NFS: Parse and store all multipath DS addresses
authorWeston Andros Adamson <dros@netapp.com>
Tue, 31 May 2011 22:48:57 +0000 (18:48 -0400)
committerTrond Myklebust <Trond.Myklebust@netapp.com>
Tue, 12 Jul 2011 17:40:27 +0000 (13:40 -0400)
This parses and stores all addresses associated with each data server,
laying the groundwork for supporting multipath to data servers.

 - Skips over addresses that cannot be parsed (ie IPv6 addrs if v6 is not
   enabled).  Only fails if none of the addresses are recognizable
 - Currently only uses the first address that parsed cleanly
 - Tested against pynfs server (modified to support multipath)

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
fs/nfs/nfs4filelayout.h
fs/nfs/nfs4filelayoutdev.c

index 6c6a817..68cce73 100644 (file)
@@ -47,11 +47,17 @@ enum stripetype4 {
 };
 
 /* Individual ip address */
+struct nfs4_pnfs_ds_addr {
+       struct sockaddr_storage da_addr;
+       size_t                  da_addrlen;
+       struct list_head        da_node;  /* nfs4_pnfs_dev_hlist dev_dslist */
+       char                    *da_remotestr;  /* human readable addr+port */
+};
+
 struct nfs4_pnfs_ds {
        struct list_head        ds_node;  /* nfs4_pnfs_dev_hlist dev_dslist */
-       struct sockaddr_storage ds_addr;
-       size_t                  ds_addrlen;
-       char                    *ds_remotestr;  /* human readable addr+port */
+       char                    *ds_remotestr;  /* comma sep list of addrs */
+       struct list_head        ds_addrs;
        struct nfs_client       *ds_clp;
        atomic_t                ds_count;
 };
index 1a8308b..610808a 100644 (file)
@@ -65,52 +65,103 @@ print_ds(struct nfs4_pnfs_ds *ds)
                ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
 }
 
-/* nfs4_ds_cache_lock is held */
-static struct nfs4_pnfs_ds *
-_data_server_lookup_locked(struct sockaddr *addr, size_t addrlen)
+static bool
+same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
 {
-       struct nfs4_pnfs_ds *ds;
        struct sockaddr_in *a, *b;
        struct sockaddr_in6 *a6, *b6;
 
-       list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) {
-               if (addr->sa_family != ds->ds_addr.ss_family)
-                       continue;
-
-               switch (addr->sa_family) {
-               case AF_INET:
-                       a = (struct sockaddr_in *)addr;
-                       b = (struct sockaddr_in *)&ds->ds_addr;
-
-                       if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
-                           a->sin_port == b->sin_port)
-                               return ds;
-                       break;
-
-               case AF_INET6:
-                       a6 = (struct sockaddr_in6 *)addr;
-                       b6 = (struct sockaddr_in6 *)&ds->ds_addr;
-
-                       /* LINKLOCAL addresses must have matching scope_id */
-                       if (ipv6_addr_scope(&a6->sin6_addr) ==
-                           IPV6_ADDR_SCOPE_LINKLOCAL &&
-                           a6->sin6_scope_id != b6->sin6_scope_id)
-                               continue;
-
-                       if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
-                           a6->sin6_port == b6->sin6_port)
-                               return ds;
-                       break;
-
-               default:
-                       dprintk("%s: unhandled address family: %u\n",
-                               __func__, addr->sa_family);
-                       return NULL;
+       if (addr1->sa_family != addr2->sa_family)
+               return false;
+
+       switch (addr1->sa_family) {
+       case AF_INET:
+               a = (struct sockaddr_in *)addr1;
+               b = (struct sockaddr_in *)addr2;
+
+               if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
+                   a->sin_port == b->sin_port)
+                       return true;
+               break;
+
+       case AF_INET6:
+               a6 = (struct sockaddr_in6 *)addr1;
+               b6 = (struct sockaddr_in6 *)addr2;
+
+               /* LINKLOCAL addresses must have matching scope_id */
+               if (ipv6_addr_scope(&a6->sin6_addr) ==
+                   IPV6_ADDR_SCOPE_LINKLOCAL &&
+                   a6->sin6_scope_id != b6->sin6_scope_id)
+                       return false;
+
+               if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
+                   a6->sin6_port == b6->sin6_port)
+                       return true;
+               break;
+
+       default:
+               dprintk("%s: unhandled address family: %u\n",
+                       __func__, addr1->sa_family);
+               return false;
+       }
+
+       return false;
+}
+
+/*
+ * Lookup DS by addresses.  The first matching address returns true.
+ * nfs4_ds_cache_lock is held
+ */
+static struct nfs4_pnfs_ds *
+_data_server_lookup_locked(struct list_head *dsaddrs)
+{
+       struct nfs4_pnfs_ds *ds;
+       struct nfs4_pnfs_ds_addr *da1, *da2;
+
+       list_for_each_entry(da1, dsaddrs, da_node) {
+               list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) {
+                       list_for_each_entry(da2, &ds->ds_addrs, da_node) {
+                               if (same_sockaddr(
+                                       (struct sockaddr *)&da1->da_addr,
+                                       (struct sockaddr *)&da2->da_addr))
+                                       return ds;
+                       }
                }
        }
        return NULL;
 }
 
