On Mon, 6 Nov 2017 11:18:09 Mike Snitzer wrote:
> On Thu, Nov 02 2017 at 4:39pm -0400, Bruno Prémont wrote:
> > Hi,
> >
> > Between 4.11 and 4.12 I stopped being able to boot my system with root
> > partition encrypted with dm-crypt (issue still present in 4.14-rc7).
> > The system was able to open the dm-crypt device and read-only mount the
> > XFS root partition on it.
> > Later read-write remounting though caused XFS to shutdown the filesystem
> > on IO error.
> >
> > Some reports found online indicated a possible coincidence with stack
> > protection or the like as well as use of slub_debug, the latter causing
> > the IO errors to surface for me (I have slub_debug=ZP on my kernel
> > cmdline).
> >
> > I finally got time to go and bisect in order to find the triggering
> > patch. Bisect log:
> >
> > # good: [a351e9b9fc24e982ec2f0e76379a49826036da12] Linux 4.11
> > git bisect good a351e9b9fc24e982ec2f0e76379a49826036da12
> > # bad: [6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c] Linux 4.12
> > git bisect bad 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c
> > # bad: [2bd80401743568ced7d303b008ae5298ce77e695] Merge tag 'gpio-v4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
> > git bisect bad 2bd80401743568ced7d303b008ae5298ce77e695
> > # good: [8d65b08debc7e62b2c6032d7fe7389d895b92cbc] Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
> > git bisect good 8d65b08debc7e62b2c6032d7fe7389d895b92cbc
> > # good: [8b03d1ed2c43a2ba5ef3381322ee4515b97381bf] Merge branch 'linux-4.12' of git://github.com/skeggsb/linux into drm-next
> > git bisect good 8b03d1ed2c43a2ba5ef3381322ee4515b97381bf
> > # bad: [e897f267c51812bfecec45771a2d835c1a2bdacf] Merge tag 'backlight-next-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight
> > git bisect bad e897f267c51812bfecec45771a2d835c1a2bdacf
> > # good: [46f0537b1ecf672052007c97f102a7e6bf0791e4] Merge branch 'stable-4.12' of git://git.infradead.org/users/pcmoore/audit
> > git bisect good 46f0537b1ecf672052007c97f102a7e6bf0791e4
> > # good: [20d5c84bef067b7e804a163e2abca16c47125bad] Merge remote-tracking branches 'asoc/topic/wm8960', 'asoc/topic/wm8978' and 'asoc/topic/zte-tdm' into asoc-next
> > git bisect good 20d5c84bef067b7e804a163e2abca16c47125bad
> > # bad: [7b66f13207e60e7c550af730986e77e38a0c69a3] Merge tag 'for-4.12/dm-post-merge-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
> > git bisect bad 7b66f13207e60e7c550af730986e77e38a0c69a3
> > # good: [dd7a8f5dee81ffb1794df1103f07c63fd4f1d766] md/raid5: make chunk_aligned_read() split bios more cleanly.
> > git bisect good dd7a8f5dee81ffb1794df1103f07c63fd4f1d766
> > # bad: [6625d903253eb6f003849823e22d7b8de5bfb5b2] dm integrity: use hex2bin instead of open-coded variant
> > git bisect bad 6625d903253eb6f003849823e22d7b8de5bfb5b2
> > # bad: [449b668ce0b9069fcaafa6344c7f10fa2ba9632e] dm cache: set/clear the cache core's dirty_bitset when loading mappings
> > git bisect bad 449b668ce0b9069fcaafa6344c7f10fa2ba9632e
> > # good: [33d2f09fcb357fd1861c4959d1d3505492bf91f8] dm crypt: introduce new format of cipher with "capi:" prefix
> > git bisect good 33d2f09fcb357fd1861c4959d1d3505492bf91f8
> > # bad: [ff3af92b4461be773337111daea80bb91b2cd545] dm crypt: use shifts instead of sector_div
> > git bisect bad ff3af92b4461be773337111daea80bb91b2cd545
> > # bad: [1aa0efd4210df1c57764b77040a6615bc9b3ac0f] dm integrity: factor out create_journal() from dm_integrity_ctr()
> > git bisect bad 1aa0efd4210df1c57764b77040a6615bc9b3ac0f
> > # bad: [8f0009a225171cc1b76a6b443de5137b26e1374b] dm crypt: optionally support larger encryption sector size
> > git bisect bad 8f0009a225171cc1b76a6b443de5137b26e1374b
> > # first bad commit: [8f0009a225171cc1b76a6b443de5137b26e1374b] dm crypt: optionally support larger encryption sector size
> >
> > In order to test on 4.12 I had to revert the following commits,
> > the first two having been applied on top of bad commit:
> > 583fe7474c05ee5523e14ef791ea59604cd846dc (dm crypt: fix large block integrity support)
> > ff3af92b4461be773337111daea80bb91b2cd545 (dm crypt: use shifts instead of sector_div)
> > 8f0009a225171cc1b76a6b443de5137b26e1374b (dm crypt: optionally support larger encryption sector size)
> >
> > From looking at 8f0009a225171cc1b76a6b443de5137b26e1374b I can't spot
> > direct cause though I assume there might be a mismatch in memory
> > allocation versus access sizes as a consequence of support for larger
> > encryption sector size (someplace 512 byte versus page size access
> > tripping on memory poison?).
