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2019-04-30block/qed: add missed coroutine_fn markersVladimir Sementsov-Ogievskiy
qed_read_table and qed_write_table use coroutine-only interfaces but are not marked coroutine_fn. Happily, they are called only from coroutine context, so we only need to add missed markers. Reported-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30commit: Make base read-only if there is an early failureAlberto Garcia
You can reproduce this by passing an invalid filter-node-name (like "1234") to block-commit. In this case the base image is put in read-write mode but is never reset back to read-only. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block/stream: use buffer-based ioVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block/commit: use buffer-based ioVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block/backup: use buffer-based ioVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block/parallels: use buffer-based ioVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block/qed: use buffer-based ioVladimir Sementsov-Ogievskiy
Move to _co_ versions of io functions qed_read_table() and qed_write_table(), as we use qemu_co_mutex_unlock() anyway. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block/qcow: use buffer-based ioVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block/qcow2: use buffer-based ioVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30qcow2: Fix error handling in the compression codeAlberto Garcia
This patch fixes a few things in the way error codes are handled in the qcow2 compression code: a) qcow2_co_pwritev_compressed() expects qcow2_co_compress() to only return -1 or -2 on failure, but this is not correct. Since the change from qcow2_compress() to qcow2_co_compress() in commit ceb029cd6feccf9f7607 the new code can also return -EINVAL (although there does not seem to exist any code path that would cause that error in the current implementation). b) -1 and -2 are ad-hoc error codes defined in qcow2_compress(). This patch replaces them with standard constants from errno.h. c) Both qcow2_compress() and qcow2_co_do_compress() return a negative value on failure, but qcow2_co_pwritev_compressed() stores the value in an unsigned data type. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30qcow2: Fix qcow2_make_empty() with external data fileKevin Wolf
make_completely_empty() is an optimisated path for bdrv_make_empty() where completely new metadata is created inside the image file instead of going through all clusters and discarding them. For an external data file, however, we actually need to do discard operations on the data file; just overwriting the qcow2 file doesn't get rid of the data. The necessary slow path with an explicit discard operation already exists for other cases. Use it for external data files, too. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-04-30qcow2: Fix full preallocation with external data fileKevin Wolf
preallocate_co() already gave the data file the full size without forwarding the requested preallocation mode to the protocol. When bdrv_co_truncate() was called later with the preallocation mode, the file didn't actually grow any more, so the data file stayed unallocated even if full preallocation was requested. Pass the right preallocation mode to preallocate_co() and remove the second bdrv_co_truncate() to fix this. As a side effect, the ugly one-byte write in preallocate_co() is replaced with a truncate call, now leaving the last block unallocated on the protocol level as it should be. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-04-30qcow2: Add errp to preallocate_co()Kevin Wolf
We'll add a bdrv_co_truncate() call in the next patch which can return an Error that we don't want to discard. So add an errp parameter to preallocate_co(). Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-04-30qcow2: Avoid COW during metadata preallocationKevin Wolf
Limiting the allocation to INT_MAX bytes isn't particularly clever because it means that the final cluster will be a partial cluster which will be completed through a COW operation. This results in unnecessary data read and write requests which lead to an unwanted non-sparse filesystem block for metadata preallocation. Align the maximum allocation size down to the cluster size to avoid this situation. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-04-30qemu-img: Saner printing of large file sizesEric Blake
