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2020-04-07qcow2: Check request size in qcow2_co_pwritev_compressed_part()Alberto Garcia
When issuing a compressed write request the number of bytes must be a multiple of the cluster size or reach the end of the last cluster. With the current code such requests are allowed and we hit an assertion: $ qemu-img create -f qcow2 img.qcow2 1M $ qemu-io -c 'write -c 0 32k' img.qcow2 qemu-io: block/qcow2.c:4257: qcow2_co_pwritev_compressed_task: Assertion `bytes == s->cluster_size || (bytes < s->cluster_size && (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS))' failed. Aborted This patch fixes a regression introduced in 0d483dce38 Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200406143401.26854-1-berto@igalia.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-04-07qcow2: Forbid discard in qcow2 v2 images with backing filesAlberto Garcia
A discard request deallocates the selected clusters so they read back as zeroes. This is done by clearing the cluster offset field and setting QCOW_OFLAG_ZERO in the L2 entry. This flag is however only supported when qcow_version >= 3. In older images the cluster is simply deallocated, exposing any possible stale data from the backing file. Since discard is an advisory operation it's safer to simply forbid it in this scenario. Note that we are adding this check to qcow2_co_pdiscard() and not to qcow2_cluster_discard() or discard_in_l2_slice() because the last two are also used by qcow2_snapshot_create() to discard the clusters used by the VM state. In this case there's no risk of exposing stale data to the guest and we really want that the clusters are always discarded. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200331114345.29993-1-berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26qcow2: Avoid feature name extension on small cluster sizeEric Blake
As the feature name table can be quite large (over 9k if all 64 bits of all three feature fields have names; a mere 8 features leaves only 8 bytes for a backing file name in a 512-byte cluster), it is unwise to emit this optional header in images with small cluster sizes. Update iotest 036 to skip running on small cluster sizes; meanwhile, note that iotest 061 never passed on alternative cluster sizes (however, I limited this patch to tests with output affected by adding feature names, rather than auditing for other tests that are not robust to alternative cluster sizes). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200324174233.1622067-4-eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26qcow2: List autoclear bit names in headerEric Blake
The feature table is supposed to advertise the name of all feature bits that we support; however, we forgot to update the table for autoclear bits. While at it, move the table to read-only memory in code, and tweak the qcow2 spec to name the second autoclear bit. Update iotests that are affected by the longer header length. Fixes: 88ddffae Fixes: 93c24936 Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200324174233.1622067-3-eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26qcow2: Comment typo fixesEric Blake
Various trivial typos noticed while working on this file. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200324174233.1622067-2-eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26block: pass BlockDriver reference to the .bdrv_co_createMaxim Levitsky
This will allow the reuse of a single generic .bdrv_co_create implementation for several drivers. No functional changes. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-24block/qcow2: zero data_file child after freeVladimir Sementsov-Ogievskiy
data_file being NULL doesn't seem to be a correct state, but it's better than dead pointer and simpler to debug. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200316060631.30052-3-vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-24block: Avoid memleak on qcow2 image info failureEric Blake
If we fail to get bitmap info, we must not leak the encryption info. Fixes: b8968c875f403 Fixes: Coverity CID 1421894 Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200320183620.1112123-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Tested-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-11block/qcow2: do free crypto_opts in qcow2_close()Pan Nengyuan
'crypto_opts' forgot to free in qcow2_close(), this patch fix the bellow leak stack: Direct leak of 24 byte(s) in 1 object(s) allocated from: #0 0x7f0edd81f970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970) #1 0x7f0edc6d149d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d) #2 0x55d7eaede63d in qobject_input_start_struct /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qobject-input-visitor.c:295 #3 0x55d7eaed78b8 in visit_start_struct /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qapi-visit-core.c:49 #4 0x55d7eaf5140b in visit_type_QCryptoBlockOpenOptions qapi/qapi-visit-crypto.c:290 #5 0x55d7eae43af3 in block_crypto_open_opts_init /mnt/sdb/qemu-new/qemu_test/qemu/block/crypto.c:163 #6 0x55d7eacd2924 in qcow2_update_options_prepare /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1148 #7 0x55d7eacd33f7 in qcow2_update_options /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1232 #8 0x55d7eacd9680 in qcow2_do_open /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1512 #9 0x55d7eacdc55e