On Tue, Sep 08, 2015 at 11:28:31AM +0800, Wen Congyang wrote: > If we do copy-on-read in before_write_notifier, qemu will be crashed. The > backtrace is: > Program terminated with signal 6, Aborted. > #0 0x00007f5d69207b55 in raise () from /lib64/libc.so.6 > (gdb) bt > #0 0x00007f5d69207b55 in raise () from /lib64/libc.so.6 > #1 0x00007f5d69209131 in abort () from /lib64/libc.so.6 > #2 0x00007f5d69200a10 in __assert_fail () from /lib64/libc.so.6 > #3 0x00007f5d6cb3a0d5 in wait_serialising_requests (self=0x7f5d36feeae0) at > block/io.c:452 > #4 0x00007f5d6cb3ae79 in bdrv_aligned_preadv (bs=0x7f5d6d570170, > req=0x7f5d36feeae0, offset=93585408, bytes=65536, align=512, > qiov=0x7f5d36feec90, flags=1) > at block/io.c:847 > #5 0x00007f5d6cb3b3cc in bdrv_co_do_preadv (bs=0x7f5d6d570170, > offset=93585408, bytes=65536, qiov=0x7f5d36feec90, > flags=BDRV_REQ_COPY_ON_READ) > at block/io.c:971 > #6 0x00007f5d6cb3b497 in bdrv_co_do_readv (bs=0x7f5d6d570170, > sector_num=182784, nb_sectors=128, qiov=0x7f5d36feec90, flags=0) at > block/io.c:993 > #7 0x00007f5d6cb3b504 in bdrv_co_readv (bs=0x7f5d6d570170, > sector_num=182784, nb_sectors=128, qiov=0x7f5d36feec90) at block/io.c:1002 > #8 0x00007f5d6c8eaf42 in backup_do_cow (bs=0x7f5d6d570170, > sector_num=182784, nb_sectors=8, error_is_read=0x0) at block/backup.c:132 > #9 0x00007f5d6c8eb6cf in backup_before_write_notify > (notifier=0x7f5d435fcf30, opaque=0x7f5d36feee40) at block/backup.c:193 > #10 0x00007f5d6cb9ec33 in notifier_with_return_list_notify > (list=0x7f5d6d5731f8, data=0x7f5d36feee40) at util/notify.c:65 > #11 0x00007f5d6cb3bcc8 in bdrv_aligned_pwritev (bs=0x7f5d6d570170, > req=0x7f5d36feee40, offset=93585408, bytes=4096, qiov=0x7f5d6eef4cf8, flags=0) > at block/io.c:1126 > #12 0x00007f5d6cb3c79e in bdrv_co_do_pwritev (bs=0x7f5d6d570170, > offset=93585408, bytes=4096, qiov=0x7f5d6eef4cf8, flags=0) at block/io.c:1364 > #13 0x00007f5d6cb3c867 in bdrv_co_do_writev (bs=0x7f5d6d570170, > sector_num=182784, nb_sectors=8, qiov=0x7f5d6eef4cf8, flags=0) at > block/io.c:1388 > #14 0x00007f5d6cb3ea09 in bdrv_co_do_rw (opaque=0x7f5d38465ee0) at > block/io.c:2123 > #15 0x00007f5d6caeb03d in coroutine_trampoline (i0=944146112, i1=32605) at > coroutine-ucontext.c:80 > #16 0x00007f5d69218be0 in __correctly_grouped_prefixwc () from > /lib64/libc.so.6 > #17 0x0000000000000000 in ?? () > > > Wen Congyang (2): > block: Introduce a new API bdrv_co_no_copy_on_readv() > Backup: don't do copy-on-read in before_write_notifier > > block/backup.c | 20 ++++++++++++++------ > block/io.c | 12 +++++++++++- > include/block/block.h | 9 ++++++--- > trace-events | 1 + > 4 files changed, 32 insertions(+), 10 deletions(-) > > -- > 2.4.3 >
Thanks, applied to my block branch: git://github.com/codyprime/qemu-kvm-jtc.git block -Jeff
