[LU-17255] dt_record_write()) ASSERTION( dt->do_body_ops->dbo_write )

• Status: Open
• Project: Lustre
• Type: Bug
• Priority: Minor
• Reporter: Sergey Cheremencev
• Assignee: WC Triage
• Resolution: Unresolved
• Severity: 3

Description

[15148.368109] LustreError: 11399:0:(dt_object.c:532:dt_record_write()) ASSERTION( dt->do_body_ops->dbo_write ) failed: [0x240000401:0x2:0x0]
[15148.368823] LustreError: 11399:0:(dt_object.c:532:dt_record_write()) LBUG
[15148.369203] Pid: 11399, comm: tgt_recover_1 3.10.0-1160.49.1.el7_lustre.x86_64 #1 SMP Fri Jun 17 18:46:08 UTC 2022
[15148.369204] Call Trace:
[15148.369218] [<0>] libcfs_call_trace+0x90/0xf0 [libcfs]
[15148.369222] [<0>] lbug_with_loc+0x4c/0xa0 [libcfs]
[15148.369245] [<0>] dt_record_write+0xc2/0x130 [obdclass]
[15148.369288] [<0>] out_tx_write_exec+0x9d/0x370 [ptlrpc]
[15148.369319] [<0>] out_tx_end+0xe1/0x600 [ptlrpc]
[15148.369349] [<0>] out_handle+0x1baf/0x2420 [ptlrpc]
[15148.369378] [<0>] tgt_request_handle+0x883/0x19a0 [ptlrpc]
[15148.369409] [<0>] handle_recovery_req+0x93/0x3c0 [ptlrpc]
[15148.369438] [<0>] replay_request_or_update.isra.25+0x31c/0x9e0 [ptlrpc]
[15148.369466] [<0>] target_recovery_thread+0x7bc/0x13d0 [ptlrpc]
[15148.369469] [<0>] kthread+0xd1/0xe0
[15148.369472] [<0>] ret_from_fork_nospec_begin+0x21/0x21
[15148.369482] [<0>] 0xfffffffffffffffe
[15148.369483] Kernel panic - not syncing: LBUG
[15148.369831] CPU: 3 PID: 11399 Comm: tgt_recover_1 Kdump: loaded Tainted: G           OE  ------------   3.10.0-1160.49.1.el7_lustre.x86_64 #1
 

Accidentally reproduced it on the latest master working on the different problem with following test:

[root@vm2 tests]# git log HEAD --pretty=short -n1
commit d7d16447a00be217246f1d73ecaf43a05a832442
Author: Alex Zhuravlev <[e-mail]>    

    LU-17188 mdt: remove n from LDLM_DEBUG
[root@vm2 tests]# git diff
diff --git a/lustre/tests/replay-dual.sh b/lustre/tests/replay-dual.sh
index 85836e6..de6a1e7 100755
--- a/lustre/tests/replay-dual.sh
+++ b/lustre/tests/replay-dual.sh
@@ -1322,6 +1322,26 @@ test_33() { # LU-15935
 }
 run_test 33 "Check for OBD_INCOMPAT_MULTI_RPCS in last_rcvd after abort_recovery"
 
+test_34() {
+       lfs mkdir -i 0 /mnt/lustre/dir
+       for i in `seq 1 100`;
+       do
+               replay_barrier mds2
+               lfs getdirstripe /mnt/lustre/dir
+               dd if=/dev/urandom of=/mnt/lustre/dir/f$i bs=1M count=2
+               dd if=/dev/urandom of=/mnt/lustre/dir/f2$i bs=1M count=2
+               lfs getstripe -v /mnt/lustre/dir/f$i
+               lfs getstripe -v /mnt/lustre/dir/f2$i
+               lfs migrate -m $((i%2)) /mnt/lustre/dir #migrate to 0 or 1
+               rm -f /mnt/lustre/dir/f$i
+               rm -f /mnt/lustre/dir/f$i2
+               facet_failover mds2
+               lctl dk > logs$i
+               ls -aslh /mnt/lustre/dir | grep "????" && break
+       done
+}
+run_test 34 "bla bla"
+ 

How to reproduce:

[root@vm2 tests]# MDSCOUNT=2 bash ./llmount.sh
...
[root@vm2 tests]# ONLY=34 bash ./replay-dual.sh 

 

Issue Links

• is related to: LU-15139 sanity test_160h: dt_record_write() A...

