Viewing file:  stat.c (9.34 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* linux/fs/stat.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/config.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <linux/highuid.h>
#include <asm/uaccess.h>
/*
* Revalidate the inode. This is required for proper NFS attribute caching.
*/
static __inline__ int
do_revalidate(struct dentry *dentry)
{
struct inode * inode = dentry->d_inode;
if (inode->i_op && inode->i_op->revalidate)
return inode->i_op->revalidate(dentry);
return 0;
}
#if !defined(__alpha__) && !defined(__sparc__) && !defined(__ia64__) && !defined(CONFIG_ARCH_S390) && !defined(__hppa__) && !defined(__x86_64__)
/*
* For backward compatibility? Maybe this should be moved
* into arch/i386 instead?
*/
static int cp_old_stat(struct inode * inode, struct __old_kernel_stat * 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;
}
tmp.st_dev = kdev_t_to_nr(inode->i_dev);
tmp.st_ino = inode->i_ino;
tmp.st_mode = inode->i_mode;
tmp.st_nlink = inode->i_nlink;
SET_OLDSTAT_UID(tmp, inode->i_uid);
SET_OLDSTAT_GID(tmp, inode->i_gid);
tmp.st_rdev = kdev_t_to_nr(inode->i_rdev);
#if BITS_PER_LONG == 32
if (inode->i_size > MAX_NON_LFS)
return -EOVERFLOW;
#endif
tmp.st_size = inode->i_size;
tmp.st_atime = inode->i_atime;
tmp.st_mtime = inode->i_mtime;
tmp.st_ctime = inode->i_ctime;
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}
#endif
static int cp_new_stat(struct inode * inode, struct stat * statbuf)
{
struct stat tmp;
unsigned int blocks, indirect;
memset(&tmp, 0, sizeof(tmp));
tmp.st_dev = kdev_t_to_nr(inode->i_dev);
tmp.st_ino = inode->i_ino;
tmp.st_mode = inode->i_mode;
tmp.st_nlink = inode->i_nlink;
SET_STAT_UID(tmp, inode->i_uid);
SET_STAT_GID(tmp, inode->i_gid);
tmp.st_rdev = kdev_t_to_nr(inode->i_rdev);
#if BITS_PER_LONG == 32
if (inode->i_size > MAX_NON_LFS)
return -EOVERFLOW;
#endif
tmp.st_size = inode->i_size;
tmp.st_atime = inode->i_atime;
tmp.st_mtime = inode->i_mtime;
tmp.st_ctime = inode->i_ctime;
/*
* st_blocks and st_blksize are approximated with a simple algorithm if
* they aren't supported directly by the filesystem. The minix and msdos
* filesystems don't keep track of blocks, so they would either have to
* be counted explicitly (by delving into the file itself), or by using
* this simple algorithm to get a reasonable (although not 100% accurate)
* value.
*/
/*
* Use minix fs values for the number of direct and indirect blocks. The
* count is now exact for the minix fs except that it counts zero blocks.
* Everything is in units of BLOCK_SIZE until the assignment to
* tmp.st_blksize.
*/
#define D_B 7
#define I_B (BLOCK_SIZE / sizeof(unsigned short))
if (!inode->i_blksize) {
blocks = (tmp.st_size + BLOCK_SIZE - 1) / BLOCK_SIZE;
if (blocks > D_B) {
indirect = (blocks - D_B + I_B - 1) / I_B;
blocks += indirect;
if (indirect > 1) {
indirect = (indirect - 1 + I_B - 1) / I_B;
blocks += indirect;
if (indirect > 1)
blocks++;
}
}
tmp.st_blocks = (BLOCK_SIZE / 512) * blocks;
tmp.st_blksize = BLOCK_SIZE;
} else {
tmp.st_blocks = inode->i_blocks;
tmp.st_blksize = inode->i_blksize;
}
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}
#if !defined(__alpha__) && !defined(__sparc__) && !defined(__ia64__) && !defined(CONFIG_ARCH_S390) && !defined(__hppa__) && !defined(__x86_64__)
/*
* For backward compatibility? Maybe this should be moved
* into arch/i386 instead?
*/
asmlinkage long sys_stat(char * filename, struct __old_kernel_stat * statbuf)
{
struct nameidata nd;
int error;
error = user_path_walk(filename, &nd);
if (!error) {
error = do_revalidate(nd.dentry);
if (!error)
error = cp_old_stat(nd.dentry->d_inode, statbuf);
path_release(&nd);
}
return error;
}
#endif
asmlinkage long sys_newstat(char * filename, struct stat * statbuf)
{
struct nameidata nd;
int error;
error = user_path_walk(filename, &nd);
if (!error) {
error = do_revalidate(nd.dentry);
if (!error)
error = cp_new_stat(nd.dentry->d_inode, statbuf);
path_release(&nd);
}
return error;
}
#if !defined(__alpha__) && !defined(__sparc__) && !defined(__ia64__) && !defined(CONFIG_ARCH_S390) && !defined(__hppa__) && !defined(__x86_64__)
/*
* For backward compatibility? Maybe this should be moved
* into arch/i386 instead?
