lvm.c

linux和2410结合开发 用他可以生成2410所需的zImage文件

	return;
}	/* lvm_cleanup() */

/*
 * support function to initialize lvm variables
 */
static void __init lvm_init_vars(void)
{
	int v;

	loadtime = CURRENT_TIME;

	lvm_lock = lvm_snapshot_lock = SPIN_LOCK_UNLOCKED;

	pe_lock_req.lock = UNLOCK_PE;
	pe_lock_req.data.lv_dev = 0;
	pe_lock_req.data.pv_dev = 0;
	pe_lock_req.data.pv_offset = 0;

	/* Initialize VG pointers */
	for (v = 0; v < ABS_MAX_VG; v++) vg[v] = NULL;

	/* Initialize LV -> VG association */
	for (v = 0; v < ABS_MAX_LV; v++) {
		/* index ABS_MAX_VG never used for real VG */
		vg_lv_map[v].vg_number = ABS_MAX_VG;
		vg_lv_map[v].lv_number = -1;
	}

	return;
} /* lvm_init_vars() */


/********************************************************************
 *
 * Character device functions
 *
 ********************************************************************/

#define MODE_TO_STR(mode) (mode) & FMODE_READ ? "READ" : "", \
			  (mode) & FMODE_WRITE ? "WRITE" : ""

/*
 * character device open routine
 */
static int lvm_chr_open(struct inode *inode, struct file *file)
{
	unsigned int minor = MINOR(inode->i_rdev);

	P_DEV("chr_open MINOR: %d  VG#: %d  mode: %s%s  lock: %d\n",
	      minor, VG_CHR(minor), MODE_TO_STR(file->f_mode), lock);

	/* super user validation */
	if (!capable(CAP_SYS_ADMIN)) return -EACCES;

	/* Group special file open */
	if (VG_CHR(minor) > MAX_VG) return -ENXIO;

       spin_lock(&lvm_lock);
       if(lock == current->pid)
               _lock_open_count++;
       spin_unlock(&lvm_lock);

	lvm_chr_open_count++;

	MOD_INC_USE_COUNT;

	return 0;
} /* lvm_chr_open() */


/*
 * character device i/o-control routine
 *
 * Only one changing process can do changing ioctl at one time,
 * others will block.
 *
 */
static int lvm_chr_ioctl(struct inode *inode, struct file *file,
		  uint command, ulong a)
{
	int minor = MINOR(inode->i_rdev);
	uint extendable, l, v;
	void *arg = (void *) a;
	lv_t lv;
	vg_t* vg_ptr = vg[VG_CHR(minor)];

	/* otherwise cc will complain about unused variables */
	(void) lvm_lock;

	P_IOCTL("chr MINOR: %d  command: 0x%X  arg: %p  VG#: %d  mode: %s%s\n",
		minor, command, arg, VG_CHR(minor), MODE_TO_STR(file->f_mode));

#ifdef LVM_TOTAL_RESET
	if (lvm_reset_spindown > 0) return -EACCES;
#endif

	/* Main command switch */
	switch (command) {
	case LVM_LOCK_LVM:
		/* lock the LVM */
		return lvm_do_lock_lvm();

	case LVM_GET_IOP_VERSION:
		/* check lvm version to ensure driver/tools+lib
		   interoperability */
		if (copy_to_user(arg, &lvm_iop_version, sizeof(ushort)) != 0)
			return -EFAULT;
		return 0;

#ifdef LVM_TOTAL_RESET
	case LVM_RESET:
		/* lock reset function */
		lvm_reset_spindown = 1;
		for (v = 0; v < ABS_MAX_VG; v++) {
			if (vg[v] != NULL) lvm_do_vg_remove(v);
		}

#ifdef MODULE
		while (GET_USE_COUNT(&__this_module) < 1)
			MOD_INC_USE_COUNT;
		while (GET_USE_COUNT(&__this_module) > 1)
			MOD_DEC_USE_COUNT;
#endif /* MODULE */
		lock = 0;	/* release lock */
		wake_up_interruptible(&lvm_wait);
		return 0;
#endif /* LVM_TOTAL_RESET */


	case LE_REMAP:
		/* remap a logical extent (after moving the physical extent) */
		return lvm_do_le_remap(vg_ptr,arg);

	case PE_LOCK_UNLOCK:
		/* lock/unlock i/o to a physical extent to move it to another
		   physical volume (move's done in user space's pvmove) */
		return lvm_do_pe_lock_unlock(vg_ptr,arg);

	case VG_CREATE_OLD:
		/* create a VGDA */
		return lvm_do_vg_create(arg, minor);

       case VG_CREATE:
               /* create a VGDA, assume VG number is filled in */
		return lvm_do_vg_create(arg, -1);

	case VG_EXTEND:
		/* extend a volume group */
		return lvm_do_vg_extend(vg_ptr, arg);

	case VG_REDUCE:
		/* reduce a volume group */
		return lvm_do_vg_reduce(vg_ptr, arg);

	case VG_RENAME:
		/* rename a volume group */
		return lvm_do_vg_rename(vg_ptr, arg);

