diff options
| -rw-r--r-- | drivers/md/raid5.c | 143 |
1 files changed, 93 insertions, 50 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index a1245cf..49da6f7 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2520,61 +2520,104 @@ static void handle_stripe_fill5(struct stripe_head *sh, set_bit(STRIPE_HANDLE, &sh->state); } -static void handle_stripe_fill6(struct stripe_head *sh, - struct stripe_head_state *s, struct r6_state *r6s, - int disks) +/* fetch_block6 - checks the given member device to see if its data needs + * to be read or computed to satisfy a request. + * + * Returns 1 when no more member devices need to be checked, otherwise returns + * 0 to tell the loop in handle_stripe_fill6 to continue + */ +static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s, + struct r6_state *r6s, int disk_idx, int disks) { - int i; - for (i = disks; i--; ) { - struct r5dev *dev = &sh->dev[i]; - if (!test_bit(R5_LOCKED, &dev->flags) && - !test_bit(R5_UPTODATE, &dev->flags) && - (dev->toread || (dev->towrite && - !test_bit(R5_OVERWRITE, &dev->flags)) || - s->syncing || s->expanding || - (s->failed >= 1 && - (sh->dev[r6s->failed_num[0]].toread || - s->to_write)) || - (s->failed >= 2 && - (sh->dev[r6s->failed_num[1]].toread || - s->to_write)))) { - /* we would like to get this block, possibly - * by computing it, but we might not be able to + struct r5dev *dev = &sh->dev[disk_idx]; + struct r5dev *fdev[2] = { &sh->dev[r6s->failed_num[0]], + &sh->dev[r6s->failed_num[1]] }; + + if (!test_bit(R5_LOCKED, &dev->flags) && + !test_bit(R5_UPTODATE, &dev->flags) && + (dev->toread || + (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) || + s->syncing || s->expanding || + (s->failed >= 1 && + (fdev[0]->toread || s->to_write)) || + (s->failed >= 2 && + (fdev[1]->toread || s->to_write)))) { + /* we would like to get this block, possibly by computing it, + * otherwise read it if the backing disk is insync + */ + BUG_ON(test_bit(R5_Wantcompute, &dev->flags)); + BUG_ON(test_bit(R5_Wantread, &dev->flags)); + if ((s->uptodate == disks - 1) && + (s->failed && (disk_idx == r6s->failed_num[0] || + disk_idx == r6s->failed_num[1]))) { + /* have disk failed, and we're requested to fetch it; + * do compute it */ - if ((s->uptodate == disks - 1) && - (s->failed && (i == r6s->failed_num[0] || - i == r6s->failed_num[1]))) { - pr_debug("Computing stripe %llu block %d\n", - (unsigned long long)sh->sector, i); - compute_block_1(sh, i, 0); - s->uptodate++; - } else if ( s->uptodate == disks-2 && s->failed >= 2 ) { - /* Computing 2-failure is *very* expensive; only - * do it if failed >= 2 - */ - int other; - for (other = disks; other--; ) { - if (other == i) - continue; - if (!test_bit(R5_UPTODATE, - &sh->dev[other].flags)) - break; - } - BUG_ON(other < 0); - pr_debug("Computing stripe %llu blocks %d,%d\n", - (unsigned long long)sh->sector, - i, other); - compute_block_2(sh, i, other); - s->uptodate += 2; - } else if (test_bit(R5_Insync, &dev->flags)) { - set_bit(R5_LOCKED, &dev->flags); - set_bit(R5_Wantread, &dev->flags); - s->locked++; - pr_debug("Reading block %d (sync=%d)\n", - i, s->syncing); + pr_debug("Computing stripe %llu block %d\n", + (unsigned long long)sh->sector, disk_idx); + set_bit(STRIPE_COMPUTE_RUN, &sh->state); + set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); + set_bit(R5_Wantcompute, &dev->flags); + sh->ops.target = disk_idx; + sh->ops.target2 = -1; /* no 2nd target */ + s->req_compute = 1; + s->uptodate++; + return 1; + } else if (s->uptodate == disks-2 && s->failed >= 2) { + /* Computing 2-failure is *very* expensive; only + * do it if failed >= 2 + */ + int other; + for (other = disks; other--; ) { + if (other == disk_idx) + continue; + if (!test_bit(R5_UPTODATE, + &sh->dev[other].flags)) + break; } + BUG_ON(other < 0); + pr_debug("Computing stripe %llu blocks %d,%d\n", + (unsigned long long)sh->sector, + disk_idx, other); + set_bit(STRIPE_COMPUTE_RUN, &sh->state); + set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request); + set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags); + set_bit(R5_Wantcompute, &sh->dev[other].flags); + sh->ops.target = disk_idx; + sh->ops.target2 = other; + s->uptodate += 2; + s->req_compute = 1; + return 1; + } else if (test_bit(R5_Insync, &dev->flags)) { + set_bit(R5_LOCKED, &dev->flags); + set_bit(R5_Wantread, &dev->flags); + s->locked++; + pr_debug("Reading block %d (sync=%d)\n", + disk_idx, s->syncing); } } + + return 0; +} + +/** + * handle_stripe_fill6 - read or compute data to satisfy pending requests. + */ +static void handle_stripe_fill6(struct stripe_head *sh, + struct stripe_head_state *s, struct r6_state *r6s, + int disks) +{ + int i; + + /* look for blocks to read/compute, skip this if a compute + * is already in flight, or if the stripe contents are in the + * midst of changing due to a write + */ + if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && + !sh->reconstruct_state) + for (i = disks; i--; ) + if (fetch_block6(sh, s, r6s, i, disks)) + break; set_bit(STRIPE_HANDLE, &sh->state); } |