*/
asmlinkage long sys_lstat(char * filename, struct __old_kernel_stat * statbuf)
{
struct nameidata nd;
int error;
error = user_path_walk_link(filename, &nd);
if (!error) {
error = do_revalidate(nd.dentry);
if (!error)
error = cp_old_stat(nd.dentry->d_inode, statbuf);
path_release(&nd);
}
return error;
}
#endif
asmlinkage long sys_newlstat(char * filename, struct stat * statbuf)
{
struct nameidata nd;
int error;
error = user_path_walk_link(filename, &nd);
if (!error) {
error = do_revalidate(nd.dentry);
if (!error)
error = cp_new_stat(nd.dentry->d_inode, statbuf);
path_release(&nd);
}
return error;
}
#if !defined(__alpha__) && !defined(__sparc__) && !defined(__ia64__) && !defined(CONFIG_ARCH_S390) && !defined(__hppa__) && !defined(__x86_64__)
/*
* For backward compatibility? Maybe this should be moved
* into arch/i386 instead?
*/
asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat * statbuf)
{
struct file * f;
int err = -EBADF;
f = fget(fd);
if (f) {
struct dentry * dentry = f->f_dentry;
err = do_revalidate(dentry);
if (!err)
err = cp_old_stat(dentry->d_inode, statbuf);
fput(f);
}
return err;
}
#endif
asmlinkage long sys_newfstat(unsigned int fd, struct stat * statbuf)
{
struct file * f;
int err = -EBADF;
f = fget(fd);
if (f) {
struct dentry * dentry = f->f_dentry;
err = do_revalidate(dentry);
if (!err)
err = cp_new_stat(dentry->d_inode, statbuf);
fput(f);
}
return err;
}
asmlinkage long sys_readlink(const char * path, char * buf, int bufsiz)
{
struct nameidata nd;
int error;
if (bufsiz <= 0)
return -EINVAL;
error = user_path_walk_link(path, &nd);
if (!error) {
struct inode * inode = nd.dentry->d_inode;
error = -EINVAL;
if (inode->i_op && inode->i_op->readlink &&
!(error = do_revalidate(nd.dentry))) {
UPDATE_ATIME(inode);
error = inode->i_op->readlink(nd.dentry, buf, bufsiz);
}
path_release(&nd);
}
return error;
}
/* ---------- LFS-64 ----------- */
#if !defined(__alpha__) && !defined(__ia64__) && !defined(__mips64) && !defined(__x86_64__) && !defined(CONFIG_ARCH_S390X)
static long cp_new_stat64(struct inode * inode, struct stat64 * statbuf)
{
struct stat64 tmp;
unsigned int blocks, indirect;
memset(&tmp, 0, sizeof(tmp));
tmp.st_dev = kdev_t_to_nr(inode->i_dev);
tmp.st_ino = inode->i_ino;
#ifdef STAT64_HAS_BROKEN_ST_INO
tmp.__st_ino = inode->i_ino;
#endif
tmp.st_mode = inode->i_mode;
tmp.st_nlink = inode->i_nlink;
tmp.st_uid = inode->i_uid;
tmp.st_gid = inode->i_gid;
tmp.st_rdev = kdev_t_to_nr(inode->i_rdev);
tmp.st_atime = inode->i_atime;
tmp.st_mtime = inode->i_mtime;
tmp.st_ctime = inode->i_ctime;
tmp.st_size = inode->i_size;
/*
* st_blocks and st_blksize are approximated with a simple algorithm if
* they aren't supported directly by the filesystem. The minix and msdos
* filesystems don't keep track of blocks, so they would either have to
* be counted explicitly (by delving into the file itself), or by using
* this simple algorithm to get a reasonable (although not 100% accurate)
* value.
*/
/*
* Use minix fs values for the number of direct and indirect blocks. The
* count is now exact for the minix fs except that it counts zero blocks.
* Everything is in units of BLOCK_SIZE until the assignment to
* tmp.st_blksize.
*/
#define D_B 7
#define I_B (BLOCK_SIZE / sizeof(unsigned short))
if (!inode->i_blksize) {
blocks = (tmp.st_size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
if (blocks > D_B) {
indirect = (blocks - D_B + I_B - 1) / I_B;
blocks += indirect;
if (indirect > 1) {
indirect = (indirect - 1 + I_B - 1) / I_B;
blocks += indirect;
if (indirect > 1)
blocks++;
}
}
tmp.st_blocks = (BLOCK_SIZE / 512) * blocks;
tmp.st_blksize = BLOCK_SIZE;
} else {
tmp.st_blocks = inode->i_blocks;
tmp.st_blksize = inode->i_blksize;
}
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}
asmlinkage long sys_stat64(char * filename, struct stat64 * statbuf, long flags)
{
struct nameidata nd;
int error;
error = user_path_walk(filename, &nd);
if (!error) {
error = do_revalidate(nd.dentry);
if (!error)
error = cp_new_stat64(nd.dentry->d_inode, statbuf);
path_release(&nd);
}
return error;
}
asmlinkage long sys_lstat64(char * filename, struct stat64 * statbuf, long flags)
{
struct nameidata nd;
int error;
error = user_path_walk_link(filename, &nd);
if (!error) {
error = do_revalidate(nd.dentry);
if (!error)
error = cp_new_stat64(nd.dentry->d_inode, statbuf);
path_release(&nd);
}
return error;
}
asmlinkage long sys_fstat64(unsigned long fd, struct stat64 * statbuf, long flags)
{
struct file * f;
int err = -EBADF;
f = fget(fd);
if (f) {
struct dentry * dentry = f->f_dentry;
err = do_revalidate(dentry);
if (!err)
err = cp_new_stat64(dentry->d_inode, statbuf);
fput(f);
}
return err;
}
#endif /* LFS-64 */
|