Disk sizes close to INT64_MAX cause overflow, for some pretty ridiculous output: $ ./nbdkit -U - memory size=$((2**63 - 512)) --run 'qemu-img info $nbd' image: nbd+unix://?socket=/tmp/nbdkitHSAzNz/socket file format: raw virtual size: -8388607T (9223372036854775296 bytes) disk size: unavailable But there's no reason to have two separate implementations of integer to human-readable abbreviation, where one has overflow and stops at 'T', while the other avoids overflow and goes all the way to 'E'. With this patch, the output now claims 8EiB instead of -8388607T, which really is the correct rounding of largest file size supported by qemu (we could go 511 bytes larger if we used byte-accurate sizing instead of rounding up to the next sector boundary, but that wouldn't change the human-readable result). Quite a few iotests need updates to expected output to match. Reported-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Tested-by: Max Reitz <mreitz@redhat.com>
2019-04-30block/vhdx: Use IEC binary prefixes for size constantsStefano Garzarella
Using IEC binary prefixes in order to make the code more readable, with the exception of DEFAULT_LOG_SIZE because it's passed to stringify(). Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block/vhdx: Remove redundant IEC binary prefixes definitionStefano Garzarella
IEC binary prefixes are already defined in "qemu/units.h", so we can remove redundant definitions in "block/vhdx.h". Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30vmdk: Set vmdk parent backing_format to vmdkSam Eiderman
Commit b69864e5a ("vmdk: Support version=3 in VMDK descriptor files") fixed the probe function to correctly guess vmdk descriptors with version=3. This solves the issue where vmdk snapshot with parent vmdk descriptor containing "version=3" would be treated as raw instead vmdk. In the future case where a new vmdk version is introduced, we will again experience this issue, even if the user will provide "-f vmdk" it will only apply to the tip image and not to the underlying "misprobed" parent image. The code in vmdk.c already assumes that the backing file of vmdk must be vmdk (see vmdk_is_cid_valid which returns 0 if backing file is not vmdk). So let's make it official by supplying the backing_format as vmdk. Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-By: Liran Alon <liran.alon@oracle.com> Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com> Signed-off-by: Shmuel Eiderman <shmuel.eiderman@oracle.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <fam@euphon.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30vpc: unlock Coroutine lock to make IO submit ConcurrentlyZhengui li
Concurrent IO becomes serial IO because of the qemu Coroutine lock, which reduce IO performance severely. So unlock Coroutine lock before bdrv_co_pwritev and bdrv_co_preadv to fix it. Signed-off-by: Zhengui li <lizhengui@huawei.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-18block/qapi: Clean up how we print to monitor or stdoutMarkus Armbruster
bdrv_snapshot_dump(), bdrv_image_info_specific_dump(), bdrv_image_info_dump() and their helpers take an fprintf()-like callback and a FILE * to pass to it. hmp.c passes monitor_printf() cast to fprintf_function and the current monitor cast to FILE *. qemu-img.c and qemu-io-cmds.c pass fprintf and stdout. The type-punning is technically undefined behaviour, but works in practice. Clean up: drop the callback, and call qemu_printf() instead. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20190417191805.28198-8-armbru@redhat.com>
2019-04-17block/ssh: Do not report read/write/flush errors to the userMarkus Armbruster
Callbacks ssh_co_readv(), ssh_co_writev(), ssh_co_flush() report errors to the user with error_printf(). They shouldn't, it's their caller's job. Replace by a suitable trace point. While there, drop the unreachable !s->sftp case. Perhaps we should convert this part of the block driver interface to Error, so block drivers can pass more detail to their callers. Not today. Cc: "Richard W.M. Jones" <rjones@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Max Reitz <mreitz@redhat.com> Cc: qemu-block@nongnu.org Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20190417190641.26814-3-armbru@redhat.com>
2019-04-16qcow2: Fix preallocation bdrv_pwrite to wrong fileKevin Wolf
With an external data file, preallocate_co() must write the final byte to the external data file, not to the qcow2 image file. This is harmless for preallocation of newly created images (only the qcow2 file size is increased to the virtual disk size while it should be much smaller), but with preallocated resize, it could in theory cause visible corruption if the metadata of the image is larger than the data (e.g. lots of bitmaps). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-04-02block: freeze the backing chain earlier in stream_start()Alberto Garcia
Commit 6585493369819a48d34a86d57ec6b97cb5cd9bc0 added code to freeze the backing chain from 'top' to 'base' for the duration of the block-stream job. The problem is that the freezing happens too late in stream_start(): during the bdrv_reopen_set_read_only() call earlier in that function another job can jump in and remove the base image. If that happens we have an invalid chain and QEMU crashes. This patch puts the bdrv_freeze_backing_chain() call at the beginning of the function. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-02block/file-posix: do not fail on unlock bytesVladimir Sementsov-Ogievskiy
bdrv_replace_child() calls bdrv_check_perm() with error_abort on loosening permissions. However file-locking operations may fail even in this case, for example on NFS. And this leads to Qemu crash. Let's avoid such errors. Note, that we ignore such things anyway on permission update commit and abort. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-02block/gluster: limit the transfer size to 512 MiBStefano Garzarella
Several versions of GlusterFS (3.12? -> 6.0.1) fail when the transfer size is greater or equal to 1024 MiB, so we are limiting the transfer size to 512 MiB to avoid this rare issue. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1691320 Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Niels de Vos <ndevos@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-01nbd/client: Trace server noncompliance on structured readsEric Blake
Just as we recently added a trace for a server sending block status that doesn't match the server's advertised minimum block alignment, let's do the same for read chunks. But since qemu 3.1 is such a server (because it advertised 512-byte alignment, but when serving a file that ends in data but is not sector-aligned, NBD_CMD_READ would detect a mid-sector change between data and hole at EOF and the resulting read chunks are unaligned), we don't want to change our behavior of otherwise tolerating unaligned reads. Note that even though we fixed the server for 4.0 to advertise an actual block alignment (which gets rid of the unaligned reads at EOF for posix files), we can still trigger it via other means: $ qemu-nbd --image-opts driver=blkdebug,align=512,image.driver=file,image.filename=/path/to/non-aligned-file Arguably, that is a bug in the blkdebug block status function, for leaking a block status that is not aligned. It may also be possible to observe issues with a backing layer with smaller alignment than the active layer, although so far I have been unable to write a reliable iotest for that scenario. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190330165349.32256-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-04-01block: Add bdrv_get_request_alignment()Eric Blake
The next patch needs access to a device's minimum permitted alignment, since NBD wants to advertise this to clients. Add an accessor function, borrowing from blk_get_max_transfer() for accessing a backend's block limits. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20190329042750.14704-6-eblake@redhat.com>
2019-04-01nbd/client: Support qemu-img convert from unaligned sizeEric Blake
If an NBD server advertises a size that is not a multiple of a sector, the block layer rounds up that size, even though we set info.size to the exact byte value sent by the server. The block layer then proceeds to let us read or query block status on the hole that it added past EOF, which the NBD server is unlikely to be happy with. Fortunately, qemu as a server never advertizes an unaligned size, so we generally don't run into this problem; but the nbdkit server makes it easy to test: $ printf %1000d 1 > f1 $ ~/nbdkit/nbdkit -fv file f1 & pid=$! $ qemu-img convert -f raw nbd://localhost:10809 f2 $ kill $pid $ qemu-img compare f1 f2 Pre-patch, the server attempts a 1024-byte read, which nbdkit rightfully rejects as going beyond its advertised 1000 byte size; the conversion fails and the output files differ (not even the first sector is copied, because qemu-img does not follow ddrescue's habit of trying smaller reads to get as much information as possible in spite of errors). Post-patch, the client's attempts to read (and query block status, for new enough nbdkit) are properly truncated to the server's length, with sane handling of the hole the block layer forced on us. Although f2 ends up as a larger file (1024 bytes instead of 1000), qemu-img compare shows the two images to have identical contents for display to the guest. I didn't add iotests coverage since I didn't want to add a dependency on nbdkit in iotests. I also did NOT patch write, trim, or write zeroes - these commands continue to fail (usually with ENOSPC, but whatever the server chose), because we really can't write to the end of the file, and because 'qemu-img convert' is the most common case where we care about being tolerant (which is read-only). Perhaps we could truncate the request if the client is writing zeros to the tail, but that seems like more work, especially if the block layer is fixed in 4.1 to track byte-accurate sizing (in which case this patch would be reverted as unnecessary). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190329042750.14704-5-eblake@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com>
2019-03-30nbd/client: Report offsets in bdrv_block_statusEric Blake
It is desirable for 'qemu-img map' to have the same output for a file whether it is served over file or nbd protocols. However, ever since we implemented block status for NBD (2.12), the NBD protocol forgot to inform the block layer that as the final layer in the chain, the offset is valid; without an offset, the human-readable form of qemu-img map gives up with the unhelpful: $ nbdkit -U - data data="1" size=512 --run 'qemu-img map $nbd' Offset Length Mapped to File qemu-img: File contains external, encrypted or compressed clusters. The --output=json form always works, because it is reporting the lower-level bdrv_block_status results directly rather than trying to filter out sparse ranges for human consumption - but now it also shows the offset member. With this patch, the human output changes to: Offset Length Mapped to File 0 0x200 0 nbd+unix://?socket=/tmp/nbdkitOxeoLa/socket This change is observable to several iotests. Fixes: 78a33ab5 Reported-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190329042750.14704-4-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-03-30nbd/client: Lower min_block for block-status, unaligned sizeEric Blake
We have a latent bug in our NBD client code, tickled by the brand new nbdkit 1.11.10 block status support: $ nbdkit --filter=log --filter=truncate -U - \ data data="1" size=511 truncate=64K logfile=/dev/stdout \ --run 'qemu-img convert $nbd /var/tmp/out' ... qemu-img: block/io.c:2122: bdrv_co_block_status: Assertion `*pnum && QEMU_IS_ALIGNED(*pnum, align) && align > offset - aligned_offset' failed. The culprit? Our implementation of .bdrv_co_block_status can return unaligned block status for any server that operates with a lower actual alignment than what we tell the block layer in request_alignment, in violation of the block layer's constraints. To date, we've been unable to trip the bug, because qemu as NBD server always advertises block sizing (at which point it is a server bug if the server sends unaligned status - although qemu 3.1 is such a server and I've sent separate patches for 4.0 both to get the server to obey the spec, and to let the client to tolerate server oddities at EOF). But nbdkit does not (yet) advertise block sizing, and therefore is not in violation of the spec for returning block status at whatever boundaries it wants, and those unaligned results can occur anywhere rather than just at EOF. While we are still wise to avoid sending sub-sector read/write requests to a server of unknown origin, we MUST consider that a server telling us block status without an advertised block size is correct. So, we either have to munge unaligned answers from the server into aligned ones that we hand back to the block layer, or we have to tell the block layer about a smaller alignment. Similarly, if the server advertises an image size that is not sector-aligned, we might as well assume that the server intends to let us access those tail bytes, and therefore supports a minimum block size of 1, regardless of whether the server supports block status (although we still need more patches to fix the problem that with an unaligned image, we can send read or block status requests that exceed EOF to the server). Again, qemu as server cannot trip this problem (because it rounds images to sector alignment), but nbdkit advertised unaligned size even before it gained block status support. Solve both alignment problems at once by using better heuristics on what alignment to report to the block layer when the server did not give us something to work with. Note that very few NBD servers implement block status (to date, only qemu and nbdkit are known to do so); and as the NBD spec mentioned block sizing constraints prior to documenting block status, it can be assumed that any future implementations of block status are aware that they must advertise block size if they want a minimum size other than 1. We've had a long history of struggles with picking the right alignment to use in the block layer, as evidenced by the commit message of fd8d372d (v2.12) that introduced the current choice of forced 512-byte alignment. There is no iotest coverage for this fix, because qemu can't provoke it, and I didn't want to make test 241 dependent on nbdkit. Fixes: fd8d372d Reported-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190329042750.14704-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Tested-by: Richard W.M. Jones <rjones@redhat.com>
