Commit Graph

49 Commits

Author SHA1 Message Date
Eric Blake
cf7c49cf6a bitmap: Enforce maximum bitmap name length
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>
2019-11-18 16:01:34 -06:00
Tuguoyi
570542ecb1 qcow2-bitmap: Fix uint64_t left-shift overflow
There are two issues in In check_constraints_on_bitmap(),
1) The sanity check on the granularity will cause uint64_t
integer left-shift overflow when cluster_size is 2M and the
granularity is BIGGER than 32K.
2) The way to calculate image size that the maximum bitmap
supported can map to is a bit incorrect.
This patch fix it by add a helper function to calculate the
number of bytes needed by a normal bitmap in image and compare
it to the maximum bitmap bytes supported by qemu.

Fixes: 5f72826e7f
Signed-off-by: Guoyi Tu <tu.guoyi@h3c.com>
Message-id: 4ba40cd1e7ee4a708b40899952e49f22@h3c.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-07 14:37:33 +01:00
Vladimir Sementsov-Ogievskiy
f6333cbf8b block/qcow2-bitmap: fix and improve qcow2_reopen_bitmaps_rw
- Correct check for write access to file child, and in correct place
  (only if we want to write).
- Support reopen rw -> rw (which will be used in following commit),
  for example, !bdrv_dirty_bitmap_readonly() is not a corruption if
  bitmap is marked IN_USE in the image.
- Consider unexpected bitmap as a corruption and check other
  combinations of in-image and in-RAM bitmaps.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190927122355.7344-9-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17 17:53:28 -04:00
Vladimir Sementsov-Ogievskiy
644ddbb754 block/qcow2-bitmap: do not remove bitmaps on reopen-ro
qcow2_reopen_bitmaps_ro wants to store bitmaps and then mark them all
readonly. But the latter don't work, as
qcow2_store_persistent_dirty_bitmaps removes bitmaps after storing.
It's OK for inactivation but bad idea for reopen-ro. And this leads to
the following bug:

Assume we have persistent bitmap 'bitmap0'.
Create external snapshot
  bitmap0 is stored and therefore removed
Commit snapshot
  now we have no bitmaps
Do some writes from guest (*)
  they are not marked in bitmap
Shutdown
Start
  bitmap0 is loaded as valid, but it is actually broken! It misses
  writes (*)
Incremental backup
  it will be inconsistent

So, let's stop removing bitmaps on reopen-ro. But don't rejoice:
reopening bitmaps to rw is broken too, so the whole scenario will not
work after this patch and we can't enable corresponding test cases in
260 iotests still. Reopening bitmaps rw will be fixed in the following
patches.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190927122355.7344-7-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
bd429a884c block/qcow2-bitmap: drop qcow2_reopen_bitmaps_rw_hint()
The function is unused, drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190927122355.7344-6-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
f88676c149 block/qcow2-bitmap: get rid of bdrv_has_changed_persistent_bitmaps
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>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
ef9041a7b8 block/dirty-bitmap: refactor bdrv_dirty_bitmap_next
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>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
5deb6cbd1f block/dirty-bitmap: add bs link
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>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
d2c3080e41 block/qcow2: proper locking on bitmap add/remove paths
qmp_block_dirty_bitmap_add and do_block_dirty_bitmap_remove do acquire
aio context since 0a6c86d024. 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>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
b56a1e3175 block/dirty-bitmap: return int from bdrv_remove_persistent_dirty_bitmap
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>
2019-10-17 17:02:32 -04:00
Andrey Shinkevich
6388903e7c qcow2-bitmap: initialize bitmap directory alignment
Valgrind detects multiple issues in QEMU iotests when the memory is
used without being initialized. Valgrind may dump lots of unnecessary
reports what makes the memory issue analysis harder. Particularly,
that is true for the aligned bitmap directory and can be seen while
running the iotest #169. Padding the aligned space with zeros eases
the pain.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Message-id: 1558961521-131620-1-git-send-email-andrey.shinkevich@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-05-28 20:30:55 +02:00
Vladimir Sementsov-Ogievskiy
9353db47c5 qcow2.h: add missing include
qcow2.h depends on block_int.h. Compilation isn't broken currently only
due to block_int.h always included before qcow2.h. Though, it seems
better to directly include block_int.h in qcow2.h.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190506142741.41731-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-05-28 20:30:55 +02:00
Andrey Shinkevich
444b82369b qcow2: discard bitmap when removed
Bitmap data may take a lot of disk space, so it's better to discard it
always.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Message-id: 1551346019-293202-1-git-send-email-andrey.shinkevich@virtuozzo.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[mreitz: Use the commit message proposed by Vladimir]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-05-07 17:14:21 +02:00
John Snow
d19c6b36ff block/qcow2-bitmap: Allow resizes with persistent bitmaps
Since we now load all bitmaps into memory anyway, we can just truncate
them in-memory and then flush them back to disk. Just in case, we will
still check and enforce that this shortcut is valid -- i.e. that any
bitmap described on-disk is indeed in-memory and can be modified.

