From 392e8802486cb573b916e746010e141a75f507e6 Mon Sep 17 00:00:00 2001 From: Kevin Date: Sat, 15 Nov 2014 09:58:27 +0800 Subject: init android origin source code --- ANDROID_3.4.5/fs/nfs/super.c | 3149 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 3149 insertions(+) create mode 100644 ANDROID_3.4.5/fs/nfs/super.c (limited to 'ANDROID_3.4.5/fs/nfs/super.c') diff --git a/ANDROID_3.4.5/fs/nfs/super.c b/ANDROID_3.4.5/fs/nfs/super.c new file mode 100644 index 00000000..4ac7fca7 --- /dev/null +++ b/ANDROID_3.4.5/fs/nfs/super.c @@ -0,0 +1,3149 @@ +/* + * linux/fs/nfs/super.c + * + * Copyright (C) 1992 Rick Sladkey + * + * nfs superblock handling functions + * + * Modularised by Alan Cox , while hacking some + * experimental NFS changes. Modularisation taken straight from SYS5 fs. + * + * Change to nfs_read_super() to permit NFS mounts to multi-homed hosts. + * J.S.Peatfield@damtp.cam.ac.uk + * + * Split from inode.c by David Howells + * + * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a + * particular server are held in the same superblock + * - NFS superblocks can have several effective roots to the dentry tree + * - directory type roots are spliced into the tree when a path from one root reaches the root + * of another (see nfs_lookup()) + */ + +#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 +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "nfs4_fs.h" +#include "callback.h" +#include "delegation.h" +#include "iostat.h" +#include "internal.h" +#include "fscache.h" +#include "pnfs.h" + +#define NFSDBG_FACILITY NFSDBG_VFS + +#ifdef CONFIG_NFS_V3 +#define NFS_DEFAULT_VERSION 3 +#else +#define NFS_DEFAULT_VERSION 2 +#endif + +enum { + /* Mount options that take no arguments */ + Opt_soft, Opt_hard, + Opt_posix, Opt_noposix, + Opt_cto, Opt_nocto, + Opt_ac, Opt_noac, + Opt_lock, Opt_nolock, + Opt_udp, Opt_tcp, Opt_rdma, + Opt_acl, Opt_noacl, + Opt_rdirplus, Opt_nordirplus, + Opt_sharecache, Opt_nosharecache, + Opt_resvport, Opt_noresvport, + Opt_fscache, Opt_nofscache, + + /* Mount options that take integer arguments */ + Opt_port, + Opt_rsize, Opt_wsize, Opt_bsize, + Opt_timeo, Opt_retrans, + Opt_acregmin, Opt_acregmax, + Opt_acdirmin, Opt_acdirmax, + Opt_actimeo, + Opt_namelen, + Opt_mountport, + Opt_mountvers, + Opt_minorversion, + + /* Mount options that take string arguments */ + Opt_nfsvers, + Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost, + Opt_addr, Opt_mountaddr, Opt_clientaddr, + Opt_lookupcache, + Opt_fscache_uniq, + Opt_local_lock, + + /* Special mount options */ + Opt_userspace, Opt_deprecated, Opt_sloppy, + + Opt_err +}; + +static const match_table_t nfs_mount_option_tokens = { + { Opt_userspace, "bg" }, + { Opt_userspace, "fg" }, + { Opt_userspace, "retry=%s" }, + + { Opt_sloppy, "sloppy" }, + + { Opt_soft, "soft" }, + { Opt_hard, "hard" }, + { Opt_deprecated, "intr" }, + { Opt_deprecated, "nointr" }, + { Opt_posix, "posix" }, + { Opt_noposix, "noposix" }, + { Opt_cto, "cto" }, + { Opt_nocto, "nocto" }, + { Opt_ac, "ac" }, + { Opt_noac, "noac" }, + { Opt_lock, "lock" }, + { Opt_nolock, "nolock" }, + { Opt_udp, "udp" }, + { Opt_tcp, "tcp" }, + { Opt_rdma, "rdma" }, + { Opt_acl, "acl" }, + { Opt_noacl, "noacl" }, + { Opt_rdirplus, "rdirplus" }, + { Opt_nordirplus, "nordirplus" }, + { Opt_sharecache, "sharecache" }, + { Opt_nosharecache, "nosharecache" }, + { Opt_resvport, "resvport" }, + { Opt_noresvport, "noresvport" }, + { Opt_fscache, "fsc" }, + { Opt_nofscache, "nofsc" }, + + { Opt_port, "port=%s" }, + { Opt_rsize, "rsize=%s" }, + { Opt_wsize, "wsize=%s" }, + { Opt_bsize, "bsize=%s" }, + { Opt_timeo, "timeo=%s" }, + { Opt_retrans, "retrans=%s" }, + { Opt_acregmin, "acregmin=%s" }, + { Opt_acregmax, "acregmax=%s" }, + { Opt_acdirmin, "acdirmin=%s" }, + { Opt_acdirmax, "acdirmax=%s" }, + { Opt_actimeo, "actimeo=%s" }, + { Opt_namelen, "namlen=%s" }, + { Opt_mountport, "mountport=%s" }, + { Opt_mountvers, "mountvers=%s" }, + { Opt_minorversion, "minorversion=%s" }, + + { Opt_nfsvers, "nfsvers=%s" }, + { Opt_nfsvers, "vers=%s" }, + + { Opt_sec, "sec=%s" }, + { Opt_proto, "proto=%s" }, + { Opt_mountproto, "mountproto=%s" }, + { Opt_addr, "addr=%s" }, + { Opt_clientaddr, "clientaddr=%s" }, + { Opt_mounthost, "mounthost=%s" }, + { Opt_mountaddr, "mountaddr=%s" }, + + { Opt_lookupcache, "lookupcache=%s" }, + { Opt_fscache_uniq, "fsc=%s" }, + { Opt_local_lock, "local_lock=%s" }, + + /* The following needs to be listed after all other options */ + { Opt_nfsvers, "v%s" }, + + { Opt_err, NULL } +}; + +enum { + Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma, + + Opt_xprt_err +}; + +static const match_table_t nfs_xprt_protocol_tokens = { + { Opt_xprt_udp, "udp" }, + { Opt_xprt_udp6, "udp6" }, + { Opt_xprt_tcp, "tcp" }, + { Opt_xprt_tcp6, "tcp6" }, + { Opt_xprt_rdma, "rdma" }, + + { Opt_xprt_err, NULL } +}; + +enum { + Opt_sec_none, Opt_sec_sys, + Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p, + Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp, + Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp, + + Opt_sec_err +}; + +static const match_table_t nfs_secflavor_tokens = { + { Opt_sec_none, "none" }, + { Opt_sec_none, "null" }, + { Opt_sec_sys, "sys" }, + + { Opt_sec_krb5, "krb5" }, + { Opt_sec_krb5i, "krb5i" }, + { Opt_sec_krb5p, "krb5p" }, + + { Opt_sec_lkey, "lkey" }, + { Opt_sec_lkeyi, "lkeyi" }, + { Opt_sec_lkeyp, "lkeyp" }, + + { Opt_sec_spkm, "spkm3" }, + { Opt_sec_spkmi, "spkm3i" }, + { Opt_sec_spkmp, "spkm3p" }, + + { Opt_sec_err, NULL } +}; + +enum { + Opt_lookupcache_all, Opt_lookupcache_positive, + Opt_lookupcache_none, + + Opt_lookupcache_err +}; + +static match_table_t nfs_lookupcache_tokens = { + { Opt_lookupcache_all, "all" }, + { Opt_lookupcache_positive, "pos" }, + { Opt_lookupcache_positive, "positive" }, + { Opt_lookupcache_none, "none" }, + + { Opt_lookupcache_err, NULL } +}; + +enum { + Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix, + Opt_local_lock_none, + + Opt_local_lock_err +}; + +static match_table_t nfs_local_lock_tokens = { + { Opt_local_lock_all, "all" }, + { Opt_local_lock_flock, "flock" }, + { Opt_local_lock_posix, "posix" }, + { Opt_local_lock_none, "none" }, + + { Opt_local_lock_err, NULL } +}; + +enum { + Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0, + Opt_vers_4_1, + + Opt_vers_err +}; + +static match_table_t nfs_vers_tokens = { + { Opt_vers_2, "2" }, + { Opt_vers_3, "3" }, + { Opt_vers_4, "4" }, + { Opt_vers_4_0, "4.0" }, + { Opt_vers_4_1, "4.1" }, + + { Opt_vers_err, NULL } +}; + +static void nfs_umount_begin(struct super_block *); +static int nfs_statfs(struct dentry *, struct kstatfs *); +static int nfs_show_options(struct seq_file *, struct dentry *); +static int nfs_show_devname(struct seq_file *, struct dentry *); +static int nfs_show_path(struct seq_file *, struct dentry *); +static int nfs_show_stats(struct seq_file *, struct dentry *); +static struct dentry *nfs_fs_mount(struct file_system_type *, + int, const char *, void *); +static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); +static void nfs_put_super(struct super_block *); +static void nfs_kill_super(struct super_block *); +static int nfs_remount(struct super_block *sb, int *flags, char *raw_data); + +static struct file_system_type nfs_fs_type = { + .owner = THIS_MODULE, + .name = "nfs", + .mount = nfs_fs_mount, + .kill_sb = nfs_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +struct file_system_type nfs_xdev_fs_type = { + .owner = THIS_MODULE, + .name = "nfs", + .mount = nfs_xdev_mount, + .kill_sb = nfs_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +static const struct super_operations nfs_sops = { + .alloc_inode = nfs_alloc_inode, + .destroy_inode = nfs_destroy_inode, + .write_inode = nfs_write_inode, + .put_super = nfs_put_super, + .statfs = nfs_statfs, + .evict_inode = nfs_evict_inode, + .umount_begin = nfs_umount_begin, + .show_options = nfs_show_options, + .show_devname = nfs_show_devname, + .show_path = nfs_show_path, + .show_stats = nfs_show_stats, + .remount_fs = nfs_remount, +}; + +#ifdef CONFIG_NFS_V4 +static int nfs4_validate_text_mount_data(void *options, + struct nfs_parsed_mount_data *args, const char *dev_name); +static struct dentry *nfs4_try_mount(int flags, const char *dev_name, + struct nfs_parsed_mount_data *data); +static struct dentry *nfs4_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); +static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); +static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); +static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); +static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data); +static void nfs4_kill_super(struct super_block *sb); + +static struct file_system_type nfs4_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .mount = nfs4_mount, + .kill_sb = nfs4_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +static struct file_system_type nfs4_remote_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .mount = nfs4_remote_mount, + .kill_sb = nfs4_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +struct file_system_type nfs4_xdev_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .mount = nfs4_xdev_mount, + .kill_sb = nfs4_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +static struct file_system_type nfs4_remote_referral_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .mount = nfs4_remote_referral_mount, + .kill_sb = nfs4_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +struct file_system_type nfs4_referral_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .mount = nfs4_referral_mount, + .kill_sb = nfs4_kill_super, + .