Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / 9p / client.c
diff --git a/kernel/net/9p/client.c b/kernel/net/9p/client.c
new file mode 100644 (file)
index 0000000..6f4c4c8
--- /dev/null
@@ -0,0 +1,2261 @@
+/*
+ * net/9p/clnt.c
+ *
+ * 9P Client
+ *
+ *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/idr.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+#include <net/9p/9p.h>
+#include <linux/parser.h>
+#include <net/9p/client.h>
+#include <net/9p/transport.h>
+#include "protocol.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/9p.h>
+
+/*
+  * Client Option Parsing (code inspired by NFS code)
+  *  - a little lazy - parse all client options
+  */
+
+enum {
+       Opt_msize,
+       Opt_trans,
+       Opt_legacy,
+       Opt_version,
+       Opt_err,
+};
+
+static const match_table_t tokens = {
+       {Opt_msize, "msize=%u"},
+       {Opt_legacy, "noextend"},
+       {Opt_trans, "trans=%s"},
+       {Opt_version, "version=%s"},
+       {Opt_err, NULL},
+};
+
+inline int p9_is_proto_dotl(struct p9_client *clnt)
+{
+       return clnt->proto_version == p9_proto_2000L;
+}
+EXPORT_SYMBOL(p9_is_proto_dotl);
+
+inline int p9_is_proto_dotu(struct p9_client *clnt)
+{
+       return clnt->proto_version == p9_proto_2000u;
+}
+EXPORT_SYMBOL(p9_is_proto_dotu);
+
+/*
+ * Some error codes are taken directly from the server replies,
+ * make sure they are valid.
+ */
+static int safe_errno(int err)
+{
+       if ((err > 0) || (err < -MAX_ERRNO)) {
+               p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
+               return -EPROTO;
+       }
+       return err;
+}
+
+
+/* Interpret mount option for protocol version */
+static int get_protocol_version(char *s)
+{
+       int version = -EINVAL;
+
+       if (!strcmp(s, "9p2000")) {
+               version = p9_proto_legacy;
+               p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
+       } else if (!strcmp(s, "9p2000.u")) {
+               version = p9_proto_2000u;
+               p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
+       } else if (!strcmp(s, "9p2000.L")) {
+               version = p9_proto_2000L;
+               p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
+       } else
+               pr_info("Unknown protocol version %s\n", s);
+
+       return version;
+}
+
+/**
+ * parse_options - parse mount options into client structure
+ * @opts: options string passed from mount
+ * @clnt: existing v9fs client information
+ *
+ * Return 0 upon success, -ERRNO upon failure
+ */
+
+static int parse_opts(char *opts, struct p9_client *clnt)
+{
+       char *options, *tmp_options;
+       char *p;
+       substring_t args[MAX_OPT_ARGS];
+       int option;
+       char *s;
+       int ret = 0;
+
+       clnt->proto_version = p9_proto_2000L;
+       clnt->msize = 8192;
+
+       if (!opts)
+               return 0;
+
+       tmp_options = kstrdup(opts, GFP_KERNEL);
+       if (!tmp_options) {
+               p9_debug(P9_DEBUG_ERROR,
+                        "failed to allocate copy of option string\n");
+               return -ENOMEM;
+       }
+       options = tmp_options;
+
+       while ((p = strsep(&options, ",")) != NULL) {
+               int token, r;
+               if (!*p)
+                       continue;
+               token = match_token(p, tokens, args);
+               switch (token) {
+               case Opt_msize:
+                       r = match_int(&args[0], &option);
+                       if (r < 0) {
+                               p9_debug(P9_DEBUG_ERROR,
+                                        "integer field, but no integer?\n");
+                               ret = r;
+                               continue;
+                       }
+                       clnt->msize = option;
+                       break;
+               case Opt_trans:
+                       s = match_strdup(&args[0]);
+                       if (!s) {
+                               ret = -ENOMEM;
+                               p9_debug(P9_DEBUG_ERROR,
+                                        "problem allocating copy of trans arg\n");
+                               goto free_and_return;
+                        }
+                       clnt->trans_mod = v9fs_get_trans_by_name(s);
+                       if (clnt->trans_mod == NULL) {
+                               pr_info("Could not find request transport: %s\n",
+                                       s);
+                               ret = -EINVAL;
+                               kfree(s);
+                               goto free_and_return;
+                       }
+                       kfree(s);
+                       break;
+               case Opt_legacy:
+                       clnt->proto_version = p9_proto_legacy;
+                       break;
+               case Opt_version:
+                       s = match_strdup(&args[0]);
+                       if (!s) {
+                               ret = -ENOMEM;
+                               p9_debug(P9_DEBUG_ERROR,
+                                        "problem allocating copy of version arg\n");
+                               goto free_and_return;
+                       }
+                       ret = get_protocol_version(s);
+                       if (ret == -EINVAL) {
+                               kfree(s);
+                               goto free_and_return;
+                       }
+                       kfree(s);
+                       clnt->proto_version = ret;
+                       break;
+               default:
+                       continue;
+               }
+       }
+
+free_and_return:
+       kfree(tmp_options);
+       return ret;
+}
+
+static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
+{
+       struct p9_fcall *fc;
+       fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
+       if (!fc)
+               return NULL;
+       fc->capacity = alloc_msize;
+       fc->sdata = (char *) fc + sizeof(struct p9_fcall);
+       return fc;
+}
+
+/**
+ * p9_tag_alloc - lookup/allocate a request by tag
+ * @c: client session to lookup tag within
+ * @tag: numeric id for transaction
+ *
+ * this is a simple array lookup, but will grow the
+ * request_slots as necessary to accommodate transaction
+ * ids which did not previously have a slot.
