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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
"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>
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>
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>
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>
This reverts commit a33fbb4f8b.
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>
This reverts commit 72d10a9421.
The function is unused now.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Bitmap lock/unlock were added to bdrv_enable_dirty_bitmap in
8b1402ce80, 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>
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>
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>
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>
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>
Add locks and remove comments about BQL accordingly to
dirty_bitmap_mutex definition in block_int.h.
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: 20180606182449.1607-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
QLIST_REMOVE does not require walking the list, and once the "bitmap"
argument is removed from bdrv_do_release_matching_dirty_bitmap_locked
the code simplifies a lot and it is worth inlining everything in the
callers of bdrv_do_release_matching_dirty_bitmap.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180326104037.6894-1-pbonzini@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
All this function is doing will be repeated by
bdrv_do_release_matching_dirty_bitmap_locked, except
resetting bm->persistent. But even that does not matter
because the bitmap will be freed.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180323164254.26487-1-pbonzini@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Add special state, when qmp operations on the bitmap are disabled.
It is needed during bitmap migration. "Frozen" state is not
appropriate here, because it looks like bitmap is unchanged.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-5-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-4-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Like other setters here these functions should take a lock.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-3-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Enabling bitmap successor is necessary to enable successors of bitmaps
being migrated before target vm start.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180207155837.92351-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
To maintain load/store disabled bitmap there is new approach:
- deprecate @autoload flag of block-dirty-bitmap-add, make it ignored
- store enabled bitmaps as "auto" to qcow2
- store disabled bitmaps without "auto" flag to qcow2
- on qcow2 open load "auto" bitmaps as enabled and others
as disabled (except in_use bitmaps)
Also, adjust iotests 165 and 176 appropriately.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180202160752.143796-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
The function searches for next zero bit.
Also add interface for BdrvDirtyBitmap and unit test.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20171012135313.227864-2-vsementsov@virtuozzo.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
Now that all callers are using byte-based interfaces, there's no
reason for our internal hbitmap to remain with sector-based
granularity. It also simplifies our internal scaling, since we
already know that hbitmap widens requests out to granularity
boundaries.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Both callers already had bytes available, but were scaling to
sectors. Move the scaling to internal code. In the case of
bdrv_aligned_pwritev(), we are now passing the exact offset
rather than a rounded sector-aligned value, but that's okay
as long as dirty bitmap widens start/bytes to granularity
boundaries.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Some of the callers were already scaling bytes to sectors; others
can be easily converted to pass byte offsets, all in our shift
towards a consistent byte interface everywhere. Making the change
will also make it easier to write the hold-out callers to use byte
rather than sectors for their iterations; it also makes it easier
for a future dirty-bitmap patch to offload scaling over to the
internal hbitmap. Although all callers happen to pass
sector-aligned values, make the internal scaling robust to any
sub-sector requests.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Half the callers were already scaling bytes to sectors; the other
half can eventually be simplified to use byte iteration. Both
callers were already using the result as a bool, so make that
explicit. Making the change also makes it easier for a future
dirty-bitmap patch to offload scaling over to the internal hbitmap.
Remember, asking whether a byte is dirty is effectively asking
whether the entire granularity containing the byte is dirty, since
we only track dirtiness by granularity.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Thanks to recent cleanups, all callers were scaling a return value
of sectors into bytes; do the scaling internally instead.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Thanks to recent cleanups, most callers were scaling a return value
of sectors into bytes (the exception, in qcow2-bitmap, will be
converted to byte-based iteration later). Update the interface to
do the scaling internally instead.
In qcow2-bitmap, the code was specifically checking for an error
return of -1. To avoid a regression, we either have to make sure
we continue to return -1 (rather than a scaled -512) on error, or
we have to fix the caller to treat all negative values as error
rather than just one magic value. It's easy enough to make both
changes at the same time, even though either one in isolation
would work.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
All callers to bdrv_dirty_iter_new() passed 0 for their initial
starting point, drop that parameter.
Most callers to bdrv_set_dirty_iter() were scaling a byte offset to
a sector number; the exception qcow2-bitmap will be converted later
to use byte rather than sector iteration. Move the scaling to occur
internally to dirty bitmap code instead, so that callers now pass
in bytes.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Right now, the dirty-bitmap code exposes the fact that we use
a scale of sector granularity in the underlying hbitmap to anything
that wants to serialize a dirty bitmap. It's nicer to uniformly
expose bytes as our dirty-bitmap interface, matching the previous
change to bitmap size. The only caller to serialization is currently
qcow2-cluster.c, which becomes a bit more verbose because it is still
tracking sectors for other reasons, but a later patch will fix that
to more uniformly use byte offsets everywhere. Likewise, within
dirty-bitmap, we have to add more assertions that we are not
truncating incorrectly, which can go away once the internal hbitmap
is byte-based rather than sector-based.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are still using an internal hbitmap that tracks a size in sectors,
with the granularity scaled down accordingly, because it lets us
use a shortcut for our iterators which are currently sector-based.
But there's no reason we can't track the dirty bitmap size in bytes,
since it is (mostly) an internal-only variable (remember, the size
is how many bytes are covered by the bitmap, not how many bytes the
bitmap occupies). A later cleanup will convert dirty bitmap
internals to be entirely byte-based, eliminating the intermediate
sector rounding added here; and technically, since bdrv_getlength()
already rounds up to sectors, our use of DIV_ROUND_UP is more for
theoretical completeness than for any actual rounding.
Use is_power_of_2() while at it, instead of open-coding that.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We're already reporting bytes for bdrv_dirty_bitmap_granularity();
mixing bytes and sectors in our return values is a recipe for
confusion. A later cleanup will convert dirty bitmap internals
to be entirely byte-based, but in the meantime, we should report
the bitmap size in bytes.
The only external caller in qcow2-bitmap.c is temporarily more verbose
(because it is still using sector-based math), but will later be
switched to track progress by bytes instead of sectors.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