2019-03-30nbd-client: Work around server BLOCK_STATUS misalignment at EOFEric Blake
The NBD spec is clear that a server that advertises a minimum block size should reply to NBD_CMD_BLOCK_STATUS with extents aligned accordingly. However, we know that the qemu NBD server implementation has had a corner-case bug where it is not compliant with the spec, present since the introduction of NBD_CMD_BLOCK_STATUS in qemu 2.12 (and unlikely to be patched in time for 4.0). Namely, when qemu is serving a file that is not a multiple of 512 bytes, it rounds the size advertised over NBD up to the next sector boundary (someday, I'd like to fix that to be byte-accurate, but it's a much bigger audit not appropriate for this release); yet if the final sector contains data prior to EOF, lseek(SEEK_HOLE) will point to the implicit hole mid-sector which qemu then reported over NBD. We are well within our rights to hang up on a server that can't follow the spec, but it is more useful to try and keep the connection alive in spite of the problem. Do so by tracing a message about the problem, and then either truncating the request back to an aligned boundary (if it covered more than the final sector) or widening it out to the full boundary with a forced status of data (since truncating would result in 0 bytes, but we have to make progress, and valid since data is a default-safe answer). And in practice, since the problem only happens on a sector that starts with data and ends with a hole, we are going to want to read that full sector anyway (where qemu as the server fills in the tail beyond EOF with appropriate NUL bytes). Easy reproduction: $ printf %1000d 1 > file $ qemu-nbd -f raw -t file & pid=$! $ qemu-img map --output=json -f raw nbd://localhost:10809 qemu-img: Could not read file metadata: Invalid argument $ kill $pid where the patched version instead succeeds with: [{ "start": 0, "length": 1024, "depth": 0, "zero": false, "data": true}] Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190326171317.4036-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-03-30nbd: Permit simple error to NBD_CMD_BLOCK_STATUSEric Blake
The NBD spec is clear that when structured replies are active, a simple error reply is acceptable to any command except for NBD_CMD_READ. However, we were mistakenly requiring structured errors for NBD_CMD_BLOCK_STATUS, and hanging up on a server that gave a simple error (since qemu does not behave as such a server, we didn't notice the problem until now). Broken since its introduction in commit 78a33ab5 (v2.12). Noticed while debugging a separate failure reported by nbdkit while working out its initial implementation of BLOCK_STATUS, although it turns out that nbdkit also chose to send structured error replies for BLOCK_STATUS, so I had to manually provoke the situation by hacking qemu's server to send a simple error reply: | diff --git i/nbd/server.c w/nbd/server.c | index fd013a2817a..833288d7c45 100644 | 00--- i/nbd/server.c | +++ w/nbd/server.c | @@ -2269,6 +2269,8 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, | "discard failed", errp); | | case NBD_CMD_BLOCK_STATUS: | + return nbd_co_send_simple_reply(client, request->handle, ENOMEM, | + NULL, 0, errp); | if (!request->len) { | return nbd_send_generic_reply(client, request->handle, -EINVAL, | "need non-zero length", errp); | Signed-off-by: Eric Blake <eblake@redhat.com> Acked-by: Richard W.M. Jones <rjones@redhat.com> Message-Id: <20190325190104.30213-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-03-30nbd: Don't lose server's error to NBD_CMD_BLOCK_STATUSEric Blake
