linux/fs/nfsd/nfssvc.c
Linus Torvalds b6669737d3 Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux
Pull nfsd changes from J Bruce Fields:
 "Miscellaneous bugfixes, plus:

   - An overhaul of the DRC cache by Jeff Layton.  The main effect is
     just to make it larger.  This decreases the chances of intermittent
     errors especially in the UDP case.  But we'll need to watch for any
     reports of performance regressions.

   - Containerized nfsd: with some limitations, we now support
     per-container nfs-service, thanks to extensive work from Stanislav
     Kinsbursky over the last year."

Some notes about conflicts, since there were *two* non-data semantic
conflicts here:

 - idr_remove_all() had been added by a memory leak fix, but has since
   become deprecated since idr_destroy() does it for us now.

 - xs_local_connect() had been added by this branch to make AF_LOCAL
   connections be synchronous, but in the meantime Trond had changed the
   calling convention in order to avoid a RCU dereference.

There were a couple of more obvious actual source-level conflicts due to
the hlist traversal changes and one just due to code changes next to
each other, but those were trivial.

* 'for-3.9' of git://linux-nfs.org/~bfields/linux: (49 commits)
  SUNRPC: make AF_LOCAL connect synchronous
  nfsd: fix compiler warning about ambiguous types in nfsd_cache_csum
  svcrpc: fix rpc server shutdown races
  svcrpc: make svc_age_temp_xprts enqueue under sv_lock
  lockd: nlmclnt_reclaim(): avoid stack overflow
  nfsd: enable NFSv4 state in containers
  nfsd: disable usermode helper client tracker in container
  nfsd: use proper net while reading "exports" file
  nfsd: containerize NFSd filesystem
  nfsd: fix comments on nfsd_cache_lookup
  SUNRPC: move cache_detail->cache_request callback call to cache_read()
  SUNRPC: remove "cache_request" argument in sunrpc_cache_pipe_upcall() function
  SUNRPC: rework cache upcall logic
  SUNRPC: introduce cache_detail->cache_request callback
  NFS: simplify and clean cache library
  NFS: use SUNRPC cache creation and destruction helper for DNS cache
  nfsd4: free_stid can be static
  nfsd: keep a checksum of the first 256 bytes of request
  sunrpc: trim off trailing checksum before returning decrypted or integrity authenticated buffer
  sunrpc: fix comment in struct xdr_buf definition
  ...
2013-02-28 18:02:55 -08:00

