Re: [f2fs-dev] [PATCH v2] f2fs: fix hungtask when decompressed fail

[Chao Yu <chao@kernel.org>]

Hi Fengnan,

Sorry for the delay.

I guess we can merge this patch, but let me check whether there
is another solution, since mm guys want to remove PG_error usage
to save one bit slot in page.flags.

On 2022/11/1 17:41, fengnan chang wrote:
> friendly ping...
> 
> fengnan chang <fengnanchang@gmail.com> 于2022年10月14日周五 16:46写道：
>>
>> ping,  it seems this had been forgotten.
>>
>>> 2022年6月8日 21:48，Fengnan Chang <fengnanchang@gmail.com> 写道：
>>>
>>> When decompressed failed, f2fs_prepare_compress_overwrite will enter
>>> endless loop, may casue hungtask.
>>>
>>> [   14.088665] F2FS-fs (nvme0n1): lz4 decompress failed, ret:-4155
>>> [   14.089851] F2FS-fs (nvme0n1): lz4 decompress failed, ret:-4155
>>>
>>> Signed-off-by: Fengnan Chang <fengnanchang@gmail.com>
>>> ---
>>> fs/f2fs/compress.c | 21 ++++++++++++++++-----
>>> 1 file changed, 16 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
>>> index 24824cd96f36..1764e3859262 100644
>>> --- a/fs/f2fs/compress.c
>>> +++ b/fs/f2fs/compress.c
>>> @@ -1060,7 +1060,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
>>>        sector_t last_block_in_bio;
>>>        unsigned fgp_flag = FGP_LOCK | FGP_WRITE | FGP_CREAT;
>>>        pgoff_t start_idx = start_idx_of_cluster(cc);
>>> -     int i, ret;
>>> +     int i, ret, retry_count = 3;

Wrap magic number w/ macro?

>>>
>>> retry:
>>>        ret = f2fs_is_compressed_cluster(cc->inode, start_idx);
>>> @@ -1120,7 +1120,12 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
>>>                        f2fs_put_rpages(cc);
>>>                        f2fs_unlock_rpages(cc, i + 1);
>>>                        f2fs_destroy_compress_ctx(cc, true);
>>> -                     goto retry;
>>> +                     retry_count--;
>>> +                     if (PageError(page) && !retry_count) {
>>> +                             ret = -EIO;
>>> +                             goto out;
>>> +                     } else
>>> +                             goto retry;

} else {
	goto retry;
}

>>>                }
>>>        }
>>>
>>> @@ -1657,10 +1662,16 @@ static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed)
>>>                if (!rpage)
>>>                        continue;
>>>
>>> -             /* PG_error was set if verity failed. */
>>> -             if (failed || PageError(rpage)) {
>>> +             if (failed) {
>>> +                     /* decompress page failed */
>>> +                     ClearPageUptodate(rpage);
>>> +                     SetPageError(rpage);
>>> +             } else if (PageError(rpage)) {
>>> +                     /*
>>> +                      * PG_error was set if verity failed.
>>> +                      * will re-read again later.
>>> +                      */
>>>                        ClearPageUptodate(rpage);
>>> -                     /* will re-read again later */
>>>                        ClearPageError(rpage);
>>>                } else {
>>>                        SetPageUptodate(rpage);
>>> --
>>> 2.25.1
>>>
>>


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel