[pnfs] [PATCH] nfs41: Correctly use new session in exception handling
William A. (Andy) Adamson
andros at citi.umich.edu
Tue May 27 14:10:53 EDT 2008
I turned all debug off on both client and server, still was unable to
reproduce the problem, got the same results as below.... :(
-->Andy
On Tue, May 27, 2008 at 12:53 PM, Benny Halevy <bhalevy at panasas.com> wrote:
> I forgot to mention that I couldn't reproduce this with debug printing
> on...
> Did you try with nfsd_debug by any chance?
> Benny
>
> William A. (Andy) Adamson wrote:
> > Hi Benny
> >
> > I can't reproduce the problem. Using todays tree, origin/nfs41 branch
> > on client and server, I attempt to mount a non-existing path: the
> > server does not export a /unix4.
> >
> > mount -t nfs4 192.168.1.105:/unix4 /mnt
> >
> > What I see is a successful EXCHANGE_ID, CREATE_SESSION (with a
> > successful callback channel established), SEQ/PUTROOTFH/GETFH/GETATTR,
> > a couple of more successful SEQ/PUTFH/GETATTRS to establish the root,
> > then a PUTFH/LOOKUP/GETATTR for /unix4 that fails, followed by a
> > DESTROY_SESSION.
> >
> > Are you doing something different?
> >
> > Here is my /etc/exports file:
> >
> > /var/lib/nfs/v4root *(fsid=0,rw,insecure,no_root_squash,nohide,crossmnt)
> > /var/lib/nfs/v4root/spnfs *(rw,insecure,no_root_squash,nohide,crossmnt)
> > /var/lib/nfs/v4root/unix *(rw,insecure,no_root_squash,nohide,crossmnt)
> >
> > with
> > /export on /var/lib/nfs/v4root/spnfs type none (rw,bind)
> > /unix on /var/lib/nfs/v4root/unix type none (rw,bind)
> >
> >
> > -->Andy
> >
> > On Sun, May 25, 2008 at 1:19 PM, Benny Halevy <bhalevy at panasas.com
> > <mailto:bhalevy at panasas.com>> wrote:
> >
> > Andy, I think that this approach is better than what we had
> > before but bare in mind that it breaks the server when
> > the exported path is not found.
> >
> > I get the following oops when the client mounts a non-existing path:
> > (with this patch applied)
> >
> > May 25 18:48:01 bh-testlin1 kernel: BUG: unable to handle kernel
> > NULL pointer dereference at 00000000000000a0
> > May 25 18:48:01 bh-testlin1 kernel: IP: [<ffffffff88263233>]
> > :sunrpc:bc_send_request+0xc0/0x1e2
> > May 25 18:48:01 bh-testlin1 kernel: PGD 78800067 PUD 78811067 PMD 0
> > May 25 18:48:01 bh-testlin1 kernel: Oops: 0000 [1] SMP
> > May 25 18:48:01 bh-testlin1 kernel: CPU 0
> > May 25 18:48:01 bh-testlin1 kernel: Modules linked in: nfsd
> > auth_rpcgss exportfs autofs4 nfs lockd nfs_acl sunrpc ipv6
> > dm_mirror dm_multipath dm_mod video output sbs sbshc battery ac
> > kvm_amd kvm snd_hda_intel button snd_pcm k8temp i2c_nforce2
> > i2c_core snd_timer pcspkr snd_page_alloc snd_hwdep sr_mod snd
> > soundcore hwmon forcedeth serio_raw sg cdrom pata_amd ata_generic
> > pata_acpi sata_nv libata sd_mod scsi_mod ext3 jbd mbcache ehci_hcd
> > ohci_hcd uhci_hcd [last unloaded: scsi_wait_scan]
> > May 25 18:48:01 bh-testlin1 kernel: Pid: 3271, comm: nfs4_cb_probe
> > Not tainted 2.6.25-nfs41 #39
> > May 25 18:48:01 bh-testlin1 kernel: RIP: 0010:[<ffffffff88263233>]
> > [<ffffffff88263233>] :sunrpc:bc_send_request+0xc0/0x1e2
> > May 25 18:48:01 bh-testlin1 kernel: RSP: 0018:ffff810078991d10
> > EFLAGS: 00010246
> > May 25 18:48:01 bh-testlin1 kernel: RAX: 0000000000000000 RBX:
> > 0000000000000074 RCX: 0000000000000005
> > May 25 18:48:01 bh-testlin1 kernel: RDX: ffff8100788ec008 RSI:
> > 0000000000000057 RDI: ffff8100788ec008
> > May 25 18:48:01 bh-testlin1 kernel: RBP: ffff8100788ec008 R08:
> > ffff81007880eb60 R09: ffff81007880eb20
> > May 25 18:48:01 bh-testlin1 kernel: R10: 0000000000000000 R11:
> > ffffffff88267550 R12: ffff81007893e000
> > May 25 18:48:01 bh-testlin1 kernel: R13: ffff81007893e008 R14:
> > 0000000000000000 R15: ffff8100798ee340
> > May 25 18:48:01 bh-testlin1 kernel: FS: 00007f05577b26f0(0000)
> > GS:ffffffff8139c000(0000) knlGS:0000000000000000
> > May 25 18:48:01 bh-testlin1 kernel: CS: 0010 DS: 0018 ES: 0018
> > CR0: 000000008005003b
> > May 25 18:48:01 bh-testlin1 kernel: CR2: 00000000000000a0 CR3:
> > 0000000078810000 CR4: 00000000000006e0
> > May 25 18:48:01 bh-testlin1 kernel: DR0: 0000000000000000 DR1:
> > 0000000000000000 DR2: 0000000000000000
> > May 25 18:48:01 bh-testlin1 kernel: DR3: 0000000000000000 DR6:
> > 00000000ffff0ff0 DR7: 0000000000000400
> > May 25 18:48:01 bh-testlin1 kernel: Process nfs4_cb_probe (pid:
> > 3271, threadinfo ffff810078990000, task ffff810076157360)
> > May 25 18:48:01 bh-testlin1 kernel: Stack: 00000000ffffffff
> > ffff810079d1c258 0000000000000286 0000000000000000
> > May 25 18:48:01 bh-testlin1 kernel: 0000000000000074
> > ffff81007880eb20 ffff81007880e800 ffff81007893e000
> > May 25 18:48:01 bh-testlin1 kernel: ffff81007e1f0200
> > ffff81007893e0b8 0000000000000000 ffffffff8826197b
> > May 25 18:48:01 bh-testlin1 kernel: Call Trace:
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff8826197b>] ?
