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 lock_super(sb); 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 sb->s_dirt = 0; 47 old_time = fs32_to_cpu(sbi, *sbi->s_sb_time); 48 if (sbi->s_type == FSTYPE_SYSV4) { 49 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time)) 50 *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time); 51 *sbi->s_sb_time = cpu_to_fs32(sbi, time); 52 mark_buffer_dirty(sbi->s_bh2); 53 } 54 55 unlock_super(sb); 56 57 return 0; 58 } 59 60 static void sysv_write_super(struct super_block *sb) 61 { 62 if (!(sb->s_flags & MS_RDONLY)) 63 sysv_sync_fs(sb, 1); 64 else 65 sb->s_dirt = 0; 66 } 67 68 static int sysv_remount(struct super_block *sb, int *flags, char *data) 69 { 70 struct sysv_sb_info *sbi = SYSV_SB(sb); 71 lock_super(sb); 72 if (sbi->s_forced_ro) 73 *flags |= MS_RDONLY; 74 if (*flags & MS_RDONLY) 75 sysv_write_super(sb); 76 unlock_super(sb); 77 return 0; 78 } 79 80 static void sysv_put_super(struct super_block *sb) 81 { 82 struct sysv_sb_info *sbi = SYSV_SB(sb); 83 84 if (sb->s_dirt) 85 sysv_write_super(sb); 86 87 if (!(sb->s_flags & MS_RDONLY)) { 88 /* XXX ext2 also updates the state here */ 89 mark_buffer_dirty(sbi->s_bh1); 90 if (sbi->s_bh1 != sbi->s_bh2) 91 mark_buffer_dirty(sbi->s_bh2); 92 } 93 94 brelse(sbi->s_bh1); 95 if (sbi->s_bh1 != sbi->s_bh2) 96 brelse(sbi->s_bh2); 97 98 kfree(sbi); 99 } 100 101 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf) 102 { 103 struct super_block *sb = dentry->d_sb; 104 struct sysv_sb_info *sbi = SYSV_SB(sb); 105 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 106 107 buf->f_type = sb->s_magic; 108 buf->f_bsize = sb->s_blocksize; 109 buf->f_blocks = sbi->s_ndatazones; 110 buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb); 111 buf->f_files = sbi->s_ninodes; 112 buf->f_ffree = sysv_count_free_inodes(sb); 113 buf->f_namelen = SYSV_NAMELEN; 114 buf->f_fsid.val[0] = (u32)id; 115 buf->f_fsid.val[1] = (u32)(id >> 32); 116 return 0; 117 } 118 119 /* 120 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32 121 */ 122 static inline void read3byte(struct sysv_sb_info *sbi, 123 unsigned char * from, unsigned char * to) 124 { 125 if (sbi->s_bytesex == BYTESEX_PDP) { 126 to[0] = from[0]; 127 to[1] = 0; 128 to[2] = from[1]; 129 to[3] = from[2]; 130 } else if (sbi->s_bytesex == BYTESEX_LE) { 131 to[0] = from[0]; 132 to[1] = from[1]; 133 to[2] = from[2]; 134 to[3] = 0; 135 } else { 136 to[0] = 0; 137 to[1] = from[0]; 138 to[2] = from[1]; 139 to[3] = from[2]; 140 } 141 } 142 143 static inline void write3byte(struct sysv_sb_info *sbi, 144 unsigned char * from, unsigned char * to) 145 { 146 if (sbi->s_bytesex == BYTESEX_PDP) { 147 to[0] = from[0]; 148 to[1] = from[2]; 149 to[2] = from[3]; 150 } else if (sbi->s_bytesex == BYTESEX_LE) { 151 to[0] = from[0]; 152 to[1] = from[1]; 153 to[2] = from[2]; 154 } else { 155 to[0] = from[1]; 156 to[1] = from[2]; 157 to[2] = from[3]; 158 } 159 } 160 161 static const struct inode_operations sysv_symlink_inode_operations = { 162 .readlink = generic_readlink, 163 .follow_link = page_follow_link_light, 164 .put_link = page_put_link, 165 .getattr = sysv_getattr, 166 }; 167 168 void sysv_set_inode(struct inode *inode, dev_t rdev) 169 { 170 if (S_ISREG(inode->i_mode)) { 171 inode->i_op = &sysv_file_inode_operations; 172 inode->i_fop = &sysv_file_operations; 173 inode->i_mapping->a_ops = &sysv_aops; 174 } else if (S_ISDIR(inode->i_mode)) { 175 inode->i_op = &sysv_dir_inode_operations; 176 inode->i_fop = &sysv_dir_operations; 177 inode->i_mapping->a_ops = &sysv_aops; 178 } else if (S_ISLNK(inode->i_mode)) { 179 if (inode->i_blocks) { 180 inode->i_op = &sysv_symlink_inode_operations; 181 inode->i_mapping->a_ops = &sysv_aops; 182 } else { 183 inode->i_op = &sysv_fast_symlink_inode_operations; 184 nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size, 185 sizeof(SYSV_I(inode)->i_data) - 1); 186 } 187 } else 188 init_special_inode(inode, inode->i_mode, rdev); 189 } 190 191 struct inode *sysv_iget(struct super_block *sb, unsigned int ino) 192 { 193 struct sysv_sb_info * sbi = SYSV_SB(sb); 194 struct buffer_head * bh; 195 struct sysv_inode * raw_inode; 196 struct sysv_inode_info * si; 197 struct inode *inode; 198 unsigned int block; 199 200 if (!ino || ino > sbi->s_ninodes) { 201 printk("Bad inode number on dev %s: %d is out of range\n", 202 sb->s_id, ino); 203 return ERR_PTR(-EIO); 204 } 205 206 inode = iget_locked(sb, ino); 207 if (!inode) 208 return ERR_PTR(-ENOMEM); 209 if (!