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2019-02-25block/curl: Harmonize option defaultsMax Reitz
Both of the defaults we currently have in the curl driver are named based on a slightly different schema, let's unify that and call both CURL_BLOCK_OPT_${NAME}_DEFAULT. While at it, we can add a macro for the third option for which a default exists, namely "sslverify". Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-28-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block/nvme: Fix bdrv_refresh_filename()Max Reitz
Currently, nvme's bdrv_refresh_filename() is an exact copy of null's implementation. However, for null, "null-co://" and "null-aio://" are indeed valid filenames -- for nvme, they are not, as a device address is still required. The correct implementation should generate a filename of the form "nvme://[PCI address]/[namespace]" (as the comment above nvme_parse_filename() describes). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-27-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Do not copy exact_filename from format fileMax Reitz
If a format BDS's file BDS is in turn a format BDS, we cannot simply use the same filename, because when opening a BDS tree based on a filename alone, qemu will create only one format node on top of one protocol node (disregarding a potential backing file). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-26-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Purify .bdrv_refresh_filename()Max Reitz
Currently, BlockDriver.bdrv_refresh_filename() is supposed to both refresh the filename (BDS.exact_filename) and set BDS.full_open_options. Now that we have generic code in the central bdrv_refresh_filename() for creating BDS.full_open_options, we can drop the latter part from all BlockDriver.bdrv_refresh_filename() implementations. This also means that we can drop all of the existing default code for this from the global bdrv_refresh_filename() itself. Furthermore, we now have to call BlockDriver.bdrv_refresh_filename() after having set BDS.full_open_options, because the block driver's implementation should now be allowed to depend on BDS.full_open_options being set correctly. Finally, with this patch we can drop the @options parameter from BlockDriver.bdrv_refresh_filename(); also, add a comment on this function's purpose in block/block_int.h while touching its interface. This completely obsoletes blklogwrite's implementation of .bdrv_refresh_filename(). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190201192935.18394-25-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Generically refresh runtime optionsMax Reitz
Instead of having every block driver which implements bdrv_refresh_filename() copy all of the strong runtime options over to bs->full_open_options, implement this process generically in bdrv_refresh_filename(). This patch only adds this new generic implementation, it does not remove the old functionality. This is done in a follow-up patch. With this patch, some superfluous information (that should never have been there) may be removed from some JSON filenames, as can be seen in the change to iotests 110's and 228's reference outputs. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190201192935.18394-24-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Add BlockDriver.bdrv_gather_child_optionsMax Reitz
Some follow-up patches will rework the way bs->full_open_options is refreshed in bdrv_refresh_filename(). The new implementation will remove the need for the block drivers' bdrv_refresh_filename() implementations to set bs->full_open_options; instead, it will be generic and use static information from each block driver. However, by implementing bdrv_gather_child_options(), block drivers will still be able to override the way the full_open_options of their children are incorporated into their own. We need to implement this function for VMDK because we have to prevent the generic implementation from gathering the options of all children: It is not possible to specify options for the extents through the runtime options. For quorum, the child names that would be used by the generic implementation and the ones that we actually (currently) want to use differ. See quorum_gather_child_options() for more information. Note that both of these are cases which are not ideal: In case of VMDK it would probably be nice to be able to specify options for all extents. In case of quorum, the current runtime option structure is simply broken and needs to be fixed (but that is left for another patch). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-23-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Add strong_runtime_opts to BlockDriverMax Reitz
This new field can be set by block drivers to list the runtime options they accept that may influence the contents of the respective BDS. As of a follow-up patch, this list will be used by the common bdrv_refresh_filename() implementation to decide which options to put into BDS.full_open_options (and consequently whether a JSON filename has to be created), thus freeing the drivers of having to implement that logic themselves. Additionally, this patch adds the field to all of the block drivers that need it and sets it accordingly. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-22-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25iotests: Add quorum case to test 110Max Reitz
Test 110 tests relative backing filenames for complex BDS trees. Now that the originally supposedly failing test passes, let us add a new failing test: Quorum can never work automatically (without detecting whether all child nodes have the same base directory, but that would be rather inconsistent behavior). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-21-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Use bdrv_dirname() for relative filenamesMax Reitz
bdrv_get_full_backing_filename_from_filename() breaks down when it comes to JSON filenames. Using bdrv_dirname() as the basis is better because since we have BDS, we can descend through the BDS tree to the protocol layer, which gives us a greater probability of finding a non-JSON name; also, bdrv_dirname() is more correct as it allows block drivers to override the generation of that directory name in a protocol-specific way. We still need to keep bdrv_get_full_backing_filename_from_filename(), though, because it has valid callers which need it during image creation when no BDS is available yet. This makes a test case in qemu-iotest 110, which was supposed to fail, work. That is actually good, but we need to change the reference output (and the comment in 110) accordingly. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-20-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block/nfs: Implement bdrv_dirname()Max Reitz
While the basic idea is obvious and could be handled by the default bdrv_dirname() implementation, we cannot generate a directory name if the gid or uid are set, so we have to explicitly return NULL in those cases. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-19-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block/nbd: Make bdrv_dirname() return NULLMax Reitz
The generic bdrv_dirname() implementation would be able to generate some form of directory name for many NBD nodes, but it would be always wrong. Therefore, we have to explicitly make it an error (until NBD has some form of specification for export paths, if it ever will). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20190201192935.18394-18-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25quorum: Make bdrv_dirname() return NULLMax Reitz
While the common implementation for bdrv_dirname() should return NULL for quorum BDSs already (because they do not have a file node and their exact_filename field should be empty), there is no reason not to make that explicit. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-17-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25blkverify: Make bdrv_dirname() return NULLMax Reitz
blkverify's BDSs have a file BDS, but we do not want this to be preferred over the raw node. There is no way to decide between the two (and not really a reason to, either), so just return NULL in blkverify's implementation of bdrv_dirname(). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-16-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Add bdrv_dirname()Max Reitz
This function may be implemented by block drivers to derive a directory name from a BDS. Concatenating this g_free()-able string with a relative filename must result in a valid (not necessarily existing) filename, so this is a function that should generally be not implemented by format drivers, because this is protocol-specific. If a BDS's driver does not implement this function, bdrv_dirname() will fall through to the BDS's file if it exists. If it does not, the exact_filename field will be used to generate a directory name. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-15-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Fix bdrv_find_backing_image()Max Reitz
bdrv_find_backing_image() should use bdrv_get_full_backing_filename() or bdrv_make_absolute_filename() instead of trying to do what those functions do by itself. path_combine_deprecated() can now be dropped, so let's do that. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-14-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Add bdrv_make_absolute_filename()Max Reitz
This is a general function for making a filename that is relative to a certain BDS absolute. It calls bdrv_get_full_backing_filename_from_filename() for now, but that will be changed in a follow-up patch. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-13-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: bdrv_get_full_backing_filename's ret. val.Max Reitz
Make bdrv_get_full_backing_filename() return an allocated string instead of placing the result in a caller-provided buffer. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-12-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: bdrv_get_full_backing_filename_from_...'s ret. val.Max Reitz
Make bdrv_get_full_backing_filename_from_filename() return an allocated string instead of placing the result in a caller-provided buffer. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190201192935.18394-11-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Make path_combine() return the pathMax Reitz
Besides being safe for arbitrary path lengths, after some follow-up patches all callers will want a freshly allocated buffer anyway. In the meantime, path_combine_deprecated() is added which has the same interface as path_combine() had before this patch. All callers to that function will be converted in follow-up patches. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 20190201192935.18394-10-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25iotests: Add test for backing file overridesMax Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190201192935.18394-9-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25iotests.py: Add node_info()Max Reitz
This function queries a node; since we cannot do that right now, it executes query-named-block-nodes and returns the matching node's object. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20190201192935.18394-8-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25iotests.py: Add filter_imgfmt()Max Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190201192935.18394-7-mreitz@redhat.com Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Respect backing bs in bdrv_refresh_filenameMax Reitz
Basically, bdrv_refresh_filename() should respect all children of a BlockDriverState. However, generally those children are driver-specific, so this function cannot handle the general case. On the other hand, there are only few drivers which use other children than @file and @backing (that being vmdk, quorum, and blkverify). Most block drivers only use @file and/or @backing (if they use any children at all). Both can be implemented directly in bdrv_refresh_filename. The user overriding the file's filename is already handled, however, the user overriding the backing file is not. If this is done, opening the BDS with the plain filename of its file will not be correct, so we may not set bs->exact_filename in that case. iotest 051 contains test cases for overriding the backing file, and so its output changes with this patch applied. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-6-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Add BDS.auto_backing_fileMax Reitz
If the backing file is overridden, this most probably does change the guest-visible data of a BDS. Therefore, we will need to consider this in bdrv_refresh_filename(). To see whether it has been overridden, we might want to compare bs->backing_file and bs->backing->bs->filename. However, bs->backing_file is changed by bdrv_set_backing_hd() (which is just used to change the backing child at runtime, without modifying the image header), so bs->backing_file most of the time simply contains a copy of bs->backing->bs->filename anyway, so it is useless for such a comparison. This patch adds an auto_backing_file BDS field which contains the backing file path as indicated by the image header, which is not changed by bdrv_set_backing_hd(). Because of bdrv_refresh_filename() magic, however, a BDS's filename may differ from what has been specified during bdrv_open(). Then, the comparison between bs->auto_backing_file and bs->backing->bs->filename may fail even though bs->backing was opened from bs->auto_backing_file. To mitigate this, we can copy the real BDS's filename (after the whole bdrv_open() and bdrv_refresh_filename() process) into bs->auto_backing_file, if we know the former has been opened based on the latter. This is only possible if no options modifying the backing file's behavior have been specified, though. To simplify things, this patch only copies the filename from the backing file if no options have been specified for it at all. Furthermore, there are cases where an overlay is created by qemu which already contains a BDS's filename (e.g. in blockdev-snapshot-sync). We do not need to worry about updating the overlay's bs->auto_backing_file there, because we actually wrote a post-bdrv_refresh_filename() filename into the image header. So all in all, there will be false negatives where (as of a future patch) bdrv_refresh_filename() will assume that the backing file differs from what was specified in the image header, even though it really does not. However, these cases should be limited to where (1) the user actually did override something in the backing chain (e.g. by specifying options for the backing file), or (2) the user executed a QMP command to change some node's backing file (e.g. change-backing-file or block-commit with @backing-file given) where the given filename does not happen to coincide with qemu's idea of the backing BDS's filename. Then again, (1) really is limited to -drive. With -blockdev or blockdev-add, you have to adhere to the schema, so a user cannot give partial "unimportant" options (e.g. by just setting backing.node-name and leaving the rest to the image header). Therefore, trying to fix this would mean trying to fix something for -drive only. To improve on (2), we would need a full infrastructure to "canonicalize" an arbitrary filename (+ options), so it can be compared against another. That seems a bit over the top, considering that filenames nowadays are there mostly for the user's entertainment. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-5-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Skip implicit nodes for filename infoMax Reitz
bdrv_refresh_filename() should simply skip all implicit nodes. They are supposed to be invisible to the user, so they should not appear in filename information. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-4-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Use children list in bdrv_refresh_filenameMax Reitz
