* fs: panic in mnt_set_mountpoint
@ 2014-08-18 11:09 Jonas Jensen
2014-08-18 12:08 ` Ming Lei
2014-08-18 15:33 ` Thierry Reding
0 siblings, 2 replies; 8+ messages in thread
From: Jonas Jensen @ 2014-08-18 11:09 UTC (permalink / raw)
To: linux-fsdevel, viro; +Cc: linux-kernel
Hi,
I've run into a kernel panic [1] in next-20140818 you might find interesting.
It surprised me because there was never an error in next-20140815, I
did a search for related panics but it came up empty.
The board boots fine after applying the following:
diff --git a/fs/namespace.c b/fs/namespace.c
index 1a2bbef..b408a9d 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -746,7 +746,7 @@ static void put_mountpoint(struct mountpoint *mp)
{
if (!--mp->m_count) {
struct dentry *dentry = mp->m_dentry;
- BUG_ON(!hlist_empty(&mp->m_list));
+/* BUG_ON(!hlist_empty(&mp->m_list));*/
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_MOUNTED;
spin_unlock(&dentry->d_lock);
@@ -810,7 +810,7 @@ void mnt_set_mountpoint(struct mount *mnt,
child_mnt->mnt_mountpoint = dget(mp->m_dentry);
child_mnt->mnt_parent = mnt;
child_mnt->mnt_mp = mp;
- hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);
+/* hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);*/
}
[1]
Uncompressing Linux... done, booting the kernel.
[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Linux version 3.17.0-rc1-next-20140818+ (i@Ildjarn) (gcc
version 4.9.0 (crosstool-NG 1.19.0) ) #2691 PREEMPT Mon Aug 18
10:58:16 CEST 2014
[ 0.000000] CPU: FA526 [66015261] revision 1 (ARMv4), cr=0000397f
[ 0.000000] CPU: VIVT data cache, VIVT instruction cache
[ 0.000000] Machine model: MOXA UC-7112-LX
[ 0.000000] bootconsole [earlycon0] enabled
[ 0.000000] Memory policy: Data cache writeback
[ 0.000000] On node 0 totalpages: 8192
[ 0.000000] free_area_init_node: node 0, pgdat c035cfb4, node_mem_map c1fba000
[ 0.000000] Normal zone: 64 pages used for memmap
[ 0.000000] Normal zone: 0 pages reserved
[ 0.000000] Normal zone: 8192 pages, LIFO batch:0
[ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[ 0.000000] pcpu-alloc: [0] 0
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on.
Total pages: 8128
[ 0.000000] Kernel command line: console=ttyS0,115200n8 earlyprintk
root=/dev/mmcblk0p1 rw rootwait debug
[ 0.000000] PID hash table entries: 128 (order: -3, 512 bytes)
[ 0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
[ 0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
[ 0.000000] Memory: 28852K/32768K available (2718K kernel code, 93K
rwdata, 484K rodata, 115K init, 126K bss, 3916K reserved)
[ 0.000000] Virtual kernel memory layout:
[ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB)
[ 0.000000] fixmap : 0xffc00000 - 0xffe00000 (2048 kB)
[ 0.000000] vmalloc : 0xc2800000 - 0xff000000 ( 968 MB)
[ 0.000000] lowmem : 0xc0000000 - 0xc2000000 ( 32 MB)
[ 0.000000] .text : 0xc0008000 - 0xc0328aec (3203 kB)
[ 0.000000] .init : 0xc0329000 - 0xc0345ddc ( 116 kB)
[ 0.000000] .data : 0xc0346000 - 0xc035d700 ( 94 kB)
[ 0.000000] .bss : 0xc035d700 - 0xc037cf24 ( 127 kB)
[ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[ 0.000000] Preemptible hierarchical RCU implementation.
[ 0.000000] NR_IRQS:16 nr_irqs:16 16
[ 0.000000] sched_clock: 32 bits at 100 Hz, resolution 10000000ns,
wraps every 21474836480000000ns
[ 0.010000] Calibrating delay loop... 147.86 BogoMIPS (lpj=739328)
[ 0.090000] pid_max: default: 4096 minimum: 301
[ 0.090000] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.100000] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.110000] CPU: Testing write buffer coherency: ok
[ 0.120000] Setting up static identity map for 0x296938 - 0x296980
[ 0.140000] Unhandled fault: alignment exception (0x801) at 0x00000003
[ 0.140000] Internal error: : 801 [#1] PREEMPT ARM
[ 0.140000] CPU: 0 PID: 11 Comm: kdevtmpfs Not tainted
3.17.0-rc1-next-20140818+ #2691
[ 0.140000] task: c184a360 ti: c1850000 task.ti: c1850000
[ 0.140000] PC is at mnt_set_mountpoint+0x8c/0x9c
[ 0.140000] LR is at mnt_set_mountpoint+0x70/0x9c
[ 0.140000] pc : [<c00a8978>] lr : [<c00a895c>] psr: a0000053
[ 0.140000] sp : c1851e18 ip : 00000001 fp : 00000000
[ 0.140000] r10: c1802ae0 r9 : c1802ba0 r8 : 00000000
[ 0.140000] r7 : c1402000 r6 : c1842240 r5 : c1842300 r4 : c1802ba0
[ 0.140000] r3 : ffffffff r2 : c184237c r1 : c1802ba0 r0 : c1402054
[ 0.140000] Flags: NzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel
[ 0.140000] Control: 0000397f Table: 00004000 DAC: 00000017
[ 0.140000] Process kdevtmpfs (pid: 11, stack limit = 0xc18501c0)
[ 0.140000] Stack: (0xc1851e18 to 0xc1852000)
[ 0.140000] 1e00: 0000000dc1842300
[ 0.140000] 1e20:
c1842300c1802ba0c1842240c00a9464c184230000000000c1802ba0c1842300
[ 0.140000] 1e40:
00000020c1802ba0c1851e70c1802b00c1852000c00a96a400000000c0354690
[ 0.140000] 1e60:
00000020c1842310c034db48c00aad54c1842250c1402000c1851ec400000000
[ 0.140000] 1e80:
00000000000000000000000000000000c181100000008000c02fdfb900000000
[ 0.140000] 1ea0:
000000000000000000000000c00aafccc1852000c1802aa000020200c1802ae0
[ 0.140000] 1ec0:
c1802b00c185200000000000c182bf5cc1851f06c182bf5cc0172950c017299c
[ 0.140000] 1ee0:
c1851f06ffffffffffffffffffffffffffffffffffffffffffffffffffffffff
[ 0.140000] 1f00:
ffffffff6f6da000303d65640035353700000000c0029ac40000000000000002
[ 0.140000] 1f20:
c182a000c182a01cc184a3600000001700000000c184a360c1850000c1828000
[ 0.140000] 1f40:
c1851f6cc029363c00000000c1802aa000000000c182bf5cc017295000000000
[ 0.140000] 1f60:
000000000000000000000000c0028becffffffff00000000ffffffffc182bf5c
[ 0.140000] 1f80:
00000000c1851f84c1851f8400000000c1851f90c1851f90c1851facc1802aa0
[ 0.140000] 1fa0:
c0028b280000000000000000c000925000000000000000000000000000000000
[ 0.140000] 1fc0:
0000000000000000000000000000000000000000000000000000000000000000
[ 0.140000] 1fe0:
000000000000000000000000000000000000001300000000ffffffffffffffff
[ 0.140000] [<c00a8978>] (mnt_set_mountpoint) from [<c00a9464>]
(attach_recursive_mnt+0x114/0x22c)
[ 0.140000] [<c00a9464>] (attach_recursive_mnt) from [<c00a96a4>]
(do_add_mount+0xb8/0xd4)
[ 0.140000] [<c00a96a4>] (do_add_mount) from [<c00aad54>] (do_mount+0xa08/0xa48)
[ 0.140000] [<c00aad54>] (do_mount) from [<c00aafcc>] (SyS_mount+0x84/0xb8)
[ 0.140000] [<c00aafcc>] (SyS_mount) from [<c017299c>] (devtmpfsd+0x4c/0x2fc)
[ 0.140000] [<c017299c>] (devtmpfsd) from [<c0028bec>] (kthread+0xc4/0xd8)
[ 0.140000] [<c0028bec>] (kthread) from [<c0009250>] (ret_from_fork+0x14/0x24)
[ 0.140000] Code: e594300ce285207ce3530000e585307c (15832004)
[ 0.140000] ---[ end trace 1298010f773134bc ]---
[ 0.140000] Kernel panic - not syncing: Fatal exception
[ 0.140000] Rebooting in 10 seconds..Reboot failed -- System halted
Jonas
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: fs: panic in mnt_set_mountpoint
2014-08-18 11:09 fs: panic in mnt_set_mountpoint Jonas Jensen
@ 2014-08-18 12:08 ` Ming Lei
2014-08-18 15:33 ` Thierry Reding
1 sibling, 0 replies; 8+ messages in thread
From: Ming Lei @ 2014-08-18 12:08 UTC (permalink / raw)
To: Jonas Jensen; +Cc: Linux FS Devel, Al Viro, linux-kernel
On Mon, Aug 18, 2014 at 7:09 PM, Jonas Jensen <jonas.jensen@gmail.com> wrote:
> Hi,
>
> I've run into a kernel panic [1] in next-20140818 you might find interesting.
>
> It surprised me because there was never an error in next-20140815, I
> did a search for related panics but it came up empty.
>
> The board boots fine after applying the following:
>
> diff --git a/fs/namespace.c b/fs/namespace.c
> index 1a2bbef..b408a9d 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -746,7 +746,7 @@ static void put_mountpoint(struct mountpoint *mp)
> {
> if (!--mp->m_count) {
> struct dentry *dentry = mp->m_dentry;
> - BUG_ON(!hlist_empty(&mp->m_list));
> +/* BUG_ON(!hlist_empty(&mp->m_list));*/
> spin_lock(&dentry->d_lock);
> dentry->d_flags &= ~DCACHE_MOUNTED;
> spin_unlock(&dentry->d_lock);
> @@ -810,7 +810,7 @@ void mnt_set_mountpoint(struct mount *mnt,
> child_mnt->mnt_mountpoint = dget(mp->m_dentry);
> child_mnt->mnt_parent = mnt;
> child_mnt->mnt_mp = mp;
> - hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);
> +/* hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);*/
> }
>
>
> [1]
> Uncompressing Linux... done, booting the kernel.
> [ 0.000000] Booting Linux on physical CPU 0x0
> [ 0.000000] Linux version 3.17.0-rc1-next-20140818+ (i@Ildjarn) (gcc
> version 4.9.0 (crosstool-NG 1.19.0) ) #2691 PREEMPT Mon Aug 18
> 10:58:16 CEST 2014
> [ 0.000000] CPU: FA526 [66015261] revision 1 (ARMv4), cr=0000397f
> [ 0.000000] CPU: VIVT data cache, VIVT instruction cache
> [ 0.000000] Machine model: MOXA UC-7112-LX
> [ 0.000000] bootconsole [earlycon0] enabled
> [ 0.000000] Memory policy: Data cache writeback
> [ 0.000000] On node 0 totalpages: 8192
> [ 0.000000] free_area_init_node: node 0, pgdat c035cfb4, node_mem_map c1fba000
> [ 0.000000] Normal zone: 64 pages used for memmap
> [ 0.000000] Normal zone: 0 pages reserved
> [ 0.000000] Normal zone: 8192 pages, LIFO batch:0
> [ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
> [ 0.000000] pcpu-alloc: [0] 0
> [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on.
> Total pages: 8128
> [ 0.000000] Kernel command line: console=ttyS0,115200n8 earlyprintk
> root=/dev/mmcblk0p1 rw rootwait debug
> [ 0.000000] PID hash table entries: 128 (order: -3, 512 bytes)
> [ 0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
> [ 0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
> [ 0.000000] Memory: 28852K/32768K available (2718K kernel code, 93K
> rwdata, 484K rodata, 115K init, 126K bss, 3916K reserved)
> [ 0.000000] Virtual kernel memory layout:
> [ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB)
> [ 0.000000] fixmap : 0xffc00000 - 0xffe00000 (2048 kB)
> [ 0.000000] vmalloc : 0xc2800000 - 0xff000000 ( 968 MB)
> [ 0.000000] lowmem : 0xc0000000 - 0xc2000000 ( 32 MB)
> [ 0.000000] .text : 0xc0008000 - 0xc0328aec (3203 kB)
> [ 0.000000] .init : 0xc0329000 - 0xc0345ddc ( 116 kB)
> [ 0.000000] .data : 0xc0346000 - 0xc035d700 ( 94 kB)
> [ 0.000000] .bss : 0xc035d700 - 0xc037cf24 ( 127 kB)
> [ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
> [ 0.000000] Preemptible hierarchical RCU implementation.
> [ 0.000000] NR_IRQS:16 nr_irqs:16 16
> [ 0.000000] sched_clock: 32 bits at 100 Hz, resolution 10000000ns,
> wraps every 21474836480000000ns
> [ 0.010000] Calibrating delay loop... 147.86 BogoMIPS (lpj=739328)
> [ 0.090000] pid_max: default: 4096 minimum: 301
> [ 0.090000] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
> [ 0.100000] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
> [ 0.110000] CPU: Testing write buffer coherency: ok
> [ 0.120000] Setting up static identity map for 0x296938 - 0x296980
> [ 0.140000] Unhandled fault: alignment exception (0x801) at 0x00000003
> [ 0.140000] Internal error: : 801 [#1] PREEMPT ARM
> [ 0.140000] CPU: 0 PID: 11 Comm: kdevtmpfs Not tainted
> 3.17.0-rc1-next-20140818+ #2691
> [ 0.140000] task: c184a360 ti: c1850000 task.ti: c1850000
> [ 0.140000] PC is at mnt_set_mountpoint+0x8c/0x9c
> [ 0.140000] LR is at mnt_set_mountpoint+0x70/0x9c
> [ 0.140000] pc : [<c00a8978>] lr : [<c00a895c>] psr: a0000053
> [ 0.140000] sp : c1851e18 ip : 00000001 fp : 00000000
> [ 0.140000] r10: c1802ae0 r9 : c1802ba0 r8 : 00000000
> [ 0.140000] r7 : c1402000 r6 : c1842240 r5 : c1842300 r4 : c1802ba0
> [ 0.140000] r3 : ffffffff r2 : c184237c r1 : c1802ba0 r0 : c1402054
> [ 0.140000] Flags: NzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel
> [ 0.140000] Control: 0000397f Table: 00004000 DAC: 00000017
> [ 0.140000] Process kdevtmpfs (pid: 11, stack limit = 0xc18501c0)
> [ 0.140000] Stack: (0xc1851e18 to 0xc1852000)
> [ 0.140000] 1e00: 0000000dc1842300
> [ 0.140000] 1e20:
> c1842300c1802ba0c1842240c00a9464c184230000000000c1802ba0c1842300
> [ 0.140000] 1e40:
> 00000020c1802ba0c1851e70c1802b00c1852000c00a96a400000000c0354690
> [ 0.140000] 1e60:
> 00000020c1842310c034db48c00aad54c1842250c1402000c1851ec400000000
> [ 0.140000] 1e80:
> 00000000000000000000000000000000c181100000008000c02fdfb900000000
> [ 0.140000] 1ea0:
> 000000000000000000000000c00aafccc1852000c1802aa000020200c1802ae0
> [ 0.140000] 1ec0:
> c1802b00c185200000000000c182bf5cc1851f06c182bf5cc0172950c017299c
> [ 0.140000] 1ee0:
> c1851f06ffffffffffffffffffffffffffffffffffffffffffffffffffffffff
> [ 0.140000] 1f00:
> ffffffff6f6da000303d65640035353700000000c0029ac40000000000000002
> [ 0.140000] 1f20:
> c182a000c182a01cc184a3600000001700000000c184a360c1850000c1828000
> [ 0.140000] 1f40:
> c1851f6cc029363c00000000c1802aa000000000c182bf5cc017295000000000
> [ 0.140000] 1f60:
> 000000000000000000000000c0028becffffffff00000000ffffffffc182bf5c
> [ 0.140000] 1f80:
> 00000000c1851f84c1851f8400000000c1851f90c1851f90c1851facc1802aa0
> [ 0.140000] 1fa0:
> c0028b280000000000000000c000925000000000000000000000000000000000
> [ 0.140000] 1fc0:
> 0000000000000000000000000000000000000000000000000000000000000000
> [ 0.140000] 1fe0:
> 000000000000000000000000000000000000001300000000ffffffffffffffff
> [ 0.140000] [<c00a8978>] (mnt_set_mountpoint) from [<c00a9464>]
> (attach_recursive_mnt+0x114/0x22c)
> [ 0.140000] [<c00a9464>] (attach_recursive_mnt) from [<c00a96a4>]
> (do_add_mount+0xb8/0xd4)
> [ 0.140000] [<c00a96a4>] (do_add_mount) from [<c00aad54>] (do_mount+0xa08/0xa48)
> [ 0.140000] [<c00aad54>] (do_mount) from [<c00aafcc>] (SyS_mount+0x84/0xb8)
> [ 0.140000] [<c00aafcc>] (SyS_mount) from [<c017299c>] (devtmpfsd+0x4c/0x2fc)
> [ 0.140000] [<c017299c>] (devtmpfsd) from [<c0028bec>] (kthread+0xc4/0xd8)
> [ 0.140000] [<c0028bec>] (kthread) from [<c0009250>] (ret_from_fork+0x14/0x24)
> [ 0.140000] Code: e594300ce285207ce3530000e585307c (15832004)
> [ 0.140000] ---[ end trace 1298010f773134bc ]---
> [ 0.140000] Kernel panic - not syncing: Fatal exception
> [ 0.140000] Rebooting in 10 seconds..Reboot failed -- System halted
+1
Thanks,
--
Ming Lei
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: fs: panic in mnt_set_mountpoint
2014-08-18 11:09 fs: panic in mnt_set_mountpoint Jonas Jensen
2014-08-18 12:08 ` Ming Lei
@ 2014-08-18 15:33 ` Thierry Reding
2014-08-18 19:33 ` Kevin Hilman
` (2 more replies)
1 sibling, 3 replies; 8+ messages in thread
From: Thierry Reding @ 2014-08-18 15:33 UTC (permalink / raw)
To: Jonas Jensen; +Cc: linux-fsdevel, viro, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 4718 bytes --]
On Mon, Aug 18, 2014 at 01:09:24PM +0200, Jonas Jensen wrote:
> Hi,
>
> I've run into a kernel panic [1] in next-20140818 you might find interesting.
