Bug 1266880

+++ This bug was initially created as a clone of Bug #1236032 +++

Description of problem:

Unlink operation failed after attaching tier to a volume that contain some files/directory 


Version-Release number of selected component (if applicable):

master


How reproducible:

100%

Steps to Reproduce:
1.create a distributed volume
2.start and create some files
3.attach a tier. (enable ctr, etc)
4.Remove some files from the mount point

Actual results:

failed with Invalid argument

Expected results:

unlink should success

Additional info:

unlink failed because dht translator doesn't have any cached subvolume for that particular inode in the inode ctx variable.

--- Additional comment from Mohammed Rafi KC on 2015-06-30 05:39:51 EDT ---


Changing the steps to reproduce :


Steps to Reproduce:
1.create a distributed volume
2.start and create some files
3.attach a tier. (enable ctr, etc)
4.do ls on mount point
4.Remove some files from the mount point

--- Additional comment from Joseph Elwin Fernandes on 2015-07-06 03:35:47 EDT ---

This issue is due to the NULL cached_subvolume in hot-dht xlator after tiering translator. Had a discussion with Dan on this he said he has a fix for this as he has dealt with this issue for other FOPS. This issue also happens for getxattr "trusted.distribute.linkinfo". 


BT when break point at : dht_unlink_linkfile_cbk

(gdb) bt
#0  dht_unlink_linkfile_cbk (frame=0x7fddb40086dc, cookie=0x7fddb400796c, this=0x7fddbc0162d0, op_ret=-1, 
    op_errno=22, preparent=0x0, postparent=0x0, xdata=0x0) at dht-common.c:2403
#1  0x00007fddc9598b5a in dht_unlink (frame=0x7fddb400796c, this=0x7fddbc015510, loc=0x7fddb400625c, xflag=0, 
    xdata=0x0) at dht-common.c:5208
#2  0x00007fddc9598798 in dht_unlink (frame=0x7fddb40086dc, this=0x7fddbc0162d0, loc=0x7fddb400625c, xflag=0, 
    xdata=0x0) at dht-common.c:5196
#3  0x00007fddd6af96c9 in default_unlink (frame=0x7fddb40086dc, this=0x7fddbc017b70, loc=0x7fddb400625c, xflag=0, 
    xdata=0x0) at defaults.c:1910
#4  0x00007fddd6af96c9 in default_unlink (frame=0x7fddb40086dc, this=0x7fddbc0189b0, loc=0x7fddb400625c, xflag=0, 
    xdata=0x0) at defaults.c:1910
#5  0x00007fddd6af96c9 in default_unlink (frame=0x7fddb40086dc, this=0x7fddbc019720, loc=0x7fddb400625c, xflag=0, 
    xdata=0x0) at defaults.c:1910
