summaryrefslogtreecommitdiffstats
path: root/block/qcow2.c
Commit message (Collapse)AuthorAgeFilesLines
* qcow2: switch to *_co_* functionsAlberto Faria2022-10-271-12/+12
| | | | | | | | Signed-off-by: Alberto Faria <afaria@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221013123711.620631-20-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: add coroutine_fn annotation for indirect-called functionsAlberto Faria2022-10-271-4/+4
| | | | | | | | Signed-off-by: Alberto Faria <afaria@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221013123711.620631-10-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: introduce bdrv_open_file_child() helperVladimir Sementsov-Ogievskiy2022-10-271-4/+4
| | | | | | | | | | | | | | | | | | | | | | | Almost all drivers call bdrv_open_child() similarly. Let's create a helper for this. The only not updated drivers that call bdrv_open_child() to set bs->file are raw-format and snapshot-access: raw-format sometimes want to have filtered child but don't set drv->is_filter to true. snapshot-access wants only DATA | PRIMARY Possibly we should implement drv->is_filter_func() handler, to consider raw-format as filter when it works as filter.. But it's another story. Note also, that we decrease assignments to bs->file in code: it helps us restrict modifying this field in further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-3-vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: add missing coroutine_fn annotationsPaolo Bonzini2022-10-071-2/+3
| | | | | | | | | | | | | Callers of coroutine_fn must be coroutine_fn themselves, or the call must be within "if (qemu_in_coroutine())". Apply coroutine_fn to functions where this holds. Reviewed-by: Alberto Faria <afaria@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20220922084924.201610-15-pbonzini@redhat.com> [kwolf: Fixed up coding style] Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block/qcow2: Keep auto_backing_file if possibleHanna Reitz2022-09-301-5/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | qcow2_do_open() is used by qcow2_co_invalidate_cache(), i.e. may be run on an image that has been opened before. When reading the backing file string from the image header, compare it against the existing bs->backing_file, and update bs->auto_backing_file only if they differ. auto_backing_file should ideally contain the filename the backing BDS will actually have after opening, i.e. a post-bdrv_refresh_filename() version of what is in the image header. So for example, if the image header reports the following backing file string: json:{"driver": "qcow2", "file": { "driver": "file", "filename": "/tmp/backing.qcow2" }} Then auto_backing_file should contain simply "/tmp/backing.qcow2". Because bdrv_refresh_filename() only works on existing BDSs, though, the way how we get this auto_backing_file value is to have the format driver set it to whatever is in the image header, and when the backing BDS is opened based on that, we update it with the filename the backing BDS actually got. However, qcow2's qcow2_co_invalidate_cache() implementation breaks this because it just resets auto_backing_file to whatever is in the image file without opening a BDS based on it, so we never get auto_backing_file back to the "refreshed" version, and in the example above, it would stay "json:{...}". Then, bs->backing->bs->filename will differ from bs->auto_backing_file, making bdrv_backing_overridden(bs) return true, which will lead bdrv_refresh_filename(bs) to generate a json:{} filename for bs, even though that may not have been necessary. This is reported in the issue linked below. Therefore, skip updating auto_backing_file if nothing has changed in the image header since we last read it. Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1117 Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220803144446.20723-2-hreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: fix memory leak in qcow2_read_extensionslu zhipeng2022-09-301-0/+1
| | | | | | | | | Free feature_table if it is failed in bdrv_pread. Signed-off-by: lu zhipeng <luzhipeng@cestc.cn> Message-Id: <20220921144515.1166-1-luzhipeng@cestc.cn> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Change blk_{pread,pwrite}() param orderAlberto Faria2022-07-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Swap 'buf' and 'bytes' around for consistency with blk_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression blk, offset, buf, bytes, flags; @@ - blk_pread(blk, offset, buf, bytes, flags) + blk_pread(blk, offset, bytes, buf, flags) @@ expression blk, offset, buf, bytes, flags; @@ - blk_pwrite(blk, offset, buf, bytes, flags) + blk_pwrite(blk, offset, bytes, buf, flags) It had no effect on hw/block/nand.c, presumably due to the #if, so that file was updated manually. Overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-4-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* block/qcow2: Use bdrv_pwrite_sync() in qcow2_mark_dirty()Alberto Faria2022-07-121-6/+3Star
