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2021-12-28blockjob: drop BlockJob.blk fieldVladimir Sementsov-Ogievskiy1-7/+0
It's unused now (except for permission handling)[*]. The only reasonable user of it was block-stream job, recently updated to use own blk. And other block jobs prefer to use own source node related objects. So, the arguments of dropping the field are: - block jobs prefer not to use it - block jobs usually has more then one node to operate on, and better to operate symmetrically (for example has both source and target blk's in specific block-job state structure) *: BlockJob.blk is used to keep some permissions. We simply move permissions to block-job child created in block_job_create() together with blk. In mirror, we just should not care anymore about restoring state of blk. Most probably this code could be dropped long ago, after dropping bs->job pointer. Now it finally goes away together with BlockJob.blk itself. iotest 141 output is updated, as "bdrv_has_blk(bs)" check in qmp_blockdev_del() doesn't fail (we don't have blk now). Still, new error message looks even better. In iotest 283 we need to add a job id, otherwise "Invalid job ID" happens now earlier than permission check (as permissions moved from blk to block-job node). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Nikita Lapshin <nikita.lapshin@virtuozzo.com>
2021-12-28block/stream: add own blkVladimir Sementsov-Ogievskiy1-6/+18
block-stream is the only block-job, that reasonably use BlockJob.blk. We are going to drop BlockJob.blk soon. So, let block-stream have own blk. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Nikita Lapshin <nikita.lapshin@virtuozzo.com>
2021-12-21nbd: allow reconnect on open, with corresponding new optionsVladimir Sementsov-Ogievskiy1-1/+44
It is useful when start of vm and start of nbd server are not simple to sync. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2021-12-09block/nvme: fix infinite loop in nvme_free_req_queue_cb()Stefan Hajnoczi1-2/+3
When the request free list is exhausted the coroutine waits on q->free_req_queue for the next free request. Whenever a request is completed a BH is scheduled to invoke nvme_free_req_queue_cb() and wake up waiting coroutines. 1. nvme_get_free_req() waits for a free request: while (q->free_req_head == -1) { ... trace_nvme_free_req_queue_wait(q->s, q->index); qemu_co_queue_wait(&q->free_req_queue, &q->lock); ... } 2. nvme_free_req_queue_cb() wakes up the coroutine: while (qemu_co_enter_next(&q->free_req_queue, &q->lock)) { ^--- infinite loop when free_req_head == -1 } nvme_free_req_queue_cb() and the coroutine form an infinite loop when q->free_req_head == -1. Fix this by checking q->free_req_head in nvme_free_req_queue_cb(). If the free request list is exhausted, don't wake waiting coroutines. Eventually an in-flight request will complete and the BH will be scheduled again, guaranteeing forward progress. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20211208152246.244585-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-11-23block/vvfat.c fix leak when failure occursDaniella Lee1-4/+12
Function vvfat_open called function enable_write_target and init_directories, and these functions malloc new memory for BDRVVVFATState::qcow_filename, BDRVVVFATState::used_clusters, and BDRVVVFATState::cluster_buff. When the specified folder does not exist ,it may contains memory leak. After init_directories function is executed, the vvfat_open return -EIO, and bdrv_open_driver goto label open_failed, the program use g_free(bs->opaque) to release BDRVVVFATState struct without members mentioned. command line: qemu-system-x86_64 -hdb <vdisk qcow file> -usb -device usb-storage,drive=fat16 -drive file=fat:rw:fat-type=16:"<path of a host folder does not exist>", id=fat16,format=raw,if=none enable_write_target called: (gdb) bt at ../block/vvfat.c:3114 flags=155650, errp=0x7fffffffd780) at ../block/vvfat.c:1236 node_name=0x0, options=0x555556fa45d0, open_flags=155650, errp=0x7fffffffd890) at ../block.c:1558 errp=0x7fffffffd890) at ../block.c:1852 reference=0x0, options=0x555556fa45d0, flags=40962, parent=0x555556f98cd0, child_class=0x555556b1d6a0 <child_of_bds>, child_role=19, errp=0x7fffffffda90) at ../block.c:3779 options=0x555556f9cfc0, bdref_key=0x555556239bb8 "file", parent=0x555556f98cd0, child_class=0x555556b1d6a0 <child_of_bds>, child_role=19, allow_none=true, errp=0x7fffffffda90) at ../block.c:3419 reference=0x0, options=0x555556f9cfc0, flags=8194, parent=0x0, child_class=0x0, child_role=0, errp=0x555556c98c40 <error_fatal>) at ../block.c:3726 options=0x555556f757b0, flags=0, errp=0x555556c98c40 <error_fatal>) at ../block.c:3872 options=0x555556f757b0, flags=0, errp=0x555556c98c40 <error_fatal>) at ../block/block-backend.c:436 bs_opts=0x555556f757b0, errp=0x555556c98c40 <error_fatal>) at ../blockdev.c:608 errp=0x555556c98c40 <error_fatal>) at ../blockdev.c:992 ...... Signed-off-by: Daniella Lee <daniellalee111@gmail.com> Message-Id: <20211119112553.352222-1-daniellalee111@gmail.com> [hreitz: Took commit message from v1] Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-11-16file-posix: Fix alignment after reopen changing O_DIRECTKevin Wolf1-4/+16
At the end of a reopen, we already call bdrv_refresh_limits(), which should update bs->request_alignment according to the new file descriptor. However, raw_probe_alignment() relies on s->needs_alignment and just uses 1 if it isn't set. We neglected to update this field, so starting with cache=writeback and then reopening with cache=none means that we get an incorrect bs->request_alignment == 1 and unaligned requests fail instead of being automatically aligned. Fix this by recalculating s->needs_alignment in raw_refresh_limits() before calling raw_probe_alignment(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20211104113109.56336-1-kwolf@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20211115145409.176785-13-kwolf@redhat.com> [hreitz: Fix iotest 142 for block sizes greater than 512 by operating on a file with a size of 1 MB] Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20211116101431.105252-1-hreitz@redhat.com>
