2_sum_xref_flash
+{
+	jint16_t nodetype;	/* == JFFS2_NODETYPE_XREF */
+	jint32_t offset;	/* offset on jeb */
+} __attribute__((packed));
+
 union jffs2_sum_flash
 {
 	struct jffs2_sum_unknown_flash u;
 	struct jffs2_sum_inode_flash i;
 	struct jffs2_sum_dirent_flash d;
+	struct jffs2_sum_xattr_flash x;
+	struct jffs2_sum_xref_flash r;
 };
 
 /* Summary structures used in the memory */
@@ -114,11 +133,30 @@ struct jffs2_sum_dirent_mem
 	uint8_t name[0];	/* dirent name */
 } __attribute__((packed));
 
+struct jffs2_sum_xattr_mem
+{
+	union jffs2_sum_mem *next;
+	jint16_t nodetype;
+	jint32_t xid;
+	jint32_t version;
+	jint32_t offset;
+	jint32_t totlen;
+} __attribute__((packed));
+
+struct jffs2_sum_xref_mem
+{
+	union jffs2_sum_mem *next;
+	jint16_t nodetype;
+	jint32_t offset;
+} __attribute__((packed));
+
 union jffs2_sum_mem
 {
 	struct jffs2_sum_unknown_mem u;
 	struct jffs2_sum_inode_mem i;
 	struct jffs2_sum_dirent_mem d;
+	struct jffs2_sum_xattr_mem x;
+	struct jffs2_sum_xref_mem r;
 };
 
 /* Summary related information stored in superblock */
@@ -159,6 +197,8 @@ int jffs2_sum_write_sumnode(struct jffs2_sb_info *c);
 int jffs2_sum_add_padding_mem(struct jffs2_summary *s, uint32_t size);
 int jffs2_sum_add_inode_mem(struct jffs2_summary *s, struct jffs2_raw_inode *ri, uint32_t ofs);
 int jffs2_sum_add_dirent_mem(struct jffs2_summary *s, struct jffs2_raw_dirent *rd, uint32_t ofs);
+int jffs2_sum_add_xattr_mem(struct jffs2_summary *s, struct jffs2_raw_xattr *rx, uint32_t ofs);
+int jffs2_sum_add_xref_mem(struct jffs2_summary *s, struct jffs2_raw_xref *rr, uint32_t ofs);
 int jffs2_sum_scan_sumnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 			uint32_t ofs, uint32_t *pseudo_random);
 
@@ -176,6 +216,8 @@ int jffs2_sum_scan_sumnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb
 #define jffs2_sum_add_padding_mem(a,b)
 #define jffs2_sum_add_inode_mem(a,b,c)
 #define jffs2_sum_add_dirent_mem(a,b,c)
+#define jffs2_sum_add_xattr_mem(a,b,c)
+#define jffs2_sum_add_xref_mem(a,b,c)
 #define jffs2_sum_scan_sumnode(a,b,c,d) (0)
 
 #endif /* CONFIG_JFFS2_SUMMARY */