| | | | | | | | | | | | Use bdrv_pwrite_sync() instead of calling bdrv_pwrite() and bdrv_flush() separately. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220609152744.3891847-11-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* block: Use bdrv_co_pwrite_sync() when caller is coroutine_fnAlberto Faria2022-07-121-2/+2
| | | | | | | | | | | | Convert uses of bdrv_pwrite_sync() into bdrv_co_pwrite_sync() when the callers are already coroutine_fn. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <v.sementsov-og@mail.ru> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220609152744.3891847-10-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* crypto: Make block callbacks return 0 on successAlberto Faria2022-07-121-11/+11
| | | | | | | | | | | | | They currently return the value of their headerlen/buflen parameter on success. Returning 0 instead makes it clear that short reads/writes are not possible. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220609152744.3891847-5-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* block: Make bdrv_{pread,pwrite}() return 0 on successAlberto Faria2022-07-121-2/+2
| | | | | | | | | | | | | | | | | | They currently return the value of their 'bytes' parameter on success. Make them return 0 instead, for consistency with other I/O functions and in preparation to implement them using generated_co_wrapper. This also makes it clear that short reads/writes are not possible. The few callers that rely on the previous behavior are adjusted accordingly by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220609152744.3891847-4-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* block: Change bdrv_{pread,pwrite,pwrite_sync}() param orderAlberto Faria2022-07-121-23/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Swap 'buf' and 'bytes' around for consistency with bdrv_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pread(child, offset, buf, bytes, flags) + bdrv_pread(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite(child, offset, buf, bytes, flags) + bdrv_pwrite(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite_sync(child, offset, buf, bytes, flags) + bdrv_pwrite_sync(child, offset, bytes, buf, flags) Resulting overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220609152744.3891847-3-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* block: Add a 'flags' param to bdrv_{pread,pwrite,pwrite_sync}()Alberto Faria2022-07-121-22/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | For consistency with other I/O functions, and in preparation to implement them using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression child, offset, buf, bytes; @@ - bdrv_pread(child, offset, buf, bytes) + bdrv_pread(child, offset, buf, bytes, 0) @@ expression child, offset, buf, bytes; @@ - bdrv_pwrite(child, offset, buf, bytes) + bdrv_pwrite(child, offset, buf, bytes, 0) @@ expression child, offset, buf, bytes; @@ - bdrv_pwrite_sync(child, offset, buf, bytes) + bdrv_pwrite_sync(child, offset, buf, bytes, 0) Resulting overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220609152744.3891847-2-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* qcow2: Do not reopen data_file in invalidate_cacheHanna Reitz2022-05-041-42/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | qcow2_co_invalidate_cache() closes and opens the qcow2 file, by calling qcow2_close() and qcow2_do_open(). These two functions must thus be usable from both a global-state and an I/O context. As they are, they are not safe to call in an I/O context, because they use bdrv_unref_child() and bdrv_open_child() to close/open the data_file child, respectively, both of which are global-state functions. When used from qcow2_co_invalidate_cache(), we do not need to close/open the data_file child, though (we do not do this for bs->file or bs->backing either), and so we should skip it in the qcow2_co_invalidate_cache() path. To do so, add a parameter to qcow2_do_open() and qcow2_close() to make them skip handling s->data_file, and have qcow2_co_invalidate_cache() exempt it from the memset() on the BDRVQcow2State. (Note that the QED driver similarly closes/opens the QED image by invoking bdrv_qed_close()+bdrv_qed_do_open(), but both functions seem safe to use in an I/O context.) Fixes: https://gitlab.com/qemu-project/qemu/-/issues/945 Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220427114057.36651-3-hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* osdep: Move memalign-related functions to their own headerPeter Maydell2022-03-071-0/+1
| | | | | | | | | | | Move the various memalign-related functions out of osdep.h and into their own header, which we include only where they are used. While we're doing this, add some brief documentation comments. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 20220226180723.1706285-10-peter.maydell@linaro.org
* qcow2: simple case support for downgrading of qcow2 images with zstdVladimir Sementsov-Ogievskiy2022-02-011-2/+56