2021-11-16stream: Traverse graph after modificationHanna Reitz1-2/+5
bdrv_cor_filter_drop() modifies the block graph. That means that other parties can also modify the block graph before it returns. Therefore, we cannot assume that the result of a graph traversal we did before remains valid afterwards. We should thus fetch `base` and `unfiltered_base` afterwards instead of before. Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211111120829.81329-2-hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20211115145409.176785-2-kwolf@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-11-03Merge remote-tracking branch 'remotes/kwolf/tags/for-upstream' into stagingRichard Henderson7-27/+171
Block layer patches - Fail gracefully when blockdev-snapshot creates loops - ide: Fix IDENTIFY DEVICE for disks > 128 GiB - file-posix: Fix return value translation for AIO discards - file-posix: add 'aio-max-batch' option - rbd: implement bdrv_co_block_status - Code cleanups and build fixes # gpg: Signature made Tue 02 Nov 2021 12:04:02 PM EDT # gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6 # gpg: issuer "kwolf@redhat.com" # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full] * remotes/kwolf/tags/for-upstream: block/nvme: Extract nvme_free_queue() from nvme_free_queue_pair() block/nvme: Display CQ/SQ pointer in nvme_free_queue_pair() block/nvme: Automatically free qemu_memalign() with QEMU_AUTO_VFREE block-backend: Silence clang -m32 compiler warning linux-aio: add `dev_max_batch` parameter to laio_io_unplug() linux-aio: add `dev_max_batch` parameter to laio_co_submit() file-posix: add `aio-max-batch` option block/export/fuse.c: fix musl build ide: Cap LBA28 capacity announcement to 2^28-1 block/rbd: implement bdrv_co_block_status block: Fail gracefully when blockdev-snapshot creates loops block/file-posix: Fix return value translation for AIO discards Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-11-02block/nvme: Extract nvme_free_queue() from nvme_free_queue_pair()Philippe Mathieu-Daudé1-2/+7
Instead of duplicating code, extract the common helper to free a single queue. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20211006164931.172349-4-philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02block/nvme: Display CQ/SQ pointer in nvme_free_queue_pair()Philippe Mathieu-Daudé2-2/+2
For debugging purpose it is helpful to know the CQ/SQ pointers. We already have a trace event in nvme_free_queue_pair(), extend it to report these pointer addresses. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20211006164931.172349-3-philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02block/nvme: Automatically free qemu_memalign() with QEMU_AUTO_VFREEPhilippe Mathieu-Daudé1-7/+4
Since commit 4d324c0bf65 ("introduce QEMU_AUTO_VFREE") buffers allocated by qemu_memalign() can automatically freed when using the QEMU_AUTO_VFREE macro. Use it to simplify a bit. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20211006164931.172349-2-philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02block-backend: Silence clang -m32 compiler warningHanna Reitz1-1/+1
Similarly to e7e588d432d31ecebc26358e47201dd108db964c, there is a warning in block/block-backend.c that qiov->size <= INT64_MAX is always true on machines where size_t is narrower than a uint64_t. In said commit, we silenced this warning by casting to uint64_t. The commit introducing this warning here (a93d81c84afa717b0a1a6947524d8d1fbfd6bbf5) anticipated it and so tried to address it the same way. However, it only did so in one of two places where this comparison occurs, and so we still need to fix up the other one. Fixes: a93d81c84afa717b0a1a6947524d8d1fbfd6bbf5 ("block-backend: convert blk_aio_ functions to int64_t bytes paramter") Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20211026090745.30800-1-hreitz@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02linux-aio: add `dev_max_batch` parameter to laio_io_unplug()Stefano Garzarella2-4/+6
Between the submission of a request and the unplug, other devices with larger limits may have been queued new requests without flushing the batch. Using the new `dev_max_batch` parameter, laio_io_unplug() can check if the batch exceeds the device limit to flush the current batch. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Message-Id: <20211026162346.253081-4-sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02linux-aio: add `dev_max_batch` parameter to laio_co_submit()Stefano Garzarella2-9/+24
This new parameter can be used by block devices to limit the Linux AIO batch size more than the limit set by the AIO context. file-posix backend supports this, passing its `aio-max-batch` option previously added. Add an helper function to calculate the maximum batch size. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Message-Id: <20211026162346.253081-3-sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02file-posix: add `aio-max-batch` optionStefano Garzarella1-0/+9
Commit d7ddd0a161 ("linux-aio: limit the batch size using `aio-max-batch` parameter") added a way to limit the batch size of Linux AIO backend for the entire AIO context. The same AIO context can be shared by multiple devices, so latency-sensitive devices may want to limit the batch size even more to avoid increasing latency. For this reason we add the `aio-max-batch` option to the file backend, which will be used by the next commits to limit the size of batches including requests generated by this device. Suggested-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Message-Id: <20211026162346.253081-2-sgarzare@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02block/export/fuse.c: fix musl buildFabrice Fontaine1-0/+4
