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2020-05-28block/dirty-bitmap: add bdrv_has_named_bitmaps helperVladimir Sementsov-Ogievskiy1-0/+13
To be used for bitmap migration in further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200521220648.3255-3-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2020-05-19block: Make it easier to learn which BDS support bitmapsEric Blake1-0/+9
Upcoming patches will enhance bitmap support in qemu-img, but in doing so, it turns out to be nice to suppress output when persistent bitmaps make no sense (such as on a qcow2 v2 image). Add a hook to make this easier to query. This patch adds a new callback .bdrv_supports_persistent_dirty_bitmap, rather than trying to shoehorn the answer in via existing callbacks. In particular, while it might have been possible to overload .bdrv_co_can_store_new_dirty_bitmap to special-case a NULL input to answer whether any persistent bitmaps are supported, that is at odds with whether a particular bitmap can be stored (for example, even on an image that supports persistent bitmaps but has currently filled up the maximum number of bitmaps, attempts to store another one should fail); and the new functionality doesn't require coroutine safety. Similarly, we could have added one more piece of information to .bdrv_get_info, but then again, most callers to that function tend to already discard extraneous information, and making it a catch-all rather than a series of dedicated scalar queries hasn't really simplified life. In the future, when we improve the ability to look up bitmaps through a filter, we will probably also want to teach the block layer to automatically let filters pass this request on through. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513011648.166876-4-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-03-18block/dirty-bitmap: improve _next_dirty_area APIVladimir Sementsov-Ogievskiy1-2/+4
Firstly, _next_dirty_area is for scenarios when we may contiguously search for next dirty area inside some limited region, so it is more comfortable to specify "end" which should not be recalculated on each iteration. Secondly, let's add a possibility to limit resulting area size, not limiting searching area. This will be used in NBD code in further commit. (Note that now bdrv_dirty_bitmap_next_dirty_area is unused) Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-8-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2020-03-18block/dirty-bitmap: add _next_dirty APIVladimir Sementsov-Ogievskiy1-0/+6
We have bdrv_dirty_bitmap_next_zero, let's add corresponding bdrv_dirty_bitmap_next_dirty, which is more comfortable to use than bitmap iterators in some cases. For test modify test_hbitmap_next_zero_check_range to check both next_zero and next_dirty and add some new checks. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-7-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2020-03-18block/dirty-bitmap: switch _next_dirty_area and _next_zero to int64_tVladimir Sementsov-Ogievskiy1-3/+3
We are going to introduce bdrv_dirty_bitmap_next_dirty so that same variable may be used to store its return value and to be its parameter, so it would int64_t. Similarly, we are going to refactor hbitmap_next_dirty_area to use hbitmap_next_dirty together with hbitmap_next_zero, therefore we want hbitmap_next_zero parameter type to be int64_t too. So, for convenience update all parameters of *_next_zero and *_next_dirty_area to be int64_t. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-6-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-11-18bitmap: Enforce maximum bitmap name lengthEric Blake1-3/+9
We document that for qcow2 persistent bitmaps, the name cannot exceed 1023 bytes. It is inconsistent if transient bitmaps do not have to abide by the same limit, and it is unlikely that any existing client even cares about using bitmap names this long. It's time to codify that ALL bitmaps managed by qemu (whether persistent in qcow2 or not) have a documented maximum length. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20191114024635.11363-3-eblake@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-10-17block/qcow2-bitmap: get rid of bdrv_has_changed_persistent_bitmapsVladimir Sementsov-Ogievskiy1-12/+0
Firstly, no reason to optimize failure path. Then, function name is ambiguous: it checks for readonly and similar things, but someone may think that it will ignore normal bitmaps which was just unchanged, and this is in bad relation with the fact that we should drop IN_USE flag for unchanged bitmaps in the image. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190927122355.7344-5-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/dirty-bitmap: refactor bdrv_dirty_bitmap_nextVladimir Sementsov-Ogievskiy1-4/+7
