1 files changed, 840 insertions, 0 deletions

diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
new file mode 100644
index 000000000000..fdc4f6562bb7
--- /dev/null
+++ b/fs/nfs/pnfs_nfs.c
@@ -0,0 +1,840 @@
+/*
+ * Common NFS I/O  operations for the pnfs file based
+ * layout drivers.
+ *
+ * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
+ *
+ * Tom Haynes <loghyr@primarydata.com>
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/module.h>
+
+#include "nfs4session.h"
+#include "internal.h"
+#include "pnfs.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS
+
+void pnfs_generic_rw_release(void *data)
+{
+        struct nfs_pgio_header *hdr = data;
+
+        nfs_put_client(hdr->ds_clp);
+        hdr->mds_ops->rpc_release(data);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_rw_release);
+
+/* Fake up some data that will cause nfs_commit_release to retry the writes. */
+void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data)
+{
+        struct nfs_page *first = nfs_list_entry(data->pages.next);
+
+        data->task.tk_status = 0;
+        memcpy(&data->verf.verifier, &first->wb_verf,
+               sizeof(data->verf.verifier));
+        data->verf.verifier.data[0]++; /* ensure verifier mismatch */
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_prepare_to_resend_writes);
+
+void pnfs_generic_write_commit_done(struct rpc_task *task, void *data)
+{
+        struct nfs_commit_data *wdata = data;
+
+        /* Note this may cause RPC to be resent */
+        wdata->mds_ops->rpc_call_done(task, data);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_write_commit_done);
+
+void pnfs_generic_commit_release(void *calldata)
+{
+        struct nfs_commit_data *data = calldata;
+
+        data->completion_ops->completion(data);
+        pnfs_put_lseg(data->lseg);
+        nfs_put_client(data->ds_clp);
+        nfs_commitdata_release(data);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_commit_release);
+
+/* The generic layer is about to remove the req from the commit list.
+ * If this will make the bucket empty, it will need to put the lseg reference.
+ * Note this must be called holding the inode (/cinfo) lock
+ */
+void
+pnfs_generic_clear_request_commit(struct nfs_page *req,
+                                  struct nfs_commit_info *cinfo)
+{
+        struct pnfs_layout_segment *freeme = NULL;
+
+        if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
+                goto out;
+        cinfo->ds->nwritten--;
+        if (list_is_singular(&req->wb_list)) {
+                struct pnfs_commit_bucket *bucket;
+
+                bucket = list_first_entry(&req->wb_list,
+                                          struct pnfs_commit_bucket,
+                                          written);
+                freeme = bucket->wlseg;
+                bucket->wlseg = NULL;
+        }
+out:
+        nfs_request_remove_commit_list(req, cinfo);
+        pnfs_put_lseg_locked(freeme);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);
+
+static int
+pnfs_generic_transfer_commit_list(struct list_head *src, struct list_head *dst,
+                                  struct nfs_commit_info *cinfo, int max)
+{
+        struct nfs_page *req, *tmp;
+        int ret = 0;
+
+        list_for_each_entry_safe(req, tmp, src, wb_list) {
+                if (!nfs_lock_request(req))
+                        continue;
+                kref_get(&req->wb_kref);
+                if (cond_resched_lock(cinfo->lock))
+                        list_safe_reset_next(req, tmp, wb_list);
+                nfs_request_remove_commit_list(req, cinfo);
+                clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
+                nfs_list_add_request(req, dst);
+                ret++;
+                if ((ret == max) && !cinfo->dreq)
+                        break;
+        }
+        return ret;
+}
+
+static int
+pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
+                                 struct nfs_commit_info *cinfo,
+                                 int max)
+{
+        struct list_head *src = &bucket->written;
+        struct list_head *dst = &bucket->committing;
+        int ret;
+
+        lockdep_assert_held(cinfo->lock);
+        ret = pnfs_generic_transfer_commit_list(src, dst, cinfo, max);
+        if (ret) {
+                cinfo->ds->nwritten -= ret;
+                cinfo->ds->ncommitting += ret;
+                bucket->clseg = bucket->wlseg;
+                if (list_empty(src))
+                        bucket->wlseg = NULL;
+                else
+                        pnfs_get_lseg(bucket->clseg);
+        }
+        return ret;
+}
+
+/* Move reqs from written to committing lists, returning count
+ * of number moved.
