From 896526174ce2b6a773e187ebe5a047b68230e2c4 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 14 Sep 2012 17:24:11 -0400 Subject: NFS: Introduce "migration" mount option Currently, the Linux client uses a unique nfs_client_id4.id string when identifying itself to distinct NFS servers. To support transparent state migration, the Linux client will have to use the same nfs_client_id4 string for all servers it communicates with (also known as the "uniform client string" approach). Otherwise NFS servers can not recognize that open and lock state need to be merged after a file system transition. Unfortunately, there are some NFSv4.0 servers currently in the field that do not tolerate the uniform client string approach. Thus, by default, our NFSv4.0 mounts will continue to use the current approach, and we introduce a mount option that switches them to use the uniform model. Client administrators must identify which servers can be mounted with this option. Eventually most NFSv4.0 servers will be able to handle the uniform approach, and we can change the default. The first mount of a server controls the behavior for all subsequent mounts for the lifetime of that set of mounts of that server. After the last mount of that server is gone, the client erases the data structure that tracks the lease. A subsequent lease may then honor a different "migration" setting. This patch adds only the infrastructure for parsing the new mount option. Support for uniform client strings is added in a subsequent patch. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/super.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'fs/nfs/super.c') diff --git a/fs/nfs/super.c b/fs/nfs/super.c index b8eda700584b..056138d45c11 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -88,6 +88,7 @@ enum { Opt_sharecache, Opt_nosharecache, Opt_resvport, Opt_noresvport, Opt_fscache, Opt_nofscache, + Opt_migration, Opt_nomigration, /* Mount options that take integer arguments */ Opt_port, @@ -147,6 +148,8 @@ static const match_table_t nfs_mount_option_tokens = { { Opt_noresvport, "noresvport" }, { Opt_fscache, "fsc" }, { Opt_nofscache, "nofsc" }, + { Opt_migration, "migration" }, + { Opt_nomigration, "nomigration" }, { Opt_port, "port=%s" }, { Opt_rsize, "rsize=%s" }, @@ -676,6 +679,9 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, if (nfss->options & NFS_OPTION_FSCACHE) seq_printf(m, ",fsc"); + if (nfss->options & NFS_OPTION_MIGRATION) + seq_printf(m, ",migration"); + if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) { if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) seq_printf(m, ",lookupcache=none"); @@ -1243,6 +1249,12 @@ static int nfs_parse_mount_options(char *raw, kfree(mnt->fscache_uniq); mnt->fscache_uniq = NULL; break; + case Opt_migration: + mnt->options |= NFS_OPTION_MIGRATION; + break; + case Opt_nomigration: + mnt->options &= NFS_OPTION_MIGRATION; + break; /* * options that take numeric values @@ -1535,6 +1547,10 @@ static int nfs_parse_mount_options(char *raw, if (mnt->minorversion && mnt->version != 4) goto out_minorversion_mismatch; + if (mnt->options & NFS_OPTION_MIGRATION && + mnt->version != 4 && mnt->minorversion != 0) + goto out_migration_misuse; + /* * verify that any proto=/mountproto= options match the address * familiies in the addr=/mountaddr= options. @@ -1572,6 +1588,10 @@ out_minorversion_mismatch: printk(KERN_INFO "NFS: mount option vers=%u does not support " "minorversion=%u\n", mnt->version, mnt->minorversion); return 0; +out_migration_misuse: + printk(KERN_INFO + "NFS: 'migration' not supported for this NFS version\n"); + return 0; out_nomem: printk(KERN_INFO "NFS: not enough memory to parse option\n"); return 0; -- cgit v1.2.3 From 6f2ea7f2a3ff3cd342bface43f8b4bf5e431cf36 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 14 Sep 2012 17:24:41 -0400 Subject: NFS: Add nfs4_unique_id boot parameter An optional boot parameter is introduced to allow client administrators to specify a string that the Linux NFS client can insert into its nfs_client_id4 id string, to make it both more globally unique, and to ensure that it doesn't change even if the client's nodename changes. If this boot parameter is not specified, the client's nodename is used, as before. Client installation procedures can create a unique string (typically, a UUID) which remains unchanged during the lifetime of that client instance. This works just like creating a UUID for the label of the system's root and boot volumes. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- Documentation/filesystems/nfs/nfs.txt | 44 ++++++++++++++++++++++++++++++++--- Documentation/kernel-parameters.txt | 5 ++++ fs/nfs/nfs4_fs.h | 3 +++ fs/nfs/nfs4proc.c | 6 ++++- fs/nfs/super.c | 5 ++++ 5 files changed, 59 insertions(+), 4 deletions(-) (limited to 'fs/nfs/super.c') diff --git a/Documentation/filesystems/nfs/nfs.txt b/Documentation/filesystems/nfs/nfs.txt index f50f26ce6cd0..f2571c8bef74 100644 --- a/Documentation/filesystems/nfs/nfs.txt +++ b/Documentation/filesystems/nfs/nfs.txt @@ -12,9 +12,47 @@ and work is in progress on adding support for minor version 1 of the NFSv4 protocol. The purpose of this document is to provide information on some of the -upcall interfaces that are used in order to provide the NFS client with -some of the information that it requires in order to fully comply with -the NFS spec. +special features of the NFS client that can be configured by system +administrators. + + +The nfs4_unique_id parameter +============================ + +NFSv4 requires clients to identify themselves to servers with a unique +string. File open and lock state shared between one client and one server +is associated with this identity. To support robust NFSv4 state recovery +and transparent state migration, this identity string must not change +across client reboots. + +Without any other intervention, the Linux client uses a string that contains +the local system's node name. System administrators, however, often do not +take care to ensure that node names are fully qualified and do not change +over the lifetime of a client system. Node names can have other +administrative requirements that require particular behavior that does not +work well as part of an nfs_client_id4 string. + +The nfs.nfs4_unique_id boot parameter specifies a unique string that can be +used instead of a system's node name when an NFS client identifies itself to +a server. Thus, if the system's node name is not unique, or it changes, its +nfs.nfs4_unique_id stays the same, preventing collision with other clients +or loss of state during NFS reboot recovery or transparent state migration. + +The nfs.nfs4_unique_id string is typically a UUID, though it can contain +anything that is believed to be unique across all NFS clients. An +nfs4_unique_id string should be chosen when a client system is installed, +just as a system's root file system gets a fresh UUID in its label at +install time. + +The string should remain fixed for the lifetime of the client. It can be +changed safely if care is taken that the client shuts down cleanly and all +outstanding NFSv4 state has expired, to prevent loss of NFSv4 state. + +This string can be stored in an NFS client's grub.conf, or it can be provided +via a net boot facility such as PXE. It may also be specified as an nfs.ko +module parameter. Specifying a uniquifier string is not support for NFS +clients running in containers. + The DNS resolver ================ diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ad7e2e5088c1..396a1e66e0ae 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1719,6 +1719,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. will be autodetected by the client, and it will fall back to using the idmapper. To turn off this behaviour, set the value to '0'. + nfs.nfs4_unique_id= + [NFS4] Specify an additional fixed unique ident- + ification string that NFSv4 clients can insert into + their nfs_client_id4 string. This is typically a + UUID that is generated at system install time. nfs.send_implementation_id = [NFSv4.1] Send client implementation identification diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 832503c7a00e..a525fdefccde 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -380,6 +380,9 @@ extern bool nfs4_disable_idmapping; extern unsigned short max_session_slots; extern unsigned short send_implementation_id; +#define NFS4_CLIENT_ID_UNIQ_LEN (64) +extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN]; + /* nfs4sysctl.c */ #ifdef CONFIG_SYSCTL int nfs4_register_sysctl(void); diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index b5834abfcbff..9aa97112426f 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4068,9 +4068,13 @@ static unsigned int nfs4_init_uniform_client_string(const struct nfs_client *clp, char *buf, size_t len) { + char *nodename = clp->cl_rpcclient->cl_nodename; + + if (nfs4_client_id_uniquifier[0] != '\0') + nodename = nfs4_client_id_uniquifier; return scnprintf(buf, len, "Linux NFSv%u.