Provide the most rudimentary commands needed to inspect and activate volume groups (VGs) and logical volumes (LVs).
Signed-off-by: Tobias Waldekranz <[email protected]> --- commands/Kconfig | 11 ++ commands/Makefile | 1 + commands/lvm.c | 264 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 276 insertions(+) create mode 100644 commands/lvm.c diff --git a/commands/Kconfig b/commands/Kconfig index 08fe544ee1..d7e3bab3f9 100644 --- a/commands/Kconfig +++ b/commands/Kconfig @@ -808,6 +808,17 @@ config CMD_VERITYSETUP commands: open <data-dev> <name> <hash-dev> <root-hash> +config CMD_LVM + tristate + depends on DM_LVM + prompt "lvm" + help + lvm - inspect and activate LVM2 logical volumes + + commands: + pvs / vgs / lvs + activate <vg>/<lv> [<name>] + # end Partition commands endmenu diff --git a/commands/Makefile b/commands/Makefile index 7f0c68a5e5..7dae582225 100644 --- a/commands/Makefile +++ b/commands/Makefile @@ -172,6 +172,7 @@ obj-$(CONFIG_CMD_EFI_HANDLE_DUMP) += efi_handle_dump.o obj-$(CONFIG_CMD_HOST) += host.o obj-$(CONFIG_CMD_DMSETUP) += dmsetup.o obj-$(CONFIG_CMD_VERITYSETUP) += veritysetup.o +obj-$(CONFIG_CMD_LVM) += lvm.o obj-$(CONFIG_CMD_SCONFIG) += sconfig.o obj-$(CONFIG_CMD_RKSECURE) += rksecure.o UBSAN_SANITIZE_ubsan.o := y diff --git a/commands/lvm.c b/commands/lvm.c new file mode 100644 index 0000000000..9ae9e091c1 --- /dev/null +++ b/commands/lvm.c @@ -0,0 +1,264 @@ +// SPDX-License-Identifier: GPL-2.0-only +// SPDX-FileCopyrightText: 2026 Tobias Waldekranz <[email protected]> + +#include <block.h> +#include <command.h> +#include <device-mapper.h> +#include <driver.h> +#include <fs.h> +#include <stdio.h> +#include <xfuncs.h> + +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/sprintf.h> + +#include <lvm.h> + +static int lvm_vg_by_devpath(const char *devpath, struct lvm_vg **vgp) +{ + struct cdev *cdev; + + cdev = cdev_by_name(devpath_to_name(devpath)); + if (!cdev) + return -ENODEV; + + return lvm_vg_alloc_by_cdev(cdev, vgp); +} + +static int lvm_vg_by_spec(const char *spec, struct lvm_vg **vgp) +{ + int err; + + err = lvm_vg_by_devpath(spec, vgp); + switch (err) { + case 0: + return 0; + case -ENODEV: + err = lvm_vg_alloc_by_name(spec, vgp); + if (err) + printf("Found no volume group named \"%s\"\n", spec); + + return err; + } + + printf("No volume group found on \"%s\"\n", spec); + return err; +} + +/* Total size of a VG, in sectors, i.e. the sum of the extents of all + * its physical volumes. + */ +static blkcnt_t lvm_vg_size(struct lvm_vg *vg) +{ + blkcnt_t sectors = 0; + size_t i; + + for (i = 0; i < vg->num_pvs; i++) + sectors += vg->pvs[i]->pe_count * vg->pe_size; + + return sectors; +} + +/* LVM UUIDs are conventionally displayed in 6-4-4-4-4-4-6 groups. */ +#define LVM_UUID_STR_LEN (LVM_UUID_LEN + 6) + +static const char *lvm_uuid_str(char *buf, const char *uuid) +{ + static const int grp[] = { 6, 4, 4, 4, 4, 4, 6 }; + char *out = buf; + size_t g; + + for (g = 0; g < ARRAY_SIZE(grp); g++) { + if (g) + *out++ = '-'; + memcpy(out, uuid, grp[g]); + out += grp[g]; + uuid += grp[g]; + } + *out = '\0'; + return buf; +} + +static void lvm_info_vg(struct lvm_vg *vg) +{ + char uuid[LVM_UUID_STR_LEN + 1]; + char esz[32], vsz[32]; + struct lvm_pv *pv; + struct lvm_lv *lv; + struct cdev *cdev; + size_t i; + + strcpy(vsz, size_human_readable(lvm_vg_size(vg) << SECTOR_SHIFT)); + strcpy(esz, size_human_readable(vg->pe_size << SECTOR_SHIFT)); + + printf("VG \"%s\":\n" + " UUID: %s\n" + " SeqNum: %llu\n" + " Size: %s (%s extents)\n" + " #PV: %zu\n" + " #LV: %zu\n", + vg->name, lvm_uuid_str(uuid, vg->uuid), vg->seqno, vsz, esz, + vg->num_pvs, vg->num_lvs); + + for (i = 0; i < vg->num_pvs; i++) { + pv = vg->pvs[i]; + cdev = lvm_pv_cdev(pv); + + printf(" PV %s:\n" + " UUID: %s\n" + " Size: %s\n", + cdev ? cdev_name(cdev) : "[missing]", + lvm_uuid_str(uuid, pv->uuid), + size_human_readable((u64)pv->dev_size << SECTOR_SHIFT)); + } + + for (i = 0; i < vg->num_lvs; i++) { + lv = vg->lvs[i]; + + printf(" LV \"%s\":\n" + " UUID: %s\n" + " Type: %s\n" + " Size: %s\n", + lv->name, lvm_uuid_str(uuid, lv->uuid), + lv->type == LVM_LV_LINEAR ? "linear" : "unknown", + size_human_readable((u64)lv->size << SECTOR_SHIFT)); + } +} + +static void lvm_info_all(void) +{ + struct lvm_vg_iter *iter; + struct lvm_vg *vg; + int i = 0; + + iter = lvm_vg_iter_new(); + while ((vg = lvm_vg_iter_next(iter))) { + if (i++) + putchar('\n'); + + lvm_info_vg(vg); + lvm_vg_free(vg); + } + + lvm_vg_iter_free(iter); +} + +static int lvm_info(int argc, char *argv[]) +{ + struct lvm_vg *vg = NULL; + + if (argc > 1) + return COMMAND_ERROR_USAGE; + + if (argc == 0) { + lvm_info_all(); + return COMMAND_SUCCESS; + } + + if (lvm_vg_by_spec(argv[0], &vg)) + return COMMAND_ERROR; + + lvm_info_vg(vg); + lvm_vg_free(vg); + return COMMAND_SUCCESS; +} + +static int lvm_activate_lv(struct lvm_lv *lv, const char *name) +{ + char *defname, *table; + struct dm_device *dm; + + table = lvm_lv_dm_ctable(lv); + if (IS_ERR(table)) { + printf("Cannot map %s/%s: %pe\n", lv->vg->name, lv->name, table); + return PTR_ERR(table); + } + + defname = name ? NULL : xasprintf("%s-%s", lv->vg->name, lv->name); + + dm = dm_create(name ? : defname, table); + free(table); + if (IS_ERR(dm)) + printf("Failed to create %s: %pe\n", name ? : defname, dm); + else + printf("Created %s\n", name ? : defname); + + free(defname); + return IS_ERR(dm) ? PTR_ERR(dm) : 0; +} + +static int lvm_activate(int argc, char *argv[]) +{ + struct lvm_vg *vg = NULL; + struct lvm_lv *lv; + int err; + + if (argc < 2 || argc > 3) + return COMMAND_ERROR_USAGE; + + if (lvm_vg_by_spec(argv[0], &vg)) + return COMMAND_ERROR; + + lv = lvm_vg_lv_by_name(vg, argv[1]); + if (!lv) { + printf("Logical volume \"%s/%s\" not found\n", vg->name, argv[1]); + err = -ENOENT; + goto out_free; + } + + err = lvm_activate_lv(lv, (argc == 3) ? argv[2] : NULL); + +out_free: + lvm_vg_free(vg); + return err ? COMMAND_ERROR : COMMAND_SUCCESS; +} + +static int do_lvm(int argc, char *argv[]) +{ + const char *cmd; + + switch (argc) { + case 1: + cmd = "info"; + argc--; + argv++; + break; + default: + cmd = argv[1]; + argc -= 2; + argv += 2; + break; + } + + if (!strcmp(cmd, "info")) + return lvm_info(argc, argv); + else if (!strcmp(cmd, "activate")) + return lvm_activate(argc, argv); + + printf("Unknown command: %s\n", cmd); + return COMMAND_ERROR_USAGE; +} + +BAREBOX_CMD_HELP_START(lvm) +BAREBOX_CMD_HELP_TEXT("lvm - inspect and activate LVM logical volumes") +BAREBOX_CMD_HELP_TEXT("") +BAREBOX_CMD_HELP_TEXT("Assembles the volume groups described by the LVM physical volumes") +BAREBOX_CMD_HELP_TEXT("found on the available block devices, and activates logical volumes") +BAREBOX_CMD_HELP_TEXT("as device mapper devices.") +BAREBOX_CMD_HELP_TEXT("") +BAREBOX_CMD_HELP_TEXT("A <vg> may be given either as a volume group name or as the path to") +BAREBOX_CMD_HELP_TEXT("a block device holding one of its physical volumes.") +BAREBOX_CMD_HELP_TEXT("") +BAREBOX_CMD_HELP_TEXT("commands:") +BAREBOX_CMD_HELP_OPT("info [<vg>]", "Show volume groups (all if <vg> is omitted)") +BAREBOX_CMD_HELP_OPT("activate <vg> <lv> [<name>]", "Create a dm device for an LV") +BAREBOX_CMD_HELP_END + +BAREBOX_CMD_START(lvm) + .cmd = do_lvm, + BAREBOX_CMD_DESC("inspect and activate LVM logical volumes") + BAREBOX_CMD_OPTS("<command> [args...]") + BAREBOX_CMD_GROUP(CMD_GRP_PART) + BAREBOX_CMD_HELP(cmd_lvm_help) +BAREBOX_CMD_END -- 2.43.0
