Matt- Thanks for pursuing a permanent fix for this.
On Jan 5, 2009, at Jan 5, 2009, 8:13 PM, Matt Helsley wrote: > We can improve upon a workaround applied in commit > 63ffc23d307c9534c732edd87895e37b223004a3 ( > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=63ffc23d307c9534c732edd87895e37b223004a3 > > ) > > The original problem was: > > "On a system with nfs mounts, if a task unshares its mount namespace, > a oops can occur when the system is rebooted if the task is the last > to unreference the nfs mount. It will try to create a rpc request > using utsname() which has been invalidated by free_nsproxy()." > > Cedric worked around this by always using the initial uts namespace > for RPC. > Critically this workaround meant that RPC clients in uts namespaces > can never > report the changed nodename when utilizing RPC. > > Fix that by storing the nodename in the NFS server structure (part > of the NFS > super block) and, when an RPC client is operating on behalf of NFS, > reporting > that nodename. This solves the problem for NFS clients but leaves > any other > RPC users out in the cold. > > Rather than caching the nodename in the client structure RPC should > obtain the > nodename from RPC callers. It would then be up to those services > making RPC > calls to cache the nodename for as long as necessary -- somewhat > like this patch > does with NFS. Instead of having the RPC client call the consumer back, why can't you pass the nodename as an argument to each RPC call; say, via the rpc_message structure? > NOTE: Part of Cedric's workaround -- use of the initial uts > namespace -- is > still necessary because non-NFS RPC callers still rely on the > nodename cached > with the RPC client struct. In the long run I think it would be more useful to spell out where each consumer gets its nodename value, rather than having a convenient default value. A default would encourage exposing nodenames inappropriately due to sloppy coding and incorrect assumptions (on the developer's part) about a complex API. Where would NFSv4 callbacks get a nodename, for example? And what about rpcbind requests? > Thoughts? More comments below. > Signed-off-by: Matt Helsley <[email protected]> > Cc: Cedric Le Goater <[email protected]> > Cc: Linux Kernel Mailing List <[email protected]> > Cc: [email protected] > Cc: Trond Myklebust <[email protected]> > Cc: Chuck Lever <[email protected]> > Cc: Eric W. Biederman <[email protected]> > Cc: Linux Containers <[email protected]> > > --- > fs/lockd/clntproc.c | 16 +++++++++++++--- > fs/nfs/client.c | 6 ++++++ > fs/nfs/super.c | 6 ++++++ > include/linux/nfs_fs.h | 2 ++ > include/linux/nfs_fs_sb.h | 3 +++ > include/linux/sunrpc/clnt.h | 2 ++ > net/sunrpc/auth_unix.c | 13 ++++++++++++- > 7 files changed, 44 insertions(+), 4 deletions(-) > > Index: linux-2.6.28/include/linux/sunrpc/clnt.h > =================================================================== > --- linux-2.6.28.orig/include/linux/sunrpc/clnt.h > +++ linux-2.6.28/include/linux/sunrpc/clnt.h > @@ -19,6 +19,7 @@ > #include <asm/signal.h> > > struct rpc_inode; > +struct nfs_server; > > /* > * The high-level client handle > @@ -50,6 +51,7 @@ struct rpc_clnt { > > int cl_nodelen; /* nodename length */ > char cl_nodename[UNX_MAXNODENAME]; > + struct nfs_server *cl_nfs_server; This is a layering violation... I would rather avoid introducing new strong data structure