Commit a4c9b34d authored Aug 08, 2017 by Brian Foster Committed by Darrick J. Wong Aug 22, 2017

xfs: handle -EFSCORRUPTED during head/tail verification



Torn write and tail overwrite detection both trigger only on
-EFSBADCRC errors. While this is the most likely failure scenario
for each condition, -EFSCORRUPTED is still possible in certain cases
depending on what ends up on disk when a torn write or partial tail
overwrite occurs. For example, an invalid log record h_len can lead
to an -EFSCORRUPTED error when running the log recovery CRC pass.

Therefore, update log head and tail verification to trigger the
associated head/tail fixups in the event of -EFSCORRUPTED errors
along with -EFSBADCRC. Also, -EFSCORRUPTED can currently be returned
from xlog_do_recovery_pass() before rhead_blk is initialized if the
first record encountered happens to be corrupted. This leads to an
incorrect 'first_bad' return value. Initialize rhead_blk earlier in
the function to address that problem as well.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

parent 7f4d01f3

fs/xfs/xfs_log_recover.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -1102,7 +1102,7 @@ xlog_verify_tail(
		first_bad = 0;
		error = xlog_do_recovery_pass(log, head_blk, *tail_blk,
		XLOG_RECOVER_CRCPASS, &first_bad);
		while (error == -EFSBADCRC && first_bad) {
		while ((error == -EFSBADCRC \|\| error == -EFSCORRUPTED) && first_bad) {
		int tail_distance;

		/*
		@@ -1188,7 +1188,7 @@ xlog_verify_head(
		*/
		error = xlog_do_recovery_pass(log, *head_blk, tmp_rhead_blk,
		XLOG_RECOVER_CRCPASS, &first_bad);
		if (error == -EFSBADCRC) {
		if ((error == -EFSBADCRC \|\| error == -EFSCORRUPTED) && first_bad) {
		/*
		* We've hit a potential torn write. Reset the error and warn
		* about it.
		@@ -5257,7 +5257,7 @@ xlog_do_recovery_pass(
		LIST_HEAD (buffer_list);

		ASSERT(head_blk != tail_blk);
		rhead_blk = 0;
		blk_no = rhead_blk = tail_blk;

		for (i = 0; i < XLOG_RHASH_SIZE; i++)
		INIT_HLIST_HEAD(&rhash[i]);
		@@ -5335,7 +5335,6 @@ xlog_do_recovery_pass(
		}

		memset(rhash, 0, sizeof(rhash));
		blk_no = rhead_blk = tail_blk;
		if (tail_blk > head_blk) {
		/*
		* Perform recovery around the end of the physical log.

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