From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Anderson Subject: [PATCH 1/2] dm-mpath: Add mutex to synchronize adding and flushing work Date: Sun, 15 Nov 2009 23:38:24 -0800 Message-ID: <20091116073824.4070.71075.stgit@localhost.localdomain> References: <20091116073819.4070.40173.stgit@localhost.localdomain> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20091116073819.4070.40173.stgit@localhost.localdomain> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: dm-devel@redhat.com List-Id: dm-devel.ids Add a mutex to allow possible creators of new work to synchronize with flushing work queues. Signed-off-by: Mike Anderson --- drivers/md/dm-mpath.c | 59 ++++++++++++++++++++++++++++++++----------------- 1 files changed, 38 insertions(+), 21 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 6ffffad..b102959 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -93,6 +93,8 @@ struct multipath { * can resubmit bios on error. */ mempool_t *mpio_pool; + + struct mutex work_mutex; }; /* @@ -198,6 +200,7 @@ static struct multipath *alloc_multipath(struct dm_target *ti) m->queue_io = 1; INIT_WORK(&m->process_queued_ios, process_queued_ios); INIT_WORK(&m->trigger_event, trigger_event); + mutex_init(&m->work_mutex); m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); if (!m->mpio_pool) { kfree(m); @@ -1268,7 +1271,11 @@ static void multipath_presuspend(struct dm_target *ti) static void multipath_postsuspend(struct dm_target *ti) { + struct multipath *m = (struct multipath *) ti->private; + + mutex_lock(&m->work_mutex); flush_multipath_work(); + mutex_unlock(&m->work_mutex); } /* @@ -1407,51 +1414,61 @@ static int multipath_status(struct dm_target *ti, status_type_t type, static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) { - int r; + int r = -EINVAL; struct dm_dev *dev; struct multipath *m = (struct multipath *) ti->private; action_fn action; + mutex_lock(&m->work_mutex); + if (argc == 1) { - if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) - return queue_if_no_path(m, 1, 0); - else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) - return queue_if_no_path(m, 0, 0); + if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) { + r = queue_if_no_path(m, 1, 0); + goto out; + } else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) { + r = queue_if_no_path(m, 0, 0); + goto out; + } } - if (argc != 2) - goto error; + if (argc != 2) { + DMWARN("Unrecognised multipath message received."); + goto out; + } - if (!strnicmp(argv[0], MESG_STR("disable_group"))) - return bypass_pg_num(m, argv[1], 1); - else if (!strnicmp(argv[0], MESG_STR("enable_group"))) - return bypass_pg_num(m, argv[1], 0); - else if (!strnicmp(argv[0], MESG_STR("switch_group"))) - return switch_pg_num(m, argv[1]); - else if (!strnicmp(argv[0], MESG_STR("reinstate_path"))) + if (!strnicmp(argv[0], MESG_STR("disable_group"))) { + r = bypass_pg_num(m, argv[1], 1); + goto out; + } else if (!strnicmp(argv[0], MESG_STR("enable_group"))) { + r = bypass_pg_num(m, argv[1], 0); + goto out; + } else if (!strnicmp(argv[0], MESG_STR("switch_group"))) { + r = switch_pg_num(m, argv[1]); + goto out; + } else if (!strnicmp(argv[0], MESG_STR("reinstate_path"))) action = reinstate_path; else if (!strnicmp(argv[0], MESG_STR("fail_path"))) action = fail_path; - else - goto error; + else { + DMWARN("Unrecognised multipath message received."); + goto out; + } r = dm_get_device(ti, argv[1], ti->begin, ti->len, dm_table_get_mode(ti->table), &dev); if (r) { DMWARN("message: error getting device %s", argv[1]); - return -EINVAL; + goto out; } r = action_dev(m, dev, action); dm_put_device(ti, dev); +out: + mutex_unlock(&m->work_mutex); return r; - -error: - DMWARN("Unrecognised multipath message received."); - return -EINVAL; } static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,