bdrv_dirty_bitmap_next is always used in same pattern. So, split it into _next and _first, instead of combining two functions into one and add FOR_EACH_DIRTY_BITMAP macro. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190916141911.5255-5-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/dirty-bitmap: drop BdrvDirtyBitmap.mutexVladimir Sementsov-Ogievskiy1-43/+41
mutex field is just a pointer to bs->dirty_bitmap_mutex, so no needs to store it in BdrvDirtyBitmap when we have bs pointer in it (since previous patch). Drop mutex field. Constantly use bdrv_dirty_bitmaps_lock/unlock in block/dirty-bitmap.c to make it more obvious that it's not per-bitmap lock. Still, for simplicity, leave bdrv_dirty_bitmap_lock/unlock functions as an external API. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190916141911.5255-4-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/dirty-bitmap: add bs linkVladimir Sementsov-Ogievskiy1-12/+12
Add bs field to BdrvDirtyBitmap structure. Drop BlockDriverState parameter from bitmap APIs where possible. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190916141911.5255-3-vsementsov@virtuozzo.com [Rebased on top of block-copy. --js] Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/dirty-bitmap: drop metaVladimir Sementsov-Ogievskiy1-46/+0
Drop meta bitmaps, as they are unused. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190916141911.5255-2-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/qcow2: proper locking on bitmap add/remove pathsVladimir Sementsov-Ogievskiy1-8/+94
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-Ogievskiy1-4/+5
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>
2019-10-17block: move bdrv_can_store_new_dirty_bitmap to block/dirty-bitmap.cVladimir Sementsov-Ogievskiy1-0/+22
block/dirty-bitmap.c seems to be more appropriate for it and bdrv_remove_persistent_dirty_bitmap already in it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190920082543.23444-2-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16qapi: implement block-dirty-bitmap-remove transaction actionJohn Snow1-8/+7
It is used to do transactional movement of the bitmap (which is possible in conjunction with merge command). Transactional bitmap movement is needed in scenarios with external snapshot, when we don't want to leave copy of the bitmap in the base image. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20190708220502.12977-3-jsnow@redhat.com [Edited "since" version to 4.2 --js] Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16block/dirty-bitmap: add bdrv_dirty_bitmap_getJohn Snow1-7/+12
Add a public interface for get. While we're at it, rename "bdrv_get_dirty_bitmap_locked" to "bdrv_dirty_bitmap_get_locked". (There are more functions to rename to the bdrv_dirty_bitmap_VERB form, but they will wait until the conclusion of this series.) Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20190709232550.10724-11-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16block/dirty-bitmap: add bdrv_dirty_bitmap_merge_internalJohn Snow1-5/+49
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>
2019-06-12Include qemu-common.h exactly where neededMarkus Armbruster1-1/+0
No header includes qemu-common.h after this commit, as prescribed by qemu-common.h's file comment. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190523143508.25387-5-armbru@redhat.com> [Rebased with conflicts resolved automatically, except for include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and net/tap-bsd.c fixed up]
2019-05-28qapi: support external bitmaps in block-dirty-bitmap-mergeVladimir Sementsov-Ogievskiy1-3/+6
Add new optional parameter making possible to merge bitmaps from different nodes. It is needed to maintain external snapshots during incremental backup chain history. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190517152111.206494-2-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12bitmaps: Fix typo in function nameEric Blake1-2/+2
Commit a88b179f introduced the ability to set and query bitmap persistence, but with an atypical spelling. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 20190308205845.25734-1-eblake@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmaps: disallow busy bitmaps as merge sourceJohn Snow1-0/+3
We didn't do any state checking on source bitmaps at all, so this adds inconsistent and busy checks. readonly is allowed, so you can still copy a readonly bitmap to a new destination to use it for operations like drive-backup. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190301191545.8728-7-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmaps: add block_dirty_bitmap_check functionJohn Snow1-12/+30