Include linux/falloc.h if CONFIG_FALLOCATE_ZERO_RANGE is defined to fix https://gitlab.com/qemu-project/qemu/-/commit/50482fda98bd62e072c30b7ea73c985c4e9d9bbb and avoid the following build failure on musl: ../block/export/fuse.c: In function 'fuse_fallocate': ../block/export/fuse.c:643:21: error: 'FALLOC_FL_ZERO_RANGE' undeclared (first use in this function) 643 | else if (mode & FALLOC_FL_ZERO_RANGE) { | ^~~~~~~~~~~~~~~~~~~~ Fixes: - http://autobuild.buildroot.org/results/be24433a429fda681fb66698160132c1c99bc53b Fixes: 50482fda98b ("block/export/fuse.c: fix musl build") Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> Message-Id: <20211022095209.1319671-1-fontaine.fabrice@gmail.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02block/rbd: implement bdrv_co_block_statusPeter Lieven1-0/+112
the qemu rbd driver currently lacks support for bdrv_co_block_status. This results mainly in incorrect progress during block operations (e.g. qemu-img convert with an rbd image as source). This patch utilizes the rbd_diff_iterate2 call from librbd to detect allocated and unallocated (all zero areas). To avoid querying the ceph OSDs for the answer this is only done if the image has the fast-diff feature which depends on the object-map and exclusive-lock features. In this case it is guaranteed that the information is present in memory in the librbd client and thus very fast. If fast-diff is not available all areas are reported to be allocated which is the current behaviour if bdrv_co_block_status is not implemented. Signed-off-by: Peter Lieven <pl@kamp.de> Message-Id: <20211012152231.24868-1-pl@kamp.de> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02block/file-posix: Fix return value translation for AIO discardsAri Sundholm1-2/+2
AIO discards regressed as a result of the following commit: 0dfc7af2 block/file-posix: Optimize for macOS When trying to run blkdiscard within a Linux guest, the request would fail, with some errors in dmesg: ---- [ snip ] ---- [ 4.010070] sd 2:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 4.011061] sd 2:0:0:0: [sda] tag#0 Sense Key : Aborted Command [current] [ 4.011061] sd 2:0:0:0: [sda] tag#0 Add. Sense: I/O process terminated [ 4.011061] sd 2:0:0:0: [sda] tag#0 CDB: Unmap/Read sub-channel 42 00 00 00 00 00 00 00 18 00 [ 4.011061] blk_update_request: I/O error, dev sda, sector 0 ---- [ snip ] ---- This turns out to be a result of a flaw in changes to the error value translation logic in handle_aiocb_discard(). The default return value may be left untranslated in some configurations, and the wrong variable is used in one translation. Fix both issues. Fixes: 0dfc7af2b28 ("block/file-posix: Optimize for macOS") Cc: qemu-stable@nongnu.org Signed-off-by: Ari Sundholm <ari@tuxera.com> Signed-off-by: Emil Karlson <jkarlson@tuxera.com> Reviewed-by: Akihiko Odaki <akihiko.odaki@gmail.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20211019110954.4170931-1-ari@tuxera.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-11-02block/vpc: Add a sanity check that fixed-size images have the right typeThomas Huth1-1/+2
The code in vpc.c uses BDRVVPCState->footer.type in various places to decide whether the image is a fixed-size (VHD_FIXED) or a dynamic (VHD_DYNAMIC) image. However, we never check that this field really contains VHD_FIXED if we detected a fixed size image in vpc_open(), so a wrong value here could cause quite some trouble during runtime. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20211012082702.792259-1-thuth@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-11-02vmdk: allow specification of tools versionThomas Weißschuh1-4/+20
VMDK files support an attribute that represents the version of the guest tools that are installed on the disk. This attribute is used by vSphere before a machine has been started to determine if the VM has the guest tools installed. This is important when configuring "Operating system customizations" in vSphere, as it checks for the presence of the guest tools before allowing those customizations. Thus when the VM has not yet booted normally it would be impossible to customize it, therefore preventing a customized first-boot. The attribute should not hurt on disks that do not have the guest tools installed and indeed the VMware tools also unconditionally add this attribute. (Defaulting to the value "2147483647", as is done in this patch) Signed-off-by: Thomas Weißschuh <thomas.weissschuh.ext@zeiss.com> Message-Id: <20210913130419.13241-1-thomas.weissschuh.ext@zeiss.com> [hreitz: Added missing '#' in block-core.json] Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-10-15block-backend: drop INT_MAX restriction from blk_check_byte_request()Vladimir Sementsov-Ogievskiy1-1/+1
blk_check_bytes_request is called from blk_co_do_preadv, blk_co_do_pwritev_part, blk_co_do_pdiscard and blk_co_copy_range before (maybe) calling throttle_group_co_io_limits_intercept() (which has int64_t argument) and then calling corresponding bdrv_co_ function. bdrv_co_ functions are OK with int64_t bytes as well. So dropping the check for INT_MAX we just get same restrictions as in bdrv_ layer: discard and write-zeroes goes through bdrv_check_qiov_request() and are allowed to be 64bit. Other requests go through bdrv_check_request32() and still restricted by INT_MAX boundary. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-13-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: blk_pread, blk_pwrite: rename count parameter to bytesVladimir Sementsov-Ogievskiy1-8/+8
To be consistent with declarations in include/sysemu/block-backend.h. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-12-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: convert blk_aio_ functions to int64_t bytes paramterVladimir Sementsov-Ogievskiy1-5/+8
