Attachment 314160 Details for Bug 438761 – Do not remove Hardware Handler code

Do not remove Hardware Handler code

do_not_remove_dm_hardware_handler_stuff (text/plain), 5.40 KB, created by IBM Bug Proxy on 2008-08-13 00:51:33 UTC

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Creator: IBM Bug Proxy

Created: 2008-08-13 00:51:33 UTC

Size: 5.40 KB

patch

obsolete

>Leave the hardware handler infrastructure for backward compatibility and
>ABI reasons.
>
>Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
>-----
>Index: linux-2.6.18.ppc64/drivers/md/dm-mpath.c
>===================================================================
>--- linux-2.6.18.ppc64.orig/drivers/md/dm-mpath.c
>+++ linux-2.6.18.ppc64/drivers/md/dm-mpath.c
>@@ -62,6 +62,7 @@ struct multipath {
> 
> 	spinlock_t lock;
> 
>+	struct hw_handler hw_handler;
> 	const char *hw_handler_name;
> 	unsigned nr_priority_groups;
> 	struct list_head priority_groups;
>@@ -201,12 +202,17 @@ static struct multipath *alloc_multipath
> static void free_multipath(struct multipath *m)
> {
> 	struct priority_group *pg, *tmp;
>+	struct hw_handler *hwh = &m->hw_handler;
> 
> 	list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) {
> 		list_del(&pg->list);
> 		free_priority_group(pg, m->ti);
> 	}
> 
>+	if (hwh->type) {
>+		hwh->type->destroy(hwh);
>+		dm_put_hw_handler(hwh->type);
>+	}
> 	kfree(m->hw_handler_name);
> 	mempool_destroy(m->mpio_pool);
> 	kfree(m);
>@@ -219,10 +225,12 @@ static void free_multipath(struct multip
> 
> static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
> {
>+	struct hw_handler *hwh = &m->hw_handler;
>+
> 	m->current_pg = pgpath->pg;
> 
> 	/* Must we initialise the PG first, and queue I/O till it's ready? */
>-	if (m->hw_handler_name) {
>+	if ((hwh->type && hwh->type->pg_init) || m->hw_handler_name) {
> 		m->pg_init_required = 1;
> 		m->queue_io = 1;
> 	} else {
>@@ -402,6 +410,7 @@ static void dispatch_queued_ios(struct m
> static void process_queued_ios(void *data)
> {
> 	struct multipath *m = (struct multipath *) data;
>+	struct hw_handler *hwh = &m->hw_handler;
> 	struct pgpath *pgpath = NULL;
> 	unsigned init_required = 0, must_queue = 1;
> 	unsigned long flags;
>@@ -431,9 +440,15 @@ out:
> 	spin_unlock_irqrestore(&m->lock, flags);
> 
> 	if (init_required) {
>-		struct path *path = &pgpath->path;
>-		int ret = scsi_dh_activate(bdev_get_queue(path->dev->bdev));
>-		pg_init_done(path, ret);
>+		if (hwh->type)
>+			hwh->type->pg_init(hwh, pgpath->pg->bypassed,
>+							 &pgpath->path);
>+		else {
>+			int ret;
>+			struct path *path = &pgpath->path;
>+			ret = scsi_dh_activate(bdev_get_queue(path->dev->bdev));
>+			pg_init_done(path, ret);
>+		}
> 	}
> 
> 	if (!must_queue)
>@@ -657,13 +672,16 @@ static struct priority_group *parse_prio
> static int parse_hw_handler(struct arg_set *as, struct multipath *m,
> 			    struct dm_target *ti)
> {
>+	int r;
>+	struct hw_handler_type *hwht;
> 	unsigned hw_argc;
> 
> 	static struct param _params[] = {
> 		{0, 1024, "invalid number of hardware handler args"},
> 	};
> 
