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
  16 struct inode;
  17 struct gfs2_inode;
  18 struct gfs2_inum;
  19 struct buffer_head;
  20 struct gfs2_dirent;
  21
  22 struct gfs2_diradd {
  23         unsigned nr_blocks;
  24         struct gfs2_dirent *dent;
  25         struct buffer_head *bh;
  26         int save_loc;
  27 };
  28
  29 extern struct inode *gfs2_dir_search(struct inode *dir,
  30                                      const struct qstr *filename,
  31                                      bool fail_on_exist);
  32 extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,
  33                           const struct gfs2_inode *ip);
  34 extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,
  35                         const struct gfs2_inode *ip, struct gfs2_diradd *da);
  36 static inline void gfs2_dir_no_add(struct gfs2_diradd *da)
  37 {
  38         if (da->bh)
  39                 brelse(da->bh);
  40         da->bh = NULL;
  41 }
  42 extern int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry);
  43 extern int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
  44                          struct file_ra_state *f_ra);
  45 extern int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
  46                           const struct gfs2_inode *nip, unsigned int new_type);
  47
  48 extern int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip);
  49
  50 extern int gfs2_diradd_alloc_required(struct inode *dir,
  51                                       const struct qstr *filename,
  52                                       struct gfs2_diradd *da);
  53 extern int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
  54                                    struct buffer_head **bhp);
  55 extern void gfs2_dir_hash_inval(struct gfs2_inode *ip);
  56
  57 static inline u32 gfs2_disk_hash(const char *data, int len)
  58 {
  59         return crc32_le((u32)~0, data, len) ^ (u32)~0;
  60 }
  61
  62
  63 static 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 */
  71 static 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
  83 extern struct qstr gfs2_qdot;
  84 extern struct qstr gfs2_qdotdot;
  85
  86 #endif /* __DIR_DOT_H__ */