1. Convert bytes in BlkAioEmAIOCB: aio->bytes is only passed to already int64_t interfaces, and set in blk_aio_prwv, which is updated here. 2. For all updated functions the parameter type becomes wider so callers are safe. 3. In blk_aio_prwv we only store bytes to BlkAioEmAIOCB, which is updated here. 4. Other updated functions are wrappers on blk_aio_prwv. Note that blk_aio_preadv and blk_aio_pwritev become safer: before this commit, it's theoretically possible to pass qiov with size exceeding INT_MAX, which than converted to int argument of blk_aio_prwv. Now it's converted to int64_t which is a lot better. Still add assertions. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-11-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: tweak assertion and grammar] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: convert blk_co_copy_range to int64_t bytesVladimir Sementsov-Ogievskiy1-1/+1
Function is updated so that parameter type becomes wider, so all callers should be OK with it. Look at blk_co_copy_range() itself: bytes is passed only to blk_check_byte_request() and bdrv_co_copy_range(), which already have int64_t bytes parameter, so we are OK. Note that requests exceeding INT_MAX are still restricted by blk_check_byte_request(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-10-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar tweaks] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: convert blk_foo wrappers to use int64_t bytes parameterVladimir Sementsov-Ogievskiy1-5/+5
Convert blk_pdiscard, blk_pwrite_compressed, blk_pwrite_zeroes. These are just wrappers for functions with int64_t argument, so allow passing int64_t as well. Parameter type becomes wider so all callers should be OK with it. Note that requests exceeding INT_MAX are still restricted by blk_check_byte_request(). Note also that we don't (and are not going to) convert blk_pwrite and blk_pread: these functions return number of bytes on success, so to update them, we should change return type to int64_t as well, which will lead to investigating and updating all callers which is too much. So, blk_pread and blk_pwrite remain unchanged. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-9-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar tweaks] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: drop blk_prw, use block-coroutine-wrapperVladimir Sementsov-Ogievskiy2-93/+88
Let's drop hand-made coroutine wrappers and use coroutine wrapper generation like in block/io.c. Now, blk_foo() functions are written in same way as blk_co_foo() ones, but wrap blk_do_foo() instead of blk_co_do_foo(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-8-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: spelling fix] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-coroutine-wrapper.py: support BlockBackend first argumentVladimir Sementsov-Ogievskiy1-0/+3
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-7-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: rename _do_ helper functions to _co_do_Vladimir Sementsov-Ogievskiy1-26/+26
This is a preparation to the following commit, to use automatic coroutine wrapper generation. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-6-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: convert blk_co_pdiscard to int64_t bytesVladimir Sementsov-Ogievskiy1-2/+3
We updated blk_do_pdiscard() and its wrapper blk_co_pdiscard(). Both functions are updated so that the parameter type becomes wider, so all callers should be OK with it. Look at blk_do_pdiscard(): bytes is passed only to blk_check_byte_request() and bdrv_co_pdiscard(), which already have int64_t bytes parameter, so we are OK. Note that requests exceeding INT_MAX are still restricted by blk_check_byte_request(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-5-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar tweaks] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: convert blk_co_pwritev_part to int64_t bytesVladimir Sementsov-Ogievskiy2-5/+5
We convert blk_do_pwritev_part() and some wrappers: blk_co_pwritev_part(), blk_co_pwritev(), blk_co_pwrite_zeroes(). All functions are converted so that the parameter type becomes wider, so all callers should be OK with it. Look at blk_do_pwritev_part() body: bytes is passed to: - trace_blk_co_pwritev (we update it here) - blk_check_byte_request, throttle_group_co_io_limits_intercept, bdrv_co_pwritev_part - all already have int64_t argument. Note that requests exceeding INT_MAX are still restricted by blk_check_byte_request(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar tweaks] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: make blk_co_preadv() 64bitVladimir Sementsov-Ogievskiy2-3/+3
For both updated functions, the type of bytes becomes wider, so all callers should be OK with it. blk_co_preadv() only passes its arguments to blk_do_preadv(). blk_do_preadv() passes bytes to: - trace_blk_co_preadv, which is updated too - blk_check_byte_request, throttle_group_co_io_limits_intercept, bdrv_co_preadv, which are already int64_t. Note that requests exceeding INT_MAX are still restricted by blk_check_byte_request(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-3-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar tweaks] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15block-backend: blk_check_byte_request(): int64_t bytesVladimir Sementsov-Ogievskiy1-3/+3