bdrv_refresh_filename() should invoke itself recursively on all children, not just on file. With that change, we can remove the manual invocations in blkverify, quorum, commit, mirror, and blklogwrites. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-3-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Use bdrv_refresh_filename() to pullMax Reitz
Before this patch, bdrv_refresh_filename() is used in a pushing manner: Whenever the BDS graph is modified, the parents of the modified edges are supposed to be updated (recursively upwards). However, that is nonviable, considering that we want child changes not to concern parents. Also, in the long run we want a pull model anyway: Here, we would have a bdrv_filename() function which returns a BDS's filename, freshly constructed. This patch is an intermediate step. It adds bdrv_refresh_filename() calls before every place a BDS.filename value is used. The only exceptions are protocol drivers that use their own filename, which clearly would not profit from refreshing that filename before. Also, bdrv_get_encrypted_filename() is removed along the way (as a user of BDS.filename), since it is completely unused. In turn, all of the calls to bdrv_refresh_filename() before this patch are removed, because we no longer have to call this function on graph changes. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190201192935.18394-2-mreitz@redhat.com Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block/nvme: Remove QEMU_PACKED from naturally aligned NVMeRegs structThomas Huth
The QEMU_PACKED is causing a compiler warning/error with GCC 9: CC block/nvme.o block/nvme.c: In function ‘nvme_create_queue_pair’: block/nvme.c:209:22: error: taking address of packed member of ‘struct <anonymous>’ may result in an unaligned pointer value [-Werror=address-of-packed-member] 209 | q->sq.doorbell = &s->regs->doorbells[idx * 2 * s->doorbell_scale]; All members of the struct are naturally aligned, so there should not be the need for QEMU_PACKED here, and the following QEMU_BUILD_BUG_ON also ensures that there is no padding. Thus simply remove the QEMU_PACKED here. Buglink: https://bugs.launchpad.net/qemu/+bug/1817525 Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25qcow2: Assert that L2 table offsets fit in the L1 tableAlberto Garcia
L1 table entries have a field to store the offset of an L2 table. The rest of the bits of the entry are currently reserved except from bit 63, which stores the COPIED flag. The offset is always taken from the entry using L1E_OFFSET_MASK to ensure that we only use the bits that belong to that field. While that mask is used every time we read from the L1 table, it is never used when we write to it. Due to the limits set elsewhere in the code QEMU can never produce L2 table offsets that don't fit in that field so any such offset when allocating an L2 table would indicate a bug in QEMU. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25tests: add test-bdrv-graph-modVladimir Sementsov-Ogievskiy
Add two tests of node graph modification. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25block: fix bdrv_check_perm for non-tree subgraphVladimir Sementsov-Ogievskiy
bdrv_check_perm in it's recursion checks each node in context of new permissions for one parent, because of nature of DFS. It works well, while children subgraph of top-most updated node is a tree, i.e. it doesn't have any kind of loops. But if we have a loop (not oriented, of course), i.e. we have two different ways from top-node to some child-node, then bdrv_check_perm will do wrong thing: top | \ | | v v A B | | v v node It will once check new permissions of node in context of new A permissions and old B permissions and once visa-versa. It's a wrong way and may lead to corruption of permission system. We may start with no-permissions and all-shared for both A->node and B->node relations and finish up with non shared write permission for both ways. The following commit will add a test, which shows this bug. To fix this situation, let's really set BdrvChild permissions during bdrv_check_perm procedure. And we are happy here, as check-perm is already written in transaction manner, so we just need to restore backed-up permissions in _abort. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25block: improve should_update_childVladimir Sementsov-Ogievskiy
As it already said in the comment, we don't want to create loops in parent->child relations. So, when we try to append @to to @c, we should check that @c is not in @to children subtree, and we should check it recursively, not only the first level. The patch provides BFS-based search, to check the relations. This is needed for further fleecing-hook filter usage: we need to append it to source, when the hook is already a parent of target, and source may be in a backing chain of target (fleecing-scheme). So, on appending, the hook should not became a child (direct or through children subtree) of the target. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25aio-posix: Assert that aio_poll() is always called in home threadKevin Wolf
aio_poll() has an existing assertion that the function is only called from the AioContext's home thread if blocking is allowed. This is not enough, some handlers make assumptions about the thread they run in. Extend the assertion to non-blocking calls, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25block: Use normal drain for bdrv_set_aio_context()Kevin Wolf
