Commit 256dd1bb authored Aug 10, 2012 by Stefan Behrens Committed by Chris Mason Aug 28, 2012

Btrfs: fix that repair code is spuriously executed for transid failures



If verify_parent_transid() fails for all mirrors, the current code
calls repair_io_failure() anyway which means:
- that the disk block is rewritten without repairing anything and
- that a kernel log message is printed which misleadingly claims
  that a read error was corrected.

This is an example:
parent transid verify failed on 615015833600 wanted 110423 found 110424
parent transid verify failed on 615015833600 wanted 110423 found 110424
btrfs read error corrected: ino 1 off 615015833600 (dev /dev/...)

It is wrong to ignore the results from verify_parent_transid() and to
call repair_eb_io_failure() when the verification of the transids failed.
This commit fixes the issue.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

parent d280e5be

fs/btrfs/disk-io.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -377,9 +377,13 @@ static int btree_read_extent_buffer_pages(struct btrfs_root *root,
		ret = read_extent_buffer_pages(io_tree, eb, start,
		WAIT_COMPLETE,
		btree_get_extent, mirror_num);
		if (!ret && !verify_parent_transid(io_tree, eb,
		if (!ret) {
		if (!verify_parent_transid(io_tree, eb,
		parent_transid, 0))
		break;
		else
		ret = -EIO;
		}

		/*
		* This buffer's crc is fine, but its contents are corrupted, so

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