1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/sysv/inode.c 4 * 5 * minix/inode.c 6 * Copyright (C) 1991, 1992 Linus Torvalds 7 * 8 * xenix/inode.c 9 * Copyright (C) 1992 Doug Evans 10 * 11 * coh/inode.c 12 * Copyright (C) 1993 Pascal Haible, Bruno Haible 13 * 14 * sysv/inode.c 15 * Copyright (C) 1993 Paul B. Monday 16 * 17 * sysv/inode.c 18 * Copyright (C) 1993 Bruno Haible 19 * Copyright (C) 1997, 1998 Krzysztof G. Baranowski 20 * 21 * This file contains code for allocating/freeing inodes and for read/writing 22 * the superblock. 23 */ 24 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 <linux/writeback.h> 31 #include <linux/namei.h> 32 #include <asm/byteorder.h> 33 #include "sysv.h" 34 35 static int sysv_sync_fs(struct super_block *sb, int wait) 36 { 37 struct sysv_sb_info *sbi = SYSV_SB(sb); 38 u32 time = (u32)ktime_get_real_seconds(), old_time; 39 40 mutex_lock(&sbi->s_lock); 41 42 /* 43 * If we are going to write out the super block, 44 * then attach current time stamp. 45 * But if the filesystem was marked clean, keep it clean. 46 */ 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, 0x7c269d38u - old_time)) 50 *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38u - time); 51 *sbi->s_sb_time = cpu_to_fs32(sbi, time); 52 mark_buffer_dirty(sbi->s_bh2); 53 } 54 55 mutex_unlock(&sbi->s_lock); 56 57 return 0; 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 64 sync_filesystem(sb); 65 if (sbi->s_forced_ro) 66 *flags |= SB_RDONLY; 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_rdonly(sb)) { 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 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 93 94 buf->f_type = sb->s_magic; 95 buf->f_bsize = sb->s_blocksize; 96 buf->f_blocks = sbi->s_ndatazones; 97 buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb); 98 buf->f_files = sbi->s_ninodes; 99 buf->f_ffree = sysv_count_free_inodes(sb); 100 buf->f_namelen = SYSV_NAMELEN; 101 buf->f_fsid.val[0] = (u32)id; 102 buf->f_fsid.val[1] = (u32)(id >> 32); 103 return 0; 104 } 105 106 /* 107 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32 108 */ 109 static inline void read3byte(struct sysv_sb_info *sbi, 110 unsigned char * from, unsigned char * to) 111 { 112 if (sbi->s_bytesex == BYTESEX_PDP) { 113 to[0] = from[0]; 114 to[1] = 0; 115 to[2] = from[1]; 116 to[3] = from[2]; 117 } else if (sbi->s_bytesex == BYTESEX_LE) { 118 to[0] = from[0]; 119 to[1] = from[1]; 120 to[2] = from[2]; 121 to[3] = 0; 122 } else { 123 to[0] = 0; 124 to[1] = from[0]; 125 to[2] = from[1]; 126 to[3] = from[2]; 127 } 128 } 129 130 static inline void write3byte(struct sysv_sb_info *sbi, 131 unsigned char * from, unsigned char * to) 132 { 133 if (sbi->s_bytesex == BYTESEX_PDP) { 134 to[0] = from[0]; 135 to[1] = from[2]; 136 to[2] = from[3]; 137 } else if (sbi->s_bytesex == BYTESEX_LE) { 138 to[0] = from[0]; 139 to[1] = from[1]; 140 to[2] = from[2]; 141 } else { 142 to[0] = from[1]; 143 to[1] = from[2]; 144 to[2] = from[3]; 145 } 146 } 147 148 static const struct inode_operations sysv_symlink_inode_operations = { 149 .get_link = page_get_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 inode->i_op = &sysv_symlink_inode_operations; 165 inode_nohighmem(inode); 166 inode->i_mapping->a_ops = &sysv_aops; 167 } else 168 init_special_inode(inode, inode->i_mode, rdev); 169 } 170 171 struct inode *sysv_iget(struct super_block *sb, unsigned int ino) 172 { 173 struct sysv_sb_info * sbi = SYSV_SB(sb); 174 struct buffer_head * bh; 175 struct sysv_inode * raw_inode; 176 struct sysv_inode_info * si; 177 struct inode *inode; 178 unsigned int block; 179 180 if (!ino || ino > sbi->s_ninodes) { 181 printk("Bad inode number on dev %s: %d is out of range\n", 182 sb->s_id, ino); 183 return ERR_PTR(-EIO); 184 } 185 186 inode = iget_locked(sb, ino); 187 if (!inode) 188 return ERR_PTR(-ENOMEM); 189 if (!