From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47091) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fHrDI-0006Ti-Al for qemu-devel@nongnu.org; Sun, 13 May 2018 09:39:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fHrDF-0006K2-L0 for qemu-devel@nongnu.org; Sun, 13 May 2018 09:38:58 -0400 MIME-Version: 1.0 References: <1525506577-1946-1-git-send-email-ivanren@tencent.com> In-Reply-To: <1525506577-1946-1-git-send-email-ivanren@tencent.com> From: Ivan Ren Date: Sun, 13 May 2018 21:38:38 +0800 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [Qemu-devel] [PATCH v2] qemu-img: return allocated size for block device with qcow2 format List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: kwolf@redhat.com, mreitz@redhat.com Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org ping for review On Sat, May 5, 2018 at 3:50 PM Ivan Ren wrote: > qemu-img info with a block device which has a qcow2 format always > return 0 for disk size, and this can not reflect the qcow2 size > and the used space of the block device. This patch return the > allocated size of qcow2 as the disk size. > > Signed-off-by: Ivan Ren > --- > block/qcow2.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 54 insertions(+) > > This version differs from the previous: > (1).Accumulate all non-0 refcount cluster as the allocated size instead the > highest offset. > (2).Simplify the implementation by just check the refcount info. > > diff --git a/block/qcow2.c b/block/qcow2.c > index ef68772..e64469a 100644 > --- a/block/qcow2.c > +++ b/block/qcow2.c > @@ -4493,6 +4493,59 @@ static QemuOptsList qcow2_create_opts = { > } > }; > > +/* Get allocated space of qcow2, aligned to cluster_size */ > +static int64_t qcow2_get_allocated_size(BlockDriverState *bs) > +{ > + int64_t allocated_cluster_count = 0; > + uint64_t refcount; > + int64_t i, j, begin_index, end_index; > + > + BDRVQcow2State *s = bs->opaque; > + > + /* Traverse refcount table */ > + for (i = 0; i < s->refcount_table_size; i++) { > + if (s->refcount_table[i] & REFT_OFFSET_MASK) { > + begin_index = i * s->refcount_block_size; > + end_index = begin_index + s->refcount_block_size; > + for (j = begin_index; j < end_index; j++) { > + if (qcow2_get_refcount(bs, j, &refcount) < 0) { > + continue; > + } > + if (refcount > 0) { > + allocated_cluster_count++; > + } > + } > + } > + > + } > + > + return allocated_cluster_count * s->cluster_size; > +} > + > +static int64_t qcow2_get_allocated_file_size(BlockDriverState *bs) > +{ > + int64_t ret = 0; > + > + /* Get through bs->file first */ > + if (bs->file) { > + ret = bdrv_get_allocated_file_size(bs->file->bs); > + } > + > + /* > + * If ret < 0, some error may happen to the underlying media, return > the > + * error directly. > + * If ret == 0, means length get from bs->file is 0, which is > impossible > + * for a normal file because of the qcow2 header. In this case, the > + * underlying media may be a block device or anything else that can't > + * return a suitable size. So we get the allocated size of qcow2 > instead. > + */ > + if (!ret) { > + ret = qcow2_get_allocated_size(bs); > + } > + > + return ret; > +} > + > BlockDriver bdrv_qcow2 = { > .format_name = "qcow2", > .instance_size = sizeof(BDRVQcow2State), > @@ -4516,6 +4569,7 @@ BlockDriver bdrv_qcow2 = { > .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes, > .bdrv_co_pdiscard = qcow2_co_pdiscard, > .bdrv_truncate = qcow2_truncate, > + .bdrv_get_allocated_file_size = qcow2_get_allocated_file_size, > .bdrv_co_pwritev_compressed = qcow2_co_pwritev_compressed, > .bdrv_make_empty = qcow2_make_empty, > > -- > 1.8.3.1 > >