730 lines
17 KiB
C

/*
* 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"
#include "netns.h"
#define NFSDDBG_FACILITY NFSDDBG_SVC
extern struct svc_program nfsd_program;
static int nfsd(void *vrqstp);
/*
* nfsd_mutex protects nn->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) nn->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);
/*
* 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 long nfsd_drc_max_mem;
unsigned long 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(struct net *net)
{
int rv = 0;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
mutex_lock(&nfsd_mutex);
if (nn->nfsd_serv)
rv = nn->nfsd_serv->sv_nrthreads;
mutex_unlock(&nfsd_mutex);
return rv;
}
static int nfsd_init_socks(struct net *net)
{
int error;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (!list_empty(&nn->nfsd_serv->sv_permsocks))
return 0;
error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
SVC_SOCK_DEFAULTS);
if (error < 0)
return error;
error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
SVC_SOCK_DEFAULTS);
if (error < 0)
return error;
return 0;
}
static int nfsd_users = 0;
static int nfsd_startup_generic(int nrservs)
{
int ret;
if (nfsd_users++)
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 = nfs4_state_start();
if (ret)
goto out_racache;
return 0;
out_racache:
nfsd_racache_shutdown();
return ret;
}
static void nfsd_shutdown_generic(void)
{
if (--nfsd_users)
return;
nfs4_state_shutdown();
nfsd_racache_shutdown();
}
static int nfsd_startup_net(int nrservs, struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
int ret;
if (nn->nfsd_net_up)
return 0;
ret = nfsd_startup_generic(nrservs);
if (ret)
return ret;
ret = nfsd_init_socks(net);
if (ret)
goto out_socks;
ret = lockd_up(net);
if (ret)
goto out_socks;
ret = nfs4_state_start_net(net);
if (ret)
goto out_lockd;
nn->nfsd_net_up = true;
return 0;
out_lockd:
lockd_down(net);
out_socks:
nfsd_shutdown_generic();
return ret;
}
static void nfsd_shutdown_net(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
nfs4_state_shutdown_net(net);
lockd_down(net);
nn->nfsd_net_up = false;
nfsd_shutdown_generic();
}
static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
/*
* 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 (!nn->nfsd_net_up)
return;
nfsd_shutdown_net(net);
svc_rpcb_cleanup(serv, net);
printk(KERN_WARNING "nfsd: last server has exited, flushing export "
"cache\n");
nfsd_export_flush(net);
}
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 %lu \n", __func__, nfsd_drc_max_mem);
}
static int nfsd_get_default_max_blksize(void)
{
struct sysinfo i;
unsigned long long target;
unsigned long ret;
si_meminfo(&i);
target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
/*
* 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.
*/
target >>= 12;
ret = NFSSVC_MAXBLKSIZE;
while (ret > target && ret >= 8*1024*2)
ret /= 2;
return ret;
}
int nfsd_create_serv(struct net *net)
{
int error;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
WARN_ON(!mutex_is_locked(&nfsd_mutex));
if (nn->nfsd_serv) {
svc_get(nn->nfsd_serv);
return 0;
}
if (nfsd_max_blksize == 0)
nfsd_max_blksize = nfsd_get_default_max_blksize();
nfsd_reset_versions();
nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
nfsd_last_thread, nfsd, THIS_MODULE);
if (nn->nfsd_serv == NULL)
return -ENOMEM;
error = svc_bind(nn->nfsd_serv, net);
if (error < 0) {
svc_destroy(nn->nfsd_serv);
return error;
}
set_max_drc();
do_gettimeofday(&nn->nfssvc_boot); /* record boot time */
return 0;
}
int nfsd_nrpools(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (nn->nfsd_serv == NULL)
return 0;
else
return nn->nfsd_serv->sv_nrpools;
}
int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
{
int i = 0;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (nn->nfsd_serv != NULL) {
for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
}
return 0;
}
void nfsd_destroy(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
if (destroy)
svc_shutdown_net(nn->nfsd_serv, net);
svc_destroy(nn->nfsd_serv);
if (destroy)
nn->nfsd_serv = NULL;
}
int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
{
int i = 0;
int tot = 0;
int err = 0;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
WARN_ON(!mutex_is_locked(&nfsd_mutex));
if (nn->nfsd_serv == NULL || n <= 0)
return 0;
if (n > nn->nfsd_serv->sv_nrpools)
n = nn->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(nn->nfsd_serv);
for (i = 0; i < n; i++) {
err = svc_set_num_threads(nn->nfsd_serv, &nn->nfsd_serv->sv_pools[i],
nthreads[i]);
if (err)
break;
}
nfsd_destroy(net);
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(int nrservs, struct net *net)
{
int error;
bool nfsd_up_before;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
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 && nn->nfsd_serv == NULL)
goto out;
error = nfsd_create_serv(net);
if (error)
goto out;
nfsd_up_before = nn->nfsd_net_up;
error = nfsd_startup_net(nrservs, net);
if (error)
goto out_destroy;
error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs);
if (error)
goto out_shutdown;
/* We are holding a reference to nn->nfsd_serv which
* we don't want to count in the return value,
* so subtract 1
*/
error = nn->nfsd_serv->sv_nrthreads - 1;
out_shutdown:
if (error < 0 && !nfsd_up_before)
nfsd_shutdown_net(net);
out_destroy:
nfsd_destroy(net); /* 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;
struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
struct net *net = perm_sock->xpt_net;
int err;
/* 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;
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:
rqstp->rq_server = NULL;
/* Release the thread */
svc_exit_thread(rqstp);
nfsd_destroy(net);
/* 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_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, rqstp->rq_cachetype, statp + 1);
return 1;
}
int nfsd_pool_stats_open(struct inode *inode, struct file *file)
{
int ret;
struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
mutex_lock(&nfsd_mutex);
if (nn->nfsd_serv == NULL) {
mutex_unlock(&nfsd_mutex);
return -ENODEV;
}
/* bump up the psudo refcount while traversing */
svc_get(nn->nfsd_serv);
ret = svc_pool_stats_open(nn->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);
struct net *net = inode->i_sb->s_fs_info;
mutex_lock(&nfsd_mutex);
/* this function really, really should have been called svc_put() */
nfsd_destroy(net);
mutex_unlock(&nfsd_mutex);
return ret;
}