// SPDX-License-Identifier: GPL-2.0-only /* * linux/fs/nfs/super.c * * Copyright (C) 1992 Rick Sladkey * * nfs superblock handling functions * * Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, 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 <dhowells@redhat.com> * * - 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 <linux/module.h> #include <linux/init.h> #include <linux/time.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/string.h> #include <linux/stat.h> #include <linux/errno.h> #include <linux/unistd.h> #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/addr.h> #include <linux/sunrpc/stats.h> #include <linux/sunrpc/metrics.h> #include <linux/sunrpc/xprtsock.h> #include <linux/sunrpc/xprtrdma.h> #include <linux/nfs_fs.h> #include <linux/nfs_mount.h> #include <linux/nfs4_mount.h> #include <linux/lockd/bind.h> #include <linux/seq_file.h> #include <linux/mount.h> #include <linux/namei.h> #include <linux/vfs.h> #include <linux/inet.h> #include <linux/in6.h> #include <linux/slab.h> #include <net/ipv6.h> #include <linux/netdevice.h> #include <linux/nfs_xdr.h> #include <linux/magic.h> #include <linux/parser.h> #include <linux/nsproxy.h> #include <linux/rcupdate.h> #include <linux/uaccess.h> #include <linux/nfs_ssc.h> #include "nfs4_fs.h" #include "callback.h" #include "delegation.h" #include "iostat.h" #include "internal.h" #include "fscache.h" #include "nfs4session.h" #include "pnfs.h" #include "nfs.h" #define NFSDBG_FACILITY NFSDBG_VFS const struct super_operations nfs_sops = { .alloc_inode = nfs_alloc_inode, .free_inode = nfs_free_inode, .write_inode = nfs_write_inode, .drop_inode = nfs_drop_inode, .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, }; EXPORT_SYMBOL_GPL(nfs_sops); #ifdef CONFIG_NFS_V4_2 static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = { .sco_sb_deactive = nfs_sb_deactive, }; #endif #if IS_ENABLED(CONFIG_NFS_V4) static int __init register_nfs4_fs(void) { return register_filesystem(&nfs4_fs_type); } static void unregister_nfs4_fs(void) { unregister_filesystem(&nfs4_fs_type); } #else static int __init register_nfs4_fs(void) { return 0; } static void unregister_nfs4_fs(void) { } #endif #ifdef CONFIG_NFS_V4_2 static void nfs_ssc_register_ops(void) { nfs_ssc_register(&nfs_ssc_clnt_ops_tbl); } static void nfs_ssc_unregister_ops(void) { nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl); } #endif /* CONFIG_NFS_V4_2 */ static struct shrinker acl_shrinker = { .count_objects = nfs_access_cache_count, .scan_objects = nfs_access_cache_scan, .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 = register_nfs4_fs(); if (ret < 0) goto error_1; ret = nfs_register_sysctl(); if (ret < 0) goto error_2; ret = register_shrinker(&acl_shrinker); if (ret < 0) goto error_3; #ifdef CONFIG_NFS_V4_2 nfs_ssc_register_ops(); #endif return 0; error_3: nfs_unregister_sysctl(); error_2: unregister_nfs4_fs(); 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); nfs_unregister_sysctl(); unregister_nfs4_fs(); #ifdef CONFIG_NFS_V4_2 nfs_ssc_unregister_ops(); #endif unregister_filesystem(&nfs_fs_type); } bool nfs_sb_active(struct super_block *sb) { struct nfs_server *server = NFS_SB(sb); if (!atomic_inc_not_zero(&sb->s_active)) return false; if (atomic_inc_return(&server->active) != 1) atomic_dec(&sb->s_active); return true; } EXPORT_SYMBOL_GPL(nfs_sb_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); } EXPORT_SYMBOL_GPL(nfs_sb_deactive); static int __nfs_list_for_each_server(struct list_head *head, int (*fn)(struct nfs_server *, void *), void *data) { struct nfs_server *server, *last = NULL; int ret = 0; rcu_read_lock(); list_for_each_entry_rcu(server, head, client_link) { if (!