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195332c1d9
vduse_blk_detach_ctx() waits for in-flight requests using AIO_WAIT_WHILE(). This is not allowed according to a comment in bdrv_set_aio_context_commit(): /* * Take the old AioContex when detaching it from bs. * At this point, new_context lock is already acquired, and we are now * also taking old_context. This is safe as long as bdrv_detach_aio_context * does not call AIO_POLL_WHILE(). */ Use this opportunity to rewrite the drain code in vduse-blk: - Use the BlockExport refcount so that vduse_blk_exp_delete() is only called when there are no more requests in flight. - Implement .drained_poll() so in-flight request coroutines are stopped by the time .bdrv_detach_aio_context() is called. - Remove AIO_WAIT_WHILE() from vduse_blk_detach_ctx() to solve the .bdrv_detach_aio_context() constraint violation. It's no longer needed due to the previous changes. - Always handle the VDUSE file descriptor, even in drained sections. The VDUSE file descriptor doesn't submit I/O, so it's safe to handle it in drained sections. This ensures that the VDUSE kernel code gets a fast response. - Suspend virtqueue fd handlers in .drained_begin() and resume them in .drained_end(). This eliminates the need for the aio_set_fd_handler(is_external=true) flag, which is being removed from QEMU. This is a long list but splitting it into individual commits would probably lead to git bisect failures - the changes are all related. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230516190238.8401-14-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
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| .. | ||
| export.c | ||
| fuse.c | ||
| meson.build | ||
| vduse-blk.c | ||
| vduse-blk.h | ||
| vhost-user-blk-server.c | ||
| vhost-user-blk-server.h | ||
| virtio-blk-handler.c | ||
| virtio-blk-handler.h | ||