>
> Thanks for bisecting this.
>
> Can you apply the following debug patch to see if either of these newer
> -EIO returns (introduced by commit 8f0009a225) are causing you problems
> for some reason?
>
> Thanks
>
> diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
> index 05acc42..daefe37 100644
> --- a/drivers/md/dm-crypt.c
> +++ b/drivers/md/dm-crypt.c
> @@ -1056,7 +1056,7 @@ static int crypt_convert_block_aead(struct crypt_config *cc,
> BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
>
> /* Reject unexpected unaligned bio. */
> - if (unlikely(bv_in.bv_offset & (cc->sector_size - 1)))
> + if (WARN_ON_ONCE(unlikely(bv_in.bv_offset & (cc->sector_size - 1)))))
> return -EIO;
>
> dmreq = dmreq_of_req(cc, req);
> @@ -1149,7 +1149,7 @@ static int crypt_convert_block_skcipher(struct crypt_config *cc,
> int r = 0;
>
> /* Reject unexpected unaligned bio. */
> - if (unlikely(bv_in.bv_offset & (cc->sector_size - 1)))
> + if (WARN_ON_ONCE(unlikely(bv_in.bv_offset & (cc->sector_size - 1))))
> return -EIO;
>
> dmreq = dmreq_of_req(cc, req);
This second one triggers:
[ 143.238220] ------------[ cut here ]------------
[ 143.238228] WARNING: CPU: 1 PID: 379 at /usr/src/linux-git/drivers/md/dm-crypt.c:1158 crypt_convert+0xd53/0x1070
[ 143.238229] Modules linked in:
[ 143.238233] CPU: 1 PID: 379 Comm: kworker/u17:3 Not tainted 4.12.14+ #2
[ 143.238234] Hardware name: FUJITSU LIFEBOOK U904/FJNB27D, BIOS Version 1.09 03/20/2014
[ 143.238236] Workqueue: kcryptd kcryptd_crypt
[ 143.238238] task: ffff982ccdf628c0 task.stack: ffffb3b5c0bb8000
[ 143.238240] RIP: 0010:crypt_convert+0xd53/0x1070
[ 143.238242] RSP: 0018:ffffb3b5c0bbbd28 EFLAGS: 00010202
[ 143.238243] RAX: 00000000000001ff RBX: ffff982ccbebafe0 RCX: ffffd8d08a2fc880
[ 143.238244] RDX: 0000000000000868 RSI: ffff982ccbebaf40 RDI: 0000000000000000
[ 143.238245] RBP: ffffb3b5c0bbbdd8 R08: 0000000000000000 R09: 0000000000000018
[ 143.238246] R10: ffffb3b5c0073e60 R11: ffffd8d08a2fc880 R12: 0000000000000000
[ 143.238247] R13: ffff982ccbebaf40 R14: ffff982ccdf5f308 R15: ffff982cd00dd288
[ 143.238248] FS: 0000000000000000(0000) GS:ffff982cde240000(0000) knlGS:0000000000000000
[ 143.238249] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 143.238251] CR2: 00007f45350793c4 CR3: 000000006b20a000 CR4: 00000000001406e0
[ 143.238251] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 143.238252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 143.238253] Call Trace:
[ 143.238256] kcryptd_crypt+0x32c/0x3a0
[ 143.238261] process_one_work+0x11c/0x340
[ 143.238264] worker_thread+0x43/0x3e0
[ 143.238267] kthread+0xfe/0x140
[ 143.238269] ? create_worker+0x1a0/0x1a0
[ 143.238271] ? kthread_create_on_node+0x40/0x40
[ 143.238275] ret_from_fork+0x22/0x30
[ 143.238276] Code: ff ff 49 8b 7e 10 be 00 00 40 01 e8 a8 2b 9c ff 49 89 45 70 e9 42 f3 ff ff 48 8b 75 c0 48 8b 7d c8 e8 52 34 c1 ff e9 d2 fa ff ff <0f> ff e9 0f ff ff ff 41 3b 86 d8 00 00 00 0f 84 c2 f3 ff ff 0f
[ 143.238306] ---[ end trace 81f0c82a360b9fb6 ]---
[ 143.238369] XFS (dm-1): metadata I/O error: block 0x2 ("xfs_trans_read_buf_map") error 5 numblks 1
[ 143.238373] XFS (dm-1): xfs_do_force_shutdown(0x1) called from line 315 of file /usr/src/linux-git/fs/xfs/xfs_trans_buf.c. Return address = 0xffffffff9734a15c
[ 143.238378] XFS (dm-1): I/O Error Detected. Shutting down filesystem
[ 143.238378] XFS (dm-1): Please umount the filesystem and rectify the problem(s)
(your patch, compile-fixed, applied on 4.12.14 with offset=6)
Bruno
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