Linux 4.12 compat: fix super_setup_bdi_name() call #6148

loli10K · 2017-05-20T12:24:15Z

Description

Add a format parameter to super_setup_bdi_name() so we don't create duplicate names in /sys/devices/virtual/bdi which prevents more than one ZFS filesystem from being mounted at a time:

root@debian-8-zfs:~# uname -a
Linux debian-8-zfs 4.12.0-rc1 #1 SMP Sat May 20 12:52:46 CEST 2017 x86_64 GNU/Linux
root@debian-8-zfs:~# ls -l /sys/devices/virtual/bdi/ | grep zfs
drwxr-xr-x 3 root root 0 May 20 13:57 zfs
root@debian-8-zfs:~# zfs create $POOLNAME/fs
filesystem 'testpool/fs' can not be mounted due to error 17
cannot mount 'testpool/fs': Invalid argument
filesystem successfully created, but not mounted
root@debian-8-zfs:~# ls -l /sys/devices/virtual/bdi/ | grep zfs
drwxr-xr-x 3 root root 0 May 20 13:57 zfs
root@debian-8-zfs:~# 
root@debian-8-zfs:~# dmesg
[  150.155657] sysfs: cannot create duplicate filename '/devices/virtual/bdi/zfs'
[  150.155669] ------------[ cut here ]------------
[  150.155673] WARNING: CPU: 1 PID: 2927 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x58/0x70
[  150.155674] Modules linked in: zfs(POE) joydev(E) acpi_cpufreq(E) sg(E) evdev(E) pvpanic(E) tpm_tis(E) virtio_balloon(E) virtio_console(E) serio_raw(E) i2c_piix4(E) tpm_tis_core(E) tpm(E) pcspkr(E) button(E) zunicode(POE) zavl(POE) icp(POE) zcommon(POE) znvpair(POE) spl(OE) usbhid(E) sd_mod(E) sr_mod(E) ata_generic(E) virtio_blk(E) 8139too(E) psmouse(E) ahci(E) libahci(E) ehci_pci(E) uhci_hcd(E) ehci_hcd(E) 8139cp(E) virtio_pci(E) mii(E) virtio_ring(E) usbcore(E) ata_piix(E) virtio(E)
[  150.155692] CPU: 1 PID: 2927 Comm: mount.zfs Tainted: P        W  OE   4.12.0-rc1 #1
[  150.155693] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  150.155694] task: ffff915c839da080 task.stack: ffffba2c43cb8000
[  150.155695] RIP: 0010:sysfs_warn_dup+0x58/0x70
[  150.155696] RSP: 0018:ffffba2c43cbba98 EFLAGS: 00010282
[  150.155697] RAX: 0000000000000042 RBX: ffff915c8f83a000 RCX: 0000000000000000
[  150.155698] RDX: 0000000000000000 RSI: ffff915c9fc4e048 RDI: ffff915c9fc4e048
[  150.155699] RBP: ffffba2c43cbbab0 R08: 0000000000000001 R09: 0000000000000381
[  150.155699] R10: ffff915c9a64a700 R11: 0000000000000381 R12: ffff915c926c6f20
[  150.155700] R13: ffff915bb03161e0 R14: ffff915c8e684c18 R15: ffff915c8d097018
[  150.155701] FS:  00007ff575485780(0000) GS:ffff915c9fc40000(0000) knlGS:0000000000000000
[  150.155702] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  150.155703] CR2: 00007ff5749cfe7f CR3: 000000010d560000 CR4: 00000000000006e0
[  150.155706] Call Trace:
[  150.155708]  sysfs_create_dir_ns+0x77/0x90
[  150.155711]  kobject_add_internal+0xc0/0x2d0
[  150.155712]  kobject_add+0x71/0xd0
[  150.155715]  ? refcount_inc+0x9/0x30
[  150.155717]  device_add+0x117/0x670
[  150.155718]  device_create_groups_vargs+0xe0/0xf0
[  150.155720]  device_create_vargs+0x16/0x20
[  150.155722]  bdi_register_va.part.11+0x2e/0x1b0
[  150.155723]  bdi_register_va+0x1b/0x20
[  150.155725]  super_setup_bdi_name+0x87/0xf0
[  150.155765]  ? dsl_prop_get+0x7a/0xa0 [zfs]
[  150.155795]  zfs_domount+0x121/0x440 [zfs]
[  150.155825]  zpl_fill_super+0x40/0x110 [zfs]
[  150.155853]  ? zpl_statfs+0x110/0x110 [zfs]
[  150.155855]  mount_nodev+0x4e/0xa0
[  150.155882]  zpl_mount+0x34/0x50 [zfs]
[  150.155884]  mount_fs+0x38/0x150
[  150.155886]  vfs_kern_mount+0x64/0x130
[  150.155887]  do_mount+0x1e5/0xcd0
[  150.155889]  ? _copy_from_user+0x33/0x70
[  150.155890]  SyS_mount+0x94/0xd0
[  150.155892]  entry_SYSCALL_64_fastpath+0x1e/0xa9
[  150.155893] RIP: 0033:0x7ff573aa9fda
[  150.155894] RSP: 002b:00007ffec9519fa8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
[  150.155895] RAX: ffffffffffffffda RBX: 000000000153c060 RCX: 00007ff573aa9fda
[  150.155896] RDX: 00000000004022e6 RSI: 00007ffec951e080 RDI: 00007ffec951fee0
[  150.155896] RBP: 00007ffec9519f90 R08: 00007ffec951b080 R09: 0000000001543650
