diff --git a/block/partitions/cmdline.c b/block/partitions/cmdline.c index e333583ab38c981279401205d2e2151a872287c7..60fb3df9897c205f625181c5ddf7655505e0c5d2 100644 --- a/block/partitions/cmdline.c +++ b/block/partitions/cmdline.c @@ -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);