+ *
+ * this code relies on the client spinlock to manage locks, its
+ * possible we should switch to something else, but I'd rather
+ * stick with something low-overhead for the common case.
+ *
+ */
+
+static struct p9_req_t *
+p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
+{
+       unsigned long flags;
+       int row, col;
+       struct p9_req_t *req;
+       int alloc_msize = min(c->msize, max_size);
+
+       /* This looks up the original request by tag so we know which
+        * buffer to read the data into */
+       tag++;
+
+       if (tag >= c->max_tag) {
+               spin_lock_irqsave(&c->lock, flags);
+               /* check again since original check was outside of lock */
+               while (tag >= c->max_tag) {
+                       row = (tag / P9_ROW_MAXTAG);
+                       c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
+                                       sizeof(struct p9_req_t), GFP_ATOMIC);
+
+                       if (!c->reqs[row]) {
+                               pr_err("Couldn't grow tag array\n");
+                               spin_unlock_irqrestore(&c->lock, flags);
+                               return ERR_PTR(-ENOMEM);
+                       }
+                       for (col = 0; col < P9_ROW_MAXTAG; col++) {
+                               c->reqs[row][col].status = REQ_STATUS_IDLE;
+                               c->reqs[row][col].tc = NULL;
+                       }
+                       c->max_tag += P9_ROW_MAXTAG;
+               }
+               spin_unlock_irqrestore(&c->lock, flags);
+       }
+       row = tag / P9_ROW_MAXTAG;
+       col = tag % P9_ROW_MAXTAG;
+
+       req = &c->reqs[row][col];
+       if (!req->wq) {
+               req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
+               if (!req->wq)
+                       goto grow_failed;
+               init_waitqueue_head(req->wq);
+       }
+
+       if (!req->tc)
+               req->tc = p9_fcall_alloc(alloc_msize);
+       if (!req->rc)
+               req->rc = p9_fcall_alloc(alloc_msize);
+       if (!req->tc || !req->rc)
+               goto grow_failed;
+
+       p9pdu_reset(req->tc);
+       p9pdu_reset(req->rc);
+
+       req->tc->tag = tag-1;
+       req->status = REQ_STATUS_ALLOC;
+
+       return req;
+
+grow_failed:
+       pr_err("Couldn't grow tag array\n");
+       kfree(req->tc);
+       kfree(req->rc);
+       kfree(req->wq);
+       req->tc = req->rc = NULL;
+       req->wq = NULL;
+       return ERR_PTR(-ENOMEM);
+}
+
+/**
+ * p9_tag_lookup - lookup a request by tag
+ * @c: client session to lookup tag within
+ * @tag: numeric id for transaction
+ *
+ */
+
+struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
+{
+       int row, col;
+
+       /* This looks up the original request by tag so we know which
+        * buffer to read the data into */
+       tag++;
+
+       if(tag >= c->max_tag) 
+               return NULL;
+
+       row = tag / P9_ROW_MAXTAG;
+       col = tag % P9_ROW_MAXTAG;
+
+       return &c->reqs[row][col];
+}
+EXPORT_SYMBOL(p9_tag_lookup);
+
+/**
+ * p9_tag_init - setup tags structure and contents
+ * @c:  v9fs client struct
+ *
+ * This initializes the tags structure for each client instance.
+ *
+ */
+
+static int p9_tag_init(struct p9_client *c)
+{
+       int err = 0;
+
+       c->tagpool = p9_idpool_create();
+       if (IS_ERR(c->tagpool)) {
+               err = PTR_ERR(c->tagpool);
+               goto error;
+       }
+       err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
+       if (err < 0) {
+               p9_idpool_destroy(c->tagpool);
+               goto error;
+       }
+       c->max_tag = 0;
+error:
+       return err;
+}
+
+/**
+ * p9_tag_cleanup - cleans up tags structure and reclaims resources
+ * @c:  v9fs client struct
+ *
+ * This frees resources associated with the tags structure
+ *
+ */
+static void p9_tag_cleanup(struct p9_client *c)
+{
+       int row, col;
+
+       /* check to insure all requests are idle */
+       for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
+               for (col = 0; col < P9_ROW_MAXTAG; col++) {
+                       if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
+                               p9_debug(P9_DEBUG_MUX,
+                                        "Attempting to cleanup non-free tag %d,%d\n",
+                                        row, col);
+                               /* TODO: delay execution of cleanup */
+                               return;
+                       }
+               }
+       }
+
+       if (c->tagpool) {
+               p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
+               p9_idpool_destroy(c->tagpool);
+       }
+
+       /* free requests associated with tags */
+       for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
+               for (col = 0; col < P9_ROW_MAXTAG; col++) {
+                       kfree(c->reqs[row][col].wq);
+                       kfree(c->reqs[row][col].tc);
+                       kfree(c->reqs[row][col].rc);
+               }
+               kfree(c->reqs[row]);
+       }
+       c->max_tag = 0;
+}
+
+/**
+ * p9_free_req - free a request and clean-up as necessary
+ * c: client state
+ * r: request to release
+ *
+ */
+
+static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
+{
+       int tag = r->tc->tag;
+       p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
+
+       r->status = REQ_STATUS_IDLE;
+       if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
+               p9_idpool_put(tag, c->tagpool);
+}
+
+/**
+ * p9_client_cb - call back from transport to client
+ * c: client state
+ * req: request received
+ *
+ */
+void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
+{
+       p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
+
+       /*
+        * This barrier is needed to make sure any change made to req before
+        * the other thread wakes up will indeed be seen by the waiting side.
