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