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dm ioctl: introduce ioctl_flags

This patch introduces flags for each ioctl function. So far, one flag is defined, IOCTL_FLAGS_NO_PARAMS. It is set if the function processing the ioctl doesn't take or produce any parameters in the section of the data buffer that has a variable size.

Mikulas Patocka committed 13 years ago

Commit e2914cc1 parent 5f015201 file · +41 −23Browse files

Unified · Split

drivers/md/dm-ioctl.c+41−23
@@ -1478,39 +1478,52 @@ static int target_message(struct dm_ioctl *param, size_t param_size) · 1477 unmodified lines
1478 return r;1478 return r;
1479}1479}
1480 1480
1481/*
1482 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1483 * followed by a data buffer. This flag is set if the second part,
1484 * which has a variable size, is not used by the function processing
1485 * the ioctl.
1486 */
1487#define IOCTL_FLAGS_NO_PARAMS 1
1488
1481/*-----------------------------------------------------------------1489/*-----------------------------------------------------------------
1482 * Implementation of open/close/ioctl on the special char1490 * Implementation of open/close/ioctl on the special char
1483 * device.1491 * device.
1484 *---------------------------------------------------------------*/1492 *---------------------------------------------------------------*/
1485static ioctl_fn lookup_ioctl(unsigned int cmd)1493static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1486{1494{
1487 static struct {1495 static struct {
1488 int cmd;1496 int cmd;
1497 int flags;
1489 ioctl_fn fn;1498 ioctl_fn fn;
1490 } _ioctls[] = {1499 } _ioctls[] = {
1491 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */1500 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1492 {DM_REMOVE_ALL_CMD, remove_all},1501 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all},
1493 {DM_LIST_DEVICES_CMD, list_devices},1502 {DM_LIST_DEVICES_CMD, 0, list_devices},
1494 1503
1495 {DM_DEV_CREATE_CMD, dev_create},1504 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create},
1496 {DM_DEV_REMOVE_CMD, dev_remove},1505 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove},
1497 {DM_DEV_RENAME_CMD, dev_rename},1506 {DM_DEV_RENAME_CMD, 0, dev_rename},
1498 {DM_DEV_SUSPEND_CMD, dev_suspend},1507 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1499 {DM_DEV_STATUS_CMD, dev_status},1508 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1500 {DM_DEV_WAIT_CMD, dev_wait},1509 {DM_DEV_WAIT_CMD, 0, dev_wait},
1501 1510
1502 {DM_TABLE_LOAD_CMD, table_load},1511 {DM_TABLE_LOAD_CMD, 0, table_load},
1503 {DM_TABLE_CLEAR_CMD, table_clear},1512 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1504 {DM_TABLE_DEPS_CMD, table_deps},1513 {DM_TABLE_DEPS_CMD, 0, table_deps},
1505 {DM_TABLE_STATUS_CMD, table_status},1514 {DM_TABLE_STATUS_CMD, 0, table_status},
1506 1515
1507 {DM_LIST_VERSIONS_CMD, list_versions},1516 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1508 1517
1509 {DM_TARGET_MSG_CMD, target_message},1518 {DM_TARGET_MSG_CMD, 0, target_message},
1510 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}1519 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry}
1511 };1520 };
1512 1521
1513 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;1522 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1523 return NULL;
1524
1525 *ioctl_flags = _ioctls[cmd].flags;
1526 return _ioctls[cmd].fn;
1514}1527}
1515 1528
1516/*1529/*
@@ -1652,6 +1665,7 @@ static int validate_params(uint cmd, struct dm_ioctl *param) · 135 unmodified lines
1652static int ctl_ioctl(uint command, struct dm_ioctl __user *user)1665static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1653{1666{
1654 int r = 0;1667 int r = 0;
1668 int ioctl_flags;
1655 int param_flags;1669 int param_flags;
1656 unsigned int cmd;1670 unsigned int cmd;
1657 struct dm_ioctl *uninitialized_var(param);1671 struct dm_ioctl *uninitialized_var(param);
@@ -1681,7 +1695,7 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user) · 23 unmodified lines
1681 if (cmd == DM_VERSION_CMD)1695 if (cmd == DM_VERSION_CMD)
1682 return 0;1696 return 0;
1683 1697
1684 fn = lookup_ioctl(cmd);1698 fn = lookup_ioctl(cmd, &ioctl_flags);
1685 if (!fn) {1699 if (!fn) {
1686 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);1700 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1687 return -ENOTTY;1701 return -ENOTTY;
@@ -1703,6 +1717,10 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user) · 15 unmodified lines
1703 param->data_size = sizeof(*param);1717 param->data_size = sizeof(*param);
1704 r = fn(param, input_param_size);1718 r = fn(param, input_param_size);
1705 1719
1720 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1721 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1722 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1723
1706 /*1724 /*
1707 * Copy the results back to userland.1725 * Copy the results back to userland.
1708 */1726 */