+        */
+       smp_wmb();
+       req->status = status;
+
+       wake_up(req->wq);
+       p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
+}
+EXPORT_SYMBOL(p9_client_cb);
+
+/**
+ * p9_parse_header - parse header arguments out of a packet
+ * @pdu: packet to parse
+ * @size: size of packet
+ * @type: type of request
+ * @tag: tag of packet
+ * @rewind: set if we need to rewind offset afterwards
+ */
+
+int
+p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
+                                                               int rewind)
+{
+       int8_t r_type;
+       int16_t r_tag;
+       int32_t r_size;
+       int offset = pdu->offset;
+       int err;
+
+       pdu->offset = 0;
+       if (pdu->size == 0)
+               pdu->size = 7;
+
+       err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
+       if (err)
+               goto rewind_and_exit;
+
+       pdu->size = r_size;
+       pdu->id = r_type;
+       pdu->tag = r_tag;
+
+       p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
+                pdu->size, pdu->id, pdu->tag);
+
+       if (type)
+               *type = r_type;
+       if (tag)
+               *tag = r_tag;
+       if (size)
+               *size = r_size;
+
+
+rewind_and_exit:
+       if (rewind)
+               pdu->offset = offset;
+       return err;
+}
+EXPORT_SYMBOL(p9_parse_header);
+
+/**
+ * p9_check_errors - check 9p packet for error return and process it
+ * @c: current client instance
+ * @req: request to parse and check for error conditions
+ *
+ * returns error code if one is discovered, otherwise returns 0
+ *
+ * this will have to be more complicated if we have multiple
+ * error packet types
+ */
+
+static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
+{
+       int8_t type;
+       int err;
+       int ecode;
+
+       err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
+       /*
+        * dump the response from server
+        * This should be after check errors which poplulate pdu_fcall.
+        */
+       trace_9p_protocol_dump(c, req->rc);
+       if (err) {
+               p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
+               return err;
+       }
+       if (type != P9_RERROR && type != P9_RLERROR)
+               return 0;
+
+       if (!p9_is_proto_dotl(c)) {
+               char *ename;
+               err = p9pdu_readf(req->rc, c->proto_version, "s?d",
+                                 &ename, &ecode);
+               if (err)
+                       goto out_err;
+
+               if (p9_is_proto_dotu(c))
+                       err = -ecode;
+
+               if (!err || !IS_ERR_VALUE(err)) {
+                       err = p9_errstr2errno(ename, strlen(ename));
+
+                       p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
+                                -ecode, ename);
+               }
+               kfree(ename);
+       } else {
+               err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
+               err = -ecode;
+
+               p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
+       }
+
+       return err;
+
+out_err:
+       p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
+
+       return err;
+}
+
+/**
+ * p9_check_zc_errors - check 9p packet for error return and process it
+ * @c: current client instance
+ * @req: request to parse and check for error conditions
+ * @in_hdrlen: Size of response protocol buffer.
+ *
+ * returns error code if one is discovered, otherwise returns 0
+ *
+ * this will have to be more complicated if we have multiple
+ * error packet types
+ */
+
+static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
+                             struct iov_iter *uidata, int in_hdrlen)
+{
+       int err;
+       int ecode;
+       int8_t type;
+       char *ename = NULL;
+
+       err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
+       /*
+        * dump the response from server
+        * This should be after parse_header which poplulate pdu_fcall.
+        */
+       trace_9p_protocol_dump(c, req->rc);
+       if (err) {
+               p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
+               return err;
+       }
+
+       if (type != P9_RERROR && type != P9_RLERROR)
+               return 0;
+
+       if (!p9_is_proto_dotl(c)) {
+               /* Error is reported in string format */
+               int len;
+               /* 7 = header size for RERROR; */
+               int inline_len = in_hdrlen - 7;
+
+               len =  req->rc->size - req->rc->offset;
+               if (len > (P9_ZC_HDR_SZ - 7)) {
+                       err = -EFAULT;
+                       goto out_err;
+               }
+
+               ename = &req->rc->sdata[req->rc->offset];
+               if (len > inline_len) {
+                       /* We have error in external buffer */
+                       err = copy_from_iter(ename + inline_len,
+                                            len - inline_len, uidata);
+                       if (err != len - inline_len) {
+                               err = -EFAULT;
+                               goto out_err;
+                       }
+               }
+               ename = NULL;
+               err = p9pdu_readf(req->rc, c->proto_version, "s?d",
+                                 &ename, &ecode);
+               if (err)
+                       goto out_err;
+
+               if (p9_is_proto_dotu(c))
+                       err = -ecode;
+
+               if (!err || !IS_ERR_VALUE(err)) {
+                       err = p9_errstr2errno(ename, strlen(ename));
+
+                       p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
+                                -ecode, ename);
+               }
+               kfree(ename);
+       } else {
+               err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
+               err = -ecode;
+
+               p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
+       }
+       return err;
+
+out_err:
+       p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
+       return err;
+}
+
+static struct p9_req_t *
+p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
+
+/**
+ * p9_client_flush - flush (cancel) a request
+ * @c: client state
+ * @oldreq: request to cancel
+ *
+ * This sents a flush for a particular request and links
+ * the flush request to the original request.  The current
+ * code only supports a single flush request although the protocol
+ * allows for multiple flush requests to be sent for a single request.
