fs/nilfs2/ifile.c

   1 /*
   2  * ifile.c - NILFS inode 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 Amagai Yoshiji <amagai@osrg.net>.
  21  * Revised by Ryusuke Konishi <ryusuke@osrg.net>.
  22  *
  23  */
  24
  25 #include <linux/types.h>
  26 #include <linux/buffer_head.h>
  27 #include "nilfs.h"
  28 #include "mdt.h"
  29 #include "alloc.h"
  30 #include "ifile.h"
  31
  32 /**
  33  * nilfs_ifile_create_inode - create a new disk inode
  34  * @ifile: ifile inode
  35  * @out_ino: pointer to a variable to store inode number
  36  * @out_bh: buffer_head contains newly allocated disk inode
  37  *
  38  * Return Value: On success, 0 is returned and the newly allocated inode
  39  * number is stored in the place pointed by @ino, and buffer_head pointer
  40  * that contains newly allocated disk inode structure is stored in the
  41  * place pointed by @out_bh
  42  * On error, one of the following negative error codes is returned.
  43  *
  44  * %-EIO - I/O error.
  45  *
  46  * %-ENOMEM - Insufficient amount of memory available.
  47  *
  48  * %-ENOSPC - No inode left.
  49  */
  50 int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,
  51                              struct buffer_head **out_bh)
  52 {
  53         struct nilfs_palloc_req req;
  54         int ret;
  55
  56         req.pr_entry_nr = 0;  /* 0 says find free inode from beginning of
  57                                  a group. dull code!! */
  58         req.pr_entry_bh = NULL;
  59
  60         ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
  61         if (!ret) {
  62                 ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
  63                                                    &req.pr_entry_bh);
  64                 if (ret < 0)
  65                         nilfs_palloc_abort_alloc_entry(ifile, &req);
  66         }
  67         if (ret < 0) {
  68                 brelse(req.pr_entry_bh);
  69                 return ret;
  70         }
  71         nilfs_palloc_commit_alloc_entry(ifile, &req);
  72         nilfs_mdt_mark_buffer_dirty(req.pr_entry_bh);
  73         nilfs_mdt_mark_dirty(ifile);
  74         *out_ino = (ino_t)req.pr_entry_nr;
  75         *out_bh = req.pr_entry_bh;
  76         return 0;
  77 }
  78
  79 /**
  80  * nilfs_ifile_delete_inode - delete a disk inode
  81  * @ifile: ifile inode
  82  * @ino: inode number
  83  *
  84  * Return Value: On success, 0 is returned. On error, one of the following
  85  * negative error codes is returned.
  86  *
  87  * %-EIO - I/O error.
  88  *
  89  * %-ENOMEM - Insufficient amount of memory available.
  90  *
  91  * %-ENOENT - The inode number @ino have not been allocated.
  92  */
  93 int nilfs_ifile_delete_inode(struct inode *ifile, ino_t ino)
  94 {
  95         struct nilfs_palloc_req req = {
  96                 .pr_entry_nr = ino, .pr_entry_bh = NULL
  97         };
  98         struct nilfs_inode *raw_inode;
  99         void *kaddr;
 100         int ret;
 101
 102         ret = nilfs_palloc_prepare_free_entry(ifile, &req);
 103         if (!ret) {
 104                 ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 0,
 105                                                    &req.pr_entry_bh);
 106                 if (ret < 0)
 107                         nilfs_palloc_abort_free_entry(ifile, &req);
 108         }
 109         if (ret < 0) {
 110                 brelse(req.pr_entry_bh);
 111                 return ret;
 112         }
 113
 114         kaddr = kmap_atomic(req.pr_entry_bh->b_page, KM_USER0);
 115         raw_inode = nilfs_palloc_block_get_entry(ifile, req.pr_entry_nr,
 116                                                  req.pr_entry_bh, kaddr);
 117         raw_inode->i_flags = 0;
 118         kunmap_atomic(kaddr, KM_USER0);
 119
 120         nilfs_mdt_mark_buffer_dirty(req.pr_entry_bh);
 121         brelse(req.pr_entry_bh);
 122
 123         nilfs_palloc_commit_free_entry(ifile, &req);
 124
 125         return 0;
 126 }
 127
 128 int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
 129                                 struct buffer_head **out_bh)
 130 {
 131         struct super_block *sb = ifile->i_sb;
 132         int err;
 133
 134         if (unlikely(!NILFS_VALID_INODE(sb, ino))) {
 135                 nilfs_error(sb, __func__, "bad inode number: %lu",
 136                             (unsigned long) ino);
 137                 return -EINVAL;
 138         }
 139
 140         err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);
 141         if (unlikely(err)) {
 142                 if (err == -EINVAL)
 143                         nilfs_error(sb, __func__, "ifile is broken");
 144                 else
 145                         nilfs_warning(sb, __func__,
 146                                       "unable to read inode: %lu",
 147                                       (unsigned long) ino);
 148         }
 149         return err;
 150 }