[Gluster-devel] a link issue maybe introduced in a bug fix " Don't let NFS cache stat after writes"
Niels de Vos
ndevos at redhat.com
Wed Jan 24 11:42:53 UTC 2018
On Wed, Jan 24, 2018 at 02:24:06PM +0530, Pranith Kumar Karampuri wrote:
> hi,
> In the same commit you mentioned earlier, there was this code
> earlier:
> -/* Returns 1 if the stat seems to be filled with zeroes. */
> -int
> -nfs_zero_filled_stat (struct iatt *buf)
> -{
> - if (!buf)
> - return 1;
> -
> - /* Do not use st_dev because it is transformed to store the xlator
> id
> - * in place of the device number. Do not use st_ino because by
> this time
> - * we've already mapped the root ino to 1 so it is not guaranteed
> to be
> - * 0.
> - */
> - if ((buf->ia_nlink == 0) && (buf->ia_ctime == 0))
> - return 1;
> -
> - return 0;
> -}
> -
> -
>
> I moved this to a common library function that can be used in afr as well.
> Why was it there in NFS? +Niels for answering that question.
Sorry, I dont know why that was done. It was introduced with the initial
gNFS implementation, long before I started to work with Gluster. The
only reference I have is this from
xlators/nfs/server/src/nfs3-helpers.c:nfs3_stat_to_post_op_attr()
371 /* Some performance translators return zero-filled stats when they
372 * do not have up-to-date attributes. Need to handle this by not
373 * returning these zeroed out attrs.
374 */
This may not be true for the current situation anymore.
HTH,
Niels
>
> If I give you a patch which will assert the error condition, would it be
> possible for you to figure out the first xlator which is unwinding the iatt
> with nlink count as zero but ctime as non-zero?
>
> On Wed, Jan 24, 2018 at 1:03 PM, Lian, George (NSB - CN/Hangzhou) <
> george.lian at nokia-sbell.com> wrote:
>
> > Hi, Pranith Kumar,
> >
> >
> >
> > Can you tell me while need set buf->ia_nlink to “0”in function
> > gf_zero_fill_stat(), which API or Application will care it?
> >
> > If I remove this line and also update corresponding in function
> > gf_is_zero_filled_stat,
> >
> > The issue seems gone, but I can’t confirm will lead to other issues.
> >
> >
> >
> > So could you please double check it and give your comments?
> >
> >
> >
> > My change is as the below:
> >
> >
> >
> > gf_boolean_t
> >
> > gf_is_zero_filled_stat (struct iatt *buf)
> >
> > {
> >
> > if (!buf)
> >
> > return 1;
> >
> >
> >
> > /* Do not use st_dev because it is transformed to store the xlator
> > id
> >
> > * in place of the device number. Do not use st_ino because by
> > this time
> >
> > * we've already mapped the root ino to 1 so it is not guaranteed
> > to be
> >
> > * 0.
> >
> > */
> >
> > // if ((buf->ia_nlink == 0) && (buf->ia_ctime == 0))
> >
> > if (buf->ia_ctime == )
> >
> > return 1;
> >
> >
> >
> > return 0;
> >
> > }
> >
> >
> >
> > void
> >
> > gf_zero_fill_stat (struct iatt *buf)
> >
> > {
> >
> > // buf->ia_nlink = 0;
> >
> > buf->ia_ctime = 0;
> >
> > }
> >
> >
> >
> > Thanks & Best Regards
> >
> > George
> >
> > *From:* Lian, George (NSB - CN/Hangzhou)
> > *Sent:* Friday, January 19, 2018 10:03 AM
> > *To:* Pranith Kumar Karampuri <pkarampu at redhat.com>; Zhou, Cynthia (NSB -
> > CN/Hangzhou) <cynthia.zhou at nokia-sbell.com>
> > *Cc:* Li, Deqian (NSB - CN/Hangzhou) <deqian.li at nokia-sbell.com>;
> > Gluster-devel at gluster.org; Sun, Ping (NSB - CN/Hangzhou) <
> > ping.sun at nokia-sbell.com>
> >
> > *Subject:* RE: [Gluster-devel] a link issue maybe introduced in a bug fix
> > " Don't let NFS cache stat after writes"
> >
> >
> >
> > Hi,
> >
> > >>> Cool, this works for me too. Send me a mail off-list once you are
> > available and we can figure out a way to get into a call and work on this.
