Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755955AbZKTU1x (ORCPT ); Fri, 20 Nov 2009 15:27:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755481AbZKTU1v (ORCPT ); Fri, 20 Nov 2009 15:27:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:63026 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755473AbZKTU1u (ORCPT ); Fri, 20 Nov 2009 15:27:50 -0500 From: Mike Snitzer To: dm-devel@redhat.com Cc: linux-kernel@vger.kernel.org, Mikulas Patocka Subject: [PATCH v4 04/13] dm exception store: snapshot-merge usage accounting Date: Fri, 20 Nov 2009 15:27:44 -0500 Message-Id: <1258748873-24185-5-git-send-email-snitzer@redhat.com> In-Reply-To: <1258748873-24185-1-git-send-email-snitzer@redhat.com> References: <1258748873-24185-1-git-send-email-snitzer@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2523 Lines: 78 Conditionally adjust snapshot usage accounting if snapshot-merge is in progress. Care is taken to preserve the established kernel<->userspace interface. Signed-off-by: Mike Snitzer Cc: Mikulas Patocka --- drivers/md/dm-snap-persistent.c | 21 ++++++++++++++++++++- 1 files changed, 20 insertions(+), 1 deletions(-) diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c index 1f5752e..3cb609b 100644 --- a/drivers/md/dm-snap-persistent.c +++ b/drivers/md/dm-snap-persistent.c @@ -91,6 +91,7 @@ struct pstore { struct dm_exception_store *store; int version; int valid; + int merging; /* 1 if there is merging going on */ uint32_t exceptions_per_area; /* @@ -506,7 +507,20 @@ static void persistent_usage(struct dm_exception_store *store, { struct pstore *ps = get_info(store); - *sectors_allocated = ps->next_free * store->chunk_size; + /* + * Must maintain the fact that DM reports all metadata chunks + * in 'sectors_allocated' + * - preserves the established kernel<->userspace interface + * - snapshot-merge must account for the first two metadata + * chunks in its 'sectors_allocated' + */ + if (!ps->merging) { + *sectors_allocated = ps->next_free * store->chunk_size; + } else { + *sectors_allocated = + (area_location(ps, ps->current_area) - 1 + + ps->current_committed + 2) * store->chunk_size; + } *total_sectors = get_dev_size(dm_snap_cow(store->snap)->bdev); /* @@ -608,6 +622,8 @@ static int persistent_prepare_exception(struct dm_exception_store *store, chunk_t next_free; sector_t size = get_dev_size(dm_snap_cow(store->snap)->bdev); + ps->merging = 0; + /* Is there enough room ? */ if (size < ((ps->next_free + 1) * store->chunk_size)) return -ENOSPC; @@ -696,6 +712,8 @@ static int persistent_prepare_merge(struct dm_exception_store *store, struct pstore *ps = get_info(store); struct disk_exception de; + ps->merging = 1; + if (!ps->current_committed) { if (!ps->current_area) return 0; @@ -767,6 +785,7 @@ static int persistent_ctr(struct dm_exception_store *store, ps->store = store; ps->valid = 1; + ps->merging = 0; ps->version = SNAPSHOT_DISK_VERSION; ps->area = NULL; ps->zero_area = NULL; -- 1.6.5.2 -- 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/