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* block/qcow2-bitmap: return status from qcow2_store_persistent_dirty_bitmapsVladimir Sementsov-Ogievskiy2021-03-081-1/+1
| | | | | | | | | | | | | | | It's better to return status together with setting errp. It makes possible to avoid error propagation. While being here, put ERRP_GUARD() to fix error_prepend(errp, ...) usage inside qcow2_store_persistent_dirty_bitmaps() (see the comment above ERRP_GUARD() definition in include/qapi/error.h) Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Greg Kurz <groug@kaod.org> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20210202124956.63146-11-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block/qcow2-bitmap: improve qcow2_load_dirty_bitmaps() interfaceVladimir Sementsov-Ogievskiy2021-03-081-1/+2
| | | | | | | | | | | | It's recommended for bool functions with errp to return true on success and false on failure. Non-standard interfaces don't help to understand the code. The change is also needed to reduce error propagation. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Greg Kurz <groug@kaod.org> Message-Id: <20210202124956.63146-10-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block/qcow2: qcow2_get_specific_info(): drop error propagationVladimir Sementsov-Ogievskiy2021-03-081-2/+2
| | | | | | | | | | | | Don't use error propagation in qcow2_get_specific_info(). For this refactor qcow2_get_bitmap_info_list, its current interface is rather weird. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210202124956.63146-9-vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> [eblake: separate local 'tail' variable from 'info_list' parameter] Signed-off-by: Eric Blake <eblake@redhat.com>
* block: Fix some code style problems, "foo* bar" should be "foo *bar"shiliyang2020-11-091-3/+3
| | | | | | | | | | There have some code style problems be found when read the block driver code. So I fixes some problems of this error, ERROR: "foo* bar" should be "foo *bar". Signed-off-by: Liyang Shi <shiliyang@huawei.com> Reported-by: Euler Robot <euler.robot@huawei.com> Message-Id: <3211f389-6d22-46c1-4a16-e6a2ba66f070@huawei.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Document and enforce the QCowL2Meta invariantsAlberto Garcia2020-11-091-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The QCowL2Meta structure is used to store information about a part of a write request that touches clusters that need changes in their L2 entries. This happens with newly-allocated clusters or subclusters. This structure has changed a bit since it was first created and its current documentation is not quite up-to-date. A write request can span a region consisting of a combination of clusters of different types, and qcow2_alloc_host_offset() can repeatedly call handle_copied() and handle_alloc() to add more clusters to the mix as long as they all are contiguous on the image file. Because of this a write request has a list of QCowL2Meta structures, one for each part of the request that needs changes in the L2 metadata. Each one of them spans nb_clusters and has two copy-on-write regions located immediately before and after the middle region touched by that part of the write request. Even when those regions themselves are empty their offsets must be correct because they are used to know the location of the middle region. This was not always the case but it is not a problem anymore because the only two places where QCowL2Meta structures are created (calculate_l2_meta() and qcow2_co_truncate()) ensure that the copy-on-write regions are correctly defined, and so do assertions like the ones in perform_cow(). The conditional initialization of the 'written_to' variable is therefore unnecessary and is removed by this patch. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20201007161323.4667-1-berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: introduce icount field for snapshotsPavel Dovgalyuk2020-10-061-0/+3
| | | | | | | | | | | | | | | | This patch introduces the icount field for saving within the snapshot. It is required for navigation between the snapshots in record/replay mode. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Acked-by: Kevin Wolf <kwolf@redhat.com> -- v7 changes: - also fix the test which checks qcow2 snapshot extra data Message-Id: <160174518284.12451.2301137308458777398.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* qcow2: Convert qcow2_alloc_cluster_offset() into qcow2_alloc_host_offset()Alberto Garcia2020-09-151-3/+3
| | | | | | | | | | | | | | | | | qcow2_alloc_cluster_offset() takes an (unaligned) guest offset and returns the (aligned) offset of the corresponding cluster in the qcow2 image. In practice none of the callers need to know where the cluster starts so this patch makes the function calculate and return the final host offset directly. The function is also renamed accordingly. See 388e581615 for a similar change to qcow2_get_cluster_offset(). Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <9bfef50ec9200d752413be4fc2aeb22a28378817.1599833007.git.berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Make qcow2_free_any_clusters() free only one clusterAlberto Garcia2020-09-151-2/+2