> >
> >
> >
> > Have you reproduced the issue per the step I listed in
> > https://bugzilla.redhat.com/show_bug.cgi?id=1531457 and last mail?
> >
> >
> >
> > If not, I would like you could try it yourself , which the difference
> > between yours and mine is just create only 2 bricks instead of 6 bricks.
> >
> >
> >
> > And Cynthia could have a session with you if you needed when I am not
> > available in next Monday and Tuesday.
> >
> >
> >
> > Thanks & Best Regards,
> >
> > George
> >
> >
> >
> > *From:* gluster-devel-bounces at gluster.org [mailto:gluster-devel-bounces@
> > gluster.org <gluster-devel-bounces at gluster.org>] *On Behalf Of *Pranith
> > Kumar Karampuri
> > *Sent:* Thursday, January 18, 2018 6:03 PM
> > *To:* Lian, George (NSB - CN/Hangzhou) <george.lian at nokia-sbell.com>
> > *Cc:* Zhou, Cynthia (NSB - CN/Hangzhou) <cynthia.zhou at nokia-sbell.com>;
> > Li, Deqian (NSB - CN/Hangzhou) <deqian.li at nokia-sbell.com>;
> > Gluster-devel at gluster.org; Sun, Ping (NSB - CN/Hangzhou) <
> > ping.sun at nokia-sbell.com>
> > *Subject:* Re: [Gluster-devel] a link issue maybe introduced in a bug fix
> > " Don't let NFS cache stat after writes"
> >
> >
> >
> >
> >
> >
> >
> > On Thu, Jan 18, 2018 at 12:17 PM, Lian, George (NSB - CN/Hangzhou) <
> > george.lian at nokia-sbell.com> wrote:
> >
> > Hi,
> >
> > >>>I actually tried it with replica-2 and replica-3 and then distributed
> > replica-2 before replying to the earlier mail. We can have a debugging
> > session if you are okay with it.
> >
> >
> >
> > It is fine if you can’t reproduce the issue in your ENV.
> >
> > And I has attached the detail reproduce log in the Bugzilla FYI
> >
> >
> >
> > But I am sorry I maybe OOO at Monday and Tuesday next week, so debug
> > session will be fine to me at next Wednesday.
> >
> >
> >
> > Cool, this works for me too. Send me a mail off-list once you are
> > available and we can figure out a way to get into a call and work on this.
> >
> >
> >
> >
> >
> >
> >
> > Paste the detail reproduce log FYI here:
> >
> > *root at ubuntu:~# gluster peer probe ubuntu*
> >
> > *peer probe: success. Probe on localhost not needed*
> >
> > *root at ubuntu:~# gluster v create test replica 2 ubuntu:/home/gfs/b1
> > ubuntu:/home/gfs/b2 force*
> >
> > *volume create: test: success: please start the volume to access data*
> >
> > *root at ubuntu:~# gluster v start test*
> >
> > *volume start: test: success*
> >
> > *root at ubuntu:~# gluster v info test*
> >
> >
> >
> > *Volume Name: test*
> >
> > *Type: Replicate*
> >
> > *Volume ID: fef5fca3-81d9-46d3-8847-74cde6f701a5*
> >
> > *Status: Started*
> >
> > *Snapshot Count: 0*
> >
> > *Number of Bricks: 1 x 2 = 2*
> >
> > *Transport-type: tcp*
> >
> > *Bricks:*
> >
> > *Brick1: ubuntu:/home/gfs/b1*
> >
> > *Brick2: ubuntu:/home/gfs/b2*
> >
> > *Options Reconfigured:*
> >
> > *transport.address-family: inet*
> >
> > *nfs.disable: on*
> >
> > *performance.client-io-threads: off*
> >
> > *root at ubuntu:~# gluster v status*
> >
> > *Status of volume: test*
> >
> > *Gluster process TCP Port RDMA Port Online
> > Pid*
> >
> >
> > *------------------------------------------------------------------------------*
> >
> > *Brick ubuntu:/home/gfs/b1 49152 0 Y
> > 7798*
> >
> > *Brick ubuntu:/home/gfs/b2 49153 0 Y
> > 7818*
> >
> > *Self-heal Daemon on localhost N/A N/A Y
> > 7839*
> >
> >
> >
> > *Task Status of Volume test*
> >
> >
> > *------------------------------------------------------------------------------*
> >
> > *There are no active volume tasks*
> >
> >
> >
> >
> >
> > *root at ubuntu:~# gluster v set test cluster.consistent-metadata on*
> >
> > *volume set: success*
> >
> >
> >
> > *root at ubuntu:~# ls /mnt/test*
> >
> > *ls: cannot access '/mnt/test': No such file or directory*
> >
> > *root at ubuntu:~# mkdir -p /mnt/test*
> >
> > *root at ubuntu:~# mount -t glusterfs ubuntu:/test /mnt/test*
> >
> >
> >
> > *root at ubuntu:~# cd /mnt/test*
> >