dependencies on one of RPC's consumers. > char cl_pathname[30];/* Path in rpc_pipe_fs */ > struct vfsmount * cl_vfsmnt; > struct dentry * cl_dentry; /* inode */ > Index: linux-2.6.28/net/sunrpc/auth_unix.c > =================================================================== > --- linux-2.6.28.orig/net/sunrpc/auth_unix.c > +++ linux-2.6.28/net/sunrpc/auth_unix.c > @@ -12,6 +12,13 @@ > #include <linux/sunrpc/clnt.h> > #include <linux/sunrpc/auth.h> > > +#include <linux/nfs.h> > +#include <linux/nfs2.h> > +#include <linux/nfs3.h> > +#include <linux/nfs4.h> > +#include <linux/nfs_xdr.h> > +#include <linux/nfs_fs_sb.h> > + > #define NFS_NGROUPS 16 > > struct unx_cred { > @@ -151,7 +158,11 @@ unx_marshal(struct rpc_task *task, __be3 > /* > * Copy the UTS nodename captured when the client was created. > */ > - p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); > + if (clnt->cl_nfs_server) > + p = xdr_encode_array(p, clnt->cl_nfs_server->nodename, > + clnt->cl_nfs_server->nodelen); > + else > + p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); > > *p++ = htonl((u32) cred->uc_uid); > *p++ = htonl((u32) cred->uc_gid); > Index: linux-2.6.28/include/linux/nfs_fs_sb.h > =================================================================== > --- linux-2.6.28.orig/include/linux/nfs_fs_sb.h > +++ linux-2.6.28/include/linux/nfs_fs_sb.h > @@ -126,6 +126,9 @@ struct nfs_server { > u32 mountd_version; > unsigned short mountd_port; > unsigned short mountd_protocol; > + > + int nodelen; /* nodename length */ > + char nodename[UNX_MAXNODENAME]; > }; > > /* Server capabilities */ > Index: linux-2.6.28/fs/nfs/super.c > =================================================================== > --- linux-2.6.28.orig/fs/nfs/super.c > +++ linux-2.6.28/fs/nfs/super.c > @@ -51,6 +51,7 @@ > #include <linux/nfs_xdr.h> > #include <linux/magic.h> > #include <linux/parser.h> > +#include <linux/utsname.h> > > #include <asm/system.h> > #include <asm/uaccess.h> > @@ -1830,6 +1831,11 @@ static void nfs_fill_super(struct super_ > sb->s_time_gran = 1; > } > > + server->nodelen = strlen(utsname()->nodename); > + if (server->nodelen > UNX_MAXNODENAME) > + server->nodelen = UNX_MAXNODENAME; > + memcpy(server->nodename, utsname()->nodename, server->nodelen); > + > sb->s_op = &nfs_sops; > nfs_initialise_sb(sb); > } > Index: linux-2.6.28/fs/nfs/client.c > =================================================================== > --- linux-2.6.28.orig/fs/nfs/client.c > +++ linux-2.6.28/fs/nfs/client.c > @@ -25,10 +25,12 @@ > #include <linux/sunrpc/metrics.h> > #include <linux/sunrpc/xprtsock.h> > #include <linux/sunrpc/xprtrdma.h> > +#include <linux/sunrpc/svc.h> > #include <linux/nfs_fs.h> > #include <linux/nfs_mount.h> > #include <linux/nfs4_mount.h> > #include <linux/lockd/bind.h> > +#include <linux/lockd/lockd.h> > #include <linux/seq_file.h> > #include <linux/mount.h> > #include <linux/nfs_idmap.h> > @@ -47,6 +49,7 @@ > #include "internal.h" > > #define NFSDBG_FACILITY NFSDBG_CLIENT > +#define NLMDBG_FACILITY NLMDBG_CLIENT > > static DEFINE_SPINLOCK(nfs_client_lock); > static LIST_HEAD(nfs_client_list); > @@ -555,6 +558,7 @@ static void nfs_init_server_aclclient(st > > /* No errors! Assume that Sun nfsacls are supported */ > server->caps |= NFS_CAP_ACLS; > + server->client_acl->cl_nfs_server = server; > return; > > out_noacl: > @@ -673,6 +677,7 @@ static int nfs_init_server(struct