* [Ocfs2-devel] [QUESTION] An NULL pointer dereference problem which was caused when dereference journal head
@ 2020-02-20 8:48 wangyan
2020-02-20 10:06 ` Jan Kara
0 siblings, 1 reply; 3+ messages in thread
From: wangyan @ 2020-02-20 8:48 UTC (permalink / raw)
To: ocfs2-devel
Hi all,
I met an null pointer dereference problem, the running environment:
kernel version: 4.19
A cluster with two nodes, 5 luns mounted on two nodes, and do some
file operations like dd/fallocate/truncate/rm on every lun with storage
network disconnection.
The fallocate operation on dm-23-45 caused an null pointer dereference.
The information of NULL pointer dereference as follows:
[577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45.
[577992.878290] Aborting journal on device dm-23-45.
...
[577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46.
[577992.890908] __journal_remove_journal_head: freeing b_committed_data
[577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30
[577992.890918] __journal_remove_journal_head: freeing b_committed_data
[577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30
[577992.890922] __journal_remove_journal_head: freeing b_committed_data
[577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30
[577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30
[577992.890928] __journal_remove_journal_head: freeing b_committed_data
[577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30
[577992.890933] __journal_remove_journal_head: freeing b_committed_data
[577992.890939] __journal_remove_journal_head: freeing b_committed_data
[577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
[577992.890950] Mem abort info:
[577992.890951] ESR = 0x96000004
[577992.890952] Exception class = DABT (current EL), IL = 32 bits
[577992.890952] SET = 0, FnV = 0
[577992.890953] EA = 0, S1PTW = 0
[577992.890954] Data abort info:
[577992.890955] ISV = 0, ISS = 0x00000004
[577992.890956] CM = 0, WnR = 0
[577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9
[577992.890960] [0000000000000020] pgd=0000000000000000
[577992.890964] Internal error: Oops: 96000004 [#1] SMP
[577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd)
[577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G W OE 4.19.36 #1
[577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019
[577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO)
[577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
[577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2]
[577992.891084] sp : ffff0000c8e2b810
[577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000
[577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70
[577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2
[577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30
[577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000
[577992.891097] x19: ffff000001681638 x18: ffffffffffffffff
[577992.891098] x17: 0000000000000000 x16: ffff000080a03df0
[577992.891100] x15: ffff0000811d9708 x14: 203d207375746174
[577992.891101] x13: 73203a524f525245 x12: 20373439343a6565
[577992.891103] x11: 0000000000000038 x10: 0101010101010101
[577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f
[577992.891109] x7 : 0000000000000000 x6 : 0000000000000080
[577992.891110] x5 : 0000000000000000 x4 : 0000000000000002
[577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00
[577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000
[577992.891116] Call trace:
[577992.891139] _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
[577992.891162] _ocfs2_free_clusters+0x100/0x290 [ocfs2]
[577992.891185] ocfs2_free_clusters+0x50/0x68 [ocfs2]
[577992.891206] ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2]
[577992.891227] ocfs2_add_inode_data+0x94/0xc8 [ocfs2]
[577992.891248] ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2]
[577992.891269] ocfs2_allocate_extents+0x14c/0x338 [ocfs2]
[577992.891290] __ocfs2_change_file_space+0x3f8/0x610 [ocfs2]
[577992.891309] ocfs2_fallocate+0xe4/0x128 [ocfs2]
[577992.891316] vfs_fallocate+0x11c/0x250
[577992.891317] ksys_fallocate+0x54/0x88
[577992.891319] __arm64_sys_fallocate+0x28/0x38
[577992.891323] el0_svc_common+0x78/0x130
[577992.891325] el0_svc_handler+0x38/0x78
[577992.891327] el0_svc+0x8/0xc
My analysis process as follows:
ocfs2_fallocate
__ocfs2_change_file_space
ocfs2_allocate_extents
ocfs2_extend_allocation
ocfs2_add_inode_data
ocfs2_add_clusters_in_btree
ocfs2_insert_extent
ocfs2_do_insert_extent
ocfs2_rotate_tree_right
ocfs2_extend_rotate_transaction
ocfs2_extend_trans
jbd2_journal_restart
jbd2__journal_restart
/* handle->h_transaction is NULL,
* is_handle_aborted(handle) is true
*/
handle->h_transaction = NULL;
start_this_handle
return -EROFS;
ocfs2_free_clusters
_ocfs2_free_clusters
_ocfs2_free_suballoc_bits
ocfs2_block_group_clear_bits
ocfs2_journal_access_gd
__ocfs2_journal_access
jbd2_journal_get_undo_access
/* I think jbd2_write_access_granted() will
* return true, because do_get_write_access()
* will return -EROFS.
