Revision 9280be24dc9c7aaee230de3ed33f8357386de9a2 authored by Yan, Zheng on 14 October 2014, 02:33:35 UTC, committed by Ilya Dryomov on 17 December 2014, 17:09:49 UTC
When a lock operation is interrupted, current code sends a unlock request to MDS to undo the lock operation. This method does not work as expected because the unlock request can drop locks that have already been acquired. The fix is use the newly introduced CEPH_LOCK_FCNTL_INTR/CEPH_LOCK_FLOCK_INTR requests to interrupt blocked file lock request. These requests do not drop locks that have alread been acquired, they only interrupt blocked file lock request. Signed-off-by: Yan, Zheng <zyan@redhat.com>
1 parent b2776bf
mon.c
/*
* linux/fs/lockd/mon.c
*
* The kernel statd client.
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/slab.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/addr.h>
#include <linux/sunrpc/xprtsock.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <asm/unaligned.h>
#include "netns.h"
#define NLMDBG_FACILITY NLMDBG_MONITOR
#define NSM_PROGRAM 100024
#define NSM_VERSION 1
enum {
NSMPROC_NULL,
NSMPROC_STAT,
NSMPROC_MON,
NSMPROC_UNMON,
NSMPROC_UNMON_ALL,
NSMPROC_SIMU_CRASH,
NSMPROC_NOTIFY,
};
struct nsm_args {
struct nsm_private *priv;
u32 prog; /* RPC callback info */
u32 vers;
u32 proc;
char *mon_name;
char *nodename;
};
struct nsm_res {
u32 status;
u32 state;
};
static const struct rpc_program nsm_program;
static LIST_HEAD(nsm_handles);
static DEFINE_SPINLOCK(nsm_lock);
/*
* Local NSM state
*/
u32 __read_mostly nsm_local_state;
bool __read_mostly nsm_use_hostnames;
static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
{
return (struct sockaddr *)&nsm->sm_addr;
}
static struct rpc_clnt *nsm_create(struct net *net)
{
struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
};
struct rpc_create_args args = {
.net = net,
.protocol = XPRT_TRANSPORT_TCP,
.address = (struct sockaddr *)&sin,
.addrsize = sizeof(sin),
.servername = "rpc.statd",
.program = &nsm_program,
.version = NSM_VERSION,
.authflavor = RPC_AUTH_NULL,
.flags = RPC_CLNT_CREATE_NOPING,
};
return rpc_create(&args);
}
static struct rpc_clnt *nsm_client_set(struct lockd_net *ln,
struct rpc_clnt *clnt)
{
spin_lock(&ln->nsm_clnt_lock);
if (ln->nsm_users == 0) {
if (clnt == NULL)
goto out;
ln->nsm_clnt = clnt;
}
clnt = ln->nsm_clnt;
ln->nsm_users++;
out:
spin_unlock(&ln->nsm_clnt_lock);
return clnt;
}
static struct rpc_clnt *nsm_client_get(struct net *net)
{
struct rpc_clnt *clnt, *new;
struct lockd_net *ln = net_generic(net, lockd_net_id);
clnt = nsm_client_set(ln, NULL);
if (clnt != NULL)
goto out;
clnt = new = nsm_create(net);
if (IS_ERR(clnt))
goto out;
clnt = nsm_client_set(ln, new);
if (clnt != new)
rpc_shutdown_client(new);
out:
return clnt;
}
static void nsm_client_put(struct net *net)
{
struct lockd_net *ln = net_generic(net, lockd_net_id);
struct rpc_clnt *clnt = NULL;
spin_lock(&ln->nsm_clnt_lock);
ln->nsm_users--;
if (ln->nsm_users == 0) {
clnt = ln->nsm_clnt;
ln->nsm_clnt = NULL;
}
spin_unlock(&ln->nsm_clnt_lock);
if (clnt != NULL)
rpc_shutdown_client(clnt);
}
static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
struct rpc_clnt *clnt)
{
int status;
struct nsm_args args = {
.priv = &nsm->sm_priv,
.prog = NLM_PROGRAM,
.vers = 3,
.proc = NLMPROC_NSM_NOTIFY,
.mon_name = nsm->sm_mon_name,
.nodename = clnt->cl_nodename,
};
struct rpc_message msg = {
.rpc_argp = &args,
.rpc_resp = res,
};
memset(res, 0, sizeof(*res));
msg.rpc_proc = &clnt->cl_procinfo[proc];
status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
if (status == -ECONNREFUSED) {
dprintk("lockd: NSM upcall RPC failed, status=%d, forcing rebind\n",
status);
rpc_force_rebind(clnt);
status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
}
if (status < 0)
dprintk("lockd: NSM upcall RPC failed, status=%d\n",
status);
else
status = 0;
return status;
}
/**
* nsm_monitor - Notify a peer in case we reboot
* @host: pointer to nlm_host of peer to notify
*
* If this peer is not already monitored, this function sends an
* upcall to the local rpc.statd to record the name/address of
* the peer to notify in case we reboot.
*
* Returns zero if the peer is monitored by the local rpc.statd;
* otherwise a negative errno value is returned.
*/
int nsm_monitor(const struct nlm_host *host)
{
struct nsm_handle *nsm = host->h_nsmhandle;
struct nsm_res res;
int status;
struct rpc_clnt *clnt;
dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
if (nsm->sm_monitored)
return 0;
/*
* Choose whether to record the caller_name or IP address of
* this peer in the local rpc.statd's database.
*/
nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
clnt = nsm_client_get(host->net);
if (IS_ERR(clnt)) {
status = PTR_ERR(clnt);
dprintk("lockd: failed to create NSM upcall transport, "
"status=%d, net=%p\n", status, host->net);
return status;
}
status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, clnt);
if (unlikely(res.status != 0))
status = -EIO;
if (unlikely(status < 0)) {
printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
return status;
}
nsm->sm_monitored = 1;
if (unlikely(nsm_local_state != res.state)) {
nsm_local_state = res.state;
dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
}
return 0;
}
/**
* nsm_unmonitor - Unregister peer notification
* @host: pointer to nlm_host of peer to stop monitoring
*
* If this peer is monitored, this function sends an upcall to
* tell the local rpc.statd not to send this peer a notification
* when we reboot.
*/
void nsm_unmonitor(const struct nlm_host *host)
{
struct nsm_handle *nsm = host->h_nsmhandle;
struct nsm_res res;
int status;
if (atomic_read(&nsm->sm_count) == 1
&& nsm->sm_monitored && !nsm->sm_sticky) {
struct lockd_net *ln = net_generic(host->net, lockd_net_id);
dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, ln->nsm_clnt);
if (res.status != 0)
status = -EIO;
if (status < 0)
printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
nsm->sm_name);
else
nsm->sm_monitored = 0;
nsm_client_put(host->net);
}
}
static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
const size_t len)
{
struct nsm_handle *nsm;
list_for_each_entry(nsm, &nsm_handles, sm_link)
if (strlen(nsm->sm_name) == len &&
memcmp(nsm->sm_name, hostname, len) == 0)
return nsm;
return NULL;
}
static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
{
struct nsm_handle *nsm;
list_for_each_entry(nsm, &nsm_handles, sm_link)
if (rpc_cmp_addr(nsm_addr(nsm), sap))
return nsm;
return NULL;
}
static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
{
struct nsm_handle *nsm;
list_for_each_entry(nsm, &nsm_handles, sm_link)
if (memcmp(nsm->sm_priv.data, priv->data,
sizeof(priv->data)) == 0)
return nsm;
return NULL;
}
/*
* Construct a unique cookie to match this nsm_handle to this monitored
* host. It is passed to the local rpc.statd via NSMPROC_MON, and
* returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
* requests.