(server->super && nfs_sb_active(server->super))) continue; rcu_read_unlock(); if (last) nfs_sb_deactive(last->super); last = server; ret = fn(server, data); if (ret) goto out; rcu_read_lock(); } rcu_read_unlock(); out: if (last) nfs_sb_deactive(last->super); return ret; } int nfs_client_for_each_server(struct nfs_client *clp, int (*fn)(struct nfs_server *, void *), void *data) { return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data); } EXPORT_SYMBOL_GPL(nfs_client_for_each_server); /* * Deliver file system statistics to userspace */ 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(d_inode(dentry)); 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); nfs_zap_caches(d_inode(pd_dentry)); 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; } EXPORT_SYMBOL_GPL(nfs_statfs); /* * 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[NFS_AUTH_INFO_MAX_FLAVORS] = { /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */ { 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; char *proto = NULL; switch (sap->sa_family) { case AF_INET: switch (nfss->mountd_protocol) { case IPPROTO_UDP: proto = RPCBIND_NETID_UDP; break; case IPPROTO_TCP: proto = RPCBIND_NETID_TCP; break; } break; case AF_INET6: switch (nfss->mountd_protocol) { case IPPROTO_UDP: proto = RPCBIND_NETID_UDP6; break; case IPPROTO_TCP: proto = RPCBIND_NETID_TCP6; break; } break; } if (proto || showdefaults) seq_printf(m, ",mountproto=%s", proto ?: "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_puts(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); } #if IS_ENABLED(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", "" }, { NFS_MOUNT_SOFTERR, ",softerr", "" }, { NFS_MOUNT_SOFTREVAL, ",softreval", "" }, { 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); if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))) seq_puts(m, ",hard"); 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 (clp->cl_nconnect > 0) seq_printf(m, ",nconnect=%u", clp->cl_nconnect); if (version == 4) { if (clp->cl_max_connect > 1) seq_printf(m, ",max_connect=%u", clp->cl_max_connect); 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_puts(m, ",fsc"); if (nfss->options & NFS_OPTION_MIGRATION) seq_puts(m, ",migration"); if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) { if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) seq_puts(m, ",lookupcache=none"); else seq_puts(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_puts(m, ",local_lock=none"); else if (local_flock && local_fcntl) seq_puts(m, ",local_lock=all"); else if (local_flock) seq_puts(m, ",local_lock=flock"); else seq_puts(m, ",local_lock=posix"); if (nfss->flags & NFS_MOUNT_WRITE_EAGER) { if (nfss->flags & NFS_MOUNT_WRITE_WAIT) seq_puts(m, ",write=wait"); else seq_puts(m, ",write=eager"); } } /* * Describe the mount options on this VFS mountpoint */ 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; } EXPORT_SYMBOL_GPL(nfs_show_options); #if IS_ENABLED(CONFIG_NFS_V4) static void show_lease(struct seq_file *m, struct nfs_server *server) { struct nfs_client *clp = server->nfs_client; unsigned long expire; seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ); expire = clp->cl_last_renewal + clp->cl_lease_time; seq_printf(m, ",lease_expired=%ld", time_after(expire, jiffies) ? 0 : (jiffies - expire) / HZ); } #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_puts(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->cl_implid) { struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid; 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 #if IS_ENABLED(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 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, 0); if (IS_ERR(devname)) err = PTR_ERR(devname); else seq_escape(m, devname, " \t\n\\"); free_page((unsigned long)page); return err; } EXPORT_SYMBOL_GPL(nfs_show_devname); int nfs_show_path(struct seq_file *m, struct dentry *dentry) { seq_puts(m, "/"); return 0; } EXPORT_SYMBOL_GPL(nfs_show_path); /* * Present statistical information for this VFS mountpoint */ 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_puts(m, "\n\topts:\t"); seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw"); seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : ""); seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : ""); seq_puts(m, root->d_sb->s_flags & SB_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_puts(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); #if