+/*
+ * Compare two lists of addresses.
+ */
+static bool
+_data_server_match_all_addrs_locked(struct list_head *dsaddrs1,
+                                   struct list_head *dsaddrs2)
+{
+       struct nfs4_pnfs_ds_addr *da1, *da2;
+       size_t count1 = 0,
+              count2 = 0;
+
+       list_for_each_entry(da1, dsaddrs1, da_node)
+               count1++;
+
+       list_for_each_entry(da2, dsaddrs2, da_node) {
+               bool found = false;
+               count2++;
+               list_for_each_entry(da1, dsaddrs1, da_node) {
+                       if (same_sockaddr((struct sockaddr *)&da1->da_addr,
+                               (struct sockaddr *)&da2->da_addr)) {
+                               found = true;
+                               break;
+                       }
+               }
+               if (!found)
+                       return false;
+       }
+
+       return (count1 == count2);
+}
+
 /*
  * Create an rpc connection to the nfs4_pnfs_ds data server
  * Currently only support IPv4
@@ -119,14 +170,21 @@ static int
 nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds)
 {
        struct nfs_client *clp;
+       struct nfs4_pnfs_ds_addr *da;
        int status = 0;
 
-       dprintk("--> %s addr %s au_flavor %d\n", __func__, ds->ds_remotestr,
+       dprintk("--> %s DS %s au_flavor %d\n", __func__, ds->ds_remotestr,
                mds_srv->nfs_client->cl_rpcclient->cl_auth->au_flavor);
 
+       BUG_ON(list_empty(&ds->ds_addrs));
+
+       da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
+       dprintk("%s: using the first address for DS %s: %s\n",
+               __func__, ds->ds_remotestr, da->da_remotestr);
+
        clp = nfs4_set_ds_client(mds_srv->nfs_client,
-                                (struct sockaddr *)&ds->ds_addr,
-                                ds->ds_addrlen, IPPROTO_TCP);
+                                (struct sockaddr *)&da->da_addr,
+                                da->da_addrlen, IPPROTO_TCP);
        if (IS_ERR(clp)) {
                status = PTR_ERR(clp);
                goto out;
@@ -169,12 +227,24 @@ out_put:
 static void
 destroy_ds(struct nfs4_pnfs_ds *ds)
 {
+       struct nfs4_pnfs_ds_addr *da;
+
        dprintk("--> %s\n", __func__);
        ifdebug(FACILITY)
                print_ds(ds);
 
        if (ds->ds_clp)
                nfs_put_client(ds->ds_clp);
+
+       while (!list_empty(&ds->ds_addrs)) {
+               da = list_first_entry(&ds->ds_addrs,
+                                     struct nfs4_pnfs_ds_addr,
+                                     da_node);
+               list_del_init(&da->da_node);
+               kfree(da->da_remotestr);
+               kfree(da);
+       }
+
        kfree(ds->ds_remotestr);
        kfree(ds);
 }
@@ -207,67 +277,73 @@ nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
  * complicated setup around many dprinks.
  */
 static char *
-nfs4_pnfs_remotestr(struct sockaddr *ds_addr, gfp_t gfp_flags)
+nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
 {
-       char buf[INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN];
+       struct nfs4_pnfs_ds_addr *da;
        char *remotestr;
-       char *startsep = "";
-       char *endsep = "";
        size_t len;
-       uint16_t port;
+       char *p;
 