| | | | | | | | | | | | | | | | This function takes an L2 entry and a number of clusters to free. Although in principle it can free any type of cluster (using the L2 entry to determine its type) in practice the API is broken because compressed clusters have a variable size and there is no way to free more than one without having the L2 entry of each one of them. The good news all callers are passing nb_clusters=1 so we can simply get rid of that parameter. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <77cea0f4616f921d37e971b3c5b18a2faa24b173.1599573989.git.berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Use macros for the L1, refcount and bitmap table entry sizesAlberto Garcia2020-09-151-0/+6
| | | | | | | | | This patch replaces instances of sizeof(uint64_t) in the qcow2 driver with macros that indicate what those sizes are actually referring to. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200828110828.13833-1-berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bitAlberto Garcia2020-08-251-3/+5
| | | | | | | | | | | | | Now that the implementation of subclusters is complete we can finally add the necessary options to create and read images with this feature, which we call "extended L2 entries". Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <6476caaa73216bd05b7bb2d504a20415e1665176.1594396418.git.berto@igalia.com> [mreitz: %s/5\.1/5.2/; fixed 302's and 303's reference output] Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add prealloc field to QCowL2MetaAlberto Garcia2020-08-251-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This field allows us to indicate that the L2 metadata update does not come from a write request with actual data but from a preallocation request. For traditional images this does not make any difference, but for images with extended L2 entries this means that the clusters are allocated normally in the L2 table but individual subclusters are marked as unallocated. This will allow preallocating images that have a backing file. There is one special case: when we resize an existing image we can also request that the new clusters are preallocated. If the image already had a backing file then we have to hide any possible stale data and zero out the new clusters (see commit 955c7d6687 for more details). In this case the subclusters cannot be left as unallocated so the L2 bitmap must be updated. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <960d4c444a4f5a870e2b47e5da322a73cd9a2f5a.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add subcluster support to qcow2_co_pwrite_zeroes()Alberto Garcia2020-08-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This works now at the subcluster level and pwrite_zeroes_alignment is updated accordingly. qcow2_cluster_zeroize() is turned into qcow2_subcluster_zeroize() with the following changes: - The request can now be subcluster-aligned. - The cluster-aligned body of the request is still zeroized using zero_in_l2_slice() as before. - The subcluster-aligned head and tail of the request are zeroized with the new zero_l2_subclusters() function. There is just one thing to take into account for a possible future improvement: compressed clusters cannot be partially zeroized so zero_l2_subclusters() on the head or the tail can return -ENOTSUP. This makes the caller repeat the *complete* request and write actual zeroes to disk. This is sub-optimal because 1) if the head area was compressed we would still be able to use the fast path for the body and possibly the tail. 2) if the tail area was compressed we are writing zeroes to the head and the body areas, which are already zeroized. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <17e05e2ee7e12f10dcf012da81e83ebe27eb3bef.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add subcluster support to qcow2_get_host_offset()Alberto Garcia2020-08-251-24/+14Star
| | | | | | | | | | | | | | | | The logic of this function remains pretty much the same, except that it uses count_contiguous_subclusters(), which combines the logic of count_contiguous_clusters() / count_contiguous_clusters_unallocated() and checks individual subclusters. qcow2_cluster_to_subcluster_type() is not necessary as a separate function anymore so it's inlined into its caller. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <d2193fd48653a350d80f0eca1c67b1d9053fb2f3.1594396418.git.berto@igalia.com> [mreitz: Initialize expected_type to anything] Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_*Alberto Garcia2020-08-251-1/+1
