1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2006  NEC Corporation
5  *
6  * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  */
11 
12 #ifndef _JFFS2_FS_XATTR_H_
13 #define _JFFS2_FS_XATTR_H_
14 
15 #include <linux/xattr.h>
16 #include <linux/list.h>
17 
18 #define JFFS2_XFLAGS_HOT	(0x01)	/* This datum is HOT */
19 #define JFFS2_XFLAGS_BIND	(0x02)	/* This datum is not reclaimed */
20 #define JFFS2_XFLAGS_DEAD	(0x40)	/* This datum is already dead */
21 #define JFFS2_XFLAGS_INVALID	(0x80)	/* This datum contains crc error */
22 
23 struct jffs2_xattr_datum
24 {
25 	void *always_null;
26 	struct jffs2_raw_node_ref *node;
27 	uint8_t class;
28 	uint8_t flags;
29 	uint16_t xprefix;		/* see JFFS2_XATTR_PREFIX_* */
30 
31 	struct list_head xindex;	/* chained from c->xattrindex[n] */
32 	atomic_t refcnt;		/* # of xattr_ref refers this */
33 	uint32_t xid;
34 	uint32_t version;
35 
36 	uint32_t data_crc;
37 	uint32_t hashkey;
38 	char *xname;		/* XATTR name without prefix */
39 	uint32_t name_len;	/* length of xname */
40 	char *xvalue;		/* XATTR value */
41 	uint32_t value_len;	/* length of xvalue */
42 };
43 
44 struct jffs2_inode_cache;
45 struct jffs2_xattr_ref
46 {
47 	void *always_null;
48 	struct jffs2_raw_node_ref *node;
49 	uint8_t class;
50 	uint8_t flags;		/* Currently unused */
51 	u16 unused;
52 
53 	uint32_t xseqno;
54 	union {
55 		struct jffs2_inode_cache *ic;	/* reference to jffs2_inode_cache */
56 		uint32_t ino;			/* only used in scanning/building  */
57 	};
58 	union {
59 		struct jffs2_xattr_datum *xd;	/* reference to jffs2_xattr_datum */
60 		uint32_t xid;			/* only used in sccanning/building */
61 	};
62 	struct jffs2_xattr_ref *next;		/* chained from ic->xref_list */
63 };
64 
65 #define XREF_DELETE_MARKER	(0x00000001)
is_xattr_ref_dead(struct jffs2_xattr_ref * ref)66 static inline int is_xattr_ref_dead(struct jffs2_xattr_ref *ref)
67 {
68 	return ((ref->xseqno & XREF_DELETE_MARKER) != 0);
69 }
70 
71 #ifdef CONFIG_JFFS2_FS_XATTR
72 
73 extern void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c);
74 extern void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c);
75 extern void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c);
76 
77 extern struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
78 							 uint32_t xid, uint32_t version);
79 
80 extern void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
81 extern void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
82 extern void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
83 
84 extern int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
85 					     struct jffs2_raw_node_ref *raw);
86 extern int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
87 					   struct jffs2_raw_node_ref *raw);
88 extern int jffs2_verify_xattr(struct jffs2_sb_info *c);
89 extern void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd);
90 extern void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref);
91 
92 extern int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
93 			     char *buffer, size_t size);
94 extern int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
95 			     const char *buffer, size_t size, int flags);
96 
97 extern const struct xattr_handler *jffs2_xattr_handlers[];
98 extern const struct xattr_handler jffs2_user_xattr_handler;
99 extern const struct xattr_handler jffs2_trusted_xattr_handler;
100 
101 extern ssize_t jffs2_listxattr(struct dentry *, char *, size_t);
102 
103 #else
104 
105 #define jffs2_init_xattr_subsystem(c)
106 #define jffs2_build_xattr_subsystem(c)
107 #define jffs2_clear_xattr_subsystem(c)
108 
109 #define jffs2_xattr_do_crccheck_inode(c, ic)
110 #define jffs2_xattr_delete_inode(c, ic)
111 #define jffs2_xattr_free_inode(c, ic)
112 #define jffs2_verify_xattr(c)			(1)
113 
114 #define jffs2_xattr_handlers	NULL
115 #define jffs2_listxattr		NULL
116 
117 #endif /* CONFIG_JFFS2_FS_XATTR */
118 
119 #ifdef CONFIG_JFFS2_FS_SECURITY
120 extern int jffs2_init_security(struct inode *inode, struct inode *dir,
121 			       const struct qstr *qstr);
122 extern const struct xattr_handler jffs2_security_xattr_handler;
123 #else
124 #define jffs2_init_security(inode,dir,qstr)	(0)
125 #endif /* CONFIG_JFFS2_FS_SECURITY */
126 
127 #endif /* _JFFS2_FS_XATTR_H_ */
128