-       switch (ds_addr->sa_family) {
-       case AF_INET:
-               port = ((struct sockaddr_in *)ds_addr)->sin_port;
-               break;
-       case AF_INET6:
-               startsep = "[";
-               endsep = "]";
-               port = ((struct sockaddr_in6 *)ds_addr)->sin6_port;
-               break;
-       default:
-               dprintk("%s: Unknown address family %u\n",
-                       __func__, ds_addr->sa_family);
-               return NULL;
+       len = 3;        /* '{', '}' and eol */
+       list_for_each_entry(da, dsaddrs, da_node) {
+               len += strlen(da->da_remotestr) + 1;    /* string plus comma */
        }
 
-       if (!rpc_ntop((struct sockaddr *)ds_addr, buf, sizeof(buf))) {
-               dprintk("%s: error printing addr\n", __func__);
+       remotestr = kzalloc(len, gfp_flags);
+       if (!remotestr)
                return NULL;
-       }
 
-       len = strlen(buf) + strlen(startsep) + strlen(endsep) + 1 + 5 + 1;
-       remotestr = kzalloc(len, gfp_flags);
+       p = remotestr;
+       *(p++) = '{';
+       len--;
+       list_for_each_entry(da, dsaddrs, da_node) {
+               size_t ll = strlen(da->da_remotestr);
 
-       if (unlikely(!remotestr)) {
-               dprintk("%s: couldn't alloc remotestr\n", __func__);
-               return NULL;
-       }
+               if (ll > len)
+                       goto out_err;
 
-       snprintf(remotestr, len, "%s%s%s:%u",
-                startsep, buf, endsep, ntohs(port));
+               memcpy(p, da->da_remotestr, ll);
+               p += ll;
+               len -= ll;
 
+               if (len < 1)
+                       goto out_err;
+               (*p++) = ',';
+               len--;
+       }
+       if (len < 2)
+               goto out_err;
+       *(p++) = '}';
+       *p = '\0';
        return remotestr;
+out_err:
+       kfree(remotestr);
+       return NULL;
 }
 
 static struct nfs4_pnfs_ds *
-nfs4_pnfs_ds_add(struct sockaddr *addr, size_t addrlen, gfp_t gfp_flags)
+nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
 {
        struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
        char *remotestr;
 
-       ds = kzalloc(sizeof(*tmp_ds), gfp_flags);
+       if (list_empty(dsaddrs)) {
+               dprintk("%s: no addresses defined\n", __func__);
+               goto out;
+       }
+
+       ds = kzalloc(sizeof(*ds), gfp_flags);
        if (!ds)
                goto out;
 
        /* this is only used for debugging, so it's ok if its NULL */
-       remotestr = nfs4_pnfs_remotestr(addr, gfp_flags);
+       remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
 