> > :sunrpc:xprt_transmit+0xd3/0x1c1
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff8832873c>] ?
> > :nfsd:nfs4_xdr_enc_cb_null+0x0/0x50
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff8825f4ab>] ?
> > :sunrpc:call_transmit+0x200/0x23f
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff88265f3f>] ?
> > :sunrpc:__rpc_execute+0x7b/0x21a
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff8825fc62>] ?
> > :sunrpc:rpc_run_task+0x4f/0x56
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff8825fcfe>] ?
> > :sunrpc:rpc_call_sync+0x3e/0x5b
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff88328e8f>] ?
> > :nfsd:do_probe_callback+0x250/0x2c6
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff88328c3f>] ?
> > :nfsd:do_probe_callback+0x0/0x2c6
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff81043ddd>] ?
> > kthread+0x47/0x76
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff8100cac8>] ?
> > child_rip+0xa/0x12
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff81043d96>] ?
> > kthread+0x0/0x76
> > May 25 18:48:01 bh-testlin1 kernel: [<ffffffff8100cabe>] ?
> > child_rip+0x0/0x12
> > May 25 18:48:01 bh-testlin1 kernel:
> > May 25 18:48:01 bh-testlin1 kernel:
> > May 25 18:48:01 bh-testlin1 kernel: Code: 49 8b 5d 08 48 63 c7 c7
> > 44 24 14 00 80 00 00 48 39 d8 b8 00
> > 00 00 00 0f 45 44 24 14 89 44 24 14 48 8b 6d 08 49 8b 47 10 48 89
> > ef <4c> 8b a0 a0 00 00 00 e8 61 f2
> > db f8 48 c1 e8 0c 89 ea 48 be 00
> > May 25 18:48:01 bh-testlin1 kernel: RIP [<ffffffff88263233>]
> > :sunrpc:bc_send_request+0xc0/0x1e2
> > May 25 18:48:01 bh-testlin1 kernel: RSP <ffff810078991d10>
> > May 25 18:48:01 bh-testlin1 kernel: CR2: 00000000000000a0
> > May 25 18:48:01 bh-testlin1 kernel: ---[ end trace
> > e76d1803ca214c10 ]---
> >
> > On May. 23, 2008, 21:29 +0300, andros at netapp.com
> > <mailto:andros at netapp.com> wrote:
> > > From: Andy Adamson <andros at netapp.com <mailto:andros at netapp.com>>
> > >
> > > We will need to handle several layers of session recovery
> > depending on the
> > > error. As a last resort, we will need to use the big hammer;
> destroy
> > > an existing session and create a new one.
> > >
> > > The current code creates a new session without destroying the
> > old one.
> > > Destroy the existing session and initialize a new session before
> > calling
> > > nfs41_recover_session_sync.
> > >
> > > Signed-off-by: Andy Adamson<andros at netapp.com
> > <mailto:andros at netapp.com>>
> > > ---
> > > fs/nfs/client.c | 3 ++-
> > > fs/nfs/internal.h | 4 ++++
> > > fs/nfs/nfs41_session_recovery.c | 25
> > +++++++++++++++++++++++++
> > > fs/nfs/nfs4proc.c | 4 ++--
> > > include/linux/nfs41_session_recovery.h | 1 +
> > > 5 files changed, 34 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/fs/nfs/client.c b/fs/nfs/client.c
> > > index a014f32..d1161ef 100644
> > > --- a/fs/nfs/client.c
> > > +++ b/fs/nfs/client.c
> > > @@ -1116,7 +1116,7 @@ error:
> > > /*
> > > * Allocate and initialize a session if required, including its
> > backchannel.