+ */
+int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo,
+                                   int max)
+{
+        int i, rv = 0, cnt;
+
+        lockdep_assert_held(cinfo->lock);
+        for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
+                cnt = pnfs_generic_scan_ds_commit_list(&cinfo->ds->buckets[i],
+                                                       cinfo, max);
+                max -= cnt;
+                rv += cnt;
+        }
+        return rv;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_scan_commit_lists);
+
+/* Pull everything off the committing lists and dump into @dst.  */
+void pnfs_generic_recover_commit_reqs(struct list_head *dst,
+                                      struct nfs_commit_info *cinfo)
+{
+        struct pnfs_commit_bucket *b;
+        struct pnfs_layout_segment *freeme;
+        int i;
+
+        lockdep_assert_held(cinfo->lock);
+restart:
+        for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
+                if (pnfs_generic_transfer_commit_list(&b->written, dst,
+                                                      cinfo, 0)) {
+                        freeme = b->wlseg;
+                        b->wlseg = NULL;
+                        spin_unlock(cinfo->lock);
+                        pnfs_put_lseg(freeme);
+                        spin_lock(cinfo->lock);
+                        goto restart;
+                }
+        }
+        cinfo->ds->nwritten = 0;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
+
+static void pnfs_generic_retry_commit(struct nfs_commit_info *cinfo, int idx)
+{
+        struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+        struct pnfs_commit_bucket *bucket;
+        struct pnfs_layout_segment *freeme;
+        int i;
+
+        for (i = idx; i < fl_cinfo->nbuckets; i++) {
+                bucket = &fl_cinfo->buckets[i];
+                if (list_empty(&bucket->committing))
+                        continue;
+                nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo, i);
+                spin_lock(cinfo->lock);
+                freeme = bucket->clseg;
+                bucket->clseg = NULL;
+                spin_unlock(cinfo->lock);
+                pnfs_put_lseg(freeme);
+        }
+}
+
+static unsigned int
+pnfs_generic_alloc_ds_commits(struct nfs_commit_info *cinfo,
+                              struct list_head *list)
+{
+        struct pnfs_ds_commit_info *fl_cinfo;
+        struct pnfs_commit_bucket *bucket;
+        struct nfs_commit_data *data;
+        int i;
+        unsigned int nreq = 0;
+
+        fl_cinfo = cinfo->ds;
+        bucket = fl_cinfo->buckets;
+        for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
+                if (list_empty(&bucket->committing))
+                        continue;
+                data = nfs_commitdata_alloc();
+                if (!data)
+                        break;
+                data->ds_commit_index = i;
+                spin_lock(cinfo->lock);
+                data->lseg = bucket->clseg;
+                bucket->clseg = NULL;
+                spin_unlock(cinfo->lock);
+                list_add(&data->pages, list);
+                nreq++;
+        }
+
+        /* Clean up on error */
+        pnfs_generic_retry_commit(cinfo, i);
+        return nreq;
+}
+
+/* This follows nfs_commit_list pretty closely */
+int
+pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
+                             int how, struct nfs_commit_info *cinfo,
+                             int (*initiate_commit)(struct nfs_commit_data *data,
+                                                    int how))
+{
+        struct nfs_commit_data *data, *tmp;
+        LIST_HEAD(list);
+        unsigned int nreq = 0;
+
+        if (!list_empty(mds_pages)) {
+                data = nfs_commitdata_alloc();
+                if (data != NULL) {
+                        data->lseg = NULL;
+                        list_add(&data->pages, &list);
+                        nreq++;
+                } else {
+                        nfs_retry_commit(mds_pages, NULL, cinfo, 0);
+                        pnfs_generic_retry_commit(cinfo, 0);
+                        cinfo->completion_ops->error_cleanup(NFS_I(inode));
+                        return -ENOMEM;
+                }
+        }
+
+        nreq += pnfs_generic_alloc_ds_commits(cinfo, &list);
+
+        if (nreq == 0) {
+                cinfo->completion_ops->error_cleanup(NFS_I(inode));
+                goto out;
+        }
+
+        atomic_add(nreq, &cinfo->mds->rpcs_out);
+
+        list_for_each_entry_safe(data, tmp, &list, pages) {
+                list_del_init(&data->pages);
+                if (!data->lseg) {
+                        nfs_init_commit(data, mds_pages, NULL, cinfo);
+                        nfs_initiate_commit(NFS_CLIENT(inode), data,
+                                            NFS_PROTO(data->inode),
+                                            data->mds_ops, how, 0);
+                } else {
+                        struct pnfs_commit_bucket *buckets;
+
+                        buckets = cinfo->ds->buckets;
+                        nfs_init_commit(data,
+                                        &buckets[data->ds_commit_index].committing,
+                                        data->lseg,
+                                        cinfo);
+                        initiate_commit(data, how);
+                }
+        }
+out:
+        cinfo->ds->ncommitting = 0;
+        return PNFS_ATTEMPTED;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);
+
+/*
+ * Data server cache
+ *
+ * Data servers can be mapped to different device ids.
