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-rw-r--r--fs/nfsd/nfssvc.c663
1 files changed, 663 insertions, 0 deletions
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
new file mode 100644
index 00000000000..eda7d7e55e0
--- /dev/null
+++ b/fs/nfsd/nfssvc.c
@@ -0,0 +1,663 @@
+/*
+ * Central processing for nfsd.
+ *
+ * Authors: Olaf Kirch (okir@monad.swb.de)
+ *
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/sched.h>
+#include <linux/freezer.h>
+#include <linux/module.h>
+#include <linux/fs_struct.h>
+#include <linux/swap.h>
+
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/lockd/bind.h>
+#include <linux/nfsacl.h>
+#include <linux/seq_file.h>
+#include <net/net_namespace.h>
+#include "nfsd.h"
+#include "cache.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY NFSDDBG_SVC
+
+extern struct svc_program nfsd_program;
+static int nfsd(void *vrqstp);
+struct timeval nfssvc_boot;
+
+/*
+ * nfsd_mutex protects nfsd_serv -- both the pointer itself and the members
+ * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
+ * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
+ *
+ * If (out side the lock) nfsd_serv is non-NULL, then it must point to a
+ * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
+ * of nfsd threads must exist and each must listed in ->sp_all_threads in each
+ * entry of ->sv_pools[].
+ *
+ * Transitions of the thread count between zero and non-zero are of particular
+ * interest since the svc_serv needs to be created and initialized at that
+ * point, or freed.
+ *
+ * Finally, the nfsd_mutex also protects some of the global variables that are
+ * accessed when nfsd starts and that are settable via the write_* routines in
+ * nfsctl.c. In particular:
+ *
+ * user_recovery_dirname
+ * user_lease_time
+ * nfsd_versions
+ */
+DEFINE_MUTEX(nfsd_mutex);
+struct svc_serv *nfsd_serv;
+
+/*
+ * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
+ * nfsd_drc_max_pages limits the total amount of memory available for
+ * version 4.1 DRC caches.
+ * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
+ */
+spinlock_t nfsd_drc_lock;
+unsigned int nfsd_drc_max_mem;
+unsigned int nfsd_drc_mem_used;
+
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+static struct svc_stat nfsd_acl_svcstats;
+static struct svc_version * nfsd_acl_version[] = {
+ [2] = &nfsd_acl_version2,
+ [3] = &nfsd_acl_version3,
+};
+
+#define NFSD_ACL_MINVERS 2
+#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
+static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
+
+static struct svc_program nfsd_acl_program = {
+ .pg_prog = NFS_ACL_PROGRAM,
+ .pg_nvers = NFSD_ACL_NRVERS,
+ .pg_vers = nfsd_acl_versions,
+ .pg_name = "nfsacl",
+ .pg_class = "nfsd",
+ .pg_stats = &nfsd_acl_svcstats,
+ .pg_authenticate = &svc_set_client,
+};
+
+static struct svc_stat nfsd_acl_svcstats = {
+ .program = &nfsd_acl_program,
+};
+#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
+
+static struct svc_version * nfsd_version[] = {
+ [2] = &nfsd_version2,
+#if defined(CONFIG_NFSD_V3)
+ [3] = &nfsd_version3,
+#endif
+#if defined(CONFIG_NFSD_V4)
+ [4] = &nfsd_version4,
+#endif
+};
+
+#define NFSD_MINVERS 2
+#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
+static struct svc_version *nfsd_versions[NFSD_NRVERS];