Rename size and make it int64_t to correspond to modern block layer, which always uses int64_t for offset and bytes (not in blk layer yet, which is a task for following commits). All callers pass int or unsigned int. So, for bytes in [0, INT_MAX] nothing is changed, for negative bytes we now fail on "bytes < 0" check instead of "bytes > INT_MAX" check. Note, that blk_check_byte_request() still doesn't allow requests exceeding INT_MAX. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006131718.214235-2-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-15qcow2: Silence clang -m32 compiler warningHanna Reitz1-1/+2
With -m32, size_t is generally only a uint32_t. That makes clang complain that in the assertion assert(qiov->size <= INT64_MAX); the range of the type of qiov->size (size_t) is too small for any of its values to ever exceed INT64_MAX. Cast qiov->size to uint64_t to silence clang. Fixes: f7ef38dd1310d7d9db76d0aa16899cbc5744f36d ("block: use int64_t instead of uint64_t in driver read handlers") Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20211011155031.149158-1-hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-10-14configure, meson: move libaio check to meson.buildPaolo Bonzini1-1/+1
Message-Id: <20211007130829.632254-10-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-07Merge remote-tracking branch ↵Richard Henderson4-29/+40
'remotes/vsementsov/tags/pull-jobs-2021-10-07-v2' into staging mirror: Handle errors after READY cancel v2: add small fix by Stefano, Hanna's series fixed # gpg: Signature made Thu 07 Oct 2021 08:25:07 AM PDT # gpg: using RSA key 8B9C26CDB2FD147C880E86A1561F24C1F19F79FB # gpg: Good signature from "Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>" [unknown] # gpg: WARNING: This key is not certified with a trusted signature! # gpg: There is no indication that the signature belongs to the owner. # Primary key fingerprint: 8B9C 26CD B2FD 147C 880E 86A1 561F 24C1 F19F 79FB * remotes/vsementsov/tags/pull-jobs-2021-10-07-v2: iotests: Add mirror-ready-cancel-error test mirror: Do not clear .cancelled mirror: Stop active mirroring after force-cancel mirror: Check job_is_cancelled() earlier mirror: Use job_is_cancelled() job: Add job_cancel_requested() job: Do not soft-cancel after a job is done jobs: Give Job.force_cancel more meaning job: @force parameter for job_cancel_sync() job: Force-cancel jobs in a failed transaction mirror: Drop s->synced mirror: Keep s->synced on error job: Context changes in job_completed_txn_abort() block/aio_task: assert `max_busy_tasks` is greater than 0 block/backup: avoid integer overflow of `max-workers` Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-10-07mirror: Do not clear .cancelledHanna Reitz1-2/+0
Clearing .cancelled before leaving the main loop when the job has been soft-cancelled is no longer necessary since job_is_cancelled() only returns true for jobs that have been force-cancelled. Therefore, this only makes a differences in places that call job_cancel_requested(). In block/mirror.c, this is done only before .cancelled was cleared. In job.c, there are two callers: - job_completed_txn_abort() asserts that .cancelled is true, so keeping it true will not affect this place. - job_complete() refuses to let a job complete that has .cancelled set. It is correct to refuse to let the user invoke job-complete on mirror jobs that have already been soft-cancelled. With this change, there are no places that reset .cancelled to false and so we can be sure that .force_cancel can only be true if .cancelled is true as well. Assert this in job_is_cancelled(). Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006151940.214590-13-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-07mirror: Stop active mirroring after force-cancelHanna Reitz1-0/+2
Once the mirror job is force-cancelled (job_is_cancelled() is true), we should not generate new I/O requests. This applies to active mirroring, too, so stop it once the job is cancelled. (We must still forward all I/O requests to the source, though, of course, but those are not really I/O requests generated by the job, so this is fine.) Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006151940.214590-12-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-07mirror: Check job_is_cancelled() earlierHanna Reitz1-5/+5
We must check whether the job is force-cancelled early in our main loop, most importantly before any `continue` statement. For example, we used to have `continue`s before our current checking location that are triggered by `mirror_flush()` failing. So, if `mirror_flush()` kept failing, force-cancelling the job would not terminate it. Jobs can be cancelled while they yield, and once they are (force-cancelled), they should not generate new I/O requests. Therefore, we should put the check after the last yield before mirror_iteration() is invoked. Buglink: https://gitlab.com/qemu-project/qemu/-/issues/462 Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006151940.214590-11-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-07mirror: Use job_is_cancelled()Hanna Reitz1-1/+1
mirror_drained_poll() returns true whenever the job is cancelled, because "we [can] be sure that it won't issue more requests". However, this is only true for force-cancelled jobs, so use job_is_cancelled(). Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006151940.214590-10-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-07job: Add job_cancel_requested()Hanna Reitz1-6/+4