[  150.155897] R10: 0000000001000000 R11: 0000000000000202 R12: 00007ffec951b080
[  150.155898] R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000001
[  150.155898] Code: 48 89 c3 74 12 b9 00 10 00 00 48 89 c2 31 f6 4c 89 ef e8 5c c8 ff ff 4c 89 e2 48 89 de 48 c7 c7 68 29 ab 88 31 c0 e8 7f 2c ee ff <0f> ff 48 89 df e8 9e 1a f5 ff 5b 41 5c 41 5d 5d c3 0f 1f 80 00 
[  150.155916] ---[ end trace a2337445839d0b0e ]---
[  150.155918] kobject_add_internal failed for zfs with -EEXIST, don't try to register things with the same name in the same directory.
[  150.155925] ------------[ cut here ]------------
[  150.155928] WARNING: CPU: 1 PID: 2927 at lib/kobject.c:240 kobject_add_internal+0x284/0x2d0
[  150.155928] Modules linked in: zfs(POE) joydev(E) acpi_cpufreq(E) sg(E) evdev(E) pvpanic(E) tpm_tis(E) virtio_balloon(E) virtio_console(E) serio_raw(E) i2c_piix4(E) tpm_tis_core(E) tpm(E) pcspkr(E) button(E) zunicode(POE) zavl(POE) icp(POE) zcommon(POE) znvpair(POE) spl(OE) usbhid(E) sd_mod(E) sr_mod(E) ata_generic(E) virtio_blk(E) 8139too(E) psmouse(E) ahci(E) libahci(E) ehci_pci(E) uhci_hcd(E) ehci_hcd(E) 8139cp(E) virtio_pci(E) mii(E) virtio_ring(E) usbcore(E) ata_piix(E) virtio(E)
[  150.155942] CPU: 1 PID: 2927 Comm: mount.zfs Tainted: P        W  OE   4.12.0-rc1 #1
[  150.155942] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  150.155943] task: ffff915c839da080 task.stack: ffffba2c43cb8000
[  150.155944] RIP: 0010:kobject_add_internal+0x284/0x2d0
[  150.155945] RSP: 0018:ffffba2c43cbbae8 EFLAGS: 00010282
[  150.155946] RAX: 0000000000000078 RBX: ffff915c8d097010 RCX: 0000000000000006
[  150.155946] RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff915c9fc4e040
[  150.155947] RBP: ffffba2c43cbbb18 R08: 0000000000000001 R09: 00000000000003b2
[  150.155948] R10: ffff915c9a64a700 R11: 00000000000003b2 R12: 00000000ffffffef
[  150.155948] R13: ffff915bb02f0a80 R14: ffff915c8e684c18 R15: ffff915c8d097018
[  150.155949] FS:  00007ff575485780(0000) GS:ffff915c9fc40000(0000) knlGS:0000000000000000
[  150.155950] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  150.155951] CR2: 00007ff5749cfe7f CR3: 000000010d560000 CR4: 00000000000006e0
[  150.155953] Call Trace:
[  150.155954]  kobject_add+0x71/0xd0
[  150.155956]  ? refcount_inc+0x9/0x30
[  150.155957]  device_add+0x117/0x670
[  150.155959]  device_create_groups_vargs+0xe0/0xf0
[  150.155960]  device_create_vargs+0x16/0x20
[  150.155961]  bdi_register_va.part.11+0x2e/0x1b0
[  150.155962]  bdi_register_va+0x1b/0x20
[  150.155964]  super_setup_bdi_name+0x87/0xf0
[  150.155989]  ? dsl_prop_get+0x7a/0xa0 [zfs]
[  150.156018]  zfs_domount+0x121/0x440 [zfs]
[  150.156046]  zpl_fill_super+0x40/0x110 [zfs]
[  150.156073]  ? zpl_statfs+0x110/0x110 [zfs]
[  150.156075]  mount_nodev+0x4e/0xa0
[  150.156102]  zpl_mount+0x34/0x50 [zfs]
[  150.156104]  mount_fs+0x38/0x150
[  150.156105]  vfs_kern_mount+0x64/0x130
[  150.156106]  do_mount+0x1e5/0xcd0
[  150.156108]  ? _copy_from_user+0x33/0x70
[  150.156109]  SyS_mount+0x94/0xd0
[  150.156111]  entry_SYSCALL_64_fastpath+0x1e/0xa9
[  150.156111] RIP: 0033:0x7ff573aa9fda
[  150.156112] RSP: 002b:00007ffec9519fa8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
[  150.156113] RAX: ffffffffffffffda RBX: 000000000153c060 RCX: 00007ff573aa9fda
[  150.156114] RDX: 00000000004022e6 RSI: 00007ffec951e080 RDI: 00007ffec951fee0
[  150.156114] RBP: 00007ffec9519f90 R08: 00007ffec951b080 R09: 0000000001543650
[  150.156115] R10: 0000000001000000 R11: 0000000000000202 R12: 00007ffec951b080
[  150.156116] R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000001
[  150.156116] Code: 7b 20 49 89 c5 48 85 ff 0f 84 3d fe ff ff e9 e4 fd ff ff 48 8b 13 48 c7 c6 00 bd 89 88 48 c7 c7 08 97 af 88 31 c0 e8 03 66 cc ff <0f> ff e9 8f fe ff ff 0f 0b 0f 0b 0f 0b 0f ff eb 9a 0f ff eb 8d 
[  150.156134] ---[ end trace a2337445839d0b0f ]---