Comments

[Sergey Cheremencev]

From the crash dump:

crash> dt_object ffff965171950500
struct dt_object {
  do_lu = {
    lo_header = 0xffff964fcae9abd0, 
    lo_dev = 0xffff96516fd68000, 
    lo_ops = 0xffffffffc10ec3a0 <osd_lu_obj_ops>, 
    lo_linkage = {
      next = 0xffff964fcae9ac08, 
      prev = 0xffff965170784c90
    }, 
    lo_dev_ref = {<No data fields>}
  }, 
  do_ops = 0xffffffffc10ec280 <osd_obj_ops>, 
  do_body_ops = 0xffffffffc10ed4e0 <osd_body_ops_new>, 
  do_index_ops = 0x0
} crash> p *((struct dt_object *)0xffff965171950500)->do_body_ops
$4 = {
  dbo_read = 0x0, 
  dbo_declare_write = 0xffffffffc10d1fa0 <osd_declare_write>, 
  dbo_write = 0x0, 
  dbo_bufs_get = 0x0, 
  dbo_bufs_put = 0x0, 
  dbo_read_prep = 0x0, 
  dbo_write_prep = 0x0, 
  dbo_declare_write_commit = 0x0, 
  dbo_write_commit = 0x0, 
  dbo_fiemap_get = 0x0, 
  dbo_declare_punch = 0x0, 
  dbo_punch = 0x0, 
  dbo_ladvise = 0x0, 
  dbo_declare_fallocate = 0x0, 
  dbo_fallocate = 0x0, 
  dbo_lseek = 0x0
}
 

It seems do_body_ops was not initialized with "osd_body_ops":

        obj->oo_dt.do_body_ops = &osd_body_ops_new;
        if (result == 0 && obj->oo_inode != NULL) {
                struct osd_thread_info *oti = osd_oti_get(env);
                struct lustre_ost_attrs *loa = &oti->oti_ost_attrs;                osd_object_init0(obj);
                if (unlikely(obj->oo_header))
                        return 0;                result = osd_get_lma(oti, obj->oo_inode,
                                     &oti->oti_obj_dentry, loa);
                if (!result) {
                        /*
                         * Convert LMAI flags to lustre LMA flags
                         * and cache it to oo_lma_flags
                         */
                        obj->oo_lma_flags =
                                lma_to_lustre_flags(loa->loa_lma.lma_incompat);
                } else if (result == -ENODATA) {
                        result = 0; 
                }
        } 

[Alex Zhuravlev]

what branch do you hit this with ?

[Sergey Cheremencev]

what branch do you hit this with ?

master

[root@vm2 tests]# git log HEAD --pretty=short -n1
commit d7d16447a00be217246f1d73ecaf43a05a832442
Author: Alex Zhuravlev <[e-mail]>    

    LU-17188 mdt: remove n from LDLM_DEBUG 

[Alex Zhuravlev]

It seems do_body_ops was not initialized with "osd_body_ops":

it is initialized when/if object exists

[Alex Zhuravlev]

that's because MDSCOUNT=2 is not set for replay-dual, thus few variables configuring MDS2 were set propely in t-f and then:
do_facet mds2 /mnt/build/lustre/utils/lctl --device notransno is called with empty device.
as a result MDS2 keeps reporting transactions committed while the underlying device were ignoring writes.

[Alex Zhuravlev]

IMO, this is not a bug in Lustre, rather a problem in the testing infrastructure.