+
+struct svc_program nfsd_program = {
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+ .pg_next = &nfsd_acl_program,
+#endif
+ .pg_prog = NFS_PROGRAM, /* program number */
+ .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
+ .pg_vers = nfsd_versions, /* version table */
+ .pg_name = "nfsd", /* program name */
+ .pg_class = "nfsd", /* authentication class */
+ .pg_stats = &nfsd_svcstats, /* version table */
+ .pg_authenticate = &svc_set_client, /* export authentication */
+
+};
+
+u32 nfsd_supported_minorversion;
+
+int nfsd_vers(int vers, enum vers_op change)
+{
+ if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
+ return 0;
+ switch(change) {
+ case NFSD_SET:
+ nfsd_versions[vers] = nfsd_version[vers];
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+ if (vers < NFSD_ACL_NRVERS)
+ nfsd_acl_versions[vers] = nfsd_acl_version[vers];
+#endif
+ break;
+ case NFSD_CLEAR:
+ nfsd_versions[vers] = NULL;
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+ if (vers < NFSD_ACL_NRVERS)
+ nfsd_acl_versions[vers] = NULL;
+#endif
+ break;
+ case NFSD_TEST:
+ return nfsd_versions[vers] != NULL;
+ case NFSD_AVAIL:
+ return nfsd_version[vers] != NULL;
+ }
+ return 0;
+}
+
+int nfsd_minorversion(u32 minorversion, enum vers_op change)
+{
+ if (minorversion > NFSD_SUPPORTED_MINOR_VERSION)
+ return -1;
+ switch(change) {
+ case NFSD_SET:
+ nfsd_supported_minorversion = minorversion;
+ break;
+ case NFSD_CLEAR:
+ if (minorversion == 0)
+ return -1;
+ nfsd_supported_minorversion = minorversion - 1;
+ break;
+ case NFSD_TEST:
+ return minorversion <= nfsd_supported_minorversion;
+ case NFSD_AVAIL:
+ return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
+ }
+ return 0;
+}
+
+/*
+ * Maximum number of nfsd processes
+ */
+#define NFSD_MAXSERVS 8192
+
+int nfsd_nrthreads(void)
+{
+ int rv = 0;
+ mutex_lock(&nfsd_mutex);
+ if (nfsd_serv)
+ rv = nfsd_serv->sv_nrthreads;
+ mutex_unlock(&nfsd_mutex);
+ return rv;
+}
+
+static int nfsd_init_socks(int port)
+{
+ int error;
+ if (!list_empty(&nfsd_serv->sv_permsocks))
+ return 0;
+
+ error = svc_create_xprt(nfsd_serv, "udp", &init_net, PF_INET, port,
+ SVC_SOCK_DEFAULTS);
+ if (error < 0)
+ return error;
+
+ error = svc_create_xprt(nfsd_serv, "tcp", &init_net, PF_INET, port,
+ SVC_SOCK_DEFAULTS);
+ if (error < 0)
+ return error;
+
+ return 0;
+}
+
+static bool nfsd_up = false;
+
+static int nfsd_startup(unsigned short port, int nrservs)
+{
+ int ret;
+
+ if (nfsd_up)
+ return 0;
+ /*
+ * Readahead param cache - will no-op if it already exists.
+ * (Note therefore results will be suboptimal if number of
+ * threads is modified after nfsd start.)
+ */
+ ret = nfsd_racache_init(2*nrservs);
+ if (ret)
+ return ret;
+ ret = nfsd_init_socks(port);
+ if (ret)
+ goto out_racache;
+ ret = lockd_up();
+ if (ret)
+ goto out_racache;
+ ret = nfs4_state_start();
+ if (ret)
+ goto out_lockd;
+ nfsd_up = true;
+ return 0;
+out_lockd:
+ lockd_down();
+out_racache:
+ nfsd_racache_shutdown();
+ return ret;
+}
+
+static void nfsd_shutdown(void)
+{
+ /*
+ * write_ports can create the server without actually starting
+ * any threads--if we get shut down before any threads are
+ * started, then nfsd_last_thread will be run before any of this
+ * other initialization has been done.
