LXR linux/fs/gfs2/dir.h

   1/*
   2 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4 *
   5 * This copyrighted material is made available to anyone wishing to use,
   6 * modify, copy, or redistribute it subject to the terms and conditions
   7 * of the GNU General Public License version 2.
   8 */
   9
  10#ifndef __DIR_DOT_H__
  11#define __DIR_DOT_H__
  12
  13#include <linux/dcache.h>
  14#include <linux/crc32.h>
  15
  16struct inode;
  17struct gfs2_inode;
  18struct gfs2_inum;
  19struct buffer_head;
  20struct gfs2_dirent;
  21
  22struct gfs2_diradd {
  23        unsigned nr_blocks;
  24        struct gfs2_dirent *dent;
  25        struct buffer_head *bh;
  26        int save_loc;
  27};
  28
  29extern struct inode *gfs2_dir_search(struct inode *dir,
  30                                     const struct qstr *filename,
  31                                     bool fail_on_exist);
  32extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,
  33                          const struct gfs2_inode *ip);
  34extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,
  35                        const struct gfs2_inode *ip, struct gfs2_diradd *da);
  36static inline void gfs2_dir_no_add(struct gfs2_diradd *da)
  37{
  38        if (da->bh)
  39                brelse(da->bh);
  40        da->bh = NULL;
  41}
  42extern int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry);
  43extern int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
  44                         struct file_ra_state *f_ra);
  45extern int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
  46                          const struct gfs2_inode *nip, unsigned int new_type);
  47
  48extern int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip);
  49
  50extern int gfs2_diradd_alloc_required(struct inode *dir,
  51                                      const struct qstr *filename,
  52                                      struct gfs2_diradd *da);
  53extern int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
  54                                   struct buffer_head **bhp);
  55extern void gfs2_dir_hash_inval(struct gfs2_inode *ip);
  56
  57static inline u32 gfs2_disk_hash(const char *data, int len)
  58{
  59        return crc32_le((u32)~0, data, len) ^ (u32)~0;
  60}
  61
  62
  63static inline void gfs2_str2qstr(struct qstr *name, const char *fname)
  64{
  65        name->name = fname;
  66        name->len = strlen(fname);
  67        name->hash = gfs2_disk_hash(name->name, name->len);
  68}
  69
  70/* N.B. This probably ought to take inum & type as args as well */
  71static inline void gfs2_qstr2dirent(const struct qstr *name, u16 reclen, struct gfs2_dirent *dent)
  72{
  73        dent->de_inum.no_addr = cpu_to_be64(0);
  74        dent->de_inum.no_formal_ino = cpu_to_be64(0);
  75        dent->de_hash = cpu_to_be32(name->hash);
  76        dent->de_rec_len = cpu_to_be16(reclen);
  77        dent->de_name_len = cpu_to_be16(name->len);
  78        dent->de_type = cpu_to_be16(0);
  79        memset(dent->__pad, 0, sizeof(dent->__pad));
  80        memcpy(dent + 1, name->name, name->len);
  81}
  82
  83extern struct qstr gfs2_qdot;
  84extern struct qstr gfs2_qdotdot;
  85
  86#endif /* __DIR_DOT_H__ */
  87