From ab7017a3a0a64b953e091619c30413b3721d925d Mon Sep 17 00:00:00 2001 From: Bryan Schumaker Date: Mon, 30 Jul 2012 16:05:16 -0400 Subject: NFS: Add version registering framework This patch adds in the code to track multiple versions of the NFS protocol. I created default structures for v2, v3 and v4 so that each version can continue to work while I convert them into kernel modules. I also removed the const parameter from the rpc_version array so that I can change it at runtime. Signed-off-by: Bryan Schumaker Signed-off-by: Trond Myklebust --- fs/nfs/client.c | 147 ++++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 112 insertions(+), 35 deletions(-) (limited to 'fs/nfs/client.c') diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 65afa382c5e..462de24482b 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -51,25 +51,23 @@ #include "internal.h" #include "fscache.h" #include "pnfs.h" +#include "nfs.h" #include "netns.h" #define NFSDBG_FACILITY NFSDBG_CLIENT static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq); +static DEFINE_SPINLOCK(nfs_version_lock); +static DEFINE_MUTEX(nfs_version_mutex); +static LIST_HEAD(nfs_versions); /* * RPC cruft for NFS */ static const struct rpc_version *nfs_version[5] = { -#ifdef CONFIG_NFS_V2 - [2] = &nfs_version2, -#endif -#ifdef CONFIG_NFS_V3 - [3] = &nfs_version3, -#endif -#ifdef CONFIG_NFS_V4 - [4] = &nfs_version4, -#endif + [2] = NULL, + [3] = NULL, + [4] = NULL, }; const struct rpc_program nfs_program = { @@ -101,6 +99,93 @@ const struct rpc_program nfsacl_program = { }; #endif /* CONFIG_NFS_V3_ACL */ +static struct nfs_subversion *find_nfs_version(unsigned int version) +{ + struct nfs_subversion *nfs; + spin_lock(&nfs_version_lock); + + list_for_each_entry(nfs, &nfs_versions, list) { + if (nfs->rpc_ops->version == version) { + spin_unlock(&nfs_version_lock); + return nfs; + } + }; + + spin_unlock(&nfs_version_lock); + return ERR_PTR(-EPROTONOSUPPORT);; +} + +struct nfs_subversion *get_nfs_version(unsigned int version) +{ + struct nfs_subversion *nfs = find_nfs_version(version); + + if (IS_ERR(nfs)) { + mutex_lock(&nfs_version_mutex); + request_module("nfs%d", version); + nfs = find_nfs_version(version); + mutex_unlock(&nfs_version_mutex); + } + + if (!IS_ERR(nfs)) + try_module_get(nfs->owner); + return nfs; +} + +void put_nfs_version(struct nfs_subversion *nfs) +{ + module_put(nfs->owner); +} + +void register_nfs_version(struct nfs_subversion *nfs) +{ + spin_lock(&nfs_version_lock); + + list_add(&nfs->list, &nfs_versions); + nfs_version[nfs->rpc_ops->version] = nfs->rpc_vers; + + spin_unlock(&nfs_version_lock); +} +EXPORT_SYMBOL_GPL(register_nfs_version); + +void unregister_nfs_version(struct nfs_subversion *nfs) +{ + spin_lock(&nfs_version_lock); + + nfs_version[nfs->rpc_ops->version] = NULL; + list_del(&nfs->list); + + spin_unlock(&nfs_version_lock); +} +EXPORT_SYMBOL_GPL(unregister_nfs_version); + +/* + * Preload all configured NFS versions during module init. + * This function should be edited after each protocol is converted, + * and eventually removed. + */ +int __init nfs_register_versions(void) +{ + int err = init_nfs_v2(); + if (err) + return err; + + err = init_nfs_v3(); + if (err) + return err; + + return init_nfs_v4(); +} + +/* + * Remove each pre-loaded NFS version + */ +void nfs_unregister_versions(void) +{ + exit_nfs_v2(); + exit_nfs_v3(); + exit_nfs_v4(); +} + /* * Allocate a shared client record * @@ -116,7 +201,10 