>
> It surprised me because there was never an error in next-20140815, I
> did a search for related panics but it came up empty.
>
> The board boots fine after applying the following:
>
> diff --git a/fs/namespace.c b/fs/namespace.c
> index 1a2bbef..b408a9d 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -746,7 +746,7 @@ static void put_mountpoint(struct mountpoint *mp)
> {
> if (!--mp->m_count) {
> struct dentry *dentry = mp->m_dentry;
> - BUG_ON(!hlist_empty(&mp->m_list));
> +/* BUG_ON(!hlist_empty(&mp->m_list));*/
> spin_lock(&dentry->d_lock);
> dentry->d_flags &= ~DCACHE_MOUNTED;
> spin_unlock(&dentry->d_lock);
> @@ -810,7 +810,7 @@ void mnt_set_mountpoint(struct mount *mnt,
> child_mnt->mnt_mountpoint = dget(mp->m_dentry);
> child_mnt->mnt_parent = mnt;
> child_mnt->mnt_mp = mp;
> - hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);
> +/* hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);*/
> }
>
>
> [1]
> Uncompressing Linux... done, booting the kernel.
> [ 0.000000] Booting Linux on physical CPU 0x0
> [ 0.000000] Linux version 3.17.0-rc1-next-20140818+ (i@Ildjarn) (gcc
> version 4.9.0 (crosstool-NG 1.19.0) ) #2691 PREEMPT Mon Aug 18
> 10:58:16 CEST 2014
> [ 0.000000] CPU: FA526 [66015261] revision 1 (ARMv4), cr=0000397f
> [ 0.000000] CPU: VIVT data cache, VIVT instruction cache
> [ 0.000000] Machine model: MOXA UC-7112-LX
> [ 0.000000] bootconsole [earlycon0] enabled
> [ 0.000000] Memory policy: Data cache writeback
> [ 0.000000] On node 0 totalpages: 8192
> [ 0.000000] free_area_init_node: node 0, pgdat c035cfb4, node_mem_map c1fba000
> [ 0.000000] Normal zone: 64 pages used for memmap
> [ 0.000000] Normal zone: 0 pages reserved
> [ 0.000000] Normal zone: 8192 pages, LIFO batch:0
> [ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
> [ 0.000000] pcpu-alloc: [0] 0
> [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on.
> Total pages: 8128
> [ 0.000000] Kernel command line: console=ttyS0,115200n8 earlyprintk
> root=/dev/mmcblk0p1 rw rootwait debug
> [ 0.000000] PID hash table entries: 128 (order: -3, 512 bytes)
> [ 0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
> [ 0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
> [ 0.000000] Memory: 28852K/32768K available (2718K kernel code, 93K
> rwdata, 484K rodata, 115K init, 126K bss, 3916K reserved)
> [ 0.000000] Virtual kernel memory layout:
> [ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB)
> [ 0.000000] fixmap : 0xffc00000 - 0xffe00000 (2048 kB)
> [ 0.000000] vmalloc : 0xc2800000 - 0xff000000 ( 968 MB)
> [ 0.000000] lowmem : 0xc0000000 - 0xc2000000 ( 32 MB)
> [ 0.000000] .text : 0xc0008000 - 0xc0328aec (3203 kB)
> [ 0.000000] .init : 0xc0329000 - 0xc0345ddc ( 116 kB)
> [ 0.000000] .data : 0xc0346000 - 0xc035d700 ( 94 kB)
> [ 0.000000] .bss : 0xc035d700 - 0xc037cf24 ( 127 kB)
> [ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
> [ 0.000000] Preemptible hierarchical RCU implementation.
> [ 0.000000] NR_IRQS:16 nr_irqs:16 16
> [ 0.000000] sched_clock: 32 bits at 100 Hz, resolution 10000000ns,
> wraps every 21474836480000000ns
> [ 0.010000] Calibrating delay loop... 147.86 BogoMIPS (lpj=739328)
> [ 0.090000] pid_max: default: 4096 minimum: 301
> [ 0.090000] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
> [ 0.100000] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
> [ 0.110000] CPU: Testing write buffer coherency: ok
> [ 0.120000] Setting up static identity map for 0x296938 - 0x296980
> [ 0.140000] Unhandled fault: alignment exception (0x801) at 0x00000003
I've been seeing the same crash starting with next-20140818. I have slab
allocation debugging enabled and the above unhandled fault is apparently
caused by in-use poisoning:
[ 0.301383] Unable to handle kernel paging request at virtual address 5a5a5a5e
The below patch works "fixes" it for me, though I have no idea why it's
needed all of a sudden.
Thierry
diff --git a/fs/namespace.c b/fs/namespace.c
index 4246696dc678..a6815027f225 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -736,6 +736,7 @@ static struct mountpoint *new_mountpoint(struct dentry *dentry)
return ERR_PTR(ret);
}
+ INIT_HLIST_HEAD(&mp->m_list);
mp->m_dentry = dentry;
mp->m_count = 1;
hlist_add_head(&mp->m_hash, chain);
[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: fs: panic in mnt_set_mountpoint
2014-08-18 15:33 ` Thierry Reding
@ 2014-08-18 19:33 ` Kevin Hilman
2014-08-19 2:43 ` [PATCH] fs: Initialize mountpoint list head in new_mountpoint() Murilo Opsfelder Araujo
2014-08-20 12:35 ` fs: panic in mnt_set_mountpoint Jonas Jensen
2 siblings, 0 replies; 8+ messages in thread
From: Kevin Hilman @ 2014-08-18 19:33 UTC (permalink / raw)
To: Thierry Reding; +Cc: Jonas Jensen, linux-fsdevel, viro, linux-kernel
On Mon, Aug 18, 2014 at 8:33 AM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Mon, Aug 18, 2014 at 01:09:24PM +0200, Jonas Jensen wrote:
>> Hi,
>>
>> I've run into a kernel panic [1] in next-20140818 you might find interesting.
>>
>> It surprised me because there was never an error in next-20140815, I
>> did a search for related panics but it came up empty.
>>
>> The board boots fine after applying the following:
>>
>> diff --git a/fs/namespace.c b/fs/namespace.c
>> index 1a2bbef..b408a9d 100644
>> --- a/fs/namespace.c
>> +++ b/fs/namespace.c
>> @@ -746,7 +746,7 @@ static void put_mountpoint(struct mountpoint *mp)
>> {
>> if (!--mp->m_count) {
>> struct dentry *dentry = mp->m_dentry;
>> - BUG_ON(!hlist_empty(&mp->m_list));
>> +/* BUG_ON(!hlist_empty(&mp->m_list));*/
>> spin_lock(&dentry->d_lock);
>> dentry->d_flags &= ~DCACHE_MOUNTED;
>> spin_unlock(&dentry->d_lock);
>> @@ -810,7 +810,7 @@ void mnt_set_mountpoint(struct mount *mnt,
>> child_mnt->mnt_mountpoint = dget(mp->m_dentry);
>> child_mnt->mnt_parent = mnt;
>> child_mnt->mnt_mp = mp;
>> - hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);
>> +/* hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);*/
>> }
>>
>>
>> [1]
>> Uncompressing Linux... done, booting the kernel.
>> [ 0.000000] Booting Linux on physical CPU 0x0
>> [ 0.000000] Linux version 3.17.0-rc1-next-20140818+ (i@Ildjarn) (gcc
>> version 4.9.0 (crosstool-NG 1.19.0) ) #2691 PREEMPT Mon Aug 18
>> 10:58:16 CEST 2014
>> [ 0.000000] CPU: FA526 [66015261] revision 1 (ARMv4), cr=0000397f
>> [ 0.000000] CPU: VIVT data cache, VIVT instruction cache
>> [ 0.000000] Machine model: MOXA UC-7112-LX
>> [ 0.000000] bootconsole [earlycon0] enabled
>> [ 0.000000] Memory policy: Data cache writeback
>> [ 0.000000] On node 0 totalpages: 8192
>> [ 0.000000] free_area_init_node: node 0, pgdat c035cfb4, node_mem_map c1fba000
>> [ 0.000000] Normal zone: 64 pages used for memmap
>> [ 0.000000] Normal zone: 0 pages reserved
>> [ 0.000000] Normal zone: 8192 pages, LIFO batch:0
>> [ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
>> [ 0.000000] pcpu-alloc: [0] 0
>> [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on.
>> Total pages: 8128
>> [ 0.000000] Kernel command line: console=ttyS0,115200n8 earlyprintk
>> root=/dev/mmcblk0p1 rw rootwait debug
>> [ 0.000000] PID hash table entries: 128 (order: -3, 512 bytes)
>> [ 0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
>> [ 0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
>> [ 0.000000] Memory: 28852K/32768K available (2718K kernel code, 93K
>> rwdata, 484K rodata, 115K init, 126K bss, 3916K reserved)
>> [ 0.000000] Virtual kernel memory layout:
>> [ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB)
>> [ 0.000000] fixmap : 0xffc00000 - 0xffe00000 (2048 kB)
>> [ 0.000000] vmalloc : 0xc2800000 - 0xff000000 ( 968 MB)
>> [ 0.000000] lowmem : 0xc0000000 - 0xc2000000 ( 32 MB)
>> [ 0.000000] .text : 0xc0008000 - 0xc0328aec (3203 kB)
>> [ 0.000000] .init : 0xc0329000 - 0xc0345ddc ( 116 kB)
>> [ 0.000000] .data : 0xc0346000 - 0xc035d700 ( 94 kB)
>> [ 0.000000] .bss : 0xc035d700 - 0xc037cf24 ( 127 kB)
>> [ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
>> [ 0.000000] Preemptible hierarchical RCU implementation.
>> [ 0.000000] NR_IRQS:16 nr_irqs:16 16
>> [ 0.000000] sched_clock: 32 bits at 100 Hz, resolution 10000000ns,
>> wraps every 21474836480000000ns
>> [ 0.010000] Calibrating delay loop... 147.86 BogoMIPS (lpj=739328)
>> [ 0.090000] pid_max: default: 4096 minimum: 301
>> [ 0.090000] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
>> [ 0.100000] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
>> [ 0.110000] CPU: Testing write buffer coherency: ok
>> [ 0.120000] Setting up static identity map for 0x296938 - 0x296980
>> [ 0.140000] Unhandled fault: alignment exception (0x801) at 0x00000003
>
> I've been seeing the same crash starting with next-20140818. I have slab
> allocation debugging enabled and the above unhandled fault is apparently
> caused by in-use poisoning:
>
> [ 0.301383] Unable to handle kernel paging request at virtual address 5a5a5a5e
>
> The below patch works "fixes" it for me, though I have no idea why it's
> needed all of a sudden.
FWIW, bisecting the boot failure between next-20140818 (bad) and
v3.17-rc1 (good) points the finger at:
# first bad commit: [89f7ca1af15bdfe7a6aed343032a84af2a69f736] vfs:
Keep a list of mounts on a mount point.
Kevin
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH] fs: Initialize mountpoint list head in new_mountpoint()
2014-08-18 15:33 ` Thierry Reding
2014-08-18 19:33 ` Kevin Hilman
@ 2014-08-19 2:43 ` Murilo Opsfelder Araujo
2014-08-19 7:01 ` Thierry Reding
2014-08-20 12:35 ` fs: panic in mnt_set_mountpoint Jonas Jensen
2 siblings, 1 reply; 8+ messages in thread
From: Murilo Opsfelder Araujo @ 2014-08-19 2:43 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel
Cc: viro, thierry.reding, jonas.jensen, Murilo Opsfelder Araujo
The commit 89f7ca1af15bdfe7a6aed343032a84af2a69f736 makes next-20140818
to panic because mountpoint list head was not initialized. Initializing
it with NULL fixes the problem.
commit 89f7ca1af15bdfe7a6aed343032a84af2a69f736
Author: Eric W. Biederman <ebiederman@twitter.com>
Date: Sun Sep 22 19:37:01 2013 -0700
vfs: Keep a list of mounts on a mount point
To spot any possible problems call BUG if a mountpoint
is put when it's list of mounts is not empty.
AV: use hlist instead of list_head
Signed-off-by: Murilo Opsfelder Araujo <mopsfelder@gmail.com>
---
fs/namespace.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/namespace.c b/fs/namespace.c
index 1a2bbef..1a00bac 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -736,6 +736,7 @@ static struct mountpoint *new_mountpoint(struct dentry *dentry)
return ERR_PTR(ret);
}
+ INIT_HLIST_HEAD(&mp->m_list);
mp->m_dentry = dentry;
mp->m_count = 1;
hlist_add_head(&mp->m_hash, chain);
--
2.1.0.rc2.234.ge4c5f60
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] fs: Initialize mountpoint list head in new_mountpoint()
2014-08-19 2:43 ` [PATCH] fs: Initialize mountpoint list head in new_mountpoint() Murilo Opsfelder Araujo
@ 2014-08-19 7:01 ` Thierry Reding
2014-08-19 13:49 ` Murilo Opsfelder Araújo
0 siblings, 1 reply; 8+ messages in thread
From: Thierry Reding @ 2014-08-19 7:01 UTC (permalink / raw)
To: Murilo Opsfelder Araujo; +Cc: linux-fsdevel, linux-kernel, viro, jonas.jensen
[-- Attachment #1: Type: text/plain, Size: 929 bytes --]
On Mon, Aug 18, 2014 at 11:43:54PM -0300, Murilo Opsfelder Araujo wrote:
> The commit 89f7ca1af15bdfe7a6aed343032a84af2a69f736 makes next-20140818
> to panic because mountpoint list head was not initialized. Initializing
> it with NULL fixes the problem.