If there are any inconsistent bitmaps, we refuse to allow the truncate
as we do not actually load these bitmaps into memory, and it isn't safe
or reasonable to attempt to truncate corrupted data.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190311185147.52309-4-vsementsov@virtuozzo.com
  [vsementsov: drop bitmap flushing, fix block comments style]
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 14:57:38 -04:00
Vladimir Sementsov-Ogievskiy
bf5f0cf5d8 block/qcow2-bitmap: Don't check size for IN_USE bitmap
We are going to allow image resize when there are persistent bitmaps.
It may lead to appearing of inconsistent bitmaps (IN_USE=1) with
inconsistent size. But we still want to load them as inconsistent.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190311185147.52309-3-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 14:50:28 -04:00
Eric Blake
796a3798ab bitmaps: Fix typo in function name
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>
2019-03-12 12:05:49 -04:00
John Snow
74da6b9435 block/dirty-bitmaps: implement inconsistent bit
Set the inconsistent bit on load instead of rejecting such bitmaps.
There is no way to un-set it; the only option is to delete the bitmap.

Obvervations:
- bitmap loading does not need to update the header for in_use bitmaps.
- inconsistent bitmaps don't need to have their data loaded; they're
  glorified corruption sentinels.
- bitmap saving does not need to save inconsistent bitmaps back to disk.
- bitmap reopening DOES need to drop the readonly flag from inconsistent
  bitmaps to allow reopening of qcow2 files with non-qemu-owned bitmaps
  being eventually flushed back to disk.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20190301191545.8728-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:49 -04:00
Kevin Wolf
966b000f49 qcow2: External file I/O
This changes the qcow2 implementation to direct all guest data I/O to
s->data_file rather than bs->file, while metadata I/O still uses
bs->file. At the moment, this is still always the same, but soon we'll
add options to set s->data_file to an external data file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:46 +01:00
Andrey Shinkevich
b8968c875f qcow2: Add list of bitmaps to ImageInfoSpecificQCow2
In the 'Format specific information' section of the 'qemu-img info'
command output, the supplemental information about existing QCOW2
bitmaps will be shown, such as a bitmap name, flags and granularity:

image: /vz/vmprivate/VM1/harddisk.hdd
file format: qcow2
virtual size: 64G (68719476736 bytes)
disk size: 3.0M
cluster_size: 1048576
Format specific information:
    compat: 1.1
    lazy refcounts: true
    bitmaps:
        [0]:
            flags:
                [0]: in-use
                [1]: auto
            name: back-up1
            granularity: 65536
        [1]:
            flags:
                [0]: in-use
                [1]: auto
            name: back-up2
            granularity: 65536
    refcount bits: 16
    corrupt: false

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1549638368-530182-3-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-11 14:35:43 -06:00
Paolo Bonzini
b58deb344d qemu/queue.h: leave head structs anonymous unless necessary
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>
2019-01-11 15:46:55 +01:00
Peter Maydell
caacea4b2e block/qcow2-bitmap: Don't take address of fields in packed structs
Taking the address of a field in a packed struct is a bad idea, because
it might not be actually aligned enough for that pointer type (and
thus cause a crash on dereference on some host architectures). Newer
versions of clang warn about this. Avoid the bug by not using the
"modify in place" byte swapping functions.

There are a few places where the in-place swap function is
used on something other than a packed struct field; we convert
those anyway, for consistency.

