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2020-03-26block: trickle down the fallback image creation function use to the block ↵Maxim Levitsky
drivers Instead of checking the .bdrv_co_create_opts to see if we need the fallback, just implement the .bdrv_co_create_opts in the drivers that need it. This way we don't break various places that need to know if the underlying protocol/format really supports image creation, and this way we still allow some drivers to not support image creation. Fixes: fd17146cd93d1704cd96d7c2757b325fc7aac6fd Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1816007 Note that technically this driver reverts the image creation fallback for the vxhs driver since I don't have a means to test it, and IMHO it is better to leave it not supported as it was prior to generic image creation patches. Also drop iscsi_create_opts which was left accidentally. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200326011218.29230-3-mlevitsk@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> [mreitz: Fixed alignment, and moved bdrv_co_create_opts_simple() and bdrv_create_opts_simple from block.h into block_int.h] Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26block: pass BlockDriver reference to the .bdrv_co_createMaxim Levitsky
This will allow the reuse of a single generic .bdrv_co_create implementation for several drivers. No functional changes. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-11block: introducing 'bdrv_co_delete_file' interfaceDaniel Henrique Barboza
Adding to Block Drivers the capability of being able to clean up its created files can be useful in certain situations. For the LUKS driver, for instance, a failure in one of its authentication steps can leave files in the host that weren't there before. This patch adds the 'bdrv_co_delete_file' interface to block drivers and add it to the 'file' driver in file-posix.c. The implementation is given by 'raw_co_delete_file'. Suggested-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Message-Id: <20200130213907.2830642-2-danielhb413@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-11block: Make bdrv_get_cumulative_perm() publicKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200310113831.27293-2-kwolf@redhat.com> Reviewed-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-09monitor/hmp: Move hmp_drive_add_node to block-hmp-cmds.cMaxim Levitsky
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20200308092440.23564-12-mlevitsk@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-03-06block: Introduce 'bdrv_reopen_commit_post' stepPeter Krempa
Add another step in the reopen process where driver can execute code after permission changes are comitted. Signed-off-by: Peter Krempa <pkrempa@redhat.com> Message-Id: <adc02cf591c3cb34e98e33518eb1c540a0f27db1.1582893284.git.pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-18block: Remove bdrv_recurse_is_first_non_filter()Max Reitz
It no longer has any users. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200218103454.296704-11-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-18block: Add bdrv_recurse_can_replace()Max Reitz
After a couple of follow-up patches, this function will replace bdrv_recurse_is_first_non_filter() in check_to_replace_node(). bdrv_recurse_is_first_non_filter() is both not sufficiently specific for check_to_replace_node() (it allows cases that should not be allowed, like replacing child nodes of quorum with dissenting data that have more parents than just quorum), and it is too restrictive (it is perfectly fine to replace filters). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200218103454.296704-7-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-30block/io: wait for serialising requests when a request becomes serialisingPaolo Bonzini
Marking without waiting would not result in actual serialising behavior. Thus, make a call bdrv_mark_request_serialising sufficient for serialisation to happen. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1578495356-46219-3-git-send-email-pbonzini@redhat.com Message-Id: <1578495356-46219-3-git-send-email-pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@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>
2019-10-28block: 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>
2019-10-17qcow2-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: proper locking on bitmap add/remove pathsVladimir Sementsov-Ogievskiy
qmp_block_dirty_bitmap_add and do_block_dirty_bitmap_remove do acquire aio context since 0a6c86d024c52b. But this is not enough: we also must lock qcow2 mutex when access in-image metadata. Especially it concerns freeing qcow2 clusters. To achieve this, move qcow2_can_store_new_dirty_bitmap and qcow2_remove_persistent_dirty_bitmap to coroutine context. Since we work in coroutines in correct aio context, we don't need context acquiring in blockdev.c anymore, drop it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190920082543.23444-4-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/dirty-bitmap: return int from bdrv_remove_persistent_dirty_bitmapVladimir Sementsov-Ogievskiy