+ */
+ if (!nfsd_up)
+ return;
+ nfs4_state_shutdown();
+ lockd_down();
+ nfsd_racache_shutdown();
+ nfsd_up = false;
+}
+
+static void nfsd_last_thread(struct svc_serv *serv)
+{
+ /* When last nfsd thread exits we need to do some clean-up */
+ nfsd_serv = NULL;
+ nfsd_shutdown();
+
+ svc_rpcb_cleanup(serv);
+
+ printk(KERN_WARNING "nfsd: last server has exited, flushing export "
+ "cache\n");
+ nfsd_export_flush();
+}
+
+void nfsd_reset_versions(void)
+{
+ int found_one = 0;
+ int i;
+
+ for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
+ if (nfsd_program.pg_vers[i])
+ found_one = 1;
+ }
+
+ if (!found_one) {
+ for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
+ nfsd_program.pg_vers[i] = nfsd_version[i];
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+ for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
+ nfsd_acl_program.pg_vers[i] =
+ nfsd_acl_version[i];
+#endif
+ }
+}
+
+/*
+ * Each session guarantees a negotiated per slot memory cache for replies
+ * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
+ * NFSv4.1 server might want to use more memory for a DRC than a machine
+ * with mutiple services.
+ *
+ * Impose a hard limit on the number of pages for the DRC which varies
+ * according to the machines free pages. This is of course only a default.
+ *
+ * For now this is a #defined shift which could be under admin control
+ * in the future.
+ */
+static void set_max_drc(void)
+{
+ #define NFSD_DRC_SIZE_SHIFT 10
+ nfsd_drc_max_mem = (nr_free_buffer_pages()
+ >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
+ nfsd_drc_mem_used = 0;
+ spin_lock_init(&nfsd_drc_lock);
+ dprintk("%s nfsd_drc_max_mem %u \n", __func__, nfsd_drc_max_mem);
+}
+
+int nfsd_create_serv(void)
+{
+ int err = 0;
+
+ WARN_ON(!mutex_is_locked(&nfsd_mutex));
+ if (nfsd_serv) {
+ svc_get(nfsd_serv);
+ return 0;
+ }
+ if (nfsd_max_blksize == 0) {
+ /* choose a suitable default */
+ struct sysinfo i;
+ si_meminfo(&i);
+ /* Aim for 1/4096 of memory per thread
+ * This gives 1MB on 4Gig machines
+ * But only uses 32K on 128M machines.
+ * Bottom out at 8K on 32M and smaller.
+ * Of course, this is only a default.
+ */
+ nfsd_max_blksize = NFSSVC_MAXBLKSIZE;
+ i.totalram <<= PAGE_SHIFT - 12;
+ while (nfsd_max_blksize > i.totalram &&
+ nfsd_max_blksize >= 8*1024*2)
+ nfsd_max_blksize /= 2;
+ }
+ nfsd_reset_versions();
+
+ nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
+ nfsd_last_thread, nfsd, THIS_MODULE);
+ if (nfsd_serv == NULL)
+ return -ENOMEM;
+
+ set_max_drc();
+ do_gettimeofday(&nfssvc_boot); /* record boot time */
+ return err;
+}
+
+int nfsd_nrpools(void)
+{
+ if (nfsd_serv == NULL)
+ return 0;
+ else
+ return nfsd_serv->sv_nrpools;
+}
+
+int nfsd_get_nrthreads(int n, int *nthreads)
+{
+ int i = 0;
+
+ if (nfsd_serv != NULL) {
+ for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
+ nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
+ }
+
+ return 0;
+}
+
+int nfsd_set_nrthreads(int n, int *nthreads)
+{
+ int i = 0;
+ int tot = 0;
+ int err = 0;
+
+ WARN_ON(!mutex_is_locked(&nfsd_mutex));
+
+ if (nfsd_serv == NULL || n <= 0)
+ return 0;
+
+ if (n > nfsd_serv->sv_nrpools)
+ n = nfsd_serv->sv_nrpools;
+
+ /* enforce a global maximum number of threads */
+ tot = 0;
+ for (i = 0; i < n; i++) {
+ if (nthreads[i] > NFSD_MAXSERVS)
+ nthreads[i] = NFSD_MAXSERVS;
+ tot += nthreads[i];
+ }
+ if (tot > NFSD_MAXSERVS) {
+ /* total too large: scale down requested numbers */
+ for (i = 0; i < n && tot > 0; i++) {
+ int new = nthreads[i] * NFSD_MAXSERVS / tot;
+ tot -= (nthreads[i] - new);
+ nthreads[i] = new;
+ }
+ for (i = 0; i < n && tot > 0; i++) {
+ nthreads[i]--;
+ tot--;
+ }
+ }
+
+ /*
+ * There must always be a thread in pool 0; the admin
+ * can't shut down NFS completely using pool_threads.
