lkml.org 
[lkml]   [2022]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] erofs: wake up all waiters after z_erofs_lzma_head ready
From
The new patch has been upload. The modification points are as follower:

1. delete the period.

2. change 'W' to lowercase.

3. add a Reviewed-by tag.

On 6/27/22 06:40, Yuwen Chen wrote:
> When the user mounts the erofs second times, the decompression thread
> may hung. The problem happens due to a sequence of steps like the
> following:
>
> 1) Task A called z_erofs_load_lzma_config which obtain all of the node
> from the z_erofs_lzma_head.
>
> 2) At this time, task B called the z_erofs_lzma_decompress and wanted to
> get a node. But the z_erofs_lzma_head was empty, the Task B had to
> sleep.
>
> 3) Task A release nodes and push nodes into the z_erofs_lzma_head. But
> task B was still sleeping.
>
> One example report when the hung happens:
> task:kworker/u3:1 state:D stack:14384 pid: 86 ppid: 2 flags:0x00004000
> Workqueue: erofs_unzipd z_erofs_decompressqueue_work
> Call Trace:
> <TASK>
> __schedule+0x281/0x760
> schedule+0x49/0xb0
> z_erofs_lzma_decompress+0x4bc/0x580
> ? cpu_core_flags+0x10/0x10
> z_erofs_decompress_pcluster+0x49b/0xba0
> ? __update_load_avg_se+0x2b0/0x330
> ? __update_load_avg_se+0x2b0/0x330
> ? update_load_avg+0x5f/0x690
> ? update_load_avg+0x5f/0x690
> ? set_next_entity+0xbd/0x110
> ? _raw_spin_unlock+0xd/0x20
> z_erofs_decompress_queue.isra.0+0x2e/0x50
> z_erofs_decompressqueue_work+0x30/0x60
> process_one_work+0x1d3/0x3a0
> worker_thread+0x45/0x3a0
> ? process_one_work+0x3a0/0x3a0
> kthread+0xe2/0x110
> ? kthread_complete_and_exit+0x20/0x20
> ret_from_fork+0x22/0x30
> </TASK>
>
> Signed-off-by: Yuwen Chen <chenyuwen1@meizu.com>
> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> ---
> fs/erofs/decompressor_lzma.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c
> index 05a3063cf2bc..5e59b3f523eb 100644
> --- a/fs/erofs/decompressor_lzma.c
> +++ b/fs/erofs/decompressor_lzma.c
> @@ -143,6 +143,7 @@ int z_erofs_load_lzma_config(struct super_block *sb,
> DBG_BUGON(z_erofs_lzma_head);
> z_erofs_lzma_head = head;
> spin_unlock(&z_erofs_lzma_lock);
> + wake_up_all(&z_erofs_lzma_wq);
>
> z_erofs_lzma_max_dictsize = dict_size;
> mutex_unlock(&lzma_resize_mutex);

\
 
 \ /
  Last update: 2022-06-27 09:13    [W:0.050 / U:0.736 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site