This patch was produced with the following spatch script:

@@
expression E;
@@
-be16_to_cpus(&E);
+E = be16_to_cpu(E);
@@
expression E;
@@
-be32_to_cpus(&E);
+E = be32_to_cpu(E);
@@
expression E;
@@
-be64_to_cpus(&E);
+E = be64_to_cpu(E);
@@
expression E;
@@
-cpu_to_be16s(&E);
+E = cpu_to_be16(E);
@@
expression E;
@@
-cpu_to_be32s(&E);
+E = cpu_to_be32(E);
@@
expression E;
@@
-cpu_to_be64s(&E);
+E = cpu_to_be64(E);

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: John Snow <jsnow@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-11-05 15:09:54 +01:00
Vladimir Sementsov-Ogievskiy
9c98f145df dirty-bitmaps: clean-up bitmaps loading and migration logic
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>
2018-10-29 16:23:17 -04:00
Vladimir Sementsov-Ogievskiy
0e4e4318ea qcow2: add overlap check for bitmap directory
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180705151515.779173-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-07-09 19:43:24 +02:00
Vladimir Sementsov-Ogievskiy
7eb24009db block/qcow2-bitmap: fix free_bitmap_clusters
This assert may fail, because bitmap_table is not initialized. Just
drop it, as it's obvious, that bitmap_table_load sets bitmap_table
parameter only when returning zero.

Reported-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180608101225.2575-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11 16:18:45 +02:00
Michael S. Tsirkin
0d8c41dae5 block: use local path for local headers
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: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-05-31 04:16:06 +03:00
Vladimir Sementsov-Ogievskiy
b1336cc2ec qcow2-bitmap: add qcow2_reopen_bitmaps_rw_hint()
Add version of qcow2_reopen_bitmaps_rw, which do the same work but
also return a hint about was header updated or not. This will be
used in the following fix for bitmaps reloading after migration.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180320170521.32152-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-03-26 21:17:24 +02:00
Paolo Bonzini
1a0c2bfb03 qcow2: fix flushing after dirty bitmap metadata writes
update_header_sync itself does not need to flush the caches to disk.
The only paths that allocate clusters are:

- bitmap_list_store with in_place=false, called by update_ext_header_and_dir

- store_bitmap_data, called by store_bitmap

- store_bitmap, called by qcow2_store_persistent_dirty_bitmaps and
  followed by update_ext_header_and_dir

So in the end the central place where we need to flush the caches
is update_ext_header_and_dir.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-09 15:17:47 +01:00
Alberto Garcia
9e029689e1 qcow2: Replace align_offset() with ROUND_UP()
The align_offset() function is equivalent to the ROUND_UP() macro so
there's no need to use the former. The ROUND_UP() name is also a bit
more explicit.

This patch uses ROUND_UP() instead of the slower QEMU_ALIGN_UP()
because align_offset() already requires that the second parameter is a
power of two.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180215131008.5153-1-berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-03-02 18:39:56 +01:00
Vladimir Sementsov-Ogievskiy
3e99da5e76 block: maintain persistent disabled bitmaps
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>
2018-02-13 16:59:58 +01:00
Max Reitz
c9ceb3ec8a qcow2: No persistent dirty bitmaps for compat=0.10
Persistent dirty bitmaps require a properly functioning
autoclear_features field, or we cannot track when an unsupporting
program might overwrite them.  Therefore, we cannot support them for
compat=0.10 images.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171123020832.8165-3-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-01-23 12:34:42 +01:00
Eric Blake
49d741b504 qcow2: Switch store_bitmap_data() to byte-based iteration
Now that we have adjusted the majority of the calls this function
makes to be byte-based, it is easier to read the code if it makes
passes over the image using bytes rather than sectors.

iotests 165 was rather weak - on a default 64k-cluster image, where
bitmap granularity also defaults to 64k bytes, a single cluster of
the bitmap table thus covers (64*1024*8) bits which each cover 64k
bytes, or 32G of image space.  But the test only uses a 1G image,
so it cannot trigger any more than one loop of the code in
store_bitmap_data(); and it was writing to the first cluster.  In
order to test that we are properly aligning which portions of the
bitmap are being written to the file, we really want to test a case
where the first dirty bit returned by bdrv_dirty_iter_next() is not
aligned to the start of a cluster, which we can do by modifying the
test to write data that doesn't happen to fall in the first cluster
of the image.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
ab94db6f76 qcow2: Switch load_bitmap_data() to byte-based iteration
Now that we have adjusted the majority of the calls this function
makes to be byte-based, it is easier to read the code if it makes
passes over the image using bytes rather than sectors.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
f798184cfd dirty-bitmap: Change bdrv_dirty_iter_next() to report byte offset
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>
2017-10-06 16:28:58 +02:00
Eric Blake
715a74d819 dirty-bitmap: Set iterator start by offset, not sector
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>
2017-10-06 16:28:58 +02:00
Eric Blake
c7e7c87ac8 qcow2: Switch sectors_covered_by_bitmap_cluster() to byte-based
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Change the qcow2 bitmap
helper function sectors_covered_by_bitmap_cluster(), renaming it
to bytes_covered_by_bitmap_cluster() in the process.

