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 };
  27
  28 extern struct inode *gfs2_dir_search(struct inode *dir,
  29                                      const struct qstr *filename,
  30                                      bool fail_on_exist);
  31 extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,
  32                           const struct gfs2_inode *ip);
  33 extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,
  34                         const struct gfs2_inode *ip, struct gfs2_diradd *da);
  35 static inline void gfs2_dir_no_add(struct gfs2_diradd *da)
  36 {
  37         if (da->bh)
  38                 brelse(da->bh);
  39         da->bh = NULL;
  40 }
  41 extern int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry);
  42 extern int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
  43                          struct file_ra_state *f_ra);
  44 extern int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
  45                           const struct gfs2_inode *nip, unsigned int new_type);
  46
  47 extern int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip);
  48
  49 extern int gfs2_diradd_alloc_required(struct inode *dir,
  50                                       const struct qstr *filename,
  51                                       struct gfs2_diradd *da);
  52 extern int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
  53                                    struct buffer_head **bhp);
  54 extern void gfs2_dir_hash_inval(struct gfs2_inode *ip);
  55
  56 static inline u32 gfs2_disk_hash(const char *data, int len)
  57 {
  58         return crc32_le((u32)~0, data, len) ^ (u32)~0;
  59 }
  60
  61
  62 static inline void gfs2_str2qstr(struct qstr *name, const char *fname)
  63 {
  64         name->name = fname;
  65         name->len = strlen(fname);
  66         name->hash = gfs2_disk_hash(name->name, name->len);
  67 }
  68
  69 /* N.B. This probably ought to take inum & type as args as well */
  70 static inline void gfs2_qstr2dirent(const struct qstr *name, u16 reclen, struct gfs2_dirent *dent)
  71 {
  72         dent->de_inum.no_addr = cpu_to_be64(0);
  73         dent->de_inum.no_formal_ino = cpu_to_be64(0);
  74         dent->de_hash = cpu_to_be32(name->hash);
  75         dent->de_rec_len = cpu_to_be16(reclen);
  76         dent->de_name_len = cpu_to_be16(name->len);
  77         dent->de_type = cpu_to_be16(0);
  78         memset(dent->__pad, 0, sizeof(dent->__pad));
  79         memcpy(dent + 1, name->name, name->len);
  80 }
  81
  82 extern struct qstr gfs2_qdot;
  83 extern struct qstr gfs2_qdotdot;
  84
  85 #endif /* __DIR_DOT_H__ */