> > *root at ubuntu:/mnt/test# echo "abc">aaa*
> >
> > *root at ubuntu:/mnt/test# cp aaa bbb;link bbb ccc*
> >
> >
> >
> > *root at ubuntu:/mnt/test# kill -9 7818*
> >
> > *root at ubuntu:/mnt/test# cp aaa ddd;link ddd eee*
> >
> > *link: cannot create link 'eee' to 'ddd': No such file or directory*
> >
> >
> >
> >
> >
> > Best Regards,
> >
> > George
> >
> >
> >
> > *From:* gluster-devel-bounces at gluster.org [mailto:gluster-devel-bounces@
> > gluster.org] *On Behalf Of *Pranith Kumar Karampuri
> > *Sent:* Thursday, January 18, 2018 2:40 PM
> >
> >
> > *To:* Lian, George (NSB - CN/Hangzhou) <george.lian at nokia-sbell.com>
> > *Cc:* Zhou, Cynthia (NSB - CN/Hangzhou) <cynthia.zhou at nokia-sbell.com>;
> > Gluster-devel at gluster.org; Li, Deqian (NSB - CN/Hangzhou) <
> > deqian.li at nokia-sbell.com>; Sun, Ping (NSB - CN/Hangzhou) <
> > ping.sun at nokia-sbell.com>
> > *Subject:* Re: [Gluster-devel] a link issue maybe introduced in a bug fix
> > " Don't let NFS cache stat after writes"
> >
> >
> >
> >
> >
> >
> >
> > On Thu, Jan 18, 2018 at 6:33 AM, Lian, George (NSB - CN/Hangzhou) <
> > george.lian at nokia-sbell.com> wrote:
> >
> > Hi,
> >
> > I suppose the brick numbers in your testing is six, and you just shut down
> > the 3 process.
> >
> > When I reproduce the issue, I only create a replicate volume with 2
> > bricks, only let ONE brick working and set cluster.consistent-metadata on,
> >
> > With this 2 test condition, the issue could 100% reproducible.
> >
> >
> >
> > Hi,
> >
> > I actually tried it with replica-2 and replica-3 and then
> > distributed replica-2 before replying to the earlier mail. We can have a
> > debugging session if you are okay with it.
> >
> > I am in the middle of a customer issue myself(That is the reason for this
> > delay :-( ) and thinking of wrapping it up early next week. Would that be
> > fine with you?
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > 16:44:28 :) ⚡ gluster v status
> >
> > Status of volume: r2
> >
> > Gluster process TCP Port RDMA Port Online
> > Pid
> >
> > ------------------------------------------------------------
> > ------------------
> >
> > Brick localhost.localdomain:/home/gfs/r2_0 49152 0 Y
> > 5309
> >
> > Brick localhost.localdomain:/home/gfs/r2_1 49154 0 Y
> > 5330
> >
> > Brick localhost.localdomain:/home/gfs/r2_2 49156 0 Y
> > 5351
> >
> > Brick localhost.localdomain:/home/gfs/r2_3 49158 0 Y
> > 5372
> >
> > Brick localhost.localdomain:/home/gfs/r2_4 49159 0 Y
> > 5393
> >
> > Brick localhost.localdomain:/home/gfs/r2_5 49160 0 Y
> > 5414
> >
> > Self-heal Daemon on localhost N/A N/A Y
> > 5436
> >
> >
> >
> > Task Status of Volume r2
> >
> > ------------------------------------------------------------
> > ------------------
> >
> > There are no active volume tasks
> >
> >
> >
> > root at dhcp35-190 - ~
> >
> > 16:44:38 :) ⚡ kill -9 5309 5351 5393
> >
> >
> >
> > Best Regards,
> >
> > George
> >
> > *From:* gluster-devel-bounces at gluster.org [mailto:gluster-devel-bounces@
> > gluster.org] *On Behalf Of *Pranith Kumar Karampuri
> > *Sent:* Wednesday, January 17, 2018 7:27 PM
> > *To:* Lian, George (NSB - CN/Hangzhou) <george.lian at nokia-sbell.com>
> > *Cc:* Li, Deqian (NSB - CN/Hangzhou) <deqian.li at nokia-sbell.com>;
> > Gluster-devel at gluster.org; Zhou, Cynthia (NSB - CN/Hangzhou) <
> > cynthia.zhou at nokia-sbell.com>; Sun, Ping (NSB - CN/Hangzhou) <
> > ping.sun at nokia-sbell.com>
> >
> >
> > *Subject:* Re: [Gluster-devel] a link issue maybe introduced in a bug fix
> > " Don't let NFS cache stat after writes"
> >
> >
> >
> >
> >
> >
> >
> > On Mon, Jan 15, 2018 at 1:55 PM, Pranith Kumar Karampuri <
> > pkarampu at redhat.com> wrote:
> >
> >
> >
> >
> >
> > On Mon, Jan 15, 2018 at 8:46 AM, Lian, George (NSB - CN/Hangzhou) <
> > george.lian at nokia-sbell.com> wrote:
> >
> > Hi,
> >
> >
> >
> > Have you reproduced this issue? If yes, could you please confirm whether
> > it is an issue or not?
