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2021-11-02block-backend: Silence clang -m32 compiler warningHanna Reitz
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>
2021-10-15block-backend: drop INT_MAX restriction from blk_check_byte_request()Vladimir Sementsov-Ogievskiy
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-Ogievskiy
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-Ogievskiy
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-Ogievskiy
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-Ogievskiy
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-Ogievskiy
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-backend: rename _do_ helper functions to _co_do_Vladimir Sementsov-Ogievskiy
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-Ogievskiy
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-Ogievskiy
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-Ogievskiy
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-Ogievskiy
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>
2021-10-06block: introduce max_hw_iov for use in scsi-genericPaolo Bonzini
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>
2021-09-01block: introduce blk_replace_bsVladimir Sementsov-Ogievskiy
Add function to change bs inside blk. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-3-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-06-25block: add max_hw_transfer to BlockLimitsPaolo Bonzini
For block host devices, I/O can happen through either the kernel file descriptor I/O system calls (preadv/pwritev, io_submit, io_uring) or the SCSI passthrough ioctl SG_IO. In the latter case, the size of each transfer can be limited by the HBA, while for file descriptor I/O the kernel is able to split and merge I/O in smaller pieces as needed. Applying the HBA limits to file descriptor I/O results in more system calls and suboptimal performance, so this patch splits the max_transfer limit in two: max_transfer remains valid and is used in general, while max_hw_transfer is limited to the maximum hardware size. max_hw_transfer can then be included by the scsi-generic driver in the block limits page, to ensure that the stricter hardware limit is used. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-25block-backend: align max_transfer to request alignmentPaolo Bonzini
Block device requests must be aligned to bs->bl.request_alignment. It makes sense for drivers to align bs->bl.max_transfer the same way; however when there is no specified limit, blk_get_max_transfer just returns INT_MAX. Since the contract of the function does not specify that INT_MAX means "no maximum", just align the outcome of the function (whether INT_MAX or bs->bl.max_transfer) before returning it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-02block-backend: add drained_pollSergio Lopez
Allow block backends to poll their devices/users to check if they have been quiesced when entering a drained section. This will be used in the next patch to wait for the NBD server to be completely quiesced. Suggested-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Sergio Lopez <slp@redhat.com> Message-Id: <20210602060552.17433-2-slp@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block-backend: improve blk_root_get_parent_desc()Vladimir Sementsov-Ogievskiy
We have different types of parents: block nodes, block backends and jobs. So, it makes sense to specify type together with name. While being here also use g_autofree. iotest 307 output is updated. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20210601075218.79249-3-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block: drop BlockBackendRootState::read_onlyVladimir Sementsov-Ogievskiy
Instead of keeping additional boolean field, let's store the information in BDRV_O_RDWR bit of BlockBackendRootState::open_flags. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210527154056.70294-4-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block: consistently use bdrv_is_read_only()Vladimir Sementsov-Ogievskiy
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>
2021-05-02Do not include sysemu/sysemu.h if it's not really necessaryThomas Huth
Stop including sysemu/sysemu.h in files that don't need it. Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20210416171314.2074665-2-thuth@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-04-30block: Add BDRV_O_NO_SHARE for blk_new_open()Kevin Wolf
Normally, blk_new_open() just shares all permissions. This was fine originally when permissions only protected against uses in the same process because no other part of the code would actually get to access the block nodes opened with blk_new_open(). However, since we use it for file locking now, unsharing permissions becomes desirable. Add a new BDRV_O_NO_SHARE flag that is used in blk_new_open() to unshare any permissions that can be unshared. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210422164344.283389-2-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>
2021-04-30block: drop ctx argument from bdrv_root_attach_childVladimir Sementsov-Ogievskiy
Passing parent aio context is redundant, as child_class and parent opaque pointer are enough to retrieve it. Drop the argument and use new bdrv_child_get_parent_aio_context() interface. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-7-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: BdrvChildClass: add .get_parent_aio_context handlerVladimir Sementsov-Ogievskiy
Add new handler to get aio context and implement it in all child classes. Add corresponding public interface to be used soon. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-6-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-03-09sysemu: Let VMChangeStateHandler take boolean 'running' argumentPhilippe Mathieu-Daudé
