URL https://opencores.org/ocsvn/or1k_old/or1k_old/trunk

Subversion Repositories or1k_old

[/] [or1k_old/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [open.c] - Blame information for rev 1782

Details | Compare with Previous | View Log


/*
 *  linux/fs/open.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */
 
/*
 * uClinux revisions for NO_MM
 * Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>,
 *                     The Silver Hammer Group, Ltd.
 */
 
#include <linux/vfs.h>
#include <linux/types.h>
#include <linux/utime.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/tty.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/file.h>
 
#include <asm/segment.h>
#include <asm/bitops.h>
 
asmlinkage int sys_statfs(const char * path, struct statfs * buf)
{
        struct inode * inode;
        int error;
 
        error = verify_area(VERIFY_WRITE, buf, sizeof(struct statfs));
        if (error)
                return error;
        error = namei(path,&inode);
        if (error)
                return error;
        if (!inode->i_sb->s_op->statfs) {
                iput(inode);
                return -ENOSYS;
        }
        inode->i_sb->s_op->statfs(inode->i_sb, buf, sizeof(struct statfs));
        iput(inode);
        return 0;
}
 
asmlinkage int sys_fstatfs(unsigned int fd, struct statfs * buf)
{
        struct inode * inode;
        struct file * file;
        int error;
 
        error = verify_area(VERIFY_WRITE, buf, sizeof(struct statfs));
        if (error)
                return error;
        if (fd >= NR_OPEN || !(file = current->files->fd[fd]))
                return -EBADF;
        if (!(inode = file->f_inode))
                return -ENOENT;
        if (!inode->i_sb)
                return -ENODEV;
        if (!inode->i_sb->s_op->statfs)
                return -ENOSYS;
        inode->i_sb->s_op->statfs(inode->i_sb, buf, sizeof(struct statfs));
        return 0;
}
 
int do_truncate(struct inode *inode, unsigned long length)
{
        int error;
        struct iattr newattrs;
 
        /* Not pretty: "inode->i_size" shouldn't really be "off_t". But it is. */
        if ((off_t) length < 0)
                return -EINVAL;
 
        down(&inode->i_sem);
        newattrs.ia_size = length;
        newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
        error = notify_change(inode, &newattrs);
        if (!error) {
                /* truncate virtual mappings of this file */
#ifndef NO_MM
                vmtruncate(inode, length);
#endif /* !NO_MM */
                if (inode->i_op && inode->i_op->truncate)
                        inode->i_op->truncate(inode);
        }
        up(&inode->i_sem);
        return error;
}
 
asmlinkage int sys_truncate(const char * path, unsigned long length)
{
        struct inode * inode;
        int error;
 
        error = namei(path,&inode);
        if (error)
                return error;
 
        error = -EACCES;
        if (S_ISDIR(inode->i_mode))
                goto out;
 
        error = permission(inode,MAY_WRITE);
        if (error)
                goto out;
 
        error = -EROFS;
        if (IS_RDONLY(inode))
                goto out;
 
        error = -EPERM;
        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                goto out;
 
        error = get_write_access(inode);
        if (error)
                goto out;
 
        error = locks_verify_area(FLOCK_VERIFY_WRITE, inode, NULL,
                                  length < inode->i_size ? length : inode->i_size,
                                  abs(inode->i_size - length));
        if (!error) {
                if (inode->i_sb && inode->i_sb->dq_op)
                        inode->i_sb->dq_op->initialize(inode, -1);
                error = do_truncate(inode, length);
        }
        put_write_access(inode);
out:
        iput(inode);
        return error;
}
 
asmlinkage int sys_ftruncate(unsigned int fd, unsigned long length)
{
        struct inode * inode;
        struct file * file;
        int error;
 
        if (fd >= NR_OPEN || !(file = current->files->fd[fd]))
                return -EBADF;
        if (!(inode = file->f_inode))
                return -ENOENT;
        if (S_ISDIR(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
                return -EACCES;
        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                return -EPERM;
        error = locks_verify_area(FLOCK_VERIFY_WRITE, inode, file,
                                  length < inode->i_size ? length : inode->i_size,
                                  abs(inode->i_size - length));
        if (!error)
                error = do_truncate(inode, length);
        return error;
}
 
#ifndef __alpha__
 
/*
 * sys_utime() can be implemented in user-level using sys_utimes().
 * Is this for backwards compatibility?  If so, why not move it
 * into the appropriate arch directory (for those architectures that
 * need it).
 */
 
/* If times==NULL, set access and modification to current time,
 * must be owner or have write permission.
 * Else, update from *times, must be owner or super user.
 */
asmlinkage int sys_utime(char * filename, struct utimbuf * times)
{
        int error;
        struct inode * inode;
        struct iattr newattrs;
 
        error = namei(filename,&inode);
        if (error)
                return error;
        if (IS_RDONLY(inode)) {
                iput(inode);
                return -EROFS;
        }
        /* Don't worry, the checks are done in inode_change_ok() */
        newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
        if (times) {
                error = verify_area(VERIFY_READ, times, sizeof(*times));
                if (error) {
                        iput(inode);
                        return error;
                }
                newattrs.ia_atime = get_user(&times->actime);
                newattrs.ia_mtime = get_user(&times->modtime);
                newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
        } else {
                if (current->fsuid != inode->i_uid &&
                    (error = permission(inode,MAY_WRITE)) != 0) {
                        iput(inode);
                        return error;
                }
        }
        error = notify_change(inode, &newattrs);
        iput(inode);
        return error;
}
 