When the server replies with a (structured [*]) error to NBD_CMD_BLOCK_STATUS, without any extent information sent first, the client code was blindly throwing away the server's error code and instead telling the caller that EIO occurred. This has been broken since its introduction in 78a33ab5 (v2.12, where we should have called: error_setg(&local_err, "Server did not reply with any status extents"); nbd_iter_error(&iter, false, -EIO, &local_err); to declare the situation as a non-fatal error if no earlier error had already been flagged, rather than just blindly slamming iter.err and iter.ret), although it is more noticeable since commit 7f86068d, which actually tries hard to preserve the server's code thanks to a separate iter.request_ret. [*] The spec is clear that the server is also permitted to reply with a simple error, but that's a separate fix. I was able to provoke this scenario with a hack to the server, then seeing whether ENOMEM makes it back to the caller: | diff --git a/nbd/server.c b/nbd/server.c | index fd013a2817a..29c7995de02 100644 | --- a/nbd/server.c | +++ b/nbd/server.c | @@ -2269,6 +2269,8 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, | "discard failed", errp); | | case NBD_CMD_BLOCK_STATUS: | + return nbd_send_generic_reply(client, request->handle, -ENOMEM, | + "no status for you today", errp); | if (!request->len) { | return nbd_send_generic_reply(client, request->handle, -EINVAL, | "need non-zero length", errp); | -- Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190325190104.30213-2-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-03-30nbd: Tolerate some server non-compliance in NBD_CMD_BLOCK_STATUSEric Blake
The NBD spec states that NBD_CMD_FLAG_REQ_ONE (which we currently always use) should not reply with an extent larger than our request, and that the server's response should be exactly one extent. Right now, that means that if a server sends more than one extent, we treat the server as broken, fail the block status request, and disconnect, which prevents all further use of the block device. But while good software should be strict in what it sends, it should be tolerant in what it receives. While trying to implement NBD_CMD_BLOCK_STATUS in nbdkit, we temporarily had a non-compliant server sending too many extents in spite of REQ_ONE. Oddly enough, 'qemu-img convert' with qemu 3.1 failed with a somewhat useful message: qemu-img: Protocol error: invalid payload for NBD_REPLY_TYPE_BLOCK_STATUS which then disappeared with commit d8b4bad8, on the grounds that an error message flagged only at the time of coroutine teardown is pointless, and instead we should rely on the actual failed API to report an error - in other words, the 3.1 behavior was masking the fact that qemu-img was not reporting an error. That has since been fixed in the previous patch, where qemu-img convert now fails with: qemu-img: error while reading block status of sector 0: Invalid argument But even that is harsh. Since we already partially relaxed things in commit acfd8f7a to tolerate a server that exceeds the cap (although that change was made prior to the NBD spec actually putting a cap on the extent length during REQ_ONE - in fact, the NBD spec change was BECAUSE of the qemu behavior prior to that commit), it's not that much harder to argue that we should also tolerate a server that sends too many extents. But at the same time, it's nice to trace when we are being tolerant of server non-compliance, in order to help server writers fix their implementations to be more portable (if they refer to our traces, rather than just stderr). Reported-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190323212639.579-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-03-26file-posix: Support BDRV_REQ_NO_FALLBACK for zero writesKevin Wolf
We know that the kernel implements a slow fallback code path for BLKZEROOUT, so if BDRV_REQ_NO_FALLBACK is given, we shouldn't call it. The other operations we call in the context of .bdrv_co_pwrite_zeroes should usually be quick, so no modification should be needed for them. If we ever notice that there are additional problematic cases, we can still make these conditional as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Eric Blake <eblake@redhat.com>
2019-03-26block: Advertise BDRV_REQ_NO_FALLBACK in filter driversKevin Wolf
Filter drivers that support .bdrv_co_pwrite_zeroes can safely advertise BDRV_REQ_NO_FALLBACK because they just forward the request flags to their child node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Eric Blake <eblake@redhat.com>
2019-03-26block: Add BDRV_REQ_NO_FALLBACKKevin Wolf
For qemu-img convert, we want an operation that zeroes out the whole image if this can be done efficiently, but that returns an error otherwise so we don't write explicit zeroes and immediately overwrite them with the real data, potentially doubling the amount of data to be written. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Eric Blake <eblake@redhat.com>
