[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.25 / patches.suse / dm-mpath-accept-failed-paths

From: Hannes Reinecke <hare@suse.de>
Subject: Accept failed paths for multipath maps
References: bnc#458037,bnc#458393

The multipath kernel module is rejecting any map with an invalid
device. However, as the multipathd is processing the events serially
it will try to push a map with invalid devices if more than one
device failed at the same time.
So we can as well accept those maps and make sure to mark the
paths as down.

Signed-off-by: Hannes Reinecke <hare@suse.de>

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 510fd26..95feacd 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -141,7 +141,8 @@ static void deactivate_path(struct work_struct *work)
 	struct pgpath *pgpath =
 		container_of(work, struct pgpath, deactivate_path);
 
-	blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
+	if (pgpath->path.dev)
+		blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
 }
 
 static struct priority_group *alloc_priority_group(void)
@@ -253,6 +254,11 @@ static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg,
 
 	m->current_pgpath = path_to_pgpath(path);
 
+	if (!m->current_pgpath->path.dev) {
+		m->current_pgpath = NULL;
+		return -ENODEV;
+	}
+
 	if (m->current_pg != pg)
 		__switch_pg(m, m->current_pgpath);
 
@@ -570,6 +576,7 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
 {
 	int r;
 	struct pgpath *p;
+	char *path;
 	struct multipath *m = ti->private;
 
 	/* we need at least a path arg */
@@ -582,14 +589,37 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
 	if (!p)
 		return NULL;
 
-	r = dm_get_device(ti, shift(as), ti->begin, ti->len,
+	path = shift(as);
+	r = dm_get_device(ti, path, ti->begin, ti->len,
 			  dm_table_get_mode(ti->table), &p->path.dev);
 	if (r) {
-		ti->error = "error getting device";
-		goto bad;
+		unsigned major, minor;
+
+		/* Try to add a failed device */
+		if (r == -ENXIO && sscanf(path, "%u:%u", &major, &minor) == 2) {
+			dev_t dev;
+
+			/* Extract the major/minor numbers */
+			dev = MKDEV(major, minor);
+			if (MAJOR(dev) != major || MINOR(dev) != minor) {
+				/* Nice try, didn't work */
+				DMWARN("Invalid device path %s", path);
+				ti->error = "error converting devnum";
+				goto bad;
+			}
+			DMWARN("adding disabled device %d:%d", major, minor);
+			p->path.dev = NULL;
+			format_dev_t(p->path.pdev, dev);
+			p->is_active = 0;
+		} else {
+			ti->error = "error getting device";
+			goto bad;
+		}
+	} else {
+		memcpy(p->path.pdev, p->path.dev->name, 16);
 	}
 
-	if (m->hw_handler_name) {
+	if (m->hw_handler_name && p->path.dev) {
 		struct request_queue *q = bdev_get_queue(p->path.dev->bdev);
 
 		r = scsi_dh_attach(q, m->hw_handler_name);
@@ -880,7 +910,7 @@ static int fail_path(struct pgpath *pgpath)
 	if (!pgpath->is_active)
 		goto out;
 
-	DMWARN("Failing path %s.", pgpath->path.dev->name);
+	DMWARN("Failing path %s.", pgpath->path.pdev);
 
 	pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
 	pgpath->is_active = 0;
@@ -892,7 +922,7 @@ static int fail_path(struct pgpath *pgpath)
 		m->current_pgpath = NULL;
 
 	dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
-		      pgpath->path.dev->name, m->nr_valid_paths);
+		       pgpath->path.pdev, m->nr_valid_paths);
 
 	queue_work(kmultipathd, &m->trigger_event);
 	queue_work(kmultipathd, &pgpath->deactivate_path);
@@ -917,6 +947,12 @@ static int reinstate_path(struct pgpath *pgpath)
 	if (pgpath->is_active)
 		goto out;
 
+	if (!pgpath->path.dev) {
+		DMWARN("Cannot reinstate disabled path %s", pgpath->path.pdev);
+		r = -ENODEV;
+		goto out;
+	}
+
 	if (!pgpath->pg->ps.type->reinstate_path) {
 		DMWARN("Reinstate path not supported by path selector %s",
 		       pgpath->pg->ps.type->name);
@@ -935,7 +971,7 @@ static int reinstate_path(struct pgpath *pgpath)
 		queue_work(kmultipathd, &m->process_queued_ios);
 
 	dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
-		      pgpath->path.dev->name, m->nr_valid_paths);
+		       pgpath->path.pdev, m->nr_valid_paths);
 
 	queue_work(kmultipathd, &m->trigger_event);
 
