diff options
author | David S. Miller <davem@davemloft.net> | 2009-01-08 11:05:59 -0800 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2009-01-08 11:05:59 -0800 |
commit | 7f46b1343f723f98634a5dcee47856b2000079ed (patch) | |
tree | ed22b6298c8dd2f687890a0d79abcd1d273b5f81 /fs/lockd/mon.c | |
parent | b8c31da64165b8566fc6e1c9c826f76e7b98ff02 (diff) | |
parent | 9e42d0cf5020aaf217433cad1a224745241d212a (diff) |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'fs/lockd/mon.c')
-rw-r--r-- | fs/lockd/mon.c | 569 |
1 files changed, 424 insertions, 145 deletions
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c index ffd3461f75e..5e2c4d5ac82 100644 --- a/fs/lockd/mon.c +++ b/fs/lockd/mon.c @@ -9,35 +9,123 @@ #include <linux/types.h> #include <linux/utsname.h> #include <linux/kernel.h> +#include <linux/ktime.h> + #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/xprtsock.h> #include <linux/sunrpc/svc.h> #include <linux/lockd/lockd.h> -#include <linux/lockd/sm_inter.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; -#define XDR_ADDRBUF_LEN (20) + char *mon_name; +}; -static struct rpc_clnt * nsm_create(void); +struct nsm_res { + u32 status; + u32 state; +}; static struct rpc_program nsm_program; +static LIST_HEAD(nsm_handles); +static DEFINE_SPINLOCK(nsm_lock); /* * Local NSM state */ -int nsm_local_state; +int __read_mostly nsm_local_state; +int __read_mostly nsm_use_hostnames; -/* - * Common procedure for SM_MON/SM_UNMON calls - */ -static int -nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res) +static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm) +{ + return (struct sockaddr *)&nsm->sm_addr; +} + +static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf, + const size_t len) +{ + const struct sockaddr_in *sin = (struct sockaddr_in *)sap; + snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr); +} + +static void nsm_display_ipv6_address(const struct sockaddr *sap, char *buf, + const size_t len) +{ + const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap; + + if (ipv6_addr_v4mapped(&sin6->sin6_addr)) + snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]); + else if (sin6->sin6_scope_id != 0) + snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr, + sin6->sin6_scope_id); + else + snprintf(buf, len, "%pI6", &sin6->sin6_addr); +} + +static void nsm_display_address(const struct sockaddr *sap, + char *buf, const size_t len) +{ + switch (sap->sa_family) { + case AF_INET: + nsm_display_ipv4_address(sap, buf, len); + break; + case AF_INET6: + nsm_display_ipv6_address(sap, buf, len); + break; + default: + snprintf(buf, len, "unsupported address family"); + break; + } +} + +static struct rpc_clnt *nsm_create(void) +{ + struct sockaddr_in sin = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_LOOPBACK), + }; + struct rpc_create_args args = { + .protocol = XPRT_TRANSPORT_UDP, + .address = (struct sockaddr *)&sin, + .addrsize = sizeof(sin), + .servername = "rpc.statd", + .program = &nsm_program, + .version = NSM_VERSION, + .authflavor = RPC_AUTH_NULL, + }; + + return rpc_create(&args); +} + +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; + struct nsm_args args = { + .priv = &nsm->sm_priv, + .prog = NLM_PROGRAM, + .vers = 3, + .proc = NLMPROC_NSM_NOTIFY, + .mon_name = nsm->sm_mon_name, + }; struct rpc_message msg = { .rpc_argp = &args, .rpc_resp = res, @@ -46,22 +134,18 @@ nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res) clnt = nsm_create(); if (IS_ERR(clnt)) { status = PTR_ERR(clnt); + dprintk("lockd: failed to create NSM upcall transport, " + "status=%d\n", status); goto out; } - memset(&args, 0, sizeof(args)); - args.mon_name = nsm->sm_name; - args.addr = nsm_addr_in(nsm)->sin_addr.s_addr; - args.prog = NLM_PROGRAM; - args.vers = 3; - args.proc = NLMPROC_NSM_NOTIFY; memset(res, 0, sizeof(*res)); msg.rpc_proc = &clnt->cl_procinfo[proc]; status = rpc_call_sync(clnt, &msg, 0); if (status < 0) - printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n", - status); + dprintk("lockd: NSM upcall RPC failed, status=%d\n", + status); else status = 0; rpc_shutdown_client(clnt); @@ -69,82 +153,272 @@ nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res) return status; } -/* - * Set up monitoring of a remote host +/** + * 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(struct nlm_host *host) +int nsm_monitor(const struct nlm_host *host) { struct nsm_handle *nsm = host->h_nsmhandle; struct nsm_res res; int status; - dprintk("lockd: nsm_monitor(%s)\n", host->h_name); - BUG_ON(nsm == NULL); + dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name); if (nsm->sm_monitored) return 0; - status = nsm_mon_unmon(nsm, SM_MON, &res); + /* + * 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; - if (status < 0 || res.status != 0) - printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name); + status = nsm_mon_unmon(nsm, NSMPROC_MON, &res); + if (res.status != 0) + status = -EIO; + if (status < 0) + printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name); else nsm->sm_monitored = 1; return status; } -/* - * Cease to monitor remote host +/** + * 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. */ -int -nsm_unmonitor(struct nlm_host *host) +void nsm_unmonitor(const struct nlm_host *host) { struct nsm_handle *nsm = host->h_nsmhandle; struct nsm_res res; - int status = 0; - - if (nsm == NULL) - return 0; - host->h_nsmhandle = NULL; + int status; if (atomic_read(&nsm->sm_count) == 1 && nsm->sm_monitored && !nsm->sm_sticky) { - dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name); + dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name); - status = nsm_mon_unmon(nsm, SM_UNMON, &res); + status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res); + if (res.status != 0) + status = -EIO; if (status < 0) printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", - host->h_name); + nsm->sm_name); else nsm->sm_monitored = 0; } - nsm_release(nsm); - return status; +} + +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 (nlm_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; } /* - * Create NSM client for the local host + * 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 struct rpc_clnt * -nsm_create(void) +static void nsm_init_private(struct nsm_handle *nsm) { - struct sockaddr_in sin = { - .sin_family = AF_INET, - .sin_addr.s_addr = htonl(INADDR_LOOPBACK), - .sin_port = 0, - }; - struct rpc_create_args args = { - .protocol = XPRT_TRANSPORT_UDP, - .address = (struct sockaddr *)&sin, - .addrsize = sizeof(sin), - .servername = "localhost", - .program = &nsm_program, - .version = SM_VERSION, - .authflavor = RPC_AUTH_NULL, - }; + u64 *p = (u64 *)&nsm->sm_priv.data; + struct timespec ts; - return rpc_create(&args); + ktime_get_ts(&ts); + *p++ = timespec_to_ns(&ts); + *p = (unsigned long)nsm; +} + +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); + nsm_display_address((const struct sockaddr *)&new->sm_addr, + new->sm_addrbuf, sizeof(new->sm_addrbuf)); + 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 and sm_monitored is cleared. + * 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); + + /* + * During subsequent lock activity, force a fresh + * notification to be set up for this host. + */ + cached->sm_monitored = 0; + + 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); + } } /* @@ -154,127 +428,132 @@ nsm_create(void) * Status Monitor wire protocol. */ -static __be32 *xdr_encode_nsm_string(__be32 *p, char *string) +static int encode_nsm_string(struct xdr_stream *xdr, const char *string) { - size_t len = strlen(string); - - if (len > SM_MAXSTRLEN) - len = SM_MAXSTRLEN; - return xdr_encode_opaque(p, string, len); + const u32 len = strlen(string); + __be32 *p; + + if (unlikely(len > SM_MAXSTRLEN)) + return -EIO; + p = xdr_reserve_space(xdr, sizeof(u32) + len); + if (unlikely(p == NULL)) + return -EIO; + xdr_encode_opaque(p, string, len); + return 0; } /* * "mon_name" specifies the host to be monitored. - * - * Linux uses a text version of the IP address of the remote - * host as the host identifier (the "mon_name" argument). - * - * Linux statd always looks up the canonical hostname first for - * whatever remote hostname it receives, so this works alright. */ -static __be32 *xdr_encode_mon_name(__be32 *p, struct nsm_args *argp) +static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp) { - char buffer[XDR_ADDRBUF_LEN + 1]; - char *name = argp->mon_name; - - if (!nsm_use_hostnames) { - snprintf(buffer, XDR_ADDRBUF_LEN, - "%pI4", &argp->addr); - name = buffer; - } - - return xdr_encode_nsm_string(p, name); + return 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 SM_NOTIFY call) that the state of host "mon_name" + * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name" * has changed. */ -static __be32 *xdr_encode_my_id(__be32 *p, struct nsm_args *argp) +static int encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp) { - p = xdr_encode_nsm_string(p, utsname()->nodename); - if (!p) - return ERR_PTR(-EIO); - + int status; + __be32 *p; + + status = encode_nsm_string(xdr, utsname()->nodename); + if (unlikely(status != 0)) + return status; + p = xdr_reserve_space(xdr, 3 * sizeof(u32)); + if (unlikely(p == NULL)) + return -EIO; *p++ = htonl(argp->prog); *p++ = htonl(argp->vers); *p++ = htonl(argp->proc); - - return p; + return 0; } /* * The "mon_id" argument specifies the non-private arguments - * of an SM_MON or SM_UNMON call. + * of an NSMPROC_MON or NSMPROC_UNMON call. */ -static __be32 *xdr_encode_mon_id(__be32 *p, struct nsm_args *argp) +static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp) { - p = xdr_encode_mon_name(p, argp); - if (!p) - return ERR_PTR(-EIO); + int status; - return xdr_encode_my_id(p, argp); + status = encode_mon_name(xdr, argp); + if (unlikely(status != 0)) + return status; + return encode_my_id(xdr, argp); } /* * The "priv" argument may contain private information required - * by the SM_MON call. This information will be supplied in the - * SM_NOTIFY call. - * - * Linux provides the raw IP address of the monitored host, - * left in network byte order. + * by the NSMPROC_MON call. This information will be supplied in the + * NLMPROC_SM_NOTIFY call. */ -static __be32 *xdr_encode_priv(__be32 *p, struct nsm_args *argp) +static int encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp) { - *p++ = argp->addr; - *p++ = 0; - *p++ = 0; - *p++ = 0; + __be32 *p; - return p; + p = xdr_reserve_space(xdr, SM_PRIV_SIZE); + if (unlikely(p == NULL)) + return -EIO; + xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE); + return 0; } -static int -xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) +static int xdr_enc_mon(struct rpc_rqst *req, __be32 *p, + const struct nsm_args *argp) { - p = xdr_encode_mon_id(p, argp); - if (IS_ERR(p)) - return PTR_ERR(p); - - p = xdr_encode_priv(p, argp); - if (IS_ERR(p)) - return PTR_ERR(p); - - rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); - return 0; + struct xdr_stream xdr; + int status; + + xdr_init_encode(&xdr, &req->rq_snd_buf, p); + status = encode_mon_id(&xdr, argp); + if (unlikely(status)) + return status; + return encode_priv(&xdr, argp); } -static int -xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) +static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p, + const struct nsm_args *argp) { - p = xdr_encode_mon_id(p, argp); - if (IS_ERR(p)) - return PTR_ERR(p); - rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); - return 0; + struct xdr_stream xdr; + + xdr_init_encode(&xdr, &req->rq_snd_buf, p); + return encode_mon_id(&xdr, argp); } -static int -xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) +static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p, + struct nsm_res *resp) { + struct xdr_stream xdr; + + xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); + p = xdr_inline_decode(&xdr, 2 * sizeof(u32)); + if (unlikely(p == NULL)) + return -EIO; resp->status = ntohl(*p++); - resp->state = ntohl(*p++); - dprintk("nsm: xdr_decode_stat_res status %d state %d\n", + resp->state = ntohl(*p); + + dprintk("lockd: xdr_dec_stat_res status %d state %d\n", resp->status, resp->state); return 0; } -static int -xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) +static int xdr_dec_stat(struct rpc_rqst *rqstp, __be32 *p, + struct nsm_res *resp) { - resp->state = ntohl(*p++); + struct xdr_stream xdr; + + xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); + p = xdr_inline_decode(&xdr, sizeof(u32)); + if (unlikely(p == NULL)) + return -EIO; + resp->state = ntohl(*p); + + dprintk("lockd: xdr_dec_stat state %d\n", resp->state); return 0; } @@ -288,22 +567,22 @@ xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) #define SM_unmonres_sz 1 static struct rpc_procinfo nsm_procedures[] = { -[SM_MON] = { - .p_proc = SM_MON, - .p_encode = (kxdrproc_t) xdr_encode_mon, - .p_decode = (kxdrproc_t) xdr_decode_stat_res, +[NSMPROC_MON] = { + .p_proc = NSMPROC_MON, + .p_encode = (kxdrproc_t)xdr_enc_mon, + .p_decode = (kxdrproc_t)xdr_dec_stat_res, .p_arglen = SM_mon_sz, .p_replen = SM_monres_sz, - .p_statidx = SM_MON, + .p_statidx = NSMPROC_MON, .p_name = "MONITOR", }, -[SM_UNMON] = { - .p_proc = SM_UNMON, - .p_encode = (kxdrproc_t) xdr_encode_unmon, - .p_decode = (kxdrproc_t) xdr_decode_stat, +[NSMPROC_UNMON] = { + .p_proc = NSMPROC_UNMON, + .p_encode = (kxdrproc_t)xdr_enc_unmon, + .p_decode = (kxdrproc_t)xdr_dec_stat, .p_arglen = SM_mon_id_sz, .p_replen = SM_unmonres_sz, - .p_statidx = SM_UNMON, + .p_statidx = NSMPROC_UNMON, .p_name = "UNMONITOR", }, }; @@ -322,7 +601,7 @@ static struct rpc_stat nsm_stats; static struct rpc_program nsm_program = { .name = "statd", - .number = SM_PROGRAM, + .number = NSM_PROGRAM, .nrvers = ARRAY_SIZE(nsm_version), .version = nsm_version, .stats = &nsm_stats |