From patchwork Thu Jan 8 16:13:12 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Milan Broz X-Patchwork-Id: 1383 Received: from hormel.redhat.com (hormel1.redhat.com [209.132.177.33]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n08G9MQw010139 for ; Thu, 8 Jan 2009 08:09:22 -0800 Received: from listman.util.phx.redhat.com (listman.util.phx.redhat.com [10.8.4.110]) by hormel.redhat.com (Postfix) with ESMTP id 65D1F8E0486; Thu, 8 Jan 2009 11:13:01 -0500 (EST) Received: from int-mx2.corp.redhat.com (nat-pool.util.phx.redhat.com [10.8.5.200]) by listman.util.phx.redhat.com (8.13.1/8.13.1) with ESMTP id n08GCx6T021628 for ; Thu, 8 Jan 2009 11:12:59 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n08GCxw8026529 for ; Thu, 8 Jan 2009 11:12:59 -0500 Received: from [10.34.32.183] (mazybook.englab.brq.redhat.com [10.34.32.183]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id n08GCwGA004991 for ; Thu, 8 Jan 2009 11:12:58 -0500 Message-ID: <49662618.80600@redhat.com> Date: Thu, 08 Jan 2009 17:13:12 +0100 From: Milan Broz User-Agent: Thunderbird 2.0.0.19 (X11/20081209) MIME-Version: 1.0 To: device-mapper development X-Enigmail-Version: 0.95.7 X-Scanned-By: MIMEDefang 2.58 on 172.16.27.26 X-loop: dm-devel@redhat.com Subject: [dm-devel] [PATCH 1/4] dm-core: remove current partial barrier implementation X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.5 Precedence: junk Reply-To: device-mapper development List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com Prepare for full barrier implementation - remove the simple one Signed-off-by: Milan Broz --- drivers/md/dm-linear.c | 1 - drivers/md/dm-table.c | 19 ------------------- drivers/md/dm.c | 15 ++++++++++----- drivers/md/dm.h | 1 - include/linux/device-mapper.h | 1 - 5 files changed, 10 insertions(+), 27 deletions(-) -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index bfa107f..79fb53e 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -142,7 +142,6 @@ static struct target_type linear_target = { .status = linear_status, .ioctl = linear_ioctl, .merge = linear_merge, - .features = DM_TARGET_SUPPORTS_BARRIERS, }; int __init dm_linear_init(void) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 2fd66c3..d599143 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -52,8 +52,6 @@ struct dm_table { sector_t *highs; struct dm_target *targets; - unsigned barriers_supported:1; - /* * Indicates the rw permissions for the new logical * device. This should be a combination of FMODE_READ @@ -243,7 +241,6 @@ int dm_table_create(struct dm_table **result, fmode_t mode, INIT_LIST_HEAD(&t->devices); atomic_set(&t->holders, 0); - t->barriers_supported = 1; if (!num_targets) num_targets = KEYS_PER_NODE; @@ -749,10 +746,6 @@ int dm_table_add_target(struct dm_table *t, const char *type, /* FIXME: the plan is to combine high here and then have * the merge fn apply the target level restrictions. */ combine_restrictions_low(&t->limits, &tgt->limits); - - if (!(tgt->type->features & DM_TARGET_SUPPORTS_BARRIERS)) - t->barriers_supported = 0; - return 0; bad: @@ -797,12 +790,6 @@ int dm_table_complete(struct dm_table *t) check_for_valid_limits(&t->limits); - /* - * We only support barriers if there is exactly one underlying device. - */ - if (!list_is_singular(&t->devices)) - t->barriers_supported = 0; - /* how many indexes will the btree have ? */ leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); @@ -1017,12 +1004,6 @@ struct mapped_device *dm_table_get_md(struct dm_table *t) return t->md; } -int dm_table_barrier_ok(struct dm_table *t) -{ - return t->barriers_supported; -} -EXPORT_SYMBOL(dm_table_barrier_ok); - EXPORT_SYMBOL(dm_vcalloc); EXPORT_SYMBOL(dm_get_device); EXPORT_SYMBOL(dm_put_device); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 51ba1db..a9aa699 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -838,11 +838,7 @@ static int __split_bio(struct mapped_device *md, struct bio *bio) ci.map = dm_get_table(md); if (unlikely(!ci.map)) return -EIO; - if (unlikely(bio_barrier(bio) && !dm_table_barrier_ok(ci.map))) { - dm_table_put(ci.map); - bio_endio(bio, -EOPNOTSUPP); - return 0; - } + ci.md = md; ci.bio = bio; ci.io = alloc_io(md); @@ -926,6 +922,15 @@ static int dm_request(struct request_queue *q, struct bio *bio) struct mapped_device *md = q->queuedata; int cpu; + /* + * There is no use in forwarding any barrier request since we can't + * guarantee it is (or can be) handled by the targets correctly. + */ + if (unlikely(bio_barrier(bio))) { + bio_endio(bio, -EOPNOTSUPP); + return 0; + } + down_read(&md->io_lock); cpu = part_stat_lock(); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 20194e0..7e1af9b 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -52,7 +52,6 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits); * To check the return value from dm_table_find_target(). */ #define dm_target_is_valid(t) ((t)->table) -int dm_table_barrier_ok(struct dm_table *t); /*----------------------------------------------------------------- * A registry of target types. diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 8209e08..27dfba2 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -116,7 +116,6 @@ void dm_put_device(struct dm_target *ti, struct dm_dev *d); /* * Target features */ -#define DM_TARGET_SUPPORTS_BARRIERS 0x00000001 struct target_type { uint64_t features;