fs/nilfs2/sufile.h

   1 /*
   2  * sufile.h - NILFS segment usage file.
   3  *
   4  * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Koji Sato <koji@osrg.net>.
  21  */
  22
  23 #ifndef _NILFS_SUFILE_H
  24 #define _NILFS_SUFILE_H
  25
  26 #include <linux/fs.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/nilfs2_fs.h>
  29 #include "mdt.h"
  30
  31 #define NILFS_SUFILE_GFP        NILFS_MDT_GFP
  32
  33 static inline unsigned long nilfs_sufile_get_nsegments(struct inode *sufile)
  34 {
  35         return NILFS_MDT(sufile)->mi_nilfs->ns_nsegments;
  36 }
  37
  38 int nilfs_sufile_alloc(struct inode *, __u64 *);
  39 int nilfs_sufile_get_segment_usage(struct inode *, __u64,
  40                                    struct nilfs_segment_usage **,
  41                                    struct buffer_head **);
  42 void nilfs_sufile_put_segment_usage(struct inode *, __u64,
  43                                     struct buffer_head *);
  44 int nilfs_sufile_get_stat(struct inode *, struct nilfs_sustat *);
  45 int nilfs_sufile_get_ncleansegs(struct inode *, unsigned long *);
  46 ssize_t nilfs_sufile_get_suinfo(struct inode *, __u64, struct nilfs_suinfo *,
  47                                 size_t);
  48
  49 int nilfs_sufile_update(struct inode *, __u64, int,
  50                         void (*dofunc)(struct inode *, __u64,
  51                                        struct buffer_head *,
  52                                        struct buffer_head *));
  53 void nilfs_sufile_do_cancel_free(struct inode *, __u64, struct buffer_head *,
  54                                  struct buffer_head *);
  55 void nilfs_sufile_do_scrap(struct inode *, __u64, struct buffer_head *,
  56                            struct buffer_head *);
  57 void nilfs_sufile_do_free(struct inode *, __u64, struct buffer_head *,
  58                           struct buffer_head *);
  59 void nilfs_sufile_do_set_error(struct inode *, __u64, struct buffer_head *,
  60                                struct buffer_head *);
  61
  62 /**
  63  * nilfs_sufile_cancel_free -
  64  * @sufile: inode of segment usage file
  65  * @segnum: segment number
  66  *
  67  * Description:
  68  *
  69  * Return Value: On success, 0 is returned. On error, one of the following
  70  * negative error codes is returned.
  71  *
  72  * %-EIO - I/O error.
  73  *
  74  * %-ENOMEM - Insufficient amount of memory available.
  75  */
  76 static inline int nilfs_sufile_cancel_free(struct inode *sufile, __u64 segnum)
  77 {
  78         return nilfs_sufile_update(sufile, segnum, 0,
  79                                    nilfs_sufile_do_cancel_free);
  80 }
  81
  82 /**
  83  * nilfs_sufile_scrap - make a segment garbage
  84  * @sufile: inode of segment usage file
  85  * @segnum: segment number to be freed
  86  */
  87 static inline int nilfs_sufile_scrap(struct inode *sufile, __u64 segnum)
  88 {
  89         return nilfs_sufile_update(sufile, segnum, 1, nilfs_sufile_do_scrap);
  90 }
  91
  92 /**
  93  * nilfs_sufile_free - free segment
  94  * @sufile: inode of segment usage file
  95  * @segnum: segment number to be freed
  96  */
  97 static inline int nilfs_sufile_free(struct inode *sufile, __u64 segnum)
  98 {
  99         return nilfs_sufile_update(sufile, segnum, 0, nilfs_sufile_do_free);
 100 }
 101
 102 /**
 103  * nilfs_sufile_set_error - mark a segment as erroneous
 104  * @sufile: inode of segment usage file
 105  * @segnum: segment number
 106  *
 107  * Description: nilfs_sufile_set_error() marks the segment specified by
 108  * @segnum as erroneous. The error segment will never be used again.
 109  *
 110  * Return Value: On success, 0 is returned. On error, one of the following
 111  * negative error codes is returned.
 112  *
 113  * %-EIO - I/O error.
 114  *
 115  * %-ENOMEM - Insufficient amount of memory available.
 116  *
 117  * %-EINVAL - Invalid segment usage number.
 118  */
 119 static inline int nilfs_sufile_set_error(struct inode *sufile, __u64 segnum)
 120 {
 121         return nilfs_sufile_update(sufile, segnum, 0,
 122                                    nilfs_sufile_do_set_error);
 123 }
 124
 125 #endif  /* _NILFS_SUFILE_H */