Motivation and Context

Fix #6147

How Has This Been Tested?

Manually tested on linux-4.12-rc1

Types of changes

Bug fix (non-breaking change which fixes an issue)
New feature (non-breaking change which adds functionality)
Performance enhancement (non-breaking change which improves efficiency)
Code cleanup (non-breaking change which makes code smaller or more readable)
Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

My code follows the ZFS on Linux code style requirements.
I have updated the documentation accordingly.
I have read the CONTRIBUTING document.
I have added tests to cover my changes.
All new and existing tests passed.
All commit messages are properly formatted and contain Signed-off-by.
Change has been approved by a ZFS on Linux member.

mention-bot · 2017-05-20T12:24:17Z

@loli10K, thanks for your PR! By analyzing the history of the files in this pull request, we identified @maxximino, @behlendorf and @ahrens to be potential reviewers.

tuxoko · 2017-05-22T18:02:13Z

include/linux/vfs_compat.h

+
+	sprintf(tmp, "%.28s%s", name, "-%d");
+	return super_setup_bdi_name(sb, tmp,
+	    atomic_long_inc_return(&zfs_bdi_seq));


There's no reason to use two format functions, fold sprintf into super_setup_bdi_name

@tuxoko did you mean something like the following?

super_setup_bdi_name(sb, "%.28s-%ld", name, atomic_long_inc_return(&zfs_bdi_seq));

I basically just copy/pasted the code from https://github.com/zfsonlinux/zfs/blob/5547c2f1bf49802835fd6c52f15115ba344a2a8b/include/linux/vfs_compat.h#L85, should we update that too?

Yeah, we should do that. This code is ugly and kinda dangerous, in that if the name is user supplied, then you're using a user supplied format string.

Provide a format parameter to super_setup_bdi_name() so we don't create duplicate names in '/devices/virtual/bdi' sysfs namespace which would prevent us from mounting more than one ZFS filesystem at a time. Signed-off-by: loli10K <[email protected]>

arachnist mentioned this pull request May 20, 2017

Can mount only one filesystem at a time on kernel 4.12.0-rc1 #6147

Closed

loli10K force-pushed the issue-6147 branch from 881a7b8 to 11a370a Compare May 22, 2017 17:44

tuxoko suggested changes May 22, 2017

View reviewed changes

loli10K force-pushed the issue-6147 branch from 11a370a to f91868a Compare May 23, 2017 19:21

tuxoko approved these changes May 23, 2017

View reviewed changes

behlendorf approved these changes May 25, 2017

View reviewed changes

behlendorf merged commit 3e6c943 into openzfs:master May 25, 2017

loli10K deleted the issue-6147 branch May 26, 2017 04:36

loli10K restored the issue-6147 branch November 1, 2018 15:41

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Linux 4.12 compat: fix super_setup_bdi_name() call #6148

Linux 4.12 compat: fix super_setup_bdi_name() call #6148

loli10K commented May 20, 2017

mention-bot commented May 20, 2017

tuxoko May 22, 2017

loli10K May 23, 2017

tuxoko May 23, 2017

Linux 4.12 compat: fix super_setup_bdi_name() call #6148

Linux 4.12 compat: fix super_setup_bdi_name() call #6148

Conversation

loli10K commented May 20, 2017

Description

Motivation and Context

How Has This Been Tested?

Types of changes

Checklist:

mention-bot commented May 20, 2017

tuxoko May 22, 2017

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loli10K May 23, 2017

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tuxoko May 23, 2017

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