| | | | | | | | | | | | | | | | If image doesn't have any compressed cluster we can easily switch to zlib compression, which may allow to downgrade the image. That's mostly needed to support IMGOPTS='compression_type=zstd' in some iotests which do qcow2 downgrade. While being here also fix checkpatch complain against '#' in printf formatting. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20211223160144.1097696-13-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* block: use int64_t instead of int in driver discard handlersVladimir Sementsov-Ogievskiy2021-09-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver discard handlers bytes parameter to int64_t. The only caller of all updated function is bdrv_co_pdiscard in block/io.c. It is already prepared to work with 64bit requests, but pass at most max(bs->bl.max_pdiscard, INT_MAX) to the driver. Let's look at all updated functions: blkdebug: all calculations are still OK, thanks to bdrv_check_qiov_request(). both rule_check and bdrv_co_pdiscard are 64bit blklogwrites: pass to blk_loc_writes_co_log which is 64bit blkreplay, copy-on-read, filter-compress: pass to bdrv_co_pdiscard, OK copy-before-write: pass to bdrv_co_pdiscard which is 64bit and to cbw_do_copy_before_write which is 64bit file-posix: one handler calls raw_account_discard() is 64bit and both handlers calls raw_do_pdiscard(). Update raw_do_pdiscard, which pass to RawPosixAIOData::aio_nbytes, which is 64bit (and calls raw_account_discard()) gluster: somehow, third argument of glfs_discard_async is size_t. Let's set max_pdiscard accordingly. iscsi: iscsi_allocmap_set_invalid is 64bit, !is_byte_request_lun_aligned is 64bit. list.num is uint32_t. Let's clarify max_pdiscard and pdiscard_alignment. mirror_top: pass to bdrv_mirror_top_do_write() which is 64bit nbd: protocol limitation. max_pdiscard is alredy set strict enough, keep it as is for now. nvme: buf.nlb is uint32_t and we do shift. So, add corresponding limits to nvme_refresh_limits(). preallocate: pass to bdrv_co_pdiscard() which is 64bit. rbd: pass to qemu_rbd_start_co() which is 64bit. qcow2: calculations are still OK, thanks to bdrv_check_qiov_request(), qcow2_cluster_discard() is 64bit. raw-format: raw_adjust_offset() is 64bit, bdrv_co_pdiscard too. throttle: pass to bdrv_co_pdiscard() which is 64bit and to throttle_group_co_io_limits_intercept() which is 64bit as well. test-block-iothread: bytes argument is unused Great! Now all drivers are prepared to handle 64bit discard requests, or else have explicit max_pdiscard limits. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-11-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block: use int64_t instead of int in driver write_zeroes handlersVladimir Sementsov-Ogievskiy2021-09-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver write_zeroes handlers bytes parameter to int64_t. The only caller of all updated function is bdrv_co_do_pwrite_zeroes(). bdrv_co_do_pwrite_zeroes() itself is of course OK with widening of callee parameter type. Also, bdrv_co_do_pwrite_zeroes()'s max_write_zeroes is limited to INT_MAX. So, updated functions all are safe, they will not get "bytes" larger than before. Still, let's look through all updated functions, and add assertions to the ones which are actually unprepared to values larger than INT_MAX. For these drivers also set explicit max_pwrite_zeroes limit. Let's go: blkdebug: calculations can't overflow, thanks to bdrv_check_qiov_request() in generic layer. rule_check() and bdrv_co_pwrite_zeroes() both have 64bit argument. blklogwrites: pass to blk_log_writes_co_log() with 64bit argument. blkreplay, copy-on-read, filter-compress: pass to bdrv_co_pwrite_zeroes() which is OK copy-before-write: Calls cbw_do_copy_before_write() and bdrv_co_pwrite_zeroes, both have 64bit argument. file-posix: both handler calls raw_do_pwrite_zeroes, which is updated. In raw_do_pwrite_zeroes() calculations are OK due to bdrv_check_qiov_request(), bytes go to RawPosixAIOData::aio_nbytes which is uint64_t. Check also where that uint64_t gets handed: handle_aiocb_write_zeroes_block() passes a uint64_t[2] to ioctl(BLKZEROOUT), handle_aiocb_write_zeroes() calls do_fallocate() which takes off_t (and we compile to always have 64-bit off_t), as does handle_aiocb_write_zeroes_unmap. All look safe. gluster: bytes go to GlusterAIOCB::size which is int64_t and to glfs_zerofill_async works with off_t. iscsi: Aha, here we deal with iscsi_writesame16_task() that has uint32_t num_blocks argument and iscsi_writesame16_task() has uint16_t argument. Make comments, add assertions and clarify max_pwrite_zeroes calculation. iscsi_allocmap_() functions already has int64_t argument is_byte_request_lun_aligned is simple to update, do it. mirror_top: pass to bdrv_mirror_top_do_write which has uint64_t argument nbd: Aha, here we have protocol limitation, and NBDRequest::len is uint32_t. max_pwrite_zeroes is cleanly set to 32bit value, so we are OK for now. nvme: Again, protocol limitation. And no inherent limit for write-zeroes at all. But from code that calculates cdw12 it's obvious that we do have limit and alignment. Let's clarify it. Also, obviously the code is not prepared