| /* |
| * linux/fs/stat.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| */ |
| |
| #include <linux/export.h> |
| #include <linux/mm.h> |
| #include <linux/errno.h> |
| #include <linux/file.h> |
| #include <linux/highuid.h> |
| #include <linux/fs.h> |
| #include <linux/namei.h> |
| #include <linux/security.h> |
| #include <linux/syscalls.h> |
| #include <linux/pagemap.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/unistd.h> |
| |
| void generic_fillattr(struct inode *inode, struct kstat *stat) |
| { |
| stat->dev = inode->i_sb->s_dev; |
| stat->ino = inode->i_ino; |
| stat->mode = inode->i_mode; |
| stat->nlink = inode->i_nlink; |
| stat->uid = inode->i_uid; |
| stat->gid = inode->i_gid; |
| stat->rdev = inode->i_rdev; |
| stat->size = i_size_read(inode); |
| stat->atime = inode->i_atime; |
| stat->mtime = inode->i_mtime; |
| stat->ctime = inode->i_ctime; |
| stat->blksize = (1 << inode->i_blkbits); |
| stat->blocks = inode->i_blocks; |
| } |
| |
| EXPORT_SYMBOL(generic_fillattr); |
| |
| /** |
| * vfs_getattr_nosec - getattr without security checks |
| * @path: file to get attributes from |
| * @stat: structure to return attributes in |
| * |
| * Get attributes without calling security_inode_getattr. |
| * |
| * Currently the only caller other than vfs_getattr is internal to the |
| * filehandle lookup code, which uses only the inode number and returns |
| * no attributes to any user. Any other code probably wants |
| * vfs_getattr. |
| */ |
| int vfs_getattr_nosec(struct path *path, struct kstat *stat) |
| { |
| struct inode *inode = d_backing_inode(path->dentry); |
| |
| if (inode->i_op->getattr) |
| return inode->i_op->getattr(path->mnt, path->dentry, stat); |
| |
| generic_fillattr(inode, stat); |
| return 0; |
| } |
| |
| EXPORT_SYMBOL(vfs_getattr_nosec); |
| |
| int vfs_getattr(struct path *path, struct kstat *stat) |
| { |
| int retval; |
| |
| retval = security_inode_getattr(path); |
| if (retval) |
| return retval; |
| return vfs_getattr_nosec(path, stat); |
| } |
| |
| EXPORT_SYMBOL(vfs_getattr); |
| |
| int vfs_fstat(unsigned int fd, struct kstat *stat) |
| { |
| struct fd f = fdget_raw(fd); |
| int error = -EBADF; |
| |
| if (f.file) { |
| error = vfs_getattr(&f.file->f_path, stat); |
| fdput(f); |
| } |
| return error; |
| } |
| EXPORT_SYMBOL(vfs_fstat); |
| |
| int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, |
| int flag) |
| { |
| struct path path; |
| int error = -EINVAL; |
| unsigned int lookup_flags = 0; |
| |
| if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | |
| AT_EMPTY_PATH)) != 0) |
| goto out; |
| |
| if (!(flag & AT_SYMLINK_NOFOLLOW)) |
| lookup_flags |= LOOKUP_FOLLOW; |
| if (flag & AT_EMPTY_PATH) |
| lookup_flags |= LOOKUP_EMPTY; |
| retry: |
| error = user_path_at(dfd, filename, lookup_flags, &path); |
| if (error) |
| goto out; |
| |
| error = vfs_getattr(&path, stat); |
| path_put(&path); |
| if (retry_estale(error, lookup_flags)) { |
| lookup_flags |= LOOKUP_REVAL; |
| goto retry; |
| } |
| out: |
| return error; |
| } |
| EXPORT_SYMBOL(vfs_fstatat); |
| |
| int vfs_stat(const char __user *name, struct kstat *stat) |
| { |
| return vfs_fstatat(AT_FDCWD, name, stat, 0); |
| } |
| EXPORT_SYMBOL(vfs_stat); |
| |
| int vfs_lstat(const char __user *name, struct kstat *stat) |
| { |