> >
> >
> >
> > Hi,
> >
> > I tried recreating this on my laptop and on both master and 3.12
> > and I am not able to recreate the issue :-(.
> >
> > Here is the execution log: https://paste.fedoraproject.org/paste/-
> > csXUKrwsbrZAVW1KzggQQ
> >
> > Since I was doing this on my laptop, I changed shutting down of the
> > replica to killing the brick process to simulate this test.
> >
> > Let me know if I missed something.
> >
> >
> >
> >
> >
> > Sorry, I am held up with some issue at work, so I think I will get some
> > time day after tomorrow to look at this. In the mean time I am adding more
> > people who know about afr to see if they get a chance to work on this
> > before me.
> >
> >
> >
> >
> >
> > And if it is an issue, do you have any solution for this issue?
> >
> >
> >
> > Thanks & Best Regards,
> >
> > George
> >
> >
> >
> > *From:* Lian, George (NSB - CN/Hangzhou)
> > *Sent:* Thursday, January 11, 2018 2:01 PM
> > *To:* Pranith Kumar Karampuri <pkarampu at redhat.com>
> > *Cc:* Zhou, Cynthia (NSB - CN/Hangzhou) <cynthia.zhou at nokia-sbell.com>;
> > Gluster-devel at gluster.org; Li, Deqian (NSB - CN/Hangzhou) <
> > deqian.li at nokia-sbell.com>; Sun, Ping (NSB - CN/Hangzhou) <
> > ping.sun at nokia-sbell.com>
> > *Subject:* RE: [Gluster-devel] a link issue maybe introduced in a bug fix
> > " Don't let NFS cache stat after writes"
> >
> >
> >
> > Hi,
> >
> >
> >
> > Please see detail test step on https://bugzilla.redhat.com/
> > show_bug.cgi?id=1531457
> >
> >
> >
> > How reproducible:
> >
> >
> >
> >
> >
> > Steps to Reproduce:
> >
> > 1.create a volume name "test" with replicated
> >
> > 2.set volume option cluster.consistent-metadata with on:
> >
> > gluster v set test cluster.consistent-metadata on
> >
> > 3. mount volume test on client on /mnt/test
> >
> > 4. create a file aaa size more than 1 byte
> >
> > echo "1234567890" >/mnt/test/aaa
> >
> > 5. shutdown a replicat node, let's say sn-1, only let sn-0 worked
> >
> > 6. cp /mnt/test/aaa /mnt/test/bbb; link /mnt/test/bbb /mnt/test/ccc
> >
> >
> >
> >
> >
> > BRs
> >
> > George
> >
> >
> >
> > *From:* gluster-devel-bounces at gluster.org [mailto:gluster-devel-bounces@
> > gluster.org <gluster-devel-bounces at gluster.org>] *On Behalf Of *Pranith
> > Kumar Karampuri
> > *Sent:* Thursday, January 11, 2018 12:39 PM
> > *To:* Lian, George (NSB - CN/Hangzhou) <george.lian at nokia-sbell.com>
> > *Cc:* Zhou, Cynthia (NSB - CN/Hangzhou) <cynthia.zhou at nokia-sbell.com>;
> > Gluster-devel at gluster.org; Li, Deqian (NSB - CN/Hangzhou) <
> > deqian.li at nokia-sbell.com>; Sun, Ping (NSB - CN/Hangzhou) <
> > ping.sun at nokia-sbell.com>
> > *Subject:* Re: [Gluster-devel] a link issue maybe introduced in a bug fix
> > " Don't let NFS cache stat after writes"
> >
> >
> >
> >
> >
> >
> >
> > On Thu, Jan 11, 2018 at 6:35 AM, Lian, George (NSB - CN/Hangzhou) <
> > george.lian at nokia-sbell.com> wrote:
> >
> > Hi,
> >
> > >>> In which protocol are you seeing this issue? Fuse/NFS/SMB?
