[Gluster-devel] query about why glustershd can not afr_selfheal_recreate_entry because of "afr: Prevent null gfids in self-heal entry re-creation"

Tue Jan 16 08:52:18 UTC 2018

Hi,

Thanks a lots for your update.

I would like try to introduce more detail for which the issue came from.

This issue is came from a test case in our team, it is the step like the following:

1)    Setup a glusterfs ENV with replicate 2 storage server nodes and 2 client nodes

2)    Generate a split-brain file , sn-0 is normal, sn-1 is dirty.

3)    Delete the directory before heal begin  (in this phase, the normal correct file in sn-0 is deleted by “rm” command , dirty file is still there )

4)    After that, the self-heal process will always be failure with the log which attached in last mail

Also attach some command output FYI.
From my understand , the Glusterfs maybe can’t handle the split-brain file in this case, could you share your comments and confirm whether do some enhancement for this case or not?

rm -rf /mnt/export/testdir rm: cannot remove '/mnt/export/testdir/test file': No data available

[root at sn-1:/root]
# ls -l /mnt/export/testdir/
ls: cannot access '/mnt/export/testdir/IORFILE_82_2': No data available
total 0
-????????? ? ? ? ?            ? test_file

[root at sn-1:/root]
# getfattr -m . -d -e hex /mnt/bricks/export/brick/testdir/
getfattr: Removing leading '/' from absolute path names
# file: mnt/bricks/export/brick/testdir/
trusted.afr.dirty=0x000000000000000000000001
trusted.afr.export-client-0=0x000000000000000000000054
trusted.gfid=0xb217d6af49024f189a69e0ccf5207572
trusted.glusterfs.dht=0x000000010000000000000000ffffffff

[root at sn-0:/var/log/glusterfs]
#  getfattr -m . -d -e hex /mnt/bricks/export/brick/testdir/
getfattr: Removing leading '/' from absolute path names
# file: mnt/bricks/export/brick/testdir/
trusted.gfid=0xb217d6af49024f189a69e0ccf5207572
trusted.glusterfs.dht=0x000000010000000000000000ffffffff

Best Regards
George
From: gluster-devel-bounces at gluster.org [mailto:gluster-devel-bounces at gluster.org] On Behalf Of Ravishankar N
Sent: Tuesday, January 16, 2018 1:44 PM
To: Zhou, Cynthia (NSB - CN/Hangzhou) <cynthia.zhou at nokia-sbell.com>; Gluster Devel <gluster-devel at gluster.org>
Subject: Re: [Gluster-devel] query about why glustershd can not afr_selfheal_recreate_entry because of "afr: Prevent null gfids in self-heal entry re-creation"

+ gluster-devel

On 01/15/2018 01:41 PM, Zhou, Cynthia (NSB - CN/Hangzhou) wrote:
Hi glusterfs expert,
        Good day,
        When I do some test about glusterfs self-heal I find following prints showing when dir/file type get error it cannot get self-healed.
Could you help to check if it is an expected behavior ? because I find the code change https://review.gluster.org/#/c/17981/ add check for iatt->ia_type,  so what if a file’s ia_type get corrupted ? in this case it should not get self-healed ?

Yes, without knowing the ia-type , afr_selfheal_recreate_entry () cannot decide what type of FOP to do (mkdir/link/mknod ) to create the appropriate file on the sink. You would need to find out why the source brick is not returning valid ia_type. i.e. why replies[source].poststat is not valid.
Thanks,
Ravi

Thanks!
//////////////////heal info output////////////////////////////
[root at sn-0:/home/robot]
# gluster v heal export info
Brick sn-0.local:/mnt/bricks/export/brick
Status: Connected
Number of entries: 0

Brick sn-1.local:/mnt/bricks/export/brick
/testdir - Is in split-brain

Status: Connected
Number of entries: 1
//////////////////////////////////////////sn-1 glustershd log///////////////////////////////////////////////////

[2018-01-15 03:53:40.011422] I [MSGID: 108026] [afr-self-heal-entry.c:887:afr_selfheal_entry_do] 0-export-replicate-0: performing entry selfheal on b217d6af-4902-4f18-9a69-e0ccf5207572
[2018-01-15 03:53:40.013994] W [MSGID: 114031] [client-rpc-fops.c:2860:client3_3_lookup_cbk] 0-export-client-1: remote operation failed. Path: (null) (00000000-0000-0000-0000-000000000000) [No data available]
[2018-01-15 03:53:40.014025] E [MSGID: 108037] [afr-self-heal-entry.c:92:afr_selfheal_recreate_entry] 0-export-replicate-0: Invalid ia_type (0) or gfid(00000000-0000-0000-0000-000000000000). source brick=1, pargfid=00000000-0000-0000-0000-000000000000, name=IORFILE_82_2
//////////////////////////////////////gdb attached to sn-1 glustershd/////////////////////////////////////////////
root at sn-1:/var/log/glusterfs]
# gdb attach 2191
GNU gdb (GDB) 8.0.1
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
attach: No such file or directory.
Attaching to process 2191
[New LWP 2192]
[New LWP 2193]
[New LWP 2194]
[New LWP 2195]
[New LWP 2196]
[New LWP 2197]
[New LWP 2239]
[New LWP 2241]
[New LWP 2243]
[New LWP 2245]
[New LWP 2247]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
0x00007f90aca037bd in __pthread_join (threadid=140259279345408, thread_return=0x0) at pthread_join.c:90
90      pthread_join.c: No such file or directory.
(gdb) break afr_selfheal_recreate_entry
Breakpoint 1 at 0x7f90a3b56dec: file afr-self-heal-entry.c, line 73.
(gdb) c
Continuing.
[Switching to Thread 0x7f90a1b8e700 (LWP 2241)]