Most callers of job_is_cancelled() actually want to know whether the job is on its way to immediate termination. For example, we refuse to pause jobs that are cancelled; but this only makes sense for jobs that are really actually cancelled. A mirror job that is cancelled during READY with force=false should absolutely be allowed to pause. This "cancellation" (which is actually a kind of completion) may take an indefinite amount of time, and so should behave like any job during normal operation. For example, with on-target-error=stop, the job should stop on write errors. (In contrast, force-cancelled jobs should not get write errors, as they should just terminate and not do further I/O.) Therefore, redefine job_is_cancelled() to only return true for jobs that are force-cancelled (which as of HEAD^ means any job that interprets the cancellation request as a request for immediate termination), and add job_cancel_requested() as the general variant, which returns true for any jobs which have been requested to be cancelled, whether it be immediately or after an arbitrarily long completion phase. Finally, here is a justification for how different job_is_cancelled() invocations are treated by this patch: - block/mirror.c (mirror_run()): - The first invocation is a while loop that should loop until the job has been cancelled or scheduled for completion. What kind of cancel does not matter, only the fact that the job is supposed to end. - The second invocation wants to know whether the job has been soft-cancelled. Calling job_cancel_requested() is a bit too broad, but if the job were force-cancelled, we should leave the main loop as soon as possible anyway, so this should not matter here. - The last two invocations already check force_cancel, so they should continue to use job_is_cancelled(). - block/backup.c, block/commit.c, block/stream.c, anything in tests/: These jobs know only force-cancel, so there is no difference between job_is_cancelled() and job_cancel_requested(). We can continue using job_is_cancelled(). - job.c: - job_pause_point(), job_yield(), job_sleep_ns(): Only force-cancelled jobs should be prevented from being paused. Continue using job_is_cancelled(). - job_update_rc(), job_finalize_single(), job_finish_sync(): These functions are all called after the job has left its main loop. The mirror job (the only job that can be soft-cancelled) will clear .cancelled before leaving the main loop if it has been soft-cancelled. Therefore, these functions will observe .cancelled to be true only if the job has been force-cancelled. We can continue to use job_is_cancelled(). (Furthermore, conceptually, a soft-cancelled mirror job should not report to have been cancelled. It should report completion (see also the block-job-cancel QAPI documentation). Therefore, it makes sense for these functions not to distinguish between a soft-cancelled mirror job and a job that has completed as normal.) - job_completed_txn_abort(): All jobs other than @job have been force-cancelled. job_is_cancelled() must be true for them. Regarding @job itself: job_completed_txn_abort() is mostly called when the job's return value is not 0. A soft-cancelled mirror has a return value of 0, and so will not end up here then. However, job_cancel() invokes job_completed_txn_abort() if the job has been deferred to the main loop, which is mostly the case for completed jobs (which skip the assertion), but not for sure. To be safe, use job_cancel_requested() in this assertion. - job_complete(): This is function eventually invoked by the user (through qmp_block_job_complete() or qmp_job_complete(), or job_complete_sync(), which comes from qemu-img). The intention here is to prevent a user from invoking job-complete after the job has been cancelled. This should also apply to soft cancelling: After a mirror job has been soft-cancelled, the user should not be able to decide otherwise and have it complete as normal (i.e. pivoting to the target). - job_cancel(): Both functions are equivalent (see comment there), but we want to use job_is_cancelled(), because this shows that we call job_completed_txn_abort() only for force-cancelled jobs. (As explained for job_update_rc(), soft-cancelled jobs should be treated as if they have completed as normal.) Buglink: https://gitlab.com/qemu-project/qemu/-/issues/462 Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006151940.214590-9-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-07jobs: Give Job.force_cancel more meaningHanna Reitz2-7/+20
We largely have two cancel modes for jobs: First, there is actual cancelling. The job is terminated as soon as possible, without trying to reach a consistent result. Second, we have mirror in the READY state. Technically, the job is not really cancelled, but it just is a different completion mode. The job can still run for an indefinite amount of time while it tries to reach a consistent result. We want to be able to clearly distinguish which cancel mode a job is in (when it has been cancelled). We can use Job.force_cancel for this, but right now it only reflects cancel requests from the user with force=true, but clearly, jobs that do not even distinguish between force=false and force=true are effectively always force-cancelled. So this patch has Job.force_cancel signify whether the job will terminate as soon as possible (force_cancel=true) or whether it will effectively remain running despite being "cancelled" (force_cancel=false). To this end, we let jobs that provide JobDriver.cancel() tell the generic job code whether they will terminate as soon as possible or not, and for jobs that do not provide that method we assume they will. Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20211006151940.214590-7-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-07job: @force parameter for job_cancel_sync()Hanna Reitz1-2/+2
Callers should be able to specify whether they want job_cancel_sync() to force-cancel the job or not. In fact, almost all invocations do not care about consistency of the result and just want the job to terminate as soon as possible, so they should pass force=true. The replication block driver is the exception, specifically the active commit job it runs. As for job_cancel_sync_all(), all callers want it to force-cancel all jobs, because that is the point of it: To cancel all remaining jobs as quickly as possible (generally on process termination). So make it invoke job_cancel_sync() with force=true. This changes some iotest outputs, because quitting qemu while a mirror job is active will now lead to it being cancelled instead of completed, which is what we want. (Cancelling a READY mirror job with force=false may take an indefinite amount of time, which we do not want when quitting. If users want consistent results, they must have all jobs be done before they quit qemu.) Buglink: https://gitlab.com/qemu-project/qemu/-/issues/462 Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006151940.214590-6-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-07mirror: Drop s->syncedHanna Reitz1-10/+9
