[I'll check the corresponding dmsetup changes into CVS next.] Add message-passing ioctl for multipath configuration etc. zero_message is a trivial implementation for easy testing. Probably worth splitting string into words before passing to target (i.e. pass in argc, argv instead of message) or else exporting some version of split_args function. --- diff/drivers/md/dm-ioctl.c 2004-06-01 19:59:25.000000000 +0100 +++ source/drivers/md/dm-ioctl.c 2004-06-08 20:53:24.000000000 +0100 @@ -1097,6 +1097,59 @@ return r; } +/* + * Pass a message to the target that's at the supplied device offset. + */ +static int target_message(struct dm_ioctl *param, size_t param_size) +{ + int r; + struct mapped_device *md; + struct dm_table *table; + struct dm_target *ti; + struct dm_target_msg *tmsg = (void *) param + param->data_start; + + md = find_device(param); + if (!md) + return -ENXIO; + + r = __dev_status(md, param); + if (r) + goto out; + + if (tmsg < (struct dm_target_msg *) (param + 1) || + invalid_str(tmsg->message, (void *) param + param_size)) { + DMWARN("Invalid target message parameters."); + r = -EINVAL; + goto out; + } + + table = dm_get_table(md); + if (!table) + goto out; + + if (tmsg->sector >= dm_table_get_size(table)) { + DMWARN("Target message sector outside device."); + r = -EINVAL; + goto out_table; + } + + ti = dm_table_find_target(table, tmsg->sector); + if (ti->type->message) + r = ti->type->message(ti, tmsg->message); + else { + DMWARN("Target type does not support messages"); + r = -EINVAL; + } + + out_table: + dm_table_put(table); + + out: + param->data_size = 0; + dm_put(md); + return r; +} + /*----------------------------------------------------------------- * Implementation of open/close/ioctl on the special char * device. @@ -1123,7 +1176,9 @@ {DM_TABLE_DEPS_CMD, table_deps}, {DM_TABLE_STATUS_CMD, table_status}, - {DM_LIST_VERSIONS_CMD, list_versions} + {DM_LIST_VERSIONS_CMD, list_versions}, + + {DM_TARGET_MSG_CMD, target_message} }; return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn; --- diff/drivers/md/dm-zero.c 2004-06-07 14:17:05.000000000 +0100 +++ source/drivers/md/dm-zero.c 2004-06-08 20:53:25.000000000 +0100 @@ -64,11 +64,18 @@ return 0; } +static int zero_message(struct dm_target *ti, char *message) +{ + DMERR("dm-zero message received: %s", message); + return 0; +} + static struct target_type zero_target = { .name = "zero", .module = THIS_MODULE, .ctr = zero_ctr, .map = zero_map, + .message = zero_message, }; int __init dm_zero_init(void) --- diff/include/linux/device-mapper.h 2004-06-07 14:24:46.000000000 +0100 +++ source/include/linux/device-mapper.h 2004-06-08 20:53:25.000000000 +0100 @@ -59,6 +59,8 @@ typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, char *result, unsigned int maxlen); +typedef int (*dm_message_fn) (struct dm_target *ti, char *message); + void dm_error(const char *message); /* @@ -84,6 +86,7 @@ dm_suspend_fn suspend; dm_resume_fn resume; dm_status_fn status; + dm_message_fn message; }; struct io_restrictions { --- diff/include/linux/dm-ioctl.h 2004-05-19 22:12:59.000000000 +0100 +++ source/include/linux/dm-ioctl.h 2004-06-08 20:53:25.000000000 +0100 @@ -76,6 +76,9 @@ * * 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. */ /* @@ -179,6 +182,15 @@ }; /* + * Used to pass message to a target + */ +struct dm_target_msg { + uint64_t sector; /* Device sector */ + + char message[0]; +}; + +/* * If you change this make sure you make the corresponding change * to dm-ioctl.c:lookup_ioctl() */ @@ -204,6 +216,7 @@ /* Added later */ DM_LIST_VERSIONS_CMD, + DM_TARGET_MSG_CMD, }; /* @@ -232,6 +245,7 @@ #define DM_TABLE_DEPS_32 _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, ioctl_struct) #define DM_TABLE_STATUS_32 _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, ioctl_struct) #define DM_LIST_VERSIONS_32 _IOWR(DM_IOCTL, DM_LIST_VERSIONS_CMD, ioctl_struct) +#define DM_TARGET_MSG_32 _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, ioctl_struct) #endif #define DM_IOCTL 0xfd @@ -254,10 +268,12 @@ #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_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 1 +#define DM_VERSION_MINOR 2 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2003-12-10)" +#define DM_VERSION_EXTRA "-ioctl (2004-06-08)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */