From: Jan Kara <jack@suse.cz>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] FAT: DIO-write fallback to normal buffered
Date: Wed, 14 Feb 2007 11:55:22 +0100 [thread overview]
Message-ID: <20070214105522.GA23203@duck.suse.cz> (raw)
In-Reply-To: <87ejoynkcu.fsf@duaron.myhome.or.jp>
On Sat 10-02-07 23:44:01, OGAWA Hirofumi wrote:
> [RESEND: forget to add linux-kernel@vger.kernel.org]
>
> If the DIO write on FAT is expanding the size, it will be fail by -EINVAL,
> because FAT can't handle it now.
>
> This patch fallback it to the normal buffered-write and would return
> success.
>
> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Jan Kara <jack@suse.cz>
Just to explain a bit: I think that returning EINVAL is quite unexpected
for users in this case (I actually got a bugreport which turned out to be
this problem) and fallback to buffered IO seems to be a reasonable thing to
do. Probably it's not the cleanest solution but for FAT I think it's good
enough ;).
Honza
> ---
>
> fs/fat/inode.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff -puN fs/fat/inode.c~fat_direct-io-fallback fs/fat/inode.c
> --- linux-2.6/fs/fat/inode.c~fat_direct-io-fallback 2007-02-10 22:08:33.000000000 +0900
> +++ linux-2.6-hirofumi/fs/fat/inode.c 2007-02-10 22:08:33.000000000 +0900
> @@ -173,10 +173,12 @@ static ssize_t fat_direct_IO(int rw, str
> *
> * But we must fill the remaining area or hole by nul for
> * updating ->mmu_private.
> + *
> + * Return 0, and fallback to normal buffered write.
> */
> loff_t size = offset + iov_length(iov, nr_segs);
> if (MSDOS_I(inode)->mmu_private < size)
> - return -EINVAL;
> + return 0;
> }
>
> /*
> _
--
Jan Kara <jack@suse.cz>
SuSE CR Labs
prev parent reply other threads:[~2007-02-14 10:51 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87sldenkg0.fsf@duaron.myhome.or.jp>
2007-02-10 14:44 ` [PATCH] FAT: DIO-write fallback to normal buffered OGAWA Hirofumi
2007-02-14 10:55 ` Jan Kara [this message]
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