The PPL signature is used to determine if the stored PPL is valid for a
given array. With IMSM, the PPL signature should match the
orig_family_num field of the superblock. To avoid passing this value
from userspace, it can be read from the IMSM MPB when initializing the
log.
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@xxxxxxxxx>
---
drivers/md/raid5-ppl.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 78 insertions(+), 1 deletion(-)
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index 2132823..2cc4ee9 100644
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -373,6 +373,75 @@ static void __ppl_stripe_write_finished(struct r5l_io_unit *io)
spin_unlock_irqrestore(&log->io_list_lock, flags);
}
+#define IMSM_MPB_SIG "Intel Raid ISM Cfg Sig. "
+#define IMSM_MPB_ORIG_FAMILY_NUM_OFFSET 64
+
+static int ppl_find_signature_imsm(struct mddev *mddev, u32 *signature)
+{
+ struct md_rdev *rdev;
+ char *buf;
+ int ret = 0;
+ u32 orig_family_num = 0;
+ struct page *page;
+ struct mddev *container;
+
+ container = mddev_find_container(mddev);
+ if (!container || strncmp(container->metadata_type, "imsm", 4)) {
+ pr_err("Container metadata type is not imsm\n");
+ return -EINVAL;
+ }
+
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ buf = page_address(page);
+
+ rdev_for_each(rdev, container) {
+ u32 tmp;
+ struct md_rdev *rdev2;
+ bool found = false;
+
+ /* only use rdevs that are both in container and mddev */
+ rdev_for_each(rdev2, mddev)
+ if (rdev2->bdev == rdev->bdev) {
+ found = true;
+ break;
+ }
+
+ if (!found)
+ continue;
+
+ if (!sync_page_io(rdev, 0,
+ queue_logical_block_size(rdev->bdev->bd_queue),
+ page, REQ_OP_READ, 0, true)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ if (strncmp(buf, IMSM_MPB_SIG, strlen(IMSM_MPB_SIG)) != 0) {
+ dbg("imsm mpb signature does not match\n");
+ ret = 1;
+ goto out;
+ }
+
+ tmp = le32_to_cpu(*(u32 *)(buf + IMSM_MPB_ORIG_FAMILY_NUM_OFFSET));
+
+ if (orig_family_num && orig_family_num != tmp) {
+ dbg("orig_family_num is not the same on all disks\n");
+ ret = 1;
+ goto out;
+ }
+
+ orig_family_num = tmp;
+ }
+
+ *signature = orig_family_num;
+out:
+ __free_page(page);
+ return ret;
+}
+
static void ppl_exit_log_child(struct r5l_log *log)
{
clear_bit(JournalPpl, &log->rdev->flags);
@@ -467,9 +536,17 @@ static int __ppl_init_log(struct r5l_log *log, struct r5conf *conf)
return -ENOMEM;
log->private = ppl_conf;
- if (!mddev->external)
+ if (mddev->external) {
+ ret = ppl_find_signature_imsm(mddev, &log->uuid_checksum);
+ if (ret) {
+ pr_err("Failed to read imsm signature\n");
+ ret = -EINVAL;
+ goto err;
+ }
+ } else {
log->uuid_checksum = crc32c_le(~0, mddev->uuid,
sizeof(mddev->uuid));
+ }
if (mddev->bitmap) {
pr_err("PPL is not compatible with bitmap\n");
--
2.10.1
--
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