1 /* 2 * linux/fs/stat.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 */ 6 7 #include <linux/module.h> 8 #include <linux/mm.h> 9 #include <linux/errno.h> 10 #include <linux/file.h> 11 #include <linux/highuid.h> 12 #include <linux/fs.h> 13 #include <linux/namei.h> 14 #include <linux/security.h> 15 #include <linux/syscalls.h> 16 #include <linux/pagemap.h> 17 18 #include <asm/uaccess.h> 19 #include <asm/unistd.h> 20 21 void generic_fillattr(struct inode *inode, struct kstat *stat) 22 { 23 stat->dev = inode->i_sb->s_dev; 24 stat->ino = inode->i_ino; 25 stat->mode = inode->i_mode; 26 stat->nlink = inode->i_nlink; 27 stat->uid = inode->i_uid; 28 stat->gid = inode->i_gid; 29 stat->rdev = inode->i_rdev; 30 stat->atime = inode->i_atime; 31 stat->mtime = inode->i_mtime; 32 stat->ctime = inode->i_ctime; 33 stat->size = i_size_read(inode); 34 stat->blocks = inode->i_blocks; 35 stat->blksize = (1 << inode->i_blkbits); 36 } 37 38 EXPORT_SYMBOL(generic_fillattr); 39 40 int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 41 { 42 struct inode *inode = dentry->d_inode; 43 int retval; 44 45 retval = security_inode_getattr(mnt, dentry); 46 if (retval) 47 return retval; 48 49 if (inode->i_op->getattr) 50 return inode->i_op->getattr(mnt, dentry, stat); 51 52 generic_fillattr(inode, stat); 53 return 0; 54 } 55 56 EXPORT_SYMBOL(vfs_getattr); 57 58 int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat) 59 { 60 struct path path; 61 int error; 62 63 error = user_path_at(dfd, name, LOOKUP_FOLLOW, &path); 64 if (!error) { 65 error = vfs_getattr(path.mnt, path.dentry, stat); 66 path_put(&path); 67 } 68 return error; 69 } 70 71 int vfs_stat(char __user *name, struct kstat *stat) 72 { 73 return vfs_stat_fd(AT_FDCWD, name, stat); 74 } 75 76 EXPORT_SYMBOL(vfs_stat); 77 78 int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat) 79 { 80 struct path path; 81 int error; 82 83 error = user_path_at(dfd, name, 0, &path); 84 if (!error) { 85 error = vfs_getattr(path.mnt, path.dentry, stat); 86 path_put(&path); 87 } 88 return error; 89 } 90 91 int vfs_lstat(char __user *name, struct kstat *stat) 92 { 93 return vfs_lstat_fd(AT_FDCWD, name, stat); 94 } 95 96 EXPORT_SYMBOL(vfs_lstat); 97 98 int vfs_fstat(unsigned int fd, struct kstat *stat) 99 { 100 struct file *f = fget(fd); 101 int error = -EBADF; 102 103 if (f) { 104 error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat); 105 fput(f); 106 } 107 return error; 108 } 109 110 EXPORT_SYMBOL(vfs_fstat); 111 112 #ifdef __ARCH_WANT_OLD_STAT 113 114 /* 115 * For backward compatibility? Maybe this should be moved 116 * into arch/i386 instead? 117 */ 118 static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) 119 { 120 static int warncount = 5; 121 struct __old_kernel_stat tmp; 122 123 if (warncount > 0) { 124 warncount--; 125 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", 126 current->comm); 127 } else if (warncount < 0) { 128 /* it's laughable, but... */ 129 warncount = 0; 130 } 131 132 memset(&tmp, 0, sizeof(struct __old_kernel_stat)); 133 tmp.st_dev = old_encode_dev(stat->dev); 134 tmp.st_ino = stat->ino; 135 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) 136 return -EOVERFLOW; 137 tmp.st_mode = stat->mode; 138 tmp.st_nlink = stat->nlink; 139 if (tmp.st_nlink != stat->nlink) 140 return -EOVERFLOW; 141 SET_UID(tmp.st_uid, stat->uid); 142 SET_GID(tmp.st_gid, stat->gid); 143 tmp.st_rdev = old_encode_dev(stat->rdev); 144 #if BITS_PER_LONG == 32 145 if (stat->size > MAX_NON_LFS) 146 return -EOVERFLOW; 147 #endif 148 tmp.st_size = stat->size; 149 tmp.st_atime = stat->atime.tv_sec; 150 tmp.st_mtime = stat->mtime.tv_sec; 151 tmp.st_ctime = stat->ctime.tv_sec; 152 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; 153 } 154 155 asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf) 156 { 157 struct kstat stat; 158 int error = vfs_stat_fd(AT_FDCWD, filename, &stat); 159 160 if (!error) 161 error = cp_old_stat(&stat, statbuf); 