nfsd: add a "GetVersion" upcall for nfsdcld

Add a "GetVersion" upcall to allow nfsd to determine the maximum upcall
version that the nfsdcld userspace daemon supports.  If the daemon
responds with -EOPNOTSUPP, then we know it only supports v1.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 8767955..58a6133 100644 (file)
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -59,8 +59,12 @@ struct nfsd4_client_tracking_ops {
        void (*remove)(struct nfs4_client *);
        int (*check)(struct nfs4_client *);
        void (*grace_done)(struct nfsd_net *);
+       uint8_t version;
+       size_t msglen;
 };
 
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops;
+
 /* Globals */
 static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
 
@@ -718,6 +722,8 @@ static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
        .remove         = nfsd4_remove_clid_dir,
        .check          = nfsd4_check_legacy_client,
        .grace_done     = nfsd4_recdir_purge_old,
+       .version        = 1,
+       .msglen         = 0,
 };
 
 /* Globals */
@@ -737,19 +743,24 @@ struct cld_upcall {
        struct list_head         cu_list;
        struct cld_net          *cu_net;
        struct completion        cu_done;
-       struct cld_msg           cu_msg;
+       union {
+               struct cld_msg_hdr       cu_hdr;
+               struct cld_msg           cu_msg;
+       } cu_u;
 };
 
 static int
-__cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
+__cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg)
 {
        int ret;
        struct rpc_pipe_msg msg;
-       struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_msg);
+       struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
+       struct nfsd_net *nn = net_generic(pipe->dentry->d_sb->s_fs_info,
+                                         nfsd_net_id);
 
        memset(&msg, 0, sizeof(msg));
        msg.data = cmsg;
-       msg.len = sizeof(*cmsg);
+       msg.len = nn->client_tracking_ops->msglen;
 
        ret = rpc_queue_upcall(pipe, &msg);
        if (ret < 0) {
@@ -765,7 +776,7 @@ out:
 }
 
 static int
-cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
+cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg)
 {
        int ret;
 
@@ -809,7 +820,7 @@ __cld_pipe_inprogress_downcall(const struct cld_msg __user *cmsg,
                        kfree(name.data);
                        return -EFAULT;
                }
-               return sizeof(*cmsg);
+               return nn->client_tracking_ops->msglen;
        }
        return -EFAULT;
 }
@@ -818,6 +829,7 @@ static ssize_t
 cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 {
        struct cld_upcall *tmp, *cup;
+       struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
        struct cld_msg __user *cmsg = (struct cld_msg __user *)src;
        uint32_t xid;
        struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
@@ -825,14 +837,14 @@ cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
        struct cld_net *cn = nn->cld_net;
        int16_t status;
 
-       if (mlen != sizeof(*cmsg)) {
+       if (mlen != nn->client_tracking_ops->msglen) {
                dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
-                       sizeof(*cmsg));
+                       nn->client_tracking_ops->msglen);
                return -EINVAL;
        }
 
        /* copy just the xid so we can try to find that */
-       if (copy_from_user(&xid, &cmsg->cm_xid, sizeof(xid)) != 0) {
+       if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
                dprintk("%s: error when copying xid from userspace", __func__);
                return -EFAULT;
        }
@@ -842,7 +854,7 @@ cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
         * list (for -EINPROGRESS, we just want to make sure the xid is
         * valid, not remove the upcall from the list)
         */
-       if (get_user(status, &cmsg->cm_status)) {
+       if (get_user(status, &hdr->cm_status)) {
                dprintk("%s: error when copying status from userspace", __func__);
                return -EFAULT;
        }
@@ -851,7 +863,7 @@ cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
        cup = NULL;
        spin_lock(&cn->cn_lock);
        list_for_each_entry(tmp, &cn->cn_list, cu_list) {
-               if (get_unaligned(&tmp->cu_msg.cm_xid) == xid) {
+               if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
                        cup = tmp;
                        if (status != -EINPROGRESS)
                                list_del_init(&cup->cu_list);
@@ -869,7 +881,7 @@ cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
        if (status == -EINPROGRESS)
                return __cld_pipe_inprogress_downcall(cmsg, nn);
 
-       if (copy_from_user(&cup->cu_msg, src, mlen) != 0)
+       if (copy_from_user(&cup->cu_u.cu_msg, src, mlen) != 0)
                return -EFAULT;
 
        complete(&cup->cu_done);
@@ -881,7 +893,7 @@ cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 {
        struct cld_msg *cmsg = msg->data;
        struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
-                                                cu_msg);
+                                                cu_u.cu_msg);
 
