md/raid5: avoid reading parity blocks for full-stripe write to degraded array
When performing a reconstruct write, we need to read all blocks
that are not being over-written .. except the parity (P and Q) blocks.
The code currently reads these (as they are not being over-written!)
unnecessarily.
Signed-off-by: NeilBrown <neilb@suse.de>
Fixes: ea664c8245f3 ("md/raid5: need_this_block: tidy/fix last condition.")
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 415cac6..85dc0e6 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3282,7 +3282,9 @@
/* reconstruct-write isn't being forced */
return 0;
for (i = 0; i < s->failed; i++) {
- if (!test_bit(R5_UPTODATE, &fdev[i]->flags) &&
+ if (s->failed_num[i] != sh->pd_idx &&
+ s->failed_num[i] != sh->qd_idx &&
+ !test_bit(R5_UPTODATE, &fdev[i]->flags) &&
!test_bit(R5_OVERWRITE, &fdev[i]->flags))
return 1;
}