As of HEAD^, there is no meaning to s->synced other than whether the job is READY or not. job_is_ready() gives us that information, too. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20211006151940.214590-4-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-07mirror: Keep s->synced on errorHanna Reitz1-1/+0
An error does not take us out of the READY phase, which is what s->synced signifies. It does of course mean that source and target are no longer in sync, but that is what s->actively_sync is for -- s->synced never meant that source and target are in sync, only that they were at some point (and at that point we transitioned into the READY phase). The tangible problem is that we transition to READY once we are in sync and s->synced is false. By resetting s->synced here, we will transition from READY to READY once the error is resolved (if the job keeps running), and that transition is not allowed. Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20211006151940.214590-3-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-06block: introduce max_hw_iov for use in scsi-genericPaolo Bonzini3-1/+8
Linux limits the size of iovecs to 1024 (UIO_MAXIOV in the kernel sources, IOV_MAX in POSIX). Because of this, on some host adapters requests with many iovecs are rejected with -EINVAL by the io_submit() or readv()/writev() system calls. In fact, the same limit applies to SG_IO as well. To fix both the EINVAL and the possible performance issues from using fewer iovecs than allowed by Linux (some HBAs have max_segments as low as 128), introduce a separate entry in BlockLimits to hold the max_segments value from sysfs. This new limit is used only for SG_IO and clamped to bs->bl.max_iov anyway, just like max_hw_transfer is clamped to bs->bl.max_transfer. Reported-by: Halil Pasic <pasic@linux.ibm.com> Cc: Hanna Reitz <hreitz@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: qemu-block@nongnu.org Cc: qemu-stable@nongnu.org Fixes: 18473467d5 ("file-posix: try BLKSECTGET on block devices too, do not round to power of 2", 2021-06-25) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210923130436.1187591-1-pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-10-05block/aio_task: assert `max_busy_tasks` is greater than 0Stefano Garzarella1-0/+2
All code in block/aio_task.c expects `max_busy_tasks` to always be greater than 0. Assert this condition during the AioTaskPool creation where `max_busy_tasks` is set. Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211005161157.282396-3-sgarzare@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-10-05block/backup: avoid integer overflow of `max-workers`Stefano Garzarella1-2/+2
QAPI generates `struct BackupPerf` where `max-workers` value is stored in an `int64_t` variable. But block_copy_async(), and the underlying code, uses an `int` parameter. At the end that variable is used to initialize `max_busy_tasks` in block/aio_task.c causing the following assertion failure if a value greater than INT_MAX(2147483647) is used: ../block/aio_task.c:63: aio_task_pool_wait_one: Assertion `pool->busy_tasks > 0' failed. Let's check that `max-workers` doesn't exceed INT_MAX and print an error in that case. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2009310 Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211005161157.282396-2-sgarzare@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-09-29block/nbd: check that received handle is validVladimir Sementsov-Ogievskiy1-8/+3
If we don't have active request, that waiting for this handle to be received, we should report an error. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210902103805.25686-6-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29block/nbd: drop connection_coVladimir Sementsov-Ogievskiy1-275/+100
OK, that's a big rewrite of the logic. Pre-patch we have an always running coroutine - connection_co. It does reply receiving and reconnecting. And it leads to a lot of difficult and unobvious code around drained sections and context switch. We also abuse bs->in_flight counter which is increased for connection_co and temporary decreased in points where we want to allow drained section to begin. One of these place is in another file: in nbd_read_eof() in nbd/client.c. We also cancel reconnect and requests waiting for reconnect on drained begin which is not correct. And this patch fixes that. Let's finally drop this always running coroutine and go another way: do both reconnect and receiving in request coroutines. The detailed list of changes below (in the sequence of diff hunks). 1. receiving coroutines are woken directly from nbd_channel_error, when we change s->state 2. nbd_co_establish_connection_cancel(): we don't have drain_begin now, and in nbd_teardown_connection() all requests should already be finished (and reconnect is done from request). So nbd_co_establish_connection_cancel() is called from nbd_cancel_in_flight() (to cancel the request that is doing nbd_co_establish_connection()) and from reconnect_delay_timer_cb() (previously we didn't need it, as reconnect delay only should cancel active requests not the reconnection itself). But now reconnection itself is done in the separate thread (we now call nbd_client_connection_enable_retry() in nbd_open()), and we need to cancel the requests that wait in nbd_co_establish_connection() now). 