LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
To: jens.axboe@oracle.com, agk@redhat.com,
	James.Bottomley@HansenPartnership.com
Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
	dm-devel@redhat.com, j-nomura@ce.jp.nec.com,
	k-ueda@ct.jp.nec.com
Subject: [PATCH 09/13] dm: add target interfaces for request-based dm
Date: Fri, 12 Sep 2008 10:45:48 -0400 (EDT)	[thread overview]
Message-ID: <20080912.104548.48795970.k-ueda@ct.jp.nec.com> (raw)
In-Reply-To: <20080912.103814.74754581.k-ueda@ct.jp.nec.com>

This patch adds the following target interfaces for request-based dm.

  map_rq    : for mapping a request

  rq_end_io : for finishing a request

  busy      : for avoiding performance regression from bio-based dm.
              Target can tell dm core not to map requests now, and
              that may help requests in the block layer queue to be
              bigger by I/O merging.
              In bio-based dm, this behavior is done by device
              drivers which managing the block layer queue.
              But in request-based dm, dm core has to do that
              since dm core manages the block layer queue, and
              target drivers help is needed for it.


Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
---
 include/linux/device-mapper.h |   15 +++++++++++++++
 1 files changed, 15 insertions(+)

Index: 2.6.27-rc6/include/linux/device-mapper.h
===================================================================
--- 2.6.27-rc6.orig/include/linux/device-mapper.h
+++ 2.6.27-rc6/include/linux/device-mapper.h
@@ -46,6 +46,8 @@ typedef void (*dm_dtr_fn) (struct dm_tar
  */
 typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
 			  union map_info *map_context);
+typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone,
+				  union map_info *map_context);
 
 /*
  * Returns:
@@ -58,6 +60,9 @@ typedef int (*dm_map_fn) (struct dm_targ
 typedef int (*dm_endio_fn) (struct dm_target *ti,
 			    struct bio *bio, int error,
 			    union map_info *map_context);
+typedef int (*dm_request_endio_fn) (struct dm_target *ti,
+				    struct request *clone, int error,
+				    union map_info *map_context);
 
 typedef void (*dm_flush_fn) (struct dm_target *ti);
 typedef void (*dm_presuspend_fn) (struct dm_target *ti);
@@ -77,6 +82,13 @@ typedef int (*dm_ioctl_fn) (struct dm_ta
 typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm,
 			    struct bio_vec *biovec, int max_size);
 
+/*
+ * Returns:
+ *    0: The target can handle the next I/O immediately.
+ *    1: The target can't handle the next I/O immediately.
+ */
+typedef int (*dm_busy_fn) (struct dm_target *ti);
+
 void dm_error(const char *message);
 
 /*
@@ -103,7 +115,9 @@ struct target_type {
 	dm_ctr_fn ctr;
 	dm_dtr_fn dtr;
 	dm_map_fn map;
+	dm_map_request_fn map_rq;
 	dm_endio_fn end_io;
+	dm_request_endio_fn rq_end_io;
 	dm_flush_fn flush;
 	dm_presuspend_fn presuspend;
 	dm_postsuspend_fn postsuspend;
@@ -113,6 +127,7 @@ struct target_type {
 	dm_message_fn message;
 	dm_ioctl_fn ioctl;
 	dm_merge_fn merge;
+	dm_busy_fn busy;
 };
 
 struct io_restrictions {

  parent reply	other threads:[~2008-09-12 14:45 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-12 14:38 [PATCH 00/13] request-based dm-multipath Kiyoshi Ueda
2008-09-12 14:40 ` [PATCH 01/13] block: add request update interface Kiyoshi Ueda
2008-09-12 14:41 ` [PATCH 02/13] block: add request submission interface Kiyoshi Ueda
2008-09-14 13:10   ` Boaz Harrosh
2008-09-16 16:06     ` Kiyoshi Ueda
2008-09-16 17:02       ` Jens Axboe
2008-09-16 18:12         ` Kiyoshi Ueda
2008-09-12 14:42 ` [PATCH 03/13] mm: lld busy status exporting interface Kiyoshi Ueda
2008-09-12 14:43 ` [PATCH 04/13] scsi: exports busy status Kiyoshi Ueda
2008-09-12 14:43 ` [PATCH 05/13] block: add a queue flag for request stacking support Kiyoshi Ueda
2008-09-12 14:44 ` [PATCH 06/13] dm: remove unused DM_WQ_FLUSH_ALL Kiyoshi Ueda
2008-09-12 14:44 ` [PATCH 07/13] dm: tidy local_init Kiyoshi Ueda
2008-09-12 14:45 ` [PATCH 08/13] dm: add kmem_cache for request-based dm Kiyoshi Ueda
2008-09-12 14:45 ` Kiyoshi Ueda [this message]
2008-09-12 14:46 ` [PATCH 10/13] dm: add core functions " Kiyoshi Ueda
2008-10-24  7:44   ` [dm-devel] " Nikanth K
2008-10-28 16:00     ` Kiyoshi Ueda
     [not found]     ` <490FB852.3FEE.00C5.1@novell.com>
     [not found]       ` <49102C03020000C50002E257@victor.provo.novell.com>
2008-11-04 15:01         ` Kiyoshi Ueda
2008-09-12 14:46 ` [PATCH 11/13] dm: enable " Kiyoshi Ueda
2008-10-24  7:52   ` [dm-devel] " Nikanth K
2008-10-28 16:02     ` Kiyoshi Ueda
2008-09-12 14:46 ` [PATCH 12/13] dm: reject I/O violating new queue limits Kiyoshi Ueda
2008-09-12 14:47 ` [PATCH 13/13] dm-mpath: convert to request-based Kiyoshi Ueda
2008-10-24  7:55   ` [dm-devel] " Nikanth K
2008-10-28 16:03     ` Kiyoshi Ueda
2008-09-14 13:17 ` [PATCH 00/13] request-based dm-multipath Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20080912.104548.48795970.k-ueda@ct.jp.nec.com \
    --to=k-ueda@ct.jp.nec.com \
    --cc=James.Bottomley@HansenPartnership.com \
    --cc=agk@redhat.com \
    --cc=dm-devel@redhat.com \
    --cc=j-nomura@ce.jp.nec.com \
    --cc=jens.axboe@oracle.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --subject='Re: [PATCH 09/13] dm: add target interfaces for request-based dm' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).