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, "bad inode number: %lu", (unsigned long)ino); 149 return -EINVAL; 150 } 151 152 err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh); 153 if (unlikely(err)) 154 nilfs_msg(sb, KERN_WARNING, "error %d reading inode: ino=%lu", 155 err, (unsigned long)ino); 156 return err; 157 } 158 159 /** 160 * nilfs_ifile_count_free_inodes - calculate free inodes count 161 * @ifile: ifile inode 162 * @nmaxinodes: current maximum of available inodes count [out] 163 * @nfreeinodes: free inodes count [out] 164 */ 165 int nilfs_ifile_count_free_inodes(struct inode *ifile, 166 u64 *nmaxinodes, u64 *nfreeinodes) 167 { 168 u64 nused; 169 int err; 170 171 *nmaxinodes = 0; 172 *nfreeinodes = 0; 173 174 nused = atomic64_read(&NILFS_I(ifile)->i_root->inodes_count); 175 err = nilfs_palloc_count_max_entries(ifile, nused, nmaxinodes); 176 if (likely(!err)) 177 *nfreeinodes = *nmaxinodes - nused; 178 return err; 179 } 180 181 /** 182 * nilfs_ifile_read - read or get ifile inode 183 * @sb: super block instance 184 * @root: root object 185 * @inode_size: size of an inode 186 * @raw_inode: on-disk ifile inode 187 * @inodep: buffer to store the inode 188 */ 189 int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root, 190 size_t inode_size, struct nilfs_inode *raw_inode, 191 struct inode **inodep) 192 { 193 struct inode *ifile; 194 int err; 195 196 ifile = nilfs_iget_locked(sb, root, NILFS_IFILE_INO); 197 if (unlikely(!ifile)) 198 return -ENOMEM; 199 if (!(ifile->i_state & I_NEW)) 200 goto out; 201 202 err = nilfs_mdt_init(ifile, NILFS_MDT_GFP, 203 sizeof(struct nilfs_ifile_info)); 204 if (err) 205 goto failed; 206 207 err = nilfs_palloc_init_blockgroup(ifile, inode_size); 208 if (err) 209 goto failed; 210 211 nilfs_palloc_setup_cache(ifile, &NILFS_IFILE_I(ifile)->palloc_cache); 212 213 err = nilfs_read_inode_common(ifile, raw_inode); 214 if (err) 215 goto failed; 216 217 unlock_new_inode(ifile); 218 out: 219 *inodep = ifile; 220 return 0; 221 failed: 222 iget_failed(ifile); 223 return err; 224 } 225