mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 09:50:04 +00:00
![David Howells](/assets/img/avatar_default.png)
These patches make the kernel pass 64-bit inode numbers internally when communicating to userspace, even on a 32-bit system. They are required because some filesystems have intrinsic 64-bit inode numbers: NFS3+ and XFS for example. The 64-bit inode numbers are then propagated to userspace automatically where the arch supports it. Problems have been seen with userspace (eg: ld.so) using the 64-bit inode number returned by stat64() or getdents64() to differentiate files, and failing because the 64-bit inode number space was compressed to 32-bits, and so overlaps occur. This patch: Make filldir_t take a 64-bit inode number and struct kstat carry a 64-bit inode number so that 64-bit inode numbers can be passed back to userspace. The stat functions then returns the full 64-bit inode number where available and where possible. If it is not possible to represent the inode number supplied by the filesystem in the field provided by userspace, then error EOVERFLOW will be issued. Similarly, the getdents/readdir functions now pass the full 64-bit inode number to userspace where possible, returning EOVERFLOW instead when a directory entry is encountered that can't be properly represented. Note that this means that some inodes will not be stat'able on a 32-bit system with old libraries where they were before - but it does mean that there will be no ambiguity over what a 32-bit inode number refers to. Note similarly that directory scans may be cut short with an error on a 32-bit system with old libraries where the scan would work before for the same reasons. It is judged unlikely that this situation will occur because modern glibc uses 64-bit capable versions of stat and getdents class functions exclusively, and that older systems are unlikely to encounter unrepresentable inode numbers anyway. [akpm: alpha build fix] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
478 lines
11 KiB
C
478 lines
11 KiB
C
/*
|
|
* linux/fs/stat.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/file.h>
|
|
#include <linux/smp_lock.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->atime = inode->i_atime;
|
|
stat->mtime = inode->i_mtime;
|
|
stat->ctime = inode->i_ctime;
|
|
stat->size = i_size_read(inode);
|
|
stat->blocks = inode->i_blocks;
|
|
stat->blksize = (1 << inode->i_blkbits);
|
|
}
|
|
|
|
EXPORT_SYMBOL(generic_fillattr);
|
|
|
|
int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
int retval;
|
|
|
|
retval = security_inode_getattr(mnt, dentry);
|
|
if (retval)
|
|
return retval;
|
|
|
|
if (inode->i_op->getattr)
|
|
return inode->i_op->getattr(mnt, dentry, stat);
|
|
|
|
generic_fillattr(inode, stat);
|
|
if (!stat->blksize) {
|
|
struct super_block *s = inode->i_sb;
|
|
unsigned blocks;
|
|
blocks = (stat->size+s->s_blocksize-1) >> s->s_blocksize_bits;
|
|
stat->blocks = (s->s_blocksize / 512) * blocks;
|
|
stat->blksize = s->s_blocksize;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(vfs_getattr);
|
|
|
|
int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat)
|
|
{
|
|
struct nameidata nd;
|
|
int error;
|
|
|
|
error = __user_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd);
|
|
if (!error) {
|
|
error = vfs_getattr(nd.mnt, nd.dentry, stat);
|
|
path_release(&nd);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
int vfs_stat(char __user *name, struct kstat *stat)
|
|
{
|
|
return vfs_stat_fd(AT_FDCWD, name, stat);
|
|
}
|
|
|
|
EXPORT_SYMBOL(vfs_stat);
|
|
|
|
int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat)
|
|
{
|
|
struct nameidata nd;
|
|
int error;
|
|
|
|
error = __user_walk_fd(dfd, name, 0, &nd);
|
|
if (!error) {
|
|
error = vfs_getattr(nd.mnt, nd.dentry, stat);
|
|
path_release(&nd);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
int vfs_lstat(char __user *name, struct kstat *stat)
|
|
{
|
|
return vfs_lstat_fd(AT_FDCWD, name, stat);
|
|
}
|
|
|
|
EXPORT_SYMBOL(vfs_lstat);
|
|
|
|
int vfs_fstat(unsigned int fd, struct kstat *stat)
|
|
{
|
|
struct file *f = fget(fd);
|
|
int error = -EBADF;
|
|
|
|
if (f) {
|
|
error = vfs_getattr(f->f_vfsmnt, f->f_dentry, stat);
|
|
fput(f);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
EXPORT_SYMBOL(vfs_fstat);
|
|
|
|
#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, stat->uid);
|
|
SET_GID(tmp.st_gid, 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;
|
|
}
|
|
|
|
asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
|
|
|
|
if (!error)
|
|
error = cp_old_stat(&stat, statbuf);
|
|
|
|
return error;
|
|
}
|
|
asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
|
|
|
|
if (!error)
|
|
error = cp_old_stat(&stat, statbuf);
|
|
|
|
return error;
|
|
}
|
|