#endif
 
/* If times==NULL, set access and modification to current time,
 * must be owner or have write permission.
 * Else, update from *times, must be owner or super user.
 */
asmlinkage int sys_utimes(char * filename, struct timeval * utimes)
{
        int error;
        struct inode * inode;
        struct iattr newattrs;
 
        error = namei(filename,&inode);
        if (error)
                return error;
        if (IS_RDONLY(inode)) {
                iput(inode);
                return -EROFS;
        }
        /* Don't worry, the checks are done in inode_change_ok() */
        newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
        if (utimes) {
                struct timeval times[2];
                error = verify_area(VERIFY_READ, utimes, sizeof(times));
                if (error) {
                        iput(inode);
                        return error;
                }
                memcpy_fromfs(&times, utimes, sizeof(times));
                newattrs.ia_atime = times[0].tv_sec;
                newattrs.ia_mtime = times[1].tv_sec;
                newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
        } else {
                if ((error = permission(inode,MAY_WRITE)) != 0) {
                        iput(inode);
                        return error;
                }
        }
        error = notify_change(inode, &newattrs);
        iput(inode);
        return error;
}
 
/*
 * access() needs to use the real uid/gid, not the effective uid/gid.
 * We do this by temporarily setting fsuid/fsgid to the wanted values
 */
asmlinkage int sys_access(const char * filename, int mode)
{
        struct inode * inode;
        int old_fsuid, old_fsgid;
        int res;
 
        if (mode != (mode & S_IRWXO))   /* where's F_OK, X_OK, W_OK, R_OK? */
                return -EINVAL;
        old_fsuid = current->fsuid;
        old_fsgid = current->fsgid;
        current->fsuid = current->uid;
        current->fsgid = current->gid;
        res = namei(filename,&inode);
        if (!res) {
                res = permission(inode, mode);
                iput(inode);
        }
        current->fsuid = old_fsuid;
        current->fsgid = old_fsgid;
        return res;
}
 
asmlinkage int sys_chdir(const char * filename)
{
        struct inode * inode;
        int error;
 
        error = namei(filename,&inode);
        if (error)
                return error;
        if (!S_ISDIR(inode->i_mode)) {
                iput(inode);
                return -ENOTDIR;
        }
        if ((error = permission(inode,MAY_EXEC)) != 0) {
                iput(inode);
                return error;
        }
        iput(current->fs->pwd);
        current->fs->pwd = inode;
        return (0);
}
 
asmlinkage int sys_fchdir(unsigned int fd)
{
        struct inode * inode;
        struct file * file;
        int error;
 
        if (fd >= NR_OPEN || !(file = current->files->fd[fd]))
                return -EBADF;
        if (!(inode = file->f_inode))
                return -ENOENT;
        if (!S_ISDIR(inode->i_mode))
                return -ENOTDIR;
        if ((error = permission(inode,MAY_EXEC)) != 0)
                return error;
        iput(current->fs->pwd);
        current->fs->pwd = inode;
        inode->i_count++;
        return (0);
}
 
asmlinkage int sys_chroot(const char * filename)
{
        struct inode * inode;
        int error;
 
        error = namei(filename,&inode);
        if (error)
                return error;
        if (!S_ISDIR(inode->i_mode)) {
                iput(inode);
                return -ENOTDIR;
        }
        if (!fsuser()) {
                iput(inode);
                return -EPERM;
        }
        iput(current->fs->root);
        current->fs->root = inode;
        return (0);
}
 
asmlinkage int sys_fchmod(unsigned int fd, mode_t mode)
{
        struct inode * inode;
        struct file * file;
        struct iattr newattrs;
 
        if (fd >= NR_OPEN || !(file = current->files->fd[fd]))
                return -EBADF;
        if (!(inode = file->f_inode))
                return -ENOENT;
        if (IS_RDONLY(inode))
                return -EROFS;
        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                return -EPERM;
        if (mode == (mode_t) -1)
                mode = inode->i_mode;
        newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
        newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
        inode->i_dirt = 1;
        return notify_change(inode, &newattrs);
}
 
asmlinkage int sys_chmod(const char * filename, mode_t mode)
{
        struct inode * inode;
        int error;
        struct iattr newattrs;
 
        error = namei(filename,&inode);
        if (error)
                return error;
        if (IS_RDONLY(inode)) {
                iput(inode);
                return -EROFS;
        }
        if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) {
                iput(inode);
                return -EPERM;
        }
        if (mode == (mode_t) -1)
                mode = inode->i_mode;
        newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
        newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
        inode->i_dirt = 1;
        error = notify_change(inode, &newattrs);
        iput(inode);
        return error;
}
 
asmlinkage int sys_fchown(unsigned int fd, uid_t user, gid_t group)
{
        struct inode * inode;
        struct file * file;
        struct iattr newattrs;
        int error;
 