@@ -955,6 +991,9 @@ static int action_dev(struct multipath *m, struct dm_dev *dev,
 	struct pgpath *pgpath;
 	struct priority_group *pg;
 
+	if (!dev)
+		return 0;
+
 	list_for_each_entry(pg, &m->priority_groups, list) {
 		list_for_each_entry(pgpath, &pg->pgpaths, list) {
 			if (pgpath->path.dev == dev)
@@ -1124,11 +1163,12 @@ static void pg_init_done(struct dm_path *path, int errors)
 
 static void activate_path(struct work_struct *work)
 {
-	int ret;
+	int ret = SCSI_DH_DEV_OFFLINED;
 	struct pgpath *pgpath =
 		container_of(work, struct pgpath, activate_path);
 
-	ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
+	if (pgpath->path.dev)
+		ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
 	pg_init_done(&pgpath->path, ret);
 }
 
@@ -1295,7 +1335,7 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
 			       pg->ps.type->info_args);
 
 			list_for_each_entry(p, &pg->pgpaths, list) {
-				DMEMIT("%s %s %u ", p->path.dev->name,
+				DMEMIT("%s %s %u ", p->path.pdev,
 				       p->is_active ? "A" : "F",
 				       p->fail_count);
 				if (pg->ps.type->status)
@@ -1321,7 +1361,7 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
 			       pg->ps.type->table_args);
 
 			list_for_each_entry(p, &pg->pgpaths, list) {
-				DMEMIT("%s ", p->path.dev->name);
+				DMEMIT("%s ", p->path.pdev);
 				if (pg->ps.type->status)
 					sz += pg->ps.type->status(&pg->ps,
 					      &p->path, type, result + sz,
@@ -1403,7 +1443,7 @@ static int multipath_ioctl(struct dm_target *ti, struct inode *inode,
 	if (!m->current_pgpath)
 		__choose_pgpath(m, 1 << 19); /* Assume 512KB */
 
-	if (m->current_pgpath) {
+	if (m->current_pgpath && m->current_pgpath->path.dev) {
 		bdev = m->current_pgpath->path.dev->bdev;
 		fake_dentry.d_inode = bdev->bd_inode;
 		fake_file.f_mode = m->current_pgpath->path.dev->mode;
diff --git a/drivers/md/dm-mpath.h b/drivers/md/dm-mpath.h
index e230f71..f97388d 100644
--- a/drivers/md/dm-mpath.h
+++ b/drivers/md/dm-mpath.h
@@ -12,6 +12,7 @@
 struct dm_dev;
 
 struct dm_path {
+	char pdev[16];		/* Requested physical device */
 	struct dm_dev *dev;	/* Read-only */
 	void *pscontext;	/* For path-selector use */
 };
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 1514e84..ee61b82 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -566,6 +566,9 @@ int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
  */
 void dm_put_device(struct dm_target *ti, struct dm_dev *dd)
 {
+	if (!dd)
+		return;
+
 	if (atomic_dec_and_test(&dd->count)) {
 		close_dev(dd, ti->table->md);
 		list_del(&dd->list);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6783f91..134995e 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1503,6 +1503,9 @@ static void map_request(struct dm_target *ti, struct request *rq,
 	tio->ti = ti;
 	atomic_inc(&md->pending);
 
+#if 0
+	/* This might trigger accidentally */
+
 	/*
 	 * Although submitted requests to the md->queue are checked against
 	 * the table/queue limitations at the submission time, the limitations
@@ -1525,6 +1528,7 @@ static void map_request(struct dm_target *ti, struct request *rq,
 		dm_kill_request(clone, r);
 		return;
 	}
+#endif
 