| | | | | | | | | | | | | | | | | | In order to support extended L2 entries some functions of the qcow2 driver need to start dealing with subclusters instead of clusters. qcow2_get_host_offset() is modified to return the subcluster type instead of the cluster type, and all callers are updated to replace all values of QCow2ClusterType with their QCow2SubclusterType equivalents. This patch only changes the data types, there are no semantic changes. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <f6c29737c295f32cbee74c903c30b01820363b34.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add cluster type parameter to qcow2_get_host_offset()Alberto Garcia2020-08-251-1/+2
| | | | | | | | | | | | | | | | | | | This function returns an integer that can be either an error code or a cluster type (a value from the QCow2ClusterType enum). We are going to start using subcluster types instead of cluster types in some functions so it's better to use the exact data types instead of integers for clarity and in order to detect errors more easily. This patch makes qcow2_get_host_offset() return 0 on success and puts the returned cluster type in a separate parameter. There are no semantic changes. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <396b6eab1859a271551dcd7dcba77f8934aa3c3f.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add qcow2_cluster_is_allocated()Alberto Garcia2020-08-251-0/+6
| | | | | | | | | | | This helper function tells us if a cluster is allocated (that is, there is an associated host offset for it). Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <6d8771c5c79cbdc6c519875a5078e1cc85856d63.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type()Alberto Garcia2020-08-251-1/+125
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds QCow2SubclusterType, which is the subcluster-level version of QCow2ClusterType. All QCOW2_SUBCLUSTER_* values have the the same meaning as their QCOW2_CLUSTER_* equivalents (when they exist). See below for details and caveats. In images without extended L2 entries clusters are treated as having exactly one subcluster so it is possible to replace one data type with the other while keeping the exact same semantics. With extended L2 entries there are new possible values, and every subcluster in the same cluster can obviously have a different QCow2SubclusterType so functions need to be adapted to work on the subcluster level. There are several things that have to be taken into account: a) QCOW2_SUBCLUSTER_COMPRESSED means that the whole cluster is compressed. We do not support compression at the subcluster level. b) There are two different values for unallocated subclusters: QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN which means that the whole cluster is unallocated, and QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC which means that the cluster is allocated but the subcluster is not. The latter can only happen in images with extended L2 entries. c) QCOW2_SUBCLUSTER_INVALID is used to detect the cases where an L2 entry has a value that violates the specification. The caller is responsible for handling these situations. To prevent compatibility problems with images that have invalid values but are currently being read by QEMU without causing side effects, QCOW2_SUBCLUSTER_INVALID is only returned for images with extended L2 entries. qcow2_cluster_to_subcluster_type() is added as a separate function from qcow2_get_subcluster_type(), but this is only temporary and both will be merged in a subsequent patch. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <26ef38e270f25851c98b51278852b4c4a7f97e69.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap()Alberto Garcia2020-08-251-0/+21
| | | | | | | | | | | | | | | | | | | | Extended L2 entries are 128-bit wide: 64 bits for the entry itself and 64 bits for the subcluster allocation bitmap. In order to support them correctly get/set_l2_entry() need to be updated so they take the entry width into account in order to calculate the correct offset. This patch also adds the get/set_l2_bitmap() functions that are used to access the bitmaps. For convenience we allow calling get_l2_bitmap() on images without subclusters. In this case the returned value is always 0 and has no meaning. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <6ee0f81ae3329c991de125618b3675e1e46acdbb.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add l2_entry_size()Alberto Garcia2020-08-251-0/+9
| | | | | | | | | | | | | | qcow2 images with subclusters have 128-bit L2 entries. The first 64 bits contain the same information as traditional images and the last 64 bits form a bitmap with the status of each individual subcluster. Because of that we cannot assume that L2 entries are sizeof(uint64_t) anymore. This function returns the proper value for the image. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <d34d578bd0380e739e2dde3e8dd6187d3d249fa9.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add offset_into_subcluster() and size_to_subclusters()Alberto Garcia2020-08-251-0/+10
