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2020-10-30block: Return depth level during bdrv_is_allocated_aboveEric Blake1-8/+23
When checking for allocation across a chain, it's already easy to count the depth within the chain at which the allocation is found. Instead of throwing that information away, return it to the caller. Existing callers only cared about allocated/non-allocated, but having a depth available will be used by NBD in the next patch. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20201027050556.269064-9-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> [eblake: rebase to master] Signed-off-by: Eric Blake <eblake@redhat.com>
2020-10-27block: End quiescent sections when a BDS is deletedGreg Kurz1-0/+13
If a BDS gets deleted during blk_drain_all(), it might miss a call to bdrv_do_drained_end(). This means missing a call to aio_enable_external() and the AIO context remains disabled for ever. This can cause a device to become irresponsive and to disrupt the guest execution, ie. hang, loop forever or worse. This scenario is quite easy to encounter with virtio-scsi on POWER when punching multiple blockdev-create QMP commands while the guest is booting and it is still running the SLOF firmware. This happens because SLOF disables/re-enables PCI devices multiple times via IO/MEM/MASTER bits of PCI_COMMAND register after the initial probe/feature negotiation, as it tends to work with a single device at a time at various stages like probing and running block/network bootloaders without doing a full reset in-between. This naturally generates many dataplane stops and starts, and thus many drain sections that can race with blockdev_create_run(). In the end, SLOF bails out. It is somehow reproducible on x86 but it requires to generate articial dataplane start/stop activity with stop/cont QMP commands. In this case, seabios ends up looping for ever, waiting for the virtio-scsi device to send a response to a command it never received. Add a helper that pairs all previously called bdrv_do_drained_begin() with a bdrv_do_drained_end() and call it from bdrv_close(). While at it, update the "/bdrv-drain/graph-change/drain_all" test in test-bdrv-drain so that it can catch the issue. BugId: https://bugzilla.redhat.com/show_bug.cgi?id=1874441 Signed-off-by: Greg Kurz <groug@kaod.org> Message-Id: <160346526998.272601.9045392804399803158.stgit@bahia.lan> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-27qcow2: Skip copy-on-write when allocating a zero clusterAlberto Garcia1-0/+27
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>
2020-10-27qcow2: Report BDRV_BLOCK_ZERO more accurately in bdrv_co_block_status()Alberto Garcia1-4/+4
If a BlockDriverState supports backing files but has none then any unallocated area reads back as zeroes. bdrv_co_block_status() is only reporting this is if want_zero is true, but this is an inexpensive test and there is no reason not to do it in all cases. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <66fa0914a0e2b727ab6d1b63ca773d7cd29a9a9e.1603731354.git.berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-23block/io: fix bdrv_is_allocated_aboveVladimir Sementsov-Ogievskiy1-38/+5
bdrv_is_allocated_above wrongly handles short backing files: it reports after-EOF space as UNALLOCATED which is wrong, as on read the data is generated on the level of short backing file (if all overlays have unallocated areas at that place). Reusing bdrv_common_block_status_above fixes the issue and unifies code path. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20200924194003.22080-5-vsementsov@virtuozzo.com [Fix s/has/have/ as suggested by Eric Blake. Fix s/area/areas/. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23block/io: bdrv_common_block_status_above: support bs == baseVladimir Sementsov-Ogievskiy1-1/+5
We are going to reuse bdrv_common_block_status_above in bdrv_is_allocated_above. bdrv_is_allocated_above may be called with include_base == false and still bs == base (for ex. from img_rebase()). So, support this corner case. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20200924194003.22080-4-vsementsov@virtuozzo.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23block/io: bdrv_common_block_status_above: support include_baseVladimir Sementsov-Ogievskiy1-7/+14
In order to reuse bdrv_common_block_status_above in bdrv_is_allocated_above, let's support include_base parameter. 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: 20200924194003.22080-3-vsementsov@virtuozzo.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23block/io: fix bdrv_co_block_status_aboveVladimir Sementsov-Ogievskiy1-14/+54
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>
2020-10-05block/io: refactor save/load vmstateVladimir Sementsov-Ogievskiy1-33/+35