162 163 return error; 164 } 165 asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf) 166 { 167 struct kstat stat; 168 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); 169 170 if (!error) 171 error = cp_old_stat(&stat, statbuf); 172 173 return error; 174 } 175 asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf) 176 { 177 struct kstat stat; 178 int error = vfs_fstat(fd, &stat); 179 180 if (!error) 181 error = cp_old_stat(&stat, statbuf); 182 183 return error; 184 } 185 186 #endif /* __ARCH_WANT_OLD_STAT */ 187 188 static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) 189 { 190 struct stat tmp; 191 192 #if BITS_PER_LONG == 32 193 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) 194 return -EOVERFLOW; 195 #else 196 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) 197 return -EOVERFLOW; 198 #endif 199 200 memset(&tmp, 0, sizeof(tmp)); 201 #if BITS_PER_LONG == 32 202 tmp.st_dev = old_encode_dev(stat->dev); 203 #else 204 tmp.st_dev = new_encode_dev(stat->dev); 205 #endif 206 tmp.st_ino = stat->ino; 207 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) 208 return -EOVERFLOW; 209 tmp.st_mode = stat->mode; 210 tmp.st_nlink = stat->nlink; 211 if (tmp.st_nlink != stat->nlink) 212 return -EOVERFLOW; 213 SET_UID(tmp.st_uid, stat->uid); 214 SET_GID(tmp.st_gid, stat->gid); 215 #if BITS_PER_LONG == 32 216 tmp.st_rdev = old_encode_dev(stat->rdev); 217 #else 218 tmp.st_rdev = new_encode_dev(stat->rdev); 219 #endif 220 #if BITS_PER_LONG == 32 221 if (stat->size > MAX_NON_LFS) 222 return -EOVERFLOW; 223 #endif 224 tmp.st_size = stat->size; 225 tmp.st_atime = stat->atime.tv_sec; 226 tmp.st_mtime = stat->mtime.tv_sec; 227 tmp.st_ctime = stat->ctime.tv_sec; 228 #ifdef STAT_HAVE_NSEC 229 tmp.st_atime_nsec = stat->atime.tv_nsec; 230 tmp.st_mtime_nsec = stat->mtime.tv_nsec; 231 tmp.st_ctime_nsec = stat->ctime.tv_nsec; 232 #endif 233 tmp.st_blocks = stat->blocks; 234 tmp.st_blksize = stat->blksize; 235 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; 236 } 237 238 asmlinkage long sys_newstat(char __user *filename, struct stat __user *statbuf) 239 { 240 struct kstat stat; 241 int error = vfs_stat_fd(AT_FDCWD, filename, &stat); 242 243 if (!error) 244 error = cp_new_stat(&stat, statbuf); 245 246 return error; 247 } 248 249 asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf) 250 { 251 struct kstat stat; 252 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); 253 254 if (!error) 255 error = cp_new_stat(&stat, statbuf); 256 257 return error; 258 } 259 260 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) 261 asmlinkage long sys_newfstatat(int dfd, char __user *filename, 262 struct stat __user *statbuf, int flag) 263 { 264 struct kstat stat; 265 int error = -EINVAL; 266 267 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) 268 goto out; 269 270 if (flag & AT_SYMLINK_NOFOLLOW) 271 error = vfs_lstat_fd(dfd, filename, &stat); 272 else 273 error = vfs_stat_fd(dfd, filename, &stat); 274 275 if (!error) 276 error = cp_new_stat(&stat, statbuf); 277 278 out: 279 return error; 280 } 281 #endif 282 283 asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf) 284 { 285 struct kstat stat; 286 int error = vfs_fstat(fd, &stat); 287 288 if (!error) 289 error = cp_new_stat(&stat, statbuf); 290 291 return error; 292 } 293 294 asmlinkage long sys_readlinkat(int dfd, const char __user *pathname, 295 char __user *buf, int bufsiz) 296 { 297 struct path path; 298 int error; 299 300 if (bufsiz <= 0) 301 return -EINVAL; 302 303 error = user_path_at(dfd, pathname, 0, &path); 304 if (!error) { 305 struct inode *inode = path.dentry->d_inode; 306 307 error = -EINVAL; 308 if (inode->i_op && inode->i_op->readlink) { 309 error = security_inode_readlink(path.dentry); 310 if (!error) { 311 touch_atime(path.mnt, path.dentry); 312 error = inode->i_op->readlink(path.dentry, 313 buf, bufsiz); 314 } 315 } 316 path_put(&path); 317 } 318 return error; 