| | | | | | | | | | | Like offset_into_cluster() and size_to_clusters(), but for subclusters. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <3cc2390dcdef3d234d47c741b708bd8734490862.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add offset_to_sc_index()Alberto Garcia2020-08-251-0/+5
| | | | | | | | | | | | For a given offset, return the subcluster number within its cluster (i.e. with 32 subclusters per cluster it returns a number between 0 and 31). Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <56e3e4ac0d827c6a2f5f259106c5ddb7c4ca2653.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add subcluster-related fields to BDRVQcow2StateAlberto Garcia2020-08-251-0/+5
| | | | | | | | | | | | | | | | | This patch adds the following new fields to BDRVQcow2State: - subclusters_per_cluster: Number of subclusters in a cluster - subcluster_size: The size of each subcluster, in bytes - subcluster_bits: No. of bits so 1 << subcluster_bits = subcluster_size Images without subclusters are treated as if they had exactly one subcluster per cluster (i.e. subcluster_size = cluster_size). Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <55bfeac86b092fa2c9d182a95cbeb479ff7eca4f.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add dummy has_subclusters() functionAlberto Garcia2020-08-251-0/+6
| | | | | | | | | | | | | | | | | This function will be used by the qcow2 code to check if an image has subclusters or not. At the moment this simply returns false. Once all patches needed for subcluster support are ready then QEMU will be able to create and read images with subclusters and this function will return the actual value. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <905526221083581a1b7057bca1585487661c5c13.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add get_l2_entry() and set_l2_entry()Alberto Garcia2020-08-251-0/+12
| | | | | | | | | | | | | | | | | The size of an L2 entry is 64 bits, but if we want to have subclusters we need extended L2 entries. This means that we have to access L2 tables and slices differently depending on whether an image has extended L2 entries or not. This patch replaces all l2_slice[] accesses with calls to get_l2_entry() and set_l2_entry(). Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <9586363531fec125ba1386e561762d3e4224e9fc.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset()Alberto Garcia2020-08-251-2/+2
| | | | | | | | | | | | | | | | | | | | qcow2_get_cluster_offset() takes an (unaligned) guest offset and returns the (aligned) offset of the corresponding cluster in the qcow2 image. In practice none of the callers need to know where the cluster starts so this patch makes the function calculate and return the final host offset directly. The function is also renamed accordingly. There is a pre-existing exception with compressed clusters: in this case the function returns the complete cluster descriptor (containing the offset and size of the compressed data). This does not change with this patch but it is now documented. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <ffae6cdc5ca8950e8280ac0f696dcc376cb07095.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Expose bitmaps' size during measureEric Blake2020-05-281-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* block: Make it easier to learn which BDS support bitmapsEric Blake2020-05-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* qcow2: introduce compression type featureDenis Plotnikov2020-05-131-1/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch adds some preparation parts for incompatible compression type feature to qcow2 allowing the use different compression methods for image clusters (de)compressing. It is implied that the compression type is set on the image creation and can be changed only later by image conversion, thus compression type defines the only compression algorithm used for the image, and thus, for all image clusters. The goal of the feature is to add support of other compression methods to qcow2. For example, ZSTD which is more effective on compression than ZLIB. The default compression is ZLIB. Images created with ZLIB compression type are backward compatible with older qemu versions. Adding of the compression type breaks a number of tests because now the compression type is reported on image creation and there are some changes in the qcow2 header in size and offsets. The tests are fixed in the following ways: * filter out compression_type for many tests * fix header size, feature table size and backing file offset affected tests: 031, 036, 061, 080 header_size +=8: 1 byte compression type 7 bytes padding feature_table += 48: incompatible feature compression type backing_file_offset += 56 (8 + 48 -> header_change + feature_table_change) * add "compression type" for test output matching when it isn't filtered affected tests: 049, 060, 061, 065, 082, 085, 144, 182, 185, 198, 206, 242, 255, 274, 280 Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> QAPI part: Acked-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20200507082521.29210-2-dplotnikov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Remove unused fields from BDRVQcow2StateKevin Wolf2020-03-271-3/+0Star