Instead of checking against busy, inconsistent, or read only directly, use a check function with permissions bits that let us streamline the checks without reproducing them in many places. Included in this patch are permissions changes that simply add the inconsistent check to existing permissions call spots, without addressing existing bugs. In general, this means that busy+readonly checks become BDRV_BITMAP_DEFAULT, which checks against all three conditions. busy-only checks become BDRV_BITMAP_ALLOW_RO. Notably, remove allows inconsistent bitmaps, so it doesn't follow the pattern. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190301191545.8728-4-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmap: add inconsistent statusJohn Snow1-1/+6
Even though the status field is deprecated, we still have to support it for a few more releases. Since this is a very new kind of bitmap state, it makes sense for it to have its own status field. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190301191545.8728-3-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmaps: add inconsistent bitJohn Snow1-0/+20
Add an inconsistent bit to dirty-bitmaps that allows us to report a bitmap as persistent but potentially inconsistent, i.e. if we find bitmaps on a qcow2 that have been marked as "in use". Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190301191545.8728-2-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmaps: move comment blockJohn Snow1-17/+19
Simply move the big status enum comment block to above the status function, and document it as being deprecated. The whole confusing block can get deleted in three releases time. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190223000614.13894-9-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmaps: unify qmp_locked and user_locked callsJohn Snow1-24/+19
These mean the same thing now. Unify them and rename the merged call bdrv_dirty_bitmap_busy to indicate semantically what we are describing, as well as help disambiguate from the various _locked and _unlocked versions of bitmap helpers that refer to mutex locks. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190223000614.13894-8-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmap: explicitly lock bitmaps with successorsJohn Snow1-5/+6
Instead of implying a user_locked/busy status, make it explicit. Now, bitmaps in use by migration, NBD or backup operations are all treated the same way with the same code paths. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190223000614.13894-7-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmap: change semantics of enabled predicateJohn Snow1-2/+7
Currently, the enabled predicate means something like: "the QAPI status of the bitmap is ACTIVE." After this patch, it should mean exclusively: "This bitmap is recording guest writes, and is allowed to do so." In many places, this is how this predicate was already used. Internal usages of the bitmap QPI can call user_locked to find out if the bitmap is in use by an operation. To accommodate this, modify the create_successor routine to now explicitly disable the parent bitmap at creation time. Justifications: 1. bdrv_dirty_bitmap_status suffers no change from the lack of 1:1 parity with the new predicates because of the order in which the predicates are checked. This is now only for compatibility. 2. bdrv_set_dirty() is unchanged: pre-patch, it was skipping bitmaps that were disabled or had a successor, while post-patch it is only skipping bitmaps that are disabled. To accommodate this, create_successor now ensures that any bitmap with a successor is explicitly disabled. 3. qcow2_store_persistent_dirty_bitmaps: No functional change. This function cares only about the literal enabled bit, and makes no effort to check if the bitmap is in-use or not. After this patch there are still no ways to produce an enabled bitmap with a successor. 4. block_dirty_bitmap_enable_prepare block_dirty_bitmap_disable_prepare init_dirty_bitmap_migration nbd_export_new These functions care about the literal enabled bit, and already check user_locked separately. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190223000614.13894-5-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmap: remove set/reset assertions against enabled bitJohn Snow1-2/+0
bdrv_set_dirty_bitmap and bdrv_reset_dirty_bitmap are only used as an internal API by the mirror and migration areas of our code. These calls modify the bitmap, but do so at the behest of QEMU and not the guest. Presently, these bitmaps are always "enabled" anyway, but there's no reason they have to be. Modify these internal APIs to drop this assertion. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190223000614.13894-4-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmaps: rename frozen predicate helperJohn Snow1-14/+18
"Frozen" was a good description a long time ago, but it isn't adequate now. Rename the frozen predicate to has_successor to make the semantics of the predicate more clear to outside callers. In the process, remove some calls to frozen() that no longer semantically make sense. For bdrv_enable_dirty_bitmap_locked and bdrv_disable_dirty_bitmap_locked, it doesn't make sense to prohibit QEMU internals from performing this action when we only wished to prohibit QMP users from issuing these commands. All of the QMP API commands for bitmap manipulation already check against user_locked() to prohibit these actions. Several other assertions really want to check that the bitmap isn't in-use by another operation -- use the bitmap_user_locked function for this instead, which presently also checks for has_successor. This leaves some redundant checks of has_successor through different helpers that are addressed in forthcoming patches. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190223000614.13894-3-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12block/dirty-bitmap: add recording and busy propertiesJohn Snow1-0/+9
The current API allows us to report a single status, which we've defined as: Frozen: has a successor, treated as qmp_locked, may or may not be enabled. Locked: no successor, qmp_locked. may or may not be enabled. Disabled: Not frozen or locked, disabled. Active: Not frozen, locked, or disabled. The problem is that both "Frozen" and "Locked" mean nearly the same thing, and that both of them do not intuit whether they are recording guest writes or not. This patch deprecates that status field and introduces two orthogonal properties instead to replace it. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190223000614.13894-2-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-02-19block/dirty-bitmap: Documentation and Comment fixupsJohn Snow1-6/+14
The meaning of the states has changed subtly over time, this should bring the understanding more in-line with the current, actual usages. Reported-by: Eric Blake <eblake@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190202011048.12343-1-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-02-19dirty-bitmap: Expose persistent flag to 'query-block'Eric Blake1-0/+1
Since qemu currently doesn't flush persistent bitmaps to disk until shutdown (which might be MUCH later), it's useful if 'query-block' at least shows WHICH bitmaps will (eventually) make it to persistent storage. Update affected iotests. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190204210512.27458-1-eblake@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-01-15Revert "hbitmap: Add @advance param to hbitmap_iter_next()"Vladimir Sementsov-Ogievskiy1-1/+1
This reverts commit a33fbb4f8b64226becf502a123733776ce319b24. The functionality is unused. Note: in addition to automatic revert, drop second parameter in hbitmap_iter_next() call from hbitmap_next_dirty_area() too. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com>
2019-01-15Revert "block/dirty-bitmap: Add bdrv_dirty_iter_next_area"Vladimir Sementsov-Ogievskiy1-55/+0
This reverts commit 72d10a94213a954ad569095cb4491f2ae0853c40. The function is unused now. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com>
2019-01-15dirty-bitmap: add bdrv_dirty_bitmap_next_dirty_areaVladimir Sementsov-Ogievskiy1-0/+6
The function alters bdrv_dirty_iter_next_area(), which is wrong and less efficient (see further commit "block/mirror: fix and improve do_sync_target_write" for description). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-15dirty-bitmap: improve bdrv_dirty_bitmap_next_zeroVladimir Sementsov-Ogievskiy1-2/+3
Add bytes parameter to the function, to limit searched range. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-14block/dirty-bitmap: remove assertion from restoreJohn Snow1-1/+0
When making a backup of a dirty bitmap (for transactions), we want to restore that backup whether or not the bitmap is enabled. It is perfectly valid to write into bitmaps that are disabled. It is only illegitimate for the guest to have done so. Remove this assertion. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: John Snow <jsnow@redhat.com> Message-Id: <20181221093529.23855-3-jsnow@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2018-10-29dirty-bitmaps: clean-up bitmaps loading and migration logicVladimir Sementsov-Ogievskiy1-22/+14
This patch aims to bring the following behavior: 1. We don't load bitmaps, when started in inactive mode. It's the case of incoming migration. In this case we wait for bitmaps migration through migration channel (if 'dirty-bitmaps' capability is enabled) or for invalidation (to load bitmaps from the image). 2. We don't remove persistent bitmaps on inactivation. Instead, we only remove bitmaps after storing. This is the only way to restore bitmaps, if we decided to resume source after [failed] migration with 'dirty-bitmaps' capability enabled (which means, that bitmaps were not stored). 3. We load bitmaps on open and any invalidation, it's ok for all cases: - normal open - migration target invalidation with dirty-bitmaps capability (bitmaps are migrating through migration channel, the are not stored, so they should have IN_USE flag set and will be skipped when loading. However, it would fail if bitmaps are read-only[1]) - migration target invalidation without dirty-bitmaps capability (normal load of the bitmaps, if migrated with shared storage) - source invalidation with dirty-bitmaps capability (skip because IN_USE) - source invalidation without dirty-bitmaps capability (bitmaps were dropped, reload them) [1]: to accurately handle this, migration of read-only bitmaps is explicitly forbidden in this patch. New mechanism for not storing bitmaps when migrate with dirty-bitmaps capability is introduced: migration filed in BdrvDirtyBitmap. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: John Snow <jsnow@redhat.com>