(inode->i_state & I_NEW)) 210 return inode; 211 212 raw_inode = sysv_raw_inode(sb, ino, &bh); 213 if (!raw_inode) { 214 printk("Major problem: unable to read inode from dev %s\n", 215 inode->i_sb->s_id); 216 goto bad_inode; 217 } 218 /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */ 219 inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode); 220 inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid); 221 inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid); 222 set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink)); 223 inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size); 224 inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime); 225 inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime); 226 inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime); 227 inode->i_ctime.tv_nsec = 0; 228 inode->i_atime.tv_nsec = 0; 229 inode->i_mtime.tv_nsec = 0; 230 inode->i_blocks = 0; 231 232 si = SYSV_I(inode); 233 for (block = 0; block < 10+1+1+1; block++) 234 read3byte(sbi, &raw_inode->i_data[3*block], 235 (u8 *)&si->i_data[block]); 236 brelse(bh); 237 si->i_dir_start_lookup = 0; 238 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) 239 sysv_set_inode(inode, 240 old_decode_dev(fs32_to_cpu(sbi, si->i_data[0]))); 241 else 242 sysv_set_inode(inode, 0); 243 unlock_new_inode(inode); 244 return inode; 245 246 bad_inode: 247 iget_failed(inode); 248 return ERR_PTR(-EIO); 249 } 250 251 static int __sysv_write_inode(struct inode *inode, int wait) 252 { 253 struct super_block * sb = inode->i_sb; 254 struct sysv_sb_info * sbi = SYSV_SB(sb); 255 struct buffer_head * bh; 256 struct sysv_inode * raw_inode; 257 struct sysv_inode_info * si; 258 unsigned int ino, block; 259 int err = 0; 260 261 ino = inode->i_ino; 262 if (!ino || ino > sbi->s_ninodes) { 263 printk("Bad inode number on dev %s: %d is out of range\n", 264 inode->i_sb->s_id, ino); 265 return -EIO; 266 } 267 raw_inode = sysv_raw_inode(sb, ino, &bh); 268 if (!raw_inode) { 269 printk("unable to read i-node block\n"); 270 return -EIO; 271 } 272 273 raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode); 274 raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid)); 275 raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid)); 276 raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink); 277 raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size); 278 raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec); 279 raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec); 280 raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec); 281 282 si = SYSV_I(inode); 283 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) 284 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev)); 285 for (block = 0; block < 10+1+1+1; block++) 286 write3byte(sbi, (u8 *)&si->i_data[block], 287 &raw_inode->i_data[3*block]); 288 mark_buffer_dirty(bh); 289 if (wait) { 290 sync_dirty_buffer(bh); 291 if (buffer_req(bh) && !buffer_uptodate(bh)) { 292 printk ("IO error syncing sysv inode [%s:%08x]\n", 293 sb->s_id, ino); 294 err = -EIO; 295 } 296 } 297 brelse(bh); 298 return 0; 299 } 300 301 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc) 302 { 303 return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 304 } 305 306 int sysv_sync_inode(struct inode *inode) 307 { 308 return __sysv_write_inode(inode, 1); 309 } 310 311 static void sysv_evict_inode(struct inode *inode) 312 { 313 truncate_inode_pages(&inode->i_data, 0); 314 if (!inode->i_nlink) { 315 inode->i_size = 0; 316 sysv_truncate(inode); 317 } 318 invalidate_inode_buffers(inode); 319 end_writeback(inode); 320 if (!inode->i_nlink) 321 sysv_free_inode(inode); 322 } 323 324 static struct kmem_cache *sysv_inode_cachep; 325 326 static struct inode *sysv_alloc_inode(struct super_block *sb) 327 { 328 struct sysv_inode_info *si; 329 330 si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL); 331 if (!si) 332 return NULL; 333 return &si->vfs_inode; 334 } 335 336 static void sysv_i_callback(struct rcu_head *head) 337 { 338 struct inode *inode = container_of(head, struct inode, i_rcu); 339 INIT_LIST_HEAD(&inode->i_dentry); 340 kmem_cache_free(sysv_inode_cachep, SYSV_I(inode)); 341 } 342 343 static void sysv_destroy_inode(struct inode *inode) 344 { 345 call_rcu(&inode->i_rcu, sysv_i_callback); 346 } 347 348 static void init_once(void *p) 349 { 350 struct sysv_inode_info *si = (struct sysv_inode_info *)p; 351 352 inode_init_once(&si->vfs_inode); 353 } 354 355 const struct super_operations sysv_sops = { 356 .alloc_inode = sysv_alloc_inode, 357 .destroy_inode = sysv_destroy_inode, 358 .write_inode = sysv_write_inode, 359 .evict_inode = sysv_evict_inode, 360 .put_super = sysv_put_super, 361 .write_super = sysv_write_super, 362 .sync_fs = sysv_sync_fs, 363 .remount_fs = sysv_remount, 364 .statfs = sysv_statfs, 365 }; 366 367 int __init sysv_init_icache(void) 368 { 369 sysv_inode_cachep = kmem_cache_create("sysv_inode_cache", 370 sizeof(struct sysv_inode_info), 0, 371 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 372 init_once); 373 if (!sysv_inode_cachep) 374 return -ENOMEM; 375 return 0; 376 } 377 378 void sysv_destroy_icache(void) 379 { 380 kmem_cache_destroy(sysv_inode_cachep); 381 } 382