It's more comfortable to not deal with local_err. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190920082543.23444-3-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-10block/backup: use backup-top instead of write notifiersVladimir Sementsov-Ogievskiy
Drop write notifiers and use filter node instead. = Changes = 1. Add filter-node-name argument for backup qmp api. We have to do it in this commit, as 257 needs to be fixed. 2. There are no more write notifiers here, so is_write_notifier parameter is dropped from block-copy paths. 3. To sync with in-flight requests at job finish we now have drained removing of the filter, we don't need rw-lock. 4. Block-copy is now using BdrvChildren instead of BlockBackends 5. As backup-top owns these children, we also move block-copy state into backup-top's ownership. = Iotest changes = 56: op-blocker doesn't shoot now, as we set it on source, but then check on filter, when trying to start second backup. To keep the test we instead can catch another collision: both jobs will get 'drive0' job-id, as job-id parameter is unspecified. To prevent interleaving with file-posix locks (as they are dependent on config) let's use another target for second backup. Also, it's obvious now that we'd like to drop this op-blocker at all and add a test-case for two backups from one node (to different destinations) actually works. But not in these series. 141: Output changed: prepatch, "Node is in use" comes from bdrv_has_blk check inside qmp_blockdev_del. But we've dropped block-copy blk objects, so no more blk objects on source bs (job blk is on backup-top filter bs). New message is from op-blocker, which is the next check in qmp_blockdev_add. 257: The test wants to emulate guest write during backup. They should go to filter node, not to original source node, of course. Therefore we need to specify filter node name and use it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20191001131409.14202-6-vsementsov@virtuozzo.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-10qapi: query-blockstat: add driver specific file-posix statsAnton Nefedov
A block driver can provide a callback to report driver-specific statistics. file-posix driver now reports discard statistics Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Markus Armbruster <armbru@redhat.com> Message-id: 20190923121737.83281-10-anton.nefedov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-27block/io: introduce bdrv_co_p{read, write}v_partVladimir Sementsov-Ogievskiy
Introduce extended variants of bdrv_co_preadv and bdrv_co_pwritev with qiov_offset parameter. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-10-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-10-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-27block: define .*_part io handlers in BlockDriverVladimir Sementsov-Ogievskiy
Add handlers supporting qiov_offset parameter: bdrv_co_preadv_part bdrv_co_pwritev_part bdrv_co_pwritev_compressed_part This is used to reduce need of defining local_qiovs and hd_qiovs in all corners of block layer code. The following patches will increase usage of this new API part by part. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-5-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-5-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-19block: Add bdrv_has_zero_init_truncate()Max Reitz
No .bdrv_has_zero_init() implementation returns 1 if growing the file would add non-zero areas (at least with PREALLOC_MODE_OFF), so using it in lieu of this new function was always safe. But on the other hand, it is possible that growing an image that is not zero-initialized would still add a zero-initialized area, like when using nonpreallocating truncation on a preallocated image. For callers that care only about truncation, not about creation with potential preallocation, this new function is useful. Alternatively, we could have added a PreallocMode parameter to bdrv_has_zero_init(). But the only user would have been qemu-img convert, which does not have a plain PreallocMode value right now -- it would have to parse the creation option to obtain it. Therefore, the simpler solution is to let bdrv_has_zero_init() inquire the preallocation status and add the new bdrv_has_zero_init_truncate() that presupposes PREALLOC_MODE_OFF. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190724171239.8764-4-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19mirror: Fix bdrv_has_zero_init() useMax Reitz
bdrv_has_zero_init() only has meaning for newly created images or image areas. If the mirror job itself did not create the image, it cannot rely on bdrv_has_zero_init()'s result to carry any meaning. This is the case for drive-mirror with mode=existing and always for blockdev-mirror. Note that we only have to zero-initialize the target with sync=full, because other modes actually do not promise that the target will contain the same data as the source after the job -- sync=top only promises to copy anything allocated in the top layer, and sync=none will only copy new I/O. (Which is how mirror has always handled it.) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190724171239.8764-3-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-16block/dirty-bitmap: add bdrv_dirty_bitmap_merge_internalJohn Snow
