The four simplest IOCTL's allow to create new filters, remove them and pass control commands specific to each target.
Signed-off-by: Sergei Shtepa <[email protected]> --- drivers/md/Makefile | 2 +- drivers/md/dm-ioctl.c | 22 ++++++++++++++++++++++ drivers/md/flt-ctl.c | 25 +++++++++++++++++++++++++ drivers/md/flt-ctl.h | 10 ++++++++++ include/uapi/linux/dm-ioctl.h | 18 ++++++++++++++++-- 5 files changed, 74 insertions(+), 3 deletions(-) create mode 100644 drivers/md/flt-ctl.c create mode 100644 drivers/md/flt-ctl.h diff --git a/drivers/md/Makefile b/drivers/md/Makefile index bd5b38bee82e..1b650950adc1 100644 --- a/drivers/md/Makefile +++ b/drivers/md/Makefile @@ -5,7 +5,7 @@ dm-mod-y += dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \ dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o dm-stats.o \ - dm-rq.o dm-interposer.o + dm-rq.o dm-interposer.o flt-ctl.o dm-multipath-y += dm-path-selector.o dm-mpath.o dm-historical-service-time-y += dm-ps-historical-service-time.o dm-io-affinity-y += dm-ps-io-affinity.o diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 2bcb316144a1..f5f0c9377752 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -6,6 +6,7 @@ */ #include "dm-core.h" +#include "flt-control.h" #include <linux/module.h> #include <linux/vmalloc.h> @@ -1700,6 +1701,27 @@ static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags) {DM_GET_TARGET_VERSION, 0, get_target_version}, }; + static const struct { + int cmd; + int flags; + ioctl_fn fn; + } _flt_ioctls[] = { + {FLT_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, filter_remove_all}, + {FLT_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, filter_create}, + {FLT_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, filter_remove}, + {FLT_CONTROL_CMD, 0, filter_control}, + }; + + if (cmd >= DM_FILTER_CMD) { + cmd -= DM_FILTER_CMD; + + if (unlikely(cmd >= ARRAY_SIZE(_flt_ioctls))) + return NULL; + + *ioctl_flags = _flt_ioctls[cmd].flags; + return _flt_ioctls[cmd].fn; + } + if (unlikely(cmd >= ARRAY_SIZE(_ioctls))) return NULL; diff --git a/drivers/md/flt-ctl.c b/drivers/md/flt-ctl.c new file mode 100644 index 000000000000..aadf04be1438 --- /dev/null +++ b/drivers/md/flt-ctl.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/dm-ioctl.h> + +#include "flt-ctl.h" + +int filter_remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size) +{ + return 0; +}; +int filter_create(struct file *filp, struct dm_ioctl *param, size_t param_size) +{ + return 0; +}; +int filter_remove(struct file *filp, struct dm_ioctl *param, size_t param_size) +{ + return 0; +}; +int filter_control(struct file *filp, struct dm_ioctl *param, size_t param_size) +{ + return 0; +}; + diff --git a/drivers/md/flt-ctl.h b/drivers/md/flt-ctl.h new file mode 100644 index 000000000000..61a80184abae --- /dev/null +++ b/drivers/md/flt-ctl.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: LGPL-2.0+ WITH Linux-syscall-note */ +#ifndef FLT_CTL_H +#define FLT_CTL_H + +int filter_remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size); +int filter_create(struct file *filp, struct dm_ioctl *param, size_t param_size); +int filter_remove(struct file *filp, struct dm_ioctl *param, size_t param_size); +int filter_control(struct file *filp, struct dm_ioctl *param, size_t param_size); + +#endif diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h index e942e7d7c594..012e16761ba9 100644 --- a/include/uapi/linux/dm-ioctl.h +++ b/include/uapi/linux/dm-ioctl.h @@ -16,6 +16,7 @@ #define DM_MAX_TYPE_NAME 16 #define DM_NAME_LEN 128 #define DM_UUID_LEN 129 +#define DM_FILTER_CMD 128 /* First filters command */ /* * A traditional ioctl interface for the device mapper. @@ -244,6 +245,14 @@ enum { DM_DEV_SET_GEOMETRY_CMD, DM_DEV_ARM_POLL_CMD, DM_GET_TARGET_VERSION_CMD, + + /* Reserved space for additional DM ioctl */ + + /* Filters commands */ + FLT_REMOVE_ALL_CMD = DM_FILTER_CMD, /* Cleanup all filters */ + FLT_CREATE_CMD, /* Create new filter */ + FLT_REMOVE_CMD, /* Remove filter */ + FLT_CONTROL_CMD, /* Send a filter-specific command */ }; #define DM_IOCTL 0xfd @@ -271,10 +280,15 @@ enum { #define DM_TARGET_MSG _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl) #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) +#define FLT_REMOVE_ALL _IOWR(DM_IOCTL, FLT_REMOVE_ALL_CMD, struct dm_ioctl) +#define FLT_CREATE _IOWR(DM_IOCTL, FLT_CREATE_CMD, struct dm_ioctl) +#define FLT_REMOVE _IOWR(DM_IOCTL, FLT_REMOVE_CMD, struct dm_ioctl) +#define FLT_CONTROL _IOWR(DM_IOCTL, FLT_CONTROL_CMD, struct dm_ioctl) + #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 43 +#define DM_VERSION_MINOR 44 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2020-10-01)" +#define DM_VERSION_EXTRA "-ioctl (2021-03-03)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ -- 2.20.1