Like for read/write in a previous commit, drop extra indirection layer, generate directly bdrv_readv_vmstate() and bdrv_writev_vmstate(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-8-vsementsov@virtuozzo.com>
2020-10-05block: drop bdrv_prwvVladimir Sementsov-Ogievskiy1-40/+9
Now that we are not maintaining boilerplate code for coroutine wrappers, there is no more sense in keeping the extra indirection layer of bdrv_prwv(). Let's drop it and instead generate pure bdrv_preadv() and bdrv_pwritev(). Currently, bdrv_pwritev() and bdrv_preadv() are returning bytes on success, auto generated functions will instead return zero, as their _co_ prototype. Still, it's simple to make the conversion safe: the only external user of bdrv_pwritev() is test-bdrv-drain, and it is comfortable enough with bdrv_co_pwritev() instead. So prototypes are moved to local block/coroutines.h. Next, the only internal use is bdrv_pread() and bdrv_pwrite(), which are modified to return bytes on success. Of course, it would be great to convert bdrv_pread() and bdrv_pwrite() to return 0 on success. But this requires audit (and probably conversion) of all their users, let's leave it for another day refactoring. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-7-vsementsov@virtuozzo.com>
2020-10-05block: generate coroutine-wrapper codeVladimir Sementsov-Ogievskiy1-212/+0
Use code generation implemented in previous commit to generated coroutine wrappers in block.c and block/io.c Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-6-vsementsov@virtuozzo.com>
2020-10-05block: declare some coroutine functions in block/coroutines.hVladimir Sementsov-Ogievskiy1-17/+17
We are going to keep coroutine-wrappers code (structure-packing parameters, BDRV_POLL wrapper functions) in separate auto-generated files. So, we'll need a header with declaration of original _co_ functions, for those which are static now. As well, we'll need declarations for wrapper functions. Do these declarations now, as a preparation step. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-4-vsementsov@virtuozzo.com>
2020-10-05block/io: refactor coroutine wrappersVladimir Sementsov-Ogievskiy1-28/+32
Most of our coroutine wrappers already follow this convention: We have 'coroutine_fn bdrv_co_<something>(<normal argument list>)' as the core function, and a wrapper 'bdrv_<something>(<same argument list>)' which does parameter packing and calls bdrv_run_co(). The only outsiders are the bdrv_prwv_co and bdrv_common_block_status_above wrappers. Let's refactor them to behave as the others, it simplifies further conversion of coroutine wrappers. This patch adds an indirection layer, but it will be compensated by a further commit, which will drop bdrv_co_prwv together with the is_write logic, to keep the read and write paths separate. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-3-vsementsov@virtuozzo.com>
2020-09-23qemu/atomic.h: rename atomic_ to qatomic_Stefan Hajnoczi1-24/+24
clang's C11 atomic_fetch_*() functions only take a C11 atomic type pointer argument. QEMU uses direct types (int, etc) and this causes a compiler error when a QEMU code calls these functions in a source file that also included <stdatomic.h> via a system header file: $ CC=clang CXX=clang++ ./configure ... && make ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid) Avoid using atomic_*() names in QEMU's atomic.h since that namespace is used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h and <stdatomic.h> can co-exist. I checked /usr/include on my machine and searched GitHub for existing "qatomic_" users but there seem to be none. This patch was generated using: $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \ sort -u >/tmp/changed_identifiers $ for identifier in $(</tmp/changed_identifiers); do sed -i "s%\<$identifier\>%q$identifier%g" \ $(git grep -I -l "\<$identifier\>") done I manually fixed line-wrap issues and misaligned rST tables. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-09-07block: Inline bdrv_co_block_status_from_*()Max Reitz1-34/+17
With bdrv_filter_bs(), we can easily handle this default filter behavior in bdrv_co_block_status(). blkdebug wants to have an additional assertion, so it keeps its own implementation, except bdrv_co_block_status_from_file() needs to be inlined there. Suggested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07block: Use CAF in bdrv_co_rw_vmstate()Max Reitz1-2/+3
If a node whose driver does not provide VM state functions has a metadata child, the VM state should probably go there; if it is a filter, the VM state should probably go there. It follows that we should generally go down to the primary child. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07block: Iterate over children in refresh_limitsMax Reitz1-16/+16
