Re: [PATCH v2] ceph: do not update snapshot context when there is no new snapshot

["Luís Henriques" <lhenriques@suse.de>]

Hi!

I'm seeing the BUG below when running a simple fsstress on an encrypted
directory.  Reverting this commit seems to make it go away, but I'm not
yet 100% sure this is the culprit (I just wanted to report it before going
offline for the weekend.)

I stared at this code for a bit, but no light so far.

Cheers,
-- 
Luís

[   43.593441] ------------[ cut here ]------------                                                                                                                          
[   43.595707] kernel BUG at fs/ceph/addr.c:108!
[   43.598354] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[   43.601563] CPU: 0 PID: 232 Comm: fsstress Not tainted 5.17.0-rc2+ #62
[   43.604225] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[   43.607957] RIP: 0010:ceph_set_page_dirty+0x1eb/0x1f0 [ceph]
[   43.610909] Code: 55 51 83 e9 01 50 51 48 c7 c1 df 50 0d a0 52 ff 73 20 ba 03 00 00 00 53 41 ff 34 24 e8 2e 31 2f e1 48 83 c4 50 e9 f0 fe ff ff <0f> 0b 0f 1f 00 0f 1f 44f
[   43.619910] RSP: 0018:ffffc900002cb9c8 EFLAGS: 00010246
[   43.621662] RAX: ffff888005e65ff0 RBX: ffffea0001fac3c0 RCX: 0000000000000001
[   43.624036] RDX: ffff888005e65ff0 RSI: 000000000037b280 RDI: 0000000000000000
[   43.626441] RBP: ffff888005e66180 R08: 0000000000000f8a R09: ffffea0001fac3c0
[   43.629834] R10: ffff88800b567e10 R11: 0000000000001000 R12: ffff888005e662e0
[   43.633396] R13: 0000000000000000 R14: ffff888005e65e10 R15: 0000000000000f8a
[   43.637012] FS:  00007fdc23f7fb80(0000) GS:ffff888071200000(0000) knlGS:0000000000000000
[   43.641055] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   43.643799] CR2: 00007ff30428d008 CR3: 00000000043b6000 CR4: 00000000000006b0
[   43.646667] Call Trace:
[   43.647694]  <TASK>
[   43.648579]  folio_mark_dirty+0x36/0x50
[   43.650166]  ceph_write_end+0x53/0x100 [ceph]
[   43.651734]  generic_perform_write+0xfe/0x1d0
[   43.653263]  ceph_write_iter+0x5b5/0x790 [ceph]
[   43.654864]  do_iter_readv_writev+0x14d/0x1d0
[   43.656295]  do_iter_write+0x85/0x1f0
[   43.657491]  iter_file_splice_write+0x253/0x370
[   43.658858]  direct_splice_actor+0x2c/0x40
[   43.660797]  splice_direct_to_actor+0xf8/0x220
[   43.662209]  ? opipe_prep.part.19+0xb0/0xb0
[   43.663493]  do_splice_direct+0x9a/0xd0
[   43.664684]  generic_copy_file_range+0x32/0x40
[   43.666055]  ceph_copy_file_range+0xb3/0xa10 [ceph]
[   43.667455]  ? _raw_spin_unlock+0x12/0x30
[   43.668475]  ? __ceph_do_getattr+0x7a/0x240 [ceph]
[   43.669724]  ? _copy_to_user+0x1c/0x30
[   43.670654]  ? cp_new_stat+0x12b/0x160
[   43.671569]  vfs_copy_file_range+0x26c/0x510
[   43.672609]  __x64_sys_copy_file_range+0x12d/0x1d0
[   43.673759]  do_syscall_64+0x42/0x90
[   43.674607]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   43.675875] RIP: 0033:0x7fdc240a695d
[   43.677114] Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 018
[   43.683105] RSP: 002b:00007ffef97a53a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000146
[   43.685395] RAX: ffffffffffffffda RBX: 0000000000000051 RCX: 00007fdc240a695d
[   43.687528] RDX: 0000000000000005 RSI: 00007ffef97a53e0 RDI: 0000000000000004
[   43.689596] RBP: 0000000000000004 R08: 000000000001471b R09: 0000000000000000
[   43.691550] R10: 00007ffef97a53e8 R11: 0000000000000246 R12: 0000000000000005
[   43.693490] R13: 00000000002d3c32 R14: 000000000001471b R15: 00000000004be076
[   43.695375]  </TASK>
[   43.695960] Modules linked in: ceph libceph
[   43.697060] ---[ end trace 0000000000000000 ]---
[   43.698259] RIP: 0010:ceph_set_page_dirty+0x1eb/0x1f0 [ceph]
[   43.699676] Code: 55 51 83 e9 01 50 51 48 c7 c1 df 50 0d a0 52 ff 73 20 ba 03 00 00 00 53 41 ff 34 24 e8 2e 31 2f e1 48 83 c4 50 e9 f0 fe ff ff <0f> 0b 0f 1f 00 0f 1f 44f
[   43.704183] RSP: 0018:ffffc900002cb9c8 EFLAGS: 00010246
[   43.705424] RAX: ffff888005e65ff0 RBX: ffffea0001fac3c0 RCX: 0000000000000001
[   43.707116] RDX: ffff888005e65ff0 RSI: 000000000037b280 RDI: 0000000000000000
[   43.708718] RBP: ffff888005e66180 R08: 0000000000000f8a R09: ffffea0001fac3c0
[   43.709866] R10: ffff88800b567e10 R11: 0000000000001000 R12: ffff888005e662e0
[   43.710923] R13: 0000000000000000 R14: ffff888005e65e10 R15: 0000000000000f8a
[   43.711995] FS:  00007fdc23f7fb80(0000) GS:ffff888071200000(0000) knlGS:0000000000000000
[   43.713189] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   43.714069] CR2: 00007ff30428d008 CR3: 00000000043b6000 CR4: 00000000000006b0
[   43.715093] note: fsstress[232] exited with preempt_count 1