        if (fd >= NR_OPEN || !(file = current->files->fd[fd]))
                return -EBADF;
        if (!(inode = file->f_inode))
                return -ENOENT;
        if (IS_RDONLY(inode))
                return -EROFS;
        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                return -EPERM;
        if (user == (uid_t) -1)
                user = inode->i_uid;
        if (group == (gid_t) -1)
                group = inode->i_gid;
        newattrs.ia_mode = inode->i_mode;
        newattrs.ia_uid = user;
        newattrs.ia_gid = group;
        newattrs.ia_valid =  ATTR_UID | ATTR_GID | ATTR_CTIME;
        /*
         * If the owner has been changed, remove the setuid bit
         */
        if (inode->i_mode & S_ISUID) {
                newattrs.ia_mode &= ~S_ISUID;
                newattrs.ia_valid |= ATTR_MODE;
        }
        /*
         * If the group has been changed, remove the setgid bit
         *
         * Don't remove the setgid bit if no group execute bit.
         * This is a file marked for mandatory locking.
         */
        if (((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))) {
                newattrs.ia_mode &= ~S_ISGID;
                newattrs.ia_valid |= ATTR_MODE;
        }
        inode->i_dirt = 1;
        if (inode->i_sb && inode->i_sb->dq_op) {
                inode->i_sb->dq_op->initialize(inode, -1);
                if (inode->i_sb->dq_op->transfer(inode, &newattrs, 0))
                        return -EDQUOT;
                error = notify_change(inode, &newattrs);
                if (error)
                        inode->i_sb->dq_op->transfer(inode, &newattrs, 1);
        } else
                error = notify_change(inode, &newattrs);
        return error;
}
 
asmlinkage int sys_chown(const char * filename, uid_t user, gid_t group)
{
        struct inode * inode;
        int error;
        struct iattr newattrs;
 
        error = lnamei(filename,&inode);
        if (error)
                return error;
        if (IS_RDONLY(inode)) {
                iput(inode);
                return -EROFS;
        }
        if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) {
                iput(inode);
                return -EPERM;
        }
        if (user == (uid_t) -1)
                user = inode->i_uid;
        if (group == (gid_t) -1)
                group = inode->i_gid;
        newattrs.ia_mode = inode->i_mode;
        newattrs.ia_uid = user;
        newattrs.ia_gid = group;
        newattrs.ia_valid =  ATTR_UID | ATTR_GID | ATTR_CTIME;
        /*
         * If the owner has been changed, remove the setuid bit
         */
        if (inode->i_mode & S_ISUID) {
                newattrs.ia_mode &= ~S_ISUID;
                newattrs.ia_valid |= ATTR_MODE;
        }
        /*
         * If the group has been changed, remove the setgid bit
         *
         * Don't remove the setgid bit if no group execute bit.
         * This is a file marked for mandatory locking.
         */
        if (((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))) {
                newattrs.ia_mode &= ~S_ISGID;
                newattrs.ia_valid |= ATTR_MODE;
        }
        inode->i_dirt = 1;
        if (inode->i_sb->dq_op) {
                inode->i_sb->dq_op->initialize(inode, -1);
                if (inode->i_sb->dq_op->transfer(inode, &newattrs, 0))
                        return -EDQUOT;
                error = notify_change(inode, &newattrs);
                if (error)
                        inode->i_sb->dq_op->transfer(inode, &newattrs, 1);
        } else
                error = notify_change(inode, &newattrs);
        iput(inode);
        return(error);
}
 
/*
 * Note that while the flag value (low two bits) for sys_open means:
 *      00 - read-only
 *      01 - write-only
 *      10 - read-write
 *      11 - special
 * it is changed into
 *      00 - no permissions needed
 *      01 - read-permission
 *      10 - write-permission
 *      11 - read-write
 * for the internal routines (ie open_namei()/follow_link() etc). 00 is
 * used by symlinks.
 */
static int do_open(const char * filename,int flags,int mode, int fd)
{
        struct inode * inode;
        struct file * f;
        int flag,error;
 
        f = get_empty_filp();
 
        if (!f)
                return -ENFILE;
        f->f_flags = flag = flags;
        f->f_mode = (flag+1) & O_ACCMODE;
        if (f->f_mode)
                flag++;
        if (flag & O_TRUNC)
                flag |= 2;
        error = open_namei(filename,flag,mode,&inode,NULL);
        if (error)
                goto cleanup_file;
        if (f->f_mode & FMODE_WRITE) {
                error = get_write_access(inode);
                if (error)
                        goto cleanup_inode;
        }
 
        f->f_inode = inode;
        f->f_pos = 0;
        f->f_reada = 0;
        f->f_op = NULL;
        if (inode->i_op)
                f->f_op = inode->i_op->default_file_ops;
        if (f->f_op && f->f_op->open) {
                error = f->f_op->open(inode,f);
                if (error)
                        goto cleanup_all;
        }
        f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
 
        current->files->fd[fd] = f;
        return 0;
 
cleanup_all:
        if (f->f_mode & FMODE_WRITE)
                put_write_access(inode);
cleanup_inode:
        iput(inode);
cleanup_file:
        f->f_count--;
        return error;
}
 
/*
 * Find a empty file descriptor entry, and mark it busy
 */
int get_unused_fd(void)
{
        int fd;
        struct files_struct * files = current->files;
 
        fd = find_first_zero_bit(&files->open_fds, NR_OPEN);
        if (fd < current->rlim[RLIMIT_NOFILE].rlim_cur) {
                FD_SET(fd, &files->open_fds);
                FD_CLR(fd, &files->close_on_exec);
                return fd;
        }
        return -EMFILE;
}
 
inline void put_unused_fd(int fd)
{
        FD_CLR(fd, &current->files->open_fds);
}
 
asmlinkage int sys_open(const char * filename,int flags,int mode)
{
        char * tmp;
        int fd, error;
 
        fd = get_unused_fd();
        if (fd < 0)
                return fd;
        error = getname(filename, &tmp);
        if (!error) {
                error = do_open(tmp,flags,mode, fd);
                putname(tmp);
 
                if (!error)
                        return fd;
        }
 
        put_unused_fd(fd);
        return error;
}
 
#ifndef __alpha__
 
/*
 * For backward compatibility?  Maybe this should be moved
 * into arch/i386 instead?
 */
asmlinkage int sys_creat(const char * pathname, int mode)
{
        return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
}
 