nfs_se > goto error; > > server->nfs_client = clp; > + clp->cl_rpcclient->cl_nfs_server = server; > > /* Initialise the client representation from the mount data */ > server->flags = data->flags; > @@ -1035,6 +1040,7 @@ static int nfs4_set_client(struct nfs_se > goto error_put; > > server->nfs_client = clp; > + clp->cl_rpcclient->cl_nfs_server = server; > dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp); > return 0; > > Index: linux-2.6.28/fs/lockd/clntproc.c > =================================================================== > --- linux-2.6.28.orig/fs/lockd/clntproc.c > +++ linux-2.6.28/fs/lockd/clntproc.c > @@ -10,8 +10,8 @@ > #include <linux/types.h> > #include <linux/errno.h> > #include <linux/fs.h> > +#include <linux/mount.h> > #include <linux/nfs_fs.h> > -#include <linux/utsname.h> > #include <linux/freezer.h> > #include <linux/sunrpc/clnt.h> > #include <linux/sunrpc/svc.h> > @@ -118,6 +118,11 @@ static struct nlm_lockowner *nlm_find_lo > return res; > } > > +struct nfs_server *fl_nfs_server(struct file_lock *fl) > +{ > + return NFS_SB(fl->fl_file->f_path.mnt->mnt_sb); > +} > + > /* > * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls > */ > @@ -125,15 +130,18 @@ static void nlmclnt_setlockargs(struct n > { > struct nlm_args *argp = &req->a_args; > struct nlm_lock *lock = &argp->lock; > + char *nodename; > > nlmclnt_next_cookie(&argp->cookie); > argp->state = nsm_local_state; > memcpy(&lock->fh, NFS_FH(fl->fl_file->f_path.dentry->d_inode), > sizeof(struct nfs_fh)); > - lock->caller = utsname()->nodename; > + > + nodename = fl_nfs_server(fl)->nodename; > + lock->caller = nodename; > lock->oh.data = req->a_owner; > lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%...@%s", > (unsigned int)fl->fl_u.nfs_fl.owner->pid, > - utsname()->nodename); > + nodename); > lock->svid = fl->fl_u.nfs_fl.owner->pid; > lock->fl.fl_start = fl->fl_start; > lock->fl.fl_end = fl->fl_end; > @@ -272,6 +280,7 @@ nlmclnt_call(struct rpc_cred *cred, stru > /* If we have no RPC client yet, create one. */ > if ((clnt = nlm_bind_host(host)) == NULL) > return -ENOLCK; > + clnt->cl_nfs_server = fl_nfs_server(&argp->lock.fl); > msg.rpc_proc = &clnt->cl_procinfo[proc]; > > /* Perform the RPC call. If an error occurs, try again */ > @@ -344,6 +353,7 @@ static struct rpc_task *__nlm_async_call > clnt = nlm_bind_host(host); > if (clnt == NULL) > goto out_err; > + clnt->cl_nfs_server = fl_nfs_server(&req->a_args.lock.fl); This change takes care of fixing NFS client locking requests, but the NFS server also makes lockd callbacks to the client. You won't have an nfs_server handle on the NFS server side. Generally, you ought to pass just the nodename where needed, not a pointer to the nfs_server. > msg->rpc_proc = &clnt->cl_procinfo[proc]; > task_setup_data.rpc_client = clnt; > > Index: linux-2.6.28/include/linux/nfs_fs.h > =================================================================== > --- linux-2.6.28.orig/include/linux/nfs_fs.h > +++ linux-2.6.28/include/linux/nfs_fs.h > @@ -262,6 +262,8 @@ static inline __u64 NFS_FILEID(const str > return NFS_I(inode)->fileid; > } > > +struct nfs_server *fl_nfs_server(struct file_lock *fl); > + > static inline void set_nfs_fileid(struct inode *inode, __u64 fileid) > { > NFS_I(inode)->fileid = fileid; > > -- -- Chuck Lever chuck[dot]lever[at]oracle[dot]com _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