Now that bdrv_set_aio_context() works inside drained sections, it can also use the real drain function instead of open coding something similar. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25test-bdrv-drain: AioContext switch in drained sectionKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25block: Fix AioContext switch for drained nodeKevin Wolf
When a drained node changes its AioContext, we need to move its aio_disable_external() to the new context, too. Without this fix, drain_end will try to reenable the new context, which has never been disabled, so an assertion failure is triggered. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25block: Don't poll in bdrv_set_aio_context()Kevin Wolf
The explicit aio_poll() call in bdrv_set_aio_context() was added in commit c2b6428d388 as a workaround for bdrv_drain() failing to achieve to actually quiesce everything (specifically the NBD client code to switch AioContext). Now that the NBD client has been fixed to complete this operation during bdrv_drain(), we don't need the workaround any more. It was wrong anyway: aio_poll() must always be run in the home thread of the AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25nbd: Increase bs->in_flight during AioContext switchKevin Wolf
bdrv_drain() must not leave connection_co scheduled, so bs->in_flight needs to be increased while the coroutine is waiting to be scheduled in the new AioContext after nbd_client_attach_aio_context(). Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25nbd: Use low-level QIOChannel API in nbd_read_eof()Kevin Wolf
Instead of using the convenience wrapper qio_channel_read_all_eof(), use the lower level QIOChannel API. This means duplicating some code, but we'll need this because this coroutine yield is special: We want it to be interruptible so that nbd_client_attach_aio_context() can correctly reenter the coroutine. This moves the bdrv_dec/inc_in_flight() pair into nbd_read_eof(), so that connection_co will always sit in this exact qio_channel_yield() call when bdrv_drain() returns. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25nbd: Move nbd_read_eof() to nbd/client.cKevin Wolf
The only caller of nbd_read_eof() is nbd_receive_reply(), so it doesn't have to live in the header file, but can move next to its caller. Also add the missing coroutine_fn to the function and its caller. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25io: Remove redundant read/write_coroutine assignmentsKevin Wolf
qio_channel_yield() now updates ioc->read_write/coroutine and calls qio_channel_set_aio_fd_handlers(), so the code in the handlers has become redundant and can be removed. This does not make a difference in intermediate states because aio_co_wake() really enters the coroutine immediately here: These handlers are never run in coroutine context, and we're in the right AioContext because qio_channel_attach_aio_context() asserts that the handlers are inactive. To make these conditions more obvious, assert the right AioContext. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25io: Make qio_channel_yield() interruptibleKevin Wolf
Similar to how qemu_co_sleep_ns() allows preemption from an external coroutine entry, allow reentering qio_channel_yield() early. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25nbd: Restrict connection_co reentranceKevin Wolf
nbd_client_attach_aio_context() schedules connection_co in the new AioContext and this way reenters it in any arbitrary place that has yielded. We can restrict this a bit to the function call where the coroutine actually sits waiting when it's idle. This doesn't solve any bug yet, but it shows where in the code we need to support this random reentrance and where we don't have to care. Add FIXME comments for the existing bugs that the rest of this series will fix. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25virtio-blk: Increase in_flight for request restart BHKevin Wolf
virtio_blk_dma_restart_bh() submits new requests, so in order to make sure that these requests are not started inside a drained section of the attached BlockBackend, we need to make sure that draining the BlockBackend waits for the BH to be executed. This BH is still questionable because its scheduled in the main thread instead of the configured iothread. Leave a FIXME comment for this. But with this fix, enabling the data plane at least waits for these requests (in bdrv_set_aio_context()) instead of changing the AioContext under their feet and making them run in the wrong thread, causing crashes and failures (e.g. due to missing locking). Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25block-backend: Make blk_inc/dec_in_flight publicKevin Wolf
For some users of BlockBackends, just increasing the in_flight counter is easier than implementing separate handlers in BlockDevOps. Make the helper functions for this public. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25qemu-img: fix error reporting for -objectDaniel P. Berrangé
Error reporting for user_creatable_add_opts_foreach was changed so that it no longer called 'error_report_err' in: commit 7e1e0c11127bde81cff260fc6859690435c509d6 Author: Markus Armbruster <armbru@redhat.com> Date: Wed Oct 17 10:26:43 2018 +0200 qom: Clean up error reporting in user_creatable_add_opts_foreach() Some callers were updated to pass in "&error_fatal" but all the ones in qemu-img were left passing NULL. As a result all errors went to /dev/null instead of being reported to the user. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25commit: Replace commit_top_bs on failure after deleting the block jobAlberto Garcia