I'm surprised it didn't come up sooner, but sometimes we have a +busy bitmap as a source. This is dangerous from the QMP API, but if we are the owner that marked the bitmap busy, it's safe to merge it using it as a read only source. It is not safe in the general case to allow users to read from in-use bitmaps, so create an internal variant that foregoes the safety checking. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20190709232550.10724-10-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16block/backup: Add mirror sync mode 'bitmap'John Snow
We don't need or want a new sync mode for simple differences in semantics. Create a new mode simply named "BITMAP" that is designed to make use of the new Bitmap Sync Mode field. Because the only bitmap sync mode is 'on-success', this adds no new functionality to the backup job (yet). The old incremental backup mode is maintained as a syntactic sugar for sync=bitmap, mode=on-success. Add all of the plumbing necessary to support this new instruction. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20190709232550.10724-6-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16Include qemu/main-loop.h lessMarkus Armbruster
In my "build everything" tree, changing qemu/main-loop.h triggers a recompile of some 5600 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). It includes block/aio.h, which in turn includes qemu/event_notifier.h, qemu/notify.h, qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h, qemu/thread.h, qemu/timer.h, and a few more. Include qemu/main-loop.h only where it's needed. Touching it now recompiles only some 1700 objects. For block/aio.h and qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the others, they shrink only slightly. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190812052359.30071-21-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-07-19block: Do not poll in bdrv_do_drained_end()Max Reitz
We should never poll anywhere in bdrv_do_drained_end() (including its recursive callees like bdrv_drain_invoke()), because it does not cope well with graph changes. In fact, it has been written based on the postulation that no graph changes will happen in it. Instead, the callers that want to poll must poll, i.e. all currently globally available wrappers: bdrv_drained_end(), bdrv_subtree_drained_end(), bdrv_unapply_subtree_drain(), and bdrv_drain_all_end(). Graph changes there do not matter. They can poll simply by passing a pointer to a drained_end_counter and wait until it reaches 0. This patch also adds a non-polling global wrapper for bdrv_do_drained_end() that takes a drained_end_counter pointer. We need such a variant because now no function called anywhere from bdrv_do_drained_end() must poll. This includes BdrvChildRole.drained_end(), which already must not poll according to its interface documentation, but bdrv_child_cb_drained_end() just violates that by invoking bdrv_drained_end() (which does poll). Therefore, BdrvChildRole.drained_end() must take a *drained_end_counter parameter, which bdrv_child_cb_drained_end() can pass on to the new bdrv_drained_end_no_poll() function. Note that we now have a pattern of all drained_end-related functions either polling or receiving a *drained_end_counter to let the caller poll based on that. A problem with a single poll loop is that when the drained section in bdrv_set_aio_context_ignore() ends, some nodes in the subgraph may be in the old contexts, while others are in the new context already. To let the collective poll in bdrv_drained_end() work correctly, we must not hold a lock to the old context, so that the old context can make progress in case it is different from the current context. (In the process, remove the comment saying that the current context is always the old context, because it is wrong.) In all other places, all nodes in a subtree must be in the same context, so we can just poll that. The exception of course is bdrv_drain_all_end(), but that always runs in the main context, so we can just poll NULL (like bdrv_drain_all_begin() does). Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19block: Introduce BdrvChild.parent_quiesce_counterMax Reitz
