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xen/blkback: Fix two races in the handling of barrier requests.
There are two windows of opportunity to cause a race when processing a barrier request. This patch fixes this. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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parent
dda1852802
commit
6927d92091
1 changed files with 5 additions and 5 deletions
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@ -456,15 +456,15 @@ static void xen_blk_drain_io(struct xen_blkif *blkif)
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{
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atomic_set(&blkif->drain, 1);
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do {
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/* The initial value is one, and one refcnt taken at the
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* start of the xen_blkif_schedule thread. */
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if (atomic_read(&blkif->refcnt) <= 2)
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break;
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wait_for_completion_interruptible_timeout(
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&blkif->drain_complete, HZ);
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if (!atomic_read(&blkif->drain))
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break;
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/* The initial value is one, and one refcnt taken at the
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* start of the xen_blkif_schedule thread. */
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if (atomic_read(&blkif->refcnt) <= 2)
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break;
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} while (!kthread_should_stop());
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atomic_set(&blkif->drain, 0);
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}
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@ -502,11 +502,11 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
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make_response(pending_req->blkif, pending_req->id,
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pending_req->operation, pending_req->status);
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xen_blkif_put(pending_req->blkif);
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free_req(pending_req);
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if (atomic_read(&pending_req->blkif->refcnt) <= 2) {
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if (atomic_read(&pending_req->blkif->drain))
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complete(&pending_req->blkif->drain_complete);
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}
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free_req(pending_req);
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}
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}
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