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Commit 645d4095 authored by Wang YanQing's avatar Wang YanQing Committed by Jens Axboe
Browse files

block: add verifier for cmdline partition 

I meet strange filesystem corruption issue recently, the reason
is there are overlaps partitions in cmdline partition argument.

This patch add verifier for cmdline partition, then if there are
overlaps partitions, cmdline_partition will log a warning. We don't
treat overlaps partition as a error:
"
Caizhiyong <caizhiyong@hisilicon.com> said:
Partition overlap was intentionally designed in this cmdline partition.
reference http://lists.infradead.org/pipermail/linux-mtd/2013-August/048092.html


"

Signed-off-by: default avatarWang YanQing <udknight@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0ec6937e

block/partitions/cmdline.c

+57 −0
Original line number Diff line number Diff line
@@ -58,6 +58,62 @@ static int __init cmdline_parts_setup(char *s) 
}

__setup("blkdevparts=", cmdline_parts_setup);



static bool has_overlaps(sector_t from, sector_t size,

			 sector_t from2, sector_t size2)

{

	sector_t end = from + size;

	sector_t end2 = from2 + size2;



	if (from >= from2 && from < end2)

		return true;



	if (end > from2 && end <= end2)

		return true;



	if (from2 >= from && from2 < end)

		return true;



	if (end2 > from && end2 <= end)

		return true;



	return false;

}



static inline void overlaps_warns_header(void)

{

	pr_warn("Overlapping partitions are used in command line partitions.");

	pr_warn("Don't use filesystems on overlapping partitions:");

}



static void cmdline_parts_verifier(int slot, struct parsed_partitions *state)

{

	int i;

	bool header = true;



	for (; slot < state->limit && state->parts[slot].has_info; slot++) {

		for (i = slot+1; i < state->limit && state->parts[i].has_info;

		     i++) {

			if (has_overlaps(state->parts[slot].from,

					 state->parts[slot].size,

					 state->parts[i].from,

					 state->parts[i].size)) {

				if (header) {

					header = false;

					overlaps_warns_header();

				}

				pr_warn("%s[%llu,%llu] overlaps with "

					"%s[%llu,%llu].",

					state->parts[slot].info.volname,

					(u64)state->parts[slot].from << 9,

					(u64)state->parts[slot].size << 9,

					state->parts[i].info.volname,

					(u64)state->parts[i].from << 9,

					(u64)state->parts[i].size << 9);

			}

		}

	}

}



/*

 * Purpose: allocate cmdline partitions.

 * Returns:
@@ -93,6 +149,7 @@ int cmdline_partition(struct parsed_partitions *state) 
	disk_size = get_capacity(state->bdev->bd_disk) << 9;



	cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state);

	cmdline_parts_verifier(1, state);



	strlcat(state->pp_buf, "\n", PAGE_SIZE);