IS_ENABLED(CONFIG_NFS_V4) if (nfss->nfs_client->rpc_ops->version == 4) { seq_puts(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, ",bm2=0x%x", nfss->attr_bitmask[2]); seq_printf(m, ",acl=0x%x", nfss->acl_bitmask); show_sessions(m, nfss); show_pnfs(m, nfss); show_lease(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_puts(m, "\n\tevents:\t"); for (i = 0; i < __NFSIOS_COUNTSMAX; i++) seq_printf(m, "%lu ", totals.events[i]); seq_puts(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_puts(m, "\n\tfsc:\t"); for (i = 0; i < __NFSIOS_FSCACHEMAX; i++) seq_printf(m, "%Lu ", totals.fscache[i]); } #endif seq_putc(m, '\n'); rpc_clnt_show_stats(m, nfss->client); return 0; } EXPORT_SYMBOL_GPL(nfs_show_stats); /* * Begin unmount by attempting to remove all automounted mountpoints we added * in response to xdev traversals and referrals */ 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); } EXPORT_SYMBOL_GPL(nfs_umount_begin); /* * Return true if 'match' is in auth_info or auth_info is empty. * Return false otherwise. */ bool nfs_auth_info_match(const struct nfs_auth_info *auth_info, rpc_authflavor_t match) { int i; if (!auth_info->flavor_len) return true; for (i = 0; i < auth_info->flavor_len; i++) { if (auth_info->flavors[i] == match) return true; } return false; } EXPORT_SYMBOL_GPL(nfs_auth_info_match); /* * Ensure that a specified authtype in ctx->auth_info is supported by * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and * -EACCES if not. */ static int nfs_verify_authflavors(struct nfs_fs_context *ctx, rpc_authflavor_t *server_authlist, unsigned int count) { rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR; bool found_auth_null = false; unsigned int i; /* * If the sec= mount option is used, the specified flavor or AUTH_NULL * must be in the list returned by the server. * * AUTH_NULL has a special meaning when it's in the server list - it * means that the server will ignore the rpc creds, so any flavor * can be used but still use the sec= that was specified. * * Note also that the MNT procedure in MNTv1 does not return a list * of supported security flavors. In this case, nfs_mount() fabricates * a security flavor list containing just AUTH_NULL. */ for (i = 0; i < count; i++) { flavor = server_authlist[i]; if (nfs_auth_info_match(&ctx->auth_info, flavor)) goto out; if (flavor == RPC_AUTH_NULL) found_auth_null = true; } if (found_auth_null) { flavor = ctx->auth_info.flavors[0]; goto out; } dfprintk(MOUNT, "NFS: specified auth flavors not supported by server\n"); return -EACCES; out: ctx->selected_flavor = flavor; dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor); return 0; } /* * Use the remote server's MOUNT service to request the NFS file handle * corresponding to the provided path. */ static int nfs_request_mount(struct fs_context *fc, struct nfs_fh *root_fh, rpc_authflavor_t *server_authlist, unsigned int *server_authlist_len) { struct nfs_fs_context *ctx = nfs_fc2context(fc); struct nfs_mount_request request = { .sap = (struct sockaddr *) &ctx->mount_server.address, .dirpath = ctx->nfs_server.export_path, .protocol = ctx->mount_server.protocol, .fh = root_fh, .noresvport = ctx->flags & NFS_MOUNT_NORESVPORT, .auth_flav_len = server_authlist_len, .auth_flavs = server_authlist, .net = fc->net_ns, }; int status; if (ctx->mount_server.version == 0) { switch (ctx->version) { default: ctx->mount_server.version = NFS_MNT3_VERSION; break; case 2: ctx->mount_server.version = NFS_MNT_VERSION; } } request.version = ctx->mount_server.version; if (ctx->mount_server.hostname) request.hostname = ctx->mount_server.hostname; else request.hostname = ctx->nfs_server.hostname; /* * Construct the mount server's address. */ if (ctx->mount_server.address.sa_family == AF_UNSPEC) { memcpy(request.sap, &ctx->nfs_server.address, ctx->nfs_server.addrlen); ctx->mount_server.addrlen = ctx->nfs_server.addrlen; } request.salen = ctx->mount_server.addrlen; nfs_set_port(request.sap, &ctx->mount_server.port, 0); /* * Now ask the mount server to map our export path * to a file handle. */ status = nfs_mount(&request, ctx->timeo, ctx->retrans); if (status != 0) { dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n", request.hostname, status); return status; } return 0; } static struct nfs_server *nfs_try_mount_request(struct fs_context *fc) { struct nfs_fs_context *ctx = nfs_fc2context(fc); int status; unsigned int i; bool tried_auth_unix = false; bool auth_null_in_list = false; struct nfs_server *server = ERR_PTR(-EACCES); rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS]; unsigned int authlist_len = ARRAY_SIZE(authlist); status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len); if (status) return ERR_PTR(status); /* * Was a sec= authflavor specified in the options? First, verify * whether the server supports it, and then just try to use it if so. */ if (ctx->auth_info.flavor_len > 0) { status = nfs_verify_authflavors(ctx, authlist, authlist_len); dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor); if (status) return ERR_PTR(status); return ctx->nfs_mod->rpc_ops->create_server(fc); } /* * No sec= option was provided. RFC 2623, section 2.7 suggests we * SHOULD prefer the flavor listed first. However, some servers list * AUTH_NULL first. Avoid ever choosing AUTH_NULL. */ for (i = 0; i < authlist_len; ++i) { rpc_authflavor_t flavor; struct rpcsec_gss_info info; flavor = authlist[i]; switch (flavor) { case RPC_AUTH_UNIX: tried_auth_unix = true; break; case RPC_AUTH_NULL: auth_null_in_list = true; continue; default: if (rpcauth_get_gssinfo(flavor, &info) != 0) continue; break; } dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor); ctx->selected_flavor = flavor; server = ctx->nfs_mod->rpc_ops->create_server(fc); if (!IS_ERR(server)) return server; } /* * Nothing we tried so far worked. At this point, give up if we've * already tried AUTH_UNIX or if the server's list doesn't contain * AUTH_NULL */ if (tried_auth_unix || !auth_null_in_list) return server; /* Last chance! Try AUTH_UNIX */ dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX); ctx->selected_flavor = RPC_AUTH_UNIX; return ctx->nfs_mod->rpc_ops->create_server(fc); } int nfs_try_get_tree(struct fs_context *fc) { struct nfs_fs_context *ctx = nfs_fc2context(fc); if (ctx->need_mount) ctx->server = nfs_try_mount_request(fc); else ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc); return nfs_get_tree_common(fc); } EXPORT_SYMBOL_GPL(nfs_try_get_tree); #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \ | NFS_MOUNT_SECURE \ | NFS_MOUNT_TCP \ | NFS_MOUNT_VER3 \ | NFS_MOUNT_KERBEROS \ | NFS_MOUNT_NONLM \ | NFS_MOUNT_BROKEN_SUID \ | NFS_MOUNT_STRICTLOCK \ | NFS_MOUNT_LEGACY_INTERFACE) #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \ ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT)) static int nfs_compare_remount_data(struct nfs_server *nfss, struct nfs_fs_context *ctx) { if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK || ctx->rsize != nfss->rsize || ctx->wsize != nfss->wsize || ctx->version != nfss->nfs_client->rpc_ops->version || ctx->minorversion != nfss->nfs_client->cl_minorversion || ctx->retrans != nfss->client->cl_timeout->to_retries || !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) || ctx->acregmin != nfss->acregmin / HZ || ctx->acregmax != nfss->acregmax / HZ || ctx->acdirmin != nfss->acdirmin / HZ || ctx->acdirmax != nfss->acdirmax / HZ || ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) || (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) || ctx->nfs_server.port != nfss->port || ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen || !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address, (struct sockaddr *)&nfss->nfs_client->cl_addr)) return -EINVAL; return 0; } int nfs_reconfigure(struct fs_context *fc) { struct nfs_fs_context *ctx = nfs_fc2context(fc); struct super_block *sb = fc->root->d_sb; struct nfs_server *nfss = sb->s_fs_info; int ret; sync_filesystem(sb); /* * 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 (ctx->skip_reconfig_option_check) return 0; /* * noac is a special case. It implies -o sync, but that's not * necessarily reflected in the mtab options. reconfigure_super * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the * remount options, so we have to explicitly reset it. */ if (ctx->flags & NFS_MOUNT_NOAC) { fc->sb_flags |= SB_SYNCHRONOUS; fc->sb_flags_mask |= SB_SYNCHRONOUS; } /* compare new mount options with old ones */ ret = nfs_compare_remount_data(nfss, ctx); if (ret) return ret; return nfs_probe_server(nfss, NFS_FH(d_inode(fc->root))); } EXPORT_SYMBOL_GPL(nfs_reconfigure); /* * Finish setting up an NFS superblock */ static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx) { struct nfs_server *server = NFS_SB(sb); sb->s_blocksize_bits = 0; sb->s_blocksize = 0; sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr; sb->s_op = server->nfs_client->cl_nfs_mod->sops; if (ctx->bsize) sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits); if (server->nfs_client->rpc_ops->version != 2) { /* The VFS shouldn't apply the umask to mode bits. We will do * so ourselves when necessary. */ sb->s_flags |= SB_POSIXACL; sb->s_time_gran = 1; sb->s_export_op = &nfs_export_ops; } else sb->s_time_gran = 1000; if (server->nfs_client->rpc_ops->version != 4) { sb->s_time_min = 0; sb->s_time_max = U32_MAX; } else { sb->s_time_min = S64_MIN; sb->s_time_max = S64_MAX; } 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); nfs_super_set_maxbytes(sb, server->maxfilesize); server->has_sec_mnt_opts = ctx->has_sec_mnt_opts; } static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, const struct fs_context *fc) { 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_SB_MASK) != (fc->sb_flags & NFS_SB_MASK)) goto Ebusy; if (a->nfs_client != b->nfs_client) goto Ebusy; if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK) 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; } static int nfs_set_super(struct super_block *s, struct fs_context *fc) { struct nfs_server *server = fc->s_fs_info; int ret; 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; struct rpc_xprt *xprt1 = server1->client->cl_xprt; struct rpc_xprt *xprt2 = server2->client->cl_xprt; if (!net_eq(xprt1->xprt_net, xprt2->xprt_net)) return 0; 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_userns(const struct nfs_server *old, const struct nfs_server *new) { const struct user_namespace *oldns = &init_user_ns; const struct user_namespace *newns = &init_user_ns; if (old->client && old->client->cl_cred) oldns = old->client->cl_cred->user_ns; if (new->client && new->client->cl_cred) newns = new->client->cl_cred->user_ns; if (oldns != newns) return 0; return 1; } static int nfs_compare_super(struct super_block *sb, struct fs_context *fc) { struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb); 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; if (!nfs_compare_userns(old, server)) return 0; if ((old->has_sec_mnt_opts || fc->security) && security_sb_mnt_opts_compat(sb, fc->security)) return 0; return nfs_compare_mount_options(sb, server, fc); } #ifdef CONFIG_NFS_FSCACHE static void nfs_get_cache_cookie(struct super_block *sb, struct nfs_fs_context *ctx) { struct nfs_server *nfss = NFS_SB(sb); char *uniq = NULL; int ulen = 0; nfss->fscache_key = NULL; nfss->fscache = NULL; if (!ctx) return; if (ctx->clone_data.sb) { struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb); if (!(mnt_s->options & NFS_OPTION_FSCACHE)) return; if (mnt_s->fscache_key) { uniq = mnt_s->fscache_key->key.uniquifier; ulen = mnt_s->fscache_key->key.uniq_len; } } else { if (!