2A. We do receive headers in request coroutine. But we also should dispatch replies for other pending requests. So, nbd_connection_entry() is turned into nbd_receive_replies(), which does reply dispatching while it receives other request headers, and returns when it receives the requested header. 3. All old staff around drained sections and context switch is dropped. In details: - we don't need to move connection_co to new aio context, as we don't have connection_co anymore - we don't have a fake "request" of connection_co (extra increasing in_flight), so don't care with it in drain_begin/end - we don't stop reconnection during drained section anymore. This means that drain_begin may wait for a long time (up to reconnect_delay). But that's an improvement and more correct behavior see below[*] 4. In nbd_teardown_connection() we don't have to wait for connection_co, as it is dropped. And cleanup for s->ioc and nbd_yank is moved here from removed connection_co. 5. In nbd_co_do_establish_connection() we now should handle NBD_CLIENT_CONNECTING_NOWAIT: if new request comes when we are in NBD_CLIENT_CONNECTING_NOWAIT, it still should call nbd_co_establish_connection() (who knows, maybe the connection was already established by another thread in the background). But we shouldn't wait: if nbd_co_establish_connection() can't return new channel immediately the request should fail (we are in NBD_CLIENT_CONNECTING_NOWAIT state). 6. nbd_reconnect_attempt() is simplified: it's now easier to wait for other requests in the caller, so here we just assert that fact. Also delay time is now initialized here: we can easily detect first attempt and start a timer. 7. nbd_co_reconnect_loop() is dropped, we don't need it. Reconnect retries are fully handle by thread (nbd/client-connection.c), delay timer we initialize in nbd_reconnect_attempt(), we don't have to bother with s->drained and friends. nbd_reconnect_attempt() now called from nbd_co_send_request(). 8. nbd_connection_entry is dropped: reconnect is now handled by nbd_co_send_request(), receiving reply is now handled by nbd_receive_replies(): all handled from request coroutines. 9. So, welcome new nbd_receive_replies() called from request coroutine, that receives reply header instead of nbd_connection_entry(). Like with sending requests, only one coroutine may receive in a moment. So we introduce receive_mutex, which is locked around nbd_receive_reply(). It also protects some related fields. Still, full audit of thread-safety in nbd driver is a separate task. New function waits for a reply with specified handle being received and works rather simple: Under mutex: - if current handle is 0, do receive by hand. If another handle received - switch to other request coroutine, release mutex and yield. Otherwise return success - if current handle == requested handle, we are done - otherwise, release mutex and yield 10: in nbd_co_send_request() we now do nbd_reconnect_attempt() if needed. Also waiting in free_sema queue we now wait for one of two conditions: - connectED, in_flight < MAX_NBD_REQUESTS (so we can start new one) - connectING, in_flight == 0, so we can call nbd_reconnect_attempt() And this logic is protected by s->send_mutex Also, on failure we don't have to care of removed s->connection_co 11. nbd_co_do_receive_one_chunk(): now instead of yield() and wait for s->connection_co we just call new nbd_receive_replies(). 12. nbd_co_receive_one_chunk(): place where s->reply.handle becomes 0, which means that handling of the whole reply is finished. Here we need to wake one of coroutines sleeping in nbd_receive_replies(). If none are sleeping - do nothing. That's another behavior change: we don't have endless recv() in the idle time. It may be considered as a drawback. If so, it may be fixed later. 13. nbd_reply_chunk_iter_receive(): don't care about removed connection_co, just ping in_flight waiters. 14. Don't create connection_co, enable retry in the connection thread (we don't have own reconnect loop anymore) 15. We now need to add a nbd_co_establish_connection_cancel() call in nbd_cancel_in_flight(), to cancel the request that is doing a connection attempt. [*], ok, now we don't cancel reconnect on drain begin. That's correct: reconnect feature leads to possibility of long-running requests (up to reconnect delay). Still, drain begin is not a reason to kill long requests. We should wait for them. This also means, that we can again reproduce a dead-lock, described in 8c517de24a8a1dcbeb54e7e12b5b0fda42a90ace. Why we are OK with it: 1. Now this is not absolutely-dead dead-lock: the vm is unfrozen after reconnect delay. Actually 8c517de24a8a1dc fixed a bug in NBD logic, that was not described in 8c517de24a8a1dc and led to forever dead-lock. The problem was that nobody woke the free_sema queue, but drain_begin can't finish until there is a request in free_sema queue. Now we have a reconnect delay timer that works well. 2. It's not a problem of the NBD driver, but of the ide code, because it does drain_begin under the global mutex; the problem doesn't reproduce when using scsi instead of ide. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210902103805.25686-5-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar and comment tweaks] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29block/nbd: refactor nbd_recv_coroutines_wake_all()Vladimir Sementsov-Ogievskiy1-9/+17
Split out nbd_recv_coroutine_wake_one(), as it will be used separately. Rename the function and add a possibility to wake only first found sleeping coroutine. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210902103805.25686-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar tweak] Signed-off-by: Eric Blake <eblake@redhat.com>