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path: root/drivers/block/xen-blkfront.c
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Diffstat (limited to 'drivers/block/xen-blkfront.c')
-rw-r--r--drivers/block/xen-blkfront.c65
1 files changed, 26 insertions, 39 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index ab735a605cf3..4b33a18c32e0 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -41,7 +41,7 @@
#include <linux/cdrom.h>
#include <linux/module.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/scatterlist.h>
#include <xen/xen.h>
@@ -69,6 +69,7 @@ struct blk_shadow {
unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST];
};
+static DEFINE_MUTEX(blkfront_mutex);
static const struct block_device_operations xlvbd_block_fops;
#define BLK_RING_SIZE __RING_SIZE((struct blkif_sring *)0, PAGE_SIZE)
@@ -95,7 +96,7 @@ struct blkfront_info
struct gnttab_free_callback callback;
struct blk_shadow shadow[BLK_RING_SIZE];
unsigned long shadow_free;
- int feature_barrier;
+ unsigned int feature_flush;
int is_ready;
};
@@ -418,26 +419,12 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
}
-static int xlvbd_barrier(struct blkfront_info *info)
+static void xlvbd_flush(struct blkfront_info *info)
{
- int err;
- const char *barrier;
-
- switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled (drain)"; break;
- case QUEUE_ORDERED_TAG: barrier = "enabled (tag)"; break;
- case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
- default: return -EINVAL;
- }
-
- err = blk_queue_ordered(info->rq, info->feature_barrier);
-
- if (err)
- return err;
-
+ blk_queue_flush(info->rq, info->feature_flush);
printk(KERN_INFO "blkfront: %s: barriers %s\n",
- info->gd->disk_name, barrier);
- return 0;
+ info->gd->disk_name,
+ info->feature_flush ? "enabled" : "disabled");
}
@@ -516,7 +503,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
info->rq = gd->queue;
info->gd = gd;
- xlvbd_barrier(info);
+ xlvbd_flush(info);
if (vdisk_info & VDISK_READONLY)
set_disk_ro(gd, 1);
@@ -662,8 +649,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
printk(KERN_WARNING "blkfront: %s: write barrier op failed\n",
info->gd->disk_name);
error = -EOPNOTSUPP;
- info->feature_barrier = QUEUE_ORDERED_NONE;
- xlvbd_barrier(info);
+ info->feature_flush = 0;
+ xlvbd_flush(info);
}
/* fall through */
case BLKIF_OP_READ:
@@ -1076,20 +1063,20 @@ static void blkfront_connect(struct blkfront_info *info)
/*
* If there's no "feature-barrier" defined, then it means
* we're dealing with a very old backend which writes
- * synchronously; draining will do what needs to get done.
+ * synchronously; nothing to do.
*
- * If there are barriers, then we can do full queued writes
- * with tagged barriers.
- *
- * If barriers are not supported, then there's no much we can
- * do, so just set ordering to NONE.
+ * If there are barriers, then we use flush.
*/
- if (err)
- info->feature_barrier = QUEUE_ORDERED_DRAIN;
- else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_TAG;
- else
- info->feature_barrier = QUEUE_ORDERED_NONE;
+ info->feature_flush = 0;
+
+ /*
+ * The driver doesn't properly handled empty flushes, so
+ * lets disable barrier support for now.
+ */
+#if 0
+ if (!err && barrier)
+ info->feature_flush = REQ_FLUSH;
+#endif
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
if (err) {
@@ -1201,7 +1188,7 @@ static int blkif_open(struct block_device *bdev, fmode_t mode)
struct blkfront_info *info;
int err = 0;
- lock_kernel();
+ mutex_lock(&blkfront_mutex);
info = disk->private_data;
if (!info) {
@@ -1219,7 +1206,7 @@ static int blkif_open(struct block_device *bdev, fmode_t mode)
mutex_unlock(&info->mutex);
out:
- unlock_kernel();
+ mutex_unlock(&blkfront_mutex);
return err;
}
@@ -1229,7 +1216,7 @@ static int blkif_release(struct gendisk *disk, fmode_t mode)
struct block_device *bdev;
struct xenbus_device *xbdev;
- lock_kernel();
+ mutex_lock(&blkfront_mutex);
bdev = bdget_disk(disk, 0);
bdput(bdev);
@@ -1263,7 +1250,7 @@ static int blkif_release(struct gendisk *disk, fmode_t mode)
}
out:
- unlock_kernel();
+ mutex_unlock(&blkfront_mutex);
return 0;
}