[Ocfs2-devel] [PATCH 2/2] ocfs2: fix trans extend while free cached blocks

[Joseph Qi <joseph.qi@huawei.com>]

Thanks Junxiao.
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>

On 2016/9/12 18:03, Junxiao Bi wrote:
> Root cause of this issue is the same with the one fixed by last patch,
> but this time credits for allocator inode and group descriptor may not
> be consumed before trans extend.
> 
> The following error was caught.
> 
> [  685.240276] WARNING: CPU: 0 PID: 2037 at fs/jbd2/transaction.c:269 start_this_handle+0x4c3/0x510 [jbd2]()
> [  685.240294] Modules linked in: ocfs2 nfsd lockd grace nfs_acl auth_rpcgss sunrpc autofs4 ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sd_mod sg ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ppdev xen_kbdfront fb_sys_fops sysimgblt sysfillrect syscopyarea xen_netfront parport_pc parport pcspkr i2c_piix4 i2c_core acpi_cpufreq ext4 jbd2 mbcache xen_blkfront floppy pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod
> [  685.240296] CPU: 0 PID: 2037 Comm: rm Tainted: G        W       4.1.12-37.6.3.el6uek.bug24573128v2.x86_64 #2
> [  685.240296] Hardware name: Xen HVM domU, BIOS 4.4.4OVM 02/11/2016
> [  685.240298]  000000000000010d ffff88007ac3f808 ffffffff816bc5bc 000000000000010d
> [  685.240300]  0000000000000000 ffff88007ac3f848 ffffffff81081475 ffff88007ac3f828
> [  685.240301]  ffff880037bbf000 ffff880037688210 0000000000000095 0000000000000050
> [  685.240301] Call Trace:
> [  685.240305]  [<ffffffff816bc5bc>] dump_stack+0x48/0x5c
> [  685.240308]  [<ffffffff81081475>] warn_slowpath_common+0x95/0xe0
> [  685.240310]  [<ffffffff810814da>] warn_slowpath_null+0x1a/0x20
> [  685.240313]  [<ffffffffa0080993>] start_this_handle+0x4c3/0x510 [jbd2]
> [  685.240317]  [<ffffffffa0088f95>] ? __jbd2_log_start_commit+0xe5/0xf0 [jbd2]
> [  685.240319]  [<ffffffff810c4eb3>] ? __wake_up+0x53/0x70
> [  685.240322]  [<ffffffffa0080b41>] jbd2__journal_restart+0x161/0x1b0 [jbd2]
> [  685.240325]  [<ffffffffa0080ba3>] jbd2_journal_restart+0x13/0x20 [jbd2]
> [  685.240340]  [<ffffffffa06d1cf4>] ocfs2_extend_trans+0x74/0x220 [ocfs2]
> [  685.240347]  [<ffffffffa069762b>] ocfs2_free_cached_blocks+0x16b/0x4e0 [ocfs2]
> [  685.240349]  [<ffffffff810e9131>] ? internal_add_timer+0x91/0xc0
> [  685.240356]  [<ffffffffa06981b0>] ocfs2_run_deallocs+0x70/0x270 [ocfs2]
> [  685.240363]  [<ffffffffa06a2894>] ocfs2_commit_truncate+0x474/0x6f0 [ocfs2]
> [  685.240374]  [<ffffffffa0744a40>] ? ocfs2_xattr_tree_et_ops+0x60/0xfffffffffffe8c00 [ocfs2]
> [  685.240384]  [<ffffffffa06d1960>] ? ocfs2_journal_access_eb+0x20/0x20 [ocfs2]
> [  685.240385]  [<ffffffff81202303>] ? __sb_end_write+0x33/0x70
> [  685.240394]  [<ffffffffa06ca57d>] ocfs2_truncate_for_delete+0xbd/0x380 [ocfs2]
> [  685.240402]  [<ffffffffa06ca1f4>] ? ocfs2_query_inode_wipe+0xf4/0x320 [ocfs2]
> [  685.240409]  [<ffffffffa06caed6>] ocfs2_wipe_inode+0x136/0x6a0 [ocfs2]