>-	if (read_param(_params, shift(as), &hw_argc, &ti->error))
>+	r = read_param(_params, shift(as), &hw_argc, &ti->error);
>+	if (r)
> 		return -EINVAL;
> 
> 	if (!hw_argc)
>@@ -671,16 +689,32 @@ static int parse_hw_handler(struct arg_s
> 
> 	m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL);
> 	request_module("scsi_dh_%s", m->hw_handler_name);
>-	if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {
>-		ti->error = "unknown hardware handler type";
>-		kfree(m->hw_handler_name);
>-		m->hw_handler_name = NULL;
>-		return -EINVAL;
>+	if (scsi_dh_handler_exist(m->hw_handler_name))
>+		goto done;
>+
>+	hwht = dm_get_hw_handler(m->hw_handler_name);
>+	if (!hwht) {
>+  		ti->error = "unknown hardware handler type";
>+		r = -EINVAL;
>+		goto free_hw_handler_name;
> 	}
> 
>-	consume(as, hw_argc - 1);
>+	r = hwht->create(&m->hw_handler, hw_argc - 1, as->argv);
>+	if (r) {
>+		dm_put_hw_handler(hwht);
>+		ti->error = "hardware handler constructor failed";
>+		goto free_hw_handler_name;
>+  	}
>+	m->hw_handler.type = hwht;
> 
>-	return 0;
>+free_hw_handler_name:
>+	kfree(m->hw_handler_name);
>+	m->hw_handler_name = NULL;
>+
>+done:
>+  	consume(as, hw_argc - 1);
>+
>+	return r;
> }
> 
> static int parse_features(struct arg_set *as, struct multipath *m,
>@@ -1130,6 +1164,8 @@ static void pg_init_done(struct path *pa
> static int do_end_io(struct multipath *m, struct bio *bio,
> 		     int error, struct mpath_io *mpio)
> {
>+	struct hw_handler *hwh = &m->hw_handler;
>+	unsigned err_flags = MP_FAIL_PATH;	/* Default behavior */
> 	unsigned long flags;
> 
> 	if (!error)
>@@ -1156,9 +1192,21 @@ static int do_end_io(struct multipath *m
> 	}
> 	spin_unlock_irqrestore(&m->lock, flags);
> 
>-	if (mpio->pgpath)
>-		fail_path(mpio->pgpath);
>+	if (hwh->type && hwh->type->error)
>+		err_flags = hwh->type->error(hwh, bio);
> 
>+	if (mpio->pgpath) {
>+		if (hwh->type) {
>+			if (err_flags & MP_FAIL_PATH)
>+				fail_path(mpio->pgpath);
>+
>+			if (err_flags & MP_BYPASS_PG)
>+				bypass_pg(m, mpio->pgpath->pg, 1);
>+		} else
>+			fail_path(mpio->pgpath);
>+	}
>+	if (hwh->type && (err_flags & MP_ERROR_IO))
>+		return -EIO;
>       requeue:
> 	dm_bio_restore(&mpio->details, bio);
> 
>@@ -1242,6 +1290,7 @@ static int multipath_status(struct dm_ta
> 	int sz = 0;
> 	unsigned long flags;
> 	struct multipath *m = (struct multipath *) ti->private;
>+	struct hw_handler *hwh = &m->hw_handler;
> 	struct priority_group *pg;
> 	struct pgpath *p;
> 	unsigned pg_num;
>@@ -1261,10 +1310,14 @@ static int multipath_status(struct dm_ta
> 			DMEMIT("pg_init_retries %u ", m->pg_init_retries);
> 	}
> 
>-	if (!m->hw_handler_name || type == STATUSTYPE_INFO)
>+	if (hwh->type && hwh->type->status)
>+		sz += hwh->type->status(hwh, type, result + sz, maxlen - sz);
>+
>+	if ((!hwh->type && !m->hw_handler_name) || type == STATUSTYPE_INFO)
> 		DMEMIT("0 ");
> 	else
>-		DMEMIT("1 %s ", m->hw_handler_name);
>+		DMEMIT("1 %s ", m->hw_handler_name ? m->hw_handler_name :
>+				hwh->type->name);
> 
> 	DMEMIT("%u ", m->nr_priority_groups);
>

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