The 'running' argument from VMChangeStateHandler does not require other value than 0 / 1. Make it a plain boolean. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: David Gibson <david@gibson.dropbear.id.au> Message-Id: <20210111152020.1422021-3-philmd@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-01-27block: Separate blk_is_writable() and blk_supports_write_perm()Kevin Wolf
Currently, blk_is_read_only() tells whether a given BlockBackend can only be used in read-only mode because its root node is read-only. Some callers actually try to answer a slightly different question: Is the BlockBackend configured to be writable, by taking write permissions on the root node? This can differ, for example, for CD-ROM devices which don't take write permissions, but may be backed by a writable image file. scsi-cd allows write requests to the drive if blk_is_read_only() returns false. However, the write request will immediately run into an assertion failure because the write permission is missing. This patch introduces separate functions for both questions. blk_supports_write_perm() answers the question whether the block node/image file can support writable devices, whereas blk_is_writable() tells whether the BlockBackend is currently configured to be writable. All calls of blk_is_read_only() are converted to one of the two new functions. Fixes: https://bugs.launchpad.net/bugs/1906693 Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210118123448.307825-2-kwolf@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-23qemu/atomic.h: rename atomic_ to qatomic_Stefan Hajnoczi
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>
2020-09-07commit: Deal with filtersMax Reitz
This includes some permission limiting (for example, we only need to take the RESIZE permission if the base is smaller than the top). Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-21block: fix bdrv_aio_cancel() for ENOMEDIUM requestsStefan Hajnoczi
bdrv_aio_cancel() calls aio_poll() on the AioContext for the given I/O request until it has completed. ENOMEDIUM requests are special because there is no BlockDriverState when the drive has no medium! Define a .get_aio_context() function for BlkAioEmAIOCB requests so that bdrv_aio_cancel() can find the AioContext where the completion BH is pending. Without this function bdrv_aio_cancel() aborts on ENOMEDIUM requests! libFuzzer triggered the following assertion: cat << EOF | qemu-system-i386 -M pc-q35-5.0 \ -nographic -monitor none -serial none \ -qtest stdio -trace ide\* outl 0xcf8 0x8000fa24 outl 0xcfc 0xe106c000 outl 0xcf8 0x8000fa04 outw 0xcfc 0x7 outl 0xcf8 0x8000fb20 write 0x0 0x3 0x2780e7 write 0xe106c22c 0xd 0x1130c218021130c218021130c2 write 0xe106c218 0x15 0x110010110010110010110010110010110010110010 EOF ide_exec_cmd IDE exec cmd: bus 0x56170a77a2b8; state 0x56170a77a340; cmd 0xe7 ide_reset IDEstate 0x56170a77a340 Aborted (core dumped) (gdb) bt #1 0x00007ffff4f93895 in abort () at /lib64/libc.so.6 #2 0x0000555555dc6c00 in bdrv_aio_cancel (acb=0x555556765550) at block/io.c:2745 #3 0x0000555555dac202 in blk_aio_cancel (acb=0x555556765550) at block/block-backend.c:1546 #4 0x0000555555b1bd74 in ide_reset (s=0x555557213340) at hw/ide/core.c:1318 #5 0x0000555555b1e3a1 in ide_bus_reset (bus=0x5555572132b8) at hw/ide/core.c:2422 #6 0x0000555555b2aa27 in ahci_reset_port (s=0x55555720eb50, port=2) at hw/ide/ahci.c:650 #7 0x0000555555b29fd7 in ahci_port_write (s=0x55555720eb50, port=2, offset=44, val=16) at hw/ide/ahci.c:360 #8 0x0000555555b2a564 in ahci_mem_write (opaque=0x55555720eb50, addr=556, val=16, size=1) at hw/ide/ahci.c:513 #9 0x000055555598415b in memory_region_write_accessor (mr=0x55555720eb80, addr=556, value=0x7fffffffb838, size=1, shift=0, mask=255, attrs=...) at softmmu/memory.c:483 Looking at bdrv_aio_cancel: 2728 /* async I/Os */ 2729 2730 void bdrv_aio_cancel(BlockAIOCB *acb) 2731 { 2732 qemu_aio_ref(acb); 2733 bdrv_aio_cancel_async(acb); 2734 while (acb->refcnt > 1) { 2735 if (acb->aiocb_info->get_aio_context) { 2736 aio_poll(acb->aiocb_info->get_aio_context(acb), true); 2737 } else if (acb->bs) { 2738 /* qemu_aio_ref and qemu_aio_unref are not thread-safe, so 2739 * assert that we're not using an I/O thread. Thread-safe 2740 * code should use bdrv_aio_cancel_async exclusively. 2741 */ 2742 assert(bdrv_get_aio_context(acb->bs) == qemu_get_aio_context()); 2743 aio_poll(bdrv_get_aio_context(acb->bs), true); 2744 } else { 2745 abort(); <=============== 2746 } 2747 } 2748 qemu_aio_unref(acb); 2749 } Fixes: 02c50efe08736116048d5fc355043080f4d5859c ("block: Add bdrv_aio_cancel_async") Reported-by: Alexander Bulekov <alxndr@bu.edu> Buglink: https://bugs.launchpad.net/qemu/+bug/1878255 Originally-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200720100141.129739-1-stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-14block: Avoid stale pointer dereference in blk_get_aio_context()Greg Kurz
It is possible for blk_remove_bs() to race with blk_drain_all(), causing the latter to dereference a stale blk->root pointer: blk_remove_bs(blk) bdrv_root_unref_child(blk->root) child_bs = blk->root->bs bdrv_detach_child(blk->root) ... g_free(blk->root) <============== blk->root becomes stale bdrv_unref(child_bs) <============ yield at some point A blk_drain_all() can be triggered by some guest action in the meantime, eg. on POWER, SLOF might disable bus mastering on a virtio-scsi-pci device: virtio_write_config() virtio_pci_stop_ioeventfd() virtio_bus_stop_ioeventfd() virtio_scsi_dataplane_stop() blk_drain_all() blk_get_aio_context() bs = blk->root ? blk->root->bs : NULL ^^^^^^^^^ stale Then, depending on one's luck, QEMU either crashes with SEGV or hits the assertion in blk_get_aio_context(). blk->root is set by blk_insert_bs() which calls bdrv_root_attach_child() first. The blk_remove_bs() function should rollback the changes made by blk_insert_bs() in the opposite order (or it should be documented somewhere why this isn't the case). Clear blk->root before calling bdrv_root_unref_child() in blk_remove_bs(). Signed-off-by: Greg Kurz <groug@kaod.org> Message-Id: <159430264541.389456.11925072456012783045.stgit@bahia.lan> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass BdrvChildRole in remaining casesMax Reitz