+ * nfs4_pnfs_ds reference counting
+ *   - set to 1 on allocation
+ *   - incremented when a device id maps a data server already in the cache.
+ *   - decremented when deviceid is removed from the cache.
+ */
+static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
+static LIST_HEAD(nfs4_data_server_cache);
+
+/* Debug routines */
+static void
+print_ds(struct nfs4_pnfs_ds *ds)
+{
+        if (ds == NULL) {
+                printk(KERN_WARNING "%s NULL device\n", __func__);
+                return;
+        }
+        printk(KERN_WARNING "        ds %s\n"
+                "        ref count %d\n"
+                "        client %p\n"
+                "        cl_exchange_flags %x\n",
+                ds->ds_remotestr,
+                atomic_read(&ds->ds_count), ds->ds_clp,
+                ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
+}
+
+static bool
+same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
+{
+        struct sockaddr_in *a, *b;
+        struct sockaddr_in6 *a6, *b6;
+
+        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_src_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;
+}
+
+static bool
+_same_data_server_addrs_locked(const struct list_head *dsaddrs1,
+                               const struct list_head *dsaddrs2)
+{
+        struct nfs4_pnfs_ds_addr *da1, *da2;
+
+        /* step through both lists, comparing as we go */
+        for (da1 = list_first_entry(dsaddrs1, typeof(*da1), da_node),
+             da2 = list_first_entry(dsaddrs2, typeof(*da2), da_node);
+             da1 != NULL && da2 != NULL;
+             da1 = list_entry(da1->da_node.next, typeof(*da1), da_node),
+             da2 = list_entry(da2->da_node.next, typeof(*da2), da_node)) {
+                if (!same_sockaddr((struct sockaddr *)&da1->da_addr,
+                                   (struct sockaddr *)&da2->da_addr))
+                        return false;
+        }
+        if (da1 == NULL && da2 == NULL)
+                return true;
+
+        return false;
+}
+
+/*
+ * Lookup DS by addresses.  nfs4_ds_cache_lock is held
+ */
+static struct nfs4_pnfs_ds *
+_data_server_lookup_locked(const struct list_head *dsaddrs)
+{
+        struct nfs4_pnfs_ds *ds;
+
+        list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
+                if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
+                        return ds;
+        return NULL;
+}
+
+static void destroy_ds(struct nfs4_pnfs_ds *ds)
+{
+        struct nfs4_pnfs_ds_addr *da;
+
+        dprintk("--> %s\n", __func__);
+        ifdebug(FACILITY)
+                print_ds(ds);
+
+        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);
+}
+
+void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
+{
+        if (atomic_dec_and_lock(&ds->ds_count,
+                                &nfs4_ds_cache_lock)) {
+                list_del_init(&ds->ds_node);
+                spin_unlock(&nfs4_ds_cache_lock);
+                destroy_ds(ds);
+        }
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);
+
+/*
+ * Create a string with a human readable address and port to avoid
+ * complicated setup around many dprinks.
+ */
+static char *
+nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
+{
+        struct nfs4_pnfs_ds_addr *da;
+        char *remotestr;
+        size_t len;
+        char *p;
+
+        len = 3;        /* '{', '}' and eol */
+        list_for_each_entry(da, dsaddrs, da_node) {
+                len += strlen(da->da_remotestr) + 1;    /* string plus comma */
+        }
+
+        remotestr = kzalloc(len, gfp_flags);
+        if (!remotestr)
+                return NULL;
+
+        p = remotestr;
+        *(p++) = '{';
+        len--;
+        list_for_each_entry(da, dsaddrs, da_node) {
+                size_t ll = strlen(da->da_remotestr);
+
+                if (ll > len)
+                        goto out_err;
+
+                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;
+}
+
+/*
+ * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
+ * uncached and return cached struct nfs4_pnfs_ds.
