From bab55417b10c95e6bff8cea315c315adfa009487 Mon Sep 17 00:00:00 2001 From: Cai Zhiyong Date: Wed, 11 Sep 2013 14:20:09 -0700 Subject: block: support embedded device command line partition Read block device partition table from command line. The partition used for fixed block device (eMMC) embedded device. It is no MBR, save storage space. Bootloader can be easily accessed by absolute address of data on the block device. Users can easily change the partition. This code reference MTD partition, source "drivers/mtd/cmdlinepart.c" About the partition verbose reference "Documentation/block/cmdline-partition.txt" [akpm@linux-foundation.org: fix printk text] [yongjun_wei@trendmicro.com.cn: fix error return code in parse_parts()] Signed-off-by: Cai Zhiyong Cc: Karel Zak Cc: "Wanglin (Albert)" Cc: Marius Groeger Cc: David Woodhouse Cc: Jens Axboe Cc: Brian Norris Cc: Artem Bityutskiy Signed-off-by: Wei Yongjun Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- block/Kconfig | 6 ++ block/Makefile | 1 + block/cmdline-parser.c | 250 +++++++++++++++++++++++++++++++++++++++++++++ block/partitions/Kconfig | 7 ++ block/partitions/Makefile | 1 + block/partitions/check.c | 4 + block/partitions/cmdline.c | 99 ++++++++++++++++++ block/partitions/cmdline.h | 2 + 8 files changed, 370 insertions(+) create mode 100644 block/cmdline-parser.c create mode 100644 block/partitions/cmdline.c create mode 100644 block/partitions/cmdline.h (limited to 'block') diff --git a/block/Kconfig b/block/Kconfig index a7e40a7c821..7f38e40fee0 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -99,6 +99,12 @@ config BLK_DEV_THROTTLING See Documentation/cgroups/blkio-controller.txt for more information. +config CMDLINE_PARSER + bool "Block device command line partition parser" + default n + ---help--- + Parsing command line, get the partitions information. + menu "Partition Types" source "block/partitions/Kconfig" diff --git a/block/Makefile b/block/Makefile index 39b76ba66ff..4fa4be544ec 100644 --- a/block/Makefile +++ b/block/Makefile @@ -18,3 +18,4 @@ obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o +obj-$(CONFIG_CMDLINE_PARSER) += cmdline-parser.o diff --git a/block/cmdline-parser.c b/block/cmdline-parser.c new file mode 100644 index 00000000000..cc2637f8674 --- /dev/null +++ b/block/cmdline-parser.c @@ -0,0 +1,250 @@ +/* + * Parse command line, get partition information + * + * Written by Cai Zhiyong + * + */ +#include +#include +#include + +static int parse_subpart(struct cmdline_subpart **subpart, char *partdef) +{ + int ret = 0; + struct cmdline_subpart *new_subpart; + + *subpart = NULL; + + new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL); + if (!new_subpart) + return -ENOMEM; + + if (*partdef == '-') { + new_subpart->size = (sector_t)(~0ULL); + partdef++; + } else { + new_subpart->size = (sector_t)memparse(partdef, &partdef); + if (new_subpart->size < (sector_t)PAGE_SIZE) { + pr_warn("cmdline partition size is invalid."); + ret = -EINVAL; + goto fail; + } + } + + if (*partdef == '@') { + partdef++; + new_subpart->from = (sector_t)memparse(partdef, &partdef); + } else { + new_subpart->from = (sector_t)(~0ULL); + } + + if (*partdef == '(') { + int length; + char *next = strchr(++partdef, ')'); + + if (!next) { + pr_warn("cmdline partition format is invalid."); + ret = -EINVAL; + goto fail; + } + + length = min_t(int, next - partdef, + sizeof(new_subpart->name) - 1); + strncpy(new_subpart->name, partdef, length); + new_subpart->name[length] = '\0'; + + partdef = ++next; + } else + new_subpart->name[0] = '\0'; + + new_subpart->flags = 0; + + if (!strncmp(partdef, "ro", 2)) { + new_subpart->flags |= PF_RDONLY; + partdef += 2; + } + + if (!strncmp(partdef, "lk", 2)) { + new_subpart->flags |= PF_POWERUP_LOCK; + partdef += 2; + } + + *subpart = new_subpart; + return 0; +fail: + kfree(new_subpart); + return