From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42163) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b83KW-0004mx-14 for qemu-devel@nongnu.org; Wed, 01 Jun 2016 06:24:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b83KS-00015x-7b for qemu-devel@nongnu.org; Wed, 01 Jun 2016 06:24:51 -0400 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2070.6\)) From: zhangzhiming In-Reply-To: <467DE7EB-A927-4100-96FB-736444263B06@meituan.com> Date: Wed, 1 Jun 2016 18:24:22 +0800 Message-Id: <6DA33516-D7FB-44C2-A4B8-01974A3E3B77@meituan.com> References: <8E87729A-E996-4D12-B940-87B77C1D22EC@meituan.com> <574DC0CB.7020707@redhat.com> <467DE7EB-A927-4100-96FB-736444263B06@meituan.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [Qemu-block] [PATCH] qcow2 resize with snapshot List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: Kevin Wolf , lihuiba , qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz hi, here are all changes of my code. thanks for the review! =20 zhangzhiming zhangzhiming02@meituan.com Signed-off-by: zhangzhiming --- block.c | 19 +++++++++++++++++++ block/qcow2-cluster.c | 29 +++++++++++++++++++++++++++++ block/qcow2-snapshot.c | 33 +++++++++++++++++++++++---------- block/qcow2.c | 29 ++++++++++++++++++++--------- block/qcow2.h | 1 + include/block/snapshot.h | 1 + 6 files changed, 93 insertions(+), 19 deletions(-) diff --git a/block.c b/block.c index 18a497f..b6f2004 100644 --- a/block.c +++ b/block.c @@ -2631,6 +2631,25 @@ int bdrv_truncate(BlockDriverState *bs, int64_t = offset) return ret; } =20 +int bdrv_apply_snapshot(BlockDriverState *bs, const char *snapshot_id, + uint64_t snapshot_size) +{ + int ret =3D bdrv_snapshot_goto(bs, snapshot_id); + if (ret < 0) { + return ret; + } + + ret =3D refresh_total_sectors(bs, snapshot_size >> = BDRV_SECTOR_BITS); + if (ret < 0) { + return ret; + } + bdrv_dirty_bitmap_truncate(bs); + if (bs->blk) { + blk_dev_resize_cb(bs->blk); + } + return ret; +} + /** * Length of a allocated file in bytes. Sparse files are counted by = actual * allocated space. Return < 0 if error or unknown. diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 31ecc10..f921fd8 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -31,6 +31,35 @@ #include "block/qcow2.h" #include "trace.h" =20 +int shrink_l1_table(BlockDriverState *bs, int64_t new_l1_size) +{ + BDRVQcow2State *s =3D bs->opaque; + int64_t old_l1_size =3D s->l1_size; + s->l1_size =3D new_l1_size; + int ret =3D qcow2_update_snapshot_refcount(bs, s->l1_table_offset, + s->l1_size, 1); + if (ret < 0) { + return ret; + } + + s->l1_size =3D old_l1_size; + ret =3D qcow2_update_snapshot_refcount(bs, s->l1_table_offset, + s->l1_size, -1); + if (ret < 0) { + return ret; + } + s->l1_size =3D new_l1_size; + + uint32_t be_l1_size =3D cpu_to_be32(s->l1_size); + ret =3D bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader, = l1_size), + &be_l1_size, sizeof(be_l1_size)); + if (ret < 0) { + return ret; + } + + return 0; +} + int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, bool exact_size) { diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index 5f4a17e..1ed0e18 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -477,13 +477,6 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const = char *snapshot_id) } sn =3D &s->snapshots[snapshot_index]; =20 - if (sn->disk_size !