1 /* 2 * linux/fs/sysv/inode.c 3 * 4 * minix/inode.c 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * xenix/inode.c 8 * Copyright (C) 1992 Doug Evans 9 * 10 * coh/inode.c 11 * Copyright (C) 1993 Pascal Haible, Bruno Haible 12 * 13 * sysv/inode.c 14 * Copyright (C) 1993 Paul B. Monday 15 * 16 * sysv/inode.c 17 * Copyright (C) 1993 Bruno Haible 18 * Copyright (C) 1997, 1998 Krzysztof G. Baranowski 19 * 20 * This file contains code for allocating/freeing inodes and for read/writing 21 * the superblock. 22 */ 23 24 #include <linux/highuid.h> 25 #include <linux/slab.h> 26 #include <linux/init.h> 27 #include <linux/buffer_head.h> 28 #include <linux/vfs.h> 29 #include <linux/writeback.h> 30 #include <linux/namei.h> 31 #include <asm/byteorder.h> 32 #include "sysv.h" 33 34 static int sysv_sync_fs(struct super_block *sb, int wait) 35 { 36 struct sysv_sb_info *sbi = SYSV_SB(sb); 37 unsigned long time = get_seconds(), old_time; 38 39 mutex_lock(&sbi->s_lock); 40 41 /* 42 * If we are going to write out the super block, 43 * then attach current time stamp. 44 * But if the filesystem was marked clean, keep it clean. 45 */ 46 old_time = fs32_to_cpu(sbi, *sbi->s_sb_time); 47 if (sbi->s_type == FSTYPE_SYSV4) { 48 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time)) 49 *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time); 50 *sbi->s_sb_time = cpu_to_fs32(sbi, time); 51 mark_buffer_dirty(sbi->s_bh2); 52 } 53 54 mutex_unlock(&sbi->s_lock); 55 56 return 0; 57 } 58 59 static int sysv_remount(struct super_block *sb, int *flags, char *data) 60 { 61 struct sysv_sb_info *sbi = SYSV_SB(sb); 62 63 if (sbi->s_forced_ro) 64 *flags |= MS_RDONLY; 65 return 0; 66 } 67 68 static void sysv_put_super(struct super_block *sb) 69 { 70 struct sysv_sb_info *sbi = SYSV_SB(sb); 71 72 if (!(sb->s_flags & MS_RDONLY)) { 73 /* XXX ext2 also updates the state here */ 74 mark_buffer_dirty(sbi->s_bh1); 75 if (sbi->s_bh1 != sbi->s_bh2) 76 mark_buffer_dirty(sbi->s_bh2); 77 } 78 79 brelse(sbi->s_bh1); 80 if (sbi->s_bh1 != sbi->s_bh2) 81 brelse(sbi->s_bh2); 82 83 kfree(sbi); 84 } 85 86 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf) 87 { 88 struct super_block *sb = dentry->d_sb; 89 struct sysv_sb_info *sbi = SYSV_SB(sb); 90 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 91 92 buf->f_type = sb->s_magic; 93 buf->f_bsize = sb->s_blocksize; 94 buf->f_blocks = sbi->s_ndatazones; 95 buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb); 96 buf->f_files = sbi->s_ninodes; 97 buf->f_ffree = sysv_count_free_inodes(sb); 98 buf->f_namelen = SYSV_NAMELEN; 99 buf->f_fsid.val[0] = (u32)id; 100 buf->f_fsid.val[1] = (u32)(id >> 32); 101 return 0; 102 } 103 104 /* 105 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32 106 */ 107 static inline void read3byte(struct sysv_sb_info *sbi, 108 unsigned char * from, unsigned char * to) 109 { 110 if (sbi->s_bytesex == BYTESEX_PDP) { 111 to[0] = from[0]; 112 to[1] = 0; 113 to[2] = from[1]; 114 to[3] = from[2]; 115 } else if (sbi->s_bytesex == BYTESEX_LE) { 116 to[0] = from[0]; 117 to[1] = from[1]; 118 to[2] = from[2]; 119 to[3] = 0; 120 } else { 121 to[0] = 0; 122 to[1] = from[0]; 123 to[2] = from[1]; 124 to[3] = from[2]; 125 } 126 } 127 128 static inline void write3byte(struct sysv_sb_info *sbi, 129 unsigned char * from, unsigned char * to) 130 { 131 if (sbi->s_bytesex == BYTESEX_PDP) { 132 to[0] = from[0]; 133 to[1] = from[2]; 134 to[2] = from[3]; 135 } else if (sbi->s_bytesex == BYTESEX_LE) { 136 