fs/nilfs2/seglist.h

   1 /*
   2  * seglist.h - expediential structure and routines to handle list of segments
   3  *             (would be removed in a future release)
   4  *
   5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20  *
  21  * Written by Ryusuke Konishi <ryusuke@osrg.net>
  22  *
  23  */
  24 #ifndef _NILFS_SEGLIST_H
  25 #define _NILFS_SEGLIST_H
  26
  27 #include <linux/fs.h>
  28 #include <linux/buffer_head.h>
  29 #include <linux/nilfs2_fs.h>
  30 #include "sufile.h"
  31
  32 struct nilfs_segment_entry {
  33         __u64                   segnum;
  34
  35 #define NILFS_SLH_FREED         0x0001  /* The segment was freed provisonally.
  36                                            It must be cancelled if
  37                                            construction aborted */
  38
  39         unsigned                flags;
  40         struct list_head        list;
  41         struct buffer_head     *bh_su;
  42         struct nilfs_segment_usage *raw_su;
  43 };
  44
  45
  46 void nilfs_dispose_segment_list(struct list_head *);
  47
  48 static inline struct nilfs_segment_entry *
  49 nilfs_alloc_segment_entry(__u64 segnum)
  50 {
  51         struct nilfs_segment_entry *ent = kmalloc(sizeof(*ent), GFP_NOFS);
  52
  53         if (likely(ent)) {
  54                 ent->segnum = segnum;
  55                 ent->flags = 0;
  56                 ent->bh_su = NULL;
  57                 ent->raw_su = NULL;
  58                 INIT_LIST_HEAD(&ent->list);
  59         }
  60         return ent;
  61 }
  62
  63 static inline int nilfs_open_segment_entry(struct nilfs_segment_entry *ent,
  64                                            struct inode *sufile)
  65 {
  66         return nilfs_sufile_get_segment_usage(sufile, ent->segnum,
  67                                               &ent->raw_su, &ent->bh_su);
  68 }
  69
  70 static inline void nilfs_close_segment_entry(struct nilfs_segment_entry *ent,
  71                                              struct inode *sufile)
  72 {
  73         if (!ent->bh_su)
  74                 return;
  75         nilfs_sufile_put_segment_usage(sufile, ent->segnum, ent->bh_su);
  76         ent->bh_su = NULL;
  77         ent->raw_su = NULL;
  78 }
  79
  80 static inline void nilfs_free_segment_entry(struct nilfs_segment_entry *ent)
  81 {
  82         kfree(ent);
  83 }
  84
  85 #endif /* _NILFS_SEGLIST_H */