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2019-11-18nbd: Don't send oversize stringsEric Blake
Qemu as server currently won't accept export names larger than 256 bytes, nor create dirty bitmap names longer than 1023 bytes, so most uses of qemu as client or server have no reason to get anywhere near the NBD spec maximum of a 4k limit per string. However, we weren't actually enforcing things, ignoring when the remote side violates the protocol on input, and also having several code paths where we send oversize strings on output (for example, qemu-nbd --description could easily send more than 4k). Tighten things up as follows: client: - Perform bounds check on export name and dirty bitmap request prior to handing it to server - Validate that copied server replies are not too long (ignoring NBD_INFO_* replies that are not copied is not too bad) server: - Perform bounds check on export name and description prior to advertising it to client - Reject client name or metadata query that is too long - Adjust things to allow full 4k name limit rather than previous 256 byte limit Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20191114024635.11363-4-eblake@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-11-18bitmap: Enforce maximum bitmap name lengthEric Blake
We document that for qcow2 persistent bitmaps, the name cannot exceed 1023 bytes. It is inconsistent if transient bitmaps do not have to abide by the same limit, and it is unlikely that any existing client even cares about using bitmap names this long. It's time to codify that ALL bitmaps managed by qemu (whether persistent in qcow2 or not) have a documented maximum length. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20191114024635.11363-3-eblake@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-11-07qcow2: Fix QCOW2_COMPRESSED_SECTOR_MASKMax Reitz
Masks for L2 table entries should have 64 bit. Fixes: b6c246942b14d3e0dec46a6c5868ed84e7dbea19 Buglink: https://bugs.launchpad.net/qemu/+bug/1850000 Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191028161841.1198-2-mreitz@redhat.com Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-07qcow2-bitmap: Fix uint64_t left-shift overflowTuguoyi
There are two issues in In check_constraints_on_bitmap(), 1) The sanity check on the granularity will cause uint64_t integer left-shift overflow when cluster_size is 2M and the granularity is BIGGER than 32K. 2) The way to calculate image size that the maximum bitmap supported can map to is a bit incorrect. This patch fix it by add a helper function to calculate the number of bytes needed by a normal bitmap in image and compare it to the maximum bitmap bytes supported by qemu. Fixes: 5f72826e7fc62167cf3a Signed-off-by: Guoyi Tu <tu.guoyi@h3c.com> Message-id: 4ba40cd1e7ee4a708b40899952e49f22@h3c.com Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-04block/file-posix: Let post-EOF fallocate serializeMax Reitz
The XFS kernel driver has a bug that may cause data corruption for qcow2 images as of qemu commit c8bb23cbdbe32f. We can work around it by treating post-EOF fallocates as serializing up until infinity (INT64_MAX in practice). Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191101152510.11719-4-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-04block: Add bdrv_co_get_self_request()Max Reitz
Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191101152510.11719-3-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-04block: Make wait/mark serialising requests publicMax Reitz
Make both bdrv_mark_request_serialising() and bdrv_wait_serialising_requests() public so they can be used from block drivers. Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191101152510.11719-2-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-04block/block-copy: fix s->copy_size for compressed clusterVladimir Sementsov-Ogievskiy
0e2402452f1f20429 allowed writes larger than cluster, but that's unsupported for compressed write. Fix it. Fixes: 0e2402452f1f20429 Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20191029150934.26416-1-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-10-28' ↵Peter Maydell
into staging Block patches for softfreeze: - iotest patches - Improve performance of the mirror block job in write-blocking mode - Limit memory usage for the backup block job - Add discard and write-zeroes support to the NVMe host block driver - Fix a bug in the mirror job - Prevent the qcow2 driver from creating technically non-compliant qcow2 v3 images (where there is not enough extra data for snapshot table entries) - Allow callers of bdrv_truncate() (etc.) to determine whether the file must be resized to the exact given size or whether it is OK for block devices not to shrink # gpg: Signature made Mon 28 Oct 2019 12:13:53 GMT # gpg: using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40 # gpg: issuer "mreitz@redhat.com" # gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full] # Primary key fingerprint: 91BE B60A 30DB 3E88 57D1 1829 F407 DB00 61D5 CF40 * remotes/maxreitz/tags/pull-block-2019-10-28: (69 commits) qemu-iotests: restrict 264 to qcow2 only Revert "qemu-img: Check post-truncation size" block: Pass truncate exact=true where reasonable block: Let format