| | | | | | | | | | | | | These fields were already removed in commit c3c10f72, but then commit b58deb34 revived them probably due to bad merge conflict resolution. They are still unused, so remove them again. Fixes: b58deb344ddff3b9d8b265bf73a65274767ee5f4 Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200326170757.12344-1-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: Fix QCOW2_COMPRESSED_SECTOR_MASKMax Reitz2019-11-071-1/+1
| | | | | | | | | | | | Masks for L2 table entries should have 64 bit. Fixes: b6c246942b14d3e0dec46a6c5868ed84e7dbea19 Buglink: https://bugs.launchpad.net/qemu/+bug/1850000 Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191028161841.1198-2-mreitz@redhat.com Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add qcow2_check_fix_snapshot_table()Max Reitz2019-10-281-0/+3
| | | | | | | | | | | | | | | | | | | qcow2_check_read_snapshot_table() can perform consistency checks, but it cannot fix everything. Specifically, it cannot allocate new clusters, because that should wait until the refcount structures are known to be consistent (i.e., after qcow2_check_refcounts()). Thus, it cannot call qcow2_write_snapshots(). Do that in qcow2_check_fix_snapshot_table(), which is called after qcow2_check_refcounts(). Currently, there is nothing that would set result->corruptions, so this is a no-op. A follow-up patch will change that. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-10-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Separate qcow2_check_read_snapshot_table()Max Reitz2019-10-281-0/+4
| | | | | | | | | | | | | | | Reading the snapshot table can fail. That is a problem when we want to repair the image. Therefore, stop reading the snapshot table in qcow2_do_open() in check mode. Instead, add a new function qcow2_check_read_snapshot_table() that reads the snapshot table at a later point. In the future, we want to handle errors here and fix them. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-9-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Make qcow2_write_snapshots() publicMax Reitz2019-10-281-0/+1
| | | | | | | | | | Updating the snapshot list will be useful when upgrading a v2 image to v3, so we will need to call this function in qcow2.c. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-6-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Keep unknown extra snapshot dataMax Reitz2019-10-281-0/+7
| | | | | | | | | | | | | | | The qcow2 specification says to ignore unknown extra data fields in snapshot table entries. Currently, we discard it whenever we update the image, which is a bit different from "ignore". This patch makes the qcow2 driver keep all unknown extra data fields when updating an image's snapshot table. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-5-mreitz@redhat.com [mreitz: Adjusted comments as proposed by Eric] Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add Error ** to qcow2_read_snapshots()Max Reitz2019-10-281-1/+1
| | | | | | | Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191011152814.14791-4-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/qcow2-bitmap: do not remove bitmaps on reopen-roVladimir Sementsov-Ogievskiy2019-10-171-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* block/qcow2-bitmap: drop qcow2_reopen_bitmaps_rw_hint()Vladimir Sementsov-Ogievskiy2019-10-171-2/+0Star
| | | | | | | | | 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>
* block/qcow2: proper locking on bitmap add/remove pathsVladimir Sementsov-Ogievskiy2019-10-171-5/+6
| | | | | | | | | | | | | | | | | | 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>
* block/dirty-bitmap: return int from bdrv_remove_persistent_dirty_bitmapVladimir Sementsov-Ogievskiy2019-10-171-3/+2Star
| | | | | | | | | 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>
* block/qcow2: introduce parallel subrequest handling in read and writeVladimir Sementsov-Ogievskiy2019-10-101-0/+3
| | | | | | | | It improves performance for fragmented qcow2 images. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190916175324.18478-6-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/qcow2: refactor encryption codeMaxim Levitsky2019-09-161-4/+4
