diff options
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5.c | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index bb42551c1a42..a03cf2d889bf 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2902,6 +2902,7 @@ static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s, struct r5dev *dev = &sh->dev[disk_idx]; struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]], &sh->dev[s->failed_num[1]] }; + int i; if (test_bit(R5_LOCKED, &dev->flags) || @@ -2949,16 +2950,37 @@ static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s, * and there is no need to delay that. */ return 0; - if ( - (sh->raid_conf->level <= 5 && fdev[0]->towrite && - !test_bit(R5_OVERWRITE, &fdev[0]->flags)) || - ((sh->raid_conf->level == 6 || - sh->sector >= sh->raid_conf->mddev->recovery_cp) - && - (s->to_write - s->non_overwrite < - sh->raid_conf->raid_disks - sh->raid_conf->max_degraded) - )) - return 1; + + for (i = 0; i < s->failed; i++) { + if (fdev[i]->towrite && + !test_bit(R5_UPTODATE, &fdev[i]->flags) && + !test_bit(R5_OVERWRITE, &fdev[i]->flags)) + /* If we have a partial write to a failed + * device, then we will need to reconstruct + * the content of that device, so all other + * devices must be read. + */ + return 1; + } + + /* If we are forced to do a reconstruct-write, either because + * the current RAID6 implementation only supports that, or + * or because parity cannot be trusted and we are currently + * recovering it, there is extra need to be careful. + * If one of the devices that we would need to read, because + * it is not being overwritten (and maybe not written at all) + * is missing/faulty, then we need to read everything we can. + */ + if (sh->raid_conf->level != 6 && + sh->sector < sh->raid_conf->mddev->recovery_cp) + /* reconstruct-write isn't being forced */ + return 0; + for (i = 0; i < s->failed; i++) { + if (!test_bit(R5_UPTODATE, &fdev[i]->flags) && + !test_bit(R5_OVERWRITE, &fdev[i]->flags)) + return 1; + } + return 0; } |