*/
if (jbd2_write_access_granted(...)) return 0;
do_get_write_access
/* handle->h_transaction is NULL, it will
* return -EROFS here, so do_get_write_access()
* was not called.
*/
if (is_handle_aborted(handle)) return -EROFS;
/* bh2jh(group_bh) is NULL, caused NULL
pointer dereference */
undo_bg = (struct ocfs2_group_desc *)
bh2jh(group_bh)->b_committed_data;
I found the log "__journal_remove_journal_head: freeing b_committed_data"
before causing NULL pointer dereference which will be printed when remove
journal head.
So, I think bh2jh(group_bh) is removed after ocfs2_journal_access_gd() and
before call "bh2jh(group_bh)->b_committed_data", I don't know if this
condition will happen and if the analysis result is right?
Thanks,
Yan Wang
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Ocfs2-devel] [QUESTION] An NULL pointer dereference problem which was caused when dereference journal head
2020-02-20 8:48 [Ocfs2-devel] [QUESTION] An NULL pointer dereference problem which was caused when dereference journal head wangyan
@ 2020-02-20 10:06 ` Jan Kara
2020-02-20 10:25 ` wangyan
0 siblings, 1 reply; 3+ messages in thread
From: Jan Kara @ 2020-02-20 10:06 UTC (permalink / raw)
To: ocfs2-devel
On Thu 20-02-20 16:48:56, wangyan wrote:
> Hi all,
>
> I met an null pointer dereference problem, the running environment:
> kernel version: 4.19
> A cluster with two nodes, 5 luns mounted on two nodes, and do some
> file operations like dd/fallocate/truncate/rm on every lun with storage
> network disconnection.
>
> The fallocate operation on dm-23-45 caused an null pointer dereference.
>
> The information of NULL pointer dereference as follows:
> [577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45.
> [577992.878290] Aborting journal on device dm-23-45.
> ...
> [577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46.
> [577992.890908] __journal_remove_journal_head: freeing b_committed_data
> [577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30
> [577992.890918] __journal_remove_journal_head: freeing b_committed_data
> [577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30
> [577992.890922] __journal_remove_journal_head: freeing b_committed_data
> [577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30
> [577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30
> [577992.890928] __journal_remove_journal_head: freeing b_committed_data
> [577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30
> [577992.890933] __journal_remove_journal_head: freeing b_committed_data
> [577992.890939] __journal_remove_journal_head: freeing b_committed_data
> [577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
> [577992.890950] Mem abort info:
> [577992.890951] ESR = 0x96000004
> [577992.890952] Exception class = DABT (current EL), IL = 32 bits
> [577992.890952] SET = 0, FnV = 0
> [577992.890953] EA = 0, S1PTW = 0
> [577992.890954] Data abort info:
> [577992.890955] ISV = 0, ISS = 0x00000004
> [577992.890956] CM = 0, WnR = 0
> [577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9
> [577992.890960] [0000000000000020] pgd=0000000000000000
> [577992.890964] Internal error: Oops: 96000004 [#1] SMP
> [577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd)
> [577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G W OE 4.19.36 #1
> [577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019
> [577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO)
> [577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
> [577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2]
> [577992.891084] sp : ffff0000c8e2b810
> [577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000
> [577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70
> [577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2
> [577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30
> [577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000
> [577992.891097] x19: ffff000001681638 x18: ffffffffffffffff
> [577992.891098] x17: 0000000000000000 x16: ffff000080a03df0
> [577992.891100] x15: ffff0000811d9708 x14: 203d207375746174
> [577992.891101] x13: 73203a524f525245 x12: 20373439343a6565
> [577992.891103] x11: 0000000000000038 x10: 0101010101010101
> [577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f
> [577992.891109] x7 : 0000000000000000 x6 : 0000000000000080
> [577992.891110] x5 : 0000000000000000 x4 : 0000000000000002
> [577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00
> [577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000
> [577992.891116] Call trace:
> [577992.891139] _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
> [577992.891162] _ocfs2_free_clusters+0x100/0x290 [ocfs2]
> [577992.891185] ocfs2_free_clusters+0x50/0x68 [ocfs2]
> [577992.891206] ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2]
> [577992.891227] ocfs2_add_inode_data+0x94/0xc8 [ocfs2]
> [577992.891248] ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2]
> [577992.891269] ocfs2_allocate_extents+0x14c/0x338 [ocfs2]
> [577992.891290] __ocfs2_change_file_space+0x3f8/0x610 [ocfs2]
> [577992.891309] ocfs2_fallocate+0xe4/0x128 [ocfs2]
> [577992.891316] vfs_fallocate+0x11c/0x250
> [577992.891317] ksys_fallocate+0x54/0x88
> [577992.891319] __arm64_sys_fallocate+0x28/0x38
> [577992.891323] el0_svc_common+0x78/0x130
> [577992.891325] el0_svc_handler+0x38/0x78
> [577992.891327] el0_svc+0x8/0xc
>
> My analysis process as follows:
> ocfs2_fallocate
> __ocfs2_change_file_space
> ocfs2_allocate_extents
> ocfs2_extend_allocation
> ocfs2_add_inode_data
> ocfs2_add_clusters_in_btree
> ocfs2_insert_extent
> ocfs2_do_insert_extent
> ocfs2_rotate_tree_right
> ocfs2_extend_rotate_transaction
> ocfs2_extend_trans
> jbd2_journal_restart
> jbd2__journal_restart
> /* handle->h_transaction is NULL,
> * is_handle_aborted(handle) is true
> */
> handle->h_transaction = NULL;
> start_this_handle
> return -EROFS;
> ocfs2_free_clusters
> _ocfs2_free_clusters
> _ocfs2_free_suballoc_bits
> ocfs2_block_group_clear_bits
> ocfs2_journal_access_gd
> __ocfs2_journal_access
> jbd2_journal_get_undo_access
> /* I think jbd2_write_access_granted() will
> * return true, because do_get_write_access()
> * will return -EROFS.
