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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/fs/stat.c4 *5 * Copyright (C) 1991, 1992 Linus Torvalds6 */7 8#include <linux/blkdev.h>9#include <linux/export.h>10#include <linux/mm.h>11#include <linux/errno.h>12#include <linux/file.h>13#include <linux/highuid.h>14#include <linux/fs.h>15#include <linux/namei.h>16#include <linux/security.h>17#include <linux/cred.h>18#include <linux/syscalls.h>19#include <linux/pagemap.h>20#include <linux/compat.h>21#include <linux/iversion.h>22 23#include <linux/uaccess.h>24#include <asm/unistd.h>25 26#include "internal.h"27#include "mount.h"28 29/**30 * generic_fillattr - Fill in the basic attributes from the inode struct31 * @idmap: idmap of the mount the inode was found from32 * @request_mask: statx request_mask33 * @inode: Inode to use as the source34 * @stat: Where to fill in the attributes35 *36 * Fill in the basic attributes in the kstat structure from data that's to be37 * found on the VFS inode structure. This is the default if no getattr inode38 * operation is supplied.39 *40 * If the inode has been found through an idmapped mount the idmap of41 * the vfsmount must be passed through @idmap. This function will then42 * take care to map the inode according to @idmap before filling in the43 * uid and gid filds. On non-idmapped mounts or if permission checking is to be44 * performed on the raw inode simply pass @nop_mnt_idmap.45 */46void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask,47 struct inode *inode, struct kstat *stat)48{49 vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);50 vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);51 52 stat->dev = inode->i_sb->s_dev;53 stat->ino = inode->i_ino;54 stat->mode = inode->i_mode;55 stat->nlink = inode->i_nlink;56 stat->uid = vfsuid_into_kuid(vfsuid);57 stat->gid = vfsgid_into_kgid(vfsgid);58 stat->rdev = inode->i_rdev;59 stat->size = i_size_read(inode);60 stat->atime = inode_get_atime(inode);61 stat->mtime = inode_get_mtime(inode);62 stat->ctime = inode_get_ctime(inode);63 stat->blksize = i_blocksize(inode);64 stat->blocks = inode->i_blocks;65 66 if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {67 stat->result_mask |= STATX_CHANGE_COOKIE;68 stat->change_cookie = inode_query_iversion(inode);69 }70 71}72EXPORT_SYMBOL(generic_fillattr);73 74/**75 * generic_fill_statx_attr - Fill in the statx attributes from the inode flags76 * @inode: Inode to use as the source77 * @stat: Where to fill in the attribute flags78 *79 * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the80 * inode that are published on i_flags and enforced by the VFS.81 */82void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)83{84 if (inode->i_flags & S_IMMUTABLE)85 stat->attributes |= STATX_ATTR_IMMUTABLE;86 if (inode->i_flags & S_APPEND)87 stat->attributes |= STATX_ATTR_APPEND;88 stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;89}90EXPORT_SYMBOL(generic_fill_statx_attr);91 92/**93 * generic_fill_statx_atomic_writes - Fill in atomic writes statx attributes94 * @stat: Where to fill in the attribute flags95 * @unit_min: Minimum supported atomic write length in bytes96 * @unit_max: Maximum supported atomic write length in bytes97 *98 * Fill in the STATX{_ATTR}_WRITE_ATOMIC flags in the kstat structure from99 * atomic write unit_min and unit_max values.100 */101void generic_fill_statx_atomic_writes(struct kstat *stat,102 unsigned int unit_min,103 unsigned int unit_max)104{105 /* Confirm that the request type is known */106 stat->result_mask |= STATX_WRITE_ATOMIC;107 108 /* Confirm that the file attribute type is known */109 stat->attributes_mask |= STATX_ATTR_WRITE_ATOMIC;110 111 if (unit_min) {112 stat->atomic_write_unit_min = unit_min;113 stat->atomic_write_unit_max = unit_max;114 /* Initially only allow 1x segment */115 stat->atomic_write_segments_max = 1;116 117 /* Confirm atomic writes are actually supported */118 stat->attributes |= STATX_ATTR_WRITE_ATOMIC;119 }120}121EXPORT_SYMBOL_GPL(generic_fill_statx_atomic_writes);122 123/**124 * vfs_getattr_nosec - getattr without security checks125 * @path: file to get attributes from126 * @stat: structure to return attributes in127 * @request_mask: STATX_xxx flags indicating what the caller wants128 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)129 *130 * Get attributes without calling security_inode_getattr.131 *132 * Currently the only caller other than vfs_getattr is internal to the133 * filehandle lookup code, which uses only the inode number and returns no134 * attributes to any user. Any other code probably wants vfs_getattr.135 */136int vfs_getattr_nosec(const struct path *path, struct kstat *stat,137 u32 request_mask, unsigned int query_flags)138{139 struct mnt_idmap *idmap;140 struct inode *inode = d_backing_inode(path->dentry);141 142 memset(stat, 0, sizeof(*stat));143 stat->result_mask |= STATX_BASIC_STATS;144 query_flags &= AT_STATX_SYNC_TYPE;145 146 /* allow the fs to override these if it really wants to */147 /* SB_NOATIME means filesystem supplies dummy atime value */148 if (inode->i_sb->s_flags & SB_NOATIME)149 stat->result_mask &= ~STATX_ATIME;150 151 /*152 * Note: If you add another clause to set an attribute flag, please153 * update attributes_mask below.154 */155 if (IS_AUTOMOUNT(inode))156 stat->attributes |= STATX_ATTR_AUTOMOUNT;157 158 if (IS_DAX(inode))159 stat->attributes |= STATX_ATTR_DAX;160 161 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |162 STATX_ATTR_DAX);163 164 idmap = mnt_idmap(path->mnt);165 if (inode->i_op->getattr)166 return inode->i_op->getattr(idmap, path, stat,167 request_mask,168 query_flags | AT_GETATTR_NOSEC);169 170 generic_fillattr(idmap, request_mask, inode, stat);171 return 0;172}173EXPORT_SYMBOL(vfs_getattr_nosec);174 175/*176 * vfs_getattr - Get the enhanced basic attributes of a file177 * @path: The file of interest178 * @stat: Where to return the statistics179 * @request_mask: STATX_xxx flags indicating what the caller wants180 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)181 *182 * Ask the filesystem for a file's attributes. The caller must indicate in183 * request_mask and query_flags to indicate what they want.184 *185 * If the file is remote, the filesystem can be forced to update the attributes186 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can187 * suppress the update by passing AT_STATX_DONT_SYNC.188 *189 * Bits must have been set in request_mask to indicate which attributes the190 * caller wants retrieving. Any such attribute not requested may be returned191 * anyway, but the value may be approximate, and, if remote, may not have been192 * synchronised with the server.193 *194 * 0 will be returned on success, and a -ve error code if unsuccessful.195 */196int vfs_getattr(const struct path *path, struct kstat *stat,197 u32 request_mask, unsigned int query_flags)198{199 int retval;200 201 if (WARN_ON_ONCE(query_flags & AT_GETATTR_NOSEC))202 return -EPERM;203 204 retval = security_inode_getattr(path);205 if (retval)206 return retval;207 return vfs_getattr_nosec(path, stat, request_mask, query_flags);208}209EXPORT_SYMBOL(vfs_getattr);210 211/**212 * vfs_fstat - Get the basic attributes by file descriptor213 * @fd: The file descriptor referring to the file of interest214 * @stat: The result structure to fill in.215 *216 * This function is a wrapper around vfs_getattr(). The main difference is217 * that it uses a file descriptor to determine the file location.218 *219 * 0 will be returned on success, and a -ve error code if unsuccessful.220 */221int vfs_fstat(int fd, struct kstat *stat)222{223 struct fd f;224 int error;225 226 f = fdget_raw(fd);227 if (!fd_file(f))228 return -EBADF;229 error = vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);230 fdput(f);231 return error;232}233 234int getname_statx_lookup_flags(int flags)235{236 int lookup_flags = 0;237 238 if (!