These calls have no real use for the child role yet, but it will not harm to give one. Notably, the bdrv_root_attach_child() call in blockjob.c is left unmodified because there is not much the generic BlockJob object wants from its children. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-34-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass parent_is_format to .inherit_options()Max Reitz
We plan to unify the generic .inherit_options() functions. The resulting common function will need to decide whether to force-enable format probing, force-disable it, or leave it as-is. To make this decision, it will need to know whether the parent node is a format node or not (because we never want format probing if the parent is a format node already (except for the backing chain)). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-9-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass BdrvChildRole to .inherit_options()Max Reitz
For now, all callers (effectively) pass 0 and no callee evaluates thie value. Later patches will change both. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-8-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add BdrvChildRole to BdrvChildMax Reitz
For now, it is always set to 0. Later patches in this series will ensure that all callers pass an appropriate combination of flags. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-6-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Rename BdrvChildRole to BdrvChildClassMax Reitz
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>
2020-05-18block: Add blk_make_empty()Max Reitz
Two callers of BlockDriver.bdrv_make_empty() remain that should not call this method directly. Both do not have access to a BdrvChild, but they can use a BlockBackend, so we add this function that lets them use it. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200429141126.85159-4-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-05block: Add blk_new_with_bs() helperEric Blake
There are several callers that need to create a new block backend from an existing BDS; make the task slightly easier with a common helper routine. Suggested-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200424190903.522087-2-eblake@redhat.com> [mreitz: Set @ret only in error paths, see https://lists.nongnu.org/archive/html/qemu-block/2020-04/msg01216.html] Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200428192648.749066-2-eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-04-30block-backend: Add flags to blk_truncate()Kevin Wolf
Now that node level interface bdrv_truncate() supports passing request flags to the block driver, expose this on the BlockBackend level, too. 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: <20200424125448.63318-4-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30block: Add flags to bdrv(_co)_truncate()Kevin Wolf
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>
2020-04-07block: Fix blk->in_flight during blk_wait_while_drained()Kevin Wolf
Waiting in blk_wait_while_drained() while blk->in_flight is increased for the current request is wrong because it will cause the drain operation to deadlock. This patch makes sure that blk_wait_while_drained() is called with blk->in_flight increased exactly once for the current request, and that it temporarily decreases the counter while it waits. Fixes: cf3129323f900ef5ddbccbe86e4fa801e88c566e Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200407121259.21350-4-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-07block: Increase BB.in_flight for coroutine and sync interfacesKevin Wolf
External callers of blk_co_*() and of the synchronous blk_*() functions don't currently increase the BlockBackend.in_flight counter, but calls from blk_aio_*() do, so there is an inconsistency whether the counter has been increased or not. This patch moves the actual operations to static functions that can later know they will always be called with in_flight increased exactly once, even for external callers using the blk_co_*() coroutine interfaces. If the public blk_co_*() interface is unused, remove it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200407121259.21350-3-kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-07block-backend: Reorder flush/pdiscard function definitionsKevin Wolf
Move all variants of the flush/pdiscard functions to a single place and put the blk_co_*() version first because it is called by all other variants (and will become static in the next patch). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200407121259.21350-2-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-10-28block: Add @exact parameter to bdrv_co_truncate()Max Reitz
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/block-backend: add blk_co_pwritev_partVladimir Sementsov-Ogievskiy
Add blk write function with qiov_offset parameter. It's needed for the following commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20191011090711.19940-4-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-14replay: add BH oneshot event for block layerPavel Dovgalyuk
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>
2019-08-16Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into stagingPeter Maydell
Block layer patches: - file-posix: Fix O_DIRECT alignment detection - Fixes for concurrent block jobs - block-backend: Queue requests while drained (fix IDE vs. job crashes) - qemu-img convert: Deprecate using -n and -o together - iotests: Migration tests with filter nodes - iotests: More media change tests # gpg: Signature made Fri 16 Aug 2019 10:29:18 BST # gpg: using RSA key 7F09B272C88F2FD6 # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full] # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * remotes/kevin/tags/for-upstream: file-posix: Handle undetectable alignment qemu-img convert: Deprecate using -n and -o together block-backend: Queue requests while drained mirror: Keep mirror_top_bs drained after dropping permissions block: Remove blk_pread_unthrottled() iotests: Add test for concurrent stream/commit tests: Test mid-drain bdrv_replace_child_noperm() tests: Test polling in bdrv_drop_intermediate() block: Reduce (un)drains when replacing a child block: Keep subtree drained in drop_intermediate block: Simplify bdrv_filter_default_perms() iotests: Test migration with all kinds of filter nodes iotests: Move migration helpers to iotests.py iotests/118: Add -blockdev based tests iotests/118: Create test classes dynamically iotests/118: Test media change for scsi-cd Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16sysemu: Split sysemu/runstate.h off sysemu/sysemu.hMarkus Armbruster
sysemu/sysemu.h is a rather unfocused dumping ground for stuff related to the system-emulator. Evidence: * It's included widely: in my "build everything" tree, changing sysemu/sysemu.h still triggers a recompile of some 1100 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h, down from 5400 due to the previous two commits). * It pulls in more than a dozen additional headers. Split stuff related to run state management into its own header sysemu/runstate.h. Touching sysemu/sysemu.h now recompiles some 850 objects. qemu/uuid.h also drops from 1100 to 850, and qapi/qapi-types-run-state.h from 4400 to 4200. Touching new sysemu/runstate.h recompiles some 500 objects. Since I'm touching MAINTAINERS to add sysemu/runstate.h anyway, also add qemu/main-loop.h. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190812052359.30071-30-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> [Unbreak OS-X build]
2019-08-16Include qemu/main-loop.h lessMarkus Armbruster
In my "build everything" tree, changing qemu/main-loop.h triggers a recompile of some 5600 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). It includes block/aio.h, which in turn includes qemu/event_notifier.h, qemu/notify.h, qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h, qemu/thread.h, qemu/timer.h, and a few more. Include qemu/main-loop.h only where it's needed. Touching it now recompiles only some 1700 objects. For block/aio.h and qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the others, they shrink only slightly. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190812052359.30071-21-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16trace: Do not include qom/cpu.h into generated trace.hMarkus Armbruster
docs/devel/tracing.txt explains "since many source files include trace.h, [the generated trace.h use] a minimum of types and other header files included to keep the namespace clean and compile times and dependencies down." Commit 4815185902 "trace: Add per-vCPU tracing states for events with the 'vcpu' property" made them all include qom/cpu.h via control-internal.h. qom/cpu.h in turn includes about thirty headers. Ouch. Per-vCPU tracing is currently not supported in sub-directories' trace-events. In other words, qom/cpu.h can only be used in trace-root.h, not in any trace.h. Split trace/control-vcpu.h off trace/control.h and trace/control-internal.h. Have the generated trace.h include trace/control.h (which no longer includes qom/cpu.h), and trace-root.h include trace/control-vcpu.h (which includes it). The resulting improvement is a bit disappointing: in my "build everything" tree, some 1100 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h) depend on a trace.h, and about 600 of them no longer depend on qom/cpu.h. But more than 1300 others depend on trace-root.h. More work is clearly needed. Left for another day. Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20190812052359.30071-8-armbru@redhat.com>
2019-08-16block-backend: Queue requests while drainedKevin Wolf
This fixes devices like IDE that can still start new requests from I/O handlers in the CPU thread while the block backend is drained. The basic assumption is that in a drain section, no new requests should be allowed through a BlockBackend (blk_drained_begin/end don't exist, we get drain sections only on the node level). However, there are two special cases where requests should not be queued: 1. Block jobs: We already make sure that block jobs are paused in a drain section, so they won't start new requests. However, if the drain_begin is called on the job's BlockBackend first, it can happen that we deadlock because the job stays busy until it reaches a pause point - which it can't if its requests aren't processed any more. The proper solution here would be to make all requests through the job's filter node instead of using a BlockBackend. For now, just disabling request queuing on the job BlockBackend is simpler. 2. In test cases where making requests through bdrv_* would be cumbersome because we'd need a BdrvChild. As we already got the functionality to disable request queuing from 1., use it in tests, too, for convenience. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>