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>
2017-10-06 16:28:58 +02:00
Eric Blake
86f6ae67e1 dirty-bitmap: Change bdrv_dirty_bitmap_*serialize*() to take bytes
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>
2017-10-06 16:28:58 +02:00
Eric Blake
ebfcd2e75f dirty-bitmap: Change bdrv_dirty_bitmap_size() to report bytes
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>
2017-10-06 16:28:58 +02:00
Eric Blake
113754f3a8 qcow2: Ensure bitmap serialization is aligned
When subdividing a bitmap serialization, the code in hbitmap.c
enforces that start/count parameters are aligned (except that
count can end early at end-of-bitmap).  We exposed this required
alignment through bdrv_dirty_bitmap_serialization_align(), but
forgot to actually check that we comply with it.

Fortunately, qcow2 is never dividing bitmap serialization smaller
than one cluster (which is a minimum of 512 bytes); so we are
always compliant with the serialization alignment (which insists
that we partition at least 64 bits per chunk) because we are doing
at least 4k bits per chunk.

Still, it's safer to add an assertion (for the unlikely case that
we'd ever support a cluster smaller than 512 bytes, or if the
hbitmap implementation changes what it considers to be aligned),
rather than leaving bdrv_dirty_bitmap_serialization_align()
without a caller.

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>
2017-10-06 16:28:58 +02:00
Vladimir Sementsov-Ogievskiy
5330f32b71 block/qcow2-bitmap: fix use of uninitialized pointer
Without initialization to zero dirty_bitmap field may be not zero
for a bitmap which should not be stored and
qcow2_store_persistent_dirty_bitmaps will erroneously call
store_bitmap for it which leads to SIGSEGV on bdrv_dirty_bitmap_name.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170922144353.4220-1-vsementsov@virtuozzo.com
Cc: qemu-stable@nongnu.org
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-09-26 15:00:32 +02:00
Vladimir Sementsov-Ogievskiy
b6b75a99da qcow2-bitmap: fix bitmap_free
Fix possible crash on error path in
qcow2_remove_persistent_dirty_bitmap. Although bitmap_free was added in
88ddffae8f the bug was introduced later in commit 469c71edc7 (when
qcow2_remove_persistent_dirty_bitmap was added).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170714123341.373857-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-25 16:33:31 +02:00
Vladimir Sementsov-Ogievskiy
469c71edc7 qcow2: add .bdrv_remove_persistent_dirty_bitmap
Realize .bdrv_remove_persistent_dirty_bitmap interface.

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: 20170628120530.31251-29-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
da0eb242ad qcow2: add .bdrv_can_store_new_dirty_bitmap
Realize .bdrv_can_store_new_dirty_bitmap interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-23-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
169b879359 qcow2: store bitmaps on reopening image as read-only
Store bitmaps and mark them read-only on reopening image as read-only.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-21-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
5f72826e7f qcow2: add persistent dirty bitmaps support
Store persistent dirty bitmaps in qcow2 image.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-20-vsementsov@virtuozzo.com
[mreitz: Always assign ret in store_bitmap() in case of an error]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
a88b179fdb block: introduce persistent dirty bitmaps
New field BdrvDirtyBitmap.persistent means, that bitmap should be saved
by format driver in .bdrv_close and .bdrv_inactivate. No format driver
supports it for now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170628120530.31251-18-vsementsov@virtuozzo.com
[mreitz: Fixed indentation]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
a0319aacd4 block/dirty-bitmap: add autoload field to BdrvDirtyBitmap
Mirror AUTO flag from Qcow2 bitmap in BdrvDirtyBitmap. This will be
needed in future, to save this flag back to Qcow2 for persistent
bitmaps.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170628120530.31251-16-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
1b6b0562db qcow2: support .bdrv_reopen_bitmaps_rw
Realize bdrv_reopen_bitmaps_rw interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-15-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
d1258dd0c8 qcow2: autoloading dirty bitmaps
Auto loading bitmaps are bitmaps in Qcow2, with the AUTO flag set. They
are loaded when the image is opened and become BdrvDirtyBitmaps for the
corresponding drive.

Extra data in bitmaps is not supported for now.

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: 20170628120530.31251-12-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
88ddffae8f qcow2: add bitmaps extension
Add bitmap extension as specified in docs/specs/qcow2.txt.
For now, just mirror extension header into Qcow2 state and check
constraints. Also, calculate refcounts for qcow2 bitmaps, to not break
qemu-img check.

For now, disable image resize if it has bitmaps. It will be fixed later.

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: 20170628120530.31251-9-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:57 +02:00