(inode->i_state & I_NEW)) 190 return inode; 191 192 raw_inode = sysv_raw_inode(sb, ino, &bh); 193 if (!raw_inode) { 194 printk("Major problem: unable to read inode from dev %s\n", 195 inode->i_sb->s_id); 196 goto bad_inode; 197 } 198 /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */ 199 inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode); 200 i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid)); 201 i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid)); 202 set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink)); 203 inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size); 204 inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime); 205 inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime); 206 inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime); 207 inode->i_ctime.tv_nsec = 0; 208 inode->i_atime.tv_nsec = 0; 209 inode->i_mtime.tv_nsec = 0; 210 inode->i_blocks = 0; 211 212 si = SYSV_I(inode); 213 for (block = 0; block < 10+1+1+1; block++) 214 read3byte(sbi, &raw_inode->i_data[3*block], 215 (u8 *)&si->i_data[block]); 216 brelse(bh); 217 si->i_dir_start_lookup = 0; 218 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) 219 sysv_set_inode(inode, 220 old_decode_dev(fs32_to_cpu(sbi, si->i_data[0]))); 221 else 222 sysv_set_inode(inode, 0); 223 unlock_new_inode(inode); 224 return inode; 225 226 bad_inode: 227 iget_failed(inode); 228 return ERR_PTR(-EIO); 229 } 230 231 static int __sysv_write_inode(struct inode *inode, int wait) 232 { 233 struct super_block * sb = inode->i_sb; 234 struct sysv_sb_info * sbi = SYSV_SB(sb); 235 struct buffer_head * bh; 236 struct sysv_inode * raw_inode; 237 struct sysv_inode_info * si; 238 unsigned int ino, block; 239 int err = 0; 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 -EIO; 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 -EIO; 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(i_uid_read(inode))); 255 raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode))); 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 if (wait) { 270 sync_dirty_buffer(bh); 271 if (buffer_req(bh) && !buffer_uptodate(bh)) { 272 printk ("IO error syncing sysv inode [%s:%08x]\n", 273 sb->s_id, ino); 274 err = -EIO; 275 } 276 } 277 brelse(bh); 278 return 0; 279 } 280 281 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc) 282 { 283 return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 284 } 285 286 int sysv_sync_inode(struct inode *inode) 287 { 288 return __sysv_write_inode(inode, 1); 289 } 290 291 static void sysv_evict_inode(struct inode *inode) 292 { 293 truncate_inode_pages_final(&inode->i_data); 294 if (!inode->i_nlink) { 295 inode->i_size = 0; 296 sysv_truncate(inode); 297 } 298 invalidate_inode_buffers(inode); 299 clear_inode(inode); 300 if (!inode->i_nlink) 301 sysv_free_inode(inode); 302 } 303 304 static struct kmem_cache *sysv_inode_cachep; 305 306 static struct inode *sysv_alloc_inode(struct super_block *sb) 307 { 308 struct sysv_inode_info *si; 309 310 si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL); 311 if (!si) 312 return NULL; 313 return &si->vfs_inode; 314 } 315 316 static void sysv_i_callback(struct rcu_head *head) 317 { 318 struct inode *inode = container_of(head, struct inode, i_rcu); 319 kmem_cache_free(sysv_inode_cachep, SYSV_I(inode)); 320 } 321 322 static void sysv_destroy_inode(struct inode *inode) 323 { 324 call_rcu(&inode->i_rcu, sysv_i_callback); 325 } 326 327 static void init_once(void *p) 328 { 329 struct sysv_inode_info *si = (struct sysv_inode_info *)p; 330 331 inode_init_once(&si->vfs_inode); 332 } 333 334 const struct super_operations sysv_sops = { 335 .alloc_inode = sysv_alloc_inode, 336 .destroy_inode = sysv_destroy_inode, 337 .write_inode = sysv_write_inode, 338 .evict_inode = sysv_evict_inode, 339 .put_super = sysv_put_super, 340 .sync_fs = sysv_sync_fs, 341 .remount_fs = sysv_remount, 342 .statfs = sysv_statfs, 343 }; 344 345 int __init sysv_init_icache(void) 346 { 347 sysv_inode_cachep = kmem_cache_create("sysv_inode_cache", 348 sizeof(struct sysv_inode_info), 0, 349 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT, 350 init_once); 351 if (!sysv_inode_cachep) 352 return -ENOMEM; 353 return 0; 354 } 355 356 void sysv_destroy_icache(void) 357 { 358 /* 359 * Make sure all delayed rcu free inodes are flushed before we 360 * destroy cache. 361 */ 362 rcu_barrier(); 363 kmem_cache_destroy(sysv_inode_cachep); 364 } 365