+ */
+ if (nthreads[0] == 0)
+ nthreads[0] = 1;
+
+ /* apply the new numbers */
+ svc_get(nfsd_serv);
+ for (i = 0; i < n; i++) {
+ err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
+ nthreads[i]);
+ if (err)
+ break;
+ }
+ svc_destroy(nfsd_serv);
+
+ return err;
+}
+
+/*
+ * Adjust the number of threads and return the new number of threads.
+ * This is also the function that starts the server if necessary, if
+ * this is the first time nrservs is nonzero.
+ */
+int
+nfsd_svc(unsigned short port, int nrservs)
+{
+ int error;
+ bool nfsd_up_before;
+
+ mutex_lock(&nfsd_mutex);
+ dprintk("nfsd: creating service\n");
+ if (nrservs <= 0)
+ nrservs = 0;
+ if (nrservs > NFSD_MAXSERVS)
+ nrservs = NFSD_MAXSERVS;
+ error = 0;
+ if (nrservs == 0 && nfsd_serv == NULL)
+ goto out;
+
+ error = nfsd_create_serv();
+ if (error)
+ goto out;
+
+ nfsd_up_before = nfsd_up;
+
+ error = nfsd_startup(port, nrservs);
+ if (error)
+ goto out_destroy;
+ error = svc_set_num_threads(nfsd_serv, NULL, nrservs);
+ if (error)
+ goto out_shutdown;
+ /* We are holding a reference to nfsd_serv which
+ * we don't want to count in the return value,
+ * so subtract 1
+ */
+ error = nfsd_serv->sv_nrthreads - 1;
+out_shutdown:
+ if (error < 0 && !nfsd_up_before)
+ nfsd_shutdown();
+out_destroy:
+ svc_destroy(nfsd_serv); /* Release server */
+out:
+ mutex_unlock(&nfsd_mutex);
+ return error;
+}
+
+
+/*
+ * This is the NFS server kernel thread
+ */
+static int
+nfsd(void *vrqstp)
+{
+ struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
+ int err, preverr = 0;
+
+ /* Lock module and set up kernel thread */
+ mutex_lock(&nfsd_mutex);
+
+ /* At this point, the thread shares current->fs
+ * with the init process. We need to create files with a
+ * umask of 0 instead of init's umask. */
+ if (unshare_fs_struct() < 0) {
+ printk("Unable to start nfsd thread: out of memory\n");
+ goto out;
+ }
+
+ current->fs->umask = 0;
+
+ /*
+ * thread is spawned with all signals set to SIG_IGN, re-enable
+ * the ones that will bring down the thread
+ */
+ allow_signal(SIGKILL);
+ allow_signal(SIGHUP);
+ allow_signal(SIGINT);
+ allow_signal(SIGQUIT);
+
+ nfsdstats.th_cnt++;
+ mutex_unlock(&nfsd_mutex);
+
+ /*
+ * We want less throttling in balance_dirty_pages() so that nfs to
+ * localhost doesn't cause nfsd to lock up due to all the client's
+ * dirty pages.
+ */
+ current->flags |= PF_LESS_THROTTLE;
+ set_freezable();
+
+ /*
+ * The main request loop
+ */
+ for (;;) {
+ /*
+ * Find a socket with data available and call its
+ * recvfrom routine.
