minix/servers/vfs/stadir.c
2012-03-25 21:58:14 +02:00

287 lines
8.1 KiB
C

/* This file contains the code for performing four system calls relating to
* status and directories.
*
* The entry points into this file are
* do_chdir: perform the CHDIR system call
* do_chroot: perform the CHROOT system call
* do_lstat: perform the LSTAT system call
* do_stat: perform the STAT system call
* do_fstat: perform the FSTAT system call
* do_fstatfs: perform the FSTATFS system call
* do_statvfs: perform the STATVFS system call
* do_fstatvfs: perform the FSTATVFS system call
*/
#include "fs.h"
#include <sys/stat.h>
#include <sys/statfs.h>
#include <minix/com.h>
#include <minix/u64.h>
#include <string.h>
#include "file.h"
#include "fproc.h"
#include "path.h"
#include "param.h"
#include <minix/vfsif.h>
#include <minix/callnr.h>
#include "vnode.h"
#include "vmnt.h"
static int change(struct vnode **iip, char *name_ptr, int len);
static int change_into(struct vnode **iip, struct vnode *vp);
/*===========================================================================*
* do_fchdir *
*===========================================================================*/
int do_fchdir()
{
/* Change directory on already-opened fd. */
struct filp *rfilp;
int r;
/* Is the file descriptor valid? */
if ((rfilp = get_filp(m_in.fd, VNODE_READ)) == NULL) return(err_code);
r = change_into(&fp->fp_wd, rfilp->filp_vno);
unlock_filp(rfilp);
return(r);
}
/*===========================================================================*
* do_chdir *
*===========================================================================*/
int do_chdir()
{
/* Perform the chdir(name) system call. */
return change(&fp->fp_wd, m_in.name, m_in.name_length);
}
/*===========================================================================*
* do_chroot *
*===========================================================================*/
int do_chroot()
{
/* Perform the chroot(name) system call. */
if (!super_user) return(EPERM); /* only su may chroot() */
return change(&fp->fp_rd, m_in.name, m_in.name_length);
}
/*===========================================================================*
* change *
*===========================================================================*/
static int change(iip, name_ptr, len)
struct vnode **iip; /* pointer to the inode pointer for the dir */
char *name_ptr; /* pointer to the directory name to change to */
int len; /* length of the directory name string */
{
/* Do the actual work for chdir() and chroot(). */
struct vnode *vp;
struct vmnt *vmp;
char fullpath[PATH_MAX];
struct lookup resolve;
int r;
lookup_init(&resolve, fullpath, PATH_NOFLAGS, &vmp, &vp);
resolve.l_vmnt_lock = VMNT_READ;
resolve.l_vnode_lock = VNODE_READ;
/* Try to open the directory */
if (fetch_name(name_ptr, len, M3, fullpath) != OK) return(err_code);
if ((vp = eat_path(&resolve, fp)) == NULL) return(err_code);
r = change_into(iip, vp);
unlock_vnode(vp);
unlock_vmnt(vmp);
put_vnode(vp);
return(r);
}
/*===========================================================================*
* change_into *
*===========================================================================*/
static int change_into(iip, vp)
struct vnode **iip; /* pointer to the inode pointer for the dir */
struct vnode *vp; /* this is what the inode has to become */
{
int r;
if (*iip == vp) return(OK); /* Nothing to do */
/* It must be a directory and also be searchable */
if ((vp->v_mode & I_TYPE) != I_DIRECTORY)
r = ENOTDIR;
else
r = forbidden(fp, vp, X_BIT); /* Check if dir is searchable*/
if (r != OK) return(r);
/* Everything is OK. Make the change. */
put_vnode(*iip); /* release the old directory */
dup_vnode(vp);
*iip = vp; /* acquire the new one */
return(OK);
}
/*===========================================================================*
* do_stat *
*===========================================================================*/
int do_stat()
{