to handle bytes=0. Let's handle this case too. trace events already 64bit preallocate: pass to handle_write() and bdrv_co_pwrite_zeroes(), both 64bit. rbd: pass to qemu_rbd_start_co() which is 64bit. qcow2: offset + bytes and alignment still works good (thanks to bdrv_check_qiov_request()), so tail calculation is OK qcow2_subcluster_zeroize() has 64bit argument, should be OK trace events updated qed: qed_co_request wants int nb_sectors. Also in code we have size_t used for request length which may be 32bit. So, let's just keep INT_MAX as a limit (aligning it down to pwrite_zeroes_alignment) and don't care. raw-format: Is OK. raw_adjust_offset and bdrv_co_pwrite_zeroes are both 64bit. throttle: Both throttle_group_co_io_limits_intercept() and bdrv_co_pwrite_zeroes() are 64bit. vmdk: pass to vmdk_pwritev which is 64bit quorum: pass to quorum_co_pwritev() which is 64bit Hooray! At this point all block drivers are prepared to support 64bit write-zero requests, or have explicitly set max_pwrite_zeroes. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-8-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: use <= rather than < in assertions relying on max_pwrite_zeroes] Signed-off-by: Eric Blake <eblake@redhat.com>
* block: use int64_t instead of uint64_t in copy_range driver handlersVladimir Sementsov-Ogievskiy2021-09-291-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver copy_range handlers parameters which are already 64bit to signed type. Now let's consider all callers. Simple git grep '\->bdrv_co_copy_range' shows the only caller: bdrv_co_copy_range_internal(), which does bdrv_check_request32(), so everything is OK. Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_co_copy_range_\(from\|to\)\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done shows no more callers. So, we are done. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20210903102807.27127-6-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block: use int64_t instead of uint64_t in driver write handlersVladimir Sementsov-Ogievskiy2021-09-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver write handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_pwritev\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_pwritev() and bdrv_driver_pwritev_compressed() in block/io.c, both pass int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_save_vmstate() does bdrv_check_qiov_request(). Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_pwritev\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done shows several callers: qcow2: qcow2_co_truncate() write at most up to @offset, which is checked in generic qcow2_co_truncate() by bdrv_check_request(). qcow2_co_pwritev_compressed_task() pass the request (or part of the request) that already went through normal write path, so it should be OK qcow: qcow_co_pwritev_compressed() pass int64_t, it's updated by this patch quorum: quorum_co_pwrite_zeroes() pass int64_t and int - OK throttle: throttle_co_pwritev_compressed() pass int64_t, it's updated by this patch vmdk: vmdk_co_pwritev_compressed() pass int64_t, it's updated by this patch Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-5-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block: use int64_t instead of uint64_t in driver read handlersVladimir Sementsov-Ogievskiy2021-09-291-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver read handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_preadv() in block/io.c, passes int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_load_vmstate() does bdrv_check_qiov_request(). do_perform_cow_read() has uint64_t argument. And a lot of things in qcow2 driver are uint64_t, so converting it is big job. But we must not work with requests that don't satisfy bdrv_check_qiov_request(), so let's just assert it here. Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done The only one such caller: QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); ... ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); in tests/unit/test-bdrv-drain.c, and it's OK obviously. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: fix typos] Signed-off-by: Eric Blake <eblake@redhat.com>
* qcow2: check request on vmstate save/load pathVladimir Sementsov-Ogievskiy2021-09-291-6/+37
| | | | | | | | | | | We modify the request by adding an offset to vmstate. Let's check the modified request. It will help us to safely move .bdrv_co_preadv_part and .bdrv_co_pwritev_part to int64_t type of offset and bytes. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20210903102807.27127-3-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* qcow2: introduce qcow2_parse_compressed_l2_entry() helperVladimir Sementsov-Ogievskiy2021-09-151-7/+2Star
| | | | | | | | | | | | | | | Add helper to parse compressed l2_entry and use it everywhere instead of open-coding. Note, that in most places we move to precise coffset/csize instead of sector-aligned. Still it should work good enough for updating refcounts. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20210914122454.141075-4-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* qcow2: compressed read: simplify cluster descriptor passingVladimir Sementsov-Ogievskiy2021-09-151-5/+7