#endif
 
void __fput(struct file *filp, struct inode *inode)
{
        if (filp->f_op && filp->f_op->release)
                filp->f_op->release(inode,filp);
        filp->f_inode = NULL;
        if (filp->f_mode & FMODE_WRITE)
                put_write_access(inode);
        iput(inode);
}
 
int close_fp(struct file *filp)
{
        struct inode *inode;
 
        if (filp->f_count == 0) {
                printk("VFS: Close: file count is 0\n");
                return 0;
        }
        inode = filp->f_inode;
        if (inode)
                locks_remove_locks(current, filp);
        fput(filp, inode);
        return 0;
}
 
asmlinkage int sys_close(unsigned int fd)
{
        int error;
        struct file * filp;
        struct files_struct * files;
 
        files = current->files;
        error = -EBADF;
        if (fd < NR_OPEN && (filp = files->fd[fd]) != NULL) {
                put_unused_fd(fd);
                FD_CLR(fd, &files->close_on_exec);
                files->fd[fd] = NULL;
                error = close_fp(filp);
        }
        return error;
}
 
/*
 * This routine simulates a hangup on the tty, to arrange that users
 * are given clean terminals at login time.
 */
asmlinkage int sys_vhangup(void)
{
        if (!suser())
                return -EPERM;
        /* If there is a controlling tty, hang it up */
        if (current->tty)
                tty_vhangup(current->tty);
        return 0;
}

Browse

Tools

Subversion Repositories or1k_old

[/] [or1k_old/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [open.c] - Blame information for rev 1782