+ *
+ */
+
+static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
+{
+       struct p9_req_t *req;
+       int16_t oldtag;
+       int err;
+
+       err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
+       if (err)
+               return err;
+
+       p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
+
+       req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       /*
+        * if we haven't received a response for oldreq,
+        * remove it from the list
+        */
+       if (oldreq->status == REQ_STATUS_SENT)
+               if (c->trans_mod->cancelled)
+                       c->trans_mod->cancelled(c, oldreq);
+
+       p9_free_req(c, req);
+       return 0;
+}
+
+static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
+                                             int8_t type, int req_size,
+                                             const char *fmt, va_list ap)
+{
+       int tag, err;
+       struct p9_req_t *req;
+
+       p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
+
+       /* we allow for any status other than disconnected */
+       if (c->status == Disconnected)
+               return ERR_PTR(-EIO);
+
+       /* if status is begin_disconnected we allow only clunk request */
+       if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
+               return ERR_PTR(-EIO);
+
+       tag = P9_NOTAG;
+       if (type != P9_TVERSION) {
+               tag = p9_idpool_get(c->tagpool);
+               if (tag < 0)
+                       return ERR_PTR(-ENOMEM);
+       }
+
+       req = p9_tag_alloc(c, tag, req_size);
+       if (IS_ERR(req))
+               return req;
+
+       /* marshall the data */
+       p9pdu_prepare(req->tc, tag, type);
+       err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
+       if (err)
+               goto reterr;
+       p9pdu_finalize(c, req->tc);
+       trace_9p_client_req(c, type, tag);
+       return req;
+reterr:
+       p9_free_req(c, req);
+       return ERR_PTR(err);
+}
+
+/**
+ * p9_client_rpc - issue a request and wait for a response
+ * @c: client session
+ * @type: type of request
+ * @fmt: protocol format string (see protocol.c)
+ *
+ * Returns request structure (which client must free using p9_free_req)
+ */
+
+static struct p9_req_t *
+p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
+{
+       va_list ap;
+       int sigpending, err;
+       unsigned long flags;
+       struct p9_req_t *req;
+
+       va_start(ap, fmt);
+       req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
+       va_end(ap);
+       if (IS_ERR(req))
+               return req;
+
+       if (signal_pending(current)) {
+               sigpending = 1;
+               clear_thread_flag(TIF_SIGPENDING);
+       } else
+               sigpending = 0;
+
+       err = c->trans_mod->request(c, req);
+       if (err < 0) {
+               if (err != -ERESTARTSYS && err != -EFAULT)
+                       c->status = Disconnected;
+               goto reterr;
+       }
+again:
+       /* Wait for the response */
+       err = wait_event_interruptible(*req->wq,
+                                      req->status >= REQ_STATUS_RCVD);
+
+       /*
+        * Make sure our req is coherent with regard to updates in other
+        * threads - echoes to wmb() in the callback
+        */
+       smp_rmb();
+
+       if ((err == -ERESTARTSYS) && (c->status == Connected)
+                                 && (type == P9_TFLUSH)) {
+               sigpending = 1;
+               clear_thread_flag(TIF_SIGPENDING);
+               goto again;
+       }
+
+       if (req->status == REQ_STATUS_ERROR) {
+               p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
+               err = req->t_err;
+       }
+       if ((err == -ERESTARTSYS) && (c->status == Connected)) {
+               p9_debug(P9_DEBUG_MUX, "flushing\n");
+               sigpending = 1;
+               clear_thread_flag(TIF_SIGPENDING);
+
+               if (c->trans_mod->cancel(c, req))
+                       p9_client_flush(c, req);
+
+               /* if we received the response anyway, don't signal error */
+               if (req->status == REQ_STATUS_RCVD)
+                       err = 0;
+       }
+       if (sigpending) {
+               spin_lock_irqsave(&current->sighand->siglock, flags);
+               recalc_sigpending();
+               spin_unlock_irqrestore(&current->sighand->siglock, flags);
+       }
+       if (err < 0)
+               goto reterr;
+
+       err = p9_check_errors(c, req);
+       trace_9p_client_res(c, type, req->rc->tag, err);
+       if (!err)
+               return req;
+reterr:
+       p9_free_req(c, req);
+       return ERR_PTR(safe_errno(err));
+}
+
+/**
+ * p9_client_zc_rpc - issue a request and wait for a response
+ * @c: client session
+ * @type: type of request
+ * @uidata: destination for zero copy read
+ * @uodata: source for zero copy write
+ * @inlen: read buffer size
+ * @olen: write buffer size
+ * @hdrlen: reader header size, This is the size of response protocol data
+ * @fmt: protocol format string (see protocol.c)
+ *
+ * Returns request structure (which client must free using p9_free_req)
+ */
+static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
+                                        struct iov_iter *uidata,
+                                        struct iov_iter *uodata,
+                                        int inlen, int olen, int in_hdrlen,
+                                        const char *fmt, ...)
+{
+       va_list ap;
+       int sigpending, err;
+       unsigned long flags;
+       struct p9_req_t *req;
+
+       va_start(ap, fmt);
+       /*
+        * We allocate a inline protocol data of only 4k bytes.
+        * The actual content is passed in zero-copy fashion.
+        */
+       req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
+       va_end(ap);
+       if (IS_ERR(req))
+               return req;
+
+       if (signal_pending(current)) {
+               sigpending = 1;
+               clear_thread_flag(TIF_SIGPENDING);
+       } else
+               sigpending = 0;
+
+       err = c->trans_mod->zc_request(c, req, uidata, uodata,
+                                      inlen, olen, in_hdrlen);
+       if (err < 0) {
+               if (err == -EIO)
+                       c->status = Disconnected;
+               goto reterr;
+       }
+       if (req->status == REQ_STATUS_ERROR) {
+               p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
+               err = req->t_err;
+       }
+       if ((err == -ERESTARTSYS) && (c->status == Connected)) {
+               p9_debug(P9_DEBUG_MUX, "flushing\n");
+               sigpending = 1;
+               clear_thread_flag(TIF_SIGPENDING);
+
+               if (c->trans_mod->cancel(c, req))
+                       p9_client_flush(c, req);
+
+               /* if we received the response anyway, don't signal error */
+               if (req->status == REQ_STATUS_RCVD)
+                       err = 0;
+       }
+       if (sigpending) {
+               spin_lock_irqsave(&current->sighand->siglock, flags);
+               recalc_sigpending();
+               spin_unlock_irqrestore(&current->sighand->siglock, flags);
+       }
+       if (err < 0)
+               goto reterr;
+
+       err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
+       trace_9p_client_res(c, type, req->rc->tag, err);
+       if (!err)
+               return req;
+reterr:
+       p9_free_req(c, req);
+       return ERR_PTR(safe_errno(err));
+}
+
+static struct p9_fid *p9_fid_create(struct p9_client *clnt)
+{
+       int ret;
+       struct p9_fid *fid;
+       unsigned long flags;
+
+       p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
+       fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
+       if (!fid)
+               return ERR_PTR(-ENOMEM);
+
+       ret = p9_idpool_get(clnt->fidpool);
+       if (ret < 0) {
+               ret = -ENOSPC;
+               goto error;
+       }
+       fid->fid = ret;
+
+       memset(&fid->qid, 0, sizeof(struct p9_qid));
+       fid->mode = -1;
+       fid->uid = current_fsuid();
+       fid->clnt = clnt;
+       fid->rdir = NULL;
+       spin_lock_irqsave(&clnt->lock, flags);
+       list_add(&fid->flist, &clnt->fidlist);
+       spin_unlock_irqrestore(&clnt->lock, flags);
+
+       return fid;
+
+error:
+       kfree(fid);
+       return ERR_PTR(ret);
+}
+
+static void p9_fid_destroy(struct p9_fid *fid)
+{
+       struct p9_client *clnt;
+       unsigned long flags;
+
+       p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
+       clnt = fid->clnt;
+       p9_idpool_put(fid->fid, clnt->fidpool);
+       spin_lock_irqsave(&clnt->lock, flags);
+       list_del(&fid->flist);
+       spin_unlock_irqrestore(&clnt->lock, flags);
+       kfree(fid->rdir);
+       kfree(fid);
+}
+
+static int p9_client_version(struct p9_client *c)
+{
+       int err = 0;
+       struct p9_req_t *req;
+       char *version;
+       int msize;
+
+       p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
+                c->msize, c->proto_version);
+
+       switch (c->proto_version) {
+       case p9_proto_2000L:
+               req = p9_client_rpc(c, P9_TVERSION, "ds",
+                                       c->msize, "9P2000.L");
+               break;
+       case p9_proto_2000u:
+               req = p9_client_rpc(c, P9_TVERSION, "ds",
+                                       c->msize, "9P2000.u");
+               break;
+       case p9_proto_legacy:
+               req = p9_client_rpc(c, P9_TVERSION, "ds",
+                                       c->msize, "9P2000");
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
+       if (err) {
+               p9_debug(P9_DEBUG_9P, "version error %d\n", err);
+               trace_9p_protocol_dump(c, req->rc);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
+       if (!strncmp(version, "9P2000.L", 8))
+               c->proto_version = p9_proto_2000L;
+       else if (!strncmp(version, "9P2000.u", 8))
+               c->proto_version = p9_proto_2000u;
+       else if (!strncmp(version, "9P2000", 6))
+               c->proto_version = p9_proto_legacy;
+       else {
+               err = -EREMOTEIO;
+               goto error;
+       }
+
+       if (msize < c->msize)
+               c->msize = msize;
+
+error:
+       kfree(version);
+       p9_free_req(c, req);
+
+       return err;
+}
+
+struct p9_client *p9_client_create(const char *dev_name, char *options)
+{
+       int err;
+       struct p9_client *clnt;
+       char *client_id;
+
+       err = 0;
+       clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
+       if (!clnt)
+               return ERR_PTR(-ENOMEM);
+
+       clnt->trans_mod = NULL;
+       clnt->trans = NULL;
+
+       client_id = utsname()->nodename;
+       memcpy(clnt->name, client_id, strlen(client_id) + 1);
+
+       spin_lock_init(&clnt->lock);
+       INIT_LIST_HEAD(&clnt->fidlist);
+
+       err = p9_tag_init(clnt);
+       if (err < 0)
+               goto free_client;
+
+       err = parse_opts(options, clnt);
+       if (err < 0)
+               goto destroy_tagpool;
+
+       if (!clnt->trans_mod)
+               clnt->trans_mod = v9fs_get_default_trans();
+
+       if (clnt->trans_mod == NULL) {
+               err = -EPROTONOSUPPORT;
+               p9_debug(P9_DEBUG_ERROR,
+                        "No transport defined or default transport\n");
+               goto destroy_tagpool;
+       }
+
+       clnt->fidpool = p9_idpool_create();
+       if (IS_ERR(clnt->fidpool)) {
+               err = PTR_ERR(clnt->fidpool);
+               goto put_trans;
+       }
+
+       p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
+                clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
+
+       err = clnt->trans_mod->create(clnt, dev_name, options);
+       if (err)
+               goto destroy_fidpool;
+
+       if (clnt->msize > clnt->trans_mod->maxsize)
+               clnt->msize = clnt->trans_mod->maxsize;
+
+       err = p9_client_version(clnt);
+       if (err)
+               goto close_trans;
