Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992821AbXEBGTp (ORCPT ); Wed, 2 May 2007 02:19:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992826AbXEBGTo (ORCPT ); Wed, 2 May 2007 02:19:44 -0400 Received: from mga02.intel.com ([134.134.136.20]:42723 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992821AbXEBGTm (ORCPT ); Wed, 2 May 2007 02:19:42 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.14,477,1170662400"; d="scan'208";a="237751283" From: Dan Williams Subject: [PATCH 10/16] md: satisfy raid5 read requests via raid5_run_ops To: neilb@suse.de, akpm@linux-foundation.org, christopher.leech@intel.com Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org Date: Tue, 01 May 2007 23:19:41 -0700 Message-ID: <20070502061941.7066.92570.stgit@dwillia2-linux.ch.intel.com> In-Reply-To: <20070502060949.7066.357.stgit@dwillia2-linux.ch.intel.com> References: <20070502060949.7066.357.stgit@dwillia2-linux.ch.intel.com> User-Agent: StGIT/0.12.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4281 Lines: 117 Use raid5_run_ops to carry out the memory copies for a raid5 read request. Changelog: * cleanup to_read and to_fill accounting * do not fail reads that have reached the cache Signed-off-by: Dan Williams --- drivers/md/raid5.c | 61 ++++++++++++++++++++++++++-------------------------- 1 files changed, 30 insertions(+), 31 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index f8a4522..6bde174 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1998,7 +1998,7 @@ static void handle_stripe5(struct stripe_head *sh) int i; int syncing, expanding, expanded; int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; - int compute=0, req_compute=0, non_overwrite=0; + int to_fill=0, compute=0, req_compute=0, non_overwrite=0; int failed_num=0; struct r5dev *dev; unsigned long pending=0; @@ -2022,37 +2022,29 @@ static void handle_stripe5(struct stripe_head *sh) dev = &sh->dev[i]; clear_bit(R5_Insync, &dev->flags); - PRINTK("check %d: state 0x%lx read %p write %p written %p\n", - i, dev->flags, dev->toread, dev->towrite, dev->written); - /* maybe we can reply to a read */ - if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) { - struct bio *rbi, *rbi2; - PRINTK("Return read for disc %d\n", i); - spin_lock_irq(&conf->device_lock); - rbi = dev->toread; - dev->toread = NULL; - if (test_and_clear_bit(R5_Overlap, &dev->flags)) - wake_up(&conf->wait_for_overlap); - spin_unlock_irq(&conf->device_lock); - while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { - copy_data(0, rbi, dev->page, dev->sector); - rbi2 = r5_next_bio(rbi, dev->sector); - spin_lock_irq(&conf->device_lock); - if (--rbi->bi_phys_segments == 0) { - rbi->bi_next = return_bi; - return_bi = rbi; - } - spin_unlock_irq(&conf->device_lock); - rbi = rbi2; - } - } + PRINTK("check %d: state 0x%lx toread %p read %p write %p written %p\n", + i, dev->flags, dev->toread, dev->read, dev->towrite, dev->written); + + /* maybe we can request a biofill operation + * + * new wantfill requests are only permitted while + * STRIPE_OP_BIOFILL is clear + */ + if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread && + !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending)) + set_bit(R5_Wantfill, &dev->flags); /* now count some things */ if (test_bit(R5_LOCKED, &dev->flags)) locked++; if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++; + + if (test_bit(R5_Wantfill, &dev->flags)) + to_fill++; + else if (dev->toread) + to_read++; + if (test_bit(R5_Wantcompute, &dev->flags)) BUG_ON(++compute > 1); - if (dev->toread) to_read++; if (dev->towrite) { to_write++; if (!test_bit(R5_OVERWRITE, &dev->flags)) @@ -2073,9 +2065,13 @@ static void handle_stripe5(struct stripe_head *sh) set_bit(R5_Insync, &dev->flags); } rcu_read_unlock(); + + if (to_fill && !test_and_set_bit(STRIPE_OP_BIOFILL, &sh->ops.pending)) + sh->ops.count++; + PRINTK("locked=%d uptodate=%d to_read=%d" - " to_write=%d failed=%d failed_num=%d\n", - locked, uptodate, to_read, to_write, failed, failed_num); + " to_write=%d to_fill=%d failed=%d failed_num=%d\n", + locked, uptodate, to_read, to_write, to_fill, failed, failed_num); /* check if the array has lost two devices and, if so, some requests might * need to be failed */ @@ -2127,9 +2123,12 @@ static void handle_stripe5(struct stripe_head *sh) bi = bi2; } - /* fail any reads if this device is non-operational */ - if (!test_bit(R5_Insync, &sh->dev[i].flags) || - test_bit(R5_ReadError, &sh->dev[i].flags)) { + /* fail any reads if this device is non-operational and + * the data has not reached the cache yet. + */ + if (!test_bit(R5_Wantfill, &sh->dev[i].flags) && + (!test_bit(R5_Insync, &sh->dev[i].flags) || + test_bit(R5_ReadError, &sh->dev[i].flags))) { bi = sh->dev[i].toread; sh->dev[i].toread = NULL; if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/