| | | | | | | | | | | | | | | Let's pass the whole L2 entry and not bother with L2E_COMPRESSED_OFFSET_SIZE_MASK. It also helps further refactoring that adds generic qcow2_parse_compressed_l2_entry() helper. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20210914122454.141075-3-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
* qcow2: Fix dangling pointer after reopen for 'file'Kevin Wolf2021-07-091-0/+29
| | | | | | | | | | | | | | | | Without an external data file, s->data_file is a second pointer with the same value as bs->file. When changing bs->file to a different BdrvChild and freeing the old BdrvChild, s->data_file must also be updated, otherwise it points to freed memory and causes crashes. This problem was caught by iotests case 245. Fixes: df2b7086f169239ebad5d150efa29c9bb6d4f820 Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210708114709.206487-2-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: Prohibit backing file changes in 'qemu-img amend'Eric Blake2021-07-091-9/+4Star
| | | | | | | | | | | | | This was deprecated back in bc5ee6da7 (qcow2: Deprecate use of qemu-img amend to change backing file), and no one in the meantime has given any reasons why it should be supported. Time to make change attempts a hard error (but for convenience, specifying the _same_ backing chain is not forbidden). Update a couple of iotests to match. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210503213600.569128-2-eblake@redhat.com> Reviewed-by: Connor Kuehl <ckuehl@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: consistently use bdrv_is_read_only()Vladimir Sementsov-Ogievskiy2021-06-021-3/+2Star
| | | | | | | | | | | | | | It's better to use accessor function instead of bs->read_only directly. In some places use bdrv_is_writable() instead of checking both BDRV_O_RDWR set and BDRV_O_INACTIVE not set. In bdrv_open_common() it's a bit strange to add one more variable, but we are going to drop bs->read_only in the next patch, so new ro local variable substitutes it here. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210527154056.70294-2-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: set bdi->is_dirtyVladimir Sementsov-Ogievskiy2021-05-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set bdi->is_dirty, so that qemu-img info could show dirty flag. After this commit the following check will show '"dirty-flag": true': ./build/qemu-img create -f qcow2 -o lazy_refcounts=on x 1M ./build/qemu-io x qemu-io> write 0 1M After "write" command success, kill the qemu-io process: kill -9 <qemu-io pid> ./build/qemu-img info --output=json x This will show '"dirty-flag": true' among other things. (before this commit it shows '"dirty-flag": false') Note, that qcow2's dirty-bit is not a "dirty bit for the image". It only protects qcow2 lazy refcounts feature. So, there are a lot of conditions when qcow2 session may be not closed correctly, but bit is 0. Still, when bit is set, the last session is definitely not finished correctly and it's better to report it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210504160656.462836-1-vsementsov@virtuozzo.com> Tested-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qcow2: Force preallocation with data-file-rawMax Reitz2021-03-301-0/+34
| | | | | | | | | | | | | | | | | | Setting the qcow2 data-file-raw bit means that you can ignore the qcow2 metadata when reading from the external data file. It does not mean that you have to ignore it, though. Therefore, the data read must be the same regardless of whether you interpret the metadata or whether you ignore it, and thus the L1/L2 tables must all be present and give a 1:1 mapping. This patch changes 244's output: First, the qcow2 file is larger right after creation, because of metadata preallocation. Second, the qemu-img map output changes: Everything that was not explicitly discarded or zeroed is now a data area. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210326145509.163455-2-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
* qcow2: use external virtual timersPavel Dovgalyuk2021-03-291-3/+4
| | | | | | | | | | | | | | | Regular virtual timers are used to emulate timings related to vCPU and peripheral states. QCOW2 uses timers to clean the cache. These timers should have external flag. In the opposite case they affect the execution and it can't be recorded and replayed. This patch adds external flag to the timer for qcow2 cache clean. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <161700516327.1141158.8366564693714562536.stgit@pasha-ThinkPad-X280> Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/qcow2: refactor qcow2_update_options_prepare error pathsVladimir Sementsov-Ogievskiy2021-03-081-3/+8