#6  0x00007fddd6af5364 in default_unlink_resume (frame=0x7fddb40058ec, this=0x7fddbc01a550, loc=0x7fddb400625c, 
    xflag=0, xdata=0x0) at defaults.c:1469
#7  0x00007fddd6b16817 in call_resume_wind (stub=0x7fddb400621c) at call-stub.c:2083
#8  0x00007fddd6b1ef1e in call_resume (stub=0x7fddb400621c) at call-stub.c:2571
#9  0x00007fddc8d21a58 in open_and_resume (this=0x7fddbc01a550, fd=0x0, stub=0x7fddb400621c) at open-behind.c:242
#10 0x00007fddc8d2468f in ob_unlink (frame=0x7fddb40058ec, this=0x7fddbc01a550, loc=0x7fddb40016e0, xflags=0, 
    xdata=0x0) at open-behind.c:768
#11 0x00007fddc8b12c6b in mdc_unlink (frame=0x7fddb40056fc, this=0x7fddbc01b310, loc=0x7fddb40016e0, xflag=0, 
    xdata=0x0) at md-cache.c:1205
#12 0x00007fddc88fda67 in io_stats_unlink (frame=0x7fddb40055fc, this=0x7fddbc01c0d0, loc=0x7fddb40016e0, xflag=0, 
    xdata=0x0) at io-stats.c:2002
#13 0x00007fddd6af96c9 in default_unlink (frame=0x7fddb40055fc, this=0x7fddbc01d170, loc=0x7fddb40016e0, xflag=0, 
    xdata=0x0) at defaults.c:1910
#14 0x00007fddcdef230b in fuse_unlink_resume (state=0x7fddb40016c0) at fuse-bridge.c:1568
#15 0x00007fddcdeebe47 in fuse_fop_resume (state=0x7fddb40016c0) at fuse-bridge.c:536
#16 0x00007fddcdee9b49 in fuse_resolve_done (state=0x7fddb40016c0) at fuse-resolve.c:637
#17 0x00007fddcdee9c1f in fuse_resolve_all (state=0x7fddb40016c0) at fuse-resolve.c:664
#18 0x00007fddcdee9b2a in fuse_resolve (state=0x7fddb40016c0) at fuse-resolve.c:628
#19 0x00007fddcdee9bf6 in fuse_resolve_all (state=0x7fddb40016c0) at fuse-resolve.c:660
#20 0x00007fddcdee9c7d in fuse_resolve_continue (state=0x7fddb40016c0) at fuse-resolve.c:680
#21 0x00007fddcdee9041 in fuse_resolve_parent (state=0x7fddb40016c0) at fuse-resolve.c:290
#22 0x00007fddcdee9afa in fuse_resolve (state=0x7fddb40016c0) at fuse-resolve.c:621
#23 0x00007fddcdee9ba1 in fuse_resolve_all (state=0x7fddb40016c0) at fuse-resolve.c:653
#24 0x00007fddcdee9cbb in fuse_resolve_and_resume (state=0x7fddb40016c0, fn=0x7fddcdef1e94 <fuse_unlink_resume>)
    at fuse-resolve.c:692
#25 0x00007fddcdef240c in fuse_unlink (this=0x20a0be0, finh=0x7fddb4008d30, msg=0x7fddb4008d58)
    at fuse-bridge.c:1582
#26 0x00007fddcdf02087 in fuse_thread_proc (data=0x20a0be0) at fuse-bridge.c:4879
#27 0x00007fddd593652a in start_thread () from /lib64/libpthread.so.0
---Type <return> to continue, or q <return> to quit---
#28 0x00007fddd528522d in clone () from /lib64/libc.so.6


Point to be noted here is cached_subvol is NULL and hence op_errno is set to EINVAL

#1  0x00007fddc9598b5a in dht_unlink (frame=0x7fddb400796c, this=0x7fddbc015510, loc=0x7fddb400625c, xflag=0, 
    xdata=0x0) at dht-common.c:5208
5208	        DHT_STACK_UNWIND (unlink, frame, -1, op_errno, NULL, NULL, NULL);
(gdb) p hashed_subvol
$8 = (xlator_t *) 0x7fddbc012f70

(gdb) p cached_subvol
$3 = (xlator_t *) 0x0

(gdb) p op_errno
$4 = 22

(gdb) p local
$6 = (dht_local_t *) 0x7fddb4008e5c

(gdb) p local->cached_subvol
$7 = (xlator_t *) 0x0
(gdb)

(gdb) p this->name
$9 = 0x7fddbc00c6a0 "test-hot-dht"
(gdb) 



dht_local_init (frame, loc, NULL, GF_FOP_UNLINK); in line 5170 of dht-common.c has failed to populate cached_subvol.  dht_subvol_get_cached() seems to be broken for hot-dht xaltor.

when looked into 
dht_subvol_get_cached (this=0x7fddbc015510, inode=0x7fddbc03b70c) at dht-helper.c:626
626	        dht_layout_t *layout = NULL;
(gdb) bt
#0  dht_subvol_get_cached (this=0x7fddbc015510, inode=0x7fddbc03b70c) at dht-helper.c:626
#1  0x00007fddc955ae7d in dht_local_init (frame=0x7fddb400751c, loc=0x7fddb400654c, fd=0x0, fop=GF_FOP_UNLINK)
    at dht-helper.c:498
#2  0x00007fddc95984b3 in dht_unlink (frame=0x7fddb400751c, this=0x7fddbc015510, loc=0x7fddb400654c, xflag=0, 
    xdata=0x0) at dht-common.c:5170
#3  0x00007fddc9598798 in dht_unlink (frame=0x7fddb400741c, this=0x7fddbc0162d0, loc=0x7fddb400654c, xflag=0, 
    xdata=0x0) at dht-common.c:5196
#4  0x00007fddd6af96c9 in default_unlink (frame=0x7fddb400741c, this=0x7fddbc017b70, loc=0x7fddb400654c, xflag=0, 
    xdata=0x0) at defaults.c:1910
#5  0x00007fddd6af96c9 in default_unlink (frame=0x7fddb400741c, this=0x7fddbc0189b0, loc=0x7fddb400654c, xflag=0, 
    xdata=0x0) at defaults.c:1910
#6  0x00007fddd6af96c9 in default_unlink (frame=0x7fddb400741c, this=0x7fddbc019720, loc=0x7fddb400654c, xflag=0, 
    xdata=0x0) at defaults.c:1910
#7  0x00007fddd6af5364 in default_unlink_resume (frame=0x7fddb400640c, this=0x7fddbc01a550, loc=0x7fddb400654c

627	        xlator_t     *subvol = NULL;
(gdb) 
629	        GF_VALIDATE_OR_GOTO (this->name, this, out);
(gdb) 
630	        GF_VALIDATE_OR_GOTO (this->name, inode, out);
(gdb) 
632	        layout = dht_layout_get (this, inode);
(gdb) n
634	        if (!layout) {
(gdb) p layout
$18 = (dht_layout_t *) 0x0
(gdb) p this->name
$19 = 0x7fddbc00c6a0 "test-hot-dht"
(gdb)

dht_layout_get return NULL. As a result dht_subvol_get_cached also return NULL.

When looked deeper we see dht_inode_ctx_t is NULL!

Breakpoint 1, dht_subvol_get_cached (this=0x7fddbc015510, inode=0x7fddbc03b70c) at dht-helper.c:626
626	        dht_layout_t *layout = NULL;
(gdb) n
627	        xlator_t     *subvol = NULL;
(gdb) n
629	        GF_VALIDATE_OR_GOTO (this->name, this, out);
(gdb) n
630	        GF_VALIDATE_OR_GOTO (this->name, inode, out);
(gdb) n
632	        layout = dht_layout_get (this, inode);
(gdb) s
dht_layout_get (this=0x7fddbc015510, inode=0x7fddbc03b70c) at dht-layout.c:65
65	        dht_conf_t   *conf = NULL;
(gdb) n
66	        dht_layout_t *layout = NULL;
(gdb) n
67	        int           ret = 0;
(gdb) n
69	        conf = this->private;
(gdb) n
70	        if (!conf)
(gdb) n
73	        LOCK (&conf->layout_lock);
(gdb) n
75	                ret = dht_inode_ctx_layout_get (inode, this, &layout);
(gdb) s
dht_inode_ctx_layout_get (inode=0x7fddbc03b70c, this=0x7fddbc015510, layout=0x7fddc37fd678) at dht-common.c:6981
6981	        dht_inode_ctx_t         *ctx            = NULL;
(gdb) n
6982	        int                      ret            = -1;
(gdb) n
6984	        ret = dht_inode_ctx_get (inode, this, &ctx);
(gdb) n
6986	        if (!ret && ctx) {
(gdb) p ctx
$10 = (dht_inode_ctx_t *) 0x0
(gdb)

--- Additional comment from Joseph Elwin Fernandes on 2015-07-06 03:42:27 EDT ---

This issue only happens in a pure distribute case! not on a Dis-rep or Dis-EC.