| return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); |
| } |
| EXPORT_SYMBOL(vfs_lstat); |
| |
| |
| #ifdef __ARCH_WANT_OLD_STAT |
| |
| /* |
| * For backward compatibility? Maybe this should be moved |
| * into arch/i386 instead? |
| */ |
| static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) |
| { |
| static int warncount = 5; |
| struct __old_kernel_stat tmp; |
| |
| if (warncount > 0) { |
| warncount--; |
| printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", |
| current->comm); |
| } else if (warncount < 0) { |
| /* it's laughable, but... */ |
| warncount = 0; |
| } |
| |
| memset(&tmp, 0, sizeof(struct __old_kernel_stat)); |
| tmp.st_dev = old_encode_dev(stat->dev); |
| tmp.st_ino = stat->ino; |
| if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
| return -EOVERFLOW; |
| tmp.st_mode = stat->mode; |
| tmp.st_nlink = stat->nlink; |
| if (tmp.st_nlink != stat->nlink) |
| return -EOVERFLOW; |
| SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
| SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); |
| tmp.st_rdev = old_encode_dev(stat->rdev); |
| #if BITS_PER_LONG == 32 |
| if (stat->size > MAX_NON_LFS) |
| return -EOVERFLOW; |
| #endif |
| tmp.st_size = stat->size; |
| tmp.st_atime = stat->atime.tv_sec; |
| tmp.st_mtime = stat->mtime.tv_sec; |
| tmp.st_ctime = stat->ctime.tv_sec; |
| return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
| } |
| |
| SYSCALL_DEFINE2(stat, const char __user *, filename, |
| struct __old_kernel_stat __user *, statbuf) |
| { |
| struct kstat stat; |
| int error; |
| |
| error = vfs_stat(filename, &stat); |
| if (error) |
| return error; |
| |
| return cp_old_stat(&stat, statbuf); |
| } |
| |
| SYSCALL_DEFINE2(lstat, const char __user *, filename, |
| struct __old_kernel_stat __user *, statbuf) |
| { |
| struct kstat stat; |
| int error; |
| |
| error = vfs_lstat(filename, &stat); |
| if (error) |
| return error; |
| |
| return cp_old_stat(&stat, statbuf); |
| } |
| |
| SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_fstat(fd, &stat); |
| |
| if (!error) |
| error = cp_old_stat(&stat, statbuf); |
| |
| return error; |
| } |
| |
| #endif /* __ARCH_WANT_OLD_STAT */ |
| |
| #if BITS_PER_LONG == 32 |
| # define choose_32_64(a,b) a |
| #else |
| # define choose_32_64(a,b) b |
| #endif |
| |
| #define valid_dev(x) choose_32_64(old_valid_dev(x),true) |
| #define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x) |
| |
| #ifndef INIT_STRUCT_STAT_PADDING |
| # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st)) |
| #endif |
| |
| static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) |
| { |
| struct stat tmp; |
| |
| if (!valid_dev(stat->dev) || !valid_dev(stat->rdev)) |
| return -EOVERFLOW; |
| #if BITS_PER_LONG == 32 |
| if (stat->size > MAX_NON_LFS) |
| return -EOVERFLOW; |
| #endif |
| |
| INIT_STRUCT_STAT_PADDING(tmp); |
| tmp.st_dev = encode_dev(stat->dev); |
| tmp.st_ino = stat->ino; |
| if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
| return -EOVERFLOW; |
| tmp.st_mode = stat->mode; |
| tmp.st_nlink = stat->nlink; |
| if (tmp.st_nlink != stat->nlink) |
| return -EOVERFLOW; |
| SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
| SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); |
| tmp.st_rdev = encode_dev(stat->rdev); |
| tmp.st_size = stat->size; |