+ */
+ while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
+ ;
+ if (err == -EINTR)
+ break;
+ else if (err < 0) {
+ if (err != preverr) {
+ printk(KERN_WARNING "%s: unexpected error "
+ "from svc_recv (%d)\n", __func__, -err);
+ preverr = err;
+ }
+ schedule_timeout_uninterruptible(HZ);
+ continue;
+ }
+
+ validate_process_creds();
+ svc_process(rqstp);
+ validate_process_creds();
+ }
+
+ /* Clear signals before calling svc_exit_thread() */
+ flush_signals(current);
+
+ mutex_lock(&nfsd_mutex);
+ nfsdstats.th_cnt --;
+
+out:
+ /* Release the thread */
+ svc_exit_thread(rqstp);
+
+ /* Release module */
+ mutex_unlock(&nfsd_mutex);
+ module_put_and_exit(0);
+ return 0;
+}
+
+static __be32 map_new_errors(u32 vers, __be32 nfserr)
+{
+ if (nfserr == nfserr_jukebox && vers == 2)
+ return nfserr_dropit;
+ if (nfserr == nfserr_wrongsec && vers < 4)
+ return nfserr_acces;
+ return nfserr;
+}
+
+int
+nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+{
+ struct svc_procedure *proc;
+ kxdrproc_t xdr;
+ __be32 nfserr;
+ __be32 *nfserrp;
+
+ dprintk("nfsd_dispatch: vers %d proc %d\n",
+ rqstp->rq_vers, rqstp->rq_proc);
+ proc = rqstp->rq_procinfo;
+
+ /*
+ * Give the xdr decoder a chance to change this if it wants
+ * (necessary in the NFSv4.0 compound case)
+ */
+ rqstp->rq_cachetype = proc->pc_cachetype;
+ /* Decode arguments */
+ xdr = proc->pc_decode;
+ if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
+ rqstp->rq_argp)) {
+ dprintk("nfsd: failed to decode arguments!\n");
+ *statp = rpc_garbage_args;
+ return 1;
+ }
+
+ /* Check whether we have this call in the cache. */
+ switch (nfsd_cache_lookup(rqstp)) {
+ case RC_INTR:
+ case RC_DROPIT:
+ return 0;
+ case RC_REPLY:
+ return 1;
+ case RC_DOIT:;
+ /* do it */
+ }
+
+ /* need to grab the location to store the status, as
+ * nfsv4 does some encoding while processing
+ */
+ nfserrp = rqstp->rq_res.head[0].iov_base
+ + rqstp->rq_res.head[0].iov_len;
+ rqstp->rq_res.head[0].iov_len += sizeof(__be32);
+
+ /* Now call the procedure handler, and encode NFS status. */
+ nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
+ nfserr = map_new_errors(rqstp->rq_vers, nfserr);
+ if (nfserr == nfserr_dropit || rqstp->rq_dropme) {
+ dprintk("nfsd: Dropping request; may be revisited later\n");
+ nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
+ return 0;
+ }
+
+ if (rqstp->rq_proc != 0)
+ *nfserrp++ = nfserr;
+
+ /* Encode result.
+ * For NFSv2, additional info is never returned in case of an error.
+ */
+ if (!(nfserr && rqstp->rq_vers == 2)) {
+ xdr = proc->pc_encode;
+ if (xdr && !xdr(rqstp, nfserrp,
+ rqstp->rq_resp)) {
+ /* Failed to encode result. Release cache entry */
+ dprintk("nfsd: failed to encode result!\n");
+ nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
+ *statp = rpc_system_err;
+ return 1;
+ }
+ }
+
+ /* Store reply in cache. */
+ nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
+ return 1;
+}
+
+int nfsd_pool_stats_open(struct inode *inode, struct file *file)
+{
+ int ret;
+ mutex_lock(&nfsd_mutex);
+ if (nfsd_serv == NULL) {
+ mutex_unlock(&nfsd_mutex);
+ return -ENODEV;
+ }
+ /* bump up the psudo refcount while traversing */
+ svc_get(nfsd_serv);
+ ret = svc_pool_stats_open(nfsd_serv, file);
+ mutex_unlock(&nfsd_mutex);
+ return ret;
+}
+
+int nfsd_pool_stats_release(struct inode *inode, struct file *file)
+{
+ int ret = seq_release(inode, file);
+ mutex_lock(&nfsd_mutex);
+ /* this function really, really should have been called svc_put() */
+ svc_destroy(nfsd_serv);
+ mutex_unlock(&nfsd_mutex);
+ return ret;
+}