From patchwork Thu Nov 13 15:15:59 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Yanok X-Patchwork-Id: 8583 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id B7B904751C for ; Fri, 14 Nov 2008 02:18:53 +1100 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: from ocean.emcraft.com (ocean.emcraft.com [213.221.7.182]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 79DE9DDECF for ; Fri, 14 Nov 2008 02:16:55 +1100 (EST) Received: from [172.17.0.9] (helo=localhost.localdomain) by ocean.emcraft.com with esmtp (Exim 4.43) id 1L0dw7-00055K-S7; Thu, 13 Nov 2008 18:16:48 +0300 From: Ilya Yanok To: linux-raid@vger.kernel.org Subject: [PATCH 06/11] md: change handle_stripe_fill6 to work in asynchronous way Date: Thu, 13 Nov 2008 18:15:59 +0300 Message-Id: <1226589364-5619-7-git-send-email-yanok@emcraft.com> X-Mailer: git-send-email 1.5.6.5 In-Reply-To: <1226589364-5619-1-git-send-email-yanok@emcraft.com> References: <1226589364-5619-1-git-send-email-yanok@emcraft.com> X-Spam-Score: -4.3 (----) X-Spam-Report: Spam detection software, running on the system "pacific.emcraft.com", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Change handle_stripe_fill6 to work asynchronously and introduce helper fetch_block6 function for this. Signed-off-by: Yuri Tikhonov Signed-off-by: Ilya Yanok --- drivers/md/raid5.c | 154 ++++++++++++++++++++++++++++++++++++ 1 files changed, 106 insertions(+), 48 deletions(-) [...] Content analysis details: (-4.3 points, 2.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.1 AWL AWL: From: address is in the auto white-list Cc: linuxppc-dev@ozlabs.org, dzu@denx.de, wd@denx.de, Ilya Yanok X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Change handle_stripe_fill6 to work asynchronously and introduce helper fetch_block6 function for this. Signed-off-by: Yuri Tikhonov Signed-off-by: Ilya Yanok --- drivers/md/raid5.c | 154 ++++++++++++++++++++++++++++++++++++---------------- 1 files changed, 106 insertions(+), 48 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 4495df6..2ccecfa 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2226,61 +2226,119 @@ 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 + 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); + if (other == r6s->qd_idx || disk_idx == r6s->qd_idx) { + /* a D+Q failure: compute D from P, + * and recompute Q then */ - 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); + disk_idx = (other == r6s->qd_idx) ? disk_idx : + other; + set_bit(R5_Wantcompute, + &sh->dev[disk_idx].flags); + sh->ops.target = disk_idx; + sh->ops.target2 = -1; /* no 2nd target */ + s->uptodate++; + } else { + /* compute both */ + 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; - } 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); } + 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); }