- if ( failed < 1 )
- failed_num[0] = pd_idx;
- if ( failed < 2 )
- failed_num[1] = (failed_num[0] == qd_idx) ? pd_idx : qd_idx;
-
- failed_needupdate[0] = !test_bit(R5_UPTODATE, &sh->dev[failed_num[0]].flags);
- failed_needupdate[1] = !test_bit(R5_UPTODATE, &sh->dev[failed_num[1]].flags);
-
- PRINTK("sync: failed=%d num=%d,%d fnu=%u%u\n",
- failed, failed_num[0], failed_num[1], failed_needupdate[0], failed_needupdate[1]);
-
-#if 0 /* RAID-6: This code seems to require that CHECK_PARITY destroys the uptodateness of the parity */
- /* should be able to compute the missing block(s) and write to spare */
- if ( failed_needupdate[0] ^ failed_needupdate[1] ) {
- if (uptodate+1 != disks)
- BUG();
- compute_block_1(sh, failed_needupdate[0] ? failed_num[0] : failed_num[1]);
- uptodate++;
- } else if ( failed_needupdate[0] & failed_needupdate[1] ) {
- if (uptodate+2 != disks)
- BUG();
- compute_block_2(sh, failed_num[0], failed_num[1]);
- uptodate += 2;
+ BUG_ON(failed>2);
+ BUG_ON(uptodate < disks);
+ /* Want to check and possibly repair P and Q.
+ * However there could be one 'failed' device, in which
+ * case we can only check one of them, possibly using the
+ * other to generate missing data
+ */
+
+ /* If !tmp_page, we cannot do the calculations,
+ * but as we have set STRIPE_HANDLE, we will soon be called
+ * by stripe_handle with a tmp_page - just wait until then.
+ */
+ if (tmp_page) {
+ if (failed == q_failed) {
+ /* The only possible failed device holds 'Q', so it makes
+ * sense to check P (If anything else were failed, we would
+ * have used P to recreate it).
+ */
+ compute_block_1(sh, pd_idx, 1);
+ if (!page_is_zero(sh->dev[pd_idx].page)) {
+ compute_block_1(sh,pd_idx,0);
+ update_p = 1;
+ }
+ }
+ if (!q_failed && failed < 2) {
+ /* q is not failed, and we didn't use it to generate
+ * anything, so it makes sense to check it
+ */
+ memcpy(page_address(tmp_page),
+ page_address(sh->dev[qd_idx].page),
+ STRIPE_SIZE);
+ compute_parity(sh, UPDATE_PARITY);
+ if (memcmp(page_address(tmp_page),
+ page_address(sh->dev[qd_idx].page),
+ STRIPE_SIZE)!= 0) {
+ clear_bit(STRIPE_INSYNC, &sh->state);
+ update_q = 1;
+ }
+ }
+ if (update_p || update_q) {
+ conf->mddev->resync_mismatches += STRIPE_SECTORS;
+ if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
+ /* don't try to repair!! */
+ update_p = update_q = 0;