From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39323) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X442I-00071Q-Q0 for qemu-devel@nongnu.org; Mon, 07 Jul 2014 04:12:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X442B-00075b-9e for qemu-devel@nongnu.org; Mon, 07 Jul 2014 04:12:30 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:6705) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X442A-00072I-IE for qemu-devel@nongnu.org; Mon, 07 Jul 2014 04:12:23 -0400 Message-ID: <53BA5653.4020101@huawei.com> Date: Mon, 7 Jul 2014 16:12:03 +0800 From: ChenLiang MIME-Version: 1.0 References: <1404291017-7456-1-git-send-email-arei.gonglei@huawei.com> <53B3CB04.5040909@redhat.com> <53B3CFB8.5000800@huawei.com> <53B3D011.9000200@redhat.com> <33183CC9F5247A488A2544077AF1902086C18093@SZXEMA503-MBS.china.huawei.com> <53B3DBFD.1090009@redhat.com> <53B3EDFF.6010309@huawei.com> <53B3EF92.2020406@redhat.com> <53B3F3A6.1060707@huawei.com> <53B3F8EB.1010008@redhat.com> <53B4BEA3.7020506@huawei.com> <53B53364.9090208@redhat.com> In-Reply-To: <53B53364.9090208@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] ide: fix double free List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: "kwolf@redhat.com" , "Gonglei (Arei)" , "Huangweidong (C)" , "qemu-devel@nongnu.org" , "stefanha@redhat.com" On 2014/7/3 18:41, Paolo Bonzini wrote: > Il 03/07/2014 04:23, ChenLiang ha scritto: >> Program received signal SIGABRT, Aborted. >> 0x00007fd548355b55 in raise () from /lib64/libc.so.6 >> (gdb) bt >> #0 0x00007fd548355b55 in raise () from /lib64/libc.so.6 >> #1 0x00007fd548357131 in abort () from /lib64/libc.so.6 >> #2 0x00007fd548393e0f in __libc_message () from /lib64/libc.so.6 >> #3 0x00007fd548399618 in malloc_printerr () from /lib64/libc.so.6 >> #4 0x00007fd54b15e80e in free_and_trace (mem=0x7fd54beb2230) at vl.c:2815 >> #5 0x00007fd54b3453cd in qemu_aio_release (p=0x7fd54beb2230) at block.c:4813 >> #6 0x00007fd54b15717d in dma_complete (dbs=0x7fd54beb2230, ret=0) at dma-helpers.c:132 >> #7 0x00007fd54b157253 in dma_bdrv_cb (opaque=0x7fd54beb2230, ret=0) at dma-helpers.c:148 >> #8 0x00007fd54b344db8 in bdrv_co_em_bh (opaque=0x7fd54bea4b30) at block.c:4676 >> #9 0x00007fd54b335a72 in aio_bh_poll (ctx=0x7fd54bcec990) at async.c:81 >> #10 0x00007fd54b34b1b4 in aio_poll (ctx=0x7fd54bcec990, blocking=false) at aio-posix.c:188 >> #11 0x00007fd54b335ee0 in aio_ctx_dispatch (source=0x7fd54bcec990, callback=0x0, user_data=0x0) at async.c:211 >> #12 0x00007fd549e3669a in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0 >> #13 0x00007fd54b348c45 in glib_pollfds_poll () at main-loop.c:190 >> #14 0x00007fd54b348d3d in os_host_main_loop_wait (timeout=0) at main-loop.c:235 >> #15 0x00007fd54b348e2f in main_loop_wait (nonblocking=0) at main-loop.c:484 >> #16 0x00007fd54b15b0f8 in main_loop () at vl.c:2007 >> #17 0x00007fd54b162a35 in main (argc=57, argv=0x7fff152720a8, envp=0x7fff15272278) at vl.c:4526 >> >> (gdb) bt >> #0 qemu_aio_release (p=0x7f86420ebec0) at block.c:4811 >> #1 0x00007f86412b617d in dma_complete (dbs=0x7f86420ebec0, ret=0) at dma-helpers.c:132 >> #2 0x00007f86412b65ab in dma_aio_cancel (acb=0x7f86420ebec0) at dma-helpers.c:192 >> #3 0x00007f86414a3996 in bdrv_aio_cancel (acb=0x7f86420ebec0) at block.c:4559 >> #4 0x00007f86413906af in ide_bus_reset (bus=0x7f8641fe3a20) at hw/ide/core.c:2056 >> #5 0x00007f86413967d6 in piix3_reset (opaque=0x7f8641fe32a0) at hw/ide/piix.c:114 >> #6 0x00007f86412b9a37 in qemu_devices_reset () at vl.c:1829 >> #7 0x00007f86412b9aef in qemu_system_reset (report=true) at vl.c:1842 >> #8 0x00007f86412b9fe2 in main_loop_should_exit () at vl.c:1971 >> #9 0x00007f86412ba100 in main_loop () at vl.c:2011 >> #10 0x00007f86412c1a35 in main (argc=57, argv=0x7fff2e827d38, envp=0x7fff2e827f08) at vl.c:4526 > > Ok, this is the same as your previous backtrace. The bug is still the same: dma_bdrv_cb must not be called dma_aio_cancel has finished the recursive call to bdrv_aio_cancel. > >> BTW, is it better to rename dbs->in_cancel to dbs->canceled ? > > If we were to apply my patch, yes. But with the current logic "in_cancel" says "are we inside the recursive call to bdrv_aio_cancel" so I think the answer is no. My patch is just a band-aid, I don't think it should be applied. > > Paolo > > . > Hi, virtio_blk_reset uses bdrv_drain_all too. static void virtio_blk_reset(VirtIODevice *vdev) { VirtIOBlock *s = VIRTIO_BLK(vdev); #ifdef CONFIG_VIRTIO_BLK_DATA_PLANE if (s->dataplane) { virtio_blk_data_plane_stop(s->dataplane); } #endif /* * This should cancel pending requests, but can't do nicely until there * are per-device request lists. */ bdrv_drain_all(); bdrv_set_enable_write_cache(s->bs, s->original_wce); } Best regards Chenliang