 	r = ti->type->map_rq(ti, clone, &tio->info);
 	switch (r) {
Commit	Line	Data
00e5a55c BS	1	From: Hannes Reinecke <hare@suse.de>
	2	Subject: Accept failed paths for multipath maps
	3	References: bnc#458037,bnc#458393
	4
	5	The multipath kernel module is rejecting any map with an invalid
	6	device. However, as the multipathd is processing the events serially
	7	it will try to push a map with invalid devices if more than one
	8	device failed at the same time.
	9	So we can as well accept those maps and make sure to mark the
	10	paths as down.
	11
	12	Signed-off-by: Hannes Reinecke <hare@suse.de>
	13
	14	diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
	15	index 510fd26..95feacd 100644
	16	--- a/drivers/md/dm-mpath.c
	17	+++ b/drivers/md/dm-mpath.c
	18	@@ -141,7 +141,8 @@ static void deactivate_path(struct work_struct *work)
	19	struct pgpath *pgpath =
	20	container_of(work, struct pgpath, deactivate_path);
	21
	22	- blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
	23	+ if (pgpath->path.dev)
	24	+ blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
	25	}
	26
	27	static struct priority_group *alloc_priority_group(void)
	28	@@ -253,6 +254,11 @@ static int __choose_path_in_pg(struct multipath m, struct priority_group pg,
	29
	30	m->current_pgpath = path_to_pgpath(path);
	31
	32	+ if (!m->current_pgpath->path.dev) {
	33	+ m->current_pgpath = NULL;
	34	+ return -ENODEV;
	35	+ }
	36	+
	37	if (m->current_pg != pg)
	38	__switch_pg(m, m->current_pgpath);
	39
	40	@@ -570,6 +576,7 @@ static struct pgpath parse_path(struct arg_set as, struct path_selector *ps,
	41	{
	42	int r;
	43	struct pgpath *p;
	44	+ char *path;
	45	struct multipath *m = ti->private;
	46
	47	/* we need at least a path arg */
	48	@@ -582,14 +589,37 @@ static struct pgpath parse_path(struct arg_set as, struct path_selector *ps,
	49	if (!p)
	50	return NULL;
	51
	52	- r = dm_get_device(ti, shift(as), ti->begin, ti->len,
	53	+ path = shift(as);
	54	+ r = dm_get_device(ti, path, ti->begin, ti->len,
	55	dm_table_get_mode(ti->table), &p->path.dev);
	56	if (r) {
	57	- ti->error = "error getting device";
	58	- goto bad;
	59	+ unsigned major, minor;
	60	+
	61	+ /* Try to add a failed device */
	62	+ if (r == -ENXIO && sscanf(path, "%u:%u", &major, &minor) == 2) {
	63	+ dev_t dev;
	64	+
65	+ /* Extract the major/minor numbers */
66	+ dev = MKDEV(major, minor);
67	+ if (MAJOR(dev) != major \|\| MINOR(dev) != minor) {
68	+ /* Nice try, didn't work */
69	+ DMWARN("Invalid device path %s", path);
70	+ ti->error = "error converting devnum";
71	+ goto bad;
72	+ }
73	+ DMWARN("adding disabled device %d:%d", major, minor);
74	+ p->path.dev = NULL;
75	+ format_dev_t(p->path.pdev, dev);
76	+ p->is_active = 0;
77	+ } else {
78	+ ti->error = "error getting device";
79	+ goto bad;
80	+ }
81	+ } else {
82	+ memcpy(p->path.pdev, p->path.dev->name, 16);
83	}
84
85	- if (m->hw_handler_name) {
86	+ if (m->hw_handler_name && p->path.dev) {
87	struct request_queue *q = bdev_get_queue(p->path.dev->bdev);
88
89	r = scsi_dh_attach(q, m->hw_handler_name);
90	@@ -880,7 +910,7 @@ static int fail_path(struct pgpath *pgpath)
91	if (!pgpath->is_active)
92	goto out;
93
94	- DMWARN("Failing path %s.", pgpath->path.dev->name);
95	+ DMWARN("Failing path %s.", pgpath->path.pdev);
96
97	pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
98	pgpath->is_active = 0;
99	@@ -892,7 +922,7 @@ static int fail_path(struct pgpath *pgpath)
100	m->current_pgpath = NULL;
101
102	dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
103	- pgpath->path.dev->name, m->nr_valid_paths);
104	+ pgpath->path.pdev, m->nr_valid_paths);
105
106	queue_work(kmultipathd, &m->trigger_event);
107	queue_work(kmultipathd, &pgpath->deactivate_path);
108	@@ -917,6 +947,12 @@ static int reinstate_path(struct pgpath *pgpath)
109	if (pgpath->is_active)
110	goto out;
111
112	+ if (!pgpath->path.dev) {
113	+ DMWARN("Cannot reinstate disabled path %s", pgpath->path.pdev);
114	+ r = -ENODEV;
115	+ goto out;
116	+ }
117	+
118	if (!pgpath->pg->ps.type->reinstate_path) {
119	DMWARN("Reinstate path not supported by path selector %s",
120	pgpath->pg->ps.type->name);
121	@@ -935,7 +971,7 @@ static int reinstate_path(struct pgpath *pgpath)
122	queue_work(kmultipathd, &m->process_queued_ios);
123
124	dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
125	- pgpath->path.dev->name, m->nr_valid_paths);
126	+ pgpath->path.pdev, m->nr_valid_paths);
127
128	queue_work(kmultipathd, &m->trigger_event);
129
130	@@ -955,6 +991,9 @@ static int action_dev(struct multipath m, struct dm_dev dev,
131	struct pgpath *pgpath;
132	struct priority_group *pg;
133
134	+ if (!dev)
135	+ return 0;
136	+
137	list_for_each_entry(pg, &m->priority_groups, list) {
138	list_for_each_entry(pgpath, &pg->pgpaths, list) {
139	if (pgpath->path.dev == dev)
140	@@ -1124,11 +1163,12 @@ static void pg_init_done(struct dm_path *path, int errors)
141
142	static void activate_path(struct work_struct *work)
143	{
144	- int ret;
145	+ int ret = SCSI_DH_DEV_OFFLINED;
146	struct pgpath *pgpath =
147	container_of(work, struct pgpath, activate_path);
148
149	- ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
150	+ if (pgpath->path.dev)
151	+ ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
152	pg_init_done(&pgpath->path, ret);
153	}
154
155	@@ -1295,7 +1335,7 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
156	pg->ps.type->info_args);
157
158	list_for_each_entry(p, &pg->pgpaths, list) {
159	- DMEMIT("%s %s %u ", p->path.dev->name,
160	+ DMEMIT("%s %s %u ", p->path.pdev,
161	p->is_active ? "A" : "F",
162	p->fail_count);
163	if (pg->ps.type->status)
164	@@ -1321,7 +1361,7 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
165	pg->ps.type->table_args);
166
167	list_for_each_entry(p, &pg->pgpaths, list) {
168	- DMEMIT("%s ", p->path.dev->name);
169	+ DMEMIT("%s ", p->path.pdev);
170	if (pg->ps.type->status)
171	sz += pg->ps.type->status(&pg->ps,
172	&p->path, type, result + sz,
173	@@ -1403,7 +1443,7 @@ static int multipath_ioctl(struct dm_target ti, struct inode inode,
174	if (!m->current_pgpath)
175	__choose_pgpath(m, 1 << 19); /* Assume 512KB */
176
177	- if (m->current_pgpath) {
178	+ if (m->current_pgpath && m->current_pgpath->path.dev) {
179	bdev = m->current_pgpath->path.dev->bdev;
180	fake_dentry.d_inode = bdev->bd_inode;
181	fake_file.f_mode = m->current_pgpath->path.dev->mode;
182	diff --git a/drivers/md/dm-mpath.h b/drivers/md/dm-mpath.h
183	index e230f71..f97388d 100644
184	--- a/drivers/md/dm-mpath.h
185	+++ b/drivers/md/dm-mpath.h
186	@@ -12,6 +12,7 @@
187	struct dm_dev;
188
189	struct dm_path {
190	+ char pdev[16]; /* Requested physical device */
191	struct dm_dev dev; / Read-only */
192	void pscontext; / For path-selector use */
193	};
194	diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
195	index 1514e84..ee61b82 100644
196	--- a/drivers/md/dm-table.c
197	+++ b/drivers/md/dm-table.c
198	@@ -566,6 +566,9 @@ int dm_get_device(struct dm_target ti, const char path, sector_t start,
199	*/
200	void dm_put_device(struct dm_target ti, struct dm_dev dd)
201	{
202	+ if (!dd)
203	+ return;
204	+
205	if (atomic_dec_and_test(&dd->count)) {
206	close_dev(dd, ti->table->md);
207	list_del(&dd->list);
208	diff --git a/drivers/md/dm.c b/drivers/md/dm.c
209	index 6783f91..134995e 100644
210	--- a/drivers/md/dm.c
211	+++ b/drivers/md/dm.c
212	@@ -1503,6 +1503,9 @@ static void map_request(struct dm_target ti, struct request rq,
213	tio->ti = ti;
214	atomic_inc(&md->pending);
215
216	+#if 0
217	+ /* This might trigger accidentally */
218	+
219	/*
220	* Although submitted requests to the md->queue are checked against
221	* the table/queue limitations at the submission time, the limitations
222	@@ -1525,6 +1528,7 @@ static void map_request(struct dm_target ti, struct request rq,
223	dm_kill_request(clone, r);
224	return;
225	}
226	+#endif
227
228	r = ti->type->map_rq(ti, clone, &tio->info);
229	switch (r) {