Line No.	Rev	Author	Line
1	199	simons	`/*`
2			`* linux/fs/open.c`
3			`*`
4			`* Copyright (C) 1991, 1992 Linus Torvalds`
5			`*/`
6
7			`/*`
8			`* uClinux revisions for NO_MM`
9			`* Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>,`
10			`* The Silver Hammer Group, Ltd.`
11			`*/`
12
13			`#include <linux/vfs.h>`
14			`#include <linux/types.h>`
15			`#include <linux/utime.h>`
16			`#include <linux/errno.h>`
17			`#include <linux/fcntl.h>`
18			`#include <linux/stat.h>`
19			`#include <linux/string.h>`
20			`#include <linux/sched.h>`
21			`#include <linux/kernel.h>`
22			`#include <linux/signal.h>`
23			`#include <linux/tty.h>`
24			`#include <linux/time.h>`
25			`#include <linux/mm.h>`
26			`#include <linux/file.h>`
27
28			`#include <asm/segment.h>`
29			`#include <asm/bitops.h>`
30
31			`asmlinkage int sys_statfs(const char * path, struct statfs * buf)`
32			`{`
33			`struct inode * inode;`
34			`int error;`
35
36			`error = verify_area(VERIFY_WRITE, buf, sizeof(struct statfs));`
37			`if (error)`
38			`return error;`
39			`error = namei(path,&inode);`
40			`if (error)`
41			`return error;`
42			`if (!inode->i_sb->s_op->statfs) {`
43			`iput(inode);`
44			`return -ENOSYS;`
45			`}`
46			`inode->i_sb->s_op->statfs(inode->i_sb, buf, sizeof(struct statfs));`
47			`iput(inode);`
48			`return 0;`
49			`}`
50
51			`asmlinkage int sys_fstatfs(unsigned int fd, struct statfs * buf)`
52			`{`
53			`struct inode * inode;`
54			`struct file * file;`
55			`int error;`
56
57			`error = verify_area(VERIFY_WRITE, buf, sizeof(struct statfs));`
58			`if (error)`
59			`return error;`
60			`if (fd >= NR_OPEN \|\| !(file = current->files->fd[fd]))`
61			`return -EBADF;`
62			`if (!(inode = file->f_inode))`
63			`return -ENOENT;`
64			`if (!inode->i_sb)`
65			`return -ENODEV;`
66			`if (!inode->i_sb->s_op->statfs)`
67			`return -ENOSYS;`
68			`inode->i_sb->s_op->statfs(inode->i_sb, buf, sizeof(struct statfs));`
69			`return 0;`
70			`}`
71
72			`int do_truncate(struct inode *inode, unsigned long length)`
73			`{`
74			`int error;`
75			`struct iattr newattrs;`
76
77			`/* Not pretty: "inode->i_size" shouldn't really be "off_t". But it is. */`
78			`if ((off_t) length < 0)`
79			`return -EINVAL;`
80
81			`down(&inode->i_sem);`
82			`newattrs.ia_size = length;`
83			`newattrs.ia_valid = ATTR_SIZE \| ATTR_CTIME;`
84			`error = notify_change(inode, &newattrs);`
85			`if (!error) {`
86			`/* truncate virtual mappings of this file */`
87			`#ifndef NO_MM`
88			`vmtruncate(inode, length);`
89			`#endif /* !NO_MM */`
90			`if (inode->i_op && inode->i_op->truncate)`
91			`inode->i_op->truncate(inode);`
92			`}`
93			`up(&inode->i_sem);`
94			`return error;`
95			`}`
96
97			`asmlinkage int sys_truncate(const char * path, unsigned long length)`
98			`{`
99			`struct inode * inode;`
100			`int error;`
101
102			`error = namei(path,&inode);`
103			`if (error)`
104			`return error;`
105
106			`error = -EACCES;`
107			`if (S_ISDIR(inode->i_mode))`
108			`goto out;`
109
110			`error = permission(inode,MAY_WRITE);`
111			`if (error)`
112			`goto out;`
113
114			`error = -EROFS;`
115			`if (IS_RDONLY(inode))`
116			`goto out;`
117
118			`error = -EPERM;`
119			`if (IS_IMMUTABLE(inode) \|\| IS_APPEND(inode))`
120			`goto out;`
121
122			`error = get_write_access(inode);`
123			`if (error)`
124			`goto out;`
125
126			`error = locks_verify_area(FLOCK_VERIFY_WRITE, inode, NULL,`
127			`length < inode->i_size ? length : inode->i_size,`
128			`abs(inode->i_size - length));`
129			`if (!error) {`
130			`if (inode->i_sb && inode->i_sb->dq_op)`
131			`inode->i_sb->dq_op->initialize(inode, -1);`
132			`error = do_truncate(inode, length);`
133			`}`
134			`put_write_access(inode);`
135			`out:`
136			`iput(inode);`
137			`return error;`
138			`}`
139
140			`asmlinkage int sys_ftruncate(unsigned int fd, unsigned long length)`
141			`{`
142			`struct inode * inode;`
143			`struct file * file;`
144			`int error;`
145
146			`if (fd >= NR_OPEN \|\| !(file = current->files->fd[fd]))`
147			`return -EBADF;`
148			`if (!(inode = file->f_inode))`
149			`return -ENOENT;`
150			`if (S_ISDIR(inode->i_mode) \|\| !(file->f_mode & FMODE_WRITE))`
151			`return -EACCES;`
152			`if (IS_IMMUTABLE(inode) \|\| IS_APPEND(inode))`
153			`return -EPERM;`
154			`error = locks_verify_area(FLOCK_VERIFY_WRITE, inode, file,`
155			`length < inode->i_size ? length : inode->i_size,`
156			`abs(inode->i_size - length));`
157			`if (!error)`
158			`error = do_truncate(inode, length);`
159			`return error;`
160			`}`
161
162			`#ifndef __alpha__`
163
164			`/*`
165			`* sys_utime() can be implemented in user-level using sys_utimes().`
166			`* Is this for backwards compatibility? If so, why not move it`
167			`* into the appropriate arch directory (for those architectures that`
168			`* need it).`
169			`*/`
170
171			`/* If times==NULL, set access and modification to current time,`