Instead of looking at just bs->file and bs->backing, we should look at all children that could end up receiving forwarded requests. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07block: Flush all children in generic codeMax Reitz1-6/+17
If the driver does not support .bdrv_co_flush() so bdrv_co_flush() itself has to flush the children of the given node, it should not flush just bs->file->bs, but in fact all children that might have been written to (judging from the permissions taken on them). This is a bug fix for qcow2 images with an external data file, as they so far did not flush that data_file node. In any case, the BLKDBG_EVENT() should be emitted on the primary child, because that is where a blkdebug node would be if there is any. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07block: Use bdrv_cow_child() in bdrv_co_truncate()Max Reitz1-3/+4
The condition modified here is not about potentially filtered children, but only about COW sources (i.e. traditional backing files). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07block: Use CAFs in block status functionsMax Reitz1-9/+10
Use the child access functions in the block status inquiry functions as appropriate. Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07block: Use bdrv_filter_(bs|child) where obviousMax Reitz1-2/+5
Places that use patterns like if (bs->drv->is_filter && bs->file) { ... something about bs->file->bs ... } should be BlockDriverState *filtered = bdrv_filter_bs(bs); if (filtered) { ... something about @filtered ... } instead. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-07-28block: Fix bdrv_aligned_p*v() for qiov_offset != 0Max Reitz1-4/+6
Since these functions take a @qiov_offset, they must always take it into account when working with @qiov. There are a couple of places where they do not, but they should. Fixes: 65cd4424b9df03bb5195351c33e04cbbecc0705c ("block/io: bdrv_aligned_preadv: use and support qiov_offset") Fixes: 28c4da28695bdbe04b336b2c9c463876cc3aaa6d ("block/io: bdrv_aligned_pwritev: use and support qiov_offset") Reported-by: Claudio Fontana <cfontana@suse.de> Reported-by: Bruce Rogers <brogers@suse.com> Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200728120806.265916-2-mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Tested-by: Claudio Fontana <cfontana@suse.de> Tested-by: Bruce Rogers <brogers@suse.com>
2020-07-06block: drop unallocated_blocks_are_zeroVladimir Sementsov-Ogievskiy1-7/+2
Currently this field only set by qed and qcow2. But in fact, all backing-supporting formats (parallels, qcow, qcow2, qed, vmdk) share these semantics: on unallocated blocks, if there is no backing file they just memset the buffer with zeroes. So, document this behavior for .supports_backing and drop .unallocated_blocks_are_zero Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200528094405.145708-10-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06block: inline bdrv_unallocated_blocks_are_zero()Vladimir Sementsov-Ogievskiy1-3/+8
The function has only one user: bdrv_co_block_status(). Inline it to simplify reviewing of the following patches, which will finally drop unallocated_blocks_are_zero field too. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200528094405.145708-3-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-06-05block: Factor out bdrv_run_co()Vladimir Sementsov-Ogievskiy1-121/+72
We have a few bdrv_*() functions that can either spawn a new coroutine and wait for it with BDRV_POLL_WHILE() or use a fastpath if they are alreeady running in a coroutine. All of them duplicate basically the same code. Factor the common code into a new function bdrv_run_co(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20200520144901.16589-1-vsementsov@virtuozzo.com [Factor out bdrv_run_co_entry too] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-05-18block: Rename BdrvChildRole to BdrvChildClassMax Reitz1-11/+11
This structure nearly only contains parent callbacks for child state changes. It cannot really reflect a child's role, because different roles may overlap (as we will see when real roles are introduced), and because parents can have custom callbacks even when the child fulfills a standard role. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200513110544.176672-4-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-05block: Comment cleanupsEric Blake1-1/+2
It's been a while since we got rid of the sector-based bdrv_read and bdrv_write (commit 2e11d756); let's finish the job on a few remaining comments. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428213807.776655-1-eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-04-30block: truncate: Don't make backing file data visibleKevin Wolf1-0/+25