	case VG_REMOVE:
		/* remove an inactive VGDA */
		return lvm_do_vg_remove(minor);


	case VG_SET_EXTENDABLE:
		/* set/clear extendability flag of volume group */
		if (vg_ptr == NULL) return -ENXIO;
		if (copy_from_user(&extendable, arg, sizeof(extendable)) != 0)
			return -EFAULT;

		if (extendable == VG_EXTENDABLE ||
		    extendable == ~VG_EXTENDABLE) {
			if (extendable == VG_EXTENDABLE)
				vg_ptr->vg_status |= VG_EXTENDABLE;
			else
				vg_ptr->vg_status &= ~VG_EXTENDABLE;
		} else return -EINVAL;
		return 0;


	case VG_STATUS:
		/* get volume group data (only the vg_t struct) */
		if (vg_ptr == NULL) return -ENXIO;
		if (copy_to_user(arg, vg_ptr, sizeof(vg_t)) != 0)
			return -EFAULT;
		return 0;


	case VG_STATUS_GET_COUNT:
		/* get volume group count */
		if (copy_to_user(arg, &vg_count, sizeof(vg_count)) != 0)
			return -EFAULT;
		return 0;


	case VG_STATUS_GET_NAMELIST:
		/* get volume group names */
		for (l = v = 0; v < ABS_MAX_VG; v++) {
			if (vg[v] != NULL) {
				if (copy_to_user(arg + l * NAME_LEN,
						 vg[v]->vg_name,
						 NAME_LEN) != 0)
					return -EFAULT;
				l++;
			}
		}
		return 0;


	case LV_CREATE:
	case LV_EXTEND:
	case LV_REDUCE:
	case LV_REMOVE:
	case LV_RENAME:
		/* create, extend, reduce, remove or rename a logical volume */
		if (vg_ptr == NULL) return -ENXIO;
		if (copy_from_user(&lv_req, arg, sizeof(lv_req)) != 0)
			return -EFAULT;

		if (command != LV_REMOVE) {
			if (copy_from_user(&lv, lv_req.lv, sizeof(lv_t)) != 0)
				return -EFAULT;
		}
		switch (command) {
		case LV_CREATE:
			return lvm_do_lv_create(minor, lv_req.lv_name, &lv);

		case LV_EXTEND:
		case LV_REDUCE:
			return lvm_do_lv_extend_reduce(minor, lv_req.lv_name, &lv);
		case LV_REMOVE:
			return lvm_do_lv_remove(minor, lv_req.lv_name, -1);

		case LV_RENAME:
			return lvm_do_lv_rename(vg_ptr, &lv_req, &lv);
		}




	case LV_STATUS_BYNAME:
		/* get status of a logical volume by name */
		return lvm_do_lv_status_byname(vg_ptr, arg);


	case LV_STATUS_BYINDEX:
		/* get status of a logical volume by index */
		return lvm_do_lv_status_byindex(vg_ptr, arg);


	case LV_STATUS_BYDEV:
		/* get status of a logical volume by device */
		return lvm_do_lv_status_bydev(vg_ptr, arg);


	case PV_CHANGE:
		/* change a physical volume */
		return lvm_do_pv_change(vg_ptr,arg);


	case PV_STATUS:
		/* get physical volume data (pv_t structure only) */
		return lvm_do_pv_status(vg_ptr,arg);


	case PV_FLUSH:
		/* physical volume buffer flush/invalidate */
               return lvm_do_pv_flush(arg);


	default:
		printk(KERN_WARNING
		       "%s -- lvm_chr_ioctl: unknown command 0x%x\n",
		       lvm_name, command);
		return -EINVAL;
	}

	return 0;
} /* lvm_chr_ioctl */


/*
 * character device close routine
 */
static int lvm_chr_close(struct inode *inode, struct file *file)
{
	P_DEV("chr_close MINOR: %d  VG#: %d\n",
	      MINOR(inode->i_rdev), VG_CHR(MINOR(inode->i_rdev)));

#ifdef LVM_TOTAL_RESET
	if (lvm_reset_spindown > 0) {
		lvm_reset_spindown = 0;
		lvm_chr_open_count = 0;
	}
#endif

	if (lvm_chr_open_count > 0) lvm_chr_open_count--;

       spin_lock(&lvm_lock);
       if(lock == current->pid) {
               if(!_lock_open_count) {
			P_DEV("chr_close: unlocking LVM for pid %d\n", lock);
                       lock = 0;
                       wake_up_interruptible(&lvm_wait);
               } else
                       _lock_open_count--;
	}
       spin_unlock(&lvm_lock);

	MOD_DEC_USE_COUNT;

	return 0;
} /* lvm_chr_close() */



/********************************************************************
 *
 * Block device functions
 *
 ********************************************************************/

/*
 * block device open routine
 */
static int lvm_blk_open(struct inode *inode, struct file *file)
{
	int minor = MINOR(inode->i_rdev);
	lv_t *lv_ptr;
	vg_t *vg_ptr = vg[VG_BLK(minor)];

	P_DEV("blk_open MINOR: %d  VG#: %d  LV#: %d  mode: %s%s\n",
	      minor, VG_BLK(minor), LV_BLK(minor), MODE_TO_STR(file->f_mode));

#ifdef LVM_TOTAL_RESET
	if (lvm_reset_spindown > 0)
		return -EPERM;
#endif

	if (vg_ptr != NULL &&
	    (vg_ptr->vg_status & VG_ACTIVE) &&
	    (lv_ptr = vg_ptr->lv[LV_BLK(minor)]) != NULL &&
	    LV_BLK(minor) >= 0 &&
	    LV_BLK(minor) < vg_ptr->lv_max) {

		/* Check parallel LV spindown (LV remove) */
		if (lv_ptr->lv_status & LV_SPINDOWN) return -EPERM;

		/* Check inactive LV and open for read/write */
		/* We need to be able to "read" an inactive LV
		   to re-activate it again */
		if ((file->f_mode & FMODE_WRITE) &&
		    (!(lv_ptr->lv_status & LV_ACTIVE)))
		    return -EPERM;

		if (!(lv_ptr->lv_access & LV_WRITE) &&
		    (file->f_mode & FMODE_WRITE))
			return -EACCES;


                /* be sure to increment VG counter */
		if (lv_ptr->lv_open == 0) vg_ptr->lv_open++;
		lv_ptr->lv_open++;

		MOD_INC_USE_COUNT;

		P_DEV("blk_open OK, LV size %d\n", lv_ptr->lv_size);

		return 0;
	}
	return -ENXIO;
} /* lvm_blk_open() */


/*
 * block device i/o-control routine
 */
static int lvm_blk_ioctl(struct inode *inode, struct file *file,
			 uint command, ulong a)
{
	int minor = MINOR(inode->i_rdev);
	vg_t *vg_ptr = vg[VG_BLK(minor)];
	lv_t *lv_ptr = vg_ptr->lv[LV_BLK(minor)];
	void *arg = (void *) a;
	struct hd_geometry *hd = (struct hd_geometry *) a;

	P_IOCTL("blk MINOR: %d  command: 0x%X  arg: %p  VG#: %d  LV#: %d  "
		"mode: %s%s\n", minor, command, arg, VG_BLK(minor),
		LV_BLK(minor), MODE_TO_STR(file->f_mode));

	switch (command) {
	case BLKSSZGET:
		/* get block device sector size as needed e.g. by fdisk */
		return put_user(get_hardsect_size(inode->i_rdev), (int *) arg);

	case BLKGETSIZE:
		/* return device size */
		P_IOCTL("BLKGETSIZE: %u\n", lv_ptr->lv_size);
		if (put_user(lv_ptr->lv_size, (unsigned long *)arg))
			return -EFAULT;
		break;

	case BLKGETSIZE64:
		if (put_user((u64)lv_ptr->lv_size << 9, (u64 *)arg))
			return -EFAULT;
		break;


	case BLKFLSBUF:
		/* flush buffer cache */
		if (!capable(CAP_SYS_ADMIN)) return -EACCES;

		P_IOCTL("BLKFLSBUF\n");

		fsync_dev(inode->i_rdev);
		invalidate_buffers(inode->i_rdev);
		break;


	case BLKRASET:
		/* set read ahead for block device */
		if (!capable(CAP_SYS_ADMIN)) return -EACCES;

		P_IOCTL("BLKRASET: %ld sectors for %s\n",
			(long) arg, kdevname(inode->i_rdev));

		if ((long) arg < LVM_MIN_READ_AHEAD ||
		    (long) arg > LVM_MAX_READ_AHEAD)
			return -EINVAL;
		lv_ptr->lv_read_ahead = (long) arg;
		break;


	case BLKRAGET:
		/* get current read ahead setting */
		P_IOCTL("BLKRAGET %d\n", lv_ptr->lv_read_ahead);
		if (put_user(lv_ptr->lv_read_ahead, (long *)arg))
			return -EFAULT;
		break;


	case HDIO_GETGEO:
		/* get disk geometry */
		P_IOCTL("%s -- lvm_blk_ioctl -- HDIO_GETGEO\n", lvm_name);
		if (hd == NULL)
			return -EINVAL;
		{
			unsigned char heads = 64;
			unsigned char sectors = 32;
			long start = 0;
			short cylinders = lv_ptr->lv_size / heads / sectors;

			if (copy_to_user((char *) &hd->heads, &heads,
					 sizeof(heads)) != 0 ||
			    copy_to_user((char *) &hd->sectors, &sectors,
					 sizeof(sectors)) != 0 ||
			    copy_to_user((short *) &hd->cylinders,
				   &cylinders, sizeof(cylinders)) != 0 ||
			    copy_to_user((long *) &hd->start, &start,
					 sizeof(start)) != 0)
				return -EFAULT;

			P_IOCTL("%s -- lvm_blk_ioctl -- cylinders: %d\n",
				lvm_name, cylinders);
		}
		break;