        /* errno >= 0 means we got a downcall */
        if (msg->errno >= 0)
@@ -1012,9 +1024,10 @@ nfsd4_remove_cld_pipe(struct net *net)
 }
 
 static struct cld_upcall *
-alloc_cld_upcall(struct cld_net *cn)
+alloc_cld_upcall(struct nfsd_net *nn)
 {
        struct cld_upcall *new, *tmp;
+       struct cld_net *cn = nn->cld_net;
 
        new = kzalloc(sizeof(*new), GFP_KERNEL);
        if (!new)
@@ -1024,20 +1037,20 @@ alloc_cld_upcall(struct cld_net *cn)
 restart_search:
        spin_lock(&cn->cn_lock);
        list_for_each_entry(tmp, &cn->cn_list, cu_list) {
-               if (tmp->cu_msg.cm_xid == cn->cn_xid) {
+               if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
                        cn->cn_xid++;
                        spin_unlock(&cn->cn_lock);
                        goto restart_search;
                }
        }
        init_completion(&new->cu_done);
-       new->cu_msg.cm_vers = CLD_UPCALL_VERSION;
-       put_unaligned(cn->cn_xid++, &new->cu_msg.cm_xid);
+       new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
+       put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
        new->cu_net = cn;
        list_add(&new->cu_list, &cn->cn_list);
        spin_unlock(&cn->cn_lock);
 
-       dprintk("%s: allocated xid %u\n", __func__, new->cu_msg.cm_xid);
+       dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
 
        return new;
 }
@@ -1066,20 +1079,20 @@ nfsd4_cld_create(struct nfs4_client *clp)
        if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
                return;
 
-       cup = alloc_cld_upcall(cn);
+       cup = alloc_cld_upcall(nn);
        if (!cup) {
                ret = -ENOMEM;
                goto out_err;
        }
 
-       cup->cu_msg.cm_cmd = Cld_Create;
-       cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
-       memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+       cup->cu_u.cu_msg.cm_cmd = Cld_Create;
+       cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+       memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
                        clp->cl_name.len);
 
-       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
+       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
        if (!ret) {
-               ret = cup->cu_msg.cm_status;
+               ret = cup->cu_u.cu_msg.cm_status;
                set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
        }
 
@@ -1103,20 +1116,20 @@ nfsd4_cld_remove(struct nfs4_client *clp)
        if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
                return;
 
-       cup = alloc_cld_upcall(cn);
+       cup = alloc_cld_upcall(nn);
        if (!cup) {
                ret = -ENOMEM;
                goto out_err;
        }
 
-       cup->cu_msg.cm_cmd = Cld_Remove;
-       cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
-       memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+       cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
+       cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+       memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
                        clp->cl_name.len);
 
-       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
+       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
        if (!ret) {
-               ret = cup->cu_msg.cm_status;
+               ret = cup->cu_u.cu_msg.cm_status;
                clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
        }
 
@@ -1145,21 +1158,21 @@ nfsd4_cld_check_v0(struct nfs4_client *clp)
        if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
                return 0;
 
-       cup = alloc_cld_upcall(cn);
+       cup = alloc_cld_upcall(nn);
        if (!cup) {
                printk(KERN_ERR "NFSD: Unable to check client record on "
                                "stable storage: %d\n", -ENOMEM);
                return -ENOMEM;
        }
 
-       cup->cu_msg.cm_cmd = Cld_Check;
-       cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
-       memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+       cup->cu_u.cu_msg.cm_cmd = Cld_Check;
+       cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+       memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
                        clp->cl_name.len);
 
-       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
+       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
        if (!ret) {
-               ret = cup->cu_msg.cm_status;
+               ret = cup->cu_u.cu_msg.cm_status;
                set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
        }
 
@@ -1223,16 +1236,16 @@ nfsd4_cld_grace_start(struct nfsd_net *nn)
        struct cld_upcall *cup;
        struct cld_net *cn = nn->cld_net;
 
-       cup = alloc_cld_upcall(cn);
+       cup = alloc_cld_upcall(nn);
        if (!cup) {
                ret = -ENOMEM;
                goto out_err;
        }
 
-       cup->cu_msg.cm_cmd = Cld_GraceStart;
-       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
+       cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
+       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
        if (!ret)
-               ret = cup->cu_msg.cm_status;
+               ret = cup->cu_u.cu_msg.cm_status;
 
        free_cld_upcall(cup);
 out_err:
@@ -1250,17 +1263,17 @@ nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
        struct cld_upcall *cup;
        struct cld_net *cn = nn->cld_net;
 
-       cup = alloc_cld_upcall(cn);
+       cup = alloc_cld_upcall(nn);
        if (!cup) {
                ret = -ENOMEM;
                goto out_err;
        }
 
-       cup->cu_msg.cm_cmd = Cld_GraceDone;
-       cup->cu_msg.cm_u.cm_gracetime = (int64_t)nn->boot_time;
-       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
+       cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
+       cup->cu_u.cu_msg.cm_u.cm_gracetime = (int64_t)nn->boot_time;
+       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
        if (!ret)
-               ret = cup->cu_msg.cm_status;
+               ret = cup->cu_u.cu_msg.cm_status;
 
        free_cld_upcall(cup);
 out_err:
@@ -1279,16 +1292,16 @@ nfsd4_cld_grace_done(struct nfsd_net *nn)
        struct cld_upcall *cup;
        struct cld_net *cn = nn->cld_net;
 