in qcow2_open_entry /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1792 #10 0x55d7eacdc8fe in qcow2_open /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1819 #11 0x55d7eac3742d in bdrv_open_driver /mnt/sdb/qemu-new/qemu_test/qemu/block.c:1317 #12 0x55d7eac3e990 in bdrv_open_common /mnt/sdb/qemu-new/qemu_test/qemu/block.c:1575 #13 0x55d7eac4442c in bdrv_open_inherit /mnt/sdb/qemu-new/qemu_test/qemu/block.c:3126 #14 0x55d7eac45c3f in bdrv_open /mnt/sdb/qemu-new/qemu_test/qemu/block.c:3219 #15 0x55d7ead8e8a4 in blk_new_open /mnt/sdb/qemu-new/qemu_test/qemu/block/block-backend.c:397 #16 0x55d7eacde74c in qcow2_co_create /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:3534 #17 0x55d7eacdfa6d in qcow2_co_create_opts /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:3668 #18 0x55d7eac1c678 in bdrv_create_co_entry /mnt/sdb/qemu-new/qemu_test/qemu/block.c:485 #19 0x55d7eb0024d2 in coroutine_trampoline /mnt/sdb/qemu-new/qemu_test/qemu/util/coroutine-ucontext.c:115 Reported-by: Euler Robot <euler.robot@huawei.com> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200227012950.12256-2-pannengyuan@huawei.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-11luks: extract qcrypto_block_calculate_payload_offset()Stefan Hajnoczi
The qcow2 .bdrv_measure() code calculates the crypto payload offset. This logic really belongs in crypto/block.c where it can be reused by other image formats. The "luks" block driver will need this same logic in order to implement .bdrv_measure(), so extract the qcrypto_block_calculate_payload_offset() function now. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200221112522.1497712-2-stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-06block/qcow2: Move bitmap reopen into bdrv_reopen_commit_postPeter Krempa
The bitmap code requires writing the 'file' child when the qcow2 driver is reopened in read-write mode. If the 'file' child is being reopened due to a permissions change, the modification is commited yet when qcow2_reopen_commit is called. This means that any attempt to write the 'file' child will end with EBADFD as the original fd was already closed. Moving bitmap reopening to the new callback which is called after permission modifications are commited fixes this as the file descriptor will be replaced with the correct one. The above problem manifests itself when reopening 'qcow2' format layer which uses a 'file-posix' file child which was opened with the 'auto-read-only' property set. Signed-off-by: Peter Krempa <pkrempa@redhat.com> Message-Id: <db118dbafe1955afbc0a18d3dd220931074ce349.1582893284.git.pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-20block: always fill entire LUKS header space with zerosDaniel P. Berrangé
When initializing the LUKS header the size with default encryption parameters will currently be 2068480 bytes. This is rounded up to a multiple of the cluster size, 2081792, with 64k sectors. If the end of the header is not the same as the end of the cluster we fill the extra space with zeros. This was forgetting that not even the space allocated for the header will be fully initialized, as we only write key material for the first key slot. The space left for the other 7 slots is never written to. An optimization to the ref count checking code: commit a5fff8d4b4d928311a5005efa12d0991fe3b66f9 (refs/bisect/bad) Author: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Date: Wed Feb 27 16:14:30 2019 +0300 qcow2-refcount: avoid eating RAM made the assumption that every cluster which was allocated would have at least some data written to it. This was violated by way the LUKS header is only partially written, with much space simply reserved for future use. Depending on the cluster size this problem was masked by the logic which wrote zeros between the end of the LUKS header and the end of the cluster. $ qemu-img create --object secret,id=cluster_encrypt0,data=123456 \ -f qcow2 -o cluster_size=2k,encrypt.iter-time=1,\ encrypt.format=luks,encrypt.key-secret=cluster_encrypt0 \ cluster_size_check.qcow2 100M Formatting 'cluster_size_check.qcow2', fmt=qcow2 size=104857600 encrypt.format=luks encrypt.key-secret=cluster_encrypt0 encrypt.iter-time=1 cluster_size=2048 lazy_refcounts=off refcount_bits=16 $ qemu-img check --object secret,id=cluster_encrypt0,data=redhat \ 'json:{"driver": "qcow2", "encrypt.format": "luks", \ "encrypt.key-secret": "cluster_encrypt0", \ "file.driver": "file", "file.filename": "cluster_size_check.qcow2"}' ERROR: counting reference for region exceeding the end of the file by one cluster or more: offset 0x2000 size 0x1f9000 Leaked cluster 4 refcount=1 reference=0 ...snip... Leaked cluster 130 refcount=1 reference=0 1 errors were found on the image. Data may be corrupted, or further writes to the image may corrupt it. 127 leaked clusters were found on the image. This means waste of disk space, but no harm to data. Image end offset: 268288 The problem only exists when the disk image is entirely empty. Writing data to the disk image payload will solve the problem by causing the end of the file to be extended further. The change fixes it by ensuring that the entire allocated LUKS header region is fully initialized with zeros. The qemu-img check will still fail for any pre-existing disk images created prior to this change, unless at least 1 byte of the payload is written to. Fully writing zeros to the entire LUKS header is a good idea regardless as it ensures that space has been allocated on the host filesystem (or whatever block storage backend is used). Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20200207135520.2669430-1-berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-18qcow2: Fix alignment checks in encrypted imagesAlberto Garcia
