md/raid: raid5 preserve the writeback action after the parity check (b2176a1d) · Commits · 戴 / test

The problem is that any 'uptodate' vs 'disks' check is not precise in this path. Put a "WARN_ON(!test_bit(R5_UPTODATE, &dev->flags)" on the device that might try to kick off writes and then skip the action. Better to prevent the raid driver from taking unexpected action *and* keep the system alive vs killing the machine with BUG_ON. Note: fixed warning reported by kbuild test robot <lkp@intel.com> Signed-off-by:

Dan Williams <dan.j.williams@intel.com> Signed-off-by:

Nigel Croxon <ncroxon@redhat.com> Signed-off-by:

Song Liu <songliubraving@fb.com>

drivers/md/raid5.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -4191,7 +4191,7 @@ static void handle_parity_checks6(struct r5conf conf, struct stripe_head sh,
		/* now write out any block on a failed drive,
		* or P or Q if they were recomputed
		*/
		BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
		dev = NULL;
		if (s->failed == 2) {
		dev = &sh->dev[s->failed_num[1]];
		s->locked++;
		@@ -4216,6 +4216,14 @@ static void handle_parity_checks6(struct r5conf conf, struct stripe_head sh,
		set_bit(R5_LOCKED, &dev->flags);
		set_bit(R5_Wantwrite, &dev->flags);
		}
		if (WARN_ONCE(dev && !test_bit(R5_UPTODATE, &dev->flags),
		"%s: disk%td not up to date\n",
		mdname(conf->mddev),
		dev - (struct r5dev *) &sh->dev)) {
		clear_bit(R5_LOCKED, &dev->flags);
		clear_bit(R5_Wantwrite, &dev->flags);
		s->locked--;
		}
		clear_bit(STRIPE_DEGRADED, &sh->state);

		set_bit(STRIPE_INSYNC, &sh->state);

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