drivers pass @exact block: Evaluate @exact in protocol drivers block: Add @exact parameter to bdrv_co_truncate() block: Do not truncate file node when formatting block/cor: Drop cor_co_truncate() block: Handle filter truncation like native impl. iotests: Test qcow2's snapshot table handling iotests: Add peek_file* functions qcow2: Fix v3 snapshot table entry compliancy qcow2: Repair snapshot table with too many entries qcow2: Fix overly long snapshot tables qcow2: Keep track of the snapshot table length qcow2: Fix broken snapshot table entries qcow2: Add qcow2_check_fix_snapshot_table() qcow2: Separate qcow2_check_read_snapshot_table() qcow2: Write v3-compliant snapshot list on upgrade qcow2: Put qcow2_upgrade() into its own function ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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: Evaluate @exact in protocol driversMax Reitz
We have two protocol drivers that return success when trying to shrink a block device even though they cannot shrink it. This behavior is now only allowed with exact=false, so they should return an error with exact=true. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-6-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>
2019-10-28block/cor: Drop cor_co_truncate()Max Reitz
No other filter driver has a .bdrv_co_truncate() implementation, and there is no need to because the general block layer code can handle it just as well. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-3-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block: Handle filter truncation like native impl.Max Reitz
Make the filter truncation (passing it through to bs->file) a first-class citizen and handle it exactly as if it was the filter driver's native implementation of .bdrv_co_truncate(). I do not see a reason not to, it makes the code a bit shorter, and may be even more correct because this gets us to finish the write_req that we prepared before (may be important to e.g. bring dirty bitmaps to the correct size). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-2-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Fix v3 snapshot table entry compliancyMax Reitz
qcow2 v3 images require every snapshot table entry to have at least 16 bytes of extra data. If they do not, let qemu-img check -r all fix it. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-15-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Repair snapshot table with too many entriesMax Reitz
The user cannot choose which snapshots are removed. This is fine because we have chosen the maximum snapshot table size to be so large (65536 entries) that it cannot be reasonably reached. If the snapshot table exceeds this size, the image has probably been corrupted in some way; in this case, it is most important to just make the image usable such that the user can copy off at least the active layer. (Also note that the snapshots will be removed only with "-r all", so a plain "check" or "check -r leaks" will not delete any data.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-14-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Fix overly long snapshot tablesMax Reitz
We currently refuse to open qcow2 images with overly long snapshot tables. This patch makes qemu-img check -r all drop all offending entries past what we deem acceptable. The user cannot choose which snapshots are removed. This is fine because we have chosen the maximum snapshot table size to be so large (64 MB) that it cannot be reasonably reached. If the snapshot table exceeds this size, the image has probably been corrupted in some way; in this case, it is most important to just make the image usable such that the user can copy off at least the active layer. (Also note that the snapshots will be removed only with "-r all", so a plain "check" or "check -r leaks" will not delete any data.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-13-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Keep track of the snapshot table lengthMax Reitz
When repairing the snapshot table, we truncate entries that have too much extra data. This frees up space that we do not have to count towards the snapshot table size. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-12-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Fix broken snapshot table entriesMax Reitz
The only case where we currently reject snapshot table entries is when they have too much extra data. Fix them with qemu-img check -r all by counting it as a corruption, reducing their extra_data_size, and then letting qcow2_check_fix_snapshot_table() do the rest. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-11-mreitz@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: Make qcow2_write_snapshots() publicMax Reitz
Updating the snapshot list will be useful when upgrading a v2 image to v3, so we will need to call this function in qcow2.c. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-6-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28qcow2: Keep unknown extra snapshot dataMax Reitz
