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2020-06-17qcow2: Tweak comments on qcow2_get_persistent_dirty_bitmap_sizeEric Blake
For now, we don't have persistent bitmaps in any other formats, but that might not be true in the future. Make it obvious that our incoming parameter is not necessarily a qcow2 image, and therefore is limited to just the bdrv_dirty_bitmap_* API calls (rather than probing into qcow2 internals). Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200608190821.3293867-1-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-28qcow2: Expose bitmaps' size during measureEric Blake
It's useful to know how much space can be occupied by qcow2 persistent bitmaps, even though such metadata is unrelated to the guest-visible data. Report this value as an additional QMP field, present when measuring an existing image and output format that both support bitmaps. Update iotest 178 and 190 to updated output, as well as new coverage in 190 demonstrating non-zero values made possible with the recently-added qemu-img bitmap command (see 3b51ab4b). The new 'bitmaps size:' field is displayed automatically as part of 'qemu-img measure' any time it is present in QMP (that is, any time both the source image being measured and destination format support bitmaps, even if the measurement is 0 because there are no bitmaps present). If the field is absent, it means that no bitmaps can be copied (source, destination, or both lack bitmaps, including when measuring based on size rather than on a source image). This behavior is compatible with an upcoming patch adding 'qemu-img convert --bitmaps': that command will fail in the same situations where this patch omits the field. The addition of a new field demonstrates why we should always zero-initialize qapi C structs; while the qcow2 driver still fully populates all fields, the raw and crypto drivers had to be tweaked to avoid uninitialized data. Consideration was also given towards having a 'qemu-img measure --bitmaps' which errors out when bitmaps are not possible, and otherwise sums the bitmaps into the existing allocation totals rather than displaying as a separate field, as a potential convenience factor. But this was ultimately decided to be more complexity than necessary when the QMP interface was sufficient enough with bitmaps remaining a separate field. See also: https://bugzilla.redhat.com/1779904 Reported-by: Nir Soffer <nsoffer@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200521192137.1120211-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-19block: Make it easier to learn which BDS support bitmapsEric Blake
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/qcow2-bitmap: use bdrv_dirty_bitmap_next_dirtyVladimir Sementsov-Ogievskiy
store_bitmap_data() loop does bdrv_set_dirty_iter() on each iteration, which means that we actually don't need iterator itself and we can use simpler bitmap API. 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: 20200205112041.6003-11-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2020-02-18block/qcow2-bitmap: Remove unneeded variable assignmentPhilippe Mathieu-Daudé
Fix warning reported by Clang static code analyzer: CC block/qcow2-bitmap.o block/qcow2-bitmap.c:650:5: warning: Value stored to 'ret' is never read ret = -EINVAL; ^ ~~~~~~~ Fixes: 88ddffae8 Reported-by: Clang Static Analyzer Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20200215161557.4077-2-philmd@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Ján Tomko <jtomko@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-06qcow2-bitmaps: fix qcow2_can_store_new_dirty_bitmapVladimir Sementsov-Ogievskiy
qcow2_can_store_new_dirty_bitmap works wrong, as it considers only bitmaps already stored in the qcow2 image and ignores persistent BdrvDirtyBitmap objects. So, let's instead count persistent BdrvDirtyBitmaps. We load all qcow2 bitmaps on open, so there should not be any bitmap in the image for which we don't have BdrvDirtyBitmaps version. If it is - it's a kind of corruption, and no reason to check for corruptions here (open() and close() are better places for it). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20191014115126.15360-2-vsementsov@virtuozzo.com Reviewed-by: Max Reitz <mreitz@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-12-09block/qcow2-bitmap: fix crash bug in qcow2_co_remove_persistent_dirty_bitmapVladimir Sementsov-Ogievskiy
Here is double bug: First, return error but not set errp. This may lead to: qmp block-dirty-bitmap-remove may report success when actually failed block-dirty-bitmap-remove used in a transaction will crash, as qmp_transaction will think that it returned success and will call block_dirty_bitmap_remove_commit which will crash, as state->bitmap is NULL Second (like in anecdote), this case is not an error at all. As it is documented in the comment above bdrv_co_remove_persistent_dirty_bitmap definition, absence of bitmap is not an error, and similar case handled at start of qcow2_co_remove_persistent_dirty_bitmap, it returns 0 when there is no bitmaps at all. But when there are some bitmaps, but not the requested one, it return error with errp unset. Fix that. Trigger: 1. create persistent bitmap A 2. shutdown vm (bitmap A is synced) 3. start vm 4. create persistent bitmap B 5. remove bitmap B - it fails (and crashes if in transaction) Potential workaround (rather invasive to ask clients to implement it): 1. create persistent bitmap A 2. shutdown vm 3. start vm 4. create persistent bitmap B 5. remember, that we want to remove bitmap B after vm shutdown ... some other operations ... 6. vm shutdown 7. start vm in stopped mode, and remove all bitmaps marked for removing 8. stop vm Fixes: b56a1e31759b750 Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20191205193049.30666-1-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> [eblake: commit message tweaks] Signed-off-by: Eric Blake <eblake@redhat.com>
2019-11-26block/qcow2-bitmap: fix bitmap migrationVladimir Sementsov-Ogievskiy
Fix bitmap migration with dirty-bitmaps capability enabled and shared storage. We should ignore IN_USE bitmaps in the image on target, when migrating bitmaps through migration channel, see new comment below. Fixes: 74da6b943565c451 Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20191125125229.13531-2-vsementsov@virtuozzo.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-18bitmap: Enforce maximum bitmap name lengthEric Blake