Thread 9 "glustershdheal" hit Breakpoint 1, afr_selfheal_recreate_entry (frame=0x7f90980018d0, dst=0, source=1, sources=0x7f90a1b8ceb0 "", dir=0x7f9098011940, name=0x7f909c015d48 "IORFILE_82_2",
    inode=0x7f9098001bd0, replies=0x7f90a1b8c890) at afr-self-heal-entry.c:73
73      afr-self-heal-entry.c: No such file or directory.
(gdb) n
74      in afr-self-heal-entry.c
(gdb) n
75      in afr-self-heal-entry.c
(gdb) n
76      in afr-self-heal-entry.c
(gdb) n
77      in afr-self-heal-entry.c
(gdb) n
78      in afr-self-heal-entry.c
(gdb) n
79      in afr-self-heal-entry.c
(gdb) n
80      in afr-self-heal-entry.c
(gdb) n
81      in afr-self-heal-entry.c
(gdb) n
82      in afr-self-heal-entry.c
(gdb) n
83      in afr-self-heal-entry.c
(gdb) n
85      in afr-self-heal-entry.c
(gdb) n
86      in afr-self-heal-entry.c
(gdb) n
87      in afr-self-heal-entry.c
(gdb) print iatt->ia_type
$1 = IA_INVAL
(gdb) print gf_uuid_is_null(iatt->ia_gfid)
$2 = 1
(gdb) bt
#0  afr_selfheal_recreate_entry (frame=0x7f90980018d0, dst=0, source=1, sources=0x7f90a1b8ceb0 "", dir=0x7f9098011940, name=0x7f909c015d48 "IORFILE_82_2", inode=0x7f9098001bd0, replies=0x7f90a1b8c890)
    at afr-self-heal-entry.c:87
#1  0x00007f90a3b57d20 in __afr_selfheal_merge_dirent (frame=0x7f90980018d0, this=0x7f90a4024610, fd=0x7f9098413090, name=0x7f909c015d48 "IORFILE_82_2", inode=0x7f9098001bd0,
    sources=0x7f90a1b8ceb0 "", healed_sinks=0x7f90a1b8ce70 "\001\001A\230\220\177", locked_on=0x7f90a1b8ce50 "\001\001\270\241\220\177", replies=0x7f90a1b8c890) at afr-self-heal-entry.c:360
#2  0x00007f90a3b57da5 in __afr_selfheal_entry_dirent (frame=0x7f90980018d0, this=0x7f90a4024610, fd=0x7f9098413090, name=0x7f909c015d48 "IORFILE_82_2", inode=0x7f9098001bd0, source=-1,
    sources=0x7f90a1b8ceb0 "", healed_sinks=0x7f90a1b8ce70 "\001\001A\230\220\177", locked_on=0x7f90a1b8ce50 "\001\001\270\241\220\177", replies=0x7f90a1b8c890) at afr-self-heal-entry.c:379
#3  0x00007f90a3b5881f in afr_selfheal_entry_dirent (frame=0x7f90980018d0, this=0x7f90a4024610, fd=0x7f9098413090, name=0x7f909c015d48 "IORFILE_82_2", parent_idx_inode=0x0, subvol=0x7f90a4022240,
    full_crawl=_gf_true) at afr-self-heal-entry.c:610
#4  0x00007f90a3b58da8 in afr_selfheal_entry_do_subvol (frame=0x7f90980110f0, this=0x7f90a4024610, fd=0x7f9098413090, child=1) at afr-self-heal-entry.c:742
#5  0x00007f90a3b5953a in afr_selfheal_entry_do (frame=0x7f90980110f0, this=0x7f90a4024610, fd=0x7f9098413090, source=-1, sources=0x7f90a1b8d810 "",
    healed_sinks=0x7f90a1b8d7d0 "\001\001\270\241\220\177") at afr-self-heal-entry.c:908
#6  0x00007f90a3b59b79 in __afr_selfheal_entry (frame=0x7f90980110f0, this=0x7f90a4024610, fd=0x7f9098413090, locked_on=0x7f90a1b8d920 "\001\001\\Z") at afr-self-heal-entry.c:1002
#7  0x00007f90a3b5a051 in afr_selfheal_entry (frame=0x7f90980110f0, this=0x7f90a4024610, inode=0x7f9098011940) at afr-self-heal-entry.c:1112
#8  0x00007f90a3b519b1 in afr_selfheal_do (frame=0x7f90980110f0, this=0x7f90a4024610, gfid=0x7f90a1b8db20 "\262\027֯I\002O\030\232i\340\314\365 urP۸\241\220\177") at afr-self-heal-common.c:2459
#9  0x00007f90a3b51aa7 in afr_selfheal (this=0x7f90a4024610, gfid=0x7f90a1b8db20 "\262\027֯I\002O\030\232i\340\314\365 urP۸\241\220\177") at afr-self-heal-common.c:2500
#10 0x00007f90a3b5cf1f in afr_shd_selfheal (healer=0x7f90a4033510, child=1, gfid=0x7f90a1b8db20 "\262\027֯I\002O\030\232i\340\314\365 urP۸\241\220\177") at afr-self-heald.c:334
#11 0x00007f90a3b5d2c8 in afr_shd_index_heal (subvol=0x7f90a4022240, entry=0x7f909c0169c0, parent=0x7f90a1b8dde0, data=0x7f90a4033510) at afr-self-heald.c:431
#12 0x00007f90adc74654 in syncop_mt_dir_scan (frame=0x7f90a407b4f0, subvol=0x7f90a4022240, loc=0x7f90a1b8dde0, pid=-6, data=0x7f90a4033510, fn=0x7f90a3b5d17c <afr_shd_index_heal>,
    xdata=0x7f90a4002380, max_jobs=1, max_qlen=1024) at syncop-utils.c:407
#13 0x00007f90a3b5d4e1 in afr_shd_index_sweep (healer=0x7f90a4033510, vgfid=0x7f90a3b84f38 "glusterfs.xattrop_index_gfid") at afr-self-heald.c:481
#14 0x00007f90a3b5d5bd in afr_shd_index_sweep_all (healer=0x7f90a4033510) at afr-self-heald.c:504
#15 0x00007f90a3b5d894 in afr_shd_index_healer (data=0x7f90a4033510) at afr-self-heald.c:584
#16 0x00007f90aca024a5 in start_thread (arg=0x7f90a1b8e700) at pthread_create.c:465
#17 0x00007f90ac2e959f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
(gdb)

Best regards,
Cynthia （周琳）
MBB SM HETRAN SW3 MATRIX
Storage
Mobile: +86 (0)18657188311

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