| | | | | | | | | | | | | | | | | | | * Change the qcow2_co_{encrypt|decrypt} to just receive full host and guest offsets and use this function directly instead of calling do_perform_cow_encrypt (which is removed by that patch). * Adjust qcow2_co_encdec to take full host and guest offsets as well. * Document the qcow2_co_{encrypt|decrypt} arguments to prevent the bug fixed in former commit from hopefully happening again. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-id: 20190915203655.21638-3-mlevitsk@redhat.com Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> [mreitz: Let perform_cow() return the error value returned by qcow2_co_encrypt(), as proposed by Vladimir] Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/qcow2: implement .bdrv_co_pwritev(_compressed)_partVladimir Sementsov-Ogievskiy2019-08-271-0/+1
| | | | | | | | | | Implement and use new interface to get rid of hd_qiov. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-13-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-13-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: avoid recursive block_status call if possibleVladimir Sementsov-Ogievskiy2019-06-041-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | drv_co_block_status digs bs->file for additional, more accurate search for hole inside region, reported as DATA by bs since 5daa74a6ebc. This accuracy is not free: assume we have qcow2 disk. Actually, qcow2 knows, where are holes and where is data. But every block_status request calls lseek additionally. Assume a big disk, full of data, in any iterative copying block job (or img convert) we'll call lseek(HOLE) on every iteration, and each of these lseeks will have to iterate through all metadata up to the end of file. It's obviously ineffective behavior. And for many scenarios we don't need this lseek at all. However, lseek is needed when we have metadata-preallocated image. So, let's detect metadata-preallocation case and don't dig qcow2's protocol file in other cases. The idea is to compare allocation size in POV of filesystem with allocations size in POV of Qcow2 (by refcounts). If allocation in fs is significantly lower, consider it as metadata-preallocation case. 102 iotest changed, as our detector can't detect shrinked file as metadata-preallocation, which don't seem to be wrong, as with metadata preallocation we always have valid file length. Two other iotests have a slight change in their QMP output sequence: Active 'block-commit' returns earlier because the job coroutine yields earlier on a blocking operation. This operation is loading the refcount blocks in qcow2_detect_metadata_preallocation(). Suggested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: skip writing zero buffers to empty COW areasAnton Nefedov2019-05-281-0/+6
| | | | | | | | | | | | | | | | | If COW areas of the newly allocated clusters are zeroes on the backing image, efficient bdrv_write_zeroes(flags=BDRV_REQ_NO_FALLBACK) can be used on the whole cluster instead of writing explicit zero buffers later in perform_cow(). iotest 060: write to the discarded cluster does not trigger COW anymore. Use a backing image instead. Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Message-id: 20190516142749.81019-2-anton.nefedov@virtuozzo.com Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: do encryption in threadsVladimir Sementsov-Ogievskiy2019-05-281-0/+8
| | | | | | | | | | | Do encryption/decryption in threads, like it is already done for compression. This improves asynchronous encrypted io. 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: 20190506142741.41731-9-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2-threads: split out generic pathVladimir Sementsov-Ogievskiy2019-05-281-2/+2
| | | | | | | | | | | Move generic part out of qcow2_co_do_compress, to reuse it for encryption and rename things that would be shared with encryption path. 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: 20190506142741.41731-6-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: add separate file for threaded data processing functionsVladimir Sementsov-Ogievskiy2019-05-281-0/+7
| | | | | | | | | | | Move compression-on-threads to separate file. Encryption will be in it too. 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: 20190506142741.41731-3-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2.h: add missing includeVladimir Sementsov-Ogievskiy2019-05-281-0/+1
| | | | | | | | | | | | 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>
* qcow2: Define and use QCOW2_COMPRESSED_SECTOR_SIZEAlberto Garcia2019-05-201-0/+4
| | | | | | | | | | | | When an L2 table entry points to a compressed cluster the space used by the data is specified in 512-byte sectors. This size is independent from BDRV_SECTOR_SIZE and is specific to the qcow2 file format. The QCOW2_COMPRESSED_SECTOR_SIZE constant defined in this patch makes this explicit. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: Remove BDRVQcow2State.cluster_sectorsAlberto Garcia2019-05-101-1/+0Star
| | | | | | | | | The last user of this field disappeared when we replace the sector-based bdrv_write() with the byte-based bdrv_pwrite(). Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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