>
> commit 89f7ca1af15bdfe7a6aed343032a84af2a69f736
> Author: Eric W. Biederman <ebiederman@twitter.com>
> Date: Sun Sep 22 19:37:01 2013 -0700
>
> vfs: Keep a list of mounts on a mount point
>
> To spot any possible problems call BUG if a mountpoint
> is put when it's list of mounts is not empty.
>
> AV: use hlist instead of list_head
>
> Signed-off-by: Murilo Opsfelder Araujo <mopsfelder@gmail.com>
> ---
> fs/namespace.c | 1 +
> 1 file changed, 1 insertion(+)
It's considered good etiquette and polite to credit the original author
of a patch. This should be:
Originally-by: Thierry Reding <treding@nvidia.com>
[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] fs: Initialize mountpoint list head in new_mountpoint()
2014-08-19 7:01 ` Thierry Reding
@ 2014-08-19 13:49 ` Murilo Opsfelder Araújo
0 siblings, 0 replies; 8+ messages in thread
From: Murilo Opsfelder Araújo @ 2014-08-19 13:49 UTC (permalink / raw)
Cc: linux-fsdevel, linux-kernel
On Tue, Aug 19, 2014 at 4:01 AM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Mon, Aug 18, 2014 at 11:43:54PM -0300, Murilo Opsfelder Araujo wrote:
>> The commit 89f7ca1af15bdfe7a6aed343032a84af2a69f736 makes next-20140818
>> to panic because mountpoint list head was not initialized. Initializing
>> it with NULL fixes the problem.
>>
>> commit 89f7ca1af15bdfe7a6aed343032a84af2a69f736
>> Author: Eric W. Biederman <ebiederman@twitter.com>
>> Date: Sun Sep 22 19:37:01 2013 -0700
>>
>> vfs: Keep a list of mounts on a mount point
>>
>> To spot any possible problems call BUG if a mountpoint
>> is put when it's list of mounts is not empty.
>>
>> AV: use hlist instead of list_head
>>
>> Signed-off-by: Murilo Opsfelder Araujo <mopsfelder@gmail.com>
>> ---
>> fs/namespace.c | 1 +
>> 1 file changed, 1 insertion(+)
>
> It's considered good etiquette and polite to credit the original author
> of a patch. This should be:
>
> Originally-by: Thierry Reding <treding@nvidia.com>
(resending to the lists)
Hello, Thierry.
I didn't know about it and you deserve all the credits, for sure.
I'm away from computer today. I'll send a v2 tomorrow night.
--
Murilo
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: fs: panic in mnt_set_mountpoint
2014-08-18 15:33 ` Thierry Reding
2014-08-18 19:33 ` Kevin Hilman
2014-08-19 2:43 ` [PATCH] fs: Initialize mountpoint list head in new_mountpoint() Murilo Opsfelder Araujo
@ 2014-08-20 12:35 ` Jonas Jensen
2 siblings, 0 replies; 8+ messages in thread
From: Jonas Jensen @ 2014-08-20 12:35 UTC (permalink / raw)
To: Thierry Reding; +Cc: linux-fsdevel, viro, linux-kernel, sfr
> diff --git a/fs/namespace.c b/fs/namespace.c
> index 4246696dc678..a6815027f225 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -736,6 +736,7 @@ static struct mountpoint *new_mountpoint(struct dentry *dentry)
> return ERR_PTR(ret);
> }
>
> + INIT_HLIST_HEAD(&mp->m_list);
> mp->m_dentry = dentry;
> mp->m_count = 1;
> hlist_add_head(&mp->m_hash, chain);
I can confirm this has been fixed in next-20140820, my boards boot
without panic after rebase (commit: "Merge remote-tracking branch
'vfs/for-next'" - 002561f4e9e40e5444a8776daeaa4e5a718c376c).
Thanks!
Jonas
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2014-08-20 12:35 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-08-18 11:09 fs: panic in mnt_set_mountpoint Jonas Jensen
2014-08-18 12:08 ` Ming Lei
2014-08-18 15:33 ` Thierry Reding
2014-08-18 19:33 ` Kevin Hilman
2014-08-19 2:43 ` [PATCH] fs: Initialize mountpoint list head in new_mountpoint() Murilo Opsfelder Araujo
2014-08-19 7:01 ` Thierry Reding
2014-08-19 13:49 ` Murilo Opsfelder Araújo
2014-08-20 12:35 ` fs: panic in mnt_set_mountpoint Jonas Jensen
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.