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +static const struct super_operations nfs4_sops = { + .alloc_inode = nfs_alloc_inode, + .destroy_inode = nfs_destroy_inode, + .write_inode = nfs_write_inode, + .put_super = nfs_put_super, + .statfs = nfs_statfs, + .evict_inode = nfs4_evict_inode, + .umount_begin = nfs_umount_begin, + .show_options = nfs_show_options, + .show_devname = nfs_show_devname, + .show_path = nfs_show_path, + .show_stats = nfs_show_stats, + .remount_fs = nfs_remount, +}; +#endif + +static struct shrinker acl_shrinker = { + .shrink = nfs_access_cache_shrinker, + .seeks = DEFAULT_SEEKS, +}; + +/* + * Register the NFS filesystems + */ +int __init register_nfs_fs(void) +{ + int ret; + + ret = register_filesystem(&nfs_fs_type); + if (ret < 0) + goto error_0; + + ret = nfs_register_sysctl(); + if (ret < 0) + goto error_1; +#ifdef CONFIG_NFS_V4 + ret = register_filesystem(&nfs4_fs_type); + if (ret < 0) + goto error_2; +#endif + register_shrinker(&acl_shrinker); + return 0; + +#ifdef CONFIG_NFS_V4 +error_2: + nfs_unregister_sysctl(); +#endif +error_1: + unregister_filesystem(&nfs_fs_type); +error_0: + return ret; +} + +/* + * Unregister the NFS filesystems + */ +void __exit unregister_nfs_fs(void) +{ + unregister_shrinker(&acl_shrinker); +#ifdef CONFIG_NFS_V4 + unregister_filesystem(&nfs4_fs_type); +#endif + nfs_unregister_sysctl(); + unregister_filesystem(&nfs_fs_type); +} + +void nfs_sb_active(struct super_block *sb) +{ + struct nfs_server *server = NFS_SB(sb); + + if (atomic_inc_return(&server->active) == 1) + atomic_inc(&sb->s_active); +} + +void nfs_sb_deactive(struct super_block *sb) +{ + struct nfs_server *server = NFS_SB(sb); + + if (atomic_dec_and_test(&server->active)) + deactivate_super(sb); +} + +/* + * Deliver file system statistics to userspace + */ +static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct nfs_server *server = NFS_SB(dentry->d_sb); + unsigned char blockbits; + unsigned long blockres; + struct nfs_fh *fh = NFS_FH(dentry->d_inode); + struct nfs_fsstat res; + int error = -ENOMEM; + + res.fattr = nfs_alloc_fattr(); + if (res.fattr == NULL) + goto out_err; + + error = server->nfs_client->rpc_ops->statfs(server, fh, &res); + if (unlikely(error == -ESTALE)) { + struct dentry *pd_dentry; + + pd_dentry = dget_parent(dentry); + if (pd_dentry != NULL) { + nfs_zap_caches(pd_dentry->d_inode); + dput(pd_dentry); + } + } + nfs_free_fattr(res.fattr); + if (error < 0) + goto out_err; + + buf->f_type = NFS_SUPER_MAGIC; + + /* + * Current versions of glibc do not correctly handle the + * case where f_frsize != f_bsize. Eventually we want to + * report the value of wtmult in this field. + */ + buf->f_frsize = dentry->d_sb->s_blocksize; + + /* + * On most *nix systems, f_blocks, f_bfree, and f_bavail + * are reported in units of f_frsize. Linux hasn't had + * an f_frsize field in its statfs struct until recently, + * thus historically Linux's sys_statfs reports these + * fields in units of f_bsize. + */ + buf->f_bsize = dentry->d_sb->s_blocksize; + blockbits = dentry->d_sb->s_blocksize_bits; + blockres = (1 << blockbits) - 1; + buf->f_blocks = (res.tbytes + blockres) >> blockbits; + buf->f_bfree = (res.fbytes + blockres) >> blockbits; + buf->f_bavail = (res.abytes + blockres) >> blockbits; + + buf->f_files = res.tfiles; + buf->f_ffree = res.afiles; + + buf->f_namelen = server->namelen; + + return 0; + + out_err: + dprintk("%s: statfs error = %d\n", __func__, -error); + return error; +} + +/* + * Map the security flavour number to a name + */ +static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour) +{ + static const struct { + rpc_authflavor_t flavour; + const char *str; + } sec_flavours[] = { + { RPC_AUTH_NULL, "null" }, + { RPC_AUTH_UNIX, "sys" }, + { RPC_AUTH_GSS_KRB5, "krb5" }, + { RPC_AUTH_GSS_KRB5I, "krb5i" }, + { RPC_AUTH_GSS_KRB5P, "krb5p" }, + { RPC_AUTH_GSS_LKEY, "lkey" }, + { RPC_AUTH_GSS_LKEYI, "lkeyi" }, + { RPC_AUTH_GSS_LKEYP, "lkeyp" }, + { RPC_AUTH_GSS_SPKM, "spkm" }, + { RPC_AUTH_GSS_SPKMI, "spkmi" }, + { RPC_AUTH_GSS_SPKMP, "spkmp" }, + { UINT_MAX, "unknown" } + }; + int i; + + for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) { + if (sec_flavours[i].flavour == flavour) + break; + } + return sec_flavours[i].str; +} + +static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss, + int showdefaults) +{ + struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address; + + seq_printf(m, ",mountproto="); + switch (sap->sa_family) { + case AF_INET: + switch (nfss->mountd_protocol) { + case IPPROTO_UDP: + seq_printf(m, RPCBIND_NETID_UDP); + break; + case IPPROTO_TCP: + seq_printf(m, RPCBIND_NETID_TCP); + break; + default: + if (showdefaults) + seq_printf(m, "auto"); + } + break; + case AF_INET6: + switch (nfss->mountd_protocol) { + case IPPROTO_UDP: + seq_printf(m, RPCBIND_NETID_UDP6); + break; + case IPPROTO_TCP: + seq_printf(m, RPCBIND_NETID_TCP6); + break; + default: + if (showdefaults) + seq_printf(m, "auto"); + } + break; + default: + if (showdefaults) + seq_printf(m, "auto"); + } +} + +static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss, + int showdefaults) +{ + struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address; + + if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE) + return; + + switch (sap->sa_family) { + case AF_INET: { + struct sockaddr_in *sin = (struct sockaddr_in *)sap; + seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr); + break; + } + case AF_INET6: { + struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap; + seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr); + break; + } + default: + if (showdefaults) + seq_printf(m, ",mountaddr=unspecified"); + } + + if (nfss->mountd_version || showdefaults) + seq_printf(m, ",mountvers=%u", nfss->mountd_version); + if ((nfss->mountd_port && + nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) || + showdefaults) + seq_printf(m, ",mountport=%u", nfss->mountd_port); + + nfs_show_mountd_netid(m, nfss, showdefaults); +} + +#ifdef CONFIG_NFS_V4 +static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss, + int showdefaults) +{ + struct nfs_client *clp = nfss->nfs_client; + + seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr); +} +#else +static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss, + int showdefaults) +{ +} +#endif + +static void nfs_show_nfs_version(struct seq_file *m, + unsigned int version, + unsigned int minorversion) +{ + seq_printf(m, ",vers=%u", version); + if (version == 4) + seq_printf(m, ".%u", minorversion); +} + +/* + * Describe the mount options in force on this server representation + */ +static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, + int showdefaults) +{ + static const struct proc_nfs_info { + int flag; + const char *str; + const char *nostr; + } nfs_info[] = { + { NFS_MOUNT_SOFT, ",soft", ",hard" }, + { NFS_MOUNT_POSIX, ",posix", "" }, + { NFS_MOUNT_NOCTO, ",nocto", "" }, + { NFS_MOUNT_NOAC, ",noac", "" }, + { NFS_MOUNT_NONLM, ",nolock", "" }, + { NFS_MOUNT_NOACL, ",noacl", "" }, + { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" }, + { NFS_MOUNT_UNSHARED, ",nosharecache", "" }, + { NFS_MOUNT_NORESVPORT, ",noresvport", "" }, + { 0, NULL, NULL } + }; + const struct proc_nfs_info *nfs_infop; + struct nfs_client *clp = nfss->nfs_client; + u32 version = clp->rpc_ops->version; + int local_flock, local_fcntl; + + nfs_show_nfs_version(m, version, clp->cl_minorversion); + seq_printf(m, ",rsize=%u", nfss->rsize); + seq_printf(m, ",wsize=%u", nfss->wsize); + if (nfss->bsize != 0) + seq_printf(m, ",bsize=%u", nfss->bsize); + seq_printf(m, ",namlen=%u", nfss->namelen); + if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults) + seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ); + if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults) + seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ); + if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults) + seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ); + if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults) + seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ); + for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) { + if (nfss->flags & nfs_infop->flag) + seq_puts(m, nfs_infop->str); + else + seq_puts(m, nfs_infop->nostr); + } + rcu_read_lock(); + seq_printf(m, ",proto=%s", + rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID)); + rcu_read_unlock(); + if (version == 4) { + if (nfss->port != NFS_PORT) + seq_printf(m, ",port=%u", nfss->port); + } else + if (nfss->port) + seq_printf(m, ",port=%u", nfss->port); + + seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ); + seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries); + seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor)); + + if (version != 4) + nfs_show_mountd_options(m, nfss, showdefaults); + else + nfs_show_nfsv4_options(m, nfss, showdefaults); + + if (nfss->options & NFS_OPTION_FSCACHE) + seq_printf(m, ",fsc"); + + if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) { + if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) + seq_printf(m, ",lookupcache=none"); + else + seq_printf(m, ",lookupcache=pos"); + } + + local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK; + local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL; + + if (!local_flock && !local_fcntl) + seq_printf(m, ",local_lock=none"); + else if (local_flock && local_fcntl) + seq_printf(m, ",local_lock=all"); + else if (local_flock) + seq_printf(m, ",local_lock=flock"); + else + seq_printf(m, ",local_lock=posix"); +} + +/* + * Describe the mount options on this VFS mountpoint + */ +static int nfs_show_options(struct seq_file *m, struct dentry *root) +{ + struct nfs_server *nfss = NFS_SB(root->d_sb); + + nfs_show_mount_options(m, nfss, 0); + + rcu_read_lock(); + seq_printf(m, ",addr=%s", + rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient, + RPC_DISPLAY_ADDR)); + rcu_read_unlock(); + + return 0; +} + +#ifdef CONFIG_NFS_V4 +#ifdef CONFIG_NFS_V4_1 +static void show_sessions(struct seq_file *m, struct nfs_server *server) +{ + if (nfs4_has_session(server->nfs_client)) + seq_printf(m, ",sessions"); +} +#else +static void show_sessions(struct seq_file *m, struct nfs_server *server) {} +#endif +#endif + +#ifdef CONFIG_NFS_V4_1 +static void show_pnfs(struct seq_file *m, struct nfs_server *server) +{ + seq_printf(m, ",pnfs="); + if (server->pnfs_curr_ld) + seq_printf(m, "%s", server->pnfs_curr_ld->name); + else + seq_printf(m, "not configured"); +} + +static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss) +{ + if (nfss->nfs_client && nfss->nfs_client->impl_id) { + struct nfs41_impl_id *impl_id = nfss->nfs_client->impl_id; + seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s'," + "date='%llu,%u'", + impl_id->name, impl_id->domain, + impl_id->date.seconds, impl_id->date.nseconds); + } +} +#else +#ifdef CONFIG_NFS_V4 +static void show_pnfs(struct seq_file *m, struct nfs_server *server) +{ +} +#endif +static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss) +{ +} +#endif + +static int nfs_show_devname(struct seq_file *m, struct dentry *root) +{ + char *page = (char *) __get_free_page(GFP_KERNEL); + char *devname, *dummy; + int err = 0; + if (!page) + return -ENOMEM; + devname = nfs_path(&dummy, root, page, PAGE_SIZE); + if (IS_ERR(devname)) + err = PTR_ERR(devname); + else + seq_escape(m, devname, " \t\n\\"); + free_page((unsigned long)page); + return err; +} + +static int nfs_show_path(struct seq_file *m, struct dentry *dentry) +{ + seq_puts(m, "/"); + return 0; +} + +/* + * Present statistical information for this VFS mountpoint + */ +static int nfs_show_stats(struct seq_file *m, struct dentry *root) +{ + int i, cpu; + struct nfs_server *nfss = NFS_SB(root->d_sb); + struct rpc_auth *auth = nfss->client->cl_auth; + struct nfs_iostats totals = { }; + + seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS); + + /* + * Display all mount option settings + */ + seq_printf(m, "\n\topts:\t"); + seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw"); + seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : ""); + seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : ""); + seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : ""); + nfs_show_mount_options(m, nfss, 1); + + seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ); + + show_implementation_id(m, nfss); + + seq_printf(m, "\n\tcaps:\t"); + seq_printf(m, "caps=0x%x", nfss->caps); + seq_printf(m, ",wtmult=%u", nfss->wtmult); + seq_printf(m, ",dtsize=%u", nfss->dtsize); + seq_printf(m, ",bsize=%u", nfss->bsize); + seq_printf(m, ",namlen=%u", nfss->namelen); + +#ifdef CONFIG_NFS_V4 + if (nfss->nfs_client->rpc_ops->version == 4) { + seq_printf(m, "\n\tnfsv4:\t"); + seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]); + seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]); + seq_printf(m, ",acl=0x%x", nfss->acl_bitmask); + show_sessions(m, nfss); + show_pnfs(m, nfss); + } +#endif + + /* + * Display security flavor in effect for this mount + */ + seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor); + if (auth->au_flavor) + seq_printf(m, ",pseudoflavor=%u", auth->au_flavor); + + /* + * Display superblock I/O counters + */ + for_each_possible_cpu(cpu) { + struct nfs_iostats *stats; + + preempt_disable(); + stats = per_cpu_ptr(nfss->io_stats, cpu); + + for (i = 0; i < __NFSIOS_COUNTSMAX; i++) + totals.events[i] += stats->events[i]; + for (i = 0; i < __NFSIOS_BYTESMAX; i++) + totals.bytes[i] += stats->bytes[i]; +#ifdef CONFIG_NFS_FSCACHE + for (i = 0; i < __NFSIOS_FSCACHEMAX; i++) + totals.fscache[i] += stats->fscache[i]; +#endif + + preempt_enable(); + } + + seq_printf(m, "\n\tevents:\t"); + for (i = 0; i < __NFSIOS_COUNTSMAX; i++) + seq_printf(m, "%lu ", totals.events[i]); + seq_printf(m, "\n\tbytes:\t"); + for (i = 0; i < __NFSIOS_BYTESMAX; i++) + seq_printf(m, "%Lu ", totals.bytes[i]); +#ifdef CONFIG_NFS_FSCACHE + if (nfss->options & NFS_OPTION_FSCACHE) { + seq_printf(m, "\n\tfsc:\t"); + for (i = 0; i < __NFSIOS_FSCACHEMAX; i++) + seq_printf(m, "%Lu ", totals.bytes[i]); + } +#endif + seq_printf(m, "\n"); + + rpc_print_iostats(m, nfss->client); + + return 0; +} + +/* + * Begin unmount by attempting to remove all automounted mountpoints we added + * in response to xdev traversals and referrals + */ +static void nfs_umount_begin(struct super_block *sb) +{ + struct nfs_server *server; + struct rpc_clnt *rpc; + + server = NFS_SB(sb); + /* -EIO all pending I/O */ + rpc = server->client_acl; + if (!IS_ERR(rpc)) + rpc_killall_tasks(rpc); + rpc = server->client; + if (!IS_ERR(rpc)) + rpc_killall_tasks(rpc); +} + +static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version) +{ + struct nfs_parsed_mount_data *data; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (data) { + data->acregmin = NFS_DEF_ACREGMIN; + data->acregmax = NFS_DEF_ACREGMAX; + data->acdirmin = NFS_DEF_ACDIRMIN; + data->acdirmax = NFS_DEF_ACDIRMAX; + data->mount_server.port = NFS_UNSPEC_PORT; + data->nfs_server.port = NFS_UNSPEC_PORT; + data->nfs_server.protocol = XPRT_TRANSPORT_TCP; + data->auth_flavors[0] = RPC_AUTH_UNIX; + data->auth_flavor_len = 1; + data->version = version; + data->minorversion = 0; + data->net = current->nsproxy->net_ns; + security_init_mnt_opts(&data->lsm_opts); + } + return data; +} + +static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data) +{ + if (data) { + kfree(data->client_address); + kfree(data->mount_server.hostname); + kfree(data->nfs_server.export_path); + kfree(data->nfs_server.hostname); + kfree(data->fscache_uniq); + security_free_mnt_opts(&data->lsm_opts); + kfree(data); + } +} + +/* + * Sanity-check a server address provided by the mount command. + * + * Address family must be initialized, and address must not be + * the ANY address for that family. + */ +static int nfs_verify_server_address(struct sockaddr *addr) +{ + switch (addr->sa_family) { + case AF_INET: { + struct sockaddr_in *sa = (struct sockaddr_in *)addr; + return sa->sin_addr.s_addr != htonl(INADDR_ANY); + } + case AF_INET6: { + struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr; + return !ipv6_addr_any(sa); + } + } + + dfprintk(MOUNT, "NFS: Invalid IP address specified\n"); + return 0; +} + +/* + * Select between a default port value and a user-specified port value. + * If a zero value is set, then autobind will be used. + */ +static void nfs_set_port(struct sockaddr *sap, int *port, + const unsigned short default_port) +{ + if (*port == NFS_UNSPEC_PORT) + *port = default_port; + + rpc_set_port(sap, *port); +} + +/* + * Sanity check the NFS transport protocol. + * + */ +static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt) +{ + switch (mnt->nfs_server.protocol) { + case XPRT_TRANSPORT_UDP: + case XPRT_TRANSPORT_TCP: + case XPRT_TRANSPORT_RDMA: + break; + default: + mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP; + } +} + +/* + * For text based NFSv2/v3 mounts, the mount protocol transport default + * settings should depend upon the specified NFS transport. + */ +static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt) +{ + nfs_validate_transport_protocol(mnt); + + if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP || + mnt->mount_server.protocol == XPRT_TRANSPORT_TCP) + return; + switch (mnt->nfs_server.protocol) { + case XPRT_TRANSPORT_UDP: + mnt->mount_server.protocol = XPRT_TRANSPORT_UDP; + break; + case XPRT_TRANSPORT_TCP: + case XPRT_TRANSPORT_RDMA: + mnt->mount_server.protocol = XPRT_TRANSPORT_TCP; + } +} + +/* + * Parse the value of the 'sec=' option. + */ +static int nfs_parse_security_flavors(char *value, + struct nfs_parsed_mount_data *mnt) +{ + substring_t args[MAX_OPT_ARGS]; + + dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value); + + switch (match_token(value, nfs_secflavor_tokens, args)) { + case Opt_sec_none: + mnt->auth_flavors[0] = RPC_AUTH_NULL; + break; + case Opt_sec_sys: + mnt->auth_flavors[0] = RPC_AUTH_UNIX; + break; + case Opt_sec_krb5: + mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5; + break; + case Opt_sec_krb5i: + mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I; + break; + case Opt_sec_krb5p: + mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P; + break; + case Opt_sec_lkey: + mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY; + break; + case Opt_sec_lkeyi: + mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI; + break; + case Opt_sec_lkeyp: + mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP; + break; + case Opt_sec_spkm: + mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM; + break; + case Opt_sec_spkmi: + mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI; + break; + case Opt_sec_spkmp: + mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP; + break; + default: + return 0; + } + + mnt->flags |= NFS_MOUNT_SECFLAVOUR; + mnt->auth_flavor_len = 1; + return 1; +} + +static int nfs_parse_version_string(char *string, + struct nfs_parsed_mount_data *mnt, + substring_t *args) +{ + mnt->flags &= ~NFS_MOUNT_VER3; + switch (match_token(string, nfs_vers_tokens, args)) { + case Opt_vers_2: + mnt->version = 2; + break; + case Opt_vers_3: + mnt->flags |= NFS_MOUNT_VER3; + mnt->version = 3; + break; + case Opt_vers_4: + /* Backward compatibility option. In future, + * the mount program should always supply + * a NFSv4 minor version number. + */ + mnt->version = 4; + break; + case Opt_vers_4_0: + mnt->version = 4; + mnt->minorversion = 0; + break; + case Opt_vers_4_1: + mnt->version = 4; + mnt->minorversion = 1; + break; + default: + return 0; + } + return 1; +} + +static int nfs_get_option_str(substring_t args[], char **option) +{ + kfree(*option); + *option = match_strdup(args); + return !option; +} + +static int nfs_get_option_ul(substring_t args[], unsigned long *option) +{ + int rc; + char *string; + + string = match_strdup(args); + if (string == NULL) + return -ENOMEM; + rc = strict_strtoul(string, 10, option); + kfree(string); + + return rc; +} + +/* + * Error-check and convert a string of mount options from user space into + * a data structure. The whole mount string is processed; bad options are + * skipped as they are encountered. If there were no errors, return 1; + * otherwise return 0 (zero). + */ +static int nfs_parse_mount_options(char *raw, + struct nfs_parsed_mount_data *mnt) +{ + char *p, *string, *secdata; + int rc, sloppy = 0, invalid_option = 0; + unsigned short protofamily = AF_UNSPEC; + unsigned short mountfamily = AF_UNSPEC; + + if (!raw) { + dfprintk(MOUNT, "NFS: mount options string was NULL.\n"); + return 1; + } + dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw); + + secdata = alloc_secdata(); + if (!secdata) + goto out_nomem; + + rc = security_sb_copy_data(raw, secdata); + if (rc) + goto out_security_failure; + + rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts); + if (rc) + goto out_security_failure; + + free_secdata(secdata); + + while ((p = strsep(&raw, ",")) != NULL) { + substring_t args[MAX_OPT_ARGS]; + unsigned long option; + int token; + + if (!*p) + continue; + + dfprintk(MOUNT, "NFS: parsing nfs mount option '%s'\n", p); + + token = match_token(p, nfs_mount_option_tokens, args); + switch (token) { + + /* + * boolean options: foo/nofoo + */ + case Opt_soft: + mnt->flags |= NFS_MOUNT_SOFT; + break; + case Opt_hard: + mnt->flags &= ~NFS_MOUNT_SOFT; + break; + case Opt_posix: + mnt->flags |= NFS_MOUNT_POSIX; + break; + case Opt_noposix: + mnt->flags &= ~NFS_MOUNT_POSIX; + break; + case Opt_cto: + mnt->flags &= ~NFS_MOUNT_NOCTO; + break; + case Opt_nocto: + mnt->flags |= NFS_MOUNT_NOCTO; + break; + case Opt_ac: + mnt->flags &= ~NFS_MOUNT_NOAC; + break; + case Opt_noac: + mnt->flags |= NFS_MOUNT_NOAC; + break; + case Opt_lock: + mnt->flags &= ~NFS_MOUNT_NONLM; + mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | + NFS_MOUNT_LOCAL_FCNTL); + break; + case Opt_nolock: + mnt->flags |= NFS_MOUNT_NONLM; + mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK | + NFS_MOUNT_LOCAL_FCNTL); + break; + case Opt_udp: + mnt->flags &= ~NFS_MOUNT_TCP; + mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP; + break; + case Opt_tcp: + mnt->flags |= NFS_MOUNT_TCP; + mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP; + break; + case Opt_rdma: + mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */ + mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA; + xprt_load_transport(p); + break; + case Opt_acl: + mnt->flags &= ~NFS_MOUNT_NOACL; + break; + case Opt_noacl: + mnt->flags |= NFS_MOUNT_NOACL; + break; + case Opt_rdirplus: + mnt->flags &= ~NFS_MOUNT_NORDIRPLUS; + break; + case Opt_nordirplus: + mnt->flags |= NFS_MOUNT_NORDIRPLUS; + break; + case Opt_sharecache: + mnt->flags &= ~NFS_MOUNT_UNSHARED; + break; + case Opt_nosharecache: + mnt->flags |= NFS_MOUNT_UNSHARED; + break; + case Opt_resvport: + mnt->flags &= ~NFS_MOUNT_NORESVPORT; + break; + case Opt_noresvport: + mnt->flags |= NFS_MOUNT_NORESVPORT; + break; + case Opt_fscache: + mnt->options |= NFS_OPTION_FSCACHE; + kfree(mnt->fscache_uniq); + mnt->fscache_uniq = NULL; + break; + case Opt_nofscache: + mnt->options &= ~NFS_OPTION_FSCACHE; + kfree(mnt->fscache_uniq); + mnt->fscache_uniq = NULL; + break; + + /* + * options that take numeric values + */ + case Opt_port: + if (nfs_get_option_ul(args, &option) || + option > USHRT_MAX) + goto out_invalid_value; + mnt->nfs_server.port = option; + break; + case Opt_rsize: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->rsize = option; + break; + case Opt_wsize: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->wsize = option; + break; + case Opt_bsize: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->bsize = option; + break; + case Opt_timeo: + if (nfs_get_option_ul(args, &option) || option == 0) + goto out_invalid_value; + mnt->timeo = option; + break; + case Opt_retrans: + if (nfs_get_option_ul(args, &option) || option == 0) + goto out_invalid_value; + mnt->retrans = option; + break; + case Opt_acregmin: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->acregmin = option; + break; + case Opt_acregmax: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->acregmax = option; + break; + case Opt_acdirmin: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->acdirmin = option; + break; + case Opt_acdirmax: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->acdirmax = option; + break; + case Opt_actimeo: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->acregmin = mnt->acregmax = + mnt->acdirmin = mnt->acdirmax = option; + break; + case Opt_namelen: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + mnt->namlen = option; + break; + case Opt_mountport: + if (nfs_get_option_ul(args, &option) || + option > USHRT_MAX) + goto out_invalid_value; + mnt->mount_server.port = option; + break; + case Opt_mountvers: + if (nfs_get_option_ul(args, &option) || + option < NFS_MNT_VERSION || + option > NFS_MNT3_VERSION) + goto out_invalid_value; + mnt->mount_server.version = option; + break; + case Opt_minorversion: + if (nfs_get_option_ul(args, &option)) + goto out_invalid_value; + if (option > NFS4_MAX_MINOR_VERSION) + goto out_invalid_value; + mnt->minorversion = option; + break; + + /* + * options that take text values + */ + case Opt_nfsvers: + string = match_strdup(args); + if (string == NULL) + goto out_nomem; + rc = nfs_parse_version_string(string, mnt, args); + kfree(string); + if (!rc) + goto out_invalid_value; + break; + case Opt_sec: + string = match_strdup(args); + if (string == NULL) + goto out_nomem; + rc = nfs_parse_security_flavors(string, mnt); + kfree(string); + if (!rc) { + dfprintk(MOUNT, "NFS: unrecognized " + "security flavor\n"); + return 0; + } + break; + case Opt_proto: + string = match_strdup(args); + if (string == NULL) + goto out_nomem; + token = match_token(string, + nfs_xprt_protocol_tokens, args); + + protofamily = AF_INET; + switch (token) { + case Opt_xprt_udp6: + protofamily = AF_INET6; + case Opt_xprt_udp: + mnt->flags &= ~NFS_MOUNT_TCP; + mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP; + break; + case Opt_xprt_tcp6: + protofamily = AF_INET6; + case Opt_xprt_tcp: + mnt->flags |= NFS_MOUNT_TCP; + mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP; + break; + case Opt_xprt_rdma: + /* vector side protocols to TCP */ + mnt->flags |= NFS_MOUNT_TCP; + mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA; + xprt_load_transport(string); + break; + default: + dfprintk(MOUNT, "NFS: unrecognized " + "transport protocol\n"); + kfree(string); + return 0; + } + kfree(string); + break; + case Opt_mountproto: + string = match_strdup(args); + if (string == NULL) + goto out_nomem; + token = match_token(string, + nfs_xprt_protocol_tokens, args); + kfree(string); + + mountfamily = AF_INET; + switch (token) { + case Opt_xprt_udp6: + mountfamily = AF_INET6; + case Opt_xprt_udp: + mnt->mount_server.protocol = XPRT_TRANSPORT_UDP; + break; + case Opt_xprt_tcp6: + mountfamily = AF_INET6; + case Opt_xprt_tcp: + mnt->mount_server.protocol = XPRT_TRANSPORT_TCP; + break; + case Opt_xprt_rdma: /* not used for side protocols */ + default: + dfprintk(MOUNT, "NFS: unrecognized " + "transport protocol\n"); + return 0; + } + break; + case Opt_addr: + string = match_strdup(args); + if (string == NULL) + goto out_nomem; + mnt->nfs_server.addrlen = + rpc_pton(mnt->net, string, strlen(string), + (struct sockaddr *) + &mnt->nfs_server.address, + sizeof(mnt->nfs_server.address)); + kfree(string); + if (mnt->nfs_server.addrlen == 0) + goto out_invalid_address; + break; + case Opt_clientaddr: + if (nfs_get_option_str(args, &mnt->client_address)) + goto out_nomem; + break; + case Opt_mounthost: + if (nfs_get_option_str(args, + &mnt->mount_server.hostname)) + goto out_nomem; + break; + case Opt_mountaddr: + string = match_strdup(args); + if (string == NULL) + goto out_nomem; + mnt->mount_server.addrlen = + rpc_pton(mnt->net, string, strlen(string), + (struct sockaddr *) + &mnt->mount_server.address, + sizeof(mnt->mount_server.address)); + kfree(string); + if (mnt->mount_server.addrlen == 0) + goto out_invalid_address; + break; + case Opt_lookupcache: + string = match_strdup(args); + if (string == NULL) + goto out_nomem; + token = match_token(string, + nfs_lookupcache_tokens, args); + kfree(string); + switch (token) { + case Opt_lookupcache_all: + mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE); + break; + case Opt_lookupcache_positive: + mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE; + mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG; + break; + case Opt_lookupcache_none: + mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE; + break; + default: + dfprintk(MOUNT, "NFS: invalid " + "lookupcache argument\n"); + return 0; + }; + break; + case Opt_fscache_uniq: + if (nfs_get_option_str(args, &mnt->fscache_uniq)) + goto out_nomem; + mnt->options |= NFS_OPTION_FSCACHE; + break; + case Opt_local_lock: + string = match_strdup(args); + if (string == NULL) + goto out_nomem; + token = match_token(string, nfs_local_lock_tokens, + args); + kfree(string); + switch (token) { + case Opt_local_lock_all: + mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK | + NFS_MOUNT_LOCAL_FCNTL); + break; + case Opt_local_lock_flock: + mnt->flags |= NFS_MOUNT_LOCAL_FLOCK; + break; + case Opt_local_lock_posix: + mnt->flags |= NFS_MOUNT_LOCAL_FCNTL; + break; + case Opt_local_lock_none: + mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | + NFS_MOUNT_LOCAL_FCNTL); + break; + default: + dfprintk(MOUNT, "NFS: invalid " + "local_lock argument\n"); + return 0; + }; + break; + + /* + * Special options + */ + case Opt_sloppy: + sloppy = 1; + dfprintk(MOUNT, "NFS: relaxing parsing rules\n"); + break; + case Opt_userspace: + case Opt_deprecated: + dfprintk(MOUNT, "NFS: ignoring mount option " + "'%s'\n", p); + break; + + default: + invalid_option = 1; + dfprintk(MOUNT, "NFS: unrecognized mount option " + "'%s'\n", p); + } + } + + if (!sloppy && invalid_option) + return 0; + + if (mnt->minorversion && mnt->version != 4) + goto out_minorversion_mismatch; + + /* + * verify that any proto=/mountproto= options match the address + * familiies in the addr=/mountaddr= options. + */ + if (protofamily != AF_UNSPEC && + protofamily != mnt->nfs_server.address.ss_family) + goto out_proto_mismatch; + + if (mountfamily != AF_UNSPEC) { + if (mnt->mount_server.addrlen) { + if (mountfamily != mnt->mount_server.address.ss_family) + goto out_mountproto_mismatch; + } else { + if (mountfamily != mnt->nfs_server.address.ss_family) + goto out_mountproto_mismatch; + } + } + + return 1; + +out_mountproto_mismatch: + printk(KERN_INFO "NFS: mount server address does not match mountproto= " + "option\n"); + return 0; +out_proto_mismatch: + printk(KERN_INFO "NFS: server address does not match proto= option\n"); + return 0; +out_invalid_address: + printk(KERN_INFO "NFS: bad IP address specified: %s\n", p); + return 0; +out_invalid_value: + printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p); + return 0; +out_minorversion_mismatch: + printk(KERN_INFO "NFS: mount option vers=%u does not support " + "minorversion=%u\n", mnt->version, mnt->minorversion); + return 0; +out_nomem: + printk(KERN_INFO "NFS: not enough memory to parse option\n"); + return 0; +out_security_failure: + free_secdata(secdata); + printk(KERN_INFO "NFS: security options invalid: %d\n", rc); + return 0; +} + +/* + * Match the requested auth flavors with the list returned by + * the server. Returns zero and sets the mount's authentication + * flavor on success; returns -EACCES if server does not support + * the requested flavor. + */ +static int nfs_walk_authlist(struct nfs_parsed_mount_data *args, + struct nfs_mount_request *request) +{ + unsigned int i, j, server_authlist_len = *(request->auth_flav_len); + + /* + * Certain releases of Linux's mountd return an empty + * flavor list. To prevent behavioral regression with + * these servers (ie. rejecting mounts that used to + * succeed), revert to pre-2.6.32 behavior (no checking) + * if the returned flavor list is empty. + */ + if (server_authlist_len == 0) + return 0; + + /* + * We avoid sophisticated negotiating here, as there are + * plenty of cases where we can get it wrong, providing + * either too little or too much security. + * + * RFC 2623, section 2.7 suggests we SHOULD prefer the + * flavor listed first. However, some servers list + * AUTH_NULL first. Our caller plants AUTH_SYS, the + * preferred default, in args->auth_flavors[0] if user + * didn't specify sec= mount option. + */ + for (i = 0; i < args->auth_flavor_len; i++) + for (j = 0; j < server_authlist_len; j++) + if (args->auth_flavors[i] == request->auth_flavs[j]) { + dfprintk(MOUNT, "NFS: using auth flavor %d\n", + request->auth_flavs[j]); + args->auth_flavors[0] = request->auth_flavs[j]; + return 0; + } + + dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n"); + nfs_umount(request); + return -EACCES; +} + +/* + * Use the remote server's MOUNT service to request the NFS file handle + * corresponding to the provided path. + */ +static int nfs_try_mount(struct nfs_parsed_mount_data *args, + struct nfs_fh *root_fh) +{ + rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS]; + unsigned int server_authlist_len = ARRAY_SIZE(server_authlist); + struct nfs_mount_request request = { + .sap = (struct sockaddr *) + &args->mount_server.address, + .dirpath = args->nfs_server.export_path, + .protocol = args->mount_server.protocol, + .fh = root_fh, + .noresvport = args->flags & NFS_MOUNT_NORESVPORT, + .auth_flav_len = &server_authlist_len, + .auth_flavs = server_authlist, + .net = args->net, + }; + int status; + + if (args->mount_server.version == 0) { + switch (args->version) { + default: + args->mount_server.version = NFS_MNT3_VERSION; + break; + case 2: + args->mount_server.version = NFS_MNT_VERSION; + } + } + request.version = args->mount_server.version; + + if (args->mount_server.hostname) + request.hostname = args->mount_server.hostname; + else + request.hostname = args->nfs_server.hostname; + + /* + * Construct the mount server's address. + */ + if (args->mount_server.address.ss_family == AF_UNSPEC) { + memcpy(request.sap, &args->nfs_server.address, + args->nfs_server.addrlen); + args->mount_server.addrlen = args->nfs_server.addrlen; + } + request.salen = args->mount_server.addrlen; + nfs_set_port(request.sap, &args->mount_server.port, 0); + + /* + * Now ask the mount server to map our export path + * to a file handle. + */ + status = nfs_mount(&request); + if (status != 0) { + dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n", + request.hostname, status); + return status; + } + + /* + * MNTv1 (NFSv2) does not support auth flavor negotiation. + */ + if (args->mount_server.version != NFS_MNT3_VERSION) + return 0; + return nfs_walk_authlist(args, &request); +} + +/* + * Split "dev_name" into "hostname:export_path". + * + * The leftmost colon demarks the split between the server's hostname + * and the export path. If the hostname starts with a left square + * bracket, then it may contain colons. + * + * Note: caller frees hostname and export path, even on error. + */ +static int nfs_parse_devname(const char *dev_name, + char **hostname, size_t maxnamlen, + char **export_path, size_t maxpathlen) +{ + size_t len; + char *end; + + /* Is the host name protected with square brakcets? */ + if (*dev_name == '[') { + end = strchr(++dev_name, ']'); + if (end == NULL || end[1] != ':') + goto out_bad_devname; + + len = end - dev_name; + end++; + } else { + char *comma; + + end = strchr(dev_name, ':'); + if (end == NULL) + goto out_bad_devname; + len = end - dev_name; + + /* kill possible hostname list: not supported */ + comma = strchr(dev_name, ','); + if (comma != NULL && comma < end) + *comma = 0; + } + + if (len > maxnamlen) + goto out_hostname; + + /* N.B. caller will free nfs_server.hostname in all cases */ + *hostname = kstrndup(dev_name, len, GFP_KERNEL); + if (*hostname == NULL) + goto out_nomem; + len = strlen(++end); + if (len > maxpathlen) + goto out_path; + *export_path = kstrndup(end, len, GFP_KERNEL); + if (!*export_path) + goto out_nomem; + + dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path); + return 0; + +out_bad_devname: + dfprintk(MOUNT, "NFS: device name not in host:path format\n"); + return -EINVAL; + +out_nomem: + dfprintk(MOUNT, "NFS: not enough memory to parse device name\n"); + return -ENOMEM; + +out_hostname: + dfprintk(MOUNT, "NFS: server hostname too long\n"); + return -ENAMETOOLONG; + +out_path: + dfprintk(MOUNT, "NFS: export pathname too long\n"); + return -ENAMETOOLONG; +} + +/* + * Validate the NFS2/NFS3 mount data + * - fills in the mount root filehandle + * + * For option strings, user space handles the following behaviors: + * + * + DNS: mapping server host name to IP address ("addr=" option) + * + * + failure mode: how to behave if a mount request can't be handled + * immediately ("fg/bg" option) + * + * + retry: how often to retry a mount request ("retry=" option) + * + * + breaking back: trying proto=udp after proto=tcp, v2 after v3, + * mountproto=tcp after mountproto=udp, and so on + */ +static int nfs_validate_mount_data(void *options, + struct nfs_parsed_mount_data *args, + struct nfs_fh *mntfh, + const char *dev_name) +{ + struct nfs_mount_data *data = (struct nfs_mount_data *)options; + struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address; + + if (data == NULL) + goto out_no_data; + + switch (data->version) { + case 1: + data->namlen = 0; + case 2: + data->bsize = 0; + case 3: + if (data->flags & NFS_MOUNT_VER3) + goto out_no_v3; + data->root.size = NFS2_FHSIZE; + memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE); + case 4: + if (data->flags & NFS_MOUNT_SECFLAVOUR) + goto out_no_sec; + case 5: + memset(data->context, 0, sizeof(data->context)); + case 6: + if (data->flags & NFS_MOUNT_VER3) { + if (data->root.size > NFS3_FHSIZE || data->root.size == 0) + goto out_invalid_fh; + mntfh->size = data->root.size; + args->version = 3; + } else { + mntfh->size = NFS2_FHSIZE; + args->version = 2; + } + + + memcpy(mntfh->data, data->root.data, mntfh->size); + if (mntfh->size < sizeof(mntfh->data)) + memset(mntfh->data + mntfh->size, 0, + sizeof(mntfh->data) - mntfh->size); + + /* + * Translate to nfs_parsed_mount_data, which nfs_fill_super + * can deal with. + */ + args->flags = data->flags & NFS_MOUNT_FLAGMASK; + args->flags |= NFS_MOUNT_LEGACY_INTERFACE; + args->rsize = data->rsize; + args->wsize = data->wsize; + args->timeo = data->timeo; + args->retrans = data->retrans; + args->acregmin = data->acregmin; + args->acregmax = data->acregmax; + args->acdirmin = data->acdirmin; + args->acdirmax = data->acdirmax; + + memcpy(sap, &data->addr, sizeof(data->addr)); + args->nfs_server.addrlen = sizeof(data->addr); + if (!nfs_verify_server_address(sap)) + goto out_no_address; + + if (!(data->flags & NFS_MOUNT_TCP)) + args->nfs_server.protocol = XPRT_TRANSPORT_UDP; + /* N.B. caller will free nfs_server.hostname in all cases */ + args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL); + args->namlen = data->namlen; + args->bsize = data->bsize; + + if (data->flags & NFS_MOUNT_SECFLAVOUR) + args->auth_flavors[0] = data->pseudoflavor; + if (!args->nfs_server.hostname) + goto out_nomem; + + if (!