When extending the size of an image that has a backing file larger than its old size, make sure that the backing file data doesn't become visible in the guest, but the added area is properly zeroed out. Consider the following scenario where the overlay is shorter than its backing file: base.qcow2: AAAAAAAA overlay.qcow2: BBBB When resizing (extending) overlay.qcow2, the new blocks should not stay unallocated and make the additional As from base.qcow2 visible like before this patch, but zeros should be read. A similar case happens with the various variants of a commit job when an intermediate file is short (- for unallocated): base.qcow2: A-A-AAAA mid.qcow2: BB-B top.qcow2: C--C--C- After commit top.qcow2 to mid.qcow2, the following happens: mid.qcow2: CB-C00C0 (correct result) mid.qcow2: CB-C--C- (before this fix) Without the fix, blocks that previously read as zeros on top.qcow2 suddenly turn into A. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200424125448.63318-8-kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30block: Add flags to bdrv(_co)_truncate()Kevin Wolf1-5/+7
Now that block drivers can support flags for .bdrv_co_truncate, expose the parameter in the node level interfaces bdrv_co_truncate() and bdrv_truncate(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200424125448.63318-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30block: Add flags to BlockDriver.bdrv_co_truncate()Kevin Wolf1-1/+7
This adds a new BdrvRequestFlags parameter to the .bdrv_co_truncate() driver callbacks, and a supported_truncate_flags field in BlockDriverState that allows drivers to advertise support for request flags in the context of truncate. For now, we always pass 0 and no drivers declare support for any flag. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200424125448.63318-2-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-16block/io: fix bdrv_co_do_copy_on_readvVladimir Sementsov-Ogievskiy1-1/+1
Prior to 1143ec5ebf4 it was OK to qemu_iovec_from_buf() from aligned-up buffer to original qiov, as qemu_iovec_from_buf() will stop at qiov end anyway. But after 1143ec5ebf4 we assume that bdrv_co_do_copy_on_readv works on part of original qiov, defined by qiov_offset and bytes. So we must not touch qiov behind qiov_offset+bytes bound. Fix it. Cc: qemu-stable@nongnu.org # v4.2 Fixes: 1143ec5ebf4 Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200312081949.5350-1-vsementsov@virtuozzo.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-02-07block: fix crash on zero-length unaligned write and readVladimir Sementsov-Ogievskiy1-1/+27
Commit 7a3f542fbd "block/io: refactor padding" occasionally dropped aligning for zero-length request: bdrv_init_padding() blindly return false if bytes == 0, like there is nothing to align. This leads the following command to crash: ./qemu-io --image-opts -c 'write 1 0' \ driver=blkdebug,align=512,image.driver=null-co,image.size=512 >> qemu-io: block/io.c:1955: bdrv_aligned_pwritev: Assertion `(offset & (align - 1)) == 0' failed. >> Aborted (core dumped) Prior to 7a3f542fbd we does aligning of such zero requests. Instead of recovering this behavior let's just do nothing on such requests as it is useless. Note that driver may have special meaning of zero-length reqeusts, like qcow2_co_pwritev_compressed_part, so we can't skip any zero-length operation. But for unaligned ones, we can't pass it to driver anyway. This commit also fixes crash in iotest 80 running with -nocache: ./check -nocache -qcow2 80 which crashes on same assertion due to trying to read empty extra data in qcow2_do_read_snapshots(). Cc: qemu-stable@nongnu.org # v4.2 Fixes: 7a3f542fbd Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20200206164245.17781-1-vsementsov@virtuozzo.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-30block/io: take bs->reqs_lock in bdrv_mark_request_serialisingPaolo Bonzini1-49/+63
bdrv_mark_request_serialising is writing the overlap_offset and overlap_bytes fields of BdrvTrackedRequest. Take bs->reqs_lock for the whole duration of it, and not just when waiting for serialising requests, so that tracked_request_overlaps does not look at a half-updated request. The new code does not unlock/relock around retries. This is unnecessary because a retry is always preceded by a CoQueue wait, which already releases and reacquires bs->reqs_lock. Reported-by: Peter Lieven <pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1578495356-46219-4-git-send-email-pbonzini@redhat.com Message-Id: <1578495356-46219-4-git-send-email-pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-30block/io: wait for serialising requests when a request becomes serialisingPaolo Bonzini1-23/+17
Marking without waiting would not result in actual serialising behavior. Thus, make a call bdrv_mark_request_serialising sufficient for serialisation to happen. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1578495356-46219-3-git-send-email-pbonzini@redhat.com Message-Id: <1578495356-46219-3-git-send-email-pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-30block: eliminate BDRV_REQ_NO_SERIALISINGPaolo Bonzini1-14/+4
