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 <quwen...@cn.fujitsu.com> --- scrub.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/scrub.c b/scrub.c index 3163cacb..94981f2b 100644 --- a/scrub.c +++ b/scrub.c @@ -876,3 +876,47 @@ 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; + +} -- 2.13.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html