(data->flags & NFS_MOUNT_NONLM)) + args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK| + NFS_MOUNT_LOCAL_FCNTL); + else + args->flags |= (NFS_MOUNT_LOCAL_FLOCK| + NFS_MOUNT_LOCAL_FCNTL); + /* + * The legacy version 6 binary mount data from userspace has a + * field used only to transport selinux information into the + * the kernel. To continue to support that functionality we + * have a touch of selinux knowledge here in the NFS code. The + * userspace code converted context=blah to just blah so we are + * converting back to the full string selinux understands. + */ + if (data->context[0]){ +#ifdef CONFIG_SECURITY_SELINUX + int rc; + char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL); + if (!opts_str) + return -ENOMEM; + strcpy(opts_str, "context="); + data->context[NFS_MAX_CONTEXT_LEN] = '\0'; + strcat(opts_str, &data->context[0]); + rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts); + kfree(opts_str); + if (rc) + return rc; +#else + return -EINVAL; +#endif + } + + break; + default: { + int status; + + if (nfs_parse_mount_options((char *)options, args) == 0) + return -EINVAL; + + if (!nfs_verify_server_address(sap)) + goto out_no_address; + + if (args->version == 4) +#ifdef CONFIG_NFS_V4 + return nfs4_validate_text_mount_data(options, + args, dev_name); +#else + goto out_v4_not_compiled; +#endif + + nfs_set_port(sap, &args->nfs_server.port, 0); + + nfs_set_mount_transport_protocol(args); + + status = nfs_parse_devname(dev_name, + &args->nfs_server.hostname, + PAGE_SIZE, + &args->nfs_server.export_path, + NFS_MAXPATHLEN); + if (!status) + status = nfs_try_mount(args, mntfh); + + kfree(args->nfs_server.export_path); + args->nfs_server.export_path = NULL; + + if (status) + return status; + + break; + } + } + +#ifndef CONFIG_NFS_V3 + if (args->version == 3) + goto out_v3_not_compiled; +#endif /* !CONFIG_NFS_V3 */ + + return 0; + +out_no_data: + dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n"); + return -EINVAL; + +out_no_v3: + dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n", + data->version); + return -EINVAL; + +out_no_sec: + dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n"); + return -EINVAL; + +#ifndef CONFIG_NFS_V3 +out_v3_not_compiled: + dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n"); + return -EPROTONOSUPPORT; +#endif /* !CONFIG_NFS_V3 */ + +#ifndef CONFIG_NFS_V4 +out_v4_not_compiled: + dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n"); + return -EPROTONOSUPPORT; +#endif /* !CONFIG_NFS_V4 */ + +out_nomem: + dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n"); + return -ENOMEM; + +out_no_address: + dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n"); + return -EINVAL; + +out_invalid_fh: + dfprintk(MOUNT, "NFS: invalid root filehandle\n"); + return -EINVAL; +} + +static int +nfs_compare_remount_data(struct nfs_server *nfss, + struct nfs_parsed_mount_data *data) +{ + if (data->flags != nfss->flags || + data->rsize != nfss->rsize || + data->wsize != nfss->wsize || + data->retrans != nfss->client->cl_timeout->to_retries || + data->auth_flavors[0] != nfss->client->cl_auth->au_flavor || + data->acregmin != nfss->acregmin / HZ || + data->acregmax != nfss->acregmax / HZ || + data->acdirmin != nfss->acdirmin / HZ || + data->acdirmax != nfss->acdirmax / HZ || + data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) || + data->nfs_server.port != nfss->port || + data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen || + !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address, + (struct sockaddr *)&nfss->nfs_client->cl_addr)) + return -EINVAL; + + return 0; +} + +static int +nfs_remount(struct super_block *sb, int *flags, char *raw_data) +{ + int error; + struct nfs_server *nfss = sb->s_fs_info; + struct nfs_parsed_mount_data *data; + struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data; + struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data; + u32 nfsvers = nfss->nfs_client->rpc_ops->version; + + /* + * Userspace mount programs that send binary options generally send + * them populated with default values. We have no way to know which + * ones were explicitly specified. Fall back to legacy behavior and + * just return success. + */ + if ((nfsvers == 4 && (!options4 || options4->version == 1)) || + (nfsvers <= 3 && (!options || (options->version >= 1 && + options->version <= 6)))) + return 0; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + /* fill out struct with values from existing mount */ + data->flags = nfss->flags; + data->rsize = nfss->rsize; + data->wsize = nfss->wsize; + data->retrans = nfss->client->cl_timeout->to_retries; + data->auth_flavors[0] = nfss->client->cl_auth->au_flavor; + data->acregmin = nfss->acregmin / HZ; + data->acregmax = nfss->acregmax / HZ; + data->acdirmin = nfss->acdirmin / HZ; + data->acdirmax = nfss->acdirmax / HZ; + data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ; + data->nfs_server.port = nfss->port; + data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen; + memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr, + data->nfs_server.addrlen); + + /* overwrite those values with any that were specified */ + error = nfs_parse_mount_options((char *)options, data); + if (error < 0) + goto out; + + /* + * noac is a special case. It implies -o sync, but that's not + * necessarily reflected in the mtab options. do_remount_sb + * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the + * remount options, so we have to explicitly reset it. + */ + if (data->flags & NFS_MOUNT_NOAC) + *flags |= MS_SYNCHRONOUS; + + /* compare new mount options with old ones */ + error = nfs_compare_remount_data(nfss, data); +out: + kfree(data); + return error; +} + +/* + * Initialise the common bits of the superblock + */ +static inline void nfs_initialise_sb(struct super_block *sb) +{ + struct nfs_server *server = NFS_SB(sb); + + sb->s_magic = NFS_SUPER_MAGIC; + + /* We probably want something more informative here */ + snprintf(sb->s_id, sizeof(sb->s_id), + "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev)); + + if (sb->s_blocksize == 0) + sb->s_blocksize = nfs_block_bits(server->wsize, + &sb->s_blocksize_bits); + + sb->s_bdi = &server->backing_dev_info; + + nfs_super_set_maxbytes(sb, server->maxfilesize); +} + +/* + * Finish setting up an NFS2/3 superblock + */ +static void nfs_fill_super(struct super_block *sb, + struct nfs_parsed_mount_data *data) +{ + struct nfs_server *server = NFS_SB(sb); + + sb->s_blocksize_bits = 0; + sb->s_blocksize = 0; + if (data->bsize) + sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits); + + if (server->nfs_client->rpc_ops->version == 3) { + /* The VFS shouldn't apply the umask to mode bits. We will do + * so ourselves when necessary. + */ + sb->s_flags |= MS_POSIXACL; + sb->s_time_gran = 1; + } + + sb->s_op = &nfs_sops; + nfs_initialise_sb(sb); +} + +/* + * Finish setting up a cloned NFS2/3 superblock + */ +static void nfs_clone_super(struct super_block *sb, + const struct super_block *old_sb) +{ + struct nfs_server *server = NFS_SB(sb); + + sb->s_blocksize_bits = old_sb->s_blocksize_bits; + sb->s_blocksize = old_sb->s_blocksize; + sb->s_maxbytes = old_sb->s_maxbytes; + + if (server->nfs_client->rpc_ops->version == 3) { + /* The VFS shouldn't apply the umask to mode bits. We will do + * so ourselves when necessary. + */ + sb->s_flags |= MS_POSIXACL; + sb->s_time_gran = 1; + } + + sb->s_op = old_sb->s_op; + nfs_initialise_sb(sb); +} + +static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags) +{ + const struct nfs_server *a = s->s_fs_info; + const struct rpc_clnt *clnt_a = a->client; + const struct rpc_clnt *clnt_b = b->client; + + if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK)) + goto Ebusy; + if (a->nfs_client != b->nfs_client) + goto Ebusy; + if (a->flags != b->flags) + goto Ebusy; + if (a->wsize != b->wsize) + goto Ebusy; + if (a->rsize != b->rsize) + goto Ebusy; + if (a->acregmin != b->acregmin) + goto Ebusy; + if (a->acregmax != b->acregmax) + goto Ebusy; + if (a->acdirmin != b->acdirmin) + goto Ebusy; + if (a->acdirmax != b->acdirmax) + goto Ebusy; + if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor) + goto Ebusy; + return 1; +Ebusy: + return 0; +} + +struct nfs_sb_mountdata { + struct nfs_server *server; + int mntflags; +}; + +static int nfs_set_super(struct super_block *s, void *data) +{ + struct nfs_sb_mountdata *sb_mntdata = data; + struct nfs_server *server = sb_mntdata->server; + int ret; + + s->s_flags = sb_mntdata->mntflags; + s->s_fs_info = server; + s->s_d_op = server->nfs_client->rpc_ops->dentry_ops; + ret = set_anon_super(s, server); + if (ret == 0) + server->s_dev = s->s_dev; + return ret; +} + +static int nfs_compare_super_address(struct nfs_server *server1, + struct nfs_server *server2) +{ + struct sockaddr *sap1, *sap2; + + sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr; + sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr; + + if (sap1->sa_family != sap2->sa_family) + return 0; + + switch (sap1->sa_family) { + case AF_INET: { + struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1; + struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2; + if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr) + return 0; + if (sin1->sin_port != sin2->sin_port) + return 0; + break; + } + case AF_INET6: { + struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1; + struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2; + if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr)) + return 0; + if (sin1->sin6_port != sin2->sin6_port) + return 0; + break; + } + default: + return 0; + } + + return 1; +} + +static int nfs_compare_super(struct super_block *sb, void *data) +{ + struct nfs_sb_mountdata *sb_mntdata = data; + struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb); + int mntflags = sb_mntdata->mntflags; + + if (!nfs_compare_super_address(old, server)) + return 0; + /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */ + if (old->flags & NFS_MOUNT_UNSHARED) + return 0; + if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0) + return 0; + return nfs_compare_mount_options(sb, server, mntflags); +} + +static int nfs_bdi_register(struct nfs_server *server) +{ + return bdi_register_dev(&server->backing_dev_info, server->s_dev); +} + +static struct dentry *nfs_fs_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data) +{ + struct nfs_server *server = NULL; + struct super_block *s; + struct nfs_parsed_mount_data *data; + struct nfs_fh *mntfh; + struct dentry *mntroot = ERR_PTR(-ENOMEM); + int (*compare_super)(struct super_block *, void *) = nfs_compare_super; + struct nfs_sb_mountdata sb_mntdata = { + .mntflags = flags, + }; + int error; + + data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION); + mntfh = nfs_alloc_fhandle(); + if (data == NULL || mntfh == NULL) + goto out; + + /* Validate the mount data */ + error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name); + if (error < 0) { + mntroot = ERR_PTR(error); + goto out; + } + +#ifdef