This adds a function API to manipulate partition tables. Basically partition_table_new() and partition_table_read() are factored out from existing code. Apart from that we will have partition_create() to create a new partition and partition_remove() to remove a partition. These functions do basic sanity checks like partition overlap checking, access beyond device cheks and call into not yet existing efi or msdos specific function hooks.
Signed-off-by: Sascha Hauer <[email protected]> --- common/Kconfig | 3 + common/partitions.c | 156 ++++++++++++++++++++++++++++++++++++------- include/partitions.h | 22 ++++++ 3 files changed, 157 insertions(+), 24 deletions(-) diff --git a/common/Kconfig b/common/Kconfig index ddca1e913b..d16c8696da 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -841,6 +841,9 @@ config PARTITION bool prompt "Enable Partitions" +config PARTITION_MANIPULATION + bool + source "common/partitions/Kconfig" config ENV_HANDLING diff --git a/common/partitions.c b/common/partitions.c index abbe31ed11..7bcd0973b8 100644 --- a/common/partitions.c +++ b/common/partitions.c @@ -102,6 +102,133 @@ static struct partition_parser *partition_parser_get_by_filetype(uint8_t *buf) return NULL; } +struct partition_desc *partition_table_new(struct block_device *blk, const char *type) +{ + struct partition_desc *pdesc; + struct partition_parser *parser; + + list_for_each_entry(parser, &partition_parser_list, list) { + if (!strcmp(parser->name, type)) + goto found; + } + + pr_err("Cannot find partition parser \"%s\"\n", type); + + return ERR_PTR(-ENOSYS); + +found: + pdesc = parser->create(blk); + if (IS_ERR(pdesc)) + return ERR_CAST(pdesc); + + pdesc->parser = parser; + + return pdesc; +} + +struct partition_desc *partition_table_read(struct block_device *blk) +{ + struct partition_parser *parser; + struct partition_desc *pdesc = NULL; + uint8_t *buf; + int ret; + + buf = malloc(2 * SECTOR_SIZE); + + ret = block_read(blk, buf, 0, 2); + if (ret != 0) { + dev_err(blk->dev, "Cannot read MBR/partition table: %pe\n", ERR_PTR(ret)); + goto err; + } + + parser = partition_parser_get_by_filetype(buf); + if (!parser) + goto err; + + pdesc = parser->parse(buf, blk); + pdesc->parser = parser; +err: + free(buf); + + return pdesc; +} + +int partition_table_write(struct partition_desc *pdesc) +{ + if (!pdesc->parser->write) + return -ENOSYS; + + return pdesc->parser->write(pdesc); +} + +static bool overlap(uint64_t s1, uint64_t e1, uint64_t s2, uint64_t e2) +{ + if (e1 < s2) + return false; + if (s1 > e2) + return false; + return true; +} + +int partition_create(struct partition_desc *pdesc, const char *name, + const char *fs_type, uint64_t lba_start, uint64_t lba_end) +{ + struct partition *part; + + if (!pdesc->parser->mkpart) + return -ENOSYS; + + if (lba_end < lba_start) { + pr_err("lba_end < lba_start: %llu < %llu\n", lba_end, lba_start); + return -EINVAL; + } + + if (lba_end >= pdesc->blk->num_blocks) { + pr_err("lba_end exceeds device: %llu >= %llu\n", lba_end, pdesc->blk->num_blocks); + return -EINVAL; + } + + list_for_each_entry(part, &pdesc->partitions, list) { + if (overlap(part->first_sec, + part->first_sec + part->size - 1, + lba_start, lba_end)) { + pr_err("new partition %llu-%llu overlaps with partition %s (%llu-%llu)\n", + lba_start, lba_end, part->name, part->first_sec, + part->first_sec + part->size - 1); + return -EINVAL; + } + } + + return pdesc->parser->mkpart(pdesc, name, fs_type, lba_start, lba_end); +} + +int partition_remove(struct partition_desc *pdesc, int num) +{ + struct partition *part; + + if (!pdesc->parser->rmpart) + return -ENOSYS; + + list_for_each_entry(part, &pdesc->partitions, list) { + if (part->num == num) + return pdesc->parser->rmpart(pdesc, part); + } + + pr_err("Partition %d doesn't exist\n", num); + return -ENOENT; +} + +void partition_table_free(struct partition_desc *pdesc) +{ + pdesc->parser->partition_free(pdesc); +} + +void partition_desc_init(struct partition_desc *pd, struct block_device *blk) +{ + pd->blk = blk; + INIT_LIST_HEAD(&pd->partitions); +} + /** * Try to collect partition information on the given block device * @param blk Block device to examine @@ -111,31 +238,14 @@ static struct partition_parser *partition_parser_get_by_filetype(uint8_t *buf) */ int parse_partition_table(struct block_device *blk) { - struct partition_desc *pdesc = NULL; int i; int rc = 0; - struct partition_parser *parser; struct partition *part; - uint8_t *buf; - - buf = malloc(2 * SECTOR_SIZE); + struct partition_desc *pdesc; - rc = block_read(blk, buf, 0, 2); - if (rc != 0) { - dev_err(blk->dev, "Cannot read MBR/partition table: %pe\n", ERR_PTR(rc)); - goto on_error; - } - - parser = partition_parser_get_by_filetype(buf); - if (!parser) - goto on_error; - - pdesc = parser->parse(buf, blk); + pdesc = partition_table_read(blk); if (!pdesc) - goto on_error; - - if (list_empty(&pdesc->partitions)) - goto on_error; + return 0; /* at least one partition description found */ list_for_each_entry(part, &pdesc->partitions, list) { @@ -148,10 +258,8 @@ int parse_partition_table(struct block_device *blk) rc = 0; } -on_error: - free(buf); - if (pdesc) - parser->partition_free(pdesc); + partition_table_free(pdesc); + return rc; } diff --git a/include/partitions.h b/include/partitions.h index ab593109e6..b5379db92a 100644 --- a/include/partitions.h +++ b/include/partitions.h @@ -28,18 +28,40 @@ struct partition { int num; }; +struct partition_parser; + struct partition_desc { struct list_head partitions; + struct partition_parser *parser; + struct block_device *blk; }; struct partition_parser { struct partition_desc *(*parse)(void *buf, struct block_device *blk); void (*partition_free)(struct partition_desc *pd); + struct partition_desc *(*create)(struct block_device *blk); + int (*mkpart)(struct partition_desc *pd, const char *name, const char *fs_type, + uint64_t start, uint64_t end); + int (*rmpart)(struct partition_desc *pd, struct partition *part); + int (*write)(struct partition_desc *pd); + int (*rename)(struct partition *part, const char *name); + int (*setguid)(struct partition *part, guid_t *guid); enum filetype type; struct list_head list; + + const char *name; }; +void partition_desc_init(struct partition_desc *pd, struct block_device *blk); int partition_parser_register(struct partition_parser *p); +struct partition_desc *partition_table_read(struct block_device *blk); +struct partition_desc *partition_table_new(struct block_device *blk, const char *type); +int partition_table_write(struct partition_desc *pdesc); +int partition_create(struct partition_desc *pdesc, const char *name, + const char *fs_type, uint64_t lba_start, uint64_t lba_end); +int partition_remove(struct partition_desc *pdesc, int num); +void partition_table_free(struct partition_desc *pdesc); + #endif /* __PARTITIONS_PARSER_H__ */ -- 2.39.2
