summaryrefslogtreecommitdiff
path: root/drivers/md/dm-stripe.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/md/dm-stripe.c')
-rw-r--r--drivers/md/dm-stripe.c82
1 files changed, 81 insertions, 1 deletions
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 969944a8aba2..7c5e2a0c3f2d 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -14,10 +14,13 @@
#include <linux/log2.h>
#define DM_MSG_PREFIX "striped"
+#define DM_IO_ERROR_THRESHOLD 15
struct stripe {
struct dm_dev *dev;
sector_t physical_start;
+
+ atomic_t error_count;
};
struct stripe_c {
@@ -30,9 +33,29 @@ struct stripe_c {
uint32_t chunk_shift;
sector_t chunk_mask;
+ /* Needed for handling events */
+ struct dm_target *ti;
+
+ /* Work struct used for triggering events*/
+ struct work_struct kstriped_ws;
+
struct stripe stripe[0];
};
+static struct workqueue_struct *kstriped;
+
+/*
+ * An event is triggered whenever a drive
+ * drops out of a stripe volume.
+ */
+static void trigger_event(struct work_struct *work)
+{
+ struct stripe_c *sc = container_of(work, struct stripe_c, kstriped_ws);
+
+ dm_table_event(sc->ti->table);
+
+}
+
static inline struct stripe_c *alloc_context(unsigned int stripes)
{
size_t len;
@@ -63,6 +86,7 @@ static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
return -ENXIO;
sc->stripe[stripe].physical_start = start;
+
return 0;
}
@@ -135,6 +159,11 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
return -ENOMEM;
}
+ INIT_WORK(&sc->kstriped_ws, trigger_event);
+
+ /* Set pointer to dm target; used in trigger_event */
+ sc->ti = ti;
+
sc->stripes = stripes;
sc->stripe_width = width;
ti->split_io = chunk_size;
@@ -158,9 +187,11 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
kfree(sc);
return r;
}
+ atomic_set(&(sc->stripe[i].error_count), 0);
}
ti->private = sc;
+
return 0;
}
@@ -172,6 +203,7 @@ static void stripe_dtr(struct dm_target *ti)
for (i = 0; i < sc->stripes; i++)
dm_put_device(ti, sc->stripe[i].dev);
+ flush_workqueue(kstriped);
kfree(sc);
}
@@ -213,13 +245,52 @@ static int stripe_status(struct dm_target *ti,
return 0;
}
+static int stripe_end_io(struct dm_target *ti, struct bio *bio,
+ int error, union map_info *map_context)
+{
+ unsigned i;
+ char major_minor[16];
+ struct stripe_c *sc = ti->private;
+
+ if (!error)
+ return 0; /* I/O complete */
+
+ if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio))
+ return error;
+
+ if (error == -EOPNOTSUPP)
+ return error;
+
+ memset(major_minor, 0, sizeof(major_minor));
+ sprintf(major_minor, "%d:%d",
+ bio->bi_bdev->bd_disk->major,
+ bio->bi_bdev->bd_disk->first_minor);
+
+ /*
+ * Test to see which stripe drive triggered the event
+ * and increment error count for all stripes on that device.
+ * If the error count for a given device exceeds the threshold
+ * value we will no longer trigger any further events.
+ */
+ for (i = 0; i < sc->stripes; i++)
+ if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
+ atomic_inc(&(sc->stripe[i].error_count));
+ if (atomic_read(&(sc->stripe[i].error_count)) <
+ DM_IO_ERROR_THRESHOLD)
+ queue_work(kstriped, &sc->kstriped_ws);
+ }
+
+ return error;
+}
+
static struct target_type stripe_target = {
.name = "striped",
- .version= {1, 0, 2},
+ .version = {1, 1, 0},
.module = THIS_MODULE,
.ctr = stripe_ctr,
.dtr = stripe_dtr,
.map = stripe_map,
+ .end_io = stripe_end_io,
.status = stripe_status,
};
@@ -231,6 +302,13 @@ int __init dm_stripe_init(void)
if (r < 0)
DMWARN("target registration failed");
+ kstriped = create_singlethread_workqueue("kstriped");
+ if (!kstriped) {
+ DMERR("failed to create workqueue kstriped");
+ dm_unregister_target(&stripe_target);
+ return -ENOMEM;
+ }
+
return r;
}
@@ -239,5 +317,7 @@ void dm_stripe_exit(void)
if (dm_unregister_target(&stripe_target))
DMWARN("target unregistration failed");
+ destroy_workqueue(kstriped);
+
return;
}