172			`* must be owner or have write permission.`
173			`* Else, update from *times, must be owner or super user.`
174			`*/`
175			`asmlinkage int sys_utime(char * filename, struct utimbuf * times)`
176			`{`
177			`int error;`
178			`struct inode * inode;`
179			`struct iattr newattrs;`
180
181			`error = namei(filename,&inode);`
182			`if (error)`
183			`return error;`
184			`if (IS_RDONLY(inode)) {`
185			`iput(inode);`
186			`return -EROFS;`
187			`}`
188			`/* Don't worry, the checks are done in inode_change_ok() */`
189			`newattrs.ia_valid = ATTR_CTIME \| ATTR_MTIME \| ATTR_ATIME;`
190			`if (times) {`
191			`error = verify_area(VERIFY_READ, times, sizeof(*times));`
192			`if (error) {`
193			`iput(inode);`
194			`return error;`
195			`}`
196			`newattrs.ia_atime = get_user(&times->actime);`
197			`newattrs.ia_mtime = get_user(&times->modtime);`
198			`newattrs.ia_valid \|= ATTR_ATIME_SET \| ATTR_MTIME_SET;`
199			`} else {`
200			`if (current->fsuid != inode->i_uid &&`
201			`(error = permission(inode,MAY_WRITE)) != 0) {`
202			`iput(inode);`
203			`return error;`
204			`}`
205			`}`
206			`error = notify_change(inode, &newattrs);`
207			`iput(inode);`
208			`return error;`
209			`}`
210
211			`#endif`
212
213			`/* If times==NULL, set access and modification to current time,`
214			`* must be owner or have write permission.`
215			`* Else, update from *times, must be owner or super user.`
216			`*/`
217			`asmlinkage int sys_utimes(char * filename, struct timeval * utimes)`
218			`{`
219			`int error;`
220			`struct inode * inode;`
221			`struct iattr newattrs;`
222
223			`error = namei(filename,&inode);`
224			`if (error)`
225			`return error;`
226			`if (IS_RDONLY(inode)) {`
227			`iput(inode);`
228			`return -EROFS;`
229			`}`
230			`/* Don't worry, the checks are done in inode_change_ok() */`
231			`newattrs.ia_valid = ATTR_CTIME \| ATTR_MTIME \| ATTR_ATIME;`
232			`if (utimes) {`
233			`struct timeval times[2];`
234			`error = verify_area(VERIFY_READ, utimes, sizeof(times));`
235			`if (error) {`
236			`iput(inode);`
237			`return error;`
238			`}`
239			`memcpy_fromfs(&times, utimes, sizeof(times));`
240			`newattrs.ia_atime = times[0].tv_sec;`
241			`newattrs.ia_mtime = times[1].tv_sec;`
242			`newattrs.ia_valid \|= ATTR_ATIME_SET \| ATTR_MTIME_SET;`
243			`} else {`
244			`if ((error = permission(inode,MAY_WRITE)) != 0) {`
245			`iput(inode);`
246			`return error;`
247			`}`
248			`}`
249			`error = notify_change(inode, &newattrs);`
250			`iput(inode);`
251			`return error;`
252			`}`
253
254			`/*`
255			`* access() needs to use the real uid/gid, not the effective uid/gid.`
256			`* We do this by temporarily setting fsuid/fsgid to the wanted values`
257			`*/`
258			`asmlinkage int sys_access(const char * filename, int mode)`
259			`{`
260			`struct inode * inode;`
261			`int old_fsuid, old_fsgid;`
262			`int res;`
263
264			`if (mode != (mode & S_IRWXO)) /* where's F_OK, X_OK, W_OK, R_OK? */`
265			`return -EINVAL;`
266			`old_fsuid = current->fsuid;`
267			`old_fsgid = current->fsgid;`
268			`current->fsuid = current->uid;`
269			`current->fsgid = current->gid;`
270			`res = namei(filename,&inode);`
271			`if (!res) {`
272			`res = permission(inode, mode);`
273			`iput(inode);`
274			`}`
275			`current->fsuid = old_fsuid;`
276			`current->fsgid = old_fsgid;`
277			`return res;`
278			`}`
279
280			`asmlinkage int sys_chdir(const char * filename)`
281			`{`
282			`struct inode * inode;`
283			`int error;`
284
285			`error = namei(filename,&inode);`
286			`if (error)`
287			`return error;`
288			`if (!S_ISDIR(inode->i_mode)) {`
289			`iput(inode);`
290			`return -ENOTDIR;`
291			`}`
292			`if ((error = permission(inode,MAY_EXEC)) != 0) {`
293			`iput(inode);`
294			`return error;`
295			`}`
296			`iput(current->fs->pwd);`
297			`current->fs->pwd = inode;`
298			`return (0);`
299			`}`
300
301			`asmlinkage int sys_fchdir(unsigned int fd)`
302			`{`
303			`struct inode * inode;`
304			`struct file * file;`
305			`int error;`
306
307			`if (fd >= NR_OPEN \|\| !(file = current->files->fd[fd]))`
308			`return -EBADF;`
309			`if (!(inode = file->f_inode))`
310			`return -ENOENT;`
311			`if (!S_ISDIR(inode->i_mode))`
312			`return -ENOTDIR;`
313			`if ((error = permission(inode,MAY_EXEC)) != 0)`
314			`return error;`
315			`iput(current->fs->pwd);`
316			`current->fs->pwd = inode;`
317			`inode->i_count++;`
318			`return (0);`
319			`}`
320
321			`asmlinkage int sys_chroot(const char * filename)`
322			`{`
323			`struct inode * inode;`
324			`int error;`
325
326			`error = namei(filename,&inode);`
327			`if (error)`
328			`return error;`
329			`if (!S_ISDIR(inode->i_mode)) {`
330			`iput(inode);`
331			`return -ENOTDIR;`
332			`}`
333			`if (!fsuser()) {`
334			`iput(inode);`
335			`return -EPERM;`
336			`}`
337			`iput(current->fs->root);`
