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. 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. Thoughts? Signed-off-by: Matt Helsley <matthltc@xxxxxxxxxx> Cc: Cedric Le Goater <clg@xxxxxxxxxx> Cc: Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx> Cc: linux-nfs@xxxxxxxxxxxxxxx Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxx> Cc: Chuck Lever <chuck.lever@xxxxxxxxxx> Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> Cc: Linux Containers <containers@xxxxxxxxxxxxxx> --- 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; 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), "%u@%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); 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; -- -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
