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| author |   Jens Axboe <axboe@kernel.dk> | 2017-07-25 15:30:21 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-07-25 15:30:21 -0600 |
| commit | e9193da00fb5624348b420717af798f01f0bfd64 (patch) | |
| tree | 900d620faaa4d6dc0a5513a5dca7d574903fb677 | |
| parent | nbd: clear disconnected on reconnect (diff) | |
| parent | xen/blkfront: always allocate grants first from per-queue persistent grants (diff) | |
| download | linux-dev-e9193da00fb5624348b420717af798f01f0bfd64.tar.xz linux-dev-e9193da00fb5624348b420717af798f01f0bfd64.zip | |
Merge branch 'stable/for-jens-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus
Pull xen-blkfront fixes from Konrad for 4.13.
| -rw-r--r-- | drivers/block/xen-blkfront.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 1799bba74390..98e34e4c62b8 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -708,6 +708,7 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri * existing persistent grants, or if we have to get new grants, * as there are not sufficiently many free. */ + bool new_persistent_gnts = false; struct scatterlist *sg; int num_sg, max_grefs, num_grant; @@ -719,19 +720,21 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri */ max_grefs += INDIRECT_GREFS(max_grefs); - /* - * We have to reserve 'max_grefs' grants because persistent - * grants are shared by all rings. - */ - if (max_grefs > 0) - if (gnttab_alloc_grant_references(max_grefs, &setup.gref_head) < 0) { + /* Check if we have enough persistent grants to allocate a requests */ + if (rinfo->persistent_gnts_c < max_grefs) { + new_persistent_gnts = true; + + if (gnttab_alloc_grant_references( + max_grefs - rinfo->persistent_gnts_c, + &setup.gref_head) < 0) { gnttab_request_free_callback( &rinfo->callback, blkif_restart_queue_callback, rinfo, - max_grefs); + max_grefs - rinfo->persistent_gnts_c); return 1; } + } /* Fill out a communications ring structure. */ id = blkif_ring_get_request(rinfo, req, &ring_req); @@ -832,7 +835,7 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri if (unlikely(require_extra_req)) rinfo->shadow[extra_id].req = *extra_ring_req; - if (max_grefs > 0) + if (new_persistent_gnts) gnttab_free_grant_references(setup.gref_head); return 0; @@ -906,8 +909,8 @@ out_err: return BLK_STS_IOERR; out_busy: - spin_unlock_irqrestore(&rinfo->ring_lock, flags); blk_mq_stop_hw_queue(hctx); + spin_unlock_irqrestore(&rinfo->ring_lock, flags); return BLK_STS_RESOURCE; } |