From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39257) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xe6MC-0003cY-2O for qemu-devel@nongnu.org; Tue, 14 Oct 2014 13:58:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xe6M3-00011c-1r for qemu-devel@nongnu.org; Tue, 14 Oct 2014 13:58:00 -0400 Received: from mail-pd0-x235.google.com ([2607:f8b0:400e:c02::235]:40085) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xe6M2-0000zG-QU for qemu-devel@nongnu.org; Tue, 14 Oct 2014 13:57:50 -0400 Received: by mail-pd0-f181.google.com with SMTP id z10so7984791pdj.12 for ; Tue, 14 Oct 2014 10:57:49 -0700 (PDT) Date: Wed, 15 Oct 2014 01:57:46 +0800 From: Jun Li Message-ID: <20141014175745.GB17845@localhost.localdomain> References: <1413176644-11031-1-git-send-email-junmuzi@gmail.com> <1413176644-11031-3-git-send-email-junmuzi@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413176644-11031-3-git-send-email-junmuzi@gmail.com> Subject: Re: [Qemu-devel] [PATCH v3 2/2] qcow2: add update refcount table realization for update_refcount List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, juli@redhat.com, famz@redhat.com, stefanha@redhat.com Please ignore this patch, I have submit v4. thx. On Mon, 10/13 13:04, Jun Li wrote: > When every item of refcount block is NULL, free refcount block and reset the > corresponding item of refcount table with NULL. At the same time, put this > cluster to s->free_cluster_index. > > Signed-off-by: Jun Li > --- > This version adding handle self-describing refcount blocks. > --- > block/qcow2-refcount.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 44 insertions(+) > > diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c > index 2bcaaf9..8594ffd 100644 > --- a/block/qcow2-refcount.c > +++ b/block/qcow2-refcount.c > @@ -28,6 +28,7 @@ > #include "qemu/range.h" > > static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size); > +static int write_reftable_entry(BlockDriverState *bs, int rt_index); > static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, > int64_t offset, int64_t length, > int addend, enum qcow2_discard_type type); > @@ -599,6 +600,49 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, > if (refcount == 0 && s->discard_passthrough[type]) { > update_refcount_discard(bs, cluster_offset, s->cluster_size); > } > + > + unsigned int refcount_table_index; > + refcount_table_index = cluster_index >> (s->cluster_bits - > + REFCOUNT_SHIFT); > + > + uint64_t refcount_block_offset = > + s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; > + > + int64_t self_block_index = refcount_block_offset >> s->cluster_bits; > + int self_block_index2 = (refcount_block_offset >> s->cluster_bits) & > + ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); > + > + /* When refcount block is NULL, update refcount table */ > + if (!be16_to_cpu(refcount_block[0]) || self_block_index2 == 0) { > + int k; > + int refcount_block_entries = s->cluster_size / > + sizeof(refcount_block[0]); > + for (k = 0; k < refcount_block_entries; k++) { > + if (k == self_block_index2) { > + k++; > + } > + > + if (be16_to_cpu(refcount_block[k])) { > + break; > + } > + } > + > + if (k == refcount_block_entries) { > + if (self_block_index < s->free_cluster_index) { > + s->free_cluster_index = self_block_index; > + } > + > + /* update refcount table */ > + s->refcount_table[refcount_table_index] = 0; > + ret = write_reftable_entry(bs, refcount_table_index); > + if (ret < 0) { > + fprintf(stderr, "Could not update refcount table: %s\n", > + strerror(-ret)); > + goto fail; > + } > + > + } > + } > } > > ret = 0; > -- > 1.9.3 >