        spin_lock(&nfs4_ds_cache_lock);
-       tmp_ds = _data_server_lookup_locked(addr, addrlen);
+       tmp_ds = _data_server_lookup_locked(dsaddrs);
        if (tmp_ds == NULL) {
-               memcpy(&ds->ds_addr, addr, addrlen);
-               ds->ds_addrlen = addrlen;
+               INIT_LIST_HEAD(&ds->ds_addrs);
+               list_splice_init(dsaddrs, &ds->ds_addrs);
                ds->ds_remotestr = remotestr;
                atomic_set(&ds->ds_count, 1);
                INIT_LIST_HEAD(&ds->ds_node);
@@ -276,6 +352,11 @@ nfs4_pnfs_ds_add(struct sockaddr *addr, size_t addrlen, gfp_t gfp_flags)
                dprintk("%s add new data server %s\n", __func__,
                        ds->ds_remotestr);
        } else {
+               if (!_data_server_match_all_addrs_locked(&tmp_ds->ds_addrs,
+                                                        dsaddrs)) {
+                       dprintk("%s:  multipath address mismatch: %s != %s",
+                               __func__, tmp_ds->ds_remotestr, remotestr);
+               }
                kfree(remotestr);
                kfree(ds);
                atomic_inc(&tmp_ds->ds_count);
@@ -292,19 +373,20 @@ out:
 /*
  * Currently only supports ipv4, ipv6 and one multi-path address.
  */
-static struct nfs4_pnfs_ds *
-decode_and_add_ds(struct xdr_stream *streamp, struct inode *inode, gfp_t gfp_flags)
+static struct nfs4_pnfs_ds_addr *
+decode_ds_addr(struct xdr_stream *streamp, gfp_t gfp_flags)
 {
-       struct nfs4_pnfs_ds *ds = NULL;
+       struct nfs4_pnfs_ds_addr *da = NULL;
        char *buf, *portstr;
-       struct sockaddr_storage ss;
-       size_t sslen;
        u32 port;
        int nlen, rlen;
        int tmp[2];
        __be32 *p;
        char *netid, *match_netid;
-       size_t match_netid_len;
+       size_t len, match_netid_len;
+       char *startsep = "";
+       char *endsep = "";
+
 
        /* r_netid */
        p = xdr_inline_decode(streamp, 4);
@@ -365,50 +447,74 @@ decode_and_add_ds(struct xdr_stream *streamp, struct inode *inode, gfp_t gfp_fla
        }
        *portstr = '\0';
 
-       if (!rpc_pton(buf, portstr-buf, (struct sockaddr *)&ss, sizeof(ss))) {
-               dprintk("%s: Error parsing address %s\n", __func__, buf);
+       da = kzalloc(sizeof(*da), gfp_flags);
+       if (unlikely(!da))
                goto out_free_buf;
+
+       INIT_LIST_HEAD(&da->da_node);
+
+       if (!rpc_pton(buf, portstr-buf, (struct sockaddr *)&da->da_addr,
+                     sizeof(da->da_addr))) {
+               dprintk("%s: error parsing address %s\n", __func__, buf);
+               goto out_free_da;
        }
 
        portstr++;
        sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
        port = htons((tmp[0] << 8) | (tmp[1]));
 
-       switch (ss.ss_family) {
+       switch (da->da_addr.ss_family) {
        case AF_INET:
-               ((struct sockaddr_in *)&ss)->sin_port = port;
-               sslen = sizeof(struct sockaddr_in);
+               ((struct sockaddr_in *)&da->da_addr)->sin_port = port;
+               da->da_addrlen = sizeof(struct sockaddr_in);
                match_netid = "tcp";
                match_netid_len = 3;
                break;
 
        case AF_INET6:
-               ((struct sockaddr_in6 *)&ss)->sin6_port = port;
-               sslen = sizeof(struct sockaddr_in6);
+               ((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
+               da->da_addrlen = sizeof(struct sockaddr_in6);
                match_netid = "tcp6";
                match_netid_len = 4;
+               startsep = "[";
+               endsep = "]";
                break;
 
        default:
                dprintk("%s: unsupported address family: %u\n",
-                       __func__, ss.ss_family);
-               goto out_free_buf;
+                       __func__, da->da_addr.ss_family);
+               goto out_free_da;
        }
 
        if (nlen != match_netid_len || strncmp(netid, match_netid, nlen)) {
                dprintk("%s: ERROR: r_netid \"%s\" != \"%s\"\n",
                        __func__, netid, match_netid);
-               goto out_free_buf;
+               goto out_free_da;
        }
 
-       ds = nfs4_pnfs_ds_add((struct sockaddr *)&ss, sslen, gfp_flags);
-       dprintk("%s: Added DS %s\n", __func__, ds->ds_remotestr);
+       /* save human readable address */
+       len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
+       da->da_remotestr = kzalloc(len, gfp_flags);
+
+       /* NULL is ok, only used for dprintk */
+       if (da->da_remotestr)
+               snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
+                        buf, endsep, ntohs(port));
+
+       dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
+       kfree(buf);
+       kfree(netid);
+       return da;
+
+out_free_da:
+       kfree(da);
 out_free_buf:
+       dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
        kfree(buf);
 out_free_netid:
        kfree(netid);
 out_err:
-       return ds;
+       return NULL;
 }
 