+ */
+struct nfs4_pnfs_ds *
+nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
+{
+        struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
+        char *remotestr;
+
+        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(dsaddrs, gfp_flags);
+
+        spin_lock(&nfs4_ds_cache_lock);
+        tmp_ds = _data_server_lookup_locked(dsaddrs);
+        if (tmp_ds == NULL) {
+                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);
+                ds->ds_clp = NULL;
+                list_add(&ds->ds_node, &nfs4_data_server_cache);
+                dprintk("%s add new data server %s\n", __func__,
+                        ds->ds_remotestr);
+        } else {
+                kfree(remotestr);
+                kfree(ds);
+                atomic_inc(&tmp_ds->ds_count);
+                dprintk("%s data server %s found, inc'ed ds_count to %d\n",
+                        __func__, tmp_ds->ds_remotestr,
+                        atomic_read(&tmp_ds->ds_count));
+                ds = tmp_ds;
+        }
+        spin_unlock(&nfs4_ds_cache_lock);
+out:
+        return ds;
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);
+
+static void nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
+{
+        might_sleep();
+        wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING,
+                        TASK_KILLABLE);
+}
+
+static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
+{
+        smp_mb__before_atomic();
+        clear_bit(NFS4DS_CONNECTING, &ds->ds_state);
+        smp_mb__after_atomic();
+        wake_up_bit(&ds->ds_state, NFS4DS_CONNECTING);
+}
+
+static struct nfs_client *(*get_v3_ds_connect)(
+                        struct nfs_client *mds_clp,
+                        const struct sockaddr *ds_addr,
+                        int ds_addrlen,
+                        int ds_proto,
+                        unsigned int ds_timeo,
+                        unsigned int ds_retrans,
+                        rpc_authflavor_t au_flavor);
+
+static bool load_v3_ds_connect(void)
+{
+        if (!get_v3_ds_connect) {
+                get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
+                WARN_ON_ONCE(!get_v3_ds_connect);
+        }
+
+        return(get_v3_ds_connect != NULL);
+}
+
+void __exit nfs4_pnfs_v3_ds_connect_unload(void)
+{
+        if (get_v3_ds_connect) {
+                symbol_put(nfs3_set_ds_client);
+                get_v3_ds_connect = NULL;
+        }
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_v3_ds_connect_unload);
+
+static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
+                                 struct nfs4_pnfs_ds *ds,
+                                 unsigned int timeo,
+                                 unsigned int retrans,
+                                 rpc_authflavor_t au_flavor)
+{
+        struct nfs_client *clp = ERR_PTR(-EIO);
+        struct nfs4_pnfs_ds_addr *da;
+        int status = 0;
+
+        dprintk("--> %s DS %s au_flavor %d\n", __func__,
+                ds->ds_remotestr, au_flavor);
+
+        if (!load_v3_ds_connect())
+                goto out;
+
+        list_for_each_entry(da, &ds->ds_addrs, da_node) {
+                dprintk("%s: DS %s: trying address %s\n",
+                        __func__, ds->ds_remotestr, da->da_remotestr);
+
+                clp = get_v3_ds_connect(mds_srv->nfs_client,
+                                        (struct sockaddr *)&da->da_addr,
+                                        da->da_addrlen, IPPROTO_TCP,
+                                        timeo, retrans, au_flavor);
+                if (!IS_ERR(clp))
+                        break;
+        }
+
+        if (IS_ERR(clp)) {
+                status = PTR_ERR(clp);
+                goto out;
+        }
+
+        smp_wmb();
+        ds->ds_clp = clp;
+        dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
+out:
+        return status;
+}
+
+static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
+                                 struct nfs4_pnfs_ds *ds,
+                                 unsigned int timeo,
+                                 unsigned int retrans,
+                                 u32 minor_version,
+                                 rpc_authflavor_t au_flavor)
+{
+        struct nfs_client *clp = ERR_PTR(-EIO);
+        struct nfs4_pnfs_ds_addr *da;
+        int status = 0;
+
+        dprintk("--> %s DS %s au_flavor %d\n", __func__, ds->ds_remotestr,
+                au_flavor);
+
+        list_for_each_entry(da, &ds->ds_addrs, da_node) {
+                dprintk("%s: DS %s: trying address %s\n",
+                        __func__, ds->ds_remotestr, da->da_remotestr);
+
+                clp = nfs4_set_ds_client(mds_srv->nfs_client,
+                                        (struct sockaddr *)&da->da_addr,
+                                        da->da_addrlen, IPPROTO_TCP,
+                                        timeo, retrans, minor_version,
+                                        au_flavor);
+                if (!IS_ERR(clp))
+                        break;
+        }
+
+        if (IS_ERR(clp)) {
+                status = PTR_ERR(clp);
+                goto out;
+        }
+
+        status = nfs4_init_ds_session(clp, mds_srv->nfs_client->cl_lease_time);
+        if (status)
+                goto out_put;
+
+        smp_wmb();
+        ds->ds_clp = clp;
+        dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
+out:
+        return status;
+out_put:
+        nfs_put_client(clp);
+        goto out;
+}
+
+/*
+ * Create an rpc connection to the nfs4_pnfs_ds data server.
