Re: [PATCH v2 05/15] xfs: mount-api - make xfs_parse_param() take context .parse_param() args

From: Eric Sandeen <sandeen@sandeen.net>
To: Ian Kent <raven@themaw.net>, linux-xfs <linux-xfs@vger.kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>,
	David Howells <dhowells@redhat.com>,
	Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [PATCH v2 05/15] xfs: mount-api - make xfs_parse_param() take context .parse_param() args
Date: Mon, 26 Aug 2019 14:32:38 -0500	[thread overview]
Message-ID: <393483c3-1fb4-f225-3372-f6e80cefba71@sandeen.net> (raw)
In-Reply-To: <a6c39432-063e-a619-1691-83134f8fafef@sandeen.net>

On 8/26/19 2:31 PM, Eric Sandeen wrote:
> On 8/26/19 2:19 PM, Eric Sandeen wrote:
>>>  	case Opt_biosize:
>>> -		if (match_kstrtoint(args, 10, &iosize))
>>> +		if (suffix_kstrtoint(param->string, 10, &iosize))
>>>  			return -EINVAL;
>>> -		*iosizelog = ffs(iosize) - 1;
>>> +		ctx->iosizelog = ffs(iosize) - 1;
>>>  		break;
>>>  	case Opt_grpid:
>>> +		if (result.negated)
>>> +			mp->m_flags &= ~XFS_MOUNT_GRPID;
>>> +		else
>>> +			mp->m_flags |= XFS_MOUNT_GRPID;
>>> +		break;
>> Is there any real advantage to this "fsparam_flag_no" / negated stuff?
>> I don't see any other filesystem using it (yet) and I'm not totally convinced
>> that this is any better, more readable, or more efficient than just keeping
>> the "Opt_nogrpid" stuff around.  Not a dealbreaker but just thinking out
>> loud... seems like this interface was a solution in search of a problem?
> 
> Also, at least as of this patch, it seems broken:
> 
> [xfstests-dev]# mount -o noikeep /dev/pmem0p1 /mnt/test
> mount: mount /dev/pmem0p1 on /mnt/test failed: Unknown error 519
> 
> <dmesg shows nothing>
> 
> [xfstests-dev]# mount -o ikeep /dev/pmem0p1 /mnt/test
> mount: wrong fs type, bad option, bad superblock on /dev/pmem0p1,
>        missing codepage or helper program, or other error
> 
>        In some cases useful info is found in syslog - try
>        dmesg | tail or so.
> [xfstests-dev]# dmesg | tail -n 1
> [  282.281557] XFS: Unexpected value for 'ikeep'

and it panics shortly after these failures.

[  378.761698] WARNING: CPU: 8 PID: 12477 at kernel/rcu/tree.c:2498 __call_rcu+0x1e9/0x290
[  378.770633] Modules linked in: macsec tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter intel_rapl_msr intel_rapl_common sunrpc x86_pkg_temp_thermal intel_powerclamp coretemp kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel nd_pmem nd_btt iTCO_wdt intel_cstate ipmi_si iTCO_vendor_support mei_me ipmi_devintf intel_uncore intel_rapl_perf mei ipmi_msghandler wmi nd_e820 libnvdimm pcspkr sg i2c_i801 ioatdma lpc_ich binfmt_misc ip_tables xfs(O) libcrc32c sd_mod mgag200 drm_vram_helper ttm drm_kms_helper syscopyarea igb crc32c_intel sysfillrect sysimgblt isci fb_sys_fops ptp libsas ahci pps_core drm scsi_transport_sas libahci dca i2c_algo_bit libata i2c_core dm_mirror dm_region_hash dm_log dm_mod
[  378.863955] CPU: 8 PID: 12477 Comm: bash Kdump: loaded Tainted: G           O      5.3.0-rc2+ #12
[  378.873860] Hardware name: Intel Corporation LH Pass/SVRBD-ROW_P, BIOS SE5C600.86B.02.01.SP06.050920141054 05/09/2014
[  378.885696] RIP: 0010:__call_rcu+0x1e9/0x290
[  378.890460] Code: 0f 84 8d 00 00 00 48 89 83 b0 00 00 00 48 8b 83 98 00 00 00 48 89 83 a8 00 00 00 e9 b4 fe ff ff e8 2c c8 ff ff e9 5f ff ff ff <0f> 0b 0f 1f 44 00 00 e9 31 fe ff ff 83 fa ff 0f 1f 84 00 00 00 00
[  378.911418] RSP: 0018:ffffc900070a3de0 EFLAGS: 00010206
[  378.917247] RAX: 0000000080000000 RBX: ffff888ffc6eade5 RCX: 0000000000000000
[  378.925210] RDX: 00000000ffffffff RSI: ffffffff81747450 RDI: ffff888ffc6eafbd
[  378.933174] RBP: ffff888ffc6eafbd R08: 0000000000000000 R09: ffff888ffc6eaec5
[  378.941135] R10: ffff88901567c880 R11: ffff889000844a10 R12: ffff888ffc6eafb5
[  378.949098] R13: ffff888103e20750 R14: ffffffff81747450 R15: 0000000000000000
[  378.957062] FS:  00007f08a102b740(0000) GS:ffff88901ea00000(0000) knlGS:0000000000000000
[  378.966092] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  378.972505] CR2: 00007f08a1037000 CR3: 0000000ffc77a004 CR4: 00000000001606e0
[  378.980469] Call Trace:
[  378.983208]  netlink_release+0x2b1/0x540
[  378.987586]  __sock_release+0x3d/0xc0
[  378.991673]  sock_close+0x11/0x20
[  378.995373]  __fput+0xbe/0x250
[  378.998784]  task_work_run+0x88/0xa0
[  379.002775]  exit_to_usermode_loop+0x77/0xc7
[  379.007537]  do_syscall_64+0x1a1/0x1d0
[  379.011721]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  379.017361] RIP: 0033:0x7f08a0714620
[  379.021348] Code: 00 64 c7 00 0d 00 00 00 b8 ff ff ff ff eb 90 b8 ff ff ff ff eb 89 0f 1f 40 00 83 3d 7d c9 2d 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 9e c5 01 00 48 89 04 24
[  379.042303] RSP: 002b:00007ffdef07c748 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
[  379.050752] RAX: 0000000000000000 RBX: 0000000001e0cc70 RCX: 00007f08a0714620
[  379.058715] RDX: 0000000000000000 RSI: 00007ffdef07c790 RDI: 0000000000000003
[  379.066679] RBP: 0000000000000003 R08: 00007ffdef07c6a0 R09: 00007ffdef07c5f0
[  379.074640] R10: 0000000000000008 R11: 0000000000000246 R12: 000000000000001c
[  379.082602] R13: 0000000000000001 R14: 0000000000000002 R15: 00007ffdef07c930
[  379.090565] ---[ end trace 0146f578893eb498 ]---