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init) if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL) goto error_0; - clp->rpc_ops = cl_init->rpc_ops; + clp->cl_nfs_mod = cl_init->nfs_mod; + try_module_get(clp->cl_nfs_mod->owner); + + clp->rpc_ops = clp->cl_nfs_mod->rpc_ops; atomic_set(&clp->cl_count, 1); clp->cl_cons_state = NFS_CS_INITING; @@ -145,6 +233,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init) return clp; error_cleanup: + put_nfs_version(clp->cl_nfs_mod); kfree(clp); error_0: return ERR_PTR(err); @@ -205,6 +294,7 @@ void nfs_free_client(struct nfs_client *clp) put_rpccred(clp->cl_machine_cred); put_net(clp->cl_net); + put_nfs_version(clp->cl_nfs_mod); kfree(clp->cl_hostname); kfree(clp); @@ -362,7 +452,7 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat continue; /* Different NFS versions cannot share the same nfs_client */ - if (clp->rpc_ops != data->rpc_ops) + if (clp->rpc_ops != data->nfs_mod->rpc_ops) continue; if (clp->cl_proto != data->proto) @@ -431,9 +521,10 @@ nfs_get_client(const struct nfs_client_initdata *cl_init, { struct nfs_client *clp, *new = NULL; struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id); + const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops; dprintk("--> nfs_get_client(%s,v%u)\n", - cl_init->hostname ?: "", cl_init->rpc_ops->version); + cl_init->hostname ?: "", rpc_ops->version); /* see if the client already exists */ do { @@ -450,14 +541,13 @@ nfs_get_client(const struct nfs_client_initdata *cl_init, list_add(&new->cl_share_link, &nn->nfs_client_list); spin_unlock(&nn->nfs_client_lock); new->cl_flags = cl_init->init_flags; - return cl_init->rpc_ops->init_client(new, - timeparms, ip_addr, - authflavour); + return rpc_ops->init_client(new, timeparms, ip_addr, + authflavour); } spin_unlock(&nn->nfs_client_lock); - new = cl_init->rpc_ops->alloc_client(cl_init); + new = rpc_ops->alloc_client(cl_init); } while (!IS_ERR(new)); dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n", @@ -714,13 +804,14 @@ error: * Create a version 2 or 3 client */ static int nfs_init_server(struct nfs_server *server, - const struct nfs_parsed_mount_data *data) + const struct nfs_parsed_mount_data *data, + struct nfs_subversion *nfs_mod) { struct nfs_client_initdata cl_init = { .hostname = data->nfs_server.hostname, .addr = (const struct sockaddr *)&data->nfs_server.address, .addrlen = data->nfs_server.addrlen, - .rpc_ops = NULL, + .nfs_mod = nfs_mod, .proto = data->nfs_server.protocol, .net = data->net, }; @@ -730,21 +821,6 @@ static int nfs_init_server(struct nfs_server *server, dprintk("--> nfs_init_server()\n"); - switch (data->version) { -#ifdef CONFIG_NFS_V2 - case 2: - cl_init.rpc_ops = &nfs_v2_clientops; - break; -#endif -#ifdef CONFIG_NFS_V3 - case 3: - cl_init.rpc_ops = &nfs_v3_clientops; - break; -#endif - default: - return -EPROTONOSUPPORT; - } - nfs_init_timeout_values(&timeparms, data->nfs_server.protocol, data->timeo, data->retrans); if (data->flags & NFS_MOUNT_NORESVPORT) @@ -1033,7 +1109,8 @@ void nfs_free_server(struct nfs_server *server) * - keyed on server and FSID */ struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data, - struct nfs_fh *mntfh) + struct nfs_fh *mntfh, + struct nfs_subversion *nfs_mod) { struct nfs_server *server; struct nfs_fattr *fattr; @@ -1049,7 +1126,7 @@ struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data, goto error; /* Get a client representation */ - error = nfs_init_server(server, data); + error = nfs_init_server(server, data, nfs_mod); if (error < 0) goto error; -- cgit v1.2.3