| | | | | | | | | | | Keep setting ret close to setting errp and don't merge different error paths into one. This way it's more obvious that we don't return error without setting errp. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20210202124956.63146-15-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block/qcow2: simplify qcow2_co_invalidate_cache()Vladimir Sementsov-Ogievskiy2021-03-081-9/+4Star
| | | | | | | | | | | | | | | | qcow2_do_open correctly sets errp on each failure path. So, we can simplify code in qcow2_co_invalidate_cache() and drop explicit error propagation. Add ERRP_GUARD() as mandated by the documentation in include/qapi/error.h so that error_prepend() is actually called even if errp is &error_fatal. 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: <20210202124956.63146-13-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block/qcow2: read_cache_sizes: return status valueVladimir Sementsov-Ogievskiy2021-03-081-10/+9Star
| | | | | | | | | | | It's better to return status together with setting errp. It allows to reduce error propagation. 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: <20210202124956.63146-12-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block/qcow2-bitmap: improve qcow2_load_dirty_bitmaps() interfaceVladimir Sementsov-Ogievskiy2021-03-081-4/+2Star
| | | | | | | | | | | | 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-Ogievskiy2021-03-081-7/+3Star
| | | | | | | | | | | | 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: check return value of bdrv_open_child and drop error propagationVladimir Sementsov-Ogievskiy2021-03-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is generated by cocci script: @@ symbol bdrv_open_child, errp, local_err; expression file; @@ file = bdrv_open_child(..., - &local_err + errp ); - if (local_err) + if (!file) { ... - error_propagate(errp, local_err); ... } with command spatch --sp-file x.cocci --macro-file scripts/cocci-macro-file.h \ --in-place --no-show-diff --max-width 80 --use-gitgrep block 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: <20210202124956.63146-4-vsementsov@virtuozzo.com> [eblake: fix qcow2_do_open() to use ERRP_GUARD, necessary as the only caller to pass allow_none=true] Signed-off-by: Eric Blake <eblake@redhat.com>
* block: qcow2: remove the created file on initialization errorMaxim Levitsky2021-02-151-3/+5
| | | | | | | | | | | | | If the qcow initialization fails, we should remove the file if it was already created, to avoid leaving stale files around. We already do this for luks raw images. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20201217170904.946013-4-mlevitsk@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* Remove superfluous timer_del() callsPeter Maydell2021-01-081-1/+0Star
| | | | | | | | | | | | This commit is the result of running the timer-del-timer-free.cocci script on the whole source tree. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20201215154107.3255-4-peter.maydell@linaro.org
* block: Fix some code style problems, "foo* bar" should be "foo *bar"shiliyang2020-11-091-2/+2
| | | | | | | | | | 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 Garcia2020-11-091-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Skip copy-on-write when allocating a zero clusterAlberto Garcia2020-10-271-16/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit c8bb23cbdbe32f5c326365e0a82e1b0e68cdcd8a when a write request results in a new allocation QEMU first tries to see if the rest of the cluster outside the written area contains only zeroes. In that case, instead of doing a normal copy-on-write operation and writing explicit zero buffers to disk, the code zeroes the whole cluster efficiently using pwrite_zeroes() with BDRV_REQ_NO_FALLBACK. This improves performance very significantly but it only happens when we are writing to an area that was completely unallocated before. Zero clusters (QCOW2_CLUSTER_ZERO_*) are treated like normal clusters and are therefore slower to allocate. This happens because the code uses bdrv_is_allocated_above() rather bdrv_block_status_above(). The former is not as accurate for this purpose but it is faster. However in the case of qcow2 the underlying call does already report zero clusters just fine so there is no reason why we cannot use that information. After testing 4KB writes on an image that only contains zero clusters this patch results in almost five times more IOPS. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <6d77cab968c501c44d6e1089b9bc91b04170b49e.1603731354.git.berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block/io: fix bdrv_co_block_status_aboveVladimir Sementsov-Ogievskiy2020-10-231-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bdrv_co_block_status_above has several design problems with handling short backing files: 1. With want_zeros=true, it may return ret with BDRV_BLOCK_ZERO but without BDRV_BLOCK_ALLOCATED flag, when actually short backing file which produces these after-EOF zeros is inside requested backing sequence. 2. With want_zero=false, it may return pnum=0 prior to actual EOF, because of EOF of short backing file. Fix these things, making logic about short backing files clearer. With fixed bdrv_block_status_above we also have to improve is_zero in qcow2 code, otherwise iotest 154 will fail, because with this patch we stop to merge zeros of different types (produced by fully unallocated in the whole backing chain regions vs produced by short backing files). Note also, that this patch leaves for another day the general problem around block-status: misuse of BDRV_BLOCK_ALLOCATED as is-fs-allocated vs go-to-backing. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20200924194003.22080-2-vsementsov@virtuozzo.com [Fix s/comes/come/ as suggested by Eric Blake --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* qcow2: Convert qcow2_alloc_cluster_offset() into qcow2_alloc_host_offset()Alberto Garcia2020-09-151-23/+13Star