2019-03-26block: Remove error messages in bdrv_make_zero()Kevin Wolf
There is only a single caller of bdrv_make_zero(), which is qemu-img convert. If the function fails, we just fall back to a different method of zeroing out blocks on the target image. There is no good reason to print error messages on stderr when the higher level operation will actually succeed. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Eric Blake <eblake@redhat.com>
2019-03-22trace-events: Delete unused trace pointsMarkus Armbruster
Tracked down with cleanup-trace-events.pl. Funnies requiring manual post-processing: * block.c and blockdev.c trace points are in block/trace-events. * hw/block/nvme.c uses the preprocessor to hide its trace point use from cleanup-trace-events.pl. * include/hw/xen/xen_common.h trace points are in hw/xen/trace-events. * net/colo-compare and net/filter-rewriter.c use pseudo trace points colo_compare_udp_miscompare and colo_filter_rewriter_debug to guard debug code. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-id: 20190314180929.27722-5-armbru@redhat.com Message-Id: <20190314180929.27722-5-armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-03-22trace-events: Shorten file names in commentsMarkus Armbruster
We spell out sub/dir/ in sub/dir/trace-events' comments pointing to source files. That's because when trace-events got split up, the comments were moved verbatim. Delete the sub/dir/ part from these comments. Gets rid of several misspellings. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190314180929.27722-3-armbru@redhat.com Message-Id: <20190314180929.27722-3-armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-03-19block: Make bdrv_{copy_on_read,crypto_luks,replication} staticAlberto Garcia
Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-19vmdk: Support version=3 in VMDK descriptor filesSam Eiderman
Commit 509d39aa22909c0ed1aabf896865f19c81fb38a1 added support for read only VMDKs of version 3. This commit fixes the probe function to correctly handle descriptors of version 3. This commit has two effects: 1. We no longer need to supply '-f vmdk' when pointing to descriptor files of version 3 in qemu/qemu-img command line arguments. 2. This fixes the scenario where a VMDK points to a parent version 3 descriptor file which is being probed as "raw" instead of "vmdk". Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Shmuel Eiderman <shmuel.eiderman@oracle.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-19qcow2: Fix data file error condition in qcow2_co_create()Kevin Wolf
We were trying to check whether bdrv_open_blockdev_ref() returned success, but accidentally checked the wrong variable. Spotted by Coverity (CID 1399703). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2019-03-19mirror: Confirm we're quiesced only if the job is paused or cancelledSergio Lopez
While child_job_drained_begin() calls to job_pause(), the job doesn't actually transition between states until it runs again and reaches a pause point. This means bdrv_drained_begin() may return with some jobs using the node still having 'busy == true'. As a consequence, block_job_detach_aio_context() may get into a deadlock, waiting for the job to be actually paused, while the coroutine servicing the job is yielding and doesn't get the opportunity to get scheduled again. This situation can be reproduced by issuing a 'block-commit' immediately followed by a 'device_del'. To ensure bdrv_drained_begin() only returns when the jobs have been paused, we change mirror_drained_poll() to only confirm it's quiesced when job->paused == true and there aren't any in-flight requests, except if we reached that point by a drained section initiated by the mirror/commit job itself. The other block jobs shouldn't need any changes, as the default drained_poll() behavior is to only confirm it's quiesced if the job is not busy or completed. Signed-off-by: Sergio Lopez <slp@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-14Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into ↵Peter Maydell
staging Pull request * Add 'drop-cache=on|off' option to file-posix.c. The default is on. Disabling the option fixes a QEMU 3.0.0 performance regression when live migrating on the same host with cache.direct=off. # gpg: Signature made Wed 13 Mar 2019 11:07:48 GMT # gpg: using RSA key 9CA4ABB381AB73C8 # gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full] # gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" [full] # Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8 * remotes/stefanha/tags/block-pull-request: file-posix: add drop-cache=on|off option Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-03-13Merge remote-tracking branch 'remotes/jnsnow/tags/bitmaps-pull-request' into ↵Peter Maydell
