From: Damien Le Moal <Damien.LeMoal@wdc.com>
To: "Javier González" <javier@javigon.com>,
"jaegeuk@kernel.org" <jaegeuk@kernel.org>,
"yuchao0@huawei.com" <yuchao0@huawei.com>
Cc: "Javier González" <javier.gonz@samsung.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-f2fs-devel@lists.sourceforge.net"
<linux-f2fs-devel@lists.sourceforge.net>
Subject: Re: [f2fs-dev] [PATCH] f2fs: disble physical prealloc in LSF mount
Date: Mon, 25 Nov 2019 00:48:37 +0000 [thread overview]
Message-ID: <BYAPR04MB58166AE029D919C6610D8404E74A0@BYAPR04MB5816.namprd04.prod.outlook.com> (raw)
In-Reply-To: 20191122085952.12754-1-javier@javigon.com
On 2019/11/22 18:00, Javier González wrote:
> From: Javier González <javier.gonz@samsung.com>
>
> Fix file system corruption when using LFS mount (e.g., in zoned
> devices). Seems like the fallback into buffered I/O creates an
> inconsistency if the application is assuming both read and write DIO. I
> can easily reproduce a corruption with a simple RocksDB test.
>
> Might be that the f2fs_forced_buffered_io path brings some problems too,
> but I have not seen other failures besides this one.
>
> Problem reproducible without a zoned block device, simply by forcing
> LFS mount:
>
> $ sudo mkfs.f2fs -f -m /dev/nvme0n1
> $ sudo mount /dev/nvme0n1 /mnt/f2fs
> $ sudo /opt/rocksdb/db_bench --benchmarks=fillseq --use_existing_db=0
> --use_direct_reads=true --use_direct_io_for_flush_and_compaction=true
> --db=/mnt/f2fs --num=5000 --value_size=1048576 --verify_checksum=1
> --block_size=65536
>
> Note that the options that cause the problem are:
> --use_direct_reads=true --use_direct_io_for_flush_and_compaction=true
>
> Fixes: f9d6d0597698 ("f2fs: fix out-place-update DIO write")
>
> Signed-off-by: Javier González <javier.gonz@samsung.com>
> ---
> fs/f2fs/data.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 5755e897a5f0..b045dd6ab632 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1081,9 +1081,6 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
> return err;
> }
>
> - if (direct_io && allow_outplace_dio(inode, iocb, from))
> - return 0;
Since for LFS mode, all DIOs can end up out of place, I think that it
may be better to change allow_outplace_dio() to always return true in
the case of LFS mode. So may be something like:
static inline int allow_outplace_dio(struct inode *inode,
struct kiocb *iocb, struct iov_iter *iter)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
int rw = iov_iter_rw(iter);
return test_opt(sbi, LFS) ||
(rw == WRITE && !block_unaligned_IO(inode, iocb, iter));
}
instead of the original:
static inline int allow_outplace_dio(struct inode *inode,
struct kiocb *iocb, struct iov_iter *iter)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
int rw = iov_iter_rw(iter);
return (test_opt(sbi, LFS) && (rw == WRITE) &&
!block_unaligned_IO(inode, iocb, iter));
}
Thoughts ?
> -
> if (is_inode_flag_set(inode, FI_NO_PREALLOC))
> return 0;
>
>
--
Damien Le Moal
Western Digital Research
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Linux-f2fs-devel mailing list
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next prev parent reply other threads:[~2019-11-25 1:04 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-22 8:59 [f2fs-dev] [PATCH] f2fs: disble physical prealloc in LSF mount Javier González
2019-11-25 0:48 ` Damien Le Moal [this message]
2019-11-25 19:03 ` Javier González
2019-11-26 2:06 ` Damien Le Moal
2019-11-26 3:57 ` Javier González
2019-11-26 6:19 ` Damien Le Moal
2019-11-26 6:20 ` Damien Le Moal
2019-11-26 6:43 ` Javier González
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