I/O requests to encrypted media should be aligned to the sector size used by the underlying encryption method, not to BDRV_SECTOR_SIZE. Fortunately this doesn't break anything at the moment because both existing QCRYPTO_BLOCK_*_SECTOR_SIZE have the same value as BDRV_SECTOR_SIZE. The checks in qcow2_co_preadv_encrypted() are also unnecessary because they are repeated immediately afterwards in qcow2_co_encdec(). Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200213171646.15876-1-berto@igalia.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-06qcow2: Use BDRV_SECTOR_SIZE instead of the hardcoded valueAlberto Garcia
This replaces all remaining instances in the qcow2 code. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-id: b5f74b606c2d9873b12d29acdb7fd498029c4025.1579374329.git.berto@igalia.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-06qcow2: Don't require aligned offsets in qcow2_co_copy_range_from()Alberto Garcia
qemu-img's convert_co_copy_range() operates at the sector level and block_copy() operates at the cluster level so this condition is always true, but it is not necessary to restrict this here, so let's leave it to the driver implementation return an error if there is any. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-id: a4264aaee656910c84161a2965f7a501437379ca.1579374329.git.berto@igalia.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-06qcow2: Tighten cluster_offset alignment assertionsAlberto Garcia
qcow2_alloc_cluster_offset() and qcow2_get_cluster_offset() always return offsets that are cluster-aligned so don't just check that they are sector-aligned. The check in qcow2_co_preadv_task() is also replaced by an assertion for the same reason. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 558ba339965f858bede4c73ce3f50f0c0493597d.1579374329.git.berto@igalia.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-06qcow2: Don't round the L1 table allocation up to the sector sizeAlberto Garcia
The L1 table is read from disk using the byte-based bdrv_pread() and is never accessed beyond its last element, so there's no need to allocate more memory than that. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: b2e27214ec7b03a585931bcf383ee1ac3a641a10.1579374329.git.berto@igalia.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-06qcow2: Use a GString in report_unsupported_feature()Alberto Garcia
This is a bit more efficient than having to allocate and free memory for each item. The default size (60) is enough for all the existing incompatible features or the "Unknown incompatible feature" message. Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 20200115135626.19442-1-berto@igalia.com Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-01-06qcow2: Allow writing compressed data of multiple clustersAndrey Shinkevich
QEMU currently supports writing compressed data of the size equal to one cluster. This patch allows writing QCOW2 compressed data that exceed one cluster. Now, we split buffered data into separate clusters and write them compressed using the block/aio_task API. Suggested-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1575288906-551879-3-git-send-email-andrey.shinkevich@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-12-19qcow2: Move error check of local_err near its assignmentTuguoyi
The local_err check outside of the if block was necessary when it was introduced in commit d1258dd0c87 because it needed to be executed even if qcow2_load_autoloading_dirty_bitmaps() returned false. After some modifications that all required the error check to remain where it is, commit 9c98f145dfb finally moved the qcow2_load_dirty_bitmaps() call into the if block, so now the error check should be there, too. Signed-off-by: Guoyi Tu <tu.guoyi@h3c.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-12-18qcow2: Use offset_into_cluster()Alberto Garcia
There's a couple of places left in the qcow2 code that still do the calculation manually, so let's replace them. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-12-18qcow2: Declare BDRV_REQ_NO_FALLBACK supportedKevin Wolf
In the common case, qcow2_co_pwrite_zeroes() already only modifies metadata case, so we're fine with or without BDRV_REQ_NO_FALLBACK set. The only exception is when using an external data file, where the request is passed down to the block driver of the external data file. We are forwarding the BDRV_REQ_NO_FALLBACK flag there, though, so this is fine, too. Declare the flag supported therefore. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com>
2019-10-28block: Pass truncate exact=true where reasonableMax Reitz
This is a change in behavior, so all instances need a good justification. The comments added here should explain my reasoning. qed already had a comment that suggests it always expected bdrv_truncate()/blk_truncate() to behave as if exact=true were passed (c743849bee7 came eight months before 55b949c8476), so it was simply broken until now. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-8-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> [mreitz: Changed comment in qed.c to explain why a new QED file must be empty, as requested and suggested by Maxim] Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block: Let format drivers pass @exactMax Reitz