CONFIG_NFS_V4 + if (data->version == 4) { + mntroot = nfs4_try_mount(flags, dev_name, data); + goto out; + } +#endif /* CONFIG_NFS_V4 */ + + /* Get a volume representation */ + server = nfs_create_server(data, mntfh); + if (IS_ERR(server)) { + mntroot = ERR_CAST(server); + goto out; + } + sb_mntdata.server = server; + + if (server->flags & NFS_MOUNT_UNSHARED) + compare_super = NULL; + + /* -o noac implies -o sync */ + if (server->flags & NFS_MOUNT_NOAC) + sb_mntdata.mntflags |= MS_SYNCHRONOUS; + + /* Get a superblock - note that we may end up sharing one that already exists */ + s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata); + if (IS_ERR(s)) { + mntroot = ERR_CAST(s); + goto out_err_nosb; + } + + if (s->s_fs_info != server) { + nfs_free_server(server); + server = NULL; + } else { + error = nfs_bdi_register(server); + if (error) { + mntroot = ERR_PTR(error); + goto error_splat_bdi; + } + } + + if (!s->s_root) { + /* initial superblock/root creation */ + nfs_fill_super(s, data); + nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL); + } + + mntroot = nfs_get_root(s, mntfh, dev_name); + if (IS_ERR(mntroot)) + goto error_splat_super; + + error = security_sb_set_mnt_opts(s, &data->lsm_opts); + if (error) + goto error_splat_root; + + s->s_flags |= MS_ACTIVE; + +out: + nfs_free_parsed_mount_data(data); + nfs_free_fhandle(mntfh); + return mntroot; + +out_err_nosb: + nfs_free_server(server); + goto out; + +error_splat_root: + dput(mntroot); + mntroot = ERR_PTR(error); +error_splat_super: + if (server && !s->s_root) + bdi_unregister(&server->backing_dev_info); +error_splat_bdi: + deactivate_locked_super(s); + goto out; +} + +/* + * Ensure that we unregister the bdi before kill_anon_super + * releases the device name + */ +static void nfs_put_super(struct super_block *s) +{ + struct nfs_server *server = NFS_SB(s); + + bdi_unregister(&server->backing_dev_info); +} + +/* + * Destroy an NFS2/3 superblock + */ +static void nfs_kill_super(struct super_block *s) +{ + struct nfs_server *server = NFS_SB(s); + + kill_anon_super(s); + nfs_fscache_release_super_cookie(s); + nfs_free_server(server); +} + +/* + * Clone an NFS2/3 server record on xdev traversal (FSID-change) + */ +static struct dentry * +nfs_xdev_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data) +{ + struct nfs_clone_mount *data = raw_data; + struct super_block *s; + struct nfs_server *server; + struct dentry *mntroot; + int (*compare_super)(struct super_block *, void *) = nfs_compare_super; + struct nfs_sb_mountdata sb_mntdata = { + .mntflags = flags, + }; + int error; + + dprintk("--> nfs_xdev_mount()\n"); + + /* create a new volume representation */ + server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor); + if (IS_ERR(server)) { + error = PTR_ERR(server); + goto out_err_noserver; + } + sb_mntdata.server = server; + + if (server->flags & NFS_MOUNT_UNSHARED) + compare_super = NULL; + + /* -o noac implies -o sync */ + if (server->flags & NFS_MOUNT_NOAC) + sb_mntdata.mntflags |= MS_SYNCHRONOUS; + + /* Get a superblock - note that we may end up sharing one that already exists */ + s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata); + if (IS_ERR(s)) { + error = PTR_ERR(s); + goto out_err_nosb; + } + + if (s->s_fs_info != server) { + nfs_free_server(server); + server = NULL; + } else { + error = nfs_bdi_register(server); + if (error) + goto error_splat_bdi; + } + + if (!s->s_root) { + /* initial superblock/root creation */ + nfs_clone_super(s, data->sb); + nfs_fscache_get_super_cookie(s, NULL, data); + } + + mntroot = nfs_get_root(s, data->fh, dev_name); + if (IS_ERR(mntroot)) { + error = PTR_ERR(mntroot); + goto error_splat_super; + } + if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) { + dput(mntroot); + error = -ESTALE; + goto error_splat_super; + } + + s->s_flags |= MS_ACTIVE; + + /* clone any lsm security options from the parent to the new sb */ + security_sb_clone_mnt_opts(data->sb, s); + + dprintk("<-- nfs_xdev_mount() = 0\n"); + return mntroot; + +out_err_nosb: + nfs_free_server(server); +out_err_noserver: + dprintk("<-- nfs_xdev_mount() = %d [error]\n", error); + return ERR_PTR(error); + +error_splat_super: + if (server && !s->s_root) + bdi_unregister(&server->backing_dev_info); +error_splat_bdi: + deactivate_locked_super(s); + dprintk("<-- nfs_xdev_mount() = %d [splat]\n", error); + return ERR_PTR(error); +} + +#ifdef CONFIG_NFS_V4 + +/* + * Finish setting up a cloned NFS4 superblock + */ +static void nfs4_clone_super(struct super_block *sb, + const struct super_block *old_sb) +{ + sb->s_blocksize_bits = old_sb->s_blocksize_bits; + sb->s_blocksize = old_sb->s_blocksize; + sb->s_maxbytes = old_sb->s_maxbytes; + sb->s_time_gran = 1; + sb->s_op = old_sb->s_op; + /* + * The VFS shouldn't apply the umask to mode bits. We will do + * so ourselves when necessary. + */ + sb->s_flags |= MS_POSIXACL; + sb->s_xattr = old_sb->s_xattr; + nfs_initialise_sb(sb); +} + +/* + * Set up an NFS4 superblock + */ +static void nfs4_fill_super(struct super_block *sb) +{ + sb->s_time_gran = 1; + sb->s_op = &nfs4_sops; + /* + * The VFS shouldn't apply the umask to mode bits. We will do + * so ourselves when necessary. + */ + sb->s_flags |= MS_POSIXACL; + sb->s_xattr = nfs4_xattr_handlers; + nfs_initialise_sb(sb); +} + +static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args) +{ + args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3| + NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL); +} + +static int nfs4_validate_text_mount_data(void *options, + struct nfs_parsed_mount_data *args, + const char *dev_name) +{ + struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address; + + nfs_set_port(sap, &args->nfs_server.port, NFS_PORT); + + nfs_validate_transport_protocol(args); + + nfs4_validate_mount_flags(args); + + if (args->version != 4) { + dfprintk(MOUNT, + "NFS4: Illegal mount version\n"); + return -EINVAL; + } + + if (args->auth_flavor_len > 1) { + dfprintk(MOUNT, + "NFS4: Too many RPC auth flavours specified\n"); + return -EINVAL; + } + + return nfs_parse_devname(dev_name, + &args->nfs_server.hostname, + NFS4_MAXNAMLEN, + &args->nfs_server.export_path, + NFS4_MAXPATHLEN); +} + +/* + * Validate NFSv4 mount options + */ +static int nfs4_validate_mount_data(void *options, + struct nfs_parsed_mount_data *args, + const char *dev_name) +{ + struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address; + struct nfs4_mount_data *data = (struct nfs4_mount_data *)options; + char *c; + + if (data == NULL) + goto out_no_data; + + switch (data->version) { + case 1: + if (data->host_addrlen > sizeof(args->nfs_server.address)) + goto out_no_address; + if (data->host_addrlen == 0) + goto out_no_address; + args->nfs_server.addrlen = data->host_addrlen; + if (copy_from_user(sap, data->host_addr, data->host_addrlen)) + return -EFAULT; + if (!nfs_verify_server_address(sap)) + goto out_no_address; + + if (data->auth_flavourlen) { + if (data->auth_flavourlen > 1) + goto out_inval_auth; + if (copy_from_user(&args->auth_flavors[0], + data->auth_flavours, + sizeof(args->auth_flavors[0]))) + return -EFAULT; + } + + c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN); + if (IS_ERR(c)) + return PTR_ERR(c); + args->nfs_server.hostname = c; + + c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN); + if (IS_ERR(c)) + return PTR_ERR(c); + args->nfs_server.export_path = c; + dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c); + + c = strndup_user(data->client_addr.data, 16); + if (IS_ERR(c)) + return PTR_ERR(c); + args->client_address = c; + + /* + * Translate to nfs_parsed_mount_data, which nfs4_fill_super + * can deal with. + */ + + args->flags = data->flags & NFS4_MOUNT_FLAGMASK; + args->rsize = data->rsize; + args->wsize = data->wsize; + args->timeo = data->timeo; + args->retrans = data->retrans; + args->acregmin = data->acregmin; + args->acregmax = data->acregmax; + args->acdirmin = data->acdirmin; + args->acdirmax = data->acdirmax; + args->nfs_server.protocol = data->proto; + nfs_validate_transport_protocol(args); + + break; + default: + if (nfs_parse_mount_options((char *)options, args) == 0) + return -EINVAL; + + if (!nfs_verify_server_address(sap)) + return -EINVAL; + + return nfs4_validate_text_mount_data(options, args, dev_name); + } + + return 0; + +out_no_data: + dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n"); + return -EINVAL; + +out_inval_auth: + dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n", + data->auth_flavourlen); + return -EINVAL; + +out_no_address: + dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n"); + return -EINVAL; +} + +/* + * Get the superblock for the NFS4 root partition + */ +static struct dentry * +nfs4_remote_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data) +{ + struct nfs_parsed_mount_data *data = raw_data; + struct super_block *s; + struct nfs_server *server; + struct nfs_fh *mntfh; + struct dentry *mntroot; + int (*compare_super)(struct super_block *, void *) = nfs_compare_super; + struct nfs_sb_mountdata sb_mntdata = { + .mntflags = flags, + }; + int error = -ENOMEM; + + mntfh = nfs_alloc_fhandle(); + if (data == NULL || mntfh == NULL) + goto out; + + /* Get a volume representation */ + server = nfs4_create_server(data, mntfh); + if (IS_ERR(server)) { + error = PTR_ERR(server); + goto out; + } + sb_mntdata.server = server; + + if (server->flags & NFS4_MOUNT_UNSHARED) + compare_super = NULL; + + /* -o noac implies -o sync */ + if (server->flags & NFS_MOUNT_NOAC) + sb_mntdata.mntflags |= MS_SYNCHRONOUS; + + /* Get a superblock - note that we may end up sharing one that already exists */ + s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata); + if (IS_ERR(s)) { + error = PTR_ERR(s); + goto out_free; + } + + if (s->s_fs_info != server) { + nfs_free_server(server); + server = NULL; + } else { + error = nfs_bdi_register(server); + if (error) + goto error_splat_bdi; + } + + if (!s->s_root) { + /* initial superblock/root creation */ + nfs4_fill_super(s); + nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL); + } + + mntroot = nfs4_get_root(s, mntfh, dev_name); + if (IS_ERR(mntroot)) { + error = PTR_ERR(mntroot); + goto error_splat_super; + } + + error = security_sb_set_mnt_opts(s, &data->lsm_opts); + if (error) + goto error_splat_root; + + s->s_flags |= MS_ACTIVE; + + nfs_free_fhandle(mntfh); + return mntroot; + +out: + nfs_free_fhandle(mntfh); + return ERR_PTR(error); + +out_free: + nfs_free_server(server); + goto out; + +error_splat_root: + dput(mntroot); +error_splat_super: + if (server && !s->s_root) + bdi_unregister(&server->backing_dev_info); +error_splat_bdi: + deactivate_locked_super(s); + goto out; +} + +static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type, + int flags, void *data, const char *hostname) +{ + struct vfsmount *root_mnt; + char *root_devname; + size_t len; + + len = strlen(hostname) + 5; + root_devname = kmalloc(len, GFP_KERNEL); + if (root_devname == NULL) + return ERR_PTR(-ENOMEM); + /* Does hostname needs to be enclosed in brackets? */ + if (strchr(hostname, ':')) + snprintf(root_devname, len, "[%s]:/", hostname); + else + snprintf(root_devname, len, "%s:/", hostname); + root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data); + kfree(root_devname); + return root_mnt; +} + +struct nfs_referral_count { + struct list_head list; + const struct task_struct *task; + unsigned int referral_count; +}; + +static LIST_HEAD(nfs_referral_count_list); +static DEFINE_SPINLOCK(nfs_referral_count_list_lock); + +static struct nfs_referral_count *nfs_find_referral_count(void) +{ + struct nfs_referral_count *p; + + list_for_each_entry(p, &nfs_referral_count_list, list) { + if (p->task == current) + return p; + } + return NULL; +} + +#define NFS_MAX_NESTED_REFERRALS 2 + +static int nfs_referral_loop_protect(void) +{ + struct nfs_referral_count *p, *new; + int ret = -ENOMEM; + + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) + goto out; + new->task = current; + new->referral_count = 1; + + ret = 0; + spin_lock(&nfs_referral_count_list_lock); + p = nfs_find_referral_count(); + if (p != NULL) { + if (p->referral_count >= NFS_MAX_NESTED_REFERRALS) + ret = -ELOOP; + else + p->referral_count++; + } else { + list_add(&new->list, &nfs_referral_count_list); + new = NULL; + } + spin_unlock(&nfs_referral_count_list_lock); + kfree(new); +out: + return ret; +} + +static void nfs_referral_loop_unprotect(void) +{ + struct nfs_referral_count *p; + + spin_lock(&nfs_referral_count_list_lock); + p = nfs_find_referral_count(); + p->referral_count--; + if (p->referral_count == 0) + list_del(&p->list); + else + p = NULL; + spin_unlock(&nfs_referral_count_list_lock); + kfree(p); +} + +static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt, + const char *export_path) +{ + struct dentry *dentry; + int err; + + if (IS_ERR(root_mnt)) + return ERR_CAST(root_mnt); + + err = nfs_referral_loop_protect(); + if (err) { + mntput(root_mnt); + return ERR_PTR(err); + } + + dentry = mount_subtree(root_mnt, export_path); + nfs_referral_loop_unprotect(); + + return dentry; +} + +static struct dentry *nfs4_try_mount(int flags, const char *dev_name, + struct nfs_parsed_mount_data *data) +{ + char *export_path; + struct vfsmount *root_mnt; + struct dentry *res; + + dfprintk(MOUNT, "--> nfs4_try_mount()\n"); + + export_path = data->nfs_server.export_path; + data->nfs_server.export_path = "/"; + root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data, + data->nfs_server.hostname); + data->nfs_server.export_path = export_path; + + res = nfs_follow_remote_path(root_mnt, export_path); + + dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n", + IS_ERR(res) ? PTR_ERR(res) : 0, + IS_ERR(res) ? " [error]" : ""); + return res; +} + +/* + * Get the superblock for an NFS4 mountpoint + */ +static struct dentry *nfs4_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data) +{ + struct nfs_parsed_mount_data *data; + int error = -ENOMEM; + struct dentry *res = ERR_PTR(-ENOMEM); + + data = nfs_alloc_parsed_mount_data(4); + if (data == NULL) + goto out; + + /* Validate the mount data */ + error = nfs4_validate_mount_data(raw_data, data, dev_name); + if (error < 0) { + res = ERR_PTR(error); + goto out; + } + + res = nfs4_try_mount(flags, dev_name, data); + if (IS_ERR(res)) + error = PTR_ERR(res); + +out: + nfs_free_parsed_mount_data(data); + dprintk("<-- nfs4_mount() = %d%s\n", error, + error != 0 ? " [error]" : ""); + return res; +} + +static void nfs4_kill_super(struct super_block *sb) +{ + struct nfs_server *server = NFS_SB(sb); + + dprintk("--> %s\n", __func__); + nfs_super_return_all_delegations(sb); + kill_anon_super(sb); + nfs_fscache_release_super_cookie(sb); + nfs_free_server(server); + dprintk("<-- %s\n", __func__); +} + +/* + * Clone an NFS4 server record on xdev traversal (FSID-change) + */ +static struct dentry * +nfs4_xdev_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data) +{ + struct nfs_clone_mount *data = raw_data; + struct super_block *s; + struct nfs_server *server; + struct dentry *mntroot; + int (*compare_super)(struct super_block *, void *) = nfs_compare_super; + struct nfs_sb_mountdata sb_mntdata = { + .mntflags = flags, + }; + int error; + + dprintk("--> nfs4_xdev_mount()\n"); + + /* create a new volume representation */ + server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor); + if (IS_ERR(server)) { + error = PTR_ERR(server); + goto out_err_noserver; + } + sb_mntdata.server = server; + + if (server->flags & NFS4_MOUNT_UNSHARED) + compare_super = NULL; + + /* -o noac implies -o sync */ + if (server->flags & NFS_MOUNT_NOAC) + sb_mntdata.mntflags |= MS_SYNCHRONOUS; + + /* Get a superblock - note that we may end up sharing one that already exists */ + s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata); + if (IS_ERR(s)) { + error = PTR_ERR(s); + goto out_err_nosb; + } + + if (s->s_fs_info != server) { + nfs_free_server(server); + server = NULL; + } else { + error = nfs_bdi_register(server); + if (error) + goto error_splat_bdi; + } + + if (!s->s_root) { + /* initial superblock/root creation */ + nfs4_clone_super(s, data->sb); + nfs_fscache_get_super_cookie(s, NULL, data); + } + + mntroot = nfs4_get_root(s, data->fh, dev_name); + if (IS_ERR(mntroot)) { + error = PTR_ERR(mntroot); + goto error_splat_super; + } + if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) { + dput(mntroot); + error = -ESTALE; + goto error_splat_super; + } + + s->s_flags |= MS_ACTIVE; + + security_sb_clone_mnt_opts(data->sb, s); + + dprintk("<-- nfs4_xdev_mount() = 0\n"); + return mntroot; + +out_err_nosb: + nfs_free_server(server); +out_err_noserver: + dprintk("<-- nfs4_xdev_mount() = %d [error]\n", error); + return ERR_PTR(error); + +error_splat_super: + if (server && !s->s_root) + bdi_unregister(&server->backing_dev_info); +error_splat_bdi: + deactivate_locked_super(s); + dprintk("<-- nfs4_xdev_mount() = %d [splat]\n", error); + return ERR_PTR(error); +} + +static struct dentry * +nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data) +{ + struct nfs_clone_mount *data = raw_data; + struct super_block *s; + struct nfs_server *server; + struct dentry *mntroot; + struct nfs_fh *mntfh; + int (*compare_super)(struct super_block *, void *) = nfs_compare_super; + struct nfs_sb_mountdata sb_mntdata = { + .mntflags = flags, + }; + int error = -ENOMEM; + + dprintk("--> nfs4_referral_get_sb()\n"); + + mntfh = nfs_alloc_fhandle(); + if (mntfh == NULL) + goto out_err_nofh; + + /* create a new volume representation */ + server = nfs4_create_referral_server(data, mntfh); + if (IS_ERR(server)) { + error = PTR_ERR(server); + goto out_err_noserver; + } + sb_mntdata.server = server; + + if (server->flags & NFS4_MOUNT_UNSHARED) + compare_super = NULL; + + /* -o noac implies -o sync */ + if (server->flags & NFS_MOUNT_NOAC) + sb_mntdata.mntflags |= MS_SYNCHRONOUS; + + /* Get a superblock - note that we may end up sharing one that already exists */ + s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata); + if (IS_ERR(s)) { + error = PTR_ERR(s); + goto out_err_nosb; + } + + if (s->s_fs_info != server) { + nfs_free_server(server); + server = NULL; + } else { + error = nfs_bdi_register(server); + if (error) + goto error_splat_bdi; + } + + if (!s->s_root) { + /* initial superblock/root creation */ + nfs4_fill_super(s); + nfs_fscache_get_super_cookie(s, NULL, data); + } + + mntroot = nfs4_get_root(s, mntfh, dev_name); + if (IS_ERR(mntroot)) { + error = PTR_ERR(mntroot); + goto error_splat_super; + } + if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) { + dput(mntroot); + error = -ESTALE; + goto error_splat_super; + } + + s->s_flags |= MS_ACTIVE; + + security_sb_clone_mnt_opts(data->sb, s); + + nfs_free_fhandle(mntfh); + dprintk("<-- nfs4_referral_get_sb() = 0\n"); + return mntroot; + +out_err_nosb: + nfs_free_server(server); +out_err_noserver: + nfs_free_fhandle(mntfh); +out_err_nofh: + dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error); + return ERR_PTR(error); + +error_splat_super: + if (server && !s->s_root) + bdi_unregister(&server->backing_dev_info); +error_splat_bdi: + deactivate_locked_super(s); + nfs_free_fhandle(mntfh); + dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error); + return ERR_PTR(error); +} + +/* + * Create an NFS4 server record on referral traversal + */ +static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data) +{ + struct nfs_clone_mount *data = raw_data; + char *export_path; + struct vfsmount *root_mnt; + struct dentry *res; + + dprintk("--> nfs4_referral_mount()\n"); + + export_path = data->mnt_path; + data->mnt_path = "/"; + + root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type, + flags, data, data->hostname); + data->mnt_path = export_path; + + res = nfs_follow_remote_path(root_mnt, export_path); + dprintk("<-- nfs4_referral_mount() = %ld%s\n", + IS_ERR(res) ? PTR_ERR(res) : 0, + IS_ERR(res) ? " [error]" : ""); + return res; +} + +#endif /* CONFIG_NFS_V4 */ -- cgit