Edit File: dm-ioctl.h
/* * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited. * Copyright (C) 2004 - 2009 Red Hat, Inc. All rights reserved. * * This file is released under the LGPL. */ #ifndef _LINUX_DM_IOCTL_V4_H #define _LINUX_DM_IOCTL_V4_H #include <linux/types.h> #define DM_DIR "mapper" /* Slashes not supported */ #define DM_CONTROL_NODE "control" #define DM_MAX_TYPE_NAME 16 #define DM_NAME_LEN 128 #define DM_UUID_LEN 129 /* * A traditional ioctl interface for the device mapper. * * Each device can have two tables associated with it, an * 'active' table which is the one currently used by io passing * through the device, and an 'inactive' one which is a table * that is being prepared as a replacement for the 'active' one. * * DM_VERSION: * Just get the version information for the ioctl interface. * * DM_REMOVE_ALL: * Remove all dm devices, destroy all tables. Only really used * for debug. * * DM_LIST_DEVICES: * Get a list of all the dm device names. * * DM_DEV_CREATE: * Create a new device, neither the 'active' or 'inactive' table * slots will be filled. The device will be in suspended state * after creation, however any io to the device will get errored * since it will be out-of-bounds. * * DM_DEV_REMOVE: * Remove a device, destroy any tables. * * DM_DEV_RENAME: * Rename a device or set its uuid if none was previously supplied. * * DM_SUSPEND: * This performs both suspend and resume, depending which flag is * passed in. * Suspend: This command will not return until all pending io to * the device has completed. Further io will be deferred until * the device is resumed. * Resume: It is no longer an error to issue this command on an * unsuspended device. If a table is present in the 'inactive' * slot, it will be moved to the active slot, then the old table * from the active slot will be _destroyed_. Finally the device * is resumed. * * DM_DEV_STATUS: * Retrieves the status for the table in the 'active' slot. * * DM_DEV_WAIT: * Wait for a significant event to occur to the device. This * could either be caused by an event triggered by one of the * targets of the table in the 'active' slot, or a table change. * * DM_TABLE_LOAD: * Load a table into the 'inactive' slot for the device. The * device does _not_ need to be suspended prior to this command. * * DM_TABLE_CLEAR: * Destroy any table in the 'inactive' slot (ie. abort). * * DM_TABLE_DEPS: * Return a set of device dependencies for the 'active' table. * * DM_TABLE_STATUS: * Return the targets status for the 'active' table. * * DM_TARGET_MSG: * Pass a message string to the target at a specific offset of a device. * * DM_DEV_SET_GEOMETRY: * Set the geometry of a device by passing in a string in this format: * * "cylinders heads sectors_per_track start_sector" * * Beware that CHS geometry is nearly obsolete and only provided * for compatibility with dm devices that can be booted by a PC * BIOS. See struct hd_geometry for range limits. Also note that * the geometry is erased if the device size changes. */ /* * All ioctl arguments consist of a single chunk of memory, with * this structure at the start. If a uuid is specified any * lookup (eg. for a DM_INFO) will be done on that, *not* the * name. */ struct dm_ioctl { /* * The version number is made up of three parts: * major - no backward or forward compatibility, * minor - only backwards compatible, * patch - both backwards and forwards compatible. * * All clients of the ioctl interface should fill in the * version number of the interface that they were * compiled with. * * All recognised ioctl commands (ie. those that don't * return -ENOTTY) fill out this field, even if the * command failed. */ __u32 version[3]; /* in/out */ __u32 data_size; /* total size of data passed in * including this struct */ __u32 data_start; /* offset to start of data * relative to start of this struct */ __u32 target_count; /* in/out */ __s32 open_count; /* out */ __u32 flags; /* in/out */ /* * event_nr holds either the event number (input and output) or the * udev cookie value (input only). * The DM_DEV_WAIT ioctl takes an event number as input. * The DM_SUSPEND, DM_DEV_REMOVE and DM_DEV_RENAME ioctls * use the field as a cookie to return in the DM_COOKIE * variable with the uevents they issue. * For output, the ioctls return the event number, not the cookie. */ __u32 event_nr; /* in/out */ __u32 padding; __u64 dev; /* in/out */ char name[DM_NAME_LEN]; /* device name */ char uuid[DM_UUID_LEN]; /* unique identifier for * the block device */ char data[7]; /* padding or data */ }; /* * Used to specify tables. These structures appear after the * dm_ioctl. */ struct dm_target_spec { __u64 sector_start; __u64 length; __s32 status; /* used when reading from kernel only */ /* * Location of the next dm_target_spec. * - When specifying targets on a DM_TABLE_LOAD command, this value is * the number of bytes from the start of the "current" dm_target_spec * to the start of the "next" dm_target_spec. * - When retrieving targets on a DM_TABLE_STATUS command, this value * is the number of bytes from the start of the first dm_target_spec * (that follows the dm_ioctl struct) to the start of the "next" * dm_target_spec. */ __u32 next; char target_type[DM_MAX_TYPE_NAME]; /* * Parameter string starts immediately after this object. * Be careful to add padding after string to ensure correct * alignment of subsequent dm_target_spec. */ }; /* * Used to retrieve the target dependencies. */ struct dm_target_deps { __u32 count; /* Array size */ __u32 padding; /* unused */ __u64 dev[0]; /* out */ }; /* * Used to get a list of all dm devices. */ struct dm_name_list { __u64 dev; __u32 next; /* offset to the next record from the _start_ of this */ char name[0]; }; /* * Used to retrieve the target versions */ struct dm_target_versions { __u32 next; __u32 version[3]; char name[0]; }; /* * Used to pass message to a target */ struct dm_target_msg { __u64 sector; /* Device sector */ char message[0]; }; /* * If you change this make sure you make the corresponding change * to dm-ioctl.c:lookup_ioctl() */ enum { /* Top level cmds */ DM_VERSION_CMD = 0, DM_REMOVE_ALL_CMD, DM_LIST_DEVICES_CMD, /* device level cmds */ DM_DEV_CREATE_CMD, DM_DEV_REMOVE_CMD, DM_DEV_RENAME_CMD, DM_DEV_SUSPEND_CMD, DM_DEV_STATUS_CMD, DM_DEV_WAIT_CMD, /* Table level cmds */ DM_TABLE_LOAD_CMD, DM_TABLE_CLEAR_CMD, DM_TABLE_DEPS_CMD, DM_TABLE_STATUS_CMD, /* Added later */ DM_LIST_VERSIONS_CMD, DM_TARGET_MSG_CMD, DM_DEV_SET_GEOMETRY_CMD, DM_DEV_ARM_POLL_CMD, }; #define DM_IOCTL 0xfd #define DM_VERSION _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl) #define DM_REMOVE_ALL _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl) #define DM_LIST_DEVICES _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl) #define DM_DEV_CREATE _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl) #define DM_DEV_REMOVE _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl) #define DM_DEV_RENAME _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl) #define DM_DEV_SUSPEND _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl) #define DM_DEV_STATUS _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl) #define DM_DEV_WAIT _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl) #define DM_DEV_ARM_POLL _IOWR(DM_IOCTL, DM_DEV_ARM_POLL_CMD, struct dm_ioctl) #define DM_TABLE_LOAD _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl) #define DM_TABLE_CLEAR _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl) #define DM_TABLE_DEPS _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl) #define DM_TABLE_STATUS _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl) #define DM_LIST_VERSIONS _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, struct dm_ioctl) #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 DM_VERSION_MAJOR 4 #define DM_VERSION_MINOR 37 #define DM_VERSION_PATCHLEVEL 1 #define DM_VERSION_EXTRA "-ioctl (2018-04-03)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ #define DM_SUSPEND_FLAG (1 << 1) /* In/Out */ #define DM_PERSISTENT_DEV_FLAG (1 << 3) /* In */ /* * Flag passed into ioctl STATUS command to get table information * rather than current status. */ #define DM_STATUS_TABLE_FLAG (1 << 4) /* In */ /* * Flags that indicate whether a table is present in either of * the two table slots that a device has. */ #define DM_ACTIVE_PRESENT_FLAG (1 << 5) /* Out */ #define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */ /* * Indicates that the buffer passed in wasn't big enough for the * results. */ #define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */ /* * This flag is now ignored. */ #define DM_SKIP_BDGET_FLAG (1 << 9) /* In */ /* * Set this to avoid attempting to freeze any filesystem when suspending. */ #define DM_SKIP_LOCKFS_FLAG (1 << 10) /* In */ /* * Set this to suspend without flushing queued ios. * Also disables flushing uncommitted changes in the thin target before * generating statistics for DM_TABLE_STATUS and DM_DEV_WAIT. */ #define DM_NOFLUSH_FLAG (1 << 11) /* In */ /* * If set, any table information returned will relate to the inactive * table instead of the live one. Always check DM_INACTIVE_PRESENT_FLAG * is set before using the data returned. */ #define DM_QUERY_INACTIVE_TABLE_FLAG (1 << 12) /* In */ /* * If set, a uevent was generated for which the caller may need to wait. */ #define DM_UEVENT_GENERATED_FLAG (1 << 13) /* Out */ /* * If set, rename changes the uuid not the name. Only permitted * if no uuid was previously supplied: an existing uuid cannot be changed. */ #define DM_UUID_FLAG (1 << 14) /* In */ /* * If set, all buffers are wiped after use. Use when sending * or requesting sensitive data such as an encryption key. */ #define DM_SECURE_DATA_FLAG (1 << 15) /* In */ /* * If set, a message generated output data. */ #define DM_DATA_OUT_FLAG (1 << 16) /* Out */ /* * If set with DM_DEV_REMOVE or DM_REMOVE_ALL this indicates that if * the device cannot be removed immediately because it is still in use * it should instead be scheduled for removal when it gets closed. * * On return from DM_DEV_REMOVE, DM_DEV_STATUS or other ioctls, this * flag indicates that the device is scheduled to be removed when it * gets closed. */ #define DM_DEFERRED_REMOVE (1 << 17) /* In/Out */ /* * If set, the device is suspended internally. */ #define DM_INTERNAL_SUSPEND_FLAG (1 << 18) /* Out */ #endif /* _LINUX_DM_IOCTL_H */