ret; +} + +static void free_subpart(struct cmdline_parts *parts) +{ + struct cmdline_subpart *subpart; + + while (parts->subpart) { + subpart = parts->subpart; + parts->subpart = subpart->next_subpart; + kfree(subpart); + } +} + +static int parse_parts(struct cmdline_parts **parts, const char *bdevdef) +{ + int ret = -EINVAL; + char *next; + int length; + struct cmdline_subpart **next_subpart; + struct cmdline_parts *newparts; + char buf[BDEVNAME_SIZE + 32 + 4]; + + *parts = NULL; + + newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL); + if (!newparts) + return -ENOMEM; + + next = strchr(bdevdef, ':'); + if (!next) { + pr_warn("cmdline partition has no block device."); + goto fail; + } + + length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1); + strncpy(newparts->name, bdevdef, length); + newparts->name[length] = '\0'; + newparts->nr_subparts = 0; + + next_subpart = &newparts->subpart; + + while (next && *(++next)) { + bdevdef = next; + next = strchr(bdevdef, ','); + + length = (!next) ? (sizeof(buf) - 1) : + min_t(int, next - bdevdef, sizeof(buf) - 1); + + strncpy(buf, bdevdef, length); + buf[length] = '\0'; + + ret = parse_subpart(next_subpart, buf); + if (ret) + goto fail; + + newparts->nr_subparts++; + next_subpart = &(*next_subpart)->next_subpart; + } + + if (!newparts->subpart) { + pr_warn("cmdline partition has no valid partition."); + ret = -EINVAL; + goto fail; + } + + *parts = newparts; + + return 0; +fail: + free_subpart(newparts); + kfree(newparts); + return ret; +} + +void cmdline_parts_free(struct cmdline_parts **parts) +{ + struct cmdline_parts *next_parts; + + while (*parts) { + next_parts = (*parts)->next_parts; + free_subpart(*parts); + kfree(*parts); + *parts = next_parts; + } +} + +int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline) +{ + int ret; + char *buf; + char *pbuf; + char *next; + struct cmdline_parts **next_parts; + + *parts = NULL; + + next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + next_parts = parts; + + while (next && *pbuf) { + next = strchr(pbuf, ';'); + if (next) + *next = '\0'; + + ret = parse_parts(next_parts, pbuf); + if (ret) + goto fail; + + if (next) + pbuf = ++next; + + next_parts = &(*next_parts)->next_parts; + } + + if (!*parts) { + pr_warn("cmdline partition has no valid partition."); + ret = -EINVAL; + goto fail; + } + + ret = 0; +done: + kfree(buf); + return ret; + +fail: + cmdline_parts_free(parts); + goto done; +} + +struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts, + const char *bdev) +{ + while (parts && strncmp(bdev, parts->name, sizeof(parts->name))) + parts = parts->next_parts; + return parts; +} + +/* + * add_part() + * 0 success. + * 1 can not add so many partitions. + */ +void cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size, + int slot, + int (*add_part)(int, struct cmdline_subpart *, void *), + void *param) + +{ + sector_t from = 0; + struct cmdline_subpart *subpart; + + for (subpart = parts->subpart; subpart; + subpart = subpart->next_subpart, slot++) { + if (subpart->from == (sector_t)(~0ULL)) + subpart->from = from; + else + from = subpart->from; + + if (from >= disk_size) + break; + + if (subpart->size > (disk_size - from)) + subpart->size = disk_size - from; + + from += subpart->size; + + if (add_part(slot, subpart, param)) + break; + } +} diff --git a/block/partitions/Kconfig b/block/partitions/Kconfig index 4cebb2f0d2f..87a32086535 100644 --- a/block/partitions/Kconfig +++ b/block/partitions/Kconfig @@ -260,3 +260,10 @@ config SYSV68_PARTITION partition table format used by Motorola Delta machines (using sysv68). Otherwise, say N. + +config CMDLINE_PARTITION + bool "Command line partition support" if PARTITION_ADVANCED + select CMDLINE_PARSER + help + Say Y here if you would read the partitions table from bootargs. + The format for the command line is just like