From: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
Introduce a internal helper, write_full_stripe() to calculate P/Q and
write the whole full stripe.
This is useful to recover RAID56 stripes.
Signed-off-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
---
scrub.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)
diff --git a/scrub.c b/scrub.c
index fb14487..cc285d4 100644
--- a/scrub.c
+++ b/scrub.c
@@ -869,3 +869,47 @@ static int recover_from_parities(struct btrfs_fs_info *fs_info,
free(ptrs);
return ret;
}
+
+/*
+ * Helper to write a full stripe to disk
+ * P/Q will be re-calculated.
+ */
+static int write_full_stripe(struct scrub_full_stripe *fstripe)
+{
+ void **ptrs;
+ int nr_stripes = fstripe->nr_stripes;
+ int stripe_len = BTRFS_STRIPE_LEN;
+ int i;
+ int ret = 0;
+
+ ptrs = malloc(sizeof(void *) * fstripe->nr_stripes);
+ if (!ptrs)
+ return -ENOMEM;
+
+ for (i = 0; i < fstripe->nr_stripes; i++)
+ ptrs[i] = fstripe->stripes[i].data;
+
+ if (fstripe->bg_type & BTRFS_BLOCK_GROUP_RAID6) {
+ raid6_gen_syndrome(nr_stripes, stripe_len, ptrs);
+ } else {
+ ret = raid5_gen_result(nr_stripes, stripe_len, nr_stripes - 1,
+ ptrs);
+ if (ret < 0)
+ goto out;
+ }
+
+ for (i = 0; i < fstripe->nr_stripes; i++) {
+ struct scrub_stripe *stripe = &fstripe->stripes[i];
+
+ ret = pwrite(stripe->fd, stripe->data, fstripe->stripe_len,
+ stripe->physical);
+ if (ret != fstripe->stripe_len) {
+ ret = -EIO;
+ goto out;
+ }
+ }
+out:
+ free(ptrs);
+ return ret;
+
+}
--
2.9.4
--
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