319 } 320 321 asmlinkage long sys_readlink(const char __user *path, char __user *buf, 322 int bufsiz) 323 { 324 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz); 325 } 326 327 328 /* ---------- LFS-64 ----------- */ 329 #ifdef __ARCH_WANT_STAT64 330 331 static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) 332 { 333 struct stat64 tmp; 334 335 memset(&tmp, 0, sizeof(struct stat64)); 336 #ifdef CONFIG_MIPS 337 /* mips has weird padding, so we don't get 64 bits there */ 338 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) 339 return -EOVERFLOW; 340 tmp.st_dev = new_encode_dev(stat->dev); 341 tmp.st_rdev = new_encode_dev(stat->rdev); 342 #else 343 tmp.st_dev = huge_encode_dev(stat->dev); 344 tmp.st_rdev = huge_encode_dev(stat->rdev); 345 #endif 346 tmp.st_ino = stat->ino; 347 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) 348 return -EOVERFLOW; 349 #ifdef STAT64_HAS_BROKEN_ST_INO 350 tmp.__st_ino = stat->ino; 351 #endif 352 tmp.st_mode = stat->mode; 353 tmp.st_nlink = stat->nlink; 354 tmp.st_uid = stat->uid; 355 tmp.st_gid = stat->gid; 356 tmp.st_atime = stat->atime.tv_sec; 357 tmp.st_atime_nsec = stat->atime.tv_nsec; 358 tmp.st_mtime = stat->mtime.tv_sec; 359 tmp.st_mtime_nsec = stat->mtime.tv_nsec; 360 tmp.st_ctime = stat->ctime.tv_sec; 361 tmp.st_ctime_nsec = stat->ctime.tv_nsec; 362 tmp.st_size = stat->size; 363 tmp.st_blocks = stat->blocks; 364 tmp.st_blksize = stat->blksize; 365 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; 366 } 367 368 asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf) 369 { 370 struct kstat stat; 371 int error = vfs_stat(filename, &stat); 372 373 if (!error) 374 error = cp_new_stat64(&stat, statbuf); 375 376 return error; 377 } 378 asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf) 379 { 380 struct kstat stat; 381 int error = vfs_lstat(filename, &stat); 382 383 if (!error) 384 error = cp_new_stat64(&stat, statbuf); 385 386 return error; 387 } 388 asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf) 389 { 390 struct kstat stat; 391 int error = vfs_fstat(fd, &stat); 392 393 if (!error) 394 error = cp_new_stat64(&stat, statbuf); 395 396 return error; 397 } 398 399 asmlinkage long sys_fstatat64(int dfd, char __user *filename, 400 struct stat64 __user *statbuf, int flag) 401 { 402 struct kstat stat; 403 int error = -EINVAL; 404 405 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) 406 goto out; 407 408 if (flag & AT_SYMLINK_NOFOLLOW) 409 error = vfs_lstat_fd(dfd, filename, &stat); 410 else 411 error = vfs_stat_fd(dfd, filename, &stat); 412 413 if (!error) 414 error = cp_new_stat64(&stat, statbuf); 415 416 out: 417 return error; 418 } 419 #endif /* __ARCH_WANT_STAT64 */ 420 421 void inode_add_bytes(struct inode *inode, loff_t bytes) 422 { 423 spin_lock(&inode->i_lock); 424 inode->i_blocks += bytes >> 9; 425 bytes &= 511; 426 inode->i_bytes += bytes; 427 if (inode->i_bytes >= 512) { 428 inode->i_blocks++; 429 inode->i_bytes -= 512; 430 } 431 spin_unlock(&inode->i_lock); 432 } 433 434 EXPORT_SYMBOL(inode_add_bytes); 435 436 void inode_sub_bytes(struct inode *inode, loff_t bytes) 437 { 438 spin_lock(&inode->i_lock); 439 inode->i_blocks -= bytes >> 9; 440 bytes &= 511; 441 if (inode->i_bytes < bytes) { 442 inode->i_blocks--; 443 inode->i_bytes += 512; 444 } 445 inode->i_bytes -= bytes; 446 spin_unlock(&inode->i_lock); 447 } 448 449 EXPORT_SYMBOL(inode_sub_bytes); 450 451 loff_t inode_get_bytes(struct inode *inode) 452 { 453 loff_t ret; 454 455 spin_lock(&inode->i_lock); 456 ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; 457 spin_unlock(&inode->i_lock); 458 return ret; 459 } 460 461 EXPORT_SYMBOL(inode_get_bytes); 462 463 void inode_set_bytes(struct inode *inode, loff_t bytes) 464 { 465 /* Caller is here responsible for sufficient locking 466 * (ie. inode->i_lock) */ 467 inode->i_blocks = bytes >> 9; 468 inode->i_bytes = bytes & 511; 469 } 470 471 EXPORT_SYMBOL(inode_set_bytes); 472