Hi,
Replying to myself again. :)
I see this problem only if I attempt to use a zpool that already exists.
If I create one (using files instead of devices, don't know if it
matters) like ztest does, it works like a charm.
Any clue as to why this is so would be appreciated.
Cheers
Manoj
Manoj Joseph wrote:
> Hi,
>
> I tried adding an spa_export();spa_import() to the code snippet. I get a
> similar crash while importing.
>
> I/O failure (write on <unknown> off 0: zio 822ed40 [L0 unallocated]
> 4000L/400P DVA[0]=<0:1000:400> DVA[1]=<0:18001000:400> fletcher4 lzjb LE
> contiguous birth=4116 fill=0
> cksum=69c3a4acfc:2c42fdcaced5:c5231ffcb2285:2b8c1a5f2cb2bfd): error 28
> Abort (core dumped)
>
> I thought ztest could use an existing pool. Is that assumption wrong?
>
> These are the stacks of interest.
>
> d11d78b9 __lwp_park (81c3e0c, 81c3d70, 0) + 19
> d11d1ad2 cond_wait_queue (81c3e0c, 81c3d70, 0, 0) + 3e
> d11d1fbd _cond_wait (81c3e0c, 81c3d70) + 69
> d11d1ffb cond_wait (81c3e0c, 81c3d70) + 24
> d131e4d2 cv_wait (81c3e0c, 81c3d6c) + 5e
> d12fe2dd txg_wait_synced (81c3cc0, 1014, 0) + 179
> d12f9080 spa_config_update (819dac0, 0) + c4
> d12f467a spa_import (8047657, 8181f88, 0) + 256
> 080510c6 main (2, 804749c, 80474a8) + b2
> 08050f22 _start (2, 8047650, 8047657, 0, 804765c, 8047678) + 7a
>
>
> d131ed79 vpanic (d1341dbc, ca5cd248) + 51
> d131ed9f panic (d1341dbc, d135a384, d135a724, d133a630, 0, 0) + 1f
> d131921d zio_done (822ed40) + 455
> d131c15d zio_next_stage (822ed40) + 161
> d1318b92 zio_wait_for_children (822ed40, 11, 822ef30) + 6a
> d1318c88 zio_wait_children_done (822ed40) + 18
> d131c15d zio_next_stage (822ed40) + 161
> d131ba83 zio_vdev_io_assess (822ed40) + 183
> d131c15d zio_next_stage (822ed40) + 161
> d1307011 vdev_mirror_io_done (822ed40) + 421
> d131b8a2 zio_vdev_io_done (822ed40) + 36
> d131c15d zio_next_stage (822ed40) + 161
> d1318b92 zio_wait_for_children (822ed40, 11, 822ef30) + 6a
> d1318c88 zio_wait_children_done (822ed40) + 18
> d1306be6 vdev_mirror_io_start (822ed40) + 1d2
> d131b862 zio_vdev_io_start (822ed40) + 34e
> d131c313 zio_next_stage_async (822ed40) + 1ab
> d131bb47 zio_vdev_io_assess (822ed40) + 247
> d131c15d zio_next_stage (822ed40) + 161
> d1307011 vdev_mirror_io_done (822ed40) + 421
> d131b8a2 zio_vdev_io_done (822ed40) + 36
> d131c15d zio_next_stage (822ed40) + 161
> d1318b92 zio_wait_for_children (822ed40, 11, 822ef30) + 6a
> d1318c88 zio_wait_children_done (822ed40) + 18
> d1306be6 vdev_mirror_io_start (822ed40) + 1d2
> d131b862 zio_vdev_io_start (822ed40) + 34e
> d131c15d zio_next_stage (822ed40) + 161
> d1318dc1 zio_ready (822ed40) + 131
> d131c15d zio_next_stage (822ed40) + 161
> d131b41b zio_dva_allocate (822ed40) + 343
> d131c15d zio_next_stage (822ed40) + 161
> d131bdcb zio_checksum_generate (822ed40) + 123
> d131c15d zio_next_stage (822ed40) + 161
> d1319873 zio_write_compress (822ed40) + 4af
> d131c15d zio_next_stage (822ed40) + 161
> d1318b92 zio_wait_for_children (822ed40, 1, 822ef28) + 6a
> d1318c68 zio_wait_children_ready (822ed40) + 18
> d131c313 zio_next_stage_async (822ed40) + 1ab
> d1318b1f zio_nowait (822ed40) + 1b
> d12c6941 arc_write (82490c0, 819dac0, 7, 3, 2, 1014) + 1ed
> d12ce7ae dbuf_sync (82bd008, 82490c0, 82beb40) + e6e
> d12e2ecb dnode_sync (82ea090, 0, 82490c0, 82beb40) + 517
> d12d663a dmu_objset_sync_dnodes (82a6e00, 82a6ee4, 82beb40) + 14e
> d12d6983 dmu_objset_sync (82a6e00, 82beb40) + 137
> d12ec20e dsl_pool_sync (81c3cc0, 1014, 0) + 182
> d12f7db6 spa_sync (819dac0, 1014, 0) + 26e
> d12fdf14 txg_sync_thread (81c3cc0) + 2a8
> d11d7604 _thr_setup (ccdda400) + 52
> d11d7860 _lwp_start (ccdda400, 0, 0, 0, 0, 0)
>
> Regards,
> Manoj
>
> Manoj Joseph wrote:
>> Hi,
>>
>> Trying to understand the zfs code, I was playing with libzpool - like
>> ztest does.
>>
>> What I am trying to do is create an object in a zfs filesystem. But I
>> am seeing failures when I try to sync changes.
>>
>> bash-3.00# ./udmu test Object 4 error: ZFS: I/O failure (write on
>> <unknown> off 0: zio 81f5d00 [L0 unallocated] 200L/200P
>> DVA[0]=<0:0:200> fletcher2 uncompressed LE contiguous birth=7 fill=0
>> cksum=4141414141414141:4141:2828282828282820:82820): error 28
>> Abort (core dumped)
>>
>> I can see that space does not get allocated and sync results in
>> ENOSPC. There is plenty of space in the pool. So, that is not the
>> issue. I guess I am missing the step of allocating space. Could
>> someone help me figure out what it is?
>>
>> I have tried to follow what ztest does. This is what I do:
>>
>> <code snippet>
>> kernel_init(FREAD | FWRITE);
>> buf = malloc(BUF_SIZE);
>> memset(buf, 'A', BUF_SIZE);
>>
>> error = dmu_objset_open(osname, DMU_OST_ZFS, DS_MODE_PRIMARY, &os);
>> if (error) {
>> fprintf(stderr, "dmu_objset_open() = %d", error);
>> return (error);
>> }
>> tx = dmu_tx_create(os);
>> dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, BUF_SIZE);
>> // dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
>>
>> error = dmu_tx_assign(tx, TXG_WAIT);
>> if (error) {
>> dmu_tx_abort(tx);
>> return (error);
>> }
>>
>> object = dmu_object_alloc(os, DMU_OT_UINT64_OTHER, 0,
>> DMU_OT_NONE, 0, tx);
>>
>> printf("Object %lld\n", object);
>>
>> dmu_write(os, object, 0, BUF_SIZE, buf, tx);
>> dmu_tx_commit(tx);
>>
>> txg_wait_synced(dmu_objset_pool(os), 0);
>> </code snippet>
>>
>> It is interesting that the checksum that is reported is the pattern
>> that I try to write.
>>
>> This is the panic stack:
>> d11d8e65 _lwp_kill (98, 6) + 15
>> d1192102 raise (6) + 22
>> d1170dad abort (81f5d00, d1354000, ce3fdcc8, ce3fdcbc, d13c0568,
>> ce3fdcbc) + cd
>> d131ed79 vpanic (d1341dbc, ce3fdcc8) + 51
>> d131ed9f panic (d1341dbc, d135a384, d135a724, d133a630, 0, 0) + 1f
>> d131921d zio_done (81f5d00) + 455
>> d131c15d zio_next_stage (81f5d00) + 161
>> d1318b92 zio_wait_for_children (81f5d00, 11, 81f5ef0) + 6a
>> d1318c88 zio_wait_children_done (81f5d00) + 18
>> d131c15d zio_next_stage (81f5d00) + 161
>> d131ba83 zio_vdev_io_assess (81f5d00) + 183
>> d131c15d zio_next_stage (81f5d00) + 161
>> d1307011 vdev_mirror_io_done (81f5d00) + 421
>> d131b8a2 zio_vdev_io_done (81f5d00, 0, d0e0ac00, d1210000, d11ba2df,
>> 3) + 36
>> d131f585 taskq_thread (81809c0) + 89
>> d11d7604 _thr_setup (d0e0ac00) + 52
>> d11d7860 _lwp_start (d0e0ac00, 0, 0, 0, 0, 0)
>>
>> Thanks in advance!
>>
>> Regards,
>> Manoj