*
* The NSM protocol requires that these cookies be unique while the
* system is running. We prefer a stronger requirement of making them
* unique across reboots. If user space bugs cause a stale cookie to
* be sent to the kernel, it could cause the wrong host to lose its
* lock state if cookies were not unique across reboots.
*
* The cookies are exposed only to local user space via loopback. They
* do not appear on the physical network. If we want greater security
* for some reason, nsm_init_private() could perform a one-way hash to
* obscure the contents of the cookie.
*/
static void nsm_init_private(struct nsm_handle *nsm)
{
u64 *p = (u64 *)&nsm->sm_priv.data;
s64 ns;
ns = ktime_get_ns();
put_unaligned(ns, p);
put_unaligned((unsigned long)nsm, p + 1);
}
static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
const size_t salen,
const char *hostname,
const size_t hostname_len)
{
struct nsm_handle *new;
new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
if (unlikely(new == NULL))
return NULL;
atomic_set(&new->sm_count, 1);
new->sm_name = (char *)(new + 1);
memcpy(nsm_addr(new), sap, salen);
new->sm_addrlen = salen;
nsm_init_private(new);
if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
sizeof(new->sm_addrbuf)) == 0)
(void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
"unsupported address family");
memcpy(new->sm_name, hostname, hostname_len);
new->sm_name[hostname_len] = '\0';
return new;
}
/**
* nsm_get_handle - Find or create a cached nsm_handle
* @sap: pointer to socket address of handle to find
* @salen: length of socket address
* @hostname: pointer to C string containing hostname to find
* @hostname_len: length of C string
*
* Behavior is modulated by the global nsm_use_hostnames variable.
*
* Returns a cached nsm_handle after bumping its ref count, or
* returns a fresh nsm_handle if a handle that matches @sap and/or
* @hostname cannot be found in the handle cache. Returns NULL if
* an error occurs.
*/
struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
const size_t salen, const char *hostname,
const size_t hostname_len)
{
struct nsm_handle *cached, *new = NULL;
if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
if (printk_ratelimit()) {
printk(KERN_WARNING "Invalid hostname \"%.*s\" "
"in NFS lock request\n",
(int)hostname_len, hostname);
}
return NULL;
}
retry:
spin_lock(&nsm_lock);
if (nsm_use_hostnames && hostname != NULL)
cached = nsm_lookup_hostname(hostname, hostname_len);
else
cached = nsm_lookup_addr(sap);
if (cached != NULL) {
atomic_inc(&cached->sm_count);
spin_unlock(&nsm_lock);
kfree(new);
dprintk("lockd: found nsm_handle for %s (%s), "
"cnt %d\n", cached->sm_name,
cached->sm_addrbuf,
atomic_read(&cached->sm_count));
return cached;
}
if (new != NULL) {
list_add(&new->sm_link, &nsm_handles);
spin_unlock(&nsm_lock);
dprintk("lockd: created nsm_handle for %s (%s)\n",
new->sm_name, new->sm_addrbuf);
return new;
}
spin_unlock(&nsm_lock);
new = nsm_create_handle(sap, salen, hostname, hostname_len);
if (unlikely(new == NULL))
return NULL;
goto retry;
}
/**
* nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
* @info: pointer to NLMPROC_SM_NOTIFY arguments
*
* Returns a matching nsm_handle if found in the nsm cache. The returned
* nsm_handle's reference count is bumped. Otherwise returns NULL if some
* error occurred.
*/
struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
{
struct nsm_handle *cached;
spin_lock(&nsm_lock);
cached = nsm_lookup_priv(&info->priv);
if (unlikely(cached == NULL)) {
spin_unlock(&nsm_lock);
dprintk("lockd: never saw rebooted peer '%.*s' before\n",
info->len, info->mon);
return cached;
}
atomic_inc(&cached->sm_count);
spin_unlock(&nsm_lock);
dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
cached->sm_name, cached->sm_addrbuf,
atomic_read(&cached->sm_count));
return cached;
}
/**
* nsm_release - Release an NSM handle
* @nsm: pointer to handle to be released
*
*/
void nsm_release(struct nsm_handle *nsm)
{
if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
list_del(&nsm->sm_link);
spin_unlock(&nsm_lock);
dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
nsm->sm_name, nsm->sm_addrbuf);
kfree(nsm);
}
}
/*
* XDR functions for NSM.
