diff options
| -rw-r--r-- | fs/nfsd/nfs4recover.c | 444 |
1 files changed, 443 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index e616f88b7f19..cec62ed2a064 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -1,5 +1,6 @@ /* * Copyright (c) 2004 The Regents of the University of Michigan. +* Copyright (c) 2012 Jeff Layton <jlayton@redhat.com> * All rights reserved. * * Andy Adamson <andros@citi.umich.edu> @@ -36,10 +37,16 @@ #include <linux/namei.h> #include <linux/crypto.h> #include <linux/sched.h> +#include <linux/fs.h> +#include <net/net_namespace.h> +#include <linux/sunrpc/rpc_pipe_fs.h> +#include <linux/sunrpc/clnt.h> +#include <linux/nfsd/cld.h> #include "nfsd.h" #include "state.h" #include "vfs.h" +#include "netns.h" #define NFSDDBG_FACILITY NFSDDBG_PROC @@ -486,12 +493,447 @@ static struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = { .grace_done = nfsd4_recdir_purge_old, }; +/* Globals */ +#define NFSD_PIPE_DIR "nfsd" +#define NFSD_CLD_PIPE "cld" + +/* per-net-ns structure for holding cld upcall info */ +struct cld_net { + struct rpc_pipe *cn_pipe; + spinlock_t cn_lock; + struct list_head cn_list; + unsigned int cn_xid; +}; + +struct cld_upcall { + struct list_head cu_list; + struct cld_net *cu_net; + struct task_struct *cu_task; + struct cld_msg cu_msg; +}; + +static int +__cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg) +{ + int ret; + struct rpc_pipe_msg msg; + + memset(&msg, 0, sizeof(msg)); + msg.data = cmsg; + msg.len = sizeof(*cmsg); + + /* + * Set task state before we queue the upcall. That prevents + * wake_up_process in the downcall from racing with schedule. + */ + set_current_state(TASK_UNINTERRUPTIBLE); + ret = rpc_queue_upcall(pipe, &msg); + if (ret < 0) { + set_current_state(TASK_RUNNING); + goto out; + } + + schedule(); + set_current_state(TASK_RUNNING); + + if (msg.errno < 0) + ret = msg.errno; +out: + return ret; +} + +static int +cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg) +{ + int ret; + + /* + * -EAGAIN occurs when pipe is closed and reopened while there are + * upcalls queued. + */ + do { + ret = __cld_pipe_upcall(pipe, cmsg); + } while (ret == -EAGAIN); + + return ret; +} + +static ssize_t +cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) +{ + struct cld_upcall *tmp, *cup; + struct cld_msg *cmsg = (struct cld_msg *)src; + uint32_t xid; + struct nfsd_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info, + nfsd_net_id); + struct cld_net *cn = nn->cld_net; + + if (mlen != sizeof(*cmsg)) { + dprintk("%s: got %lu bytes, expected %lu\n", __func__, mlen, + sizeof(*cmsg)); + return -EINVAL; + } + + /* copy just the xid so we can try to find that */ + if (copy_from_user(&xid, &cmsg->cm_xid, sizeof(xid)) != 0) { + dprintk("%s: error when copying xid from userspace", __func__); + return -EFAULT; + } + + /* walk the list and find corresponding xid */ + cup = NULL; + spin_lock(&cn->cn_lock); + list_for_each_entry(tmp, &cn->cn_list, cu_list) { + if (get_unaligned(&tmp->cu_msg.cm_xid) == xid) { + cup = tmp; + list_del_init(&cup->cu_list); + break; + } + } + spin_unlock(&cn->cn_lock); + + /* couldn't find upcall? */ + if (!cup) { + dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, + cup->cu_msg.cm_xid); + return -EINVAL; + } + + if (copy_from_user(&cup->cu_msg, src, mlen) != 0) + return -EFAULT; + + wake_up_process(cup->cu_task); + return mlen; +} + +static void +cld_pipe_destroy_msg(struct rpc_pipe_msg *msg) +{ + struct cld_msg *cmsg = msg->data; + struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, + cu_msg); + + /* errno >= 0 means we got a downcall */ + if (msg->errno >= 0) + return; + + wake_up_process(cup->cu_task); +} + +static const struct rpc_pipe_ops cld_upcall_ops = { + .upcall = rpc_pipe_generic_upcall, + .downcall = cld_pipe_downcall, + .destroy_msg = cld_pipe_destroy_msg, +}; + +static struct dentry * +nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe) +{ + struct dentry *dir, *dentry; + + dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR); + if (dir == NULL) + return ERR_PTR(-ENOENT); + dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe); + dput(dir); + return dentry; +} + +static void +nfsd4_cld_unregister_sb(struct rpc_pipe *pipe) +{ + if (pipe->dentry) + rpc_unlink(pipe->dentry); +} + +static struct dentry * +nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe) +{ + struct super_block *sb; + struct dentry *dentry; + + sb = rpc_get_sb_net(net); + if (!sb) + return NULL; + dentry = nfsd4_cld_register_sb(sb, pipe); + rpc_put_sb_net(net); + return dentry; +} + +static void +nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe) +{ + struct super_block *sb; + + sb = rpc_get_sb_net(net); + if (sb) { + nfsd4_cld_unregister_sb(pipe); + rpc_put_sb_net(net); + } +} + +/* Initialize rpc_pipefs pipe for communication with client tracking daemon */ +static int +nfsd4_init_cld_pipe(struct net *net) +{ + int ret; + struct dentry *dentry; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct cld_net *cn; + + if (nn->cld_net) + return 0; + + cn = kzalloc(sizeof(*cn), GFP_KERNEL); + if (!cn) { + ret = -ENOMEM; + goto err; + } + + cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN); + if (IS_ERR(cn->cn_pipe)) { + ret = PTR_ERR(cn->cn_pipe); + goto err; + } + spin_lock_init(&cn->cn_lock); + INIT_LIST_HEAD(&cn->cn_list); + + dentry = nfsd4_cld_register_net(net, cn->cn_pipe); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err_destroy_data; + } + + cn->cn_pipe->dentry = dentry; + nn->cld_net = cn; + return 0; + +err_destroy_data: + rpc_destroy_pipe_data(cn->cn_pipe); +err: + kfree(cn); + printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n", + ret); + return ret; +} + +static void +nfsd4_remove_cld_pipe(struct net *net) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct cld_net *cn = nn->cld_net; + + nfsd4_cld_unregister_net(net, cn->cn_pipe); + rpc_destroy_pipe_data(cn->cn_pipe); + kfree(nn->cld_net); + nn->cld_net = NULL; +} + +static struct cld_upcall * +alloc_cld_upcall(struct cld_net *cn) +{ + struct cld_upcall *new, *tmp; + + new = kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return new; + + /* FIXME: hard cap on number in flight? */ +restart_search: + spin_lock(&cn->cn_lock); + list_for_each_entry(tmp, &cn->cn_list, cu_list) { + if (tmp->cu_msg.cm_xid == cn->cn_xid) { + cn->cn_xid++; + spin_unlock(&cn->cn_lock); + goto restart_search; + } + } + new->cu_task = current; + new->cu_msg.cm_vers = CLD_UPCALL_VERSION; + put_unaligned(cn->cn_xid++, &new->cu_msg.cm_xid); + new->cu_net = cn; + list_add(&new->cu_list, &cn->cn_list); + spin_unlock(&cn->cn_lock); + + dprintk("%s: allocated xid %u\n", __func__, new->cu_msg.cm_xid); + + return new; +} + +static void +free_cld_upcall(struct cld_upcall *victim) +{ + struct cld_net *cn = victim->cu_net; + + spin_lock(&cn->cn_lock); + list_del(&victim->cu_list); + spin_unlock(&cn->cn_lock); + kfree(victim); +} + +/* Ask daemon to create a new record */ +static void +nfsd4_cld_create(struct nfs4_client *clp) +{ + int ret; + struct cld_upcall *cup; + /* FIXME: determine net from clp */ + struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id); + struct cld_net *cn = nn->cld_net; + + /* Don't upcall if it's already stored */ + if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) + return; + + cup = alloc_cld_upcall(cn); + if (!cup) { + ret = -ENOMEM; + goto out_err; + } + + cup->cu_msg.cm_cmd = Cld_Create; + cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len; + memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data, + clp->cl_name.len); + + ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg); + if (!ret) { + ret = cup->cu_msg.cm_status; + set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags); + } + + free_cld_upcall(cup); +out_err: + if (ret) + printk(KERN_ERR "NFSD: Unable to create client " + "record on stable storage: %d\n", ret); +} + +/* Ask daemon to create a new record */ +static void +nfsd4_cld_remove(struct nfs4_client *clp) +{ + int ret; + struct cld_upcall *cup; + /* FIXME: determine net from clp */ + struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id); + struct cld_net *cn = nn->cld_net; + + /* Don't upcall if it's already removed */ + if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) + return; + + cup = alloc_cld_upcall(cn); + if (!cup) { + ret = -ENOMEM; + goto out_err; + } + + cup->cu_msg.cm_cmd = Cld_Remove; + cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len; + memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data, + clp->cl_name.len); + + ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg); + if (!ret) { + ret = cup->cu_msg.cm_status; + clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags); + } + + free_cld_upcall(cup); +out_err: + if (ret) + printk(KERN_ERR "NFSD: Unable to remove client " + "record from stable storage: %d\n", ret); +} + +/* Check for presence of a record, and update its timestamp */ +static int +nfsd4_cld_check(struct nfs4_client *clp) +{ + int ret; + struct cld_upcall *cup; + /* FIXME: determine net from clp */ + struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id); + struct cld_net *cn = nn->cld_net; + + /* Don't upcall if one was already stored during this grace pd */ + if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) + return 0; + + cup = alloc_cld_upcall(cn); + if (!cup) { + printk(KERN_ERR "NFSD: Unable to check client record on " + "stable storage: %d\n", -ENOMEM); + return -ENOMEM; + } + + cup->cu_msg.cm_cmd = Cld_Check; + cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len; + memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data, + clp->cl_name.len); + + ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg); + if (!ret) { + ret = cup->cu_msg.cm_status; + set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags); + } + + free_cld_upcall(cup); + return ret; +} + +static void +nfsd4_cld_grace_done(struct net *net, time_t boot_time) +{ + int ret; + struct cld_upcall *cup; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct cld_net *cn = nn->cld_net; + + cup = alloc_cld_upcall(cn); + if (!cup) { + ret = -ENOMEM; + goto out_err; + } + + cup->cu_msg.cm_cmd = Cld_GraceDone; + cup->cu_msg.cm_u.cm_gracetime = (int64_t)boot_time; + ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg); + if (!ret) + ret = cup->cu_msg.cm_status; + + free_cld_upcall(cup); +out_err: + if (ret) + printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret); +} + +static struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = { + .init = nfsd4_init_cld_pipe, + .exit = nfsd4_remove_cld_pipe, + .create = nfsd4_cld_create, + .remove = nfsd4_cld_remove, + .check = nfsd4_cld_check, + .grace_done = nfsd4_cld_grace_done, +}; + int nfsd4_client_tracking_init(struct net *net) { int status; + struct path path; - client_tracking_ops = &nfsd4_legacy_tracking_ops; + if (!client_tracking_ops) { + client_tracking_ops = &nfsd4_cld_tracking_ops; + status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path); + if (!status) { + if (S_ISDIR(path.dentry->d_inode->i_mode)) + client_tracking_ops = + &nfsd4_legacy_tracking_ops; + path_put(&path); + } + } status = client_tracking_ops->init(net); if (status) { |