Commit 5cb2737e925042e6c7cd3fb0b01313950b03cddf laid out why bdrv_do_drained_end() must decrement the quiesce_counter after bdrv_drain_invoke(). It did not give a very good reason why it has to happen after bdrv_parent_drained_end(), instead only claiming symmetry to bdrv_do_drained_begin(). It turns out that delaying it for so long is wrong. Situation: We have an active commit job (i.e. a mirror job) from top to base for the following graph: filter | [file] | v top --[backing]--> base Now the VM is closed, which results in the job being cancelled and a bdrv_drain_all() happening pretty much simultaneously. Beginning the drain means the job is paused once whenever one of its nodes is quiesced. This is reversed when the drain ends. With how the code currently is, after base's drain ends (which means that it will have unpaused the job once), its quiesce_counter remains at 1 while it goes to undrain its parents (bdrv_parent_drained_end()). For some reason or another, undraining filter causes the job to be kicked and enter mirror_exit_common(), where it proceeds to invoke block_job_remove_all_bdrv(). Now base will be detached from the job. Because its quiesce_counter is still 1, it will unpause the job once more. So in total, undraining base will unpause the job twice. Eventually, this will lead to the job's pause_count going negative -- well, it would, were there not an assertion against this, which crashes qemu. The general problem is that if in bdrv_parent_drained_end() we undrain parent A, and then undrain parent B, which then leads to A detaching the child, bdrv_replace_child_noperm() will undrain A as if we had not done so yet; that is, one time too many. It follows that we cannot decrement the quiesce_counter after invoking bdrv_parent_drained_end(). Unfortunately, decrementing it before bdrv_parent_drained_end() would be wrong, too. Imagine the above situation in reverse: Undraining A leads to B detaching the child. If we had already decremented the quiesce_counter by that point, bdrv_replace_child_noperm() would undrain B one time too little; because it expects bdrv_parent_drained_end() to issue this undrain. But bdrv_parent_drained_end() won't do that, because B is no longer a parent. Therefore, we have to do something else. This patch opts for introducing a second quiesce_counter that counts how many times a child's parent has been quiesced (though c->role->drained_*). With that, bdrv_replace_child_noperm() just has to undrain the parent exactly that many times when removing a child, and it will always be right. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-15block: Add BDS.never_freezeMax Reitz
The commit and the mirror block job must be able to drop their filter node at any point. However, this will not be possible if any of the BdrvChild links to them is frozen. Therefore, we need to prevent them from ever becoming frozen. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190703172813.6868-2-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-06-18block: Add bdrv_child_refresh_perms()Max Reitz
If a block node uses bdrv_child_try_set_perm() to change the permission it takes on its child, the result may be very short-lived. If anything makes the block layer recalculate the permissions internally, it will invoke the node driver's .bdrv_child_perm() implementation. The permission/shared permissions masks that returns will then override the values previously passed to bdrv_child_try_set_perm(). If drivers want a child edge to have specific values for the permissions/shared permissions mask, it must return them in .bdrv_child_perm(). Consequentially, there is no need for them to pass the same values to bdrv_child_try_set_perm() then: It is better to have a function that invokes .bdrv_child_perm() and calls bdrv_child_try_set_perm() with the result. This patch adds such a function under the name of bdrv_child_refresh_perms(). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18block: drop bs->jobVladimir Sementsov-Ogievskiy
Drop remaining users of bs->job: 1. assertions actually duplicated by assert(!bs->refcnt) 2. trace-point seems not enough reason to change stream_start to return BlockJob pointer 3. Restricting creation of two jobs based on same bs is bad idea, as 3.1 Some jobs creates filters to be their main node, so, this check don't actually prevent creating second job on same real node (which will create another filter node) (but I hope it is restricted by other mechanisms) 3.2 Even without bs->job we have two systems of permissions: op-blockers and BLK_PERM 3.3 We may want to run several jobs on one node one day And finally, drop bs->job pointer itself. Hurrah! Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18block/replication: drop usage of bs->jobVladimir Sementsov-Ogievskiy
We are going to remove bs->job pointer. Drop it's usage in replication code. Additionally we have to return job pointer from some mirror APIs. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04block: Adjust AioContexts when attaching nodesKevin Wolf
So far, we only made sure that updating the AioContext of a node affected the whole subtree. However, if a node is newly attached to a new parent, we also need to make sure that both the subtree of the node and the parent are in the same AioContext. This tries to move the new child node to the parent AioContext and returns an error if this isn't possible. BlockBackends now actually apply their AioContext to their root node. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-20block: Propagate AioContext change to parentsKevin Wolf
All block nodes and users in any connected component of the block graph must be in the same AioContext, so changing the AioContext of one node must not only change all of its children, but all of its parents (and in turn their children etc.) as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-20block: Make bdrv_attach/detach_aio_context() staticKevin Wolf