+
+       return clnt;
+
+close_trans:
+       clnt->trans_mod->close(clnt);
+destroy_fidpool:
+       p9_idpool_destroy(clnt->fidpool);
+put_trans:
+       v9fs_put_trans(clnt->trans_mod);
+destroy_tagpool:
+       p9_idpool_destroy(clnt->tagpool);
+free_client:
+       kfree(clnt);
+       return ERR_PTR(err);
+}
+EXPORT_SYMBOL(p9_client_create);
+
+void p9_client_destroy(struct p9_client *clnt)
+{
+       struct p9_fid *fid, *fidptr;
+
+       p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
+
+       if (clnt->trans_mod)
+               clnt->trans_mod->close(clnt);
+
+       v9fs_put_trans(clnt->trans_mod);
+
+       list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
+               pr_info("Found fid %d not clunked\n", fid->fid);
+               p9_fid_destroy(fid);
+       }
+
+       if (clnt->fidpool)
+               p9_idpool_destroy(clnt->fidpool);
+
+       p9_tag_cleanup(clnt);
+
+       kfree(clnt);
+}
+EXPORT_SYMBOL(p9_client_destroy);
+
+void p9_client_disconnect(struct p9_client *clnt)
+{
+       p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
+       clnt->status = Disconnected;
+}
+EXPORT_SYMBOL(p9_client_disconnect);
+
+void p9_client_begin_disconnect(struct p9_client *clnt)
+{
+       p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
+       clnt->status = BeginDisconnect;
+}
+EXPORT_SYMBOL(p9_client_begin_disconnect);
+
+struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
+       char *uname, kuid_t n_uname, char *aname)
+{
+       int err = 0;
+       struct p9_req_t *req;
+       struct p9_fid *fid;
+       struct p9_qid qid;
+
+
+       p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
+                afid ? afid->fid : -1, uname, aname);
+       fid = p9_fid_create(clnt);
+       if (IS_ERR(fid)) {
+               err = PTR_ERR(fid);
+               fid = NULL;
+               goto error;
+       }
+       fid->uid = n_uname;
+
+       req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
+                       afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               p9_free_req(clnt, req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
+                qid.type, (unsigned long long)qid.path, qid.version);
+
+       memmove(&fid->qid, &qid, sizeof(struct p9_qid));
+
+       p9_free_req(clnt, req);
+       return fid;
+
+error:
+       if (fid)
+               p9_fid_destroy(fid);
+       return ERR_PTR(err);
+}
+EXPORT_SYMBOL(p9_client_attach);
+
+struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
+               char **wnames, int clone)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_fid *fid;
+       struct p9_qid *wqids;
+       struct p9_req_t *req;
+       uint16_t nwqids, count;
+
+       err = 0;
+       wqids = NULL;
+       clnt = oldfid->clnt;
+       if (clone) {
+               fid = p9_fid_create(clnt);
+               if (IS_ERR(fid)) {
+                       err = PTR_ERR(fid);
+                       fid = NULL;
+                       goto error;
+               }
+
+               fid->uid = oldfid->uid;
+       } else
+               fid = oldfid;
+
+
+       p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
+                oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
+
+       req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
+                                                               nwname, wnames);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               p9_free_req(clnt, req);
+               goto clunk_fid;
+       }
+       p9_free_req(clnt, req);
+
+       p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
+
+       if (nwqids != nwname) {
+               err = -ENOENT;
+               goto clunk_fid;
+       }
+
+       for (count = 0; count < nwqids; count++)
+               p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
+                       count, wqids[count].type,
+                       (unsigned long long)wqids[count].path,
+                       wqids[count].version);
+
+       if (nwname)
+               memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
+       else
+               fid->qid = oldfid->qid;
+
+       kfree(wqids);
+       return fid;
+
+clunk_fid:
+       kfree(wqids);
+       p9_client_clunk(fid);
+       fid = NULL;
+
+error:
+       if (fid && (fid != oldfid))
+               p9_fid_destroy(fid);
+
+       return ERR_PTR(err);
+}
+EXPORT_SYMBOL(p9_client_walk);
+
+int p9_client_open(struct p9_fid *fid, int mode)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+       struct p9_qid qid;
+       int iounit;
+
+       clnt = fid->clnt;
+       p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
+               p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
+       err = 0;
+
+       if (fid->mode != -1)
+               return -EINVAL;
+
+       if (p9_is_proto_dotl(clnt))
+               req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
+       else
+               req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto free_and_error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
+               p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
+               (unsigned long long)qid.path, qid.version, iounit);
+
+       fid->mode = mode;
+       fid->iounit = iounit;
+
+free_and_error:
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_open);
+
+int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
+               kgid_t gid, struct p9_qid *qid)
+{
+       int err = 0;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+       int iounit;
+
+       p9_debug(P9_DEBUG_9P,
+                       ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
+                       ofid->fid, name, flags, mode,
+                       from_kgid(&init_user_ns, gid));
+       clnt = ofid->clnt;
+
+       if (ofid->mode != -1)
+               return -EINVAL;
+
+       req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
+                       mode, gid);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto free_and_error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
+                       qid->type,
+                       (unsigned long long)qid->path,
+                       qid->version, iounit);
+
+       ofid->mode = mode;
+       ofid->iounit = iounit;
+
+free_and_error:
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_create_dotl);
+
+int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
+                    char *extension)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+       struct p9_qid qid;
+       int iounit;
+
+       p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
+                                               fid->fid, name, perm, mode);
+       err = 0;
+       clnt = fid->clnt;
+
+       if (fid->mode != -1)
+               return -EINVAL;
+
+       req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
+                               mode, extension);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto free_and_error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
+                               qid.type,
+                               (unsigned long long)qid.path,
+                               qid.version, iounit);
+
+       fid->mode = mode;
+       fid->iounit = iounit;
+
+free_and_error:
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_fcreate);
+
+int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
+               struct p9_qid *qid)
+{
+       int err = 0;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
+                       dfid->fid, name, symtgt);
+       clnt = dfid->clnt;
+
+       req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
+                       gid);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto free_and_error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
+                       qid->type, (unsigned long long)qid->path, qid->version);
+
+free_and_error:
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_symlink);
+
+int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
+{
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
+                       dfid->fid, oldfid->fid, newname);
+       clnt = dfid->clnt;
+       req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
+                       newname);
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
+       p9_free_req(clnt, req);
+       return 0;
+}
+EXPORT_SYMBOL(p9_client_link);
+
+int p9_client_fsync(struct p9_fid *fid, int datasync)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
+                       fid->fid, datasync);
+       err = 0;
+       clnt = fid->clnt;
+
+       req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
+
+       p9_free_req(clnt, req);
+
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_fsync);
+
+int p9_client_clunk(struct p9_fid *fid)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+       int retries = 0;
+
+       if (!fid) {
+               pr_warn("%s (%d): Trying to clunk with NULL fid\n",
+                       __func__, task_pid_nr(current));
+               dump_stack();
+               return 0;
+       }
+
+again:
+       p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
+                                                               retries);
+       err = 0;
+       clnt = fid->clnt;
+
+       req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
+
+       p9_free_req(clnt, req);
+error:
+       /*
+        * Fid is not valid even after a failed clunk
+        * If interrupted, retry once then give up and
+        * leak fid until umount.
+        */
+       if (err == -ERESTARTSYS) {
+               if (retries++ == 0)
+                       goto again;
+       } else
+               p9_fid_destroy(fid);
+       return err;
+}
+EXPORT_SYMBOL(p9_client_clunk);
+
+int p9_client_remove(struct p9_fid *fid)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
+       err = 0;
+       clnt = fid->clnt;
+
+       req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
+
+       p9_free_req(clnt, req);
+error:
+       if (err == -ERESTARTSYS)
+               p9_client_clunk(fid);
+       else
+               p9_fid_destroy(fid);
+       return err;
+}
+EXPORT_SYMBOL(p9_client_remove);
+
+int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
+{
+       int err = 0;
+       struct p9_req_t *req;
+       struct p9_client *clnt;
+
+       p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
+                  dfid->fid, name, flags);
+
+       clnt = dfid->clnt;
+       req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
+
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_unlinkat);
+
+int
+p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
+{
+       struct p9_client *clnt = fid->clnt;
+       struct p9_req_t *req;
+       int total = 0;
+
+       p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
+                  fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
+
+       while (iov_iter_count(to)) {
+               int count = iov_iter_count(to);
+               int rsize, non_zc = 0;
+               char *dataptr;
+                       
+               rsize = fid->iounit;
+               if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
+                       rsize = clnt->msize - P9_IOHDRSZ;
+
+               if (count < rsize)
+                       rsize = count;
+
+               /* Don't bother zerocopy for small IO (< 1024) */
+               if (clnt->trans_mod->zc_request && rsize > 1024) {
+                       /*
+                        * response header len is 11
+                        * PDU Header(7) + IO Size (4)
+                        */
+                       req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
+                                              0, 11, "dqd", fid->fid,
+                                              offset, rsize);
+               } else {
+                       non_zc = 1;
+                       req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
+                                           rsize);
+               }
+               if (IS_ERR(req)) {
+                       *err = PTR_ERR(req);
+                       break;
+               }
+
+               *err = p9pdu_readf(req->rc, clnt->proto_version,
+                                  "D", &count, &dataptr);
+               if (*err) {
+                       trace_9p_protocol_dump(clnt, req->rc);
+                       p9_free_req(clnt, req);
+                       break;
+               }
+
+               p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
+               if (!count) {
+                       p9_free_req(clnt, req);
+                       break;
+               }
+
+               if (non_zc) {
+                       int n = copy_to_iter(dataptr, count, to);
+                       total += n;
+                       offset += n;
+                       if (n != count) {
+                               *err = -EFAULT;
+                               p9_free_req(clnt, req);
+                               break;
+                       }
+               } else {
