@@ -102,6 +102,10 @@ struct blkfront_info
static DEFINE_SPINLOCK(blkif_io_lock);
+static unsigned int nr_minors;
+static unsigned long *minors;
+static DEFINE_SPINLOCK(minor_lock);
+
#define MAXIMUM_OUTSTANDING_BLOCK_REQS \
(BLKIF_MAX_SEGMENTS_PER_REQUEST * BLK_RING_SIZE)
#define GRANT_INVALID_REF 0
@@ -136,6 +140,55 @@ static void add_id_to_freelist(struct blkfront_info *info,
info->shadow_free = id;
}
+static int xlbd_reserve_minors(unsigned int minor, unsigned int nr)
+{
+ unsigned int end = minor + nr;
+ int rc;
+
+ if (end > nr_minors) {
+ unsigned long *bitmap, *old;
+
+ bitmap = kzalloc(BITS_TO_LONGS(end) * sizeof(*bitmap),
+ GFP_KERNEL);
+ if (bitmap == NULL)
+ return -ENOMEM;
+
+ spin_lock(&minor_lock);
+ if (end > nr_minors) {
+ old = minors;
+ memcpy(bitmap, minors,
+ BITS_TO_LONGS(nr_minors) * sizeof(*bitmap));
+ minors = bitmap;
+ nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG;
+ } else
+ old = bitmap;
+ spin_unlock(&minor_lock);
+ kfree(old);
+ }
+
+ spin_lock(&minor_lock);
+ if (find_next_bit(minors, end, minor) >= end) {
+ for (; minor < end; ++minor)
+ __set_bit(minor, minors);
+ rc = 0;
+ } else
+ rc = -EBUSY;
+ spin_unlock(&minor_lock);
+
+ return rc;
+}
+
+static void xlbd_release_minors(unsigned int minor, unsigned int nr)
+{
+ unsigned int end = minor + nr;
+
+ BUG_ON(end > nr_minors);
+ spin_lock(&minor_lock);
+ for (; minor < end; ++minor)
+ __clear_bit(minor, minors);
+ spin_unlock(&minor_lock);
+}
+
static void blkif_restart_queue_callback(void *arg)
{
struct blkfront_info *info = (struct blkfront_info *)arg;
@@ -416,9 +469,14 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
if ((minor % nr_parts) == 0)
nr_minors = nr_parts;
+ err = xlbd_reserve_minors(minor, nr_minors);
+ if (err)
+ goto out;
+ err = -ENODEV;
+
gd = alloc_disk(nr_minors);
if (gd == NULL)
- goto out;
+ goto release;
offset = minor / nr_parts;
@@ -449,7 +507,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
if (xlvbd_init_blk_queue(gd, sector_size)) {
del_gendisk(gd);
- goto out;
+ goto release;
}
info->rq = gd->queue;
@@ -469,6 +527,8 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
return 0;
+ release:
+ xlbd_release_minors(minor, nr_minors);
out:
return err;
}
@@ -923,6 +983,7 @@ static void blkfront_connect(struct blkfront_info *info)
static void blkfront_closing(struct xenbus_device *dev)
{
struct blkfront_info *info = dev_get_drvdata(&dev->dev);
+ unsigned int minor, nr_minors;
unsigned long flags;
dev_dbg(&dev->dev, "blkfront_closing: %s removed\n", dev->nodename);
@@ -942,7 +1003,10 @@ static void blkfront_closing(struct xenbus_device *dev)
/* Flush gnttab callback work. Must be done with no locks held. */
flush_scheduled_work();
+ minor = info->gd->first_minor;
+ nr_minors = info->gd->minors;
del_gendisk(info->gd);
+ xlbd_release_minors(minor, nr_minors);
blk_cleanup_queue(info->rq);
info->rq = NULL;
@@ -1003,7 +1067,10 @@ static int blkfront_remove(struct xenbus_device *dev)
blkif_free(info, 0);
- kfree(info);
+ if(info->users == 0)
+ kfree(info);
+ else
+ info->is_ready = -1;
return 0;
}
@@ -1012,14 +1079,20 @@ static int blkfront_is_ready(struct xenbus_device *dev)
{
struct blkfront_info *info = dev_get_drvdata(&dev->dev);
- return info->is_ready;
+ return info->is_ready >0;
}
static int blkif_open(struct block_device *bdev, fmode_t mode)
{
struct blkfront_info *info = bdev->bd_disk->private_data;
- info->users++;
- return 0;
+ int ret = 0;
+
+ if (info->is_ready < 0)
+ ret = -ENODEV;
+ else
+ info->users++;
+
+ return ret;
}
static int blkif_release(struct gendisk *disk, fmode_t mode)
@@ -1033,7 +1106,10 @@ static int blkif_release(struct gendisk *disk, fmode_t mode)
struct xenbus_device *dev = info->xbdev;
enum xenbus_state state = xenbus_read_driver_state(dev->otherend);
- if (state == XenbusStateClosing && info->is_ready)
+ if(info->is_ready < 0) {
+ blkfront_closing(dev);
+ kfree(info);
+ } else if (state == XenbusStateClosing && info->is_ready)
blkfront_closing(dev);
}
return 0;