=3D bs->total_sectors * BDRV_SECTOR_SIZE) { - error_report("qcow2: Loading snapshots with different disk " - "size is not implemented"); - ret =3D -ENOTSUP; - goto fail; - } - /* * Make sure that the current L1 table is big enough to contain the = whole * L1 table of the snapshot. If the snapshot L1 table is smaller, = the @@ -505,7 +498,7 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const = char *snapshot_id) * Decrease the refcount referenced by the old one only when the L1 * table is overwritten. */ - sn_l1_table =3D g_try_malloc0(cur_l1_bytes); + sn_l1_table =3D g_try_malloc0(sn_l1_bytes); if (cur_l1_bytes && sn_l1_table =3D=3D NULL) { ret =3D -ENOMEM; goto fail; @@ -530,11 +523,28 @@ int qcow2_snapshot_goto(BlockDriverState *bs, = const char *snapshot_id) } =20 ret =3D bdrv_pwrite_sync(bs->file->bs, s->l1_table_offset, = sn_l1_table, - cur_l1_bytes); + sn_l1_bytes); + if (ret < 0) { + goto fail; + } + + /* write updated header.size */ + uint64_t be_disk_size =3D cpu_to_be64(sn->disk_size); + ret =3D bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader, size), + &be_disk_size, sizeof(uint64_t)); if (ret < 0) { goto fail; } =20 + uint32_t be_l1_size =3D cpu_to_be32(sn->l1_size); + ret =3D bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader, = l1_size), + &be_l1_size, sizeof(be_l1_size)); + if (ret < 0) { + goto fail; + } + + s->l1_vm_state_index =3D sn->l1_size; + /* * Decrease refcount of clusters of current L1 table. * @@ -552,7 +562,8 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const = char *snapshot_id) * Now update the in-memory L1 table to be in sync with the on-disk = one. We * need to do this even if updating refcounts failed. */ - for(i =3D 0;i < s->l1_size; i++) { + memset(s->l1_table, 0, s->l1_size * sizeof(uint64_t)); + for (i =3D 0; i < sn->l1_size; i++) { s->l1_table[i] =3D be64_to_cpu(sn_l1_table[i]); } =20 @@ -563,6 +574,7 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const = char *snapshot_id) g_free(sn_l1_table); sn_l1_table =3D NULL; =20 + s->l1_size =3D sn->l1_size; /* * Update QCOW_OFLAG_COPIED in the active L1 table (it may have = changed * when we decreased the refcount of the old snapshot. @@ -675,6 +687,7 @@ int qcow2_snapshot_list(BlockDriverState *bs, = QEMUSnapshotInfo **psn_tab) sn_info->date_sec =3D sn->date_sec; sn_info->date_nsec =3D sn->date_nsec; sn_info->vm_clock_nsec =3D sn->vm_clock_nsec; + sn_info->disk_size =3D sn->disk_size; } *psn_tab =3D sn_tab; return s->nb_snapshots; diff --git a/block/qcow2.c b/block/qcow2.c index 62febfc..58b53e1 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2501,22 +2501,33 @@ static int qcow2_truncate(BlockDriverState *bs, = int64_t offset) return -EINVAL; } =20 - /* cannot proceed if image has snapshots */ - if (s->nb_snapshots) { - error_report("Can't resize an image which has snapshots"); + bool v3_truncate =3D (s->qcow_version =3D=3D 3); + + /* cannot proceed if image has snapshots and qcow_version is not 3 = */ + if (!v3_truncate && s->nb_snapshots) { + error_report("Can't resize an image which has snapshots and " + "qcow_version is not 3"); return -ENOTSUP; } =20 - /* shrinking is currently not supported */ - if (offset < bs->total_sectors * 512) { - error_report("qcow2 doesn't support shrinking images yet"); + /* shrinking is supported from version 3 */ + if (!v3_truncate && offset < bs->total_sectors * 512) { + error_report("qcow2 doesn't support shrinking images yet while" + " qcow_version is not 3"); return -ENOTSUP; } =20 new_l1_size =3D size_to_l1(s, offset); - ret =3D qcow2_grow_l1_table(bs, new_l1_size, true); - if (ret < 0) { - return ret; + if (offset < bs->total_sectors * 512) { + ret =3D shrink_l1_table(bs, new_l1_size); + if (ret < 0) { + return ret; + } + } else { + ret =3D qcow2_grow_l1_table(bs, new_l1_size, true); + if (ret < 0) { + return ret; + } } =20 /* write updated header.size */ diff --git a/block/qcow2.h b/block/qcow2.h index a063a3c..dab9e48 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -534,6 +534,7 @@ int qcow2_change_refcount_order(BlockDriverState = *bs, int refcount_order, void *cb_opaque, Error **errp); =20 /* qcow2-cluster.c functions */ +int shrink_l1_table(BlockDriverState *bs, int64_t new_l1_size); int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, bool exact_size); int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index); diff --git a/include/block/snapshot.h b/include/block/snapshot.h index e5c0553..7279c12 100644 --- a/include/block/snapshot.h +++ b/include/block/snapshot.h @@ -44,6 +44,7 @@ typedef struct QEMUSnapshotInfo { uint32_t date_sec; /* UTC date of the snapshot */ uint32_t date_nsec; uint64_t vm_clock_nsec; /* VM clock relative to boot */ + uint64_t disk_size; } QEMUSnapshotInfo; =20 int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info, --=20 1.7.1 > On Jun 1, 2016, at 12:15 PM, zhangzhiming = wrote: >=20 > hi, thanks for the review and the format of code changed. > have a good day! >=20 > zhangzhiming > zhangzhiming02@meituan.com >=20 > Signed-off-by: zhangzhiming > > --- > block.c | 4 ++-- > block/qcow2-cluster.c | 4 ++-- > block/qcow2-snapshot.c | 5 ++--- > block/qcow2.c | 4 ++-- > 4 files changed, 8 insertions(+), 9 deletions(-) >=20 > diff --git a/block.c b/block.c > index 729f820..b6f2004 100644 > --- a/block.c > +++ b/block.c > @@ -2643,9 +2643,9 @@ int bdrv_apply_snapshot(BlockDriverState *bs, = const char *snapshot_id, > if (ret < 0) { > return ret; > } > - bdrv_dirty_bitmap_truncate(bs); /* void return */ > + bdrv_dirty_bitmap_truncate(bs); > if (bs->blk) { > - blk_dev_resize_cb(bs->blk); /* void return too */ > + blk_dev_resize_cb(bs->blk); > } > return ret; > } > diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c > index e4c5c05..f921fd8 100644 > --- a/block/qcow2-cluster.c > +++ b/block/qcow2-cluster.c > @@ -37,14 +37,14 @@ int shrink_l1_table(BlockDriverState *bs, int64_t = new_l1_size) > int64_t old_l1_size =3D s->l1_size; > s->l1_size =3D new_l1_size; > int ret =3D qcow2_update_snapshot_refcount(bs, = s->l1_table_offset, > - s->l1_size, 1); > + s->l1_size, 1); > if (ret < 0) { > return ret; > } > =20 > s->l1_size =3D old_l1_size; > ret =3D qcow2_update_snapshot_refcount(bs, s->l1_table_offset, > - s->l1_size, -1); > + s->l1_size, -1); > if (ret < 0) { > return ret; > } > diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c > index 9c77096..1ed0e18 100644 > --- a/block/qcow2-snapshot.c > +++ b/block/qcow2-snapshot.c > @@ -562,12 +562,11 @@ int qcow2_snapshot_goto(BlockDriverState *bs, = const char *snapshot_id) > * Now update the in-memory L1 table to be in sync with the = on-disk one. We > * need to do this even if updating refcounts failed. > */ > - memset(s->l1_table, 0, s->l1_size*sizeof(uint64_t)); > - for(i =3D 0;i < sn->l1_size; i++) { > + memset(s->l1_table, 0, s->l1_size * sizeof(uint64_t)); > + for (i =3D 0; i < sn->l1_size; i++) { > s->l1_table[i] =3D be64_to_cpu(sn_l1_table[i]); > } > =20 > - > if (ret < 0) { > goto fail; > } > diff --git a/block/qcow2.c b/block/qcow2.c > index 70ec890..58b53e1 100644 > --- a/block/qcow2.c > +++ b/block/qcow2.c > @@ -2503,14 +2503,14 @@ static int qcow2_truncate(BlockDriverState = *bs, int64_t offset) > =20 > bool v3_truncate =3D (s->qcow_version =3D=3D 3); > =20 > - /* cannot proceed if image has snapshots and qcow_version is not = 3*/ > + /* cannot proceed if image has snapshots and qcow_version is not = 3 */ > if (!v3_truncate && s->nb_snapshots) { > error_report("Can't resize an image which has snapshots and " > "qcow_version is not 3"); > return -ENOTSUP; > } > =20 > - /* shrinking is supported from version 3*/ > + /* shrinking is supported from version 3 */ > if (!v3_truncate && offset < bs->total_sectors * 512) { > error_report("qcow2 doesn't support shrinking images yet = while" > " qcow_version is not 3"); > --=20 > 1.7.1 >=20 >=20 >> On Jun 1, 2016, at 12:50 AM, Eric Blake > wrote: >>=20 >> On 05/27/2016 02:14 AM, zhangzhiming wrote: >>> Hi, i modified my code for qcow2 resize, and delete some code = related to=20 >>> qemu monitor. >>>=20 >>> and thanks for the review. >>>=20 >>> zhangzhiming >>> zhangzhiming02@meituan.com = > >>=20 >> Still missing a Signed-off-by designation, so it can't be applied = as-is. >>=20 >>>=20 >>> --- >>> block.c | 19 +++++++++++++++++++ >>> block/qcow2-cluster.c | 29 +++++++++++++++++++++++++++++ >>> block/qcow2-snapshot.c | 34 ++++++++++++++++++++++++---------- >>> block/qcow2.c | 29 ++++++++++++++++++++--------- >>> block/qcow2.h | 1 + >>> include/block/snapshot.h | 1 + >>> 6 files changed, 94 insertions(+), 19 deletions(-) >>>=20 >>> diff --git a/block.c b/block.c >>> index 18a497f..729f820 100644 >>> --- a/block.c >>> +++ b/block.c >>> @@ -2631,6 +2631,25 @@ int bdrv_truncate(BlockDriverState *bs, = int64_t offset) >>> return ret; >>> } >>>=20 >>> +int bdrv_apply_snapshot(BlockDriverState *bs, const char = *snapshot_id, >>> + uint64_t snapshot_size) >>> +{ >>> + int ret =3D bdrv_snapshot_goto(bs, snapshot_id); >>> + if (ret < 0) { >>> + return ret; >>> + } >>> + >>> + ret =3D refresh_total_sectors(bs, snapshot_size >> = BDRV_SECTOR_BITS); >>> + if (ret < 0) { >>> + return ret; >>> + } >>> + bdrv_dirty_bitmap_truncate(bs); /* void return */ >>> + if (bs->blk) { >>> + blk_dev_resize_cb(bs->blk); /* void return too */ >>=20 >> The comments don't add anything here. >>=20 >>> + } >>> + return ret; >>> +} >>> + >>> /** >>> * Length of a allocated file in bytes. Sparse files are counted by = actual >>> * allocated space. Return < 0 if error or unknown. >>> diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c >>> index 31ecc10..e4c5c05 100644 >>> --- a/block/qcow2-cluster.c >>> +++ b/block/qcow2-cluster.c >>> @@ -31,6 +31,35 @@ >>> #include "block/qcow2.h" >>> #include "trace.h" >>>=20 >>> +int shrink_l1_table(BlockDriverState *bs, int64_t new_l1_size) >>> +{ >>> + BDRVQcow2State *s =3D bs->opaque; >>> + int64_t old_l1_size =3D s->l1_size; >>> + s->l1_size =3D new_l1_size; >>> + int ret =3D qcow2_update_snapshot_refcount(bs, = s->l1_table_offset, >>> + s->l1_size, = 1); >>=20 >> Indentation is off. >>=20 >>> + if (ret < 0) { >>> + return ret; >>> + } >>> + >>> + s->l1_size =3D old_l1_size; >>> + ret =3D qcow2_update_snapshot_refcount(bs, s->l1_table_offset, >>> + s->l1_size, = -1); >>=20 >> and again. >>=20 >>> + if (ret < 0) { >>> + return ret; >>> + } >>> + s->l1_size =3D new_l1_size; >>> + >>=20 >>> +++ b/block/qcow2-snapshot.c >>=20 >>> @@ -552,10 +562,12 @@ int qcow2_snapshot_goto(BlockDriverState *bs, = const char *snapshot_id) >>> * Now update the in-memory L1 table to be in sync with the = on-disk one. We >>> * need to do this even if updating refcounts failed. >>> */ >>> - for(i =3D 0;i < s->l1_size; i++) { >>> + memset(s->l1_table, 0, s->l1_size*sizeof(uint64_t)); >>> + for(i =3D 0;i < sn->l1_size; i++) { >>=20 >> As long as you are touching this, use the preferred spacing: >>=20 >> for (i =3D 0; i < sn->l1_size; i++) { >>=20 >>> s->l1_table[i] =3D be64_to_cpu(sn_l1_table[i]); >>> } >>>=20 >>> + >>> if (ret < 0) { >>=20 >> Why the added blank line? >>=20 >>=20 >>> +++ b/block/qcow2.c >>> @@ -2501,22 +2501,33 @@ static int qcow2_truncate(BlockDriverState = *bs, int64_t offset) >>> return -EINVAL; >>> } >>>=20 >>> - /* cannot proceed if image has snapshots */ >>> - if (s->nb_snapshots) { >>> - error_report("Can't resize an image which has snapshots"); >>> + bool v3_truncate =3D (s->qcow_version =3D=3D 3); >>> + >>> + /* cannot proceed if image has snapshots and qcow_version is = not 3*/ >>=20 >> Space before */ >>=20 >>> + if (!v3_truncate && s->nb_snapshots) { >>> + error_report("Can't resize an image which has snapshots and = " >>> + "qcow_version is not 3"); >>> return -ENOTSUP; >>> } >>>=20 >>> - /* shrinking is currently not supported */ >>> - if (offset < bs->total_sectors * 512) { >>> - error_report("qcow2 doesn't support shrinking images yet"); >>> + /* shrinking is supported from version 3*/ >>=20 >> and again >>=20 >>> + if (!v3_truncate && offset < bs->total_sectors * 512) { >>> + error_report("qcow2 doesn't support shrinking images yet = while" >>> + " qcow_version is not 3"); >>> return -ENOTSUP; >>> } >>=20 >>=20 >> --=20 >> Eric Blake eblake redhat com +1-919-301-3266 >> Libvirt virtualization library http://libvirt.org = >>=20 >=20