> [  685.240415]  [<ffffffffa06ca1f4>] ? ocfs2_query_inode_wipe+0xf4/0x320 [ocfs2]
> [  685.240422]  [<ffffffffa06cb6e2>] ocfs2_delete_inode+0x2a2/0x3e0 [ocfs2]
> [  685.240424]  [<ffffffff812298c9>] ? __inode_wait_for_writeback+0x69/0xc0
> [  685.240437]  [<ffffffffa0732100>] ? __PRETTY_FUNCTION__.112282+0x20/0xffffffffffffb500 [ocfs2]
> [  685.240444]  [<ffffffffa06cc1f8>] ocfs2_evict_inode+0x28/0x60 [ocfs2]
> [  685.240445]  [<ffffffff8121b81b>] evict+0xab/0x1a0
> [  685.240456]  [<ffffffffa0732100>] ? __PRETTY_FUNCTION__.112282+0x20/0xffffffffffffb500 [ocfs2]
> [  685.240457]  [<ffffffff8121ba06>] iput_final+0xf6/0x190
> [  685.240458]  [<ffffffff8121bb68>] iput+0xc8/0xe0
> [  685.240460]  [<ffffffff8120f9b7>] do_unlinkat+0x1b7/0x310
> [  685.240462]  [<ffffffff81126dbc>] ? __audit_syscall_entry+0xac/0x110
> [  685.240464]  [<ffffffff810236cc>] ? do_audit_syscall_entry+0x6c/0x70
> [  685.240465]  [<ffffffff81023823>] ? syscall_trace_enter_phase1+0x153/0x180
> [  685.240467]  [<ffffffff8120fd52>] SyS_unlinkat+0x22/0x40
> [  685.240468]  [<ffffffff816c122e>] system_call_fastpath+0x12/0x71
> [  685.240469] ---[ end trace a62437cb060baa71 ]---
> [  685.240470] JBD2: rm wants too many credits (149 > 128)
> 
> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
> ---
>  fs/ocfs2/alloc.c |   27 +++++++++------------------
>  1 file changed, 9 insertions(+), 18 deletions(-)
> 
> diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
> index 51128789a661..f165f867f332 100644
> --- a/fs/ocfs2/alloc.c
> +++ b/fs/ocfs2/alloc.c
> @@ -6404,43 +6404,34 @@ static int ocfs2_free_cached_blocks(struct ocfs2_super *osb,
>  		goto out_mutex;
>  	}
>  
> -	handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
> -	if (IS_ERR(handle)) {
> -		ret = PTR_ERR(handle);
> -		mlog_errno(ret);
> -		goto out_unlock;
> -	}
> -
>  	while (head) {
>  		if (head->free_bg)
>  			bg_blkno = head->free_bg;
>  		else
>  			bg_blkno = ocfs2_which_suballoc_group(head->free_blk,
>  							      head->free_bit);
> +		handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
> +		if (IS_ERR(handle)) {
> +			ret = PTR_ERR(handle);
> +			mlog_errno(ret);
> +			goto out_unlock;
> +		}
> +
>  		trace_ocfs2_free_cached_blocks(
>  		     (unsigned long long)head->free_blk, head->free_bit);
>  
>  		ret = ocfs2_free_suballoc_bits(handle, inode, di_bh,
>  					       head->free_bit, bg_blkno, 1);
> -		if (ret) {
> +		if (ret)
>  			mlog_errno(ret);
> -			goto out_journal;
> -		}
>  
> -		ret = ocfs2_extend_trans(handle, OCFS2_SUBALLOC_FREE);
> -		if (ret) {
> -			mlog_errno(ret);
> -			goto out_journal;
> -		}
> +		ocfs2_commit_trans(osb, handle);
>  
>  		tmp = head;
>  		head = head->free_next;
>  		kfree(tmp);
>  	}
>  
> -out_journal:
> -	ocfs2_commit_trans(osb, handle);
> -
>  out_unlock:
>  	ocfs2_inode_unlock(inode, 1);
>  	brelse(di_bh);
>