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/*

 *  linux/fs/stat.c

 *

 *  Copyright (C) 1991, 1992  Linus Torvalds

 */

#include <linux/errno.h>

#include <linux/string.h>

#include <linux/stat.h>

#include <linux/fs.h>

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <asm/segment.h>

#ifndef __alpha__

/*

 * For backward compatibility?  Maybe this should be moved

 * into arch/i386 instead?

 */

static void cp_old_stat(struct inode * inode, struct old_stat * statbuf)

{

        struct old_stat tmp;

        static int nagcount = 0;

        if (++nagcount < 5)

                printk("VFS: Warning: %s using old stat() call. "

                        "Recompile your binary.\n",

                        current->comm);

        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;

        tmp.st_uid = inode->i_uid;

        tmp.st_gid = inode->i_gid;

        tmp.st_rdev = kdev_t_to_nr(inode->i_rdev);

        tmp.st_size = inode->i_size;

        if (inode->i_pipe)

                tmp.st_size = PIPE_SIZE(*inode);

        tmp.st_atime = inode->i_atime;

        tmp.st_mtime = inode->i_mtime;

        tmp.st_ctime = inode->i_ctime;

        memcpy_tofs(statbuf,&tmp,sizeof(tmp));

}

#endif

static void cp_new_stat(struct inode * inode, struct new_stat * statbuf)

{

        struct new_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;

        tmp.st_uid = inode->i_uid;

        tmp.st_gid = inode->i_gid;

        tmp.st_rdev = kdev_t_to_nr(inode->i_rdev);

        tmp.st_size = inode->i_size;

        if (inode->i_pipe)

                tmp.st_size = PIPE_SIZE(*inode);

        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 BLOCK_SIZE'd units 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;

        }

        memcpy_tofs(statbuf,&tmp,sizeof(tmp));

}

#ifndef __alpha__

/*

 * For backward compatibility?  Maybe this should be moved

 * into arch/i386 instead?

 */

asmlinkage int sys_stat(char * filename, struct old_stat * statbuf)

{

        struct inode * inode;

        int error;

        error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf));

        if (error)

                return error;

        error = namei(filename,&inode);

        if (error)

                return error;

        cp_old_stat(inode,statbuf);

        iput(inode);

        return 0;

}

#endif

asmlinkage int sys_newstat(char * filename, struct new_stat * statbuf)

{

        struct inode * inode;

        int error;

        error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf));

        if (error)

                return error;

        error = namei(filename,&inode);

        if (error)

                return error;

        cp_new_stat(inode,statbuf);

        iput(inode);

        return 0;

}

#ifndef __alpha__

/*

 * For backward compatibility?  Maybe this should be moved

 * into arch/i386 instead?

 */

asmlinkage int sys_lstat(char * filename, struct old_stat * statbuf)

{

        struct inode * inode;

        int error;

        error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf));

        if (error)

                return error;

        error = lnamei(filename,&inode);

        if (error)

                return error;

        cp_old_stat(inode,statbuf);

        iput(inode);

        return 0;

}

#endif

asmlinkage int sys_newlstat(char * filename, struct new_stat * statbuf)

{

        struct inode * inode;

        int error;

        error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf));

        if (error)

                return error;

        error = lnamei(filename,&inode);

        if (error)

                return error;

        cp_new_stat(inode,statbuf);

        iput(inode);

        return 0;

}

#ifndef __alpha__

/*

 * For backward compatibility?  Maybe this should be moved

 * into arch/i386 instead?

 */

asmlinkage int sys_fstat(unsigned int fd, struct old_stat * statbuf)

{

        struct file * f;

        struct inode * inode;

        int error;

        error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf));

        if (error)

                return error;

        if (fd >= NR_OPEN || !(f=current->files->fd[fd]) || !(inode=f->f_inode))

                return -EBADF;

        cp_old_stat(inode,statbuf);

        return 0;

}

#endif

asmlinkage int sys_newfstat(unsigned int fd, struct new_stat * statbuf)

{

        struct file * f;

        struct inode * inode;

        int error;

        error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf));

        if (error)

                return error;

        if (fd >= NR_OPEN || !(f=current->files->fd[fd]) || !(inode=f->f_inode))

                return -EBADF;

        cp_new_stat(inode,statbuf);

        return 0;

}

asmlinkage int sys_readlink(const char * path, char * buf, int bufsiz)

{

        struct inode * inode;

        int error;

        if (bufsiz <= 0)

                return -EINVAL;

        error = verify_area(VERIFY_WRITE,buf,bufsiz);

        if (error)

                return error;

        error = lnamei(path,&inode);

        if (error)

                return error;

        if (!inode->i_op || !inode->i_op->readlink) {

                iput(inode);

                return -EINVAL;

        }

        UPDATE_ATIME(inode);

        return inode->i_op->readlink(inode,buf,bufsiz);

}