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