It is unused since commit 00e30f0 ("block/backup: use backup-top instead of write notifiers", 2019-10-01), drop it to simplify the code. While at it, drop redundant assertions on flags. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1578495356-46219-2-git-send-email-pbonzini@redhat.com Message-Id: <1578495356-46219-2-git-send-email-pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-11-04block: Add bdrv_co_get_self_request()Max Reitz1-0/+18
Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191101152510.11719-3-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-04block: Make wait/mark serialising requests publicMax Reitz1-12/+12
Make both bdrv_mark_request_serialising() and bdrv_wait_serialising_requests() public so they can be used from block drivers. Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191101152510.11719-2-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-10-28' ↵Peter Maydell1-12/+17
into staging Block patches for softfreeze: - iotest patches - Improve performance of the mirror block job in write-blocking mode - Limit memory usage for the backup block job - Add discard and write-zeroes support to the NVMe host block driver - Fix a bug in the mirror job - Prevent the qcow2 driver from creating technically non-compliant qcow2 v3 images (where there is not enough extra data for snapshot table entries) - Allow callers of bdrv_truncate() (etc.) to determine whether the file must be resized to the exact given size or whether it is OK for block devices not to shrink # gpg: Signature made Mon 28 Oct 2019 12:13:53 GMT # gpg: using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40 # gpg: issuer "mreitz@redhat.com" # gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full] # Primary key fingerprint: 91BE B60A 30DB 3E88 57D1 1829 F407 DB00 61D5 CF40 * remotes/maxreitz/tags/pull-block-2019-10-28: (69 commits) qemu-iotests: restrict 264 to qcow2 only Revert "qemu-img: Check post-truncation size" block: Pass truncate exact=true where reasonable block: Let format drivers pass @exact block: Evaluate @exact in protocol drivers block: Add @exact parameter to bdrv_co_truncate() block: Do not truncate file node when formatting block/cor: Drop cor_co_truncate() block: Handle filter truncation like native impl. iotests: Test qcow2's snapshot table handling iotests: Add peek_file* functions qcow2: Fix v3 snapshot table entry compliancy qcow2: Repair snapshot table with too many entries qcow2: Fix overly long snapshot tables qcow2: Keep track of the snapshot table length qcow2: Fix broken snapshot table entries qcow2: Add qcow2_check_fix_snapshot_table() qcow2: Separate qcow2_check_read_snapshot_table() qcow2: Write v3-compliant snapshot list on upgrade qcow2: Put qcow2_upgrade() into its own function ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-28block: Add @exact parameter to bdrv_co_truncate()Max Reitz1-7/+13
We have two drivers (iscsi and file-posix) that (in some cases) return success from their .bdrv_co_truncate() implementation if the block device is larger than the requested offset, but cannot be shrunk. Some callers do not want that behavior, so this patch adds a new parameter that they can use to turn off that behavior. This patch just adds the parameter and lets the block/io.c and block/block-backend.c functions pass it around. All other callers always pass false and none of the implementations evaluate it, so that this patch does not change existing behavior. Future patches take care of that. Suggested-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-5-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block: Handle filter truncation like native impl.Max Reitz1-7/+6
Make the filter truncation (passing it through to bs->file) a first-class citizen and handle it exactly as if it was the filter driver's native implementation of .bdrv_co_truncate(). I do not see a reason not to, it makes the code a bit shorter, and may be even more correct because this gets us to finish the write_req that we prepared before (may be important to e.g. bring dirty bitmaps to the correct size). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-2-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-26core: replace getpagesize() with qemu_real_host_page_sizeWei Yang1-1/+1
There are three page size in qemu: real host page size host page size target page size All of them have dedicate variable to represent. For the last two, we use the same form in the whole qemu project, while for the first one we use two forms: qemu_real_host_page_size and getpagesize(). qemu_real_host_page_size is defined to be a replacement of getpagesize(), so let it serve the role. [Note] Not fully tested for some arch or device. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Message-Id: <20191013021145.16011-3-richardw.yang@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-14block: Reject misaligned write requests with BDRV_REQ_NO_FALLBACKAlberto Garcia1-0/+7