%u %s", clp->rpc_ops->version, clp->cl_minorversion, - clp->cl_rpcclient->cl_nodename); + nodename); } /** diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 056138d45c11..56f02a9bd6d3 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2662,6 +2662,7 @@ unsigned int nfs_idmap_cache_timeout = 600; bool nfs4_disable_idmapping = true; unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE; unsigned short send_implementation_id = 1; +char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = ""; EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport); EXPORT_SYMBOL_GPL(nfs_callback_tcpport); @@ -2669,6 +2670,7 @@ EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout); EXPORT_SYMBOL_GPL(nfs4_disable_idmapping); EXPORT_SYMBOL_GPL(max_session_slots); EXPORT_SYMBOL_GPL(send_implementation_id); +EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier); #define NFS_CALLBACK_MAXPORTNR (65535U) @@ -2694,6 +2696,8 @@ static struct kernel_param_ops param_ops_portnr = { module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644); module_param(nfs_idmap_cache_timeout, int, 0644); module_param(nfs4_disable_idmapping, bool, 0644); +module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier, + NFS4_CLIENT_ID_UNIQ_LEN, 0600); MODULE_PARM_DESC(nfs4_disable_idmapping, "Turn off NFSv4 idmapping when using 'sec=sys'"); module_param(max_session_slots, ushort, 0644); @@ -2702,6 +2706,7 @@ MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 " module_param(send_implementation_id, ushort, 0644); MODULE_PARM_DESC(send_implementation_id, "Send implementation ID with NFSv4.1 exchange_id"); +MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string"); MODULE_ALIAS("nfs4"); #endif /* CONFIG_NFS_V4 */ -- cgit v1.2.3 From 7297cb682acb506ada2e01fbc9b447b04d69936c Mon Sep 17 00:00:00 2001 From: Daniel Walter Date: Wed, 26 Sep 2012 21:51:46 +0200 Subject: nfs: replace strict_strto* with kstrto* [nfs] replace strict_str* with kstr* variants * replace string conversions with newer kstr* functions Signed-off-by: Daniel Walter Signed-off-by: Trond Myklebust --- fs/nfs/idmap.c | 4 ++-- fs/nfs/super.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/nfs/super.c') diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c index 9985a0aea5ff..27dde503a6b6 100644 --- a/fs/nfs/idmap.c +++ b/fs/nfs/idmap.c @@ -158,7 +158,7 @@ static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *re return 0; memcpy(buf, name, namelen); buf[namelen] = '\0'; - if (strict_strtoul(buf, 0, &val) != 0) + if (kstrtoul(buf, 0, &val) != 0) return 0; *res = val; return 1; @@ -364,7 +364,7 @@ static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *typ if (data_size <= 0) { ret = -EINVAL; } else { - ret = strict_strtol(id_str, 10, &id_long); + ret = kstrtol(id_str, 10, &id_long); *id = (__u32)id_long; } return ret; diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 56f02a9bd6d3..a719bc0640b4 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1112,7 +1112,7 @@ static int nfs_get_option_ul(substring_t args[], unsigned long *option) string = match_strdup(args); if (string == NULL) return -ENOMEM; - rc = strict_strtoul(string, 10, option); + rc = kstrtoul(string, 10, option); kfree(string); return rc; @@ -2681,7 +2681,7 @@ static int param_set_portnr(const char *val, const struct kernel_param *kp) if (!val) return -EINVAL; - ret = strict_strtoul(val, 0, &num); + ret = kstrtoul(val, 0, &num); if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR) return -EINVAL; *((unsigned int *)kp->arg) = num; -- cgit v1.2.3 From 3dd4f8ef7b26d5d4ada6e2f4b92d99b5e2255f72 Mon Sep 17 00:00:00 2001 From: Stanislav Kinsbursky Date: Tue, 2 Oct 2012 14:19:04 +0400 Subject: nfs: declare nfs_xdev_mount as static Sparse warning: fs/nfs/super.c:2517:15: warning: symbol 'nfs_xdev_mount' was not declared. Should it be static? Signed-off-by: Stanislav Kinsbursky Signed-off-by: Trond Myklebust --- fs/nfs/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs/super.c') diff --git a/fs/nfs/super.c b/fs/nfs/super.c index a719bc0640b4..b4079bbd30dd 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2514,7 +2514,7 @@ EXPORT_SYMBOL_GPL(nfs_kill_super); /* * Clone an NFS2/3/4 server record on xdev traversal (FSID-change) */ -struct dentry * +static struct dentry * nfs_xdev_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data) { -- cgit v1.2.3