Since commit b97511c7bc8, there is no reason for block drivers any more to call these functions (see the function comment in block_int.h). They are now just internal helper functions for bdrv_set_aio_context() and can be made static. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-20block: Add bdrv_try_set_aio_context()Kevin Wolf
Eventually, we want to make sure that all parents and all children of a node are in the same AioContext as the node itself. This means that changing the AioContext may fail because one of the other involved parties (e.g. a guest device that was configured with an iothread) cannot allow switching to a different AioContext. Introduce a set of functions that allow to first check whether all involved nodes can switch to a new context and only then do the actual switch. The check recursively covers children and parents. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30block: introduce byte-based io helpersVladimir 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>
2019-03-12block: 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: Allow freezing BdrvChild linksAlberto Garcia
Our permission system is useful to define what operations are allowed on a certain block node and includes things like BLK_PERM_WRITE or BLK_PERM_RESIZE among others. One of the permissions is BLK_PERM_GRAPH_MOD which allows "changing the node that this BdrvChild points to". The exact meaning of this has never been very clear, but it can be understood as "change any of the links connected to the node". This can be used to prevent changing a backing link, but it's too coarse. This patch adds a new 'frozen' attribute to BdrvChild, which forbids detaching the link from the node it points to, and new API to freeze and unfreeze a backing chain. After this change a few functions can fail, so they need additional checks. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08qcow2: Implement data-file-raw create optionKevin Wolf
Provide an option to force QEMU to always keep the external data file consistent as a standalone read-only raw image. At the moment, this means making sure that write_zeroes requests are forwarded to the data file instead of just updating the metadata, and checking that no backing file is used. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08qcow2: Creating images with external data fileKevin Wolf
This adds a .bdrv_create option to use an external data file. Signed-off-by: Kevin Wolf <kwolf@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: 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>
2019-02-25block: 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: 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: 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>
2019-02-11bdrv_query_image_info Error parameter addedAndrey Shinkevich
Inform a user in case qcow2_get_specific_info fails to obtain QCOW2 image specific information. This patch is preliminary to the one "qcow2: Add list of bitmaps to ImageInfoSpecificQCow2". Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <1549638368-530182-2-git-send-email-andrey.shinkevich@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2018-10-29dirty-bitmap: rename bdrv_undo_clear_dirty_bitmapVladimir Sementsov-Ogievskiy
Use more generic names to reuse the function for bitmap merge in the following commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com>
2018-09-25block: Use a single global AioWaitKevin Wolf
When draining a block node, we recurse to its parent and for subtree drains also to its children. A single AIO_WAIT_WHILE() is then used to wait for bdrv_drain_poll() to become true, which depends on all of the nodes we recursed to. However, if the respective child or parent becomes quiescent and calls bdrv_wakeup(), only the AioWait of the child/parent is checked, while AIO_WAIT_WHILE() depends on the AioWait of the original node. Fix this by using a single AioWait for all callers of AIO_WAIT_WHILE(). This may mean that the draining thread gets a few more unnecessary wakeups because an unrelated operation got completed, but we already wake it up when something _could_ have changed rather than only if it has certainly changed. Apart from that, drain is a slow path anyway. In theory it would be possible to use wakeups more selectively and still correctly, but the gains are likely not worth the additional complexity. In fact, this patch is a nice simplification for some places in the code. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-09-25block/stream: add block job creation flagsJohn Snow
Add support for taking and passing forward job creation flags. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20180906130225.5118-4-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-09-25block/mirror: add block job creation flagsJohn Snow
Add support for taking and passing forward job creation flags. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20180906130225.5118-3-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>