If there's an error in commit_start() then the block job must be deleted before replacing commit_top_bs, otherwise it will fail because of lack of permissions. This happens since the permission system was introduced in 8dfba2797761d8a43744e4e6571c8175e448a478. Fortunately this bug doesn't seem to be possible to reproduce at the moment without changing the code. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25block: don't set the same contextDenis Plotnikov
Adds a fast path on aio context setting preventing unnecessary context setting routine. Also, it prevents issues with cyclic walk of child bds-es appeared because of registering aio walking notifiers: Call stack: 0 __GI_raise 1 __GI_abort 2 __assert_fail_base 3 __GI___assert_fail 4 bdrv_detach_aio_context (bs=0x55f54d65c000) <<< 5 bdrv_detach_aio_context (bs=0x55f54fc8a800) 6 bdrv_set_aio_context (bs=0x55f54fc8a800, ...) 7 block_job_attached_aio_context 8 bdrv_attach_aio_context (bs=0x55f54d65c000, ...) <<< 9 bdrv_set_aio_context (bs=0x55f54d65c000) 10 blk_set_aio_context 11 virtio_blk_data_plane_stop 12 virtio_bus_stop_ioeventfd 13 virtio_vmstate_change 14 vm_state_notify (running=0, state=RUN_STATE_SHUTDOWN) 15 do_vm_stop (state=RUN_STATE_SHUTDOWN, send_stop=true) 16 vm_stop (state=RUN_STATE_SHUTDOWN) 17 main_loop_should_exit 18 main_loop 19 main This can happen because of "new" context attachment to VM disk bds. When attaching a new context the corresponding aio context handler is called for each of aio_notifiers registered on the VM disk bds context. Among those handlers, there is the block_job_attached_aio_context handler which sets a new aio context for the block job bds. When doing so, the old context is detached from all the block job bds children and one of them is the VM disk bds, serving as backing store for the blockjob bds, although the VM disk bds is actually the initializer of that process. Since the VM disk bds is protected with walking_aio_notifiers flag from double processing in recursive calls, the assert fires. Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25qcow2-snapshot: remove redundant find_snapshot_by_id_and_name callDaniel Henrique Barboza
In qcow2_snapshot_create there is the following code block: /* Generate an ID */ find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str)); /* Check that the ID is unique */ if (find_snapshot_by_id_and_name(bs, sn_info->id_str, NULL) >= 0) { return -EEXIST; } find_new_snapshot_id cycles through all snapshots, getting the id_str as an unsigned long int, calculating the max id_max value of all the existing id_strs and writing in the id_str pointer id_max + 1: for(i = 0; i < s->nb_snapshots; i++) { sn = s->snapshots + i; id = strtoul(sn->id_str, NULL, 10); if (id > id_max) id_max = id; } snprintf(id_str, id_str_size, "%lu", id_max + 1); Here, sn_info->id_str will have the unique value id_max + 1. Right after that, find_snapshot_by_id_and_name is called with id = sn_info->id_str and name = NULL. This will cause the function to execute the following: } else if (id) { for (i = 0; i < s->nb_snapshots; i++) { if (!strcmp(s->snapshots[i].id_str, id)) { return i; } } } In short, we're searching the existing snapshots to see if sn_info->id_str matches any existing id, right after we set in the previous line a sn_info->id_str value that is already unique. The first code block goes way back to commit 585f8587ad, a 2006 commit from Fabrice Bellard that simply says "new qcow2 disk image format". No more info is provided about this logic in any subsequent commits that moved this code block around. I can't say about the original design, but the current logic is redundant. bdrv_snapshot_create is called in aio_context lock, forbidding any concurrent call to accidentally create a new snapshot between the find_new_snapshot_id and find_snapshot_by_id_and_name calls. What we're ending up doing is to cycle through the snapshots two times for no viable reason. This patch eliminates the redundancy by removing the 'id is unique' check that calls find_snapshot_by_id_and_name. Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25block/snapshot: remove bdrv_snapshot_delete_by_id_or_nameDaniel Henrique Barboza
After the previous patch, the only instance of this function left is inside qemu-img.c. qemu-img is using it inside the 'img_snapshot' function to delete snapshots in the SNAPSHOT_DELETE case, based on a "snapshot_name" string that refers to the tag, not ID, of the QEMUSnapshotInfo struct. This can be verified by checking the SNAPSHOT_CREATE case that comes shortly before SNAPSHOT_DELETE. In that case, the same "snapshot_name" variable is being strcpy to the 'name' field of the QEMUSnapshotInfo struct sn: pstrcpy(sn.name, sizeof(sn.name), snapshot_name); Based on that, it is unlikely that "snapshot_name" might contain an "id" in SNAPSHOT_DELETE. This patch changes SNAPSHOT_DELETE to use snapshot_find() and snapshot_delete() instead of bdrv_snapshot_delete_by_id_or_name. After that, there is no instances left of bdrv_snapshot_delete_by_id_or_name in the code, so it is safe to remove it entirely. Suggested-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>