-       cup = alloc_cld_upcall(cn);
+       cup = alloc_cld_upcall(nn);
        if (!cup) {
                ret = -ENOMEM;
                goto out_err;
        }
 
-       cup->cu_msg.cm_cmd = Cld_GraceDone;
-       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
+       cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
+       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
        if (!ret)
-               ret = cup->cu_msg.cm_status;
+               ret = cup->cu_u.cu_msg.cm_status;
 
        free_cld_upcall(cup);
 out_err:
@@ -1336,6 +1349,50 @@ cld_running(struct nfsd_net *nn)
        return pipe->nreaders || pipe->nwriters;
 }
 
+static int
+nfsd4_cld_get_version(struct nfsd_net *nn)
+{
+       int ret = 0;
+       struct cld_upcall *cup;
+       struct cld_net *cn = nn->cld_net;
+       uint8_t version;
+
+       cup = alloc_cld_upcall(nn);
+       if (!cup) {
+               ret = -ENOMEM;
+               goto out_err;
+       }
+       cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
+       ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg);
+       if (!ret) {
+               ret = cup->cu_u.cu_msg.cm_status;
+               if (ret)
+                       goto out_free;
+               version = cup->cu_u.cu_msg.cm_u.cm_version;
+               dprintk("%s: userspace returned version %u\n",
+                               __func__, version);
+               if (version < 1)
+                       version = 1;
+               else if (version > CLD_UPCALL_VERSION)
+                       version = CLD_UPCALL_VERSION;
+
+               switch (version) {
+               case 1:
+                       nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
+                       break;
+               default:
+                       break;
+               }
+       }
+out_free:
+       free_cld_upcall(cup);
+out_err:
+       if (ret)
+               dprintk("%s: Unable to get version from userspace: %d\n",
+                       __func__, ret);
+       return ret;
+}
+
 static int
 nfsd4_cld_tracking_init(struct net *net)
 {
@@ -1368,10 +1425,14 @@ nfsd4_cld_tracking_init(struct net *net)
                goto err_remove;
        }
 
+       status = nfsd4_cld_get_version(nn);
+       if (status == -EOPNOTSUPP)
+               pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
+
        status = nfsd4_cld_grace_start(nn);
        if (status) {
                if (status == -EOPNOTSUPP)
-                       printk(KERN_WARNING "NFSD: Please upgrade nfsdcld.\n");
+                       pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
                nfs4_release_reclaim(nn);
                goto err_remove;
        } else
@@ -1403,6 +1464,8 @@ static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
        .remove         = nfsd4_cld_remove,
        .check          = nfsd4_cld_check_v0,
        .grace_done     = nfsd4_cld_grace_done_v0,
+       .version        = 1,
+       .msglen         = sizeof(struct cld_msg),
 };
 
 /* For newer nfsdcld's */
@@ -1413,6 +1476,8 @@ static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
        .remove         = nfsd4_cld_remove,
        .check          = nfsd4_cld_check,
        .grace_done     = nfsd4_cld_grace_done,
+       .version        = 1,
+       .msglen         = sizeof(struct cld_msg),
 };
 
 /* upcall via usermodehelper */
@@ -1760,6 +1825,8 @@ static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
        .remove         = nfsd4_umh_cltrack_remove,
        .check          = nfsd4_umh_cltrack_check,
        .grace_done     = nfsd4_umh_cltrack_grace_done,
+       .version        = 1,
+       .msglen         = 0,
 };
 
 int

diff --git a/include/uapi/linux/nfsd/cld.h b/include/uapi/linux/nfsd/cld.h
index b1e9de4..c5aad16 100644 (file)
--- a/include/uapi/linux/nfsd/cld.h
+++ b/include/uapi/linux/nfsd/cld.h
@@ -36,7 +36,8 @@ enum cld_command {
        Cld_Remove,             /* remove record of this cm_id */
        Cld_Check,              /* is this cm_id allowed? */
        Cld_GraceDone,          /* grace period is complete */
-       Cld_GraceStart,
+       Cld_GraceStart,         /* grace start (upload client records) */
+       Cld_GetVersion,         /* query max supported upcall version */
 };
 
 /* representation of long-form NFSv4 client ID */
@@ -54,7 +55,15 @@ struct cld_msg {
        union {
                __s64           cm_gracetime;   /* grace period start time */
                struct cld_name cm_name;
+               __u8            cm_version;     /* for getting max version */
        } __attribute__((packed)) cm_u;
 } __attribute__((packed));
 
+struct cld_msg_hdr {
+       __u8            cm_vers;                /* upcall version */
+       __u8            cm_cmd;                 /* upcall command */
+       __s16           cm_status;              /* return code */
+       __u32           cm_xid;                 /* transaction id */
+} __attribute__((packed));
+
 #endif /* !_NFSD_CLD_H */