> > > */
> > > -static int nfs4_init_session(struct nfs_client *clp, struct
> > nfs4_session **spp,
> > > +int nfs4_init_session(struct nfs_client *clp, struct
> > nfs4_session **spp,
> > > struct rpc_clnt *clnt)
> > > {
> > > int error = 0;
> > > @@ -1148,6 +1148,7 @@ static int nfs4_init_session(struct
> > nfs_client *clp, struct nfs4_session **spp,
> > > }
> > > return error;
> > > }
> > > +EXPORT_SYMBOL(nfs4_init_session);
> > > #endif /* CONFIG_NFS_V4_1 */
> > >
> > > /*
> > > diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> > > index 22228bc..735dbb7 100644
> > > --- a/fs/nfs/internal.h
> > > +++ b/fs/nfs/internal.h
> > > @@ -66,6 +66,10 @@ struct nfs_parsed_mount_data {
> > > };
> > >
> > > /* client.c */
> > > +#ifdef CONFIG_NFS_V4_1
> > > +extern int nfs4_init_session(struct nfs_client *, struct
> > nfs4_session **,
> > > + struct rpc_clnt *);
> > > +#endif /* CONFIG_NFS_V4_1 */
> > > extern struct rpc_program nfs_program;
> > >
> > > extern void nfs_put_client(struct nfs_client *);
> > > diff --git a/fs/nfs/nfs41_session_recovery.c
> > b/fs/nfs/nfs41_session_recovery.c
> > > index 46ddb55..cf02704 100644
> > > --- a/fs/nfs/nfs41_session_recovery.c
> > > +++ b/fs/nfs/nfs41_session_recovery.c
> > > @@ -22,6 +22,7 @@
> > > #include <linux/nfs_fs_sb.h>
> > > #include <linux/nfs41_session_recovery.h>
> > > #include "nfs4_fs.h"
> > > +#include "internal.h"
> > >
> > > #define NFSDBG_FACILITY NFSDBG_PROC
> > >
> > > @@ -191,4 +192,28 @@ int nfs41_recover_session_sync(struct
> > rpc_clnt *clnt, struct nfs_client *clp,
> > > }
> > > EXPORT_SYMBOL(nfs41_recover_session_sync);
> > >
> > > +/*
> > > + * nfs41_new_session()
> > > + *
> > > + * Big Hammer. Destroy existing session and create a new session
> > > + */
> > > +int nfs41_new_session(struct nfs_server *server)
> > > +{
> > > + int ret;
> > > +
> > > + dprintk(" --> %s\n", __func__);
> > > +
> > > + nfs4_put_session(&server->session);
> > > + ret = nfs4_init_session(server->nfs_client, &server->session,
> > > + server->client);
> > > + if (ret)
> > > + goto out;
> > > + ret = nfs41_recover_session_sync(server->client,
> > server->nfs_client,
> > > + server->session);
> > > +out:
> > > + dprintk(" <-- %s returns %d\n", __func__, ret);
> > > + return ret;
> > > +}
> > > +EXPORT_SYMBOL(nfs41_new_session);
> > > +
> > > #endif /* CONFIG_NFS_V4_1 */
> > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> > > index ccec2e0..9c12bfb 100644
> > > --- a/fs/nfs/nfs4proc.c
> > > +++ b/fs/nfs/nfs4proc.c
> > > @@ -3416,8 +3416,8 @@ static int nfs4_handle_exception(const
> > struct nfs_server *server, int errorcode,
> > > case -NFS4ERR_RETRY_UNCACHED_REP:
> > > case -NFS4ERR_TOO_MANY_OPS:
> > > case -NFS4ERR_OP_NOT_IN_SESSION:
> > > - ret =
> > nfs41_recover_session_sync(server->session->clnt,
> > > - server->nfs_client, server->session);
> > > +
> > > + ret = nfs41_new_session((struct nfs_server
> > *)server);
> > > if (!ret) {
> > > exception->retry = 1;
> > > break;
> > > diff --git a/include/linux/nfs41_session_recovery.h
> > b/include/linux/nfs41_session_recovery.h
> > > index 2f1df6f..5364b34 100644
> > > --- a/include/linux/nfs41_session_recovery.h
> > > +++ b/include/linux/nfs41_session_recovery.h
> > > @@ -36,6 +36,7 @@ int nfs41_set_session_valid(struct
> > nfs4_session *);
> > > int nfs41_recover_session(struct nfs_client *, struct
> > nfs4_session *);
> > > int nfs41_recover_session_sync(struct rpc_clnt *, struct
> > nfs_client *,
> > > struct nfs4_session *);
> > > +int nfs41_new_session(struct nfs_server *);
> > >
> > > #endif /* CONFIG_NFS_V4_1 */
> > > #endif /* __NFS41_SESSION_RECOVERY_H__ */
> >
> > _______________________________________________
> > pNFS mailing list
> > pNFS at linux-nfs.org <mailto:pNFS at linux-nfs.org>
> > http://linux-nfs.org/cgi-bin/mailman/listinfo/pnfs
> >
> >
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://linux-nfs.org/pipermail/pnfs/attachments/20080527/d615738a/attachment-0001.htm
More information about the pNFS
mailing list