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;
 }