338			`current->fs->root = inode;`
339			`return (0);`
340			`}`
341
342			`asmlinkage int sys_fchmod(unsigned int fd, mode_t mode)`
343			`{`
344			`struct inode * inode;`
345			`struct file * file;`
346			`struct iattr newattrs;`
347
348			`if (fd >= NR_OPEN \|\| !(file = current->files->fd[fd]))`
349			`return -EBADF;`
350			`if (!(inode = file->f_inode))`
351			`return -ENOENT;`
352			`if (IS_RDONLY(inode))`
353			`return -EROFS;`
354			`if (IS_IMMUTABLE(inode) \|\| IS_APPEND(inode))`
355			`return -EPERM;`
356			`if (mode == (mode_t) -1)`
357			`mode = inode->i_mode;`
358			`newattrs.ia_mode = (mode & S_IALLUGO) \| (inode->i_mode & ~S_IALLUGO);`
359			`newattrs.ia_valid = ATTR_MODE \| ATTR_CTIME;`
360			`inode->i_dirt = 1;`
361			`return notify_change(inode, &newattrs);`
362			`}`
363
364			`asmlinkage int sys_chmod(const char * filename, mode_t mode)`
365			`{`
366			`struct inode * inode;`
367			`int error;`
368			`struct iattr newattrs;`
369
370			`error = namei(filename,&inode);`
371			`if (error)`
372			`return error;`
373			`if (IS_RDONLY(inode)) {`
374			`iput(inode);`
375			`return -EROFS;`
376			`}`
377			`if (IS_IMMUTABLE(inode) \|\| IS_APPEND(inode)) {`
378			`iput(inode);`
379			`return -EPERM;`
380			`}`
381			`if (mode == (mode_t) -1)`
382			`mode = inode->i_mode;`
383			`newattrs.ia_mode = (mode & S_IALLUGO) \| (inode->i_mode & ~S_IALLUGO);`
384			`newattrs.ia_valid = ATTR_MODE \| ATTR_CTIME;`
385			`inode->i_dirt = 1;`
386			`error = notify_change(inode, &newattrs);`
387			`iput(inode);`
388			`return error;`
389			`}`
390
391			`asmlinkage int sys_fchown(unsigned int fd, uid_t user, gid_t group)`
392			`{`
393			`struct inode * inode;`
394			`struct file * file;`
395			`struct iattr newattrs;`
396			`int error;`
397
398			`if (fd >= NR_OPEN \|\| !(file = current->files->fd[fd]))`
399			`return -EBADF;`
400			`if (!(inode = file->f_inode))`
401			`return -ENOENT;`
402			`if (IS_RDONLY(inode))`
403			`return -EROFS;`
404			`if (IS_IMMUTABLE(inode) \|\| IS_APPEND(inode))`
405			`return -EPERM;`
406			`if (user == (uid_t) -1)`
407			`user = inode->i_uid;`
408			`if (group == (gid_t) -1)`
409			`group = inode->i_gid;`
410			`newattrs.ia_mode = inode->i_mode;`
411			`newattrs.ia_uid = user;`
412			`newattrs.ia_gid = group;`
413			`newattrs.ia_valid = ATTR_UID \| ATTR_GID \| ATTR_CTIME;`
414			`/*`
415			`* If the owner has been changed, remove the setuid bit`
416			`*/`
417			`if (inode->i_mode & S_ISUID) {`
418			`newattrs.ia_mode &= ~S_ISUID;`
419			`newattrs.ia_valid \|= ATTR_MODE;`
420			`}`
421			`/*`
422			`* If the group has been changed, remove the setgid bit`
423			`*`
424			`* Don't remove the setgid bit if no group execute bit.`
425			`* This is a file marked for mandatory locking.`
426			`*/`
427			`if (((inode->i_mode & (S_ISGID \| S_IXGRP)) == (S_ISGID \| S_IXGRP))) {`
428			`newattrs.ia_mode &= ~S_ISGID;`
429			`newattrs.ia_valid \|= ATTR_MODE;`
430			`}`
431			`inode->i_dirt = 1;`
432			`if (inode->i_sb && inode->i_sb->dq_op) {`
433			`inode->i_sb->dq_op->initialize(inode, -1);`
434			`if (inode->i_sb->dq_op->transfer(inode, &newattrs, 0))`
435			`return -EDQUOT;`
436			`error = notify_change(inode, &newattrs);`
437			`if (error)`
438			`inode->i_sb->dq_op->transfer(inode, &newattrs, 1);`
439			`} else`
440			`error = notify_change(inode, &newattrs);`
441			`return error;`
442			`}`
443
444			`asmlinkage int sys_chown(const char * filename, uid_t user, gid_t group)`
445			`{`
446			`struct inode * inode;`
447			`int error;`
448			`struct iattr newattrs;`
449
450			`error = lnamei(filename,&inode);`
451			`if (error)`
452			`return error;`
453			`if (IS_RDONLY(inode)) {`
454			`iput(inode);`
455			`return -EROFS;`
456			`}`
457			`if (IS_IMMUTABLE(inode) \|\| IS_APPEND(inode)) {`
458			`iput(inode);`
459			`return -EPERM;`
460			`}`
461			`if (user == (uid_t) -1)`
462			`user = inode->i_uid;`
463			`if (group == (gid_t) -1)`
464			`group = inode->i_gid;`
465			`newattrs.ia_mode = inode->i_mode;`
466			`newattrs.ia_uid = user;`
467			`newattrs.ia_gid = group;`
468			`newattrs.ia_valid = ATTR_UID \| ATTR_GID \| ATTR_CTIME;`
469			`/*`
470			`* If the owner has been changed, remove the setuid bit`
471			`*/`
472			`if (inode->i_mode & S_ISUID) {`
473			`newattrs.ia_mode &= ~S_ISUID;`
474			`newattrs.ia_valid \|= ATTR_MODE;`
475			`}`
476			`/*`
477			`* If the group has been changed, remove the setgid bit`
478			`*`
479			`* Don't remove the setgid bit if no group execute bit.`
480			`* This is a file marked for mandatory locking.`
481			`*/`
482			`if (((inode->i_mode & (S_ISGID \| S_IXGRP)) == (S_ISGID \| S_IXGRP))) {`
483			`newattrs.ia_mode &= ~S_ISGID;`
484			`newattrs.ia_valid \|= ATTR_MODE;`
485			`}`
486			`inode->i_dirt = 1;`
487			`if (inode->i_sb->dq_op) {`
488			`inode->i_sb->dq_op->initialize(inode, -1);`
489			`if (inode->i_sb->dq_op->transfer(inode, &newattrs, 0))`
