Btrfs: dev-replace: make sure target is identical to source when raid56 rebuild fails (4759700a) · Commits · 戴 / test

In the last step of scrub_handle_error_block, we try to combine good copies on all possible mirrors, this works fine for raid1 and raid10, but not for raid56 as it's doing parity rebuild. If parity rebuild doesn't get back with correct data which matches its checksum, in case of replace we'd rather write what is stored in the source device than the data calculuated from parity. Signed-off-by:

Liu Bo <bo.li.liu@oracle.com> Signed-off-by:

David Sterba <dsterba@suse.com>

fs/btrfs/scrub.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -1412,8 +1412,17 @@ nodatasum_case:
		if (!page_bad->io_error && !sctx->is_dev_replace)
		continue;

		if (scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
		/*
		* In case of dev replace, if raid56 rebuild process
		* didn't work out correct data, then copy the content
		* in sblock_bad to make sure target device is identical
		* to source device, instead of writing garbage data in
		* sblock_for_recheck array to target device.
		*/
		sblock_other = NULL;
		} else if (page_bad->io_error) {
		/* try to find no-io-error page in mirrors */
		if (page_bad->io_error) {
		for (mirror_index = 0;
		mirror_index < BTRFS_MAX_MIRRORS &&
		sblocks_for_recheck[mirror_index].page_count > 0;

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