+ * Currently only supports IPv4 and IPv6 addresses.
+ * If connection fails, make devid unavailable.
+ */
+void nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
+                          struct nfs4_deviceid_node *devid, unsigned int timeo,
+                          unsigned int retrans, u32 version,
+                          u32 minor_version, rpc_authflavor_t au_flavor)
+{
+        if (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) == 0) {
+                int err = 0;
+
+                if (version == 3) {
+                        err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo,
+                                                       retrans, au_flavor);
+                } else if (version == 4) {
+                        err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo,
+                                                       retrans, minor_version,
+                                                       au_flavor);
+                } else {
+                        dprintk("%s: unsupported DS version %d\n", __func__,
+                                version);
+                        err = -EPROTONOSUPPORT;
+                }
+
+                if (err)
+                        nfs4_mark_deviceid_unavailable(devid);
+                nfs4_clear_ds_conn_bit(ds);
+        } else {
+                nfs4_wait_ds_connect(ds);
+        }
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);
+
+/*
+ * Currently only supports ipv4, ipv6 and one multi-path address.
+ */
+struct nfs4_pnfs_ds_addr *
+nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
+{
+        struct nfs4_pnfs_ds_addr *da = NULL;
+        char *buf, *portstr;
+        __be16 port;
+        int nlen, rlen;
+        int tmp[2];
+        __be32 *p;
+        char *netid, *match_netid;
+        size_t len, match_netid_len;
+        char *startsep = "";
+        char *endsep = "";
+
+
+        /* r_netid */
+        p = xdr_inline_decode(xdr, 4);
+        if (unlikely(!p))
+                goto out_err;
+        nlen = be32_to_cpup(p++);
+
+        p = xdr_inline_decode(xdr, nlen);
+        if (unlikely(!p))
+                goto out_err;
+
+        netid = kmalloc(nlen+1, gfp_flags);
+        if (unlikely(!netid))
+                goto out_err;
+
+        netid[nlen] = '\0';
+        memcpy(netid, p, nlen);
+
+        /* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
+        p = xdr_inline_decode(xdr, 4);
+        if (unlikely(!p))
+                goto out_free_netid;
+        rlen = be32_to_cpup(p);
+
+        p = xdr_inline_decode(xdr, rlen);
+        if (unlikely(!p))
+                goto out_free_netid;
+
+        /* port is ".ABC.DEF", 8 chars max */
+        if (rlen > INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN + 8) {
+                dprintk("%s: Invalid address, length %d\n", __func__,
+                        rlen);
+                goto out_free_netid;
+        }
+        buf = kmalloc(rlen + 1, gfp_flags);
+        if (!buf) {
+                dprintk("%s: Not enough memory\n", __func__);
+                goto out_free_netid;
+        }
+        buf[rlen] = '\0';
+        memcpy(buf, p, rlen);
+
+        /* replace port '.' with '-' */
+        portstr = strrchr(buf, '.');
+        if (!portstr) {
+                dprintk("%s: Failed finding expected dot in port\n",
+                        __func__);
+                goto out_free_buf;
+        }
+        *portstr = '-';
+
+        /* find '.' between address and port */
+        portstr = strrchr(buf, '.');
+        if (!portstr) {
+                dprintk("%s: Failed finding expected dot between address and "
+                        "port\n", __func__);
+                goto out_free_buf;
+        }
+        *portstr = '\0';
+
+        da = kzalloc(sizeof(*da), gfp_flags);
+        if (unlikely(!da))
+                goto out_free_buf;
+
+        INIT_LIST_HEAD(&da->da_node);
+
+        if (!rpc_pton(net, 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 (da->da_addr.ss_family) {
+        case AF_INET:
+                ((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 *)&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__, 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_da;
+        }
+
+        /* 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 NULL;
+}
+EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);