When truncating a format node, the @exact parameter is generally handled simply by virtue of the format storing the new size in the image metadata. Such formats do not need to pass on the parameter to their file nodes. There are exceptions, though: - raw and crypto cannot store the image size, and thus must pass on @exact. - When using qcow2 with an external data file, it just makes sense to keep its size in sync with the qcow2 virtual disk (because the external data file is the virtual disk). Therefore, we should pass @exact when truncating it. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-7-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block: Add @exact parameter to bdrv_co_truncate()Max Reitz
We have two drivers (iscsi and file-posix) that (in some cases) return success from their .bdrv_co_truncate() implementation if the block device is larger than the requested offset, but cannot be shrunk. Some callers do not want that behavior, so this patch adds a new parameter that they can use to turn off that behavior. This patch just adds the parameter and lets the block/io.c and block/block-backend.c functions pass it around. All other callers always pass false and none of the implementations evaluate it, so that this patch does not change existing behavior. Future patches take care of that. Suggested-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-5-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block: Do not truncate file node when formattingMax Reitz
There is no reason why the format drivers need to truncate the protocol node when formatting it. When using the old .bdrv_co_create_ops() interface, the file will be created with no size option anyway, which generally gives it a size of 0. (Exceptions are block devices, which cannot be truncated anyway.) When using blockdev-create, the user must have given the file node some size anyway, so there is no reason why we should override that. qed is an exception, it needs the file to start completely empty (as explained by c743849bee7333c7ef256b7e12e34ed6f907064f). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-4-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Add qcow2_check_fix_snapshot_table()Max Reitz
qcow2_check_read_snapshot_table() can perform consistency checks, but it cannot fix everything. Specifically, it cannot allocate new clusters, because that should wait until the refcount structures are known to be consistent (i.e., after qcow2_check_refcounts()). Thus, it cannot call qcow2_write_snapshots(). Do that in qcow2_check_fix_snapshot_table(), which is called after qcow2_check_refcounts(). Currently, there is nothing that would set result->corruptions, so this is a no-op. A follow-up patch will change that. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-10-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Separate qcow2_check_read_snapshot_table()Max Reitz
Reading the snapshot table can fail. That is a problem when we want to repair the image. Therefore, stop reading the snapshot table in qcow2_do_open() in check mode. Instead, add a new function qcow2_check_read_snapshot_table() that reads the snapshot table at a later point. In the future, we want to handle errors here and fix them. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-9-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Write v3-compliant snapshot list on upgradeMax Reitz
qcow2 v3 requires every snapshot table entry to have two extra data fields: The 64-bit VM state size, and the virtual disk size. Both are optional for v2 images, so they may not be present. qcow2_upgrade() therefore should update the snapshot table to ensure all entries have these extra data fields. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1727347 Reported-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-8-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Put qcow2_upgrade() into its own functionMax Reitz
This does not make sense right now, but it will make sense once we need to do more than to just update s->qcow_version. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-7-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Add Error ** to qcow2_read_snapshots()Max Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-4-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-25qcow2: Fix corruption bug in qcow2_detect_metadata_preallocation()Kevin Wolf
qcow2_detect_metadata_preallocation() calls qcow2_get_refcount() which requires s->lock to be taken to protect its accesses to the refcount table and refcount blocks. However, nothing in this code path actually took the lock. This could cause the same cache entry to be used by two requests at the same time, for different tables at different offsets, resulting in image corruption. As it would be preferable to base the detection on consistent data (even though it's just heuristics), let's take the lock not only around the qcow2_get_refcount() calls, but around the whole function. This patch takes the lock in qcow2_co_block_status() earlier and asserts in qcow2_detect_metadata_preallocation() that we hold the lock. Fixes: 69f47505ee66afaa513305de0c1895a224e52c45 Cc: qemu-stable@nongnu.org Reported-by: Michael Weiser <michael.weiser@gmx.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Tested-by: Michael Weiser <michael.weiser@gmx.de> Reviewed-by: Michael Weiser <michael.weiser@gmx.de> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2019-10-17qcow2-bitmap: move bitmap reopen-rw code to qcow2_reopen_commitVladimir Sementsov-Ogievskiy