/* Perform the stat(name, buf) system call. */
int r;
struct vnode *vp;
struct vmnt *vmp;
char fullpath[PATH_MAX];
struct lookup resolve;
int old_stat = 0;
lookup_init(&resolve, fullpath, PATH_NOFLAGS, &vmp, &vp);
resolve.l_vmnt_lock = VMNT_READ;
resolve.l_vnode_lock = VNODE_READ;
if (call_nr == PREV_STAT)
old_stat = 1;
if (fetch_name(m_in.name1, m_in.name1_length, M1, fullpath) != OK)
return(err_code);
if ((vp = eat_path(&resolve, fp)) == NULL) return(err_code);
r = req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0, old_stat);
unlock_vnode(vp);
unlock_vmnt(vmp);
put_vnode(vp);
return r;
}
/*===========================================================================*
* do_fstat *
*===========================================================================*/
int do_fstat()
{
/* Perform the fstat(fd, buf) system call. */
register struct filp *rfilp;
int r;
int pipe_pos = 0;
int old_stat = 0;
if (call_nr == PREV_FSTAT)
old_stat = 1;
/* Is the file descriptor valid? */
if ((rfilp = get_filp(m_in.fd, VNODE_READ)) == NULL) return(err_code);
/* If we read from a pipe, send position too */
if (rfilp->filp_vno->v_pipe == I_PIPE) {
if (rfilp->filp_mode & R_BIT)
if (ex64hi(rfilp->filp_pos) != 0) {
panic("do_fstat: bad position in pipe");
}
pipe_pos = ex64lo(rfilp->filp_pos);
}
r = req_stat(rfilp->filp_vno->v_fs_e, rfilp->filp_vno->v_inode_nr,
who_e, m_in.buffer, pipe_pos, old_stat);
unlock_filp(rfilp);
return(r);
}
/*===========================================================================*
* do_fstatfs *
*===========================================================================*/
int do_fstatfs()
{
/* Perform the fstatfs(fd, buf) system call. */
struct filp *rfilp;
int r;
/* Is the file descriptor valid? */
if( (rfilp = get_filp(m_in.fd, VNODE_READ)) == NULL) return(err_code);
r = req_fstatfs(rfilp->filp_vno->v_fs_e, who_e, m_in.buffer);
unlock_filp(rfilp);
return(r);
}
/*===========================================================================*
* do_statvfs *
*===========================================================================*/
int do_statvfs()
{
/* Perform the stat(name, buf) system call. */
int r;
struct vnode *vp;
struct vmnt *vmp;
char fullpath[PATH_MAX];
struct lookup resolve;
lookup_init(&resolve, fullpath, PATH_NOFLAGS, &vmp, &vp);
resolve.l_vmnt_lock = VMNT_READ;
resolve.l_vnode_lock = VNODE_READ;
if (fetch_name(m_in.STATVFS_NAME, m_in.STATVFS_LEN, M1, fullpath) != OK)
return(err_code);
if ((vp = eat_path(&resolve, fp)) == NULL) return(err_code);
r = req_statvfs(vp->v_fs_e, who_e, m_in.STATVFS_BUF);
unlock_vnode(vp);
unlock_vmnt(vmp);
put_vnode(vp);
return r;
}
/*===========================================================================*
* do_fstatvfs *
*===========================================================================*/
int do_fstatvfs()
{
/* Perform the fstat(fd, buf) system call. */
register struct filp *rfilp;
int r;
/* Is the file descriptor valid? */
if ((rfilp = get_filp(m_in.FSTATVFS_FD, VNODE_READ)) == NULL)
return(err_code);
r = req_statvfs(rfilp->filp_vno->v_fs_e, who_e, m_in.FSTATVFS_BUF);
unlock_filp(rfilp);
return(r);
}
/*===========================================================================*
* do_lstat *
*===========================================================================*/
int do_lstat()
{
/* Perform the lstat(name, buf) system call. */
struct vnode *vp;
struct vmnt *vmp;
int r;
char fullpath[PATH_MAX];
struct lookup resolve;
int old_stat = 0;
lookup_init(&resolve, fullpath, PATH_RET_SYMLINK, &vmp, &vp);
resolve.l_vmnt_lock = VMNT_READ;
resolve.l_vnode_lock = VNODE_READ;
if (call_nr == PREV_LSTAT)
old_stat = 1;
if (fetch_name(m_in.name1, m_in.name1_length, M1, fullpath) != OK)
return(err_code);
if ((vp = eat_path(&resolve, fp)) == NULL) return(err_code);
r = req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0, old_stat);
unlock_vnode(vp);
unlock_vmnt(vmp);
put_vnode(vp);
return(r);
}