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>
2019-11-07qcow2-bitmap: Fix uint64_t left-shift overflowTuguoyi
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: 5f72826e7fc62167cf3a 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>
2019-10-17block/qcow2-bitmap: fix and improve qcow2_reopen_bitmaps_rwVladimir Sementsov-Ogievskiy
- 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>
2019-10-17block/qcow2-bitmap: do not remove bitmaps on reopen-roVladimir Sementsov-Ogievskiy
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>
2019-10-17block/qcow2-bitmap: drop qcow2_reopen_bitmaps_rw_hint()Vladimir Sementsov-Ogievskiy
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>
2019-10-17block/qcow2-bitmap: get rid of bdrv_has_changed_persistent_bitmapsVladimir Sementsov-Ogievskiy
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-Ogievskiy
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: add bs linkVladimir Sementsov-Ogievskiy
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/qcow2: proper locking on bitmap add/remove pathsVladimir Sementsov-Ogievskiy
qmp_block_dirty_bitmap_add and do_block_dirty_bitmap_remove do acquire aio context since 0a6c86d024c52b. But this is not enough: we also must lock qcow2 mutex when access in-image metadata. Especially it concerns freeing qcow2 clusters. To achieve this, move qcow2_can_store_new_dirty_bitmap and qcow2_remove_persistent_dirty_bitmap to coroutine context. Since we work in coroutines in correct aio context, we don't need context acquiring in blockdev.c anymore, drop it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190920082543.23444-4-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17block/dirty-bitmap: return int from bdrv_remove_persistent_dirty_bitmapVladimir Sementsov-Ogievskiy
It's more comfortable to not deal with local_err. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20190920082543.23444-3-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-05-28qcow2-bitmap: initialize bitmap directory alignmentAndrey Shinkevich
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>
2019-05-28qcow2.h: add missing includeVladimir Sementsov-Ogievskiy
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>
2019-05-07qcow2: discard bitmap when removedAndrey Shinkevich
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>
2019-03-12block/qcow2-bitmap: Allow resizes with persistent bitmapsJohn Snow
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>
2019-03-12block/qcow2-bitmap: Don't check size for IN_USE bitmapVladimir Sementsov-Ogievskiy
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>
2019-03-12bitmaps: Fix typo in function nameEric Blake
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: implement inconsistent bitJohn Snow
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>
2019-03-08qcow2: External file I/OKevin Wolf
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>
2019-02-11qcow2: Add list of bitmaps to ImageInfoSpecificQCow2Andrey Shinkevich
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>
2019-01-11qemu/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>
2018-11-05block/qcow2-bitmap: Don't take address of fields in packed structsPeter Maydell
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>
2018-10-29dirty-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>
2018-07-09qcow2: add overlap check for bitmap directoryVladimir Sementsov-Ogievskiy
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>
2018-06-11block/qcow2-bitmap: fix free_bitmap_clustersVladimir Sementsov-Ogievskiy
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>
2018-05-31block: 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: Philippe Mathieu-Daudé <f4bug@amsat.org> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-03-26qcow2-bitmap: add qcow2_reopen_bitmaps_rw_hint()Vladimir Sementsov-Ogievskiy
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>
2018-03-09qcow2: fix flushing after dirty bitmap metadata writesPaolo Bonzini
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>
2018-03-02qcow2: Replace align_offset() with ROUND_UP()Alberto Garcia
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>
2018-02-13block: maintain persistent disabled bitmapsVladimir Sementsov-Ogievskiy
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>
2018-01-23qcow2: No persistent dirty bitmaps for compat=0.10Max Reitz
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>
2017-10-06qcow2: Switch store_bitmap_data() to byte-based iterationEric Blake
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>
2017-10-06qcow2: Switch load_bitmap_data() to byte-based iterationEric Blake
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>
2017-10-06dirty-bitmap: Change bdrv_dirty_iter_next() to report byte offsetEric Blake
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>
2017-10-06dirty-bitmap: Set iterator start by offset, not sectorEric Blake
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>
2017-10-06qcow2: Switch sectors_covered_by_bitmap_cluster() to byte-basedEric Blake
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>
2017-10-06dirty-bitmap: Change bdrv_dirty_bitmap_*serialize*() to take bytesEric Blake
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>
2017-10-06dirty-bitmap: Change bdrv_dirty_bitmap_size() to report bytesEric Blake
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>
2017-10-06qcow2: Ensure bitmap serialization is alignedEric Blake
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>
2017-09-26block/qcow2-bitmap: fix use of uninitialized pointerVladimir Sementsov-Ogievskiy
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>
2017-07-25qcow2-bitmap: fix bitmap_freeVladimir Sementsov-Ogievskiy
Fix possible crash on error path in qcow2_remove_persistent_dirty_bitmap. Although bitmap_free was added in 88ddffae8fc the bug was introduced later in commit 469c71edc72 (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>
2017-07-11qcow2: add .bdrv_remove_persistent_dirty_bitmapVladimir Sementsov-Ogievskiy
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>
2017-07-11qcow2: add .bdrv_can_store_new_dirty_bitmapVladimir Sementsov-Ogievskiy
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>