The qcow2 specification says to ignore unknown extra data fields in snapshot table entries. Currently, we discard it whenever we update the image, which is a bit different from "ignore". This patch makes the qcow2 driver keep all unknown extra data fields when updating an image's snapshot table. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-5-mreitz@redhat.com [mreitz: Adjusted comments as proposed by Eric] 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>
2019-10-28qcow2: Use endof()Max Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-3-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28mirror: Do not dereference invalid pointersMax Reitz
mirror_exit_common() may be called twice (if it is called from mirror_prepare() and fails, it will be called from mirror_abort() again). In such a case, many of the pointers in the MirrorBlockJob object will already be freed. This can be seen most reliably for s->target, which is set to NULL (and then dereferenced by blk_bs()). Cc: qemu-stable@nongnu.org Fixes: 737efc1eda23b904fbe0e66b37715fb0e5c3e58b Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20191014153931.20699-2-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/nvme: add support for discardMaxim Levitsky
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-id: 20190913133627.28450-3-mlevitsk@redhat.com Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/nvme: add support for write zerosMaxim Levitsky
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-id: 20190913133627.28450-2-mlevitsk@redhat.com Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/block-copy: increase buffered copy requestVladimir Sementsov-Ogievskiy
No reason to limit buffered copy to one cluster. Let's allow up to 1 MiB. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191022111805.3432-7-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/block-copy: add memory limitVladimir Sementsov-Ogievskiy
Currently total allocation for parallel requests to block-copy instance is unlimited. Let's limit it to 128 MiB. For now block-copy is used only in backup, so actually we limit total allocation for backup job. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191022111805.3432-6-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/block-copy: refactor copyingVladimir Sementsov-Ogievskiy
Merge copying code into one function block_copy_do_copy, which only calls bdrv_ io functions and don't do any synchronization (like dirty bitmap set/reset). Refactor block_copy() function so that it takes full decision about size of chunk to be copied and does all the synchronization (checking intersecting requests, set/reset dirty bitmaps). It will help: - introduce parallel processing of block_copy iterations: we need to calculate chunk size, start async chunk copying and go to the next iteration - simplify synchronization improvement (like memory limiting in further commit and reducing critical section (now we lock the whole requested range, when actually we need to lock only dirty region which we handle at the moment)) Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191022111805.3432-4-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/block-copy: limit copy_range_size to 16 MiBVladimir Sementsov-Ogievskiy
Large copy range may imply memory allocation and large io effort, so using 2G copy range request may be bad idea. Let's limit it to 16 MiB. It also helps the following patch to refactor copy-with-offload fallback to copy-with-bounce-buffer. Note, that total memory usage of backup is still not limited, it will be fixed in further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191022111805.3432-3-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/block-copy: allocate buffer in block_copy_with_bounce_bufferVladimir Sementsov-Ogievskiy
Move bounce_buffer allocation block_copy_with_bounce_buffer. This commit simplifies further work on implementing copying by larger chunks (of different size) and further asynchronous handling of block_copy iterations (with help of block/aio_task API). Allocation works fast, a lot faster than disk io, so it's not a problem that we now allocate/free bounce_buffer more times. And we anyway will have to allocate several bounce_buffers for parallel execution of loop iterations in future. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191022111805.3432-2-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28Revert "mirror: Only mirror granularity-aligned chunks"Vladimir Sementsov-Ogievskiy
This reverts commit 9adc1cb49af8d4e54f57980b1eed5c0a4b2dafa6. "mirror: Only mirror granularity-aligned chunks" Since previous commit unaligned chunks are supported by do_sync_target_write. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191011090711.19940-6-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/mirror: support unaligned write in active mirrorVladimir Sementsov-Ogievskiy
