From 93b3dbce6456a79c545b45e86ccc2244e923cc99 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 27 Jul 2011 11:00:36 +1000 Subject: [PATCH] md/raid5: unite fetch_block5 and fetch_block6 Provided that ->failed_num[1] is not a valid device number (which is easily achieved) fetch_block6 provides all the functionality of fetch_block5. So remove the latter and rename the former to simply "fetch_block". Then handle_stripe_fill5 and handle_stripe_fill6 become the same and can similarly be united. Signed-off-by: NeilBrown Reviewed-by: Namhyung Kim --- drivers/md/raid5.c | 107 ++++++++++----------------------------------- 1 file changed, 23 insertions(+), 84 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index a3d7cd96cfb7..a63a679105ca 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2308,91 +2308,20 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh, md_wakeup_thread(conf->mddev->thread); } -/* fetch_block5 - checks the given member device to see if its data needs +/* fetch_block - 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_fill5 to continue + * 0 to tell the loop in handle_stripe_fill to continue */ -static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s, - int disk_idx, int disks) -{ - struct r5dev *dev = &sh->dev[disk_idx]; - struct r5dev *failed_dev = &sh->dev[s->failed_num[0]]; - - /* is the data in this block needed, and can we get it? */ - 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 && failed_dev->toread) || - (s->failed && failed_dev->towrite && - !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) { - /* We would like to get this block, possibly by computing it, - * otherwise read it if the backing disk is insync - */ - if ((s->uptodate == disks - 1) && - (s->failed && disk_idx == s->failed_num[0])) { - 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; - s->req_compute = 1; - /* Careful: from this point on 'uptodate' is in the eye - * of raid_run_ops which services 'compute' operations - * before writes. R5_Wantcompute flags a block that will - * be R5_UPTODATE by the time it is needed for a - * subsequent operation. - */ - s->uptodate++; - return 1; /* uptodate + compute == disks */ - } 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_fill5 - read or compute data to satisfy pending requests. - */ -static void handle_stripe_fill5(struct stripe_head *sh, - struct stripe_head_state *s, 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_block5(sh, s, i, disks)) - break; - set_bit(STRIPE_HANDLE, &sh->state); -} - -/* 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, - int disk_idx, int disks) +static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s, + int disk_idx, int disks) { struct r5dev *dev = &sh->dev[disk_idx]; struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]], &sh->dev[s->failed_num[1]] }; + /* is the data in this block needed, and can we get it? */ if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) && (dev->toread || @@ -2400,7 +2329,9 @@ static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s, s->syncing || s->expanding || (s->failed >= 1 && fdev[0]->toread) || (s->failed >= 2 && fdev[1]->toread) || - (s->failed && s->to_write)) { + (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite && + !test_bit(R5_OVERWRITE, &fdev[0]->flags)) || + (sh->raid_conf->level == 6 && s->failed && s->to_write))) { /* we would like to get this block, possibly by computing it, * otherwise read it if the backing disk is insync */ @@ -2420,6 +2351,12 @@ static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s, sh->ops.target = disk_idx; sh->ops.target2 = -1; /* no 2nd target */ s->req_compute = 1; + /* Careful: from this point on 'uptodate' is in the eye + * of raid_run_ops which services 'compute' operations + * before writes. R5_Wantcompute flags a block that will + * be R5_UPTODATE by the time it is needed for a + * subsequent operation. + */ s->uptodate++; return 1; } else if (s->uptodate == disks-2 && s->failed >= 2) { @@ -2460,11 +2397,11 @@ static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s, } /** - * handle_stripe_fill6 - read or compute data to satisfy pending requests. + * handle_stripe_fill - read or compute data to satisfy pending requests. */ -static void handle_stripe_fill6(struct stripe_head *sh, - struct stripe_head_state *s, - int disks) +static void handle_stripe_fill(struct stripe_head *sh, + struct stripe_head_state *s, + int disks) { int i; @@ -2475,7 +2412,7 @@ static void handle_stripe_fill6(struct stripe_head *sh, if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && !sh->reconstruct_state) for (i = disks; i--; ) - if (fetch_block6(sh, s, i, disks)) + if (fetch_block(sh, s, i, disks)) break; set_bit(STRIPE_HANDLE, &sh->state); } @@ -3122,7 +3059,7 @@ static int handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s) */ if (s->to_read || s->non_overwrite || (s->syncing && (s->uptodate + s->compute < disks)) || s->expanding) - handle_stripe_fill5(sh, s, disks); + handle_stripe_fill(sh, s, disks); /* Now we check to see if any write operations have recently * completed @@ -3313,7 +3250,7 @@ static int handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s) */ if (s->to_read || s->non_overwrite || (s->to_write && s->failed) || (s->syncing && (s->uptodate + s->compute < disks)) || s->expanding) - handle_stripe_fill6(sh, s, disks); + handle_stripe_fill(sh, s, disks); /* Now we check to see if any write operations have recently * completed @@ -3397,6 +3334,8 @@ static void handle_stripe(struct stripe_head *sh) s.syncing = test_bit(STRIPE_SYNCING, &sh->state); s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state); s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state); + s.failed_num[0] = -1; + s.failed_num[1] = -1; if (conf->level == 6) done = handle_stripe6(sh, &s); -- 2.20.1