to[0] = from[0]; 137 to[1] = from[1]; 138 to[2] = from[2]; 139 } else { 140 to[0] = from[1]; 141 to[1] = from[2]; 142 to[2] = from[3]; 143 } 144 } 145 146 static const struct inode_operations sysv_symlink_inode_operations = { 147 .readlink = generic_readlink, 148 .follow_link = page_follow_link_light, 149 .put_link = page_put_link, 150 .getattr = sysv_getattr, 151 }; 152 153 void sysv_set_inode(struct inode *inode, dev_t rdev) 154 { 155 if (S_ISREG(inode->i_mode)) { 156 inode->i_op = &sysv_file_inode_operations; 157 inode->i_fop = &sysv_file_operations; 158 inode->i_mapping->a_ops = &sysv_aops; 159 } else if (S_ISDIR(inode->i_mode)) { 160 inode->i_op = &sysv_dir_inode_operations; 161 inode->i_fop = &sysv_dir_operations; 162 inode->i_mapping->a_ops = &sysv_aops; 163 } else if (S_ISLNK(inode->i_mode)) { 164 if (inode->i_blocks) { 165 inode->i_op = &sysv_symlink_inode_operations; 166 inode->i_mapping->a_ops = &sysv_aops; 167 } else { 168 inode->i_op = &sysv_fast_symlink_inode_operations; 169 nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size, 170 sizeof(SYSV_I(inode)->i_data) - 1); 171 } 172 } else 173 init_special_inode(inode, inode->i_mode, rdev); 174 } 175 176 struct inode *sysv_iget(struct super_block *sb, unsigned int ino) 177 { 178 struct sysv_sb_info * sbi = SYSV_SB(sb); 179 struct buffer_head * bh; 180 struct sysv_inode * raw_inode; 181 struct sysv_inode_info * si; 182 struct inode *inode; 183 unsigned int block; 184 185 if (!ino || ino > sbi->s_ninodes) { 186 printk("Bad inode number on dev %s: %d is out of range\n", 187 sb->s_id, ino); 188 return ERR_PTR(-EIO); 189 } 190 191 inode = iget_locked(sb, ino); 192 if (!inode) 193 return ERR_PTR(-ENOMEM); 194 if (!(inode->i_state & I_NEW)) 195 return inode; 196 197 raw_inode = sysv_raw_inode(sb, ino, &bh); 198 if (!raw_inode) { 199 printk("Major problem: unable to read inode from dev %s\n", 200 inode->i_sb->s_id); 201 goto bad_inode; 202 } 203 /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */ 204 inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode); 205 i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid)); 206 i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid)); 207 set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink)); 208 inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size); 209 inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime); 210 inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime); 211 inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime); 212 inode->i_ctime.tv_nsec = 0; 213 inode->i_atime.tv_nsec = 0; 214 inode->i_mtime.tv_nsec = 0; 215 inode->i_blocks = 0; 216 217 si = SYSV_I(inode); 218 for (block = 0; block < 10+1+1+1; block++) 219 read3byte(sbi, &raw_inode->i_data[3*block], 220 (u8 *)&si->i_data[block]); 221 brelse(bh); 222 si->i_dir_start_lookup = 0; 223 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) 224 sysv_set_inode(inode, 225 old_decode_dev(fs32_to_cpu(sbi, si->i_data[0]))); 226 else 227 sysv_set_inode(inode, 0); 228 unlock_new_inode(inode); 229 return inode; 230 231 bad_inode: 232 iget_failed(inode); 233 return ERR_PTR(-EIO); 234 } 235 236 static int __sysv_write_inode(struct inode *inode, int wait) 237 { 238 struct super_block * sb = inode->i_sb; 239 struct sysv_sb_info * sbi = SYSV_SB(sb); 240 struct buffer_head * bh; 241 struct sysv_inode * raw_inode; 242 struct sysv_inode_info * si; 243 unsigned int ino, block; 244 int err = 0; 245 246 ino = inode->i_ino; 247 if (!ino || ino > sbi->s_ninodes) { 248 printk("Bad inode number on dev %s: %d is out of range\n", 249 inode->i_sb->s_id, ino); 250 return -EIO; 251 } 252 raw_inode = sysv_raw_inode(sb, ino, &bh); 253 if (!raw_inode) { 254 printk("unable to read i-node block\n"); 255 return -EIO; 256 } 257 258 raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode); 259 raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode))); 260 raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode))); 261 raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink); 262 raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size); 263 raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec); 264 raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec); 265 raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec); 266 267 si = SYSV_I(inode); 268 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) 269 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev)); 270 for (block = 0; block < 10+1+1+1; block++) 271 write3byte(sbi, (u8 *)&si->i_data[block], 272 &raw_inode->i_data[3*block]); 273 mark_buffer_dirty(bh); 274 if (wait) { 275 sync_dirty_buffer(bh); 276 if (buffer_req(bh) && !buffer_uptodate(bh)) { 277 printk ("IO error syncing sysv inode [%s:%08x]\n", 278 sb->s_id, ino); 279 err = -EIO; 280 } 281 } 282 brelse(bh); 283 return 0; 284 } 285 286 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc) 287 { 288 return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 289 } 290 291 int sysv_sync_inode(struct inode *inode) 292 { 293 return __sysv_write_inode(inode, 1); 294 } 295 296 static void sysv_evict_inode(struct inode *inode) 297 { 298 truncate_inode_pages(&inode->i_data, 0); 299 if (!inode->i_nlink) { 300 inode->i_size = 0; 301 sysv_truncate(inode); 302 } 303 invalidate_inode_buffers(inode); 304 clear_inode(inode); 305 if (!inode->i_nlink) 306 sysv_free_inode(inode); 307 } 308 309 static struct kmem_cache *sysv_inode_cachep; 310 311 static struct inode *sysv_alloc_inode(struct super_block *sb) 312 { 313 struct sysv_inode_info *si; 314 315 si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL); 316 if (!si) 317 return NULL; 318 return &si->vfs_inode; 319 } 320 321 static void sysv_i_callback(struct rcu_head *head) 322 { 323 struct inode *inode = container_of(head, struct inode, i_rcu); 324 kmem_cache_free(sysv_inode_cachep, SYSV_I(inode)); 325 } 326 327 static void sysv_destroy_inode(struct inode *inode) 328 { 329 call_rcu(&inode->i_rcu, sysv_i_callback); 330 } 331 332 static void init_once(void *p) 333 { 334 struct sysv_inode_info *si = (struct sysv_inode_info *)p; 335 336 inode_init_once(&si->vfs_inode); 337 } 338 339 const struct super_operations sysv_sops = { 340 .alloc_inode = sysv_alloc_inode, 341 .destroy_inode = sysv_destroy_inode, 342 .write_inode = sysv_write_inode, 343 .evict_inode = sysv_evict_inode, 344 .put_super = sysv_put_super, 345 .sync_fs = sysv_sync_fs, 346 .remount_fs = sysv_remount, 347 .statfs = sysv_statfs, 348 }; 349 350 int __init sysv_init_icache(void) 351 { 352 sysv_inode_cachep = kmem_cache_create("sysv_inode_cache", 353 sizeof(struct sysv_inode_info), 0, 354 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 355 init_once); 356 if (!sysv_inode_cachep) 357 return -ENOMEM; 358 return 0; 359 } 360 361 void sysv_destroy_icache(void) 362 { 363 /* 364 * Make sure all delayed rcu free inodes are flushed before we 365 * destroy cache. 366 */ 367 rcu_barrier(); 368 kmem_cache_destroy(sysv_inode_cachep); 369 } 370