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 struct nilfs_ifile_info {
  34         struct nilfs_mdt_info mi;
  35         struct nilfs_palloc_cache palloc_cache;
  36 };
  37
  38 static inline struct nilfs_ifile_info *NILFS_IFILE_I(struct inode *ifile)
  39 {
  40         return (struct nilfs_ifile_info *)NILFS_MDT(ifile);
  41 }
  42
  43 /**
  44  * nilfs_ifile_create_inode - create a new disk inode
  45  * @ifile: ifile inode
  46  * @out_ino: pointer to a variable to store inode number
  47  * @out_bh: buffer_head contains newly allocated disk inode
  48  *
  49  * Return Value: On success, 0 is returned and the newly allocated inode
  50  * number is stored in the place pointed by @ino, and buffer_head pointer
  51  * that contains newly allocated disk inode structure is stored in the
  52  * place pointed by @out_bh
  53  * On error, one of the following negative error codes is returned.
  54  *
  55  * %-EIO - I/O error.
  56  *
  57  * %-ENOMEM - Insufficient amount of memory available.
  58  *
  59  * %-ENOSPC - No inode left.
  60  */
  61 int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,
  62                              struct buffer_head **out_bh)
  63 {
  64         struct nilfs_palloc_req req;
  65         int ret;
  66
  67         req.pr_entry_nr = 0;  /* 0 says find free inode from beginning of
  68                                  a group. dull code!! */
  69         req.pr_entry_bh = NULL;
  70
  71         ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
  72         if (!ret) {
  73                 ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
  74                                                    &req.pr_entry_bh);
  75                 if (ret < 0)
  76                         nilfs_palloc_abort_alloc_entry(ifile, &req);
  77         }
  78         if (ret < 0) {
  79                 brelse(req.pr_entry_bh);
  80                 return ret;
  81         }
  82         nilfs_palloc_commit_alloc_entry(ifile, &req);
  83         mark_buffer_dirty(req.pr_entry_bh);
  84         nilfs_mdt_mark_dirty(ifile);
  85         *out_ino = (ino_t)req.pr_entry_nr;
  86         *out_bh = req.pr_entry_bh;
  87         return 0;
  88 }
  89
  90 /**
  91  * nilfs_ifile_delete_inode - delete a disk inode
  92  * @ifile: ifile inode
  93  * @ino: inode number
  94  *
  95  * Return Value: On success, 0 is returned. On error, one of the following
  96  * negative error codes is returned.
  97  *
  98  * %-EIO - I/O error.
  99  *
 100  * %-ENOMEM - Insufficient amount of memory available.
 101  *
 102  * %-ENOENT - The inode number @ino have not been allocated.
 103  */
 104 int nilfs_ifile_delete_inode(struct inode *ifile, ino_t ino)
 105 {
 106         struct nilfs_palloc_req req = {
 107                 .pr_entry_nr = ino, .pr_entry_bh = NULL
 108         };
 109         struct nilfs_inode *raw_inode;
 110         void *kaddr;
 111         int ret;
 112
 113         ret = nilfs_palloc_prepare_free_entry(ifile, &req);
 114         if (!ret) {
 115                 ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 0,
 116                                                    &req.pr_entry_bh);
 117                 if (ret < 0)
 118                         nilfs_palloc_abort_free_entry(ifile, &req);
 119         }
 120         if (ret < 0) {
 121                 brelse(req.pr_entry_bh);
 122                 return ret;
 123         }
 124
 125         kaddr = kmap_atomic(req.pr_entry_bh->b_page);
 126         raw_inode = nilfs_palloc_block_get_entry(ifile, req.pr_entry_nr,
 127                                                  req.pr_entry_bh, kaddr);
 128         raw_inode->i_flags = 0;
 129         kunmap_atomic(kaddr);
 130
 131         mark_buffer_dirty(req.pr_entry_bh);
 132         brelse(req.pr_entry_bh);
 133
 134         nilfs_palloc_commit_free_entry(ifile, &req);
 135
 136         return 0;
 137 }
 138
 139 int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
 140                                 struct buffer_head **out_bh)
 141 {
 142         struct super_block *sb = ifile->i_sb;
 143         int err;
 144
 145         if (unlikely(!NILFS_VALID_INODE(sb, ino))) {
 146                 nilfs_error(sb, __func__, "bad inode number: %lu",
 147                             (unsigned long) ino);
 148                 return -EINVAL;
 149         }
 150
 151         err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);
 152         if (unlikely(err))
 153                 nilfs_warning(sb, __func__, "unable to read inode: %lu",
 154                               (unsigned long) ino);
 155         return err;
 156 }
 157
 158 /**
 159  * nilfs_ifile_read - read or get ifile inode
 160  * @sb: super block instance
 161  * @root: root object
 162  * @inode_size: size of an inode
 163  * @raw_inode: on-disk ifile inode
 164  * @inodep: buffer to store the inode
 165  */
 166 int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
 167                      size_t inode_size, struct nilfs_inode *raw_inode,
 168                      struct inode **inodep)
 169 {
 170         struct inode *ifile;
 171         int err;
 172
 173         ifile = nilfs_iget_locked(sb, root, NILFS_IFILE_INO);
 174         if (unlikely(!ifile))
 175                 return -ENOMEM;
 176         if (!(ifile->i_state & I_NEW))
 177                 goto out;
 178
 179         err = nilfs_mdt_init(ifile, NILFS_MDT_GFP,
 180                              sizeof(struct nilfs_ifile_info));
 181         if (err)
 182                 goto failed;
 183
 184         err = nilfs_palloc_init_blockgroup(ifile, inode_size);
 185         if (err)
 186                 goto failed;
 187
 188         nilfs_palloc_setup_cache(ifile, &NILFS_IFILE_I(ifile)->palloc_cache);
 189
 190         err = nilfs_read_inode_common(ifile, raw_inode);
 191         if (err)
 192                 goto failed;
 193
 194         unlock_new_inode(ifile);
 195  out:
 196         *inodep = ifile;
 197         return 0;
 198  failed:
 199         iget_failed(ifile);
 200         return err;
 201 }