| tmp.st_atime = stat->atime.tv_sec; |
| tmp.st_mtime = stat->mtime.tv_sec; |
| tmp.st_ctime = stat->ctime.tv_sec; |
| #ifdef STAT_HAVE_NSEC |
| tmp.st_atime_nsec = stat->atime.tv_nsec; |
| tmp.st_mtime_nsec = stat->mtime.tv_nsec; |
| tmp.st_ctime_nsec = stat->ctime.tv_nsec; |
| #endif |
| tmp.st_blocks = stat->blocks; |
| tmp.st_blksize = stat->blksize; |
| return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
| } |
| |
| SYSCALL_DEFINE2(newstat, const char __user *, filename, |
| struct stat __user *, statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_stat(filename, &stat); |
| |
| if (error) |
| return error; |
| return cp_new_stat(&stat, statbuf); |
| } |
| |
| SYSCALL_DEFINE2(newlstat, const char __user *, filename, |
| struct stat __user *, statbuf) |
| { |
| struct kstat stat; |
| int error; |
| |
| error = vfs_lstat(filename, &stat); |
| if (error) |
| return error; |
| |
| return cp_new_stat(&stat, statbuf); |
| } |
| |
| #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) |
| SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, |
| struct stat __user *, statbuf, int, flag) |
| { |
| struct kstat stat; |
| int error; |
| |
| error = vfs_fstatat(dfd, filename, &stat, flag); |
| if (error) |
| return error; |
| return cp_new_stat(&stat, statbuf); |
| } |
| #endif |
| |
| SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_fstat(fd, &stat); |
| |
| if (!error) |
| error = cp_new_stat(&stat, statbuf); |
| |
| return error; |
| } |
| |
| SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, |
| char __user *, buf, int, bufsiz) |
| { |
| struct path path; |
| int error; |
| int empty = 0; |
| unsigned int lookup_flags = LOOKUP_EMPTY; |
| |
| if (bufsiz <= 0) |
| return -EINVAL; |
| |
| retry: |
| error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty); |
| if (!error) { |
| struct inode *inode = d_backing_inode(path.dentry); |
| |
| error = empty ? -ENOENT : -EINVAL; |
| /* |
| * AFS mountpoints allow readlink(2) but are not symlinks |
| */ |
| if (d_is_symlink(path.dentry) || inode->i_op->readlink) { |
| error = security_inode_readlink(path.dentry); |
| if (!error) { |
| touch_atime(&path); |
| error = vfs_readlink(path.dentry, buf, bufsiz); |
| } |
| } |
| path_put(&path); |
| if (retry_estale(error, lookup_flags)) { |
| lookup_flags |= LOOKUP_REVAL; |
| goto retry; |
| } |
| } |
| return error; |
| } |
| |
| SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, |
| int, bufsiz) |
| { |
| return sys_readlinkat(AT_FDCWD, path, buf, bufsiz); |
| } |
| |
| |
| /* ---------- LFS-64 ----------- */ |
| #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64) |
| |
| #ifndef INIT_STRUCT_STAT64_PADDING |
| # define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st)) |
| #endif |
| |
| static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) |
| { |
| struct stat64 tmp; |
| |
| INIT_STRUCT_STAT64_PADDING(tmp); |
| #ifdef CONFIG_MIPS |
| /* mips has weird padding, so we don't get 64 bits there */ |
| tmp.st_dev = new_encode_dev(stat->dev); |
| tmp.st_rdev = new_encode_dev(stat->rdev); |
| #else |
| tmp.st_dev = huge_encode_dev(stat->dev); |
| tmp.st_rdev = huge_encode_dev(stat->rdev); |
| #endif |
| tmp.st_ino = stat->ino; |
| if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
| return -EOVERFLOW; |
