From 4ca94945dd9fd1887136907f7de0f3030f5d60f7 Mon Sep 17 00:00:00 2001 From: Anthony Liguori Date: Fri, 12 Aug 2011 15:38:13 +0200 Subject: [PATCH 05/15] qed: extract qed_start_allocating_write() RH-Author: Anthony Liguori Message-id: <1313163503-2523-6-git-send-email-aliguori@redhat.com> Patchwork-id: 31328 O-Subject: [RHEL6.2 qemu PATCH 05/15] qed: extract qed_start_allocating_write() Bugzilla: 633370 RH-Acked-by: Marcelo Tosatti RH-Acked-by: Kevin Wolf RH-Acked-by: Orit Wasserman RH-Acked-by: Christoph Hellwig From: Stefan Hajnoczi Copy-on-read requests are a form of allocating write and will need to be queued like other allocating writes. This patch extracts the request queuing code for allocating writes so that it can be reused for copy-on-read in a later patch. Signed-off-by: Stefan Hajnoczi Signed-off-by: Anthony Liguori Bugzilla: 633370 --- block/qed.c | 32 ++++++++++++++++++++++++++------ 1 files changed, 26 insertions(+), 6 deletions(-) Signed-off-by: Michal Novotny --- block/qed.c | 32 ++++++++++++++++++++++++++------ 1 files changed, 26 insertions(+), 6 deletions(-) diff --git a/block/qed.c b/block/qed.c index 7f5f1e6..915e0d5 100644 --- a/block/qed.c +++ b/block/qed.c @@ -1090,14 +1090,15 @@ static bool qed_should_set_need_check(BDRVQEDState *s) } /** - * Write new data cluster + * Start an allocating write request or queue it * - * @acb: Write request - * @len: Length in bytes + * @ret: true if request can proceed, false if queued * - * This path is taken when writing to previously unallocated clusters. + * If a request is queued this function returns false and the caller should + * return. When it becomes time for the request to proceed the qed_aio_next() + * function will be called. */ -static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len) +static bool qed_start_allocating_write(QEDAIOCB *acb) { BDRVQEDState *s = acb_to_s(acb); @@ -1112,7 +1113,26 @@ static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len) } if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs) || s->allocating_write_reqs_plugged) { - return; /* wait for existing request to finish */ + return false; + } + return true; +} + +/** + * Write new data cluster + * + * @acb: Write request + * @len: Length in bytes + * + * This path is taken when writing to previously unallocated clusters. + */ +static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len) +{ + BDRVQEDState *s = acb_to_s(acb); + BlockDriverCompletionFunc *cb; + + if (!qed_start_allocating_write(acb)) { + return; } acb->cur_nclusters = qed_bytes_to_clusters(s, -- 1.7.4.4