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 21void 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 38EXPORT_SYMBOL(generic_fillattr); 39 40int 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 56EXPORT_SYMBOL(vfs_getattr); 57 58int vfs_fstat(unsigned int fd, struct kstat *stat) 59{ 60 struct file *f = fget(fd); 61 int error = -EBADF; 62 63 if (f) { 64 error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat); 65 fput(f); 66 } 67 return error; 68} 69EXPORT_SYMBOL(vfs_fstat); 70 71int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, 72 int flag) 73{ 74 struct path path; 75 int error = -EINVAL; 76 int lookup_flags = 0; 77 78 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) 79 goto out; 80 81 if (!(flag & AT_SYMLINK_NOFOLLOW)) 82 lookup_flags |= LOOKUP_FOLLOW; 83 84 error = user_path_at(dfd, filename, lookup_flags, &path); 85 if (error) 86 goto out; 87 88 error = vfs_getattr(path.mnt, path.dentry, stat); 89 path_put(&path); 90out: 91 return error; 92} 93EXPORT_SYMBOL(vfs_fstatat); 94 95int vfs_stat(const char __user *name, struct kstat *stat) 96{ 97 return vfs_fstatat(AT_FDCWD, name, stat, 0); 98} 99EXPORT_SYMBOL(vfs_stat); 100 101int vfs_lstat(const char __user *name, struct kstat *stat) 102{ 103 return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); 104} 105EXPORT_SYMBOL(vfs_lstat); 106 107 108#ifdef __ARCH_WANT_OLD_STAT 109 110/* 111 * For backward compatibility? Maybe this should be moved 112 * into arch/i386 instead? 113 */ 114static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) 115{ 116 static int warncount = 5; 117 struct __old_kernel_stat tmp; 118 119 if (warncount > 0) { 120 warncount--; 121 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", 122 current->comm); 123 } else if (warncount < 0) { 124 /* it's laughable, but... */ 125 warncount = 0; 126 } 127 128 memset(&tmp, 0, sizeof(struct __old_kernel_stat)); 129 tmp.st_dev = old_encode_dev(stat->dev); 130 tmp.st_ino = stat->ino; 131 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) 132 return -EOVERFLOW; 133 tmp.st_mode = stat->mode; 134 tmp.st_nlink = stat->nlink; 135 if (tmp.st_nlink != stat->nlink) 136 return -EOVERFLOW; 137 SET_UID(tmp.st_uid, stat->uid); 138 SET_GID(tmp.st_gid, stat->gid); 139 tmp.st_rdev = old_encode_dev(stat->rdev); 140 /* Foxconn modified start pling 12/04/2009 */ 141 /* Remove large file size limitation */ 142#if (!defined SAMBA_ENABLE) 143#if BITS_PER_LONG == 32 144 if (stat->size > MAX_NON_LFS) 145 return -EOVERFLOW; 146#endif 147#endif 148 /* Foxconn modified end pling 12/04/2009 */ 149 tmp.st_size = stat->size; 150 tmp.st_atime = stat->atime.tv_sec; 151 tmp.st_mtime = stat->mtime.tv_sec; 152 tmp.st_ctime = stat->ctime.tv_sec; 153 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; 154} 155 156SYSCALL_DEFINE2(stat, const char __user *, filename, 157 struct __old_kernel_stat __user *, statbuf) 158{ 159 struct kstat stat; 160 int error; 161 162 error = vfs_stat(filename, &stat); 163 if (error) 164 return error; 165 166 return cp_old_stat(&stat, statbuf); 167} 168 169SYSCALL_DEFINE2(lstat, const char __user *, filename, 170 struct __old_kernel_stat __user *, statbuf) 171{ 172 struct kstat stat; 173 int error; 174 175 error = vfs_lstat(filename, &stat); 176 if (error) 177 return error; 178 179 return cp_old_stat(&stat, statbuf); 180} 181 182SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) 183{ 184 struct kstat stat; 185 int error = vfs_fstat(fd, &stat); 186 187 if (!error) 188 error = cp_old_stat(&stat, statbuf); 189 190 return error; 191} 192 193#endif /* __ARCH_WANT_OLD_STAT */ 194 195static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) 196{ 197 struct stat tmp; 198 199#if BITS_PER_LONG == 32 200 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) 201 return -EOVERFLOW; 202#else 203 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) 204 return -EOVERFLOW; 205#endif 206 207 memset(&tmp, 0, sizeof(tmp)); 208#if BITS_PER_LONG == 32 209 tmp.st_dev = old_encode_dev(stat->dev); 210#else 211 tmp.st_dev = new_encode_dev(stat->dev); 212#endif 213 tmp.st_ino = stat->ino; 214 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) 215 return -EOVERFLOW; 216 tmp.st_mode = stat->mode; 217 tmp.st_nlink = stat->nlink; 218 if (tmp.st_nlink != stat->nlink) 219 return -EOVERFLOW; 220 SET_UID(tmp.st_uid, stat->uid); 221 SET_GID(tmp.st_gid, stat->gid); 222#if BITS_PER_LONG == 32 223 tmp.st_rdev = old_encode_dev(stat->rdev); 224#else 225 tmp.st_rdev = new_encode_dev(stat->rdev); 226#endif 227 /* Foxconn modified start pling 12/04/2009 */ 228 /* Remove large file size limitation */ 229#if (!defined SAMBA_ENABLE) 230#if BITS_PER_LONG == 32 231 if (stat->size > MAX_NON_LFS) 232 return -EOVERFLOW; 233#endif 234#endif 235 /* Foxconn modified end pling 12/04/2009 */ 236 tmp.st_size = stat->size; 237 tmp.st_atime = stat->atime.tv_sec; 238 tmp.st_mtime = stat->mtime.tv_sec; 239 tmp.st_ctime = stat->ctime.tv_sec; 240#ifdef STAT_HAVE_NSEC 241 tmp.st_atime_nsec = stat->atime.tv_nsec; 242 tmp.st_mtime_nsec = stat->mtime.tv_nsec; 243 tmp.st_ctime_nsec = stat->ctime.tv_nsec; 244#endif 245 tmp.st_blocks = stat->blocks; 246 tmp.st_blksize = stat->blksize; 247 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; 248} 249 250SYSCALL_DEFINE2(newstat, const char __user *, filename, 251 struct stat __user *, statbuf) 252{ 253 struct kstat stat; 254 int error = vfs_stat(filename, &stat); 255 256 if (error) 257 return error; 258 return cp_new_stat(&stat, statbuf); 259} 260 261SYSCALL_DEFINE2(newlstat, const char __user *, filename, 262 struct stat __user *, statbuf) 263{ 264 struct kstat stat; 265 int error; 266 267 error = vfs_lstat(filename, &stat); 268 if (error) 269 return error; 270 271 return cp_new_stat(&stat, statbuf); 272} 273 274#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) 275SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, 276 struct stat __user *, statbuf, int, flag) 277{ 278 struct kstat stat; 279 int error; 280 281 error = vfs_fstatat(dfd, filename, &stat, flag); 282 if (error) 283 return error; 284 return cp_new_stat(&stat, statbuf); 285} 286#endif 287 288SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) 289{ 290 struct kstat stat; 291 int error = vfs_fstat(fd, &stat); 292 293 if (!error) 294 error = cp_new_stat(&stat, statbuf); 295 296 return error; 297} 298 299SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, 300 char __user *, buf, int, bufsiz) 301{ 302 struct path path; 303 int error; 304 305 if (bufsiz <= 0) 306 return -EINVAL; 307 308 error = user_path_at(dfd, pathname, 0, &path); 309 if (!error) { 310 struct inode *inode = path.dentry->d_inode; 311 312 error = -EINVAL; 313 if (inode->i_op->readlink) { 314 error = security_inode_readlink(path.dentry); 315 if (!error) { 316 touch_atime(path.mnt, path.dentry); 317 error = inode->i_op->readlink(path.dentry, 318 buf, bufsiz); 319 } 320 } 321 path_put(&path); 322 } 323 return error; 324} 325 326SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, 327 int, bufsiz) 328{ 329 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz); 330} 331 332 333/* ---------- LFS-64 ----------- */ 334#ifdef __ARCH_WANT_STAT64 