All of lore.kernel.org
 help / color / mirror / Atom feed
From: Gu Zheng <guzheng1@huawei.com>
To: <bfields@fieldses.org>, <jlayton@poochiereds.net>
Cc: <linux-nfs@vger.kernel.org>, <houtao1@huawei.com>,
	Zhaohongjiang <zhaohongjiang@huawei.com>, <miaoxie@huawei.com>
Subject: nfs+ext4,can not umount the ext4 mountpoint
Date: Tue, 16 May 2017 20:57:03 +0800	[thread overview]
Message-ID: <591AF71F.1040703@huawei.com> (raw)

Hi all:
we have a test about nfs on linux 4.11.
the detailed process as follow:
server ip:9.81.231.141                    		client
mount -t ext4 /dev/vdb /home/nfs/aa
							mount -t nfs -o sync,tcp,vers=3,noac,timeo=70,retrans=3 9.81.231.141:/home/nfs  /tmp/aa/
							ls /tmp/aa
umount /home/nfs/aa

the umount remind "target is busy".
so we analyze the code , a reference count which is named "mnt_count" add 1 in rqst_exp_get_by_name() after execute the "ls" order.
the detailed call is nfsd3_proc_lookup->nfsd_lookup->nfsd_lookup_dentry->nfsd_cross_mnt->rqst_exp_get_by_name->exp_get_by_name->svc_export_lookup->sunrpc_cache_lookup->svc_export_init->path_get
the reference count can't be subtracted untill we stop nfsd or tcp idle timeout on server. the system call the cache_flush() to subtract the count.
then we can umount successfully.

do dou have some patches can umount immediately or some suggestions?


             reply	other threads:[~2017-05-16 12:57 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-16 12:57 Gu Zheng [this message]
2017-05-16 17:42 ` nfs+ext4,can not umount the ext4 mountpoint J. Bruce Fields
2017-05-17  7:18   ` Gu Zheng
2017-05-17 15:46     ` J. Bruce Fields
2017-05-18 10:59       ` Gu Zheng

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=591AF71F.1040703@huawei.com \
    --to=guzheng1@huawei.com \
    --cc=bfields@fieldses.org \
    --cc=houtao1@huawei.com \
    --cc=jlayton@poochiereds.net \
    --cc=linux-nfs@vger.kernel.org \
    --cc=miaoxie@huawei.com \
    --cc=zhaohongjiang@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.