2018-10-29block/dirty-bitmaps: allow clear on disabled bitmapsJohn Snow1-1/+0
Similarly to merge, it's OK to allow clear operations on disabled bitmaps, as this condition only means that they are not recording new writes. We are free to clear it if the user requests it. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20181002230218.13949-4-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2018-10-29block/dirty-bitmaps: fix merge permissionsJohn Snow1-3/+3
In prior commits that made merge transactionable, we removed the assertion that merge cannot operate on disabled bitmaps. In addition, we want to make sure that we are prohibiting merges to "locked" bitmaps. Use the new user_locked function to check. Reported-by: Eric Blake <eblake@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20181002230218.13949-3-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>
2018-10-29block/dirty-bitmaps: add user_locked status checkerJohn Snow1-0/+6
Instead of both frozen and qmp_locked checks, wrap it into one check. frozen implies the bitmap is split in two (for backup), and shouldn't be modified. qmp_locked implies it's being used by another operation, like being exported over NBD. In both cases it means we shouldn't allow the user to modify it in any meaningful way. Replace any usages where we check both frozen and qmp_locked with the new check. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20181002230218.13949-2-jsnow@redhat.com [w/edits Suggested-By: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>] Signed-off-by: John Snow <jsnow@redhat.com>
2018-10-29dirty-bitmap: make it possible to restore bitmap after mergeVladimir Sementsov-Ogievskiy1-3/+14
Add backup parameter to bdrv_merge_dirty_bitmap() to be used then with bdrv_restore_dirty_bitmap() if it needed to restore the bitmap after merge operation. This is needed to implement bitmap merge transaction action in further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com>
2018-10-29dirty-bitmap: rename bdrv_undo_clear_dirty_bitmapVladimir Sementsov-Ogievskiy1-2/+2
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>
2018-10-29dirty-bitmap: switch assert-fails to errors in bdrv_merge_dirty_bitmapVladimir Sementsov-Ogievskiy1-2/+13
Move checks from qmp_x_block_dirty_bitmap_merge() to bdrv_merge_dirty_bitmap(), to share them with dirty bitmap merge transaction action in future commit. Note: for now, only qmp_x_block_dirty_bitmap_merge() calls bdrv_merge_dirty_bitmap(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com>
2018-07-04dirty-bitmap: fix double lock on bitmap enablingVladimir Sementsov-Ogievskiy1-1/+2
Bitmap lock/unlock were added to bdrv_enable_dirty_bitmap in 8b1402ce80d, but some places were not updated correspondingly, which leads to trying to take this lock twice, which is dead-lock. Fix this. Actually, iotest 199 (about dirty bitmap postcopy migration) is broken now, and this fixes it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20180625165745.25259-3-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2018-07-04block/dirty-bitmap: add bdrv_enable_dirty_bitmap_lockedVladimir Sementsov-Ogievskiy1-2/+7
Add _locked version of bdrv_enable_dirty_bitmap, to fix dirty bitmap migration in the following patch. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20180625165745.25259-2-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2018-06-18block/dirty-bitmap: Add bdrv_dirty_iter_next_areaMax Reitz1-0/+55
This new function allows to look for a consecutively dirty area in a dirty bitmap. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20180613181823.13618-10-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-18hbitmap: Add @advance param to hbitmap_iter_next()Max Reitz1-1/+1
This new parameter allows the caller to just query the next dirty position without moving the iterator. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20180613181823.13618-8-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11qapi: add x-block-dirty-bitmap-mergeVladimir Sementsov-Ogievskiy1-0/+18
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20180606182449.1607-5-jsnow@redhat.com Signed-off-by: John Snow <jsnow@redhat.com>