490			`return -EDQUOT;`
491			`error = notify_change(inode, &newattrs);`
492			`if (error)`
493			`inode->i_sb->dq_op->transfer(inode, &newattrs, 1);`
494			`} else`
495			`error = notify_change(inode, &newattrs);`
496			`iput(inode);`
497			`return(error);`
498			`}`
499
500			`/*`
501			`* Note that while the flag value (low two bits) for sys_open means:`
502			`* 00 - read-only`
503			`* 01 - write-only`
504			`* 10 - read-write`
505			`* 11 - special`
506			`* it is changed into`
507			`* 00 - no permissions needed`
508			`* 01 - read-permission`
509			`* 10 - write-permission`
510			`* 11 - read-write`
511			`* for the internal routines (ie open_namei()/follow_link() etc). 00 is`
512			`* used by symlinks.`
513			`*/`
514			`static int do_open(const char * filename,int flags,int mode, int fd)`
515			`{`
516			`struct inode * inode;`
517			`struct file * f;`
518			`int flag,error;`
519
520			`f = get_empty_filp();`
521
522			`if (!f)`
523			`return -ENFILE;`
524			`f->f_flags = flag = flags;`
525			`f->f_mode = (flag+1) & O_ACCMODE;`
526			`if (f->f_mode)`
527			`flag++;`
528			`if (flag & O_TRUNC)`
529			`flag \|= 2;`
530			`error = open_namei(filename,flag,mode,&inode,NULL);`
531			`if (error)`
532			`goto cleanup_file;`
533			`if (f->f_mode & FMODE_WRITE) {`
534			`error = get_write_access(inode);`
535			`if (error)`
536			`goto cleanup_inode;`
537			`}`
538
539			`f->f_inode = inode;`
540			`f->f_pos = 0;`
541			`f->f_reada = 0;`
542			`f->f_op = NULL;`
543			`if (inode->i_op)`
544			`f->f_op = inode->i_op->default_file_ops;`
545			`if (f->f_op && f->f_op->open) {`
546			`error = f->f_op->open(inode,f);`
547			`if (error)`
548			`goto cleanup_all;`
549			`}`
550			`f->f_flags &= ~(O_CREAT \| O_EXCL \| O_NOCTTY \| O_TRUNC);`
551
552			`current->files->fd[fd] = f;`
553			`return 0;`
554
555			`cleanup_all:`
556			`if (f->f_mode & FMODE_WRITE)`
557			`put_write_access(inode);`
558			`cleanup_inode:`
559			`iput(inode);`
560			`cleanup_file:`
561			`f->f_count--;`
562			`return error;`
563			`}`
564
565			`/*`
566			`* Find a empty file descriptor entry, and mark it busy`
567			`*/`
568			`int get_unused_fd(void)`
569			`{`
570			`int fd;`
571			`struct files_struct * files = current->files;`
572
573			`fd = find_first_zero_bit(&files->open_fds, NR_OPEN);`
574			`if (fd < current->rlim[RLIMIT_NOFILE].rlim_cur) {`
575			`FD_SET(fd, &files->open_fds);`
576			`FD_CLR(fd, &files->close_on_exec);`
577			`return fd;`
578			`}`
579			`return -EMFILE;`
580			`}`
581
582			`inline void put_unused_fd(int fd)`
583			`{`
584			`FD_CLR(fd, &current->files->open_fds);`
585			`}`
586
587			`asmlinkage int sys_open(const char * filename,int flags,int mode)`
588			`{`
589			`char * tmp;`
590			`int fd, error;`
591
592			`fd = get_unused_fd();`
593			`if (fd < 0)`
594			`return fd;`
595			`error = getname(filename, &tmp);`
596			`if (!error) {`
597			`error = do_open(tmp,flags,mode, fd);`
598			`putname(tmp);`
599
600			`if (!error)`
601			`return fd;`
602			`}`
603
604			`put_unused_fd(fd);`
605			`return error;`
606			`}`
607
608			`#ifndef __alpha__`
609
610			`/*`
611			`* For backward compatibility? Maybe this should be moved`
612			`* into arch/i386 instead?`
613			`*/`
614			`asmlinkage int sys_creat(const char * pathname, int mode)`
615			`{`
616			`return sys_open(pathname, O_CREAT \| O_WRONLY \| O_TRUNC, mode);`
617			`}`
618
619			`#endif`
620
621			`void __fput(struct file filp, struct inode inode)`
622			`{`
623			`if (filp->f_op && filp->f_op->release)`
624			`filp->f_op->release(inode,filp);`
625			`filp->f_inode = NULL;`
626			`if (filp->f_mode & FMODE_WRITE)`
627			`put_write_access(inode);`
628			`iput(inode);`
629			`}`
630
631			`int close_fp(struct file *filp)`
632			`{`
633			`struct inode *inode;`
634
635			`if (filp->f_count == 0) {`
636			`printk("VFS: Close: file count is 0\n");`
637			`return 0;`
638			`}`
639			`inode = filp->f_inode;`
640			`if (inode)`
641			`locks_remove_locks(current, filp);`
642			`fput(filp, inode);`
643			`return 0;`
644			`}`
645
646			`asmlinkage int sys_close(unsigned int fd)`
647			`{`
648			`int error;`
649			`struct file * filp;`
650			`struct files_struct * files;`
651
652			`files = current->files;`
653			`error = -EBADF;`
654			`if (fd < NR_OPEN && (filp = files->fd[fd]) != NULL) {`
655			`put_unused_fd(fd);`
656			`FD_CLR(fd, &files->close_on_exec);`
657			`files->fd[fd] = NULL;`
658			`error = close_fp(filp);`
659			`}`
660			`return error;`
661			`}`
662
663			`/*`
664			`* This routine simulates a hangup on the tty, to arrange that users`
665			`* are given clean terminals at login time.`
666			`*/`
667			`asmlinkage int sys_vhangup(void)`
668			`{`
669			`if (!suser())`
670			`return -EPERM;`
671			`/* If there is a controlling tty, hang it up */`
672			`if (current->tty)`
673			`tty_vhangup(current->tty);`
674			`return 0;`
675			`}`