| | | | | | | | | | | | | | | | | 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 preallocate_co() resize the image to the correct sizeAlberto Garcia2020-09-151-0/+1
| | | | | | | | | | | | | | | | | | | | This function preallocates metadata structures and then extends the image to its new size, but that new size calculation is wrong because it doesn't take into account that the host_offset variable is always cluster-aligned. This problem can be reproduced with preallocation=metadata when the original size is not cluster-aligned but the new size is. In this case the final image size will be shorter than expected. qemu-img create -f qcow2 img.qcow2 31k qemu-img resize --preallocation=metadata img.qcow2 128k Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <adeb8b059917b141d5f5b3bd2a016262d3052c79.1599833007.git.berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> [mreitz: Mark compat=0.10 unsupported for iotest 125] Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Return the original error code in qcow2_co_pwrite_zeroes()Alberto Garcia2020-09-151-1/+1
| | | | | | | | | | | | | | | | | | | | This function checks the current status of a (sub)cluster in order to see if an unaligned 'write zeroes' request can be done efficiently by simply updating the L2 metadata and without having to write actual zeroes to disk. If the situation does not allow using the fast path then the function returns -ENOTSUP and the caller falls back to writing zeroes. If can happen however that the aforementioned check returns an actual error code so in this case we should pass it to the caller. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200909123739.719-1-berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Handle QCowL2Meta on error in preallocate_co()Alberto Garcia2020-09-151-23/+17Star
| | | | | | | | | | | | | | | | | | | If qcow2_alloc_cluster_offset() or qcow2_alloc_cluster_link_l2() fail then this function simply returns the error code, potentially leaking the QCowL2Meta structure and leaving stale items in s->cluster_allocs. A second problem is that this function calls qcow2_free_any_clusters() on failure but passing a host cluster offset instead of an L2 entry. Luckily for normal uncompressed clusters a raw offset also works like a valid L2 entry so it works just the same, but we should be using qcow2_free_clusters() instead. This patch fixes both problems by using qcow2_handle_l2meta(). Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <cd3a6b9abd43f9c0b60be413d760f0cacc67eb66.1599573989.git.berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Don't check nb_clusters when removing l2meta from the listAlberto Garcia2020-09-151-3/+1Star
| | | | | | | | | | | | | | In the past, when a new cluster was allocated the l2meta structure was a variable in the stack so it was necessary to have a way to tell whether it had been initialized and contained valid data or not. The nb_clusters field was used for this purpose. Since commit f50f88b9fe this is no longer the case, l2meta (nowadays a pointer to a list) is only allocated when needed and nb_clusters is guaranteed to be > 0 so this check is unnecessary. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <ab0b67c29c7ba26e598db35f12aa5ab5982539c1.1599150873.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Use macros for the L1, refcount and bitmap table entry sizesAlberto Garcia2020-09-151-14/+13Star
| | | | | | | | | 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: Allow preallocation and backing files if extended_l2 is setAlberto Garcia2020-08-251-3/+4
| | | | | | | | | | | | | | | | Traditional qcow2 images don't allow preallocation if a backing file is set. This is because once a cluster is allocated there is no way to tell that its data should be read from the backing file. Extended L2 entries have individual allocation bits for each subcluster, and therefore it is perfectly possible to have an allocated cluster with all its subclusters unallocated. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <6d5b0f38e7dc5f2f31d8cab1cb92044e9909aece.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bitAlberto Garcia2020-08-251-6/+60
| | | | | | | | | | | | | 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>
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-12-18 12:51:15 +0100