(flags & AT_SYMLINK_NOFOLLOW))239 lookup_flags |= LOOKUP_FOLLOW;240 if (!(flags & AT_NO_AUTOMOUNT))241 lookup_flags |= LOOKUP_AUTOMOUNT;242 if (flags & AT_EMPTY_PATH)243 lookup_flags |= LOOKUP_EMPTY;244 245 return lookup_flags;246}247 248static HWJS_SUSPENDS int vfs_statx_path(struct path *path, int flags, struct kstat *stat,249 u32 request_mask)250{251 int error = vfs_getattr(path, stat, request_mask, flags);252 253 if (request_mask & STATX_MNT_ID_UNIQUE) {254 stat->mnt_id = real_mount(path->mnt)->mnt_id_unique;255 stat->result_mask |= STATX_MNT_ID_UNIQUE;256 } else {257 stat->mnt_id = real_mount(path->mnt)->mnt_id;258 stat->result_mask |= STATX_MNT_ID;259 }260 261 if (path_mounted(path))262 stat->attributes |= STATX_ATTR_MOUNT_ROOT;263 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;264 265 /*266 * If this is a block device inode, override the filesystem267 * attributes with the block device specific parameters that need to be268 * obtained from the bdev backing inode.269 */270 if (S_ISBLK(stat->mode))271 bdev_statx(path, stat, request_mask);272 273 return error;274}275 276static HWJS_SUSPENDS int vfs_statx_fd(int fd, int flags, struct kstat *stat,277 u32 request_mask)278{279 CLASS(fd_raw, f)(fd);280 if (!fd_file(f))281 return -EBADF;282 return vfs_statx_path(&fd_file(f)->f_path, flags, stat, request_mask);283}284 285/**286 * vfs_statx - Get basic and extra attributes by filename287 * @dfd: A file descriptor representing the base dir for a relative filename288 * @filename: The name of the file of interest289 * @flags: Flags to control the query290 * @stat: The result structure to fill in.291 * @request_mask: STATX_xxx flags indicating what the caller wants292 *293 * This function is a wrapper around vfs_getattr(). The main difference is294 * that it uses a filename and base directory to determine the file location.295 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink296 * at the given name from being referenced.297 *298 * 0 will be returned on success, and a -ve error code if unsuccessful.299 */300static HWJS_SUSPENDS int vfs_statx(int dfd, struct filename *filename, int flags,301 struct kstat *stat, u32 request_mask)302{303 struct path path;304 unsigned int lookup_flags = getname_statx_lookup_flags(flags);305 int error;306 307 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |308 AT_STATX_SYNC_TYPE))309 return -EINVAL;310 311retry:312 error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);313 if (error)314 return error;315 error = vfs_statx_path(&path, flags, stat, request_mask);316 path_put(&path);317 if (retry_estale(error, lookup_flags)) {318 lookup_flags |= LOOKUP_REVAL;319 goto retry;320 }321 return error;322}323 324int vfs_fstatat(int dfd, const char __user *filename,325 struct kstat *stat, int flags)326{327 int ret;328 int statx_flags = flags | AT_NO_AUTOMOUNT;329 struct filename *name;330 331 /*332 * Work around glibc turning fstat() into fstatat(AT_EMPTY_PATH)333 *334 * If AT_EMPTY_PATH is set, we expect the common case to be that335 * empty path, and avoid doing all the extra pathname work.336 */337 if (flags == AT_EMPTY_PATH && vfs_empty_path(dfd, filename))338 return vfs_fstat(dfd, stat);339 340 name = getname_flags(filename, getname_statx_lookup_flags(statx_flags));341 ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);342 putname(name);343 344 return ret;345}346 347#ifdef __ARCH_WANT_OLD_STAT348 349/*350 * For backward compatibility? Maybe this should be moved351 * into arch/i386 instead?352 */353static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)354{355 static int warncount = 5;356 struct __old_kernel_stat tmp;357 358 if (warncount > 0) {359 warncount--;360 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",361 current->comm);362 } else if (warncount < 0) {363 /* it's laughable, but... */364 warncount = 0;365 }366 367 memset(&tmp, 0, sizeof(struct __old_kernel_stat));368 tmp.st_dev = old_encode_dev(stat->dev);369 tmp.st_ino = stat->ino;370 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)371 return -EOVERFLOW;372 tmp.st_mode = stat->mode;373 tmp.st_nlink = stat->nlink;374 if (tmp.st_nlink != stat->nlink)375 return -EOVERFLOW;376 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));377 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));378 tmp.st_rdev = old_encode_dev(stat->rdev);379#if BITS_PER_LONG == 32380 if (stat->size > MAX_NON_LFS)381 return -EOVERFLOW;382#endif383 tmp.st_size = stat->size;384 tmp.st_atime = stat->atime.tv_sec;385 tmp.st_mtime = stat->mtime.tv_sec;386 tmp.st_ctime = stat->ctime.tv_sec;387 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;388}389 390SYSCALL_DEFINE2(stat, const char __user *, filename,391 struct __old_kernel_stat __user *, statbuf)392{393 struct kstat stat;394 int error;395 396 error = vfs_stat(filename, &stat);397 if (error)398 return error;399 400 return cp_old_stat(&stat, statbuf);401}402 403SYSCALL_DEFINE2(lstat, const char __user *, filename,404 struct __old_kernel_stat __user *, statbuf)405{406 struct kstat stat;407 int error;408 409 error = vfs_lstat(filename, &stat);410 if (error)411 return error;412 413 return cp_old_stat(&stat, statbuf);414}415 416SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)417{418 struct kstat stat;419 int error = vfs_fstat(fd, &stat);420 421 if (!error)422 error = cp_old_stat(&stat, statbuf);423 424 return error;425}426 427#endif /* __ARCH_WANT_OLD_STAT */428 429#ifdef __ARCH_WANT_NEW_STAT430 431#ifndef INIT_STRUCT_STAT_PADDING432# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))433#endif434 435static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)436{437 struct stat tmp;438 439 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))440 return -EOVERFLOW;441 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))442 return -EOVERFLOW;443#if BITS_PER_LONG == 32444 if (stat->size > MAX_NON_LFS)445 return -EOVERFLOW;446#endif447 448 INIT_STRUCT_STAT_PADDING(tmp);449 tmp.st_dev = new_encode_dev(stat->dev);450 tmp.st_ino = stat->ino;451 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)452 return -EOVERFLOW;453 tmp.st_mode = stat->mode;454 tmp.st_nlink = stat->nlink;455 if (tmp.st_nlink != stat->nlink)456 return -EOVERFLOW;457 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));458 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));459 tmp.st_rdev = new_encode_dev(stat->rdev);460 tmp.st_size = stat->size;461 tmp.st_atime = stat->atime.tv_sec;462 tmp.st_mtime = stat->mtime.tv_sec;463 tmp.st_ctime = stat->ctime.tv_sec;464#ifdef STAT_HAVE_NSEC465 tmp.st_atime_nsec = stat->atime.tv_nsec;466 tmp.st_mtime_nsec = stat->mtime.tv_nsec;467 tmp.st_ctime_nsec = stat->ctime.tv_nsec;468#endif469 tmp.st_blocks = stat->blocks;470 tmp.st_blksize = stat->blksize;471 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;472}473 474SYSCALL_DEFINE2(newstat, const char __user *, filename,475 struct stat __user *, statbuf)476{477 struct kstat stat;478 int error = vfs_stat(filename, &stat);479 480 if (error)481 return error;482 return cp_new_stat(&stat, statbuf);483}484 485SYSCALL_DEFINE2(newlstat, const char __user *, filename,486 struct stat __user *, statbuf)487{488 struct kstat stat;489 int error;490 491 error = vfs_lstat(filename, &stat);492 if (error)493 return error;494 495 return cp_new_stat(&stat, statbuf);496}497 498#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)499SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,500 struct stat __user *, statbuf, int, flag)501{502 struct kstat stat;503 int error;504 505 error = vfs_fstatat(dfd, filename, &stat, flag);506 if (error)507 return error;508 return cp_new_stat(&stat, statbuf);509}510#endif511 512SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)513{514 struct kstat stat;515 int error = vfs_fstat(fd, &stat);516 517 if (!error)518 error = cp_new_stat(&stat, statbuf);519 520 return error;521}522#endif523 524static int do_readlinkat(int dfd, const char __user *pathname,525 char __user *buf, int bufsiz)526{527 struct path path;528 struct filename *name;529 int error;530 unsigned int lookup_flags = LOOKUP_EMPTY;531 532 if (bufsiz <= 0)533 return -EINVAL;534 535retry:536 name = getname_flags(pathname, lookup_flags);537 error = filename_lookup(dfd, name, lookup_flags, &path, NULL);538 if (unlikely(error)) {539 putname(name);540 return error;541 }542 543 /*544 * AFS mountpoints allow readlink(2) but are not symlinks545 */546 if (d_is_symlink(path.dentry) ||547 d_backing_inode(path.dentry)->i_op->readlink) {548 error = security_inode_readlink(path.dentry);549 if (!error) {550 touch_atime(&path);551 error = vfs_readlink(path.dentry, buf, bufsiz);552 }553 } else {554 error = (name->name[0] == '\0') ? -ENOENT : -EINVAL;555 }556 path_put(&path);557 putname(name);558 if (retry_estale(error, lookup_flags)) {559 lookup_flags |= LOOKUP_REVAL;560 goto retry;561 }562 return error;563}564 565SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,566 char __user *, buf, int, bufsiz)567{568 return do_readlinkat(dfd, pathname, buf, bufsiz);569}570 571SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,572 int, bufsiz)573{574 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);575}576 577 578/* ---------- LFS-64 ----------- */579#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)580 581#ifndef INIT_STRUCT_STAT64_PADDING582# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))583#endif584 585static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)586{587 struct stat64 tmp;588 589 INIT_STRUCT_STAT64_PADDING(tmp);590#ifdef CONFIG_MIPS591 /* mips has weird padding, so we don't get 64 bits there */592 tmp.st_dev = new_encode_dev(stat->dev);593 tmp.st_rdev = new_encode_dev(stat->rdev);594#else595 tmp.st_dev = huge_encode_dev(stat->dev);596 tmp.st_rdev = huge_encode_dev(stat->rdev);597#endif598 tmp.st_ino = stat->ino;599 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)600 return -EOVERFLOW;601#ifdef STAT64_HAS_BROKEN_ST_INO602 tmp.__st_ino = stat->ino;603#endif604 tmp.st_mode = stat->mode;605 tmp.st_nlink = stat->nlink;606 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);607 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);608 tmp.st_atime = stat->atime.tv_sec;609 tmp.st_atime_nsec = stat->atime.tv_nsec;610 tmp.st_mtime = stat->mtime.tv_sec;611 tmp.st_mtime_nsec = stat->mtime.tv_nsec;612 tmp.st_ctime = stat->ctime.tv_sec;613 tmp.st_ctime_nsec = stat->ctime.tv_nsec;614 tmp.st_size = stat->size;615 tmp.st_blocks = stat->blocks;616 tmp.st_blksize = stat->blksize;617 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;618}619 620SYSCALL_DEFINE2(stat64, const char __user *, filename,621 struct stat64 __user *, statbuf)622{623 struct kstat stat;624 int error = vfs_stat(filename, &stat);625 626 if (!error)627 error = cp_new_stat64(&stat, statbuf);628 629 return error;630}631 632SYSCALL_DEFINE2(lstat64, const char __user *, filename,633 struct stat64 __user *, statbuf)634{635 struct kstat stat;636 int error = vfs_lstat(filename, &stat);637 638 if (!error)639 error = cp_new_stat64(&stat, statbuf);640 641 return error;642}643 644SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)645{646 struct kstat stat;647 int error = vfs_fstat(fd, &stat);648 649 if (!error)650 error = cp_new_stat64(&stat, statbuf);651 652 return error;653}654 655SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,656 struct stat64 __user *, statbuf, int, flag)657{658 struct kstat stat;659 int error;660 661 error = vfs_fstatat(dfd, filename, &stat, flag);662 if (error)663 return error;664 return cp_new_stat64(&stat, statbuf);665}666#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */667 668static noinline_for_stack int669cp_statx(const struct kstat *stat, struct statx __user *buffer)670{671 struct statx tmp;672 673 memset(&tmp, 0, sizeof(tmp));674 675 /* STATX_CHANGE_COOKIE is kernel-only for now */676 tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;677 tmp.stx_blksize = stat->blksize;678 /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */679 tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;680 tmp.stx_nlink = stat->nlink;681 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);682 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);683 tmp.stx_mode = stat->mode;684 tmp.stx_ino = stat->ino;685 tmp.stx_size = stat->size;686 tmp.stx_blocks = stat->blocks;687 tmp.stx_attributes_mask = stat->attributes_mask;688 tmp.stx_atime.tv_sec = stat->atime.tv_sec;689 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;690 tmp.stx_btime.tv_sec = stat->btime.tv_sec;691 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;692 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;693 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;694 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;695 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;696 tmp.stx_rdev_major = MAJOR(stat->rdev);697 tmp.stx_rdev_minor = MINOR(stat->rdev);698 tmp.stx_dev_major = MAJOR(stat->dev);699 tmp.stx_dev_minor = MINOR(stat->dev);700 tmp.stx_mnt_id = stat->mnt_id;701 tmp.stx_dio_mem_align = stat->dio_mem_align;702 tmp.stx_dio_offset_align = stat->dio_offset_align;703 tmp.stx_subvol = stat->subvol;704 tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;705 tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;706 tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;707 708 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;709}710 711int do_statx(int dfd, struct filename *filename, unsigned int flags,712 unsigned int mask, struct statx __user *buffer)713{714 struct kstat stat;715 int error;716 717 if (mask & STATX__RESERVED)718 return -EINVAL;719 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)720 return -EINVAL;721 722 /*723 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests724 * from userland.725 */726 mask &= ~STATX_CHANGE_COOKIE;727 728 error = vfs_statx(dfd, filename, flags, &stat, mask);729 if (error)730 return error;731 732 return cp_statx(&stat, buffer);733}734 735int do_statx_fd(int fd, unsigned int flags, unsigned int mask,736 struct statx __user *buffer)737{738 struct kstat stat;739 int error;740 741 if (mask & STATX__RESERVED)742 return -EINVAL;743 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)744 return -EINVAL;745 746 /*747 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests748 * from userland.749 */750 mask &= ~STATX_CHANGE_COOKIE;751 752 error = vfs_statx_fd(fd, flags, &stat, mask);753 if (error)754 return error;755 756 return cp_statx(&stat, buffer);757}758 759/**760 * sys_statx - System call to get enhanced stats761 * @dfd: Base directory to pathwalk from *or* fd to stat.762 * @filename: File to stat or either NULL or "" with AT_EMPTY_PATH763 * @flags: AT_* flags to control pathwalk.764 * @mask: Parts of statx struct actually required.765 * @buffer: Result buffer.766 *767 * Note that fstat() can be emulated by setting dfd to the fd of interest,768 * supplying "" (or preferably NULL) as the filename and setting AT_EMPTY_PATH769 * in the flags.770 */771SYSCALL_DEFINE5(statx,772 int, dfd, const char __user *, filename, unsigned, flags,773 unsigned int, mask,774 struct statx __user *, buffer)775{776 int ret;777 unsigned lflags;778 struct filename *name;779 780 /*781 * Short-circuit handling of NULL and "" paths.782 *783 * For a NULL path we require and accept only the AT_EMPTY_PATH flag784 * (possibly |'d with AT_STATX flags).785 *786 * However, glibc on 32-bit architectures implements fstatat as statx787 * with the "" pathname and AT_NO_AUTOMOUNT | AT_EMPTY_PATH flags.788 * Supporting this results in the uglification below.789 */790 lflags = flags & ~(AT_NO_AUTOMOUNT | AT_STATX_SYNC_TYPE);791 if (lflags == AT_EMPTY_PATH && vfs_empty_path(dfd, filename))792 return do_statx_fd(dfd, flags & ~AT_NO_AUTOMOUNT, mask, buffer);793 794 name = getname_flags(filename, getname_statx_lookup_flags(flags));795 ret = do_statx(dfd, name, flags, mask, buffer);796 