The only reason I can imagine for this strange code at the very-end of bdrv_reopen_commit is the fact that bs->read_only updated after calling drv->bdrv_reopen_commit in bdrv_reopen_commit. And in the same time, prior to previous commit, qcow2_reopen_bitmaps_rw did a wrong check for being writable, when actually it only need writable file child not self. So, as it's fixed, let's move things to correct place. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Acked-by: Max Reitz <mreitz@redhat.com> Message-id: 20190927122355.7344-10-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/qcow2-bitmap: do not remove bitmaps on reopen-roVladimir Sementsov-Ogievskiy
qcow2_reopen_bitmaps_ro wants to store bitmaps and then mark them all readonly. But the latter don't work, as qcow2_store_persistent_dirty_bitmaps removes bitmaps after storing. It's OK for inactivation but bad idea for reopen-ro. And this leads to the following bug: Assume we have persistent bitmap 'bitmap0'. Create external snapshot bitmap0 is stored and therefore removed Commit snapshot now we have no bitmaps Do some writes from guest (*) they are not marked in bitmap Shutdown Start bitmap0 is loaded as valid, but it is actually broken! It misses writes (*) Incremental backup it will be inconsistent So, let's stop removing bitmaps on reopen-ro. But don't rejoice: reopening bitmaps to rw is broken too, so the whole scenario will not work after this patch and we can't enable corresponding test cases in 260 iotests still. Reopening bitmaps rw will be fixed in the following patches. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190927122355.7344-7-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/qcow2: proper locking on bitmap add/remove pathsVladimir Sementsov-Ogievskiy
qmp_block_dirty_bitmap_add and do_block_dirty_bitmap_remove do acquire aio context since 0a6c86d024c52b. But this is not enough: we also must lock qcow2 mutex when access in-image metadata. Especially it concerns freeing qcow2 clusters. To achieve this, move qcow2_can_store_new_dirty_bitmap and qcow2_remove_persistent_dirty_bitmap to coroutine context. Since we work in coroutines in correct aio context, we don't need context acquiring in blockdev.c anymore, drop it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190920082543.23444-4-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-10block/qcow2: introduce parallel subrequest handling in read and writeVladimir Sementsov-Ogievskiy
It improves performance for fragmented qcow2 images. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190916175324.18478-6-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-10block/qcow2: refactor qcow2_co_pwritev_partVladimir Sementsov-Ogievskiy
Similarly to previous commit, prepare for parallelizing write-loop iterations. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20190916175324.18478-5-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-10block/qcow2: refactor qcow2_co_preadv_partVladimir Sementsov-Ogievskiy
Further patch will run partial requests of iterations of qcow2_co_preadv in parallel for performance reasons. To prepare for this, separate part which may be parallelized into separate function (qcow2_co_preadv_task). While being here, also separate encrypted clusters reading to own function, like it is done for compressed reading. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20190916175324.18478-4-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-16block/qcow2: refactor encryption codeMaxim Levitsky
* Change the qcow2_co_{encrypt|decrypt} to just receive full host and guest offsets and use this function directly instead of calling do_perform_cow_encrypt (which is removed by that patch). * Adjust qcow2_co_encdec to take full host and guest offsets as well. * Document the qcow2_co_{encrypt|decrypt} arguments to prevent the bug fixed in former commit from hopefully happening again. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-id: 20190915203655.21638-3-mlevitsk@redhat.com Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> [mreitz: Let perform_cow() return the error value returned by qcow2_co_encrypt(), as proposed by Vladimir] Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-16block: Use QEMU_IS_ALIGNEDNir Soffer
Replace instances of: (n & (BDRV_SECTOR_SIZE - 1)) == 0 And: (n & ~BDRV_SECTOR_MASK) == 0 With: QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE) Which reveals the intent of the code better, and makes it easier to locate the code checking alignment. Signed-off-by: Nir Soffer <nsoffer@redhat.com> Message-id: 20190827185913.27427-2-nsoffer@redhat.com Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-10qcow2: Fix the calculation of the maximum L2 cache sizeAlberto Garcia