Prior 9adc1cb49af8d do_sync_target_write had a bug: it reset aligned-up region in the dirty bitmap, which means that we may not copy some bytes and assume them copied, which actually leads to producing corrupted target. So 9adc1cb49af8d forced dirty bitmap granularity to be request_alignment for mirror-top filter, so we are not working with unaligned requests. However forcing large alignment obviously decreases performance of unaligned requests. This commit provides another solution for the problem: if unaligned padding is already dirty, we can safely ignore it, as 1. It's dirty, it will be copied by mirror_iteration anyway 2. It's dirty, so skipping it now we don't increase dirtiness of the bitmap and therefore don't damage "synchronicity" of the write-blocking mirror. If unaligned padding is not dirty, we just write it, no reason to touch dirty bitmap if we succeed (on failure we'll set the whole region ofcourse, but we loss "synchronicity" on failure anyway). Note: we need to disable dirty_bitmap, otherwise we will not be able to see in do_sync_target_write bitmap state before current operation. We may of course check dirty bitmap before the operation in bdrv_mirror_top_do_write and remember it, but we don't need active dirty bitmap for write-blocking mirror anyway. New code-path is unused until the following commit reverts 9adc1cb49af8d. Suggested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20191011090711.19940-5-vsementsov@virtuozzo.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/block-backend: add blk_co_pwritev_partVladimir Sementsov-Ogievskiy
Add blk write function with qiov_offset parameter. It's needed for the following commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191011090711.19940-4-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block/mirror: simplify do_sync_target_writeVladimir Sementsov-Ogievskiy
do_sync_target_write is called from bdrv_mirror_top_do_write after write/discard operation, all inside active_write/active_write_settle protecting us from mirror iteration. So the whole area is dirty for sure, no reason to examine dirty bitmap. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191011090711.19940-3-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-26core: replace getpagesize() with qemu_real_host_page_sizeWei Yang
There are three page size in qemu: real host page size host page size target page size All of them have dedicate variable to represent. For the last two, we use the same form in the whole qemu project, while for the first one we use two forms: qemu_real_host_page_size and getpagesize(). qemu_real_host_page_size is defined to be a replacement of getpagesize(), so let it serve the role. [Note] Not fully tested for some arch or device. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Message-Id: <20191013021145.16011-3-richardw.yang@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@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>
2019-10-25block/backup: drop dead code from backup_job_createVladimir Sementsov-Ogievskiy
After commit 00e30f05de1d195, there is no more "goto error" points after job creation, so after "error:" @job is always NULL and we don't need roll-back job creation. Reported-by: Coverity (CID 1406402) Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-10-22block/nbd: nbd reconnectVladimir Sementsov-Ogievskiy
Implement reconnect. To achieve this: 1. add new modes: connecting-wait: means, that reconnecting is in progress, and there were small number of reconnect attempts, so all requests are waiting for the connection. connecting-nowait: reconnecting is in progress, there were a lot of attempts of reconnect, all requests will return errors. two old modes are used too: connected: normal state quit: exiting after fatal error or on close Possible transitions are: * -> quit connecting-* -> connected connecting-wait -> connecting-nowait (transition is done after reconnect-delay seconds in connecting-wait mode) connected -> connecting-wait 2. Implement reconnect in connection_co. So, in connecting-* mode, connection_co, tries to reconnect unlimited times. 3. Retry nbd queries on channel error, if we are in connecting-wait state. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20191009084158.15614-3-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@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: fix and improve qcow2_reopen_bitmaps_rwVladimir Sementsov-Ogievskiy
- Correct check for write access to file child, and in correct place (only if we want to write). - Support reopen rw -> rw (which will be used in following commit), for example, !bdrv_dirty_bitmap_readonly() is not a corruption if bitmap is marked IN_USE in the image. - Consider unexpected bitmap as a corruption and check other combinations of in-image and in-RAM bitmaps. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190927122355.7344-9-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-bitmap: drop qcow2_reopen_bitmaps_rw_hint()Vladimir Sementsov-Ogievskiy
The function is unused, drop it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190927122355.7344-6-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/qcow2-bitmap: get rid of bdrv_has_changed_persistent_bitmapsVladimir Sementsov-Ogievskiy
Firstly, no reason to optimize failure path. Then, function name is ambiguous: it checks for readonly and similar things, but someone may think that it will ignore normal bitmaps which was just unchanged, and this is in bad relation with the fact that we should drop IN_USE flag for unchanged bitmaps in the image. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190927122355.7344-5-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
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