On 2020/6/17 17:04, zhaowu...@wingtech.com wrote:
> From: Wuyun Zhao <zhaowu...@wingtech.com>
>
> Under some condition, the __write_node_page will submit a page which is not
> f2fs_in_warm_node_list and will not call f2fs_add_fsync_node_entry.
> f2fs_gc continue to run to invoke f2fs_iget -> do_read_inode to read the same
> node page
> and set code node, which make f2fs_in_warm_node_list become true,
> that will cause f2fs_bug_on in f2fs_del_fsync_node_entry when
> f2fs_write_end_io called.
Could you please add below race condition description into commit message?
- f2fs_write_end_io
- f2fs_iget
- do_read_inode
- set_cold_node
recover cold node flag
- f2fs_in_warm_node_list
- is_cold_node
if node is cold, assume we have added
node to fsync_node_list during writepages()
- f2fs_del_fsync_node_entry
- f2fs_bug_on() due to node page
is not in fsync_node_list
BTW, I'm curious about why we can lose cold flag for non-dir inode?
any clue to reproduce this bug (I mean losing cold flag)?
>
> [ 34.966133] Call trace:
> [ 34.969902] f2fs_del_fsync_node_entry+0x100/0x108
> [ 34.976071] f2fs_write_end_io+0x1e0/0x288
> [ 34.981539] bio_endio+0x248/0x270
> [ 34.986289] blk_update_request+0x2b0/0x4d8
> [ 34.991841] scsi_end_request+0x40/0x440
> [ 34.997126] scsi_io_completion+0xa4/0x748
> [ 35.002593] scsi_finish_command+0xdc/0x110
> [ 35.008143] scsi_softirq_done+0x118/0x150
> [ 35.013610] blk_done_softirq+0x8c/0xe8
> [ 35.018811] __do_softirq+0x2e8/0x578
> [ 35.023828] irq_exit+0xfc/0x120
> [ 35.028398] handle_IPI+0x1d8/0x330
> [ 35.033233] gic_handle_irq+0x110/0x1d4
> [ 35.038433] el1_irq+0xb4/0x130
> [ 35.042917] kmem_cache_alloc+0x3f0/0x418
> [ 35.048288] radix_tree_node_alloc+0x50/0xf8
> [ 35.053933] __radix_tree_create+0xf8/0x188
> [ 35.059484] __radix_tree_insert+0x3c/0x128
> [ 35.065035] add_gc_inode+0x90/0x118
> [ 35.069967] f2fs_gc+0x1b80/0x2d70
> [ 35.074718] f2fs_disable_checkpoint+0x94/0x1d0
> [ 35.080621] f2fs_fill_super+0x10c4/0x1b88
> [ 35.086088] mount_bdev+0x194/0x1e0
> [ 35.090923] f2fs_mount+0x40/0x50
> [ 35.095589] mount_fs+0xb4/0x190
> [ 35.100159] vfs_kern_mount+0x80/0x1d8
> [ 35.105260] do_mount+0x478/0xf18
> [ 35.109926] ksys_mount+0x90/0xd0
> [ 35.114592] __arm64_sys_mount+0x24/0x38
>
> Signed-off-by: Wuyun Zhao <zhaowu...@wingtech.com>
Reviewed-by: Chao Yu <yuch...@huawei.com>
Thanks,
> ---
> fs/f2fs/inode.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index be6ac33..0df5c8c 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -402,6 +402,7 @@ static int do_read_inode(struct inode *inode)
>
> /* try to recover cold bit for non-dir inode */
> if (!S_ISDIR(inode->i_mode) && !is_cold_node(node_page)) {
> + f2fs_wait_on_page_writeback(node_page, NODE, true, true);
> set_cold_node(node_page, false);
> set_page_dirty(node_page);
> }
>