335 336static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) 337{ 338 struct stat64 tmp; 339 340 memset(&tmp, 0, sizeof(struct stat64)); 341#ifdef CONFIG_MIPS 342 /* mips has weird padding, so we don't get 64 bits there */ 343 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) 344 return -EOVERFLOW; 345 tmp.st_dev = new_encode_dev(stat->dev); 346 tmp.st_rdev = new_encode_dev(stat->rdev); 347#else 348 tmp.st_dev = huge_encode_dev(stat->dev); 349 tmp.st_rdev = huge_encode_dev(stat->rdev); 350#endif 351 tmp.st_ino = stat->ino; 352 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) 353 return -EOVERFLOW; 354#ifdef STAT64_HAS_BROKEN_ST_INO 355 tmp.__st_ino = stat->ino; 356#endif 357 tmp.st_mode = stat->mode; 358 tmp.st_nlink = stat->nlink; 359 tmp.st_uid = stat->uid; 360 tmp.st_gid = stat->gid; 361 tmp.st_atime = stat->atime.tv_sec; 362 tmp.st_atime_nsec = stat->atime.tv_nsec; 363 tmp.st_mtime = stat->mtime.tv_sec; 364 tmp.st_mtime_nsec = stat->mtime.tv_nsec; 365 tmp.st_ctime = stat->ctime.tv_sec; 366 tmp.st_ctime_nsec = stat->ctime.tv_nsec; 367 tmp.st_size = stat->size; 368 tmp.st_blocks = stat->blocks; 369 tmp.st_blksize = stat->blksize; 370 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; 371} 372 373SYSCALL_DEFINE2(stat64, const char __user *, filename, 374 struct stat64 __user *, statbuf) 375{ 376 struct kstat stat; 377 int error = vfs_stat(filename, &stat); 378 379 if (!error) 380 error = cp_new_stat64(&stat, statbuf); 381 382 return error; 383} 384 385SYSCALL_DEFINE2(lstat64, const char __user *, filename, 386 struct stat64 __user *, statbuf) 387{ 388 struct kstat stat; 389 int error = vfs_lstat(filename, &stat); 390 391 if (!error) 392 error = cp_new_stat64(&stat, statbuf); 393 394 return error; 395} 396 397SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) 398{ 399 struct kstat stat; 400 int error = vfs_fstat(fd, &stat); 401 402 if (!error) 403 error = cp_new_stat64(&stat, statbuf); 404 405 return error; 406} 407 408SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, 409 struct stat64 __user *, statbuf, int, flag) 410{ 411 struct kstat stat; 412 int error; 413 414 error = vfs_fstatat(dfd, filename, &stat, flag); 415 if (error) 416 return error; 417 return cp_new_stat64(&stat, statbuf); 418} 419#endif /* __ARCH_WANT_STAT64 */ 420 421/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ 422void __inode_add_bytes(struct inode *inode, loff_t bytes) 423{ 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} 432 433void inode_add_bytes(struct inode *inode, loff_t bytes) 434{ 435 spin_lock(&inode->i_lock); 436 __inode_add_bytes(inode, bytes); 437 spin_unlock(&inode->i_lock); 438} 439 440EXPORT_SYMBOL(inode_add_bytes); 441 442void inode_sub_bytes(struct inode *inode, loff_t bytes) 443{ 444 spin_lock(&inode->i_lock); 445 inode->i_blocks -= bytes >> 9; 446 bytes &= 511; 447 if (inode->i_bytes < bytes) { 448 inode->i_blocks--; 449 inode->i_bytes += 512; 450 } 451 inode->i_bytes -= bytes; 452 spin_unlock(&inode->i_lock); 453} 454 455EXPORT_SYMBOL(inode_sub_bytes); 456 457loff_t inode_get_bytes(struct inode *inode) 458{ 459 loff_t ret; 460 461 spin_lock(&inode->i_lock); 462 ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; 463 spin_unlock(&inode->i_lock); 464 return ret; 465} 466 467EXPORT_SYMBOL(inode_get_bytes); 468 469void inode_set_bytes(struct inode *inode, loff_t bytes) 470{ 471 /* Caller is here responsible for sufficient locking 472 * (ie. inode->i_lock) */ 473 inode->i_blocks = bytes >> 9; 474 inode->i_bytes = bytes & 511; 475} 476 477EXPORT_SYMBOL(inode_set_bytes); 478