| #ifdef STAT64_HAS_BROKEN_ST_INO |
| tmp.__st_ino = stat->ino; |
| #endif |
| tmp.st_mode = stat->mode; |
| tmp.st_nlink = stat->nlink; |
| tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid); |
| tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid); |
| tmp.st_atime = stat->atime.tv_sec; |
| tmp.st_atime_nsec = stat->atime.tv_nsec; |
| tmp.st_mtime = stat->mtime.tv_sec; |
| tmp.st_mtime_nsec = stat->mtime.tv_nsec; |
| tmp.st_ctime = stat->ctime.tv_sec; |
| tmp.st_ctime_nsec = stat->ctime.tv_nsec; |
| tmp.st_size = stat->size; |
| tmp.st_blocks = stat->blocks; |
| tmp.st_blksize = stat->blksize; |
| return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
| } |
| |
| SYSCALL_DEFINE2(stat64, const char __user *, filename, |
| struct stat64 __user *, statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_stat(filename, &stat); |
| |
| if (!error) |
| error = cp_new_stat64(&stat, statbuf); |
| |
| return error; |
| } |
| |
| SYSCALL_DEFINE2(lstat64, const char __user *, filename, |
| struct stat64 __user *, statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_lstat(filename, &stat); |
| |
| if (!error) |
| error = cp_new_stat64(&stat, statbuf); |
| |
| return error; |
| } |
| |
| SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_fstat(fd, &stat); |
| |
| if (!error) |
| error = cp_new_stat64(&stat, statbuf); |
| |
| return error; |
| } |
| |
| SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, |
| struct stat64 __user *, statbuf, int, flag) |
| { |
| struct kstat stat; |
| int error; |
| |
| error = vfs_fstatat(dfd, filename, &stat, flag); |
| if (error) |
| return error; |
| return cp_new_stat64(&stat, statbuf); |
| } |
| #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */ |
| |
| /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ |
| void __inode_add_bytes(struct inode *inode, loff_t bytes) |
| { |
| inode->i_blocks += bytes >> 9; |
| bytes &= 511; |
| inode->i_bytes += bytes; |
| if (inode->i_bytes >= 512) { |
| inode->i_blocks++; |
| inode->i_bytes -= 512; |
| } |
| } |
| |
| void inode_add_bytes(struct inode *inode, loff_t bytes) |
| { |
| spin_lock(&inode->i_lock); |
| __inode_add_bytes(inode, bytes); |
| spin_unlock(&inode->i_lock); |
| } |
| |
| EXPORT_SYMBOL(inode_add_bytes); |
| |
| void __inode_sub_bytes(struct inode *inode, loff_t bytes) |
| { |
| inode->i_blocks -= bytes >> 9; |
| bytes &= 511; |
| if (inode->i_bytes < bytes) { |
| inode->i_blocks--; |
| inode->i_bytes += 512; |
| } |
| inode->i_bytes -= bytes; |
| } |
| |
| EXPORT_SYMBOL(__inode_sub_bytes); |
| |
| void inode_sub_bytes(struct inode *inode, loff_t bytes) |
| { |
| spin_lock(&inode->i_lock); |
| __inode_sub_bytes(inode, bytes); |
| spin_unlock(&inode->i_lock); |
| } |
| |
| EXPORT_SYMBOL(inode_sub_bytes); |
| |
| loff_t inode_get_bytes(struct inode *inode) |
| { |
| loff_t ret; |
| |
| spin_lock(&inode->i_lock); |
| ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; |
| spin_unlock(&inode->i_lock); |
| return ret; |
| } |
| |
| EXPORT_SYMBOL(inode_get_bytes); |
| |
| void inode_set_bytes(struct inode *inode, loff_t bytes) |
| { |
| /* Caller is here responsible for sufficient locking |
| * (ie. inode->i_lock) */ |
| inode->i_blocks = bytes >> 9; |
| inode->i_bytes = bytes & 511; |
| } |
| |
| EXPORT_SYMBOL(inode_set_bytes); |