The BDRV_REQ_NO_FALLBACK flag means that an operation should only be performed if it can be offloaded or otherwise performed efficiently. However a misaligned write request requires a RMW so we should return an error and let the caller decide how to proceed. This hits an assertion since commit c8bb23cbdb if the required alignment is larger than the cluster size: qemu-img create -f qcow2 -o cluster_size=2k img.qcow2 4G qemu-io -c "open -o driver=qcow2,file.align=4k blkdebug::img.qcow2" \ -c 'write 0 512' qemu-io: block/io.c:1127: bdrv_driver_pwritev: Assertion `!(flags & BDRV_REQ_NO_FALLBACK)' failed. Aborted The reason is that when writing to an unallocated cluster we try to skip the copy-on-write part and zeroize it using BDRV_REQ_NO_FALLBACK instead, resulting in a write request that is too small (2KB cluster size vs 4KB required alignment). Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-10-14replay: add BH oneshot event for block layerPavel Dovgalyuk1-2/+2
Replay is capable of recording normal BH events, but sometimes there are single use callbacks scheduled with aio_bh_schedule_oneshot function. This patch enables recording and replaying such callbacks. Block layer uses these events for calling the completion function. Replaying these calls makes the execution deterministic. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Acked-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-10-14replay: don't drain/flush bdrv queue while RR is workingPavel Dovgalyuk1-0/+28
In record/replay mode bdrv queue is controlled by replay mechanism. It does not allow saving or loading the snapshots when bdrv queue is not empty. Stopping the VM is not blocked by nonempty queue, but flushing the queue is still impossible there, because it may cause deadlocks in replay mode. This patch disables bdrv_drain_all and bdrv_flush_all in record/replay mode. Stopping the machine when the IO requests are not finished is needed for the debugging. E.g., breakpoint may be set at the specified step, and forcing the IO requests to finish may break the determinism of the execution. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Acked-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-10-08block: Skip COR for inactive nodesMax Reitz1-14/+27
We must not write data to inactive nodes, and a COR is certainly something we can simply not do without upsetting anyone. So skip COR operations on inactive nodes. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20191001174827.11081-2-mreitz@redhat.com Message-Id: <20191001174827.11081-2-mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-09-16block: Use QEMU_IS_ALIGNEDNir Soffer1-4/+4
Replace instances of: (n & (BDRV_SECTOR_SIZE - 1)) == 0 And: (n & ~BDRV_SECTOR_MASK) == 0 With: QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE) Which reveals the intent of the code better, and makes it easier to locate the code checking alignment. Signed-off-by: Nir Soffer <nsoffer@redhat.com> Message-id: 20190827185913.27427-2-nsoffer@redhat.com Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-05block: workaround for unaligned byte range in fallocate()Andrey Shinkevich1-1/+1
Revert the commit 118f99442d 'block/io.c: fix for the allocation failure' and use better error handling for file systems that do not support fallocate() for an unaligned byte range. Allow falling back to pwrite in case fallocate() returns EINVAL. Suggested-by: Kevin Wolf <kwolf@redhat.com> Suggested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Message-Id: <1566913973-15490-1-git-send-email-andrey.shinkevich@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2019-08-27block/io: introduce bdrv_co_p{read, write}v_partVladimir Sementsov-Ogievskiy1-6/+23
Introduce extended variants of bdrv_co_preadv and bdrv_co_pwritev with qiov_offset parameter. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-10-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-10-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-27block/io: bdrv_aligned_pwritev: use and support qiov_offsetVladimir Sementsov-Ogievskiy1-14/+13
Use and support new API in bdrv_aligned_pwritev. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-9-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-9-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-27block/io: bdrv_aligned_preadv: use and support qiov_offsetVladimir Sementsov-Ogievskiy1-13/+8
Use and support new API in bdrv_co_do_copy_on_readv. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-8-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-8-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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