[PATCH v2] blkfront: don't change to closing if we're busy
From: Andrew Jones <hidden>
Date: 2012-02-17 16:59:19
Also in:
xen-devel
Subsystem:
block layer, the rest, xen block subsystem, xen hypervisor interface · Maintainers:
Jens Axboe, Linus Torvalds, Roger Pau Monné, Juergen Gross, Stefano Stabellini
We just reported to xenbus that we can't close yet, because we're still in use. So we shouldn't then immediately tell xenbus that we are closing. If we do, then we risk bypassing the chance to complain again, if we're told to close again, and we're still in use. The reason this code was here was to implement a deferred close. We can still support this feature by adding a member to our private data, and setting that instead. Besides being able to complain each time, this patch fixes a problem when running on hosts with legacy tools that may interpret the lack of a complaint or state=Closing incorrectly, and then yank the device out from under the guest. Signed-off-by: Andrew Jones <redacted> --- drivers/block/xen-blkfront.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 2f22874..d7f2e03 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c@@ -103,6 +103,7 @@ struct blkfront_info unsigned int discard_granularity; unsigned int discard_alignment; int is_ready; + int closing; }; static DEFINE_SPINLOCK(blkif_io_lock);
@@ -1134,7 +1135,7 @@ blkfront_closing(struct blkfront_info *info) if (bdev->bd_openers) { xenbus_dev_error(xbdev, -EBUSY, "Device in use; refusing to close"); - xenbus_switch_state(xbdev, XenbusStateClosing); + info->closing = 1; } else { xlvbd_release_gendisk(info); xenbus_frontend_closed(xbdev);
@@ -1423,8 +1424,10 @@ static int blkif_release(struct gendisk *disk, fmode_t mode) mutex_lock(&info->mutex); xbdev = info->xbdev; - if (xbdev && xbdev->state == XenbusStateClosing) { + if (xbdev && (xbdev->state == XenbusStateClosing || info->closing)) { /* pending switch to state closed */ + if (xbdev->state != XenbusStateClosing) + xenbus_switch_state(xbdev, XenbusStateClosing); dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); xlvbd_release_gendisk(info); xenbus_frontend_closed(info->xbdev);
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1.7.7.5