> >
> > It is fuse, within mountpoint by “mount -t glusterfs …“ command.
> >
> >
> >
> > Could you let me know the test you did so that I can try to re-create and
> > see what exactly is going on?
> >
> > Configuration of the volume and the steps to re-create the issue you are
> > seeing would be helpful in debugging the issue further.
> >
> >
> >
> >
> >
> > Thanks & Best Regards,
> >
> > George
> >
> >
> >
> > *From:* gluster-devel-bounces at gluster.org [mailto:gluster-devel-bounces@
> > gluster.org] *On Behalf Of *Pranith Kumar Karampuri
> > *Sent:* Wednesday, January 10, 2018 8:08 PM
> > *To:* Lian, George (NSB - CN/Hangzhou) <george.lian at nokia-sbell.com>
> > *Cc:* Zhou, Cynthia (NSB - CN/Hangzhou) <cynthia.zhou at nokia-sbell.com>;
> > Zhong, Hua (NSB - CN/Hangzhou) <hua.zhong at nokia-sbell.com>; Li, Deqian
> > (NSB - CN/Hangzhou) <deqian.li at nokia-sbell.com>; Gluster-devel at gluster.org;
> > Sun, Ping (NSB - CN/Hangzhou) <ping.sun at nokia-sbell.com>
> > *Subject:* Re: [Gluster-devel] a link issue maybe introduced in a bug fix
> > " Don't let NFS cache stat after writes"
> >
> >
> >
> >
> >
> >
> >
> > On Wed, Jan 10, 2018 at 11:09 AM, Lian, George (NSB - CN/Hangzhou) <
> > george.lian at nokia-sbell.com> wrote:
> >
> > Hi, Pranith Kumar,
> >
> >
> >
> > I has create a bug on Bugzilla https://bugzilla.redhat.com/
> > show_bug.cgi?id=1531457
> >
> > After my investigation for this link issue, I suppose your changes on
> > afr-dir-write.c with issue " Don't let NFS cache stat after writes" , your
> > fix is like:
> >
> > --------------------------------------
> >
> > if (afr_txn_nothing_failed (frame, this)) {
> >
> > /*if it did pre-op, it will do post-op changing
> > ctime*/
> >
> > if (priv->consistent_metadata &&
> >
> > afr_needs_changelog_update (local))
> >
> > afr_zero_fill_stat (local);
> >
> > local->transaction.unwind (frame, this);
> >
> > }
> >
> > In the above fix, it set the ia_nlink to ‘0’ if option
> > consistent-metadata is set to “on”.
> >
> > And hard link a file with which just created will lead to an error, and
> > the error is caused in kernel function “vfs_link”:
> >
> > if (inode->i_nlink == 0 && !(inode->i_state & I_LINKABLE))
> >
> > error = -ENOENT;
> >
> >
> >
> > could you please have a check and give some comments here?
> >
> >
> >
> > When stat is "zero filled", understanding is that the higher layer
> > protocol doesn't send stat value to the kernel and a separate lookup is
> > sent by the kernel to get the latest stat value. In which protocol are you
> > seeing this issue? Fuse/NFS/SMB?
> >
> >
> >
> >
> >
> > Thanks & Best Regards,
> >
> > George
> >
> >
> >
> >
> > --
> >
> > Pranith
> >
> >
> >
> >
> > --
> >
> > Pranith
> >
> >
> >
> >
> > --
> >
> > Pranith
> >
> >
> >
> >
> > --
> >
> > Pranith
> >
> >
> >
> >
> > --
> >
> > Pranith
> >
> >
> >
> >
> > --
> >
> > Pranith
> >
>
>
>
> --
> Pranith
More information about the Gluster-devel
mailing list