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  * Written by Amagai Yoshiji.
  17  * Revised by Ryusuke Konishi.
  18  *
  19  */
  20
  21 #include <linux/types.h>
  22 #include <linux/buffer_head.h>
  23 #include "nilfs.h"
  24 #include "mdt.h"
  25 #include "alloc.h"
  26 #include "ifile.h"
  27
  28 /**
  29  * struct nilfs_ifile_info - on-memory private data of ifile
  30  * @mi: on-memory private data of metadata file
  31  * @palloc_cache: persistent object allocator cache of ifile
  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;  /*
  68                                * 0 says find free inode from beginning
  69                                * of a group. dull code!!
  70                                */
  71         req.pr_entry_bh = NULL;
  72
  73         ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
  74         if (!ret) {
  75                 ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
  76                                                    &req.pr_entry_bh);
  77                 if (ret < 0)
  78                         nilfs_palloc_abort_alloc_entry(ifile, &req);
  79         }
  80         if (ret < 0) {
  81                 brelse(req.pr_entry_bh);
  82                 return ret;
  83         }
  84         nilfs_palloc_commit_alloc_entry(ifile, &req);
  85         mark_buffer_dirty(req.pr_entry_bh);
  86         nilfs_mdt_mark_dirty(ifile);
  87         *out_ino = (ino_t)req.pr_entry_nr;
  88         *out_bh = req.pr_entry_bh;
  89         return 0;
  90 }
  91
  92 /**
  93  * nilfs_ifile_delete_inode - delete a disk inode
  94  * @ifile: ifile inode
  95  * @ino: inode number
  96  *
  97  * Return Value: On success, 0 is returned. On error, one of the following
  98  * negative error codes is returned.
  99  *
 100  * %-EIO - I/O error.
 101  *
 102  * %-ENOMEM - Insufficient amount of memory available.
 103  *
 104  * %-ENOENT - The inode number @ino have not been allocated.
 105  */
 106 int nilfs_ifile_delete_inode(struct inode *ifile, ino_t ino)
 107 {
 108         struct nilfs_palloc_req req = {
 109                 .pr_entry_nr = ino, .pr_entry_bh = NULL
 110         };
 111         struct nilfs_inode *raw_inode;
 112         void *kaddr;
 113         int ret;
 114
 115         ret = nilfs_palloc_prepare_free_entry(ifile, &req);
 116         if (!ret) {
 117                 ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 0,
 118                                                    &req.pr_entry_bh);
 119                 if (ret < 0)
 120                         nilfs_palloc_abort_free_entry(ifile, &req);
 121         }
 122         if (ret < 0) {
 123                 brelse(req.pr_entry_bh);
 124                 return ret;
 125         }
 126
 127         kaddr = kmap_atomic(req.pr_entry_bh->b_page);
 128         raw_inode = nilfs_palloc_block_get_entry(ifile, req.pr_entry_nr,
 129                                                  req.pr_entry_bh, kaddr);
 130         raw_inode->i_flags = 0;
 131         kunmap_atomic(kaddr);
 132
 133         mark_buffer_dirty(req.pr_entry_bh);
 134         brelse(req.pr_entry_bh);
 135
 136         nilfs_palloc_commit_free_entry(ifile, &req);
 137
 138         return 0;
 139 }
 140
 141 int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
 142                                 struct buffer_head **out_bh)
 143 {
 144         struct super_block *sb = ifile->i_sb;
 145         int err;
 146
 147         if (unlikely(!NILFS_VALID_INODE(sb, ino))) {
 148                 nilfs_error(sb, __func__, "bad inode number: %lu",
 149                             (unsigned long) ino);
 150                 return -EINVAL;
 151         }
 152
 153         err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);
 154         if (unlikely(err))
 155                 nilfs_warning(sb, __func__, "unable to read inode: %lu",
 156                               (unsigned long) ino);
 157         return err;
 158 }
 159
 160 /**
 161  * nilfs_ifile_count_free_inodes - calculate free inodes count
 162  * @ifile: ifile inode
 163  * @nmaxinodes: current maximum of available inodes count [out]
 164  * @nfreeinodes: free inodes count [out]
 165  */
 166 int nilfs_ifile_count_free_inodes(struct inode *ifile,
 167                                     u64 *nmaxinodes, u64 *nfreeinodes)
 168 {
 169         u64 nused;
 170         int err;
 171
 172         *nmaxinodes = 0;
 173         *nfreeinodes = 0;
 174
 175         nused = atomic64_read(&NILFS_I(ifile)->i_root->inodes_count);
 176         err = nilfs_palloc_count_max_entries(ifile, nused, nmaxinodes);
 177         if (likely(!err))
 178                 *nfreeinodes = *nmaxinodes - nused;
 179         return err;
 180 }
 181
 182 /**
 183  * nilfs_ifile_read - read or get ifile inode
 184  * @sb: super block instance
 185  * @root: root object
 186  * @inode_size: size of an inode
 187  * @raw_inode: on-disk ifile inode
 188  * @inodep: buffer to store the inode
 189  */
 190 int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
 191                      size_t inode_size, struct nilfs_inode *raw_inode,
 192                      struct inode **inodep)
 193 {
 194         struct inode *ifile;
 195         int err;
 196
 197         ifile = nilfs_iget_locked(sb, root, NILFS_IFILE_INO);
 198         if (unlikely(!ifile))
 199                 return -ENOMEM;
 200         if (!(ifile->i_state & I_NEW))
 201                 goto out;
 202
 203         err = nilfs_mdt_init(ifile, NILFS_MDT_GFP,
 204                              sizeof(struct nilfs_ifile_info));
 205         if (err)
 206                 goto failed;
 207
 208         err = nilfs_palloc_init_blockgroup(ifile, inode_size);
 209         if (err)
 210                 goto failed;
 211
 212         nilfs_palloc_setup_cache(ifile, &NILFS_IFILE_I(ifile)->palloc_cache);
 213
 214         err = nilfs_read_inode_common(ifile, raw_inode);
 215         if (err)
 216                 goto failed;
 217
 218         unlock_new_inode(ifile);
 219  out:
 220         *inodep = ifile;
 221         return 0;
 222  failed:
 223         iget_failed(ifile);
 224         return err;
 225 }