*
* See http://www.opengroup.org/ for details on the Network
* Status Monitor wire protocol.
*/
static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
{
const u32 len = strlen(string);
__be32 *p;
p = xdr_reserve_space(xdr, 4 + len);
xdr_encode_opaque(p, string, len);
}
/*
* "mon_name" specifies the host to be monitored.
*/
static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
{
encode_nsm_string(xdr, argp->mon_name);
}
/*
* The "my_id" argument specifies the hostname and RPC procedure
* to be called when the status manager receives notification
* (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
* has changed.
*/
static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
{
__be32 *p;
encode_nsm_string(xdr, argp->nodename);
p = xdr_reserve_space(xdr, 4 + 4 + 4);
*p++ = cpu_to_be32(argp->prog);
*p++ = cpu_to_be32(argp->vers);
*p = cpu_to_be32(argp->proc);
}
/*
* The "mon_id" argument specifies the non-private arguments
* of an NSMPROC_MON or NSMPROC_UNMON call.
*/
static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
{
encode_mon_name(xdr, argp);
encode_my_id(xdr, argp);
}
/*
* The "priv" argument may contain private information required
* by the NSMPROC_MON call. This information will be supplied in the
* NLMPROC_SM_NOTIFY call.
*/
static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
{
__be32 *p;
p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
}
static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
const struct nsm_args *argp)
{
encode_mon_id(xdr, argp);
encode_priv(xdr, argp);
}
static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
const struct nsm_args *argp)
{
encode_mon_id(xdr, argp);
}
static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
struct nsm_res *resp)
{
__be32 *p;
p = xdr_inline_decode(xdr, 4 + 4);
if (unlikely(p == NULL))
return -EIO;
resp->status = be32_to_cpup(p++);
resp->state = be32_to_cpup(p);
dprintk("lockd: %s status %d state %d\n",
__func__, resp->status, resp->state);
return 0;
}
static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
struct nsm_res *resp)
{
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(p == NULL))
return -EIO;
resp->state = be32_to_cpup(p);
dprintk("lockd: %s state %d\n", __func__, resp->state);
return 0;
}
#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_my_id_sz (SM_my_name_sz+3)
#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
#define SM_monres_sz 2
#define SM_unmonres_sz 1
static struct rpc_procinfo nsm_procedures[] = {
[NSMPROC_MON] = {
.p_proc = NSMPROC_MON,
.p_encode = (kxdreproc_t)nsm_xdr_enc_mon,
.p_decode = (kxdrdproc_t)nsm_xdr_dec_stat_res,
.p_arglen = SM_mon_sz,
.p_replen = SM_monres_sz,
.p_statidx = NSMPROC_MON,
.p_name = "MONITOR",
},
[NSMPROC_UNMON] = {
.p_proc = NSMPROC_UNMON,
.p_encode = (kxdreproc_t)nsm_xdr_enc_unmon,
.p_decode = (kxdrdproc_t)nsm_xdr_dec_stat,
.p_arglen = SM_mon_id_sz,
.p_replen = SM_unmonres_sz,
.p_statidx = NSMPROC_UNMON,
.p_name = "UNMONITOR",
},
};
static const struct rpc_version nsm_version1 = {
.number = 1,
.nrprocs = ARRAY_SIZE(nsm_procedures),
.procs = nsm_procedures
};
static const struct rpc_version *nsm_version[] = {
[1] = &nsm_version1,
};
static struct rpc_stat nsm_stats;
static const struct rpc_program nsm_program = {
.name = "statd",
.number = NSM_PROGRAM,
.nrvers = ARRAY_SIZE(nsm_version),
.version = nsm_version,
.stats = &nsm_stats
};
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