mtdparts. diff --git a/block/partitions/Makefile b/block/partitions/Makefile index 2be4d7ba4e3..37a95270503 100644 --- a/block/partitions/Makefile +++ b/block/partitions/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_ACORN_PARTITION) += acorn.o obj-$(CONFIG_AMIGA_PARTITION) += amiga.o obj-$(CONFIG_ATARI_PARTITION) += atari.o obj-$(CONFIG_AIX_PARTITION) += aix.o +obj-$(CONFIG_CMDLINE_PARTITION) += cmdline.o obj-$(CONFIG_MAC_PARTITION) += mac.o obj-$(CONFIG_LDM_PARTITION) += ldm.o obj-$(CONFIG_MSDOS_PARTITION) += msdos.o diff --git a/block/partitions/check.c b/block/partitions/check.c index 19ba207ea7d..9ac1df74f69 100644 --- a/block/partitions/check.c +++ b/block/partitions/check.c @@ -34,6 +34,7 @@ #include "efi.h" #include "karma.h" #include "sysv68.h" +#include "cmdline.h" int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/ @@ -65,6 +66,9 @@ static int (*check_part[])(struct parsed_partitions *) = { adfspart_check_ADFS, #endif +#ifdef CONFIG_CMDLINE_PARTITION + cmdline_partition, +#endif #ifdef CONFIG_EFI_PARTITION efi_partition, /* this must come before msdos */ #endif diff --git a/block/partitions/cmdline.c b/block/partitions/cmdline.c new file mode 100644 index 00000000000..56cf4ffad51 --- /dev/null +++ b/block/partitions/cmdline.c @@ -0,0 +1,99 @@ +/* + * Copyright (C) 2013 HUAWEI + * Author: Cai Zhiyong + * + * Read block device partition table from command line. + * The partition used for fixed block device (eMMC) embedded device. + * It is no MBR, save storage space. Bootloader can be easily accessed + * by absolute address of data on the block device. + * Users can easily change the partition. + * + * The format for the command line is just like mtdparts. + * + * Verbose config please reference "Documentation/block/cmdline-partition.txt" + * + */ + +#include + +#include "check.h" +#include "cmdline.h" + +static char *cmdline; +static struct cmdline_parts *bdev_parts; + +static int add_part(int slot, struct cmdline_subpart *subpart, void *param) +{ + int label_min; + struct partition_meta_info *info; + char tmp[sizeof(info->volname) + 4]; + struct parsed_partitions *state = (struct parsed_partitions *)param; + + if (slot >= state->limit) + return 1; + + put_partition(state, slot, subpart->from >> 9, + subpart->size >> 9); + + info = &state->parts[slot].info; + + label_min = min_t(int, sizeof(info->volname) - 1, + sizeof(subpart->name)); + strncpy(info->volname, subpart->name, label_min); + info->volname[label_min] = '\0'; + + snprintf(tmp, sizeof(tmp), "(%s)", info->volname); + strlcat(state->pp_buf, tmp, PAGE_SIZE); + + state->parts[slot].has_info = true; + + return 0; +} + +static int __init cmdline_parts_setup(char *s) +{ + cmdline = s; + return 1; +} +__setup("blkdevparts=", cmdline_parts_setup); + +/* + * Purpose: allocate cmdline partitions. + * Returns: + * -1 if unable to read the partition table + * 0 if this isn't our partition table + * 1 if successful + */ +int cmdline_partition(struct parsed_partitions *state) +{ + sector_t disk_size; + char bdev[BDEVNAME_SIZE]; + struct cmdline_parts *parts; + + if (cmdline) { + if (bdev_parts) + cmdline_parts_free(&bdev_parts); + + if (cmdline_parts_parse(&bdev_parts, cmdline)) { + cmdline = NULL; + return -1; + } + cmdline = NULL; + } + + if (!bdev_parts) + return 0; + + bdevname(state->bdev, bdev); + parts = cmdline_parts_find(bdev_parts, bdev); + if (!parts) + return 0; + + disk_size = get_capacity(state->bdev->bd_disk) << 9; + + cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state); + + strlcat(state->pp_buf, "\n", PAGE_SIZE); + + return 1; +} diff --git a/block/partitions/cmdline.h b/block/partitions/cmdline.h new file mode 100644 index 00000000000..26e0f8da141 --- /dev/null +++ b/block/partitions/cmdline.h @@ -0,0 +1,2 @@ + +int cmdline_partition(struct parsed_partitions *state); -- cgit v1.2.3-70-g09d2