On Wed, Dec 31, 2014 at 11:25 PM, Xavier Hernandez <xhernandez@xxxxxxxxxx> wrote:
On 27.12.2014 13:43, lidi@xxxxxxxxxxxxx wrote:
I tracked this problem, and found that the loc.parent and loc.pargfid are all null in the call sequences below:
ec_manager_writev() -> ec_get_size_version() -> ec_lookup(). This can cause server_resolve() return an EINVAL.
A replace-brick will cause all opened fd and inode table recreate, but ec_lookup() get the loc from fd->_ctx.
So loc.parent and loc.pargfid are missing while fd changed. Other xlators always do a lookup from root
directory, so never cause this problem. It seems that a recursive lookup from root directory may address this
issue.EINVAL error is returned by protocol/server when it tries to resolve an inode based on a loc. If loc's 'name' field is not NULL nor empty, it tries to resolve the inode based on <pargfid>/<name>. The problem here is that pargfid is 00...00.
To solve this issue I've modified ec_loc_setup_parent() so that it clears loc's 'name' if parent inode cannot be determined. This forces protocol/server to resolve the inode based on <gfid>, which is valid and can be resolved successfully.
However this doesn't fully solve the bug. After solving this issue, I get an EIO error. Further investigations seems to indicate that this is caused by a locking problem caused by an incorrect management of ESTALE when the brick is replaced.
ESTALE indicates either any of the following situations:
1. In the case of named-lookup (loc containing <pargfid>/<name>), <pargfid> is not present. Which means parent is not present on the brick
2. In the case of nameless lookup (loc containing only <gfid> of the file), file/directory represented by gfid is not present on brick.
Which among the above two scenarios is your case?
>
I'll upload a patch shortly to solve these issues.Xavi
----- 原邮件信息 -----
发件人：Raghavendra Gowdappa
发送时间：14-12-24 21:48:56
收件人：Xavier Hernandez
抄送人：Gluster Devel
主题：Re: Problems with graph switch in disperse
Do you know the origins of EIO? fuse-bridge only fails a lookup fop with EIO (when NULL gfid is received in a successful lookup reply). So, there might be other xlator which is sending EIO.
----- Original Message -----
> From: "Xavier Hernandez"
> To: "Gluster Devel"
> Sent: Wednesday, December 24, 2014 6:25:17 PM
> Subject: [Gluster-devel] Problems with graph switch in disperse
>
> Hi,
>
> I'm experiencing a problem when gluster graph is changed as a result of
> a replace-brick operation (probably with any other operation that
> changes the graph) while the client is also doing other tasks, like
> writing a file.
>
> When operation starts, I see that the replaced brick is disconnected,
> but writes continue working normally with one brick less.
>
> At some point, another graph is created and comes online. Remaining
> bricks on the old graph are disconnected and the old graph is destroyed.
> I see how new write requests are sent to the new graph.
>
> This seems correct. However there's a point where I see this:
>
> [2014-12-24 11:29:58.541130] T [fuse-bridge.c:2305:fuse_write_resume]
> 0-glusterfs-fuse: 2234: WRITE (0x16dcf3c, size=131072, offset=255721472)
> [2014-12-24 11:29:58.541156] T [ec-helpers.c:101:ec_trace] 2-ec:
> WIND(INODELK) 0x7f8921b7a9a4(0x7f8921b78e14) [refs=5, winds=3, jobs=1]
> frame=0x7f8932e92c38/0x7f8932e9e6b0, min/exp=3/3, err=0 state=1
> {111:000:000} idx=0
> [2014-12-24 11:29:58.541292] T [rpc-clnt.c:1384:rpc_clnt_record]
> 2-patchy-client-0: Auth Info: pid: 0, uid: 0, gid: 0, owner:
> d025e932897f0000
> [2014-12-24 11:29:58.541296] T [io-cache.c:133:ioc_inode_flush]
> 2-patchy-io-cache: locked inode(0x16d2810)
> [2014-12-24 11:29:58.541354] T
> [rpc-clnt.c:1241:rpc_clnt_record_build_header] 2-rpc-clnt: Request
> fraglen 152, payload: 84, rpc hdr: 68
> [2014-12-24 11:29:58.541408] T [io-cache.c:137:ioc_inode_flush]
> 2-patchy-io-cache: unlocked inode(0x16d2810)
> [2014-12-24 11:29:58.541493] T [io-cache.c:133:ioc_inode_flush]
> 2-patchy-io-cache: locked inode(0x16d2810)
> [2014-12-24 11:29:58.541536] T [io-cache.c:137:ioc_inode_flush]
> 2-patchy-io-cache: unlocked inode(0x16d2810)
> [2014-12-24 11:29:58.541537] T [rpc-clnt.c:1577:rpc_clnt_submit]
> 2-rpc-clnt: submitted request (XID: 0x17 Program: GlusterFS 3.3,
> ProgVers: 330, Proc: 29) to rpc-transport (patchy-client-0)
> [2014-12-24 11:29:58.541646] W [fuse-bridge.c:2271:fuse_writev_cbk]
> 0-glusterfs-fuse: 2234: WRITE => -1 (Input/output error)
>
> It seems that fuse still has a write request pending for graph 0. It is
> resumed but it returns EIO without calling the xlator stack (operations
> seen between the two log messages are from other operations and they are
> sent to graph 2). I'm not sure why this happens and how I should aviod this.
>
> I tried the same scenario with replicate and it seems to work, so there
> must be something wrong in disperse, but I don't see where the problem
> could be.
>
> Any ideas ?
>
> Thanks,
>
> Xavi
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--
Raghavendra G
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