xattr.h

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2006  NEC Corporation
 *
 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#ifndef _JFFS2_FS_XATTR_H_
#define _JFFS2_FS_XATTR_H_

#include <linux/xattr.h>
#include <linux/list.h>

#define JFFS2_XFLAGS_HOT    (0x01)  /* This datum is HOT */
#define JFFS2_XFLAGS_BIND   (0x02)  /* This datum is not reclaimed */
#define JFFS2_XFLAGS_DEAD   (0x40)  /* This datum is already dead */
#define JFFS2_XFLAGS_INVALID    (0x80)  /* This datum contains crc error */

struct jffs2_xattr_datum
{
    void *always_null;
    struct jffs2_raw_node_ref *node;
    uint8_t class;
    uint8_t flags;
    uint16_t xprefix;       /* see JFFS2_XATTR_PREFIX_* */

    struct list_head xindex;    /* chained from c->xattrindex[n] */
    atomic_t refcnt;        /* # of xattr_ref refers this */
    uint32_t xid;
    uint32_t version;

    uint32_t data_crc;
    uint32_t hashkey;
    char *xname;        /* XATTR name without prefix */
    uint32_t name_len;  /* length of xname */
    char *xvalue;       /* XATTR value */
    uint32_t value_len; /* length of xvalue */
};

struct jffs2_inode_cache;
struct jffs2_xattr_ref
{
    void *always_null;
    struct jffs2_raw_node_ref *node;
    uint8_t class;
    uint8_t flags;      /* Currently unused */
    u16 unused;

    uint32_t xseqno;
    union {
        struct jffs2_inode_cache *ic;   /* reference to jffs2_inode_cache */
        uint32_t ino;           /* only used in scanning/building  */
    };
    union {
        struct jffs2_xattr_datum *xd;   /* reference to jffs2_xattr_datum */
        uint32_t xid;           /* only used in sccanning/building */
    };
    struct jffs2_xattr_ref *next;       /* chained from ic->xref_list */
};

#define XREF_DELETE_MARKER  (0x00000001)
static inline int is_xattr_ref_dead(struct jffs2_xattr_ref *ref)
{
    return ((ref->xseqno & XREF_DELETE_MARKER) != 0);
}

#ifdef CONFIG_JFFS2_FS_XATTR

extern void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c);
extern void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c);
extern void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c);

extern struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
                             uint32_t xid, uint32_t version);

extern void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
extern void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
extern void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);

extern int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
                         struct jffs2_raw_node_ref *raw);
extern int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
                       struct jffs2_raw_node_ref *raw);
extern int jffs2_verify_xattr(struct jffs2_sb_info *c);
extern void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd);
extern void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref);

extern int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
                 char *buffer, size_t size);
extern int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
                 const char *buffer, size_t size, int flags);

extern const struct xattr_handler *jffs2_xattr_handlers[];
extern const struct xattr_handler jffs2_user_xattr_handler;
extern const struct xattr_handler jffs2_trusted_xattr_handler;

extern ssize_t jffs2_listxattr(struct dentry *, char *, size_t);

#else

#define jffs2_init_xattr_subsystem(c)
#define jffs2_build_xattr_subsystem(c)
#define jffs2_clear_xattr_subsystem(c)

#define jffs2_xattr_do_crccheck_inode(c, ic)
#define jffs2_xattr_delete_inode(c, ic)
#define jffs2_xattr_free_inode(c, ic)
#define jffs2_verify_xattr(c)           (1)

#define jffs2_xattr_handlers    NULL
#define jffs2_listxattr     NULL

#endif /* CONFIG_JFFS2_FS_XATTR */

#ifdef CONFIG_JFFS2_FS_SECURITY
extern int jffs2_init_security(struct inode *inode, struct inode *dir,
                   const struct qstr *qstr);
extern const struct xattr_handler jffs2_security_xattr_handler;
#else
#define jffs2_init_security(inode,dir,qstr) (0)
#endif /* CONFIG_JFFS2_FS_SECURITY */

#endif /* _JFFS2_FS_XATTR_H_ */