> */
> if (jbd2_write_access_granted(...)) return 0;
> do_get_write_access
> /* handle->h_transaction is NULL, it will
> * return -EROFS here, so do_get_write_access()
> * was not called.
> */
> if (is_handle_aborted(handle)) return -EROFS;
> /* bh2jh(group_bh) is NULL, caused NULL
> pointer dereference */
> undo_bg = (struct ocfs2_group_desc *)
> bh2jh(group_bh)->b_committed_data;
>
> I found the log "__journal_remove_journal_head: freeing b_committed_data"
> before causing NULL pointer dereference which will be printed when remove
> journal head.
>
> So, I think bh2jh(group_bh) is removed after ocfs2_journal_access_gd() and
> before call "bh2jh(group_bh)->b_committed_data", I don't know if this
> condition will happen and if the analysis result is right?
Thanks for the analysis! Yes, what you write seems to be possible because
if handle->h_transaction == NULL, then jbd2_write_access_granted() does not
really guarantee that journal_head will stay around, not even speaking of
its b_committed_data.
I think a proper fix is to move is_handle_aborted() check from
do_get_write_access() into jbd2_journal_get_undo_access() and
jbd2_journal_get_write_access() before the call to
jbd2_write_access_granted().
Will you send a patch to fix this or should I do it?
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Ocfs2-devel] [QUESTION] An NULL pointer dereference problem which was caused when dereference journal head
2020-02-20 10:06 ` Jan Kara
@ 2020-02-20 10:25 ` wangyan
0 siblings, 0 replies; 3+ messages in thread
From: wangyan @ 2020-02-20 10:25 UTC (permalink / raw)
To: ocfs2-devel
Thanks a lot!
I will send a patch to help you fix this later.
Thanks,
Yan Wang
On 2020/2/20 18:06, Jan Kara wrote:
> On Thu 20-02-20 16:48:56, wangyan wrote:
>> Hi all,
>>
>> I met an null pointer dereference problem, the running environment:
>> kernel version: 4.19
>> A cluster with two nodes, 5 luns mounted on two nodes, and do some
>> file operations like dd/fallocate/truncate/rm on every lun with storage
>> network disconnection.
>>
>> The fallocate operation on dm-23-45 caused an null pointer dereference.
>>
>> The information of NULL pointer dereference as follows:
>> [577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45.
>> [577992.878290] Aborting journal on device dm-23-45.
>> ...
>> [577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46.
>> [577992.890908] __journal_remove_journal_head: freeing b_committed_data
>> [577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30
>> [577992.890918] __journal_remove_journal_head: freeing b_committed_data
>> [577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30
>> [577992.890922] __journal_remove_journal_head: freeing b_committed_data
>> [577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30
>> [577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30
>> [577992.890928] __journal_remove_journal_head: freeing b_committed_data
>> [577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30
>> [577992.890933] __journal_remove_journal_head: freeing b_committed_data
>> [577992.890939] __journal_remove_journal_head: freeing b_committed_data
>> [577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
>> [577992.890950] Mem abort info:
>> [577992.890951] ESR = 0x96000004
>> [577992.890952] Exception class = DABT (current EL), IL = 32 bits
>> [577992.890952] SET = 0, FnV = 0
>> [577992.890953] EA = 0, S1PTW = 0
>> [577992.890954] Data abort info:
>> [577992.890955] ISV = 0, ISS = 0x00000004
>> [577992.890956] CM = 0, WnR = 0
>> [577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9
>> [577992.890960] [0000000000000020] pgd=0000000000000000
>> [577992.890964] Internal error: Oops: 96000004 [#1] SMP
>> [577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd)
>> [577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G W OE 4.19.36 #1
>> [577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019
>> [577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO)
>> [577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
>> [577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2]
>> [577992.891084] sp : ffff0000c8e2b810
>> [577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000
>> [577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70
>> [577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2
>> [577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30
>> [577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000
>> [577992.891097] x19: ffff000001681638 x18: ffffffffffffffff
>> [577992.891098] x17: 0000000000000000 x16: ffff000080a03df0
>> [577992.891100] x15: ffff0000811d9708 x14: 203d207375746174
>> [577992.891101] x13: 73203a524f525245 x12: 20373439343a6565
>> [577992.891103] x11: 0000000000000038 x10: 0101010101010101
>> [577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f
>> [577992.891109] x7 : 0000000000000000 x6 : 0000000000000080
>> [577992.891110] x5 : 0000000000000000 x4 : 0000000000000002
>> [577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00
>> [577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000
>> [577992.891116] Call trace:
>> [577992.891139] _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
>> [577992.891162] _ocfs2_free_clusters+0x100/0x290 [ocfs2]
>> [577992.891185] ocfs2_free_clusters+0x50/0x68 [ocfs2]
>> [577992.891206] ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2]
>> [577992.891227] ocfs2_add_inode_data+0x94/0xc8 [ocfs2]
>> [577992.891248] ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2]
>> [577992.891269] ocfs2_allocate_extents+0x14c/0x338 [ocfs2]
>> [577992.891290] __ocfs2_change_file_space+0x3f8/0x610 [ocfs2]
>> [577992.891309] ocfs2_fallocate+0xe4/0x128 [ocfs2]
>> [577992.891316] vfs_fallocate+0x11c/0x250
>> [577992.891317] ksys_fallocate+0x54/0x88
>> [577992.891319] __arm64_sys_fallocate+0x28/0x38
>> [577992.891323] el0_svc_common+0x78/0x130
>> [577992.891325] el0_svc_handler+0x38/0x78
>> [577992.891327] el0_svc+0x8/0xc
>>
>> My analysis process as follows:
>> ocfs2_fallocate
>> __ocfs2_change_file_space
>> ocfs2_allocate_extents
>> ocfs2_extend_allocation
>> ocfs2_add_inode_data
>> ocfs2_add_clusters_in_btree
>> ocfs2_insert_extent
>> ocfs2_do_insert_extent
>> ocfs2_rotate_tree_right
>> ocfs2_extend_rotate_transaction
>> ocfs2_extend_trans
>> jbd2_journal_restart
>> jbd2__journal_restart
>> /* handle->h_transaction is NULL,
>> * is_handle_aborted(handle) is true
>> */
>> handle->h_transaction = NULL;
>> start_this_handle
>> return -EROFS;
>> ocfs2_free_clusters
>> _ocfs2_free_clusters
>> _ocfs2_free_suballoc_bits
>> ocfs2_block_group_clear_bits
>> ocfs2_journal_access_gd
>> __ocfs2_journal_access
>> jbd2_journal_get_undo_access
>> /* I think jbd2_write_access_granted() will
>> * return true, because do_get_write_access()
>> * will return -EROFS.
>> */
>> if (jbd2_write_access_granted(...)) return 0;
>> do_get_write_access
>> /* handle->h_transaction is NULL, it will
>> * return -EROFS here, so do_get_write_access()
>> * was not called.
>> */
>> if (is_handle_aborted(handle)) return -EROFS;
>> /* bh2jh(group_bh) is NULL, caused NULL
>> pointer dereference */
>> undo_bg = (struct ocfs2_group_desc *)
>> bh2jh(group_bh)->b_committed_data;
>>
>> I found the log "__journal_remove_journal_head: freeing b_committed_data"
>> before causing NULL pointer dereference which will be printed when remove
>> journal head.
>>
>> So, I think bh2jh(group_bh) is removed after ocfs2_journal_access_gd() and
>> before call "bh2jh(group_bh)->b_committed_data", I don't know if this
>> condition will happen and if the analysis result is right?
>
> Thanks for the analysis! Yes, what you write seems to be possible because
> if handle->h_transaction == NULL, then jbd2_write_access_granted() does not
> really guarantee that journal_head will stay around, not even speaking of
> its b_committed_data.
>
> I think a proper fix is to move is_handle_aborted() check from
> do_get_write_access() into jbd2_journal_get_undo_access() and
> jbd2_journal_get_write_access() before the call to
> jbd2_write_access_granted().
>
> Will you send a patch to fix this or should I do it?
>
> Honza
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-02-20 10:25 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2020-02-20 8:48 [Ocfs2-devel] [QUESTION] An NULL pointer dereference problem which was caused when dereference journal head wangyan
2020-02-20 10:06 ` Jan Kara
2020-02-20 10:25 ` wangyan
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