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2019-03-12block/dirty-bitmaps: rename frozen predicate helperJohn Snow
"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>
2019-01-11qemu/queue.h: leave head structs anonymous unless necessaryPaolo Bonzini
Most list head structs need not be given a name. In most cases the name is given just in case one is going to use QTAILQ_LAST, QTAILQ_PREV or reverse iteration, but this does not apply to lists of other kinds, and even for QTAILQ in practice this is only rarely needed. In addition, we will soon reimplement those macros completely so that they do not need a name for the head struct. So clean up everything, not giving a name except in the rare case where it is necessary. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-29dirty-bitmaps: clean-up bitmaps loading and migration logicVladimir Sementsov-Ogievskiy
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: add user_locked status checkerJohn Snow
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>
2018-07-04dirty-bitmap: fix double lock on bitmap enablingVladimir Sementsov-Ogievskiy
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>
2018-06-15migration/block-dirty-bitmap: fix dirty_bitmap_loadVladimir Sementsov-Ogievskiy
dirty_bitmap_load_header return code is obtained but not handled. Fix this. Bug was introduced in b35ebdf076d697bc "migration: add postcopy migration of dirty bitmaps" with the whole function. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180530112424.204835-1-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-06-01migration: use local path for local headersMichael S. Tsirkin
When pulling in headers that are in the same directory as the C file (as opposed to one in include/), we should use its relative path, without a directory. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>
2018-05-04migration/block-dirty-bitmap: fix memory leak in dirty_bitmap_load_bitsVladimir Sementsov-Ogievskiy
Release buf on error path too. Bug was introduced in b35ebdf076d697bc "migration: add postcopy migration of dirty bitmaps" with the whole function. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180427142002.21930-3-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-13migration: add postcopy migration of dirty bitmapsVladimir Sementsov-Ogievskiy
Postcopy migration of dirty bitmaps. Only named dirty bitmaps are migrated. If destination qemu is already containing a dirty bitmap with the same name as a migrated bitmap (for the same node), then, if their granularities are the same the migration will be done, otherwise the error will be generated. If destination qemu doesn't contain such bitmap it will be created. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-id: 20180313180320.339796-12-vsementsov@virtuozzo.com [Changed '+' to '*' as per list discussion. --js] Signed-off-by: John Snow <jsnow@redhat.com>