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 - on-memory private data of ifile
  34  * @mi: on-memory private data of metadata file
  35  * @palloc_cache: persistent object allocator cache of ifile
  36  */
  37 struct nilfs_ifile_info {
  38         struct nilfs_mdt_info mi;
  39         struct nilfs_palloc_cache palloc_cache;
  40 };
  41
  42 static inline struct nilfs_ifile_info *NILFS_IFILE_I(struct inode *ifile)
  43 {
  44         return (struct nilfs_ifile_info *)NILFS_MDT(ifile);
  45 }
  46
  47 /**
  48  * nilfs_ifile_create_inode - create a new disk inode
  49  * @ifile: ifile inode
  50  * @out_ino: pointer to a variable to store inode number
  51  * @out_bh: buffer_head contains newly allocated disk inode
  52  *
  53  * Return Value: On success, 0 is returned and the newly allocated inode
  54  * number is stored in the place pointed by @ino, and buffer_head pointer
  55  * that contains newly allocated disk inode structure is stored in the
  56  * place pointed by @out_bh
  57  * On error, one of the following negative error codes is returned.
  58  *
  59  * %-EIO - I/O error.
  60  *
  61  * %-ENOMEM - Insufficient amount of memory available.
  62  *
  63  * %-ENOSPC - No inode left.
  64  */
  65 int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,
  66                              struct buffer_head **out_bh)
  67 {
  68         struct nilfs_palloc_req req;
  69         int ret;
  70
  71         req.pr_entry_nr = 0;  /* 0 says find free inode from beginning of
  72                                  a group. dull code!! */
  73         req.pr_entry_bh = NULL;
  74
  75         ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
  76         if (!ret) {
  77                 ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
  78                                                    &req.pr_entry_bh);
  79                 if (ret < 0)
  80                         nilfs_palloc_abort_alloc_entry(ifile, &req);
  81         }
  82         if (ret < 0) {
  83                 brelse(req.pr_entry_bh);
  84                 return ret;
  85         }
  86         nilfs_palloc_commit_alloc_entry(ifile, &req);
  87         mark_buffer_dirty(req.pr_entry_bh);
  88         nilfs_mdt_mark_dirty(ifile);
  89         *out_ino = (ino_t)req.pr_entry_nr;
  90         *out_bh = req.pr_entry_bh;
  91         return 0;
  92 }
  93
  94 /**
  95  * nilfs_ifile_delete_inode - delete a disk inode
  96  * @ifile: ifile inode
  97  * @ino: inode number
  98  *
  99  * Return Value: On success, 0 is returned. On error, one of the following
 100  * negative error codes is returned.
 101  *
 102  * %-EIO - I/O error.
 103  *
 104  * %-ENOMEM - Insufficient amount of memory available.
 105  *
 106  * %-ENOENT - The inode number @ino have not been allocated.
 107  */
 108 int nilfs_ifile_delete_inode(struct inode *ifile, ino_t ino)
 109 {
 110         struct nilfs_palloc_req req = {
 111                 .pr_entry_nr = ino, .pr_entry_bh = NULL
 112         };
 113         struct nilfs_inode *raw_inode;
 114         void *kaddr;
 115         int ret;
 116
 117         ret = nilfs_palloc_prepare_free_entry(ifile, &req);
 118         if (!ret) {
 119                 ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 0,
 120                                                    &req.pr_entry_bh);
 121                 if (ret < 0)
 122                         nilfs_palloc_abort_free_entry(ifile, &req);
 123         }
 124         if (ret < 0) {
 125                 brelse(req.pr_entry_bh);
 126                 return ret;
 127         }
 128
 129         kaddr = kmap_atomic(req.pr_entry_bh->b_page);
 130         raw_inode = nilfs_palloc_block_get_entry(ifile, req.pr_entry_nr,
 131                                                  req.pr_entry_bh, kaddr);
 132         raw_inode->i_flags = 0;
 133         kunmap_atomic(kaddr);
 134
 135         mark_buffer_dirty(req.pr_entry_bh);
 136         brelse(req.pr_entry_bh);
 137
 138         nilfs_palloc_commit_free_entry(ifile, &req);
 139
 140         return 0;
 141 }
 142
 143 int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
 144                                 struct buffer_head **out_bh)
 145 {
 146         struct super_block *sb = ifile->i_sb;
 147         int err;
 148
 149         if (unlikely(!NILFS_VALID_INODE(sb, ino))) {
 150                 nilfs_error(sb, __func__, "bad inode number: %lu",
 151                             (unsigned long) ino);
 152                 return -EINVAL;
 153         }
 154
 155         err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);
 156         if (unlikely(err))
 157                 nilfs_warning(sb, __func__, "unable to read inode: %lu",
 158                               (unsigned long) ino);
 159         return err;
 160 }
 161
 162 /**
 163  * nilfs_ifile_count_free_inodes - calculate free inodes count
 164  * @ifile: ifile inode
 165  * @nmaxinodes: current maximum of available inodes count [out]
 166  * @nfreeinodes: free inodes count [out]
 167  */
 168 int nilfs_ifile_count_free_inodes(struct inode *ifile,
 169                                     u64 *nmaxinodes, u64 *nfreeinodes)
 170 {
 171         u64 nused;
 172         int err;
 173
 174         *nmaxinodes = 0;
 175         *nfreeinodes = 0;
 176
 177         nused = atomic64_read(&NILFS_I(ifile)->i_root->inodes_count);
 178         err = nilfs_palloc_count_max_entries(ifile, nused, nmaxinodes);
 179         if (likely(!err))
 180                 *nfreeinodes = *nmaxinodes - nused;
 181         return err;
 182 }
 183
 184 /**
 185  * nilfs_ifile_read - read or get ifile inode
 186  * @sb: super block instance
 187  * @root: root object
 188  * @inode_size: size of an inode
 189  * @raw_inode: on-disk ifile inode
 190  * @inodep: buffer to store the inode
 191  */
 192 int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
 193                      size_t inode_size, struct nilfs_inode *raw_inode,
 194                      struct inode **inodep)
 195 {
 196         struct inode *ifile;
 197         int err;
 198
 199         ifile = nilfs_iget_locked(sb, root, NILFS_IFILE_INO);
 200         if (unlikely(!ifile))
 201                 return -ENOMEM;
 202         if (!(ifile->i_state & I_NEW))
 203                 goto out;
 204
 205         err = nilfs_mdt_init(ifile, NILFS_MDT_GFP,
 206                              sizeof(struct nilfs_ifile_info));
 207         if (err)
 208                 goto failed;
 209
 210         err = nilfs_palloc_init_blockgroup(ifile, inode_size);
 211         if (err)
 212                 goto failed;
 213
 214         nilfs_palloc_setup_cache(ifile, &NILFS_IFILE_I(ifile)->palloc_cache);
 215
 216         err = nilfs_read_inode_common(ifile, raw_inode);
 217         if (err)
 218                 goto failed;
 219
 220         unlock_new_inode(ifile);
 221  out:
 222         *inodep = ifile;
 223         return 0;
 224  failed:
 225         iget_failed(ifile);
 226         return err;
 227 }