From 44b6b87610281a4add36a1addd7630095dc8a545 Mon Sep 17 00:00:00 2001 From: Pawel Baldysiak Date: Thu, 28 Sep 2017 14:41:10 +0200 Subject: [PATCH 04/12] imsm: validate multiple ppls during assemble Change validation algorithm to check validity of multiple ppls that are stored in PPL area. If read error occurs during - treat the all PPLs as invalid - there is no guarantee that this one was not latest. If the header CRC is incorrect - assume that there are no further PPLs in PPL area. If whole PPL area was written at least once - there is a possibility that old PPL (with lower generation number) will follow the recent one (with higest generation number). Compare those generation numbers to check which PPL is latest. Signed-off-by: Pawel Baldysiak Signed-off-by: Jes Sorensen --- super-intel.c | 71 +++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 47 insertions(+), 24 deletions(-) diff --git a/super-intel.c b/super-intel.c index 347838e..56dec36 100644 --- a/super-intel.c +++ b/super-intel.c @@ -6106,11 +6106,14 @@ static int validate_ppl_imsm(struct supertype *st, struct mdinfo *info, struct imsm_dev *dev; struct imsm_map *map; __u32 idx; + unsigned int i; + unsigned long long ppl_offset = 0; + unsigned long long prev_gen_num = 0; if (disk->disk.raid_disk < 0) return 0; - if (posix_memalign(&buf, 4096, PPL_HEADER_SIZE)) { + if (posix_memalign(&buf, MAX_SECTOR_SIZE, PPL_HEADER_SIZE)) { pr_err("Failed to allocate PPL header buffer\n"); return -1; } @@ -6123,34 +6126,54 @@ static int validate_ppl_imsm(struct supertype *st, struct mdinfo *info, if (!d || d->index < 0 || is_failed(&d->disk)) goto out; - if (lseek64(d->fd, info->ppl_sector * 512, SEEK_SET) < 0) { - perror("Failed to seek to PPL header location"); - ret = -1; - goto out; - } + ret = 1; + while (ppl_offset < MULTIPLE_PPL_AREA_SIZE_IMSM) { + dprintf("Checking potential PPL at offset: %llu\n", ppl_offset); - if (read(d->fd, buf, PPL_HEADER_SIZE) != PPL_HEADER_SIZE) { - perror("Read PPL header failed"); - ret = -1; - goto out; - } + if (lseek64(d->fd, info->ppl_sector * 512 + ppl_offset, + SEEK_SET) < 0) { + perror("Failed to seek to PPL header location"); + ret = -1; + goto out; + } - ppl_hdr = buf; + if (read(d->fd, buf, PPL_HEADER_SIZE) != PPL_HEADER_SIZE) { + perror("Read PPL header failed"); + ret = -1; + goto out; + } - crc = __le32_to_cpu(ppl_hdr->checksum); - ppl_hdr->checksum = 0; + ppl_hdr = buf; - if (crc != ~crc32c_le(~0, buf, PPL_HEADER_SIZE)) { - dprintf("Wrong PPL header checksum on %s\n", - d->devname); - ret = 1; - } + crc = __le32_to_cpu(ppl_hdr->checksum); + ppl_hdr->checksum = 0; + + if (crc != ~crc32c_le(~0, buf, PPL_HEADER_SIZE)) { + dprintf("Wrong PPL header checksum on %s\n", + d->devname); + goto out; + } + + if (prev_gen_num > __le64_to_cpu(ppl_hdr->generation)) { + /* previous was newest, it was already checked */ + goto out; + } + + if ((__le32_to_cpu(ppl_hdr->signature) != + super->anchor->orig_family_num)) { + dprintf("Wrong PPL header signature on %s\n", + d->devname); + ret = 1; + goto out; + } + + ret = 0; + prev_gen_num = __le64_to_cpu(ppl_hdr->generation); - if (!ret && (__le32_to_cpu(ppl_hdr->signature) != - super->anchor->orig_family_num)) { - dprintf("Wrong PPL header signature on %s\n", - d->devname); - ret = 1; + ppl_offset += PPL_HEADER_SIZE; + for (i = 0; i < __le32_to_cpu(ppl_hdr->entries_count); i++) + ppl_offset += + __le32_to_cpu(ppl_hdr->entries[i].pp_size); } out: -- 2.7.4