From 24c8dbbb5f777187d660393599641ab3307b4b97 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 22 Aug 2006 20:06:10 -0400 Subject: NFS: Generalise the nfs_client structure Generalise the nfs_client structure by: (1) Moving nfs_client to a more general place (nfs_fs_sb.h). (2) Renaming its maintenance routines to be non-NFS4 specific. (3) Move those maintenance routines to a new non-NFS4 specific file (client.c) and move the declarations to internal.h. (4) Make nfs_find/get_client() take a full sockaddr_in to include the port number (will be required for NFS2/3). (5) Make nfs_find/get_client() take the NFS protocol version (again will be required to differentiate NFS2, 3 & 4 client records). Also: (6) Make nfs_client construction proceed akin to inodes, marking them as under construction and providing a function to indicate completion. (7) Make nfs_get_client() wait interruptibly if it finds a client that it can share, but that client is currently being constructed. (8) Make nfs4_create_client() use (6) and (7) instead of locking cl_sem. Signed-Off-By: David Howells Signed-off-by: Trond Myklebust --- fs/nfs/client.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 312 insertions(+) create mode 100644 fs/nfs/client.c (limited to 'fs/nfs/client.c') diff --git a/fs/nfs/client.c b/fs/nfs/client.c new file mode 100644 index 00000000000..cb5e92463bd --- /dev/null +++ b/fs/nfs/client.c @@ -0,0 +1,312 @@ +/* client.c: NFS client sharing and management code + * + * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + + +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "nfs4_fs.h" +#include "callback.h" +#include "delegation.h" +#include "iostat.h" +#include "internal.h" + +#define NFSDBG_FACILITY NFSDBG_CLIENT + +static DEFINE_SPINLOCK(nfs_client_lock); +static LIST_HEAD(nfs_client_list); +static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq); + +/* + * Allocate a shared client record + * + * Since these are allocated/deallocated very rarely, we don't + * bother putting them in a slab cache... + */ +static struct nfs_client *nfs_alloc_client(const char *hostname, + const struct sockaddr_in *addr, + int nfsversion) +{ + struct nfs_client *clp; + int error; + + if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL) + goto error_0; + + error = rpciod_up(); + if (error < 0) { + dprintk("%s: couldn't start rpciod! Error = %d\n", + __FUNCTION__, error); + __set_bit(NFS_CS_RPCIOD, &clp->cl_res_state); + goto error_1; + } + + if (nfsversion == 4) { + if (nfs_callback_up() < 0) + goto error_2; + __set_bit(NFS_CS_CALLBACK, &clp->cl_res_state); + } + + atomic_set(&clp->cl_count, 1); + clp->cl_cons_state = NFS_CS_INITING; + + clp->cl_nfsversion = nfsversion; + memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr)); + + if (hostname) { + clp->cl_hostname = kstrdup(hostname, GFP_KERNEL); + if (!clp->cl_hostname) + goto error_3; + } + + INIT_LIST_HEAD(&clp->cl_superblocks); + clp->cl_rpcclient = ERR_PTR(-EINVAL); + +#ifdef CONFIG_NFS_V4 + init_rwsem(&clp->cl_sem); + INIT_LIST_HEAD(&clp->cl_delegations); + INIT_LIST_HEAD(&clp->cl_state_owners); + INIT_LIST_HEAD(&clp->cl_unused); + spin_lock_init(&clp->cl_lock); + INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp); + rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client"); + clp->cl_boot_time = CURRENT_TIME; + clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED; +#endif + + return clp; + +error_3: + nfs_callback_down(); + __clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state); +error_2: + rpciod_down(); + __clear_bit(NFS_CS_RPCIOD, &clp->cl_res_state); +error_1: + kfree(clp); +error_0: + return NULL; +} + +/* + * Destroy a shared client record + */ +static void nfs_free_client(struct nfs_client *clp) +{ + dprintk("--> nfs_free_client(%d)\n", clp->cl_nfsversion); + +#ifdef CONFIG_NFS_V4 + if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state)) { + while (!list_empty(&clp->cl_unused)) { + struct nfs4_state_owner *sp; + + sp = list_entry(clp->cl_unused.next, + struct nfs4_state_owner, + so_list); + list_del(&sp->so_list); + kfree(sp); + } + BUG_ON(!list_empty(&clp->cl_state_owners)); + nfs_idmap_delete(clp); + } +#endif + + /* -EIO all pending I/O */ + if (!IS_ERR(clp->cl_rpcclient)) + rpc_shutdown_client(clp->cl_rpcclient); + + if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state)) + nfs_callback_down(); + + if (__test_and_clear_bit(NFS_CS_RPCIOD, &clp->cl_res_state)) + rpciod_down(); + + kfree(clp->cl_hostname); + kfree(clp); + + dprintk("<-- nfs_free_client()\n"); +} + +/* + * Release a reference to a shared client record + */ +void nfs_put_client(struct nfs_client *clp) +{ + dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count)); + + if (atomic_dec_and_lock(&clp->cl_count, &nfs_client_lock)) { + list_del(&clp->cl_share_link); + spin_unlock(&nfs_client_lock); + + BUG_ON(!list_empty(&clp->cl_superblocks)); + + nfs_free_client(clp); + } +} + +/* + * Find a client by address + * - caller must hold nfs_client_lock + */ +static struct nfs_client *__nfs_find_client(const struct sockaddr_in *addr, int nfsversion) +{ + struct nfs_client *clp; + + list_for_each_entry(clp, &nfs_client_list, cl_share_link) { + /* Different NFS versions cannot share the same nfs_client */ + if (clp->cl_nfsversion != nfsversion) + continue; + + if (memcmp(&clp->cl_addr.sin_addr, &addr->sin_addr, + sizeof(clp->cl_addr.sin_addr)) != 0) + continue; + + if (clp->cl_addr.sin_port == addr->sin_port) + goto found; + } + + return NULL; + +found: + atomic_inc(&clp->cl_count); + return clp; +} + +/* + * Find a client by IP address and protocol version + * - returns NULL if no such client + */ +struct nfs_client *nfs_find_client(const struct sockaddr_in *addr, int nfsversion) +{ + struct nfs_client *clp; + + spin_lock(&nfs_client_lock); + clp = __nfs_find_client(addr, nfsversion); + spin_unlock(&nfs_client_lock); + + BUG_ON(clp->cl_cons_state == 0); + + return clp; +} + +/* + * Look up a client by IP address and protocol version + * - creates a new record if one doesn't yet exist + */ +struct nfs_client *nfs_get_client(const char *hostname, + const struct sockaddr_in *addr, + int nfsversion) +{ + struct nfs_client *clp, *new = NULL; + int error; + + dprintk("--> nfs_get_client(%s,"NIPQUAD_FMT":%d,%d)\n", + hostname ?: "", NIPQUAD(addr->sin_addr), + addr->sin_port, nfsversion); + + /* see if the client already exists */ + do { + spin_lock(&nfs_client_lock); + + clp = __nfs_find_client(addr, nfsversion); + if (clp) + goto found_client; + if (new) + goto install_client; + + spin_unlock(&nfs_client_lock); + + new = nfs_alloc_client(hostname, addr, nfsversion); + } while (new); + + return ERR_PTR(-ENOMEM); + + /* install a new client and return with it unready */ +install_client: + clp = new; + list_add(&clp->cl_share_link, &nfs_client_list); + spin_unlock(&nfs_client_lock); + dprintk("--> nfs_get_client() = %p [new]\n", clp); + return clp; + + /* found an existing client + * - make sure it's ready before returning + */ +found_client: + spin_unlock(&nfs_client_lock); + + if (new) + nfs_free_client(new); + + if (clp->cl_cons_state == NFS_CS_INITING) { + DECLARE_WAITQUEUE(myself, current); + + add_wait_queue(&nfs_client_active_wq, &myself); + + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + if (signal_pending(current) || + clp->cl_cons_state > NFS_CS_READY) + break; + schedule(); + } + + remove_wait_queue(&nfs_client_active_wq, &myself); + + if (signal_pending(current)) { + nfs_put_client(clp); + return ERR_PTR(-ERESTARTSYS); + } + } + + if (clp->cl_cons_state < NFS_CS_READY) { + error = clp->cl_cons_state; + nfs_put_client(clp); + return ERR_PTR(error); + } + + dprintk("--> nfs_get_client() = %p [share]\n", clp); + return clp; +} + +/* + * Mark a server as ready or failed + */ +void nfs_mark_client_ready(struct nfs_client *clp, int state) +{ + clp->cl_cons_state = state; + wake_up_all(&nfs_client_active_wq); +} -- cgit v1.2.3