putname(name);797 798 return ret;799}800 801#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)802static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)803{804 struct compat_stat tmp;805 806 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))807 return -EOVERFLOW;808 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))809 return -EOVERFLOW;810 811 memset(&tmp, 0, sizeof(tmp));812 tmp.st_dev = new_encode_dev(stat->dev);813 tmp.st_ino = stat->ino;814 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)815 return -EOVERFLOW;816 tmp.st_mode = stat->mode;817 tmp.st_nlink = stat->nlink;818 if (tmp.st_nlink != stat->nlink)819 return -EOVERFLOW;820 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));821 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));822 tmp.st_rdev = new_encode_dev(stat->rdev);823 if ((u64) stat->size > MAX_NON_LFS)824 return -EOVERFLOW;825 tmp.st_size = stat->size;826 tmp.st_atime = stat->atime.tv_sec;827 tmp.st_atime_nsec = stat->atime.tv_nsec;828 tmp.st_mtime = stat->mtime.tv_sec;829 tmp.st_mtime_nsec = stat->mtime.tv_nsec;830 tmp.st_ctime = stat->ctime.tv_sec;831 tmp.st_ctime_nsec = stat->ctime.tv_nsec;832 tmp.st_blocks = stat->blocks;833 tmp.st_blksize = stat->blksize;834 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;835}836 837COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,838 struct compat_stat __user *, statbuf)839{840 struct kstat stat;841 int error;842 843 error = vfs_stat(filename, &stat);844 if (error)845 return error;846 return cp_compat_stat(&stat, statbuf);847}848 849COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,850 struct compat_stat __user *, statbuf)851{852 struct kstat stat;853 int error;854 855 error = vfs_lstat(filename, &stat);856 if (error)857 return error;858 return cp_compat_stat(&stat, statbuf);859}860 861#ifndef __ARCH_WANT_STAT64862COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,863 const char __user *, filename,864 struct compat_stat __user *, statbuf, int, flag)865{866 struct kstat stat;867 int error;868 869 error = vfs_fstatat(dfd, filename, &stat, flag);870 if (error)871 return error;872 return cp_compat_stat(&stat, statbuf);873}874#endif875 876COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,877 struct compat_stat __user *, statbuf)878{879 struct kstat stat;880 int error = vfs_fstat(fd, &stat);881 882 if (!error)883 error = cp_compat_stat(&stat, statbuf);884 return error;885}886#endif887 888/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */889void __inode_add_bytes(struct inode *inode, loff_t bytes)890{891 inode->i_blocks += bytes >> 9;892 bytes &= 511;893 inode->i_bytes += bytes;894 if (inode->i_bytes >= 512) {895 inode->i_blocks++;896 inode->i_bytes -= 512;897 }898}899EXPORT_SYMBOL(__inode_add_bytes);900 901void inode_add_bytes(struct inode *inode, loff_t bytes)902{903 spin_lock(&inode->i_lock);904 __inode_add_bytes(inode, bytes);905 spin_unlock(&inode->i_lock);906}907 908EXPORT_SYMBOL(inode_add_bytes);909 910void __inode_sub_bytes(struct inode *inode, loff_t bytes)911{912 inode->i_blocks -= bytes >> 9;913 bytes &= 511;914 if (inode->i_bytes < bytes) {915 inode->i_blocks--;916 inode->i_bytes += 512;917 }918 inode->i_bytes -= bytes;919}920 921EXPORT_SYMBOL(__inode_sub_bytes);922 923void inode_sub_bytes(struct inode *inode, loff_t bytes)924{925 spin_lock(&inode->i_lock);926 __inode_sub_bytes(inode, bytes);927 spin_unlock(&inode->i_lock);928}929 930EXPORT_SYMBOL(inode_sub_bytes);931 932loff_t inode_get_bytes(struct inode *inode)933{934 loff_t ret;935 936 spin_lock(&inode->i_lock);937 ret = __inode_get_bytes(inode);938 spin_unlock(&inode->i_lock);939 return ret;940}941 942EXPORT_SYMBOL(inode_get_bytes);943 944void inode_set_bytes(struct inode *inode, loff_t bytes)945{946 /* Caller is here responsible for sufficient locking947 * (ie. inode->i_lock) */948 inode->i_blocks = bytes >> 9;949 inode->i_bytes = bytes & 511;950}951 952EXPORT_SYMBOL(inode_set_bytes);953