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From: Xiaoli Feng <xifeng@redhat.com>
To: CIFS <linux-cifs@vger.kernel.org>
Subject: Memory alignment requirement for Direct/IO
Date: Tue, 30 Apr 2019 05:01:06 -0400 (EDT)	[thread overview]
Message-ID: <151404631.6398428.1556614866154.JavaMail.zimbra@redhat.com> (raw)
In-Reply-To: <1666985748.6396792.1556614132673.JavaMail.zimbra@redhat.com>

Hello,

I setup samba server in upstream  and mount it in local with cache=none,vers=3.11. Then test
the Direct/IO function like this:

fd=open(fname, O_DIRECT | O_RDWR | O_CREAT, 0666))
lseek(fd, 0, SEEK_SET);
read(fd, buf, 1);

For local filesystem such as XFS, "read" will be failed because XFS has 512Byte memory aligment
for Direct/IO. But it's success for cifs. I don't know if it's expected. Could anybody tell me
more about Direct/IO for cifs?

Thanks.

-- 
Best regards!
XiaoLi Feng 冯小丽

Red Hat Software (Beijing) Co.,Ltd
filesystem-qe Team
IRC:xifeng，#channel: fs-qe
Tel:+86-10-8388112
9/F, Raycom

       reply	other threads:[~2019-04-30  9:01 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1666985748.6396792.1556614132673.JavaMail.zimbra@redhat.com>
2019-04-30  9:01 ` Xiaoli Feng [this message]
2019-05-01 15:35   ` Memory alignment requirement for Direct/IO Steve French

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