The size of the qcow2 L2 cache defaults to 32 MB, which can be easily larger than the maximum amount of L2 metadata that the image can have. For example: with 64 KB clusters the user would need a qcow2 image with a virtual size of 256 GB in order to have 32 MB of L2 metadata. Because of that, since commit b749562d9822d14ef69c9eaa5f85903010b86c30 we forbid the L2 cache to become larger than the maximum amount of L2 metadata for the image, calculated using this formula: uint64_t max_l2_cache = virtual_disk_size / (s->cluster_size / 8); The problem with this formula is that the result should be rounded up to the cluster size because an L2 table on disk always takes one full cluster. For example, a 1280 MB qcow2 image with 64 KB clusters needs exactly 160 KB of L2 metadata, but we need 192 KB on disk (3 clusters) even if the last 32 KB of those are not going to be used. However QEMU rounds the numbers down and only creates 2 cache tables (128 KB), which is not enough for the image. A quick test doing 4KB random writes on a 1280 MB image gives me around 500 IOPS, while with the correct cache size I get 16K IOPS. Cc: qemu-stable@nongnu.org Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-08-27block/qcow2: implement .bdrv_co_pwritev(_compressed)_partVladimir Sementsov-Ogievskiy
Implement and use new interface to get rid of hd_qiov. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-13-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-13-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-27block/qcow2: implement .bdrv_co_preadv_partVladimir Sementsov-Ogievskiy
Implement and use new interface to get rid of hd_qiov. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-12-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-12-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-27block/qcow2: refactor qcow2_co_preadv to use buffer-based ioVladimir Sementsov-Ogievskiy
Use buffer based io in encrypted case. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-11-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-11-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-19qcow2: Fix .bdrv_has_zero_init()Max Reitz
If a qcow2 file is preallocated, it can no longer guarantee that it initially appears as filled with zeroes. So implement .bdrv_has_zero_init() by checking whether the file is preallocated; if so, forward the call to the underlying storage node, except for when it is encrypted: Encrypted preallocated images always return effectively random data, so .bdrv_has_zero_init() must always return 0 for them. .bdrv_has_zero_init_truncate() can remain bdrv_has_zero_init_1(), because it presupposes PREALLOC_MODE_OFF. Reported-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190724171239.8764-7-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19block: Implement .bdrv_has_zero_init_truncate()Max Reitz
We need to implement .bdrv_has_zero_init_truncate() for every block driver that supports truncation and has a .bdrv_has_zero_init() implementation. Implement it the same way each driver implements .bdrv_has_zero_init(). This is at least not any more unsafe than what we had before. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190724171239.8764-5-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-16Include qemu/main-loop.h lessMarkus Armbruster
In my "build everything" tree, changing qemu/main-loop.h triggers a recompile of some 5600 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). It includes block/aio.h, which in turn includes qemu/event_notifier.h, qemu/notify.h, qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h, qemu/thread.h, qemu/timer.h, and a few more. Include qemu/main-loop.h only where it's needed. Touching it now recompiles only some 1700 objects. For block/aio.h and qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the others, they shrink only slightly. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190812052359.30071-21-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-07-08qcow2: Allow -o compat=v3 during qemu-img amendEric Blake
Commit b76b4f60 allowed '-o compat=v3' as an alias for the less-appealing '-o compat=1.1' for 'qemu-img create' since we want to use the QMP form as much as possible, but forgot to do likewise for qemu-img amend. Also, it doesn't help that '-o help' doesn't list our new preferred spellings. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-02block: include base when checking image chain for block allocationAndrey Shinkevich
This patch is used in the 'block/stream: introduce a bottom node' that is following. Instead of the base node, the caller may pass the node that has the base as its backing image to the function bdrv_is_allocated_above() with a new parameter include_base = true and get rid of the dependency on the base that may change during commit/stream parallel jobs. Now, if the specified base is not found in the backing image chain, the QEMU will abort. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 1559152576-281803-2-git-send-email-andrey.shinkevich@virtuozzo.com [mreitz: Squashed in the following as a rebase on conflicting patches:] Message-id: e3cf99ae-62e9-8b6e-5a06-d3c8b9363b85@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-06-04block: Add BlockBackend.ctxKevin Wolf
This adds a new parameter to blk_new() which requires its callers to declare from which AioContext this BlockBackend is going to be used (or the locks of which AioContext need to be taken anyway). The given context is only stored and kept up to date when changing AioContexts. Actually applying the stored AioContext to the root node is saved for another commit. Signed-off-by: Kevin Wolf <kwolf@redhat.com>