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[Qemu-devel] [PATCH v4 00/21] Add qemu-img subcommand to dump file metad
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH v4 00/21] Add qemu-img subcommand to dump file metadata |
Date: |
Thu, 29 Aug 2013 16:00:00 +0200 |
This series adds a subcommand to "qemu-img" that can dump file metadata.
Metadata that is dumped includes:
- whether blocks are allocated in bs->file and, if so, where
- whether blocks are zero
- whether data is read from bs or bs->backing_hd
Metadata is dumped for an entire chain of images. One example usage is
(for non-compressed, non-encrypted images) to transform the metadata
into a Linux device-mapper setup, and make a qcow2 image available (for
read only) as a block device. Another possible usage is to determine
the used areas of a file, and convert it in place to another format.
Alternatively, the richer data can be used by block jobs to quickly
determine if a block is zero without reading it.
The patches implement a new operation, bdrv_co_get_block_status, that
supersedes bdrv_co_is_allocated. The bdrv_is_allocated API is still
available of course, and implemented on top of the new operation.
Patches 1-3 touch cow, which uses bdrv_co_is_allocated during its reads
and writes. I optimized it a bit because it was unbearably slow during
testing. With these patches (also tested with blkverify), booting of
a cow guest image is not particularly slow.
Patch 4 fixes the bs->total_sectors file size cache, which is used in
bdrv_co_get_block_status to clamp invalid input.
Patches 5 to 8 clean up the bdrv_is_allocated and bdrv_is_allocated_above
implementation, eliminating some code duplication.
Patches 9 and 10 tweak bdrv_has_zero_init and its usage in qemu-img in
a way that helps when implementing the new API.
Patches 11 to 15 implement bdrv_get_block_status and change the formats
to report all the available information.
Patch 16 and 17 adds the "map" subcommand to qemu-img, and the relevant
documentation.
Finally, patches 18 to 21 tweak the implementation to extract more
information from protocols, and combine this information with format
metadata whenever possible.
v3->v4:
new patch 6 to fix bdrv_co_is_allocated for removable media
new patch 15 replacing custom code in qemu-img
bdrv_is_allocated result checked everywhere
make human-readable format really human-readable
handle (actually ignore) errors in recursive get_block_status call
Paolo Bonzini (21):
cow: make reads go at a decent speed
cow: make writes go at a less indecent speed
cow: do not call bdrv_co_is_allocated
block: keep bs->total_sectors up to date even for growable block
devices
block: make bdrv_co_is_allocated static
block: do not use ->total_sectors in bdrv_co_is_allocated
block: remove bdrv_is_allocated_above/bdrv_co_is_allocated_above
distinction
block: expect errors from bdrv_co_is_allocated
qemu-img: always probe the input image for allocated sectors
block: make bdrv_has_zero_init return false for copy-on-write-images
block: introduce bdrv_get_block_status API
block: define get_block_status return value
block: return get_block_status data and flags for formats
block: use bdrv_has_zero_init to return BDRV_BLOCK_ZERO
block: return BDRV_BLOCK_ZERO past end of backing file
qemu-img: add a "map" subcommand
docs, qapi: document qemu-img map
raw-posix: return get_block_status data and flags
raw-posix: report unwritten extents as zero
block: add default get_block_status implementation for protocols
block: look for zero blocks in bs->file
block.c | 174 +++++++++++++++++++--------------
block/backup.c | 4 ++--
block/commit.c | 6 +-
block/cow.c | 91 +++++++++++++-----
block/mirror.c | 4 +-
block/qcow.c | 13 ++-
block/qcow2.c | 24 +++--
block/qed.c | 39 ++++++--
block/raw-posix.c | 24 +++--
block/raw.c | 6 +-
block/sheepdog.c | 14 +--
block/stream.c | 10 +-
block/vdi.c | 17 +++-
block/vmdk.c | 23 ++++-
block/vvfat.c | 15 +--
include/block/block.h | 34 +++++--
include/block/block_int.h | 2 +-
qapi-schema.json | 29 ++++++
qemu-img-cmds.hx | 6 ++
qemu-img.c | 238 +++++++++++++++++++++++++++++++++++++++++-----
qemu-img.texi | 55 +++++++++++
qemu-io-cmds.c | 4 +
22 files changed, 643 insertions(+), 189 deletions(-)
--
1.8.3.1
- [Qemu-devel] [PATCH v4 00/21] Add qemu-img subcommand to dump file metadata,
Paolo Bonzini <=
- [Qemu-devel] [PATCH v4 01/21] cow: make reads go at a decent speed, Paolo Bonzini, 2013/08/29
- [Qemu-devel] [PATCH v4 02/21] cow: make writes go at a less indecent speed, Paolo Bonzini, 2013/08/29
- [Qemu-devel] [PATCH v4 03/21] cow: do not call bdrv_co_is_allocated, Paolo Bonzini, 2013/08/29
- [Qemu-devel] [PATCH v4 04/21] block: keep bs->total_sectors up to date even for growable block devices, Paolo Bonzini, 2013/08/29
- [Qemu-devel] [PATCH v4 05/21] block: make bdrv_co_is_allocated static, Paolo Bonzini, 2013/08/29
- [Qemu-devel] [PATCH v4 08/21] block: expect errors from bdrv_co_is_allocated, Paolo Bonzini, 2013/08/29