--- Additional comment from Mohammed Rafi KC on 2015-07-10 05:48:16 EDT ---

RCA.

Since, all of the fops will be hashed to hot_tier after attach-tier (unless explicitly set the "rule" option), the lookups sent to directory, will eventually search the directory using readdirp, and will populate inode_ctx for the inodes based on the output, in respective dht_xlators. So the readdirp will populate inodes_ctx for the files (that is already being present in volume before attaching) in cold-dht, only because it got the entries from the cold-tier.

So when an unlink comes on such an inode, the lookup associated with the unlink will be send as a re validate request to cold-tier only, since already a lookup was performed on the inode, and the new lookup will succeed. So from the unlink of dht, it will hash to cold-tier but the cached_subvol will be cold, since there is a mismatch in hash and cach , it chose hashed subvolume and will sent the fop to hot dht, and the fops fail with EINVAL from the hot-dht since it does not have inode_ctx stored for that inode (because, no lookup was performed from hot-dht).

--- Additional comment from Mohammed Rafi KC on 2015-07-10 07:22:43 EDT ---

The same problem could be there for the following FOP's too.

1) dht_link,
2) getxattr "trusted.distribute.linkinfo"
3) f/setxattr
4) f/removexattr
5) unlink of a link file

--- Additional comment from Anand Avati on 2015-07-21 08:53:46 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#2) for review on master by mohammed rafi  kc (rkavunga)

--- Additional comment from Anand Avati on 2015-08-06 02:48:17 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#3) for review on master by mohammed rafi  kc (rkavunga)

--- Additional comment from Anand Avati on 2015-08-13 07:33:06 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#5) for review on master by mohammed rafi  kc (rkavunga)

--- Additional comment from Anand Avati on 2015-08-13 16:04:40 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#6) for review on master by Dan Lambright (dlambrig)

--- Additional comment from Anand Avati on 2015-08-13 16:44:45 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#7) for review on master by Dan Lambright (dlambrig)

--- Additional comment from Anand Avati on 2015-08-14 02:35:40 EDT ---

REVIEW: http://review.gluster.org/11892 (fuse:sent at least one lookup before actual fop) posted (#2) for review on master by mohammed rafi  kc (rkavunga)

--- Additional comment from Anand Avati on 2015-08-14 10:55:00 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#8) for review on master by Dan Lambright (dlambrig)

--- Additional comment from Anand Avati on 2015-08-19 01:43:03 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#9) for review on master by Dan Lambright (dlambrig)

--- Additional comment from Anand Avati on 2015-08-21 06:55:57 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#10) for review on master by Dan Lambright (dlambrig)

--- Additional comment from Anand Avati on 2015-08-21 11:51:12 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#11) for review on master by Joseph Fernandes

--- Additional comment from Anand Avati on 2015-08-27 13:14:18 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#12) for review on master by Dan Lambright (dlambrig)

--- Additional comment from Vijay Bellur on 2015-09-03 05:37:12 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#13) for review on master by Joseph Fernandes

--- Additional comment from Vijay Bellur on 2015-09-04 05:09:25 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#14) for review on master by mohammed rafi  kc (rkavunga)

--- Additional comment from Vijay Bellur on 2015-09-09 05:13:55 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#16) for review on master by mohammed rafi  kc (rkavunga)

--- Additional comment from Vijay Bellur on 2015-09-12 10:23:15 EDT ---

REVIEW: http://review.gluster.org/11892 (fuse:sent at least one lookup before actual fop) posted (#3) for review on master by Dan Lambright (dlambrig)

--- Additional comment from Vijay Bellur on 2015-09-14 04:53:43 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#17) for review on master by mohammed rafi  kc (rkavunga)

--- Additional comment from Vijay Bellur on 2015-09-15 01:39:21 EDT ---

REVIEW: http://review.gluster.org/11675 (tier/dht: unlink fails after lookup in a directory) posted (#18) for review on master by mohammed rafi  kc (rkavunga)