staging Pull request # gpg: Signature made Tue 12 Mar 2019 20:23:08 GMT # gpg: using RSA key F9B7ABDBBCACDF95BE76CBD07DEF8106AAFC390E # gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>" [full] # Primary key fingerprint: FAEB 9711 A12C F475 812F 18F2 88A9 064D 1835 61EB # Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76 CBD0 7DEF 8106 AAFC 390E * remotes/jnsnow/tags/bitmaps-pull-request: (22 commits) tests/qemu-iotests: add bitmap resize test 246 block/qcow2-bitmap: Allow resizes with persistent bitmaps block/qcow2-bitmap: Don't check size for IN_USE bitmap docs/interop/qcow2: Improve bitmap flag in_use specification bitmaps: Fix typo in function name block/dirty-bitmaps: implement inconsistent bit block/dirty-bitmaps: disallow busy bitmaps as merge source block/dirty-bitmaps: prohibit removing readonly bitmaps block/dirty-bitmaps: prohibit readonly bitmaps for backups block/dirty-bitmaps: add block_dirty_bitmap_check function block/dirty-bitmap: add inconsistent status block/dirty-bitmaps: add inconsistent bit iotests: add busy/recording bit test to 124 blockdev: remove unused paio parameter documentation block/dirty-bitmaps: move comment block block/dirty-bitmaps: unify qmp_locked and user_locked calls block/dirty-bitmap: explicitly lock bitmaps with successors nbd: change error checking order for bitmaps block/dirty-bitmap: change semantics of enabled predicate block/dirty-bitmap: remove set/reset assertions against enabled bit ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org> # Conflicts: # tests/qemu-iotests/group
2019-03-13file-posix: add drop-cache=on|off optionStefan Hajnoczi
Commit dd577a26ff03b6829721b1ffbbf9e7c411b72378 ("block/file-posix: implement bdrv_co_invalidate_cache() on Linux") introduced page cache invalidation so that cache.direct=off live migration is safe on Linux. The invalidation takes a significant amount of time when the file is large and present in the page cache. Normally this is not the case for cross-host live migration but it can happen when migrating between QEMU processes on the same host. On same-host migration we don't need to invalidate pages for correctness anyway, so an option to skip page cache invalidation is useful. I investigated optimizing invalidation and detecting same-host migration, but both are hard to achieve so a user-visible option will suffice. As a bonus this option means that the cache invalidation feature will now be detectable by libvirt via QMP schema introspection. Suggested-by: Neil Skrypuch <neil@tembosocial.com> Tested-by: Neil Skrypuch <neil@tembosocial.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190307164941.3322-1-stefanha@redhat.com Message-Id: <20190307164941.3322-1-stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-03-12block: Remove the AioContext parameter from bdrv_reopen_multiple()Alberto Garcia
This parameter has been unused since 1a63a907507fbbcfaee3f622907ec244b Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12block: Add a 'mutable_opts' field to BlockDriverAlberto Garcia
If we reopen a BlockDriverState and there is an option that is present in bs->options but missing from the new set of options then we have to return an error unless the driver is able to reset it to its default value. This patch adds a new 'mutable_opts' field to BlockDriver. This is a list of runtime options that can be modified during reopen. If an option in this list is unspecified on reopen then it must be reset (or return an error). Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12block: Add 'keep_old_opts' parameter to bdrv_reopen_queue()Alberto Garcia
The bdrv_reopen_queue() function is used to create a queue with the BDSs that are going to be reopened and their new options. Once the queue is ready bdrv_reopen_multiple() is called to perform the operation. The original options from each one of the BDSs are kept, with the new options passed to bdrv_reopen_queue() applied on top of them. For "x-blockdev-reopen" we want a function that behaves much like "blockdev-add". We want to ignore the previous set of options so that only the ones actually specified by the user are applied, with the rest having their default values. One of the things that we need is a way to tell bdrv_reopen_queue() whether we want to keep the old set of options or not, and that's what this patch does. All current callers are setting this new parameter to true and x-blockdev-reopen will set it to false. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>