asmlinkage long sys_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 */
|
|
|
|
static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
|
|
{
|
|
struct stat tmp;
|
|
|
|
#if BITS_PER_LONG == 32
|
|
if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
|
|
return -EOVERFLOW;
|
|
#else
|
|
if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
|
|
return -EOVERFLOW;
|
|
#endif
|
|
|
|
memset(&tmp, 0, sizeof(tmp));
|
|
#if BITS_PER_LONG == 32
|
|
tmp.st_dev = old_encode_dev(stat->dev);
|
|
#else
|
|
tmp.st_dev = new_encode_dev(stat->dev);
|
|
#endif
|
|
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, stat->uid);
|
|
SET_GID(tmp.st_gid, stat->gid);
|
|
#if BITS_PER_LONG == 32
|
|
tmp.st_rdev = old_encode_dev(stat->rdev);
|
|
#else
|
|
tmp.st_rdev = new_encode_dev(stat->rdev);
|
|
#endif
|
|
#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;
|
|
#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;
|
|
}
|
|
|
|
asmlinkage long sys_newstat(char __user *filename, struct stat __user *statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
|
|
|
|
if (!error)
|
|
error = cp_new_stat(&stat, statbuf);
|
|
|
|
return error;
|
|
}
|
|
|
|
asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
|
|
|
|
if (!error)
|
|
error = cp_new_stat(&stat, statbuf);
|
|
|
|
return error;
|
|
}
|
|
|
|
#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
|
|
asmlinkage long sys_newfstatat(int dfd, char __user *filename,
|
|
struct stat __user *statbuf, int flag)
|
|
{
|
|
struct kstat stat;
|
|
int error = -EINVAL;
|
|
|
|
if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
|
|
goto out;
|
|
|
|
if (flag & AT_SYMLINK_NOFOLLOW)
|
|
error = vfs_lstat_fd(dfd, filename, &stat);
|
|
else
|
|
error = vfs_stat_fd(dfd, filename, &stat);
|
|
|
|
if (!error)
|
|
error = cp_new_stat(&stat, statbuf);
|
|
|
|
out:
|
|
return error;
|
|
}
|
|
#endif
|
|
|
|
asmlinkage long sys_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;
|
|
}
|
|
|
|
asmlinkage long sys_readlinkat(int dfd, const char __user *path,
|
|
char __user *buf, int bufsiz)
|
|
{
|
|
struct nameidata nd;
|
|
int error;
|
|
|
|
if (bufsiz <= 0)
|
|
return -EINVAL;
|
|
|
|
error = __user_walk_fd(dfd, path, 0, &nd);
|
|
if (!error) {
|
|
struct inode * inode = nd.dentry->d_inode;
|
|
|
|
error = -EINVAL;
|
|
if (inode->i_op && inode->i_op->readlink) {
|
|
error = security_inode_readlink(nd.dentry);
|
|
if (!error) {
|
|
touch_atime(nd.mnt, nd.dentry);
|
|
error = inode->i_op->readlink(nd.dentry, buf, bufsiz);
|
|
}
|
|
}
|
|
path_release(&nd);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
asmlinkage long sys_readlink(const char __user *path, char __user *buf,
|
|
int bufsiz)
|
|
{
|
|
return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
|
|
}
|
|
|
|
|
|
/* ---------- LFS-64 ----------- */
|
|
#ifdef __ARCH_WANT_STAT64
|
|
|
|
static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
|
|
{
|
|
struct stat64 tmp;
|
|
|
|
memset(&tmp, 0, sizeof(struct stat64));
|
|
#ifdef CONFIG_MIPS
|
|
/* mips has weird padding, so we don't get 64 bits there */
|
|
if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
|
|
return -EOVERFLOW;
|
|
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 = stat->uid;
|
|
tmp.st_gid = 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;
|
|
}
|
|
|
|
asmlinkage long sys_stat64(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;
|
|
}
|
|
asmlinkage long sys_lstat64(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;
|
|
}
|
|
asmlinkage long sys_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;
|
|
}
|
|
|
|
asmlinkage long sys_fstatat64(int dfd, char __user *filename,
|
|
struct stat64 __user *statbuf, int flag)
|
|
{
|
|
struct kstat stat;
|
|
int error = -EINVAL;
|
|
|
|
if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
|
|
goto out;
|
|
|
|
if (flag & AT_SYMLINK_NOFOLLOW)
|
|
error = vfs_lstat_fd(dfd, filename, &stat);
|
|
else
|
|
error = vfs_stat_fd(dfd, filename, &stat);
|
|
|
|
if (!error)
|
|
error = cp_new_stat64(&stat, statbuf);
|
|
|
|
out:
|
|
return error;
|
|
}
|
|
#endif /* __ARCH_WANT_STAT64 */
|
|
|
|
void inode_add_bytes(struct inode *inode, loff_t bytes)
|
|
{
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_blocks += bytes >> 9;
|
|
bytes &= 511;
|
|
inode->i_bytes += bytes;
|
|
if (inode->i_bytes >= 512) {
|
|
inode->i_blocks++;
|
|
inode->i_bytes -= 512;
|
|
}
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
|
|
EXPORT_SYMBOL(inode_add_bytes);
|
|
|
|
void inode_sub_bytes(struct inode *inode, loff_t bytes)
|
|
{
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_blocks -= bytes >> 9;
|
|
bytes &= 511;
|
|
if (inode->i_bytes < bytes) {
|
|
inode->i_blocks--;
|
|
inode->i_bytes += 512;
|
|
}
|
|
inode->i_bytes -= 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);
|