Li Dongyang
2011-Nov-10 07:52 UTC
[Xen-devel] [PATCH V1] xen-blkback: convert hole punching to discard request on loop devices
As of dfaa2ef68e80c378e610e3c8c536f1c239e8d3ef, loop devices support
discard request now. We could just issue a discard request, and
the loop driver will punch the hole for us, so we don''t need to touch
the internals of loop device and punch the hole ourselves, Thanks.
V0->V1: rebased on Konrand''s devel/for-jens-3.3
Signed-off-by: Li Dongyang <lidongyang@novell.com>
---
drivers/block/xen-blkback/blkback.c | 19 ++-----------------
1 files changed, 2 insertions(+), 17 deletions(-)
diff --git a/drivers/block/xen-blkback/blkback.c
b/drivers/block/xen-blkback/blkback.c
index 3283801..b75d4a9 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -39,9 +39,6 @@
#include <linux/list.h>
#include <linux/delay.h>
#include <linux/freezer.h>
-#include <linux/loop.h>
-#include <linux/falloc.h>
-#include <linux/fs.h>
#include <xen/events.h>
#include <xen/page.h>
@@ -426,27 +423,15 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
blkif->st_ds_req++;
xen_blkif_get(blkif);
- if (blkif->blk_backend_type == BLKIF_BACKEND_PHY) {
+ if (blkif->blk_backend_type == BLKIF_BACKEND_PHY ||
+ blkif->blk_backend_type == BLKIF_BACKEND_FILE) {
unsigned long secure = (blkif->vbd.discard_secure &&
(req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
BLKDEV_DISCARD_SECURE : 0;
- /* just forward the discard request */
err = blkdev_issue_discard(bdev,
req->u.discard.sector_number,
req->u.discard.nr_sectors,
GFP_KERNEL, secure);
- } else if (blkif->blk_backend_type == BLKIF_BACKEND_FILE) {
- /* punch a hole in the backing file */
- struct loop_device *lo = bdev->bd_disk->private_data;
- struct file *file = lo->lo_backing_file;
-
- if (file->f_op->fallocate)
- err = file->f_op->fallocate(file,
- FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE,
- req->u.discard.sector_number << 9,
- req->u.discard.nr_sectors << 9);
- else
- err = -EOPNOTSUPP;
} else
err = -EOPNOTSUPP;
--
1.7.7
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