(ctx->options & NFS_OPTION_FSCACHE)) return; if (ctx->fscache_uniq) { uniq = ctx->fscache_uniq; ulen = strlen(ctx->fscache_uniq); } } nfs_fscache_get_super_cookie(sb, uniq, ulen); } #else static void nfs_get_cache_cookie(struct super_block *sb, struct nfs_fs_context *ctx) { } #endif int nfs_get_tree_common(struct fs_context *fc) { struct nfs_fs_context *ctx = nfs_fc2context(fc); struct super_block *s; int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super; struct nfs_server *server = ctx->server; int error; ctx->server = NULL; if (IS_ERR(server)) return PTR_ERR(server); if (server->flags & NFS_MOUNT_UNSHARED) compare_super = NULL; /* -o noac implies -o sync */ if (server->flags & NFS_MOUNT_NOAC) fc->sb_flags |= SB_SYNCHRONOUS; if (ctx->clone_data.sb) if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS) fc->sb_flags |= SB_SYNCHRONOUS; if (server->caps & NFS_CAP_SECURITY_LABEL) fc->lsm_flags |= SECURITY_LSM_NATIVE_LABELS; /* Get a superblock - note that we may end up sharing one that already exists */ fc->s_fs_info = server; s = sget_fc(fc, compare_super, nfs_set_super); fc->s_fs_info = NULL; if (IS_ERR(s)) { error = PTR_ERR(s); nfs_errorf(fc, "NFS: Couldn't get superblock"); goto out_err_nosb; } if (s->s_fs_info != server) { nfs_free_server(server); server = NULL; } else { error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev), MINOR(server->s_dev)); if (error) goto error_splat_super; s->s_bdi->io_pages = server->rpages; server->super = s; } if (!s->s_root) { unsigned bsize = ctx->clone_data.inherited_bsize; /* initial superblock/root creation */ nfs_fill_super(s, ctx); if (bsize) { s->s_blocksize_bits = bsize; s->s_blocksize = 1U << bsize; } nfs_get_cache_cookie(s, ctx); } error = nfs_get_root(s, fc); if (error < 0) { nfs_errorf(fc, "NFS: Couldn't get root dentry"); goto error_splat_super; } s->s_flags |= SB_ACTIVE; error = 0; out: return error; out_err_nosb: nfs_free_server(server); goto out; error_splat_super: deactivate_locked_super(s); goto out; } /* * Destroy an NFS2/3 superblock */ void nfs_kill_super(struct super_block *s) { struct nfs_server *server = NFS_SB(s); dev_t dev = s->s_dev; generic_shutdown_super(s); nfs_fscache_release_super_cookie(s); nfs_free_server(server); free_anon_bdev(dev); } EXPORT_SYMBOL_GPL(nfs_kill_super); #if IS_ENABLED(CONFIG_NFS_V4) /* * NFS v4 module parameters need to stay in the * NFS client for backwards compatibility */ unsigned int nfs_callback_set_tcpport; unsigned short nfs_callback_nr_threads; /* Default cache timeout is 10 minutes */ unsigned int nfs_idmap_cache_timeout = 600; /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */ bool nfs4_disable_idmapping = true; unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE; unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE; unsigned short send_implementation_id = 1; char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = ""; bool recover_lost_locks = false; EXPORT_SYMBOL_GPL(nfs_callback_nr_threads); EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport); EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout); EXPORT_SYMBOL_GPL(nfs4_disable_idmapping); EXPORT_SYMBOL_GPL(max_session_slots); EXPORT_SYMBOL_GPL(max_session_cb_slots); EXPORT_SYMBOL_GPL(send_implementation_id); EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier); EXPORT_SYMBOL_GPL(recover_lost_locks); #define NFS_CALLBACK_MAXPORTNR (65535U) static int param_set_portnr(const char *val, const struct kernel_param *kp) { unsigned long num; int ret; if (!val) return -EINVAL; ret = kstrtoul(val, 0, &num); if (ret || num > NFS_CALLBACK_MAXPORTNR) return -EINVAL; *((unsigned int *)kp->arg) = num; return 0; } static const struct kernel_param_ops param_ops_portnr = { .set = param_set_portnr, .get = param_get_uint, }; #define param_check_portnr(name, p) __param_check(name, p, unsigned int) module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644); module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644); MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be " "assigned to the NFSv4 callback channels."); 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); MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 " "requests the client will negotiate"); module_param(max_session_cb_slots, ushort, 0644); MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 " "callbacks the client will process for a given server"); 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_param(recover_lost_locks, bool, 0644); MODULE_PARM_DESC(recover_lost_locks, "If the server reports that a lock might be lost, " "try to recover it risking data corruption."); #endif /* CONFIG_NFS_V4 */