 /* Decode opaque device data and return the result */
@@ -425,6 +531,8 @@ decode_device(struct inode *ino, struct pnfs_device *pdev, gfp_t gfp_flags)
        struct xdr_stream stream;
        struct xdr_buf buf;
        struct page *scratch;
+       struct list_head dsaddrs;
+       struct nfs4_pnfs_ds_addr *da;
 
        /* set up xdr stream */
        scratch = alloc_page(gfp_flags);
@@ -501,6 +609,8 @@ decode_device(struct inode *ino, struct pnfs_device *pdev, gfp_t gfp_flags)
                                NFS_SERVER(ino)->nfs_client,
                                &pdev->dev_id);
 
+       INIT_LIST_HEAD(&dsaddrs);
+
        for (i = 0; i < dsaddr->ds_num; i++) {
                int j;
                u32 mp_count;
@@ -510,48 +620,43 @@ decode_device(struct inode *ino, struct pnfs_device *pdev, gfp_t gfp_flags)
                        goto out_err_free_deviceid;
 
                mp_count = be32_to_cpup(p); /* multipath count */
-               if (mp_count > 1) {
-                       printk(KERN_WARNING
-                              "%s: Multipath count %d not supported, "
-                              "skipping all greater than 1\n", __func__,
-                               mp_count);
-               }
                for (j = 0; j < mp_count; j++) {
-                       if (j == 0) {
-                               dsaddr->ds_list[i] = decode_and_add_ds(&stream,
-                                       ino, gfp_flags);
-                               if (dsaddr->ds_list[i] == NULL)
-                                       goto out_err_free_deviceid;
-                       } else {
-                               u32 len;
-                               /* skip extra multipath */
-
-                               /* read len, skip */
-                               p = xdr_inline_decode(&stream, 4);
-                               if (unlikely(!p))
-                                       goto out_err_free_deviceid;
-                               len = be32_to_cpup(p);
-
-                               p = xdr_inline_decode(&stream, len);
-                               if (unlikely(!p))
-                                       goto out_err_free_deviceid;
-
-                               /* read len, skip */
-                               p = xdr_inline_decode(&stream, 4);
-                               if (unlikely(!p))
-                                       goto out_err_free_deviceid;
-                               len = be32_to_cpup(p);
-
-                               p = xdr_inline_decode(&stream, len);
-                               if (unlikely(!p))
-                                       goto out_err_free_deviceid;
-                       }
+                       da = decode_ds_addr(&stream, gfp_flags);
+                       if (da)
+                               list_add_tail(&da->da_node, &dsaddrs);
+               }
+               if (list_empty(&dsaddrs)) {
+                       dprintk("%s: no suitable DS addresses found\n",
+                               __func__);
+                       goto out_err_free_deviceid;
+               }
+
+               dsaddr->ds_list[i] = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
+               if (!dsaddr->ds_list[i])
+                       goto out_err_drain_dsaddrs;
+
+               /* If DS was already in cache, free ds addrs */
+               while (!list_empty(&dsaddrs)) {
+                       da = list_first_entry(&dsaddrs,
+                                             struct nfs4_pnfs_ds_addr,
+                                             da_node);
+                       list_del_init(&da->da_node);
+                       kfree(da->da_remotestr);
+                       kfree(da);
                }
        }
 
        __free_page(scratch);
        return dsaddr;
 
+out_err_drain_dsaddrs:
+       while (!list_empty(&dsaddrs)) {
+               da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
+                                     da_node);
+               list_del_init(&da->da_node);
+               kfree(da->da_remotestr);
+               kfree(da);
+       }
 out_err_free_deviceid:
        nfs4_fl_free_deviceid(dsaddr);
        /* stripe_indicies was part of dsaddr */