+                       iov_iter_advance(to, count);
+                       total += count;
+                       offset += count;
+               }
+               p9_free_req(clnt, req);
+       }
+       return total;
+}
+EXPORT_SYMBOL(p9_client_read);
+
+int
+p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
+{
+       struct p9_client *clnt = fid->clnt;
+       struct p9_req_t *req;
+       int total = 0;
+
+       p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
+                               fid->fid, (unsigned long long) offset,
+                               iov_iter_count(from));
+
+       while (iov_iter_count(from)) {
+               int count = iov_iter_count(from);
+               int rsize = fid->iounit;
+               if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
+                       rsize = clnt->msize - P9_IOHDRSZ;
+
+               if (count < rsize)
+                       rsize = count;
+
+               /* Don't bother zerocopy for small IO (< 1024) */
+               if (clnt->trans_mod->zc_request && rsize > 1024) {
+                       req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
+                                              rsize, P9_ZC_HDR_SZ, "dqd",
+                                              fid->fid, offset, rsize);
+               } else {
+                       req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
+                                                   offset, rsize, from);
+               }
+               if (IS_ERR(req)) {
+                       *err = PTR_ERR(req);
+                       break;
+               }
+
+               *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
+               if (*err) {
+                       trace_9p_protocol_dump(clnt, req->rc);
+                       p9_free_req(clnt, req);
+               }
+
+               p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
+
+               p9_free_req(clnt, req);
+               iov_iter_advance(from, count);
+               total += count;
+               offset += count;
+       }
+       return total;
+}
+EXPORT_SYMBOL(p9_client_write);
+
+struct p9_wstat *p9_client_stat(struct p9_fid *fid)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
+       struct p9_req_t *req;
+       u16 ignored;
+
+       p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
+
+       if (!ret)
+               return ERR_PTR(-ENOMEM);
+
+       err = 0;
+       clnt = fid->clnt;
+
+       req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               p9_free_req(clnt, req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P,
+               "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
+               "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
+               "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
+               "<<<    uid=%d gid=%d n_muid=%d\n",
+               ret->size, ret->type, ret->dev, ret->qid.type,
+               (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
+               ret->atime, ret->mtime, (unsigned long long)ret->length,
+               ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
+               from_kuid(&init_user_ns, ret->n_uid),
+               from_kgid(&init_user_ns, ret->n_gid),
+               from_kuid(&init_user_ns, ret->n_muid));
+
+       p9_free_req(clnt, req);
+       return ret;
+
+error:
+       kfree(ret);
+       return ERR_PTR(err);
+}
+EXPORT_SYMBOL(p9_client_stat);
+
+struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
+                                                       u64 request_mask)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
+                                                               GFP_KERNEL);
+       struct p9_req_t *req;
+
+       p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
+                                                       fid->fid, request_mask);
+
+       if (!ret)
+               return ERR_PTR(-ENOMEM);
+
+       err = 0;
+       clnt = fid->clnt;
+
+       req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               p9_free_req(clnt, req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P,
+               "<<< RGETATTR st_result_mask=%lld\n"
+               "<<< qid=%x.%llx.%x\n"
+               "<<< st_mode=%8.8x st_nlink=%llu\n"
+               "<<< st_uid=%d st_gid=%d\n"
+               "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
+               "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
+               "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
+               "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
+               "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
+               "<<< st_gen=%lld st_data_version=%lld",
+               ret->st_result_mask, ret->qid.type, ret->qid.path,
+               ret->qid.version, ret->st_mode, ret->st_nlink,
+               from_kuid(&init_user_ns, ret->st_uid),
+               from_kgid(&init_user_ns, ret->st_gid),
+               ret->st_rdev, ret->st_size, ret->st_blksize,
+               ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
+               ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
+               ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
+               ret->st_gen, ret->st_data_version);
+
+       p9_free_req(clnt, req);
+       return ret;
+
+error:
+       kfree(ret);
+       return ERR_PTR(err);
+}
+EXPORT_SYMBOL(p9_client_getattr_dotl);
+
+static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
+{
+       int ret;
+
+       /* NOTE: size shouldn't include its own length */
+       /* size[2] type[2] dev[4] qid[13] */
+       /* mode[4] atime[4] mtime[4] length[8]*/
+       /* name[s] uid[s] gid[s] muid[s] */
+       ret = 2+4+13+4+4+4+8+2+2+2+2;
+
+       if (wst->name)
+               ret += strlen(wst->name);
+       if (wst->uid)
+               ret += strlen(wst->uid);
+       if (wst->gid)
+               ret += strlen(wst->gid);
+       if (wst->muid)
+               ret += strlen(wst->muid);
+
+       if ((proto_version == p9_proto_2000u) ||
+               (proto_version == p9_proto_2000L)) {
+               ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
+               if (wst->extension)
+                       ret += strlen(wst->extension);
+       }
+
+       return ret;
+}
+
+int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
+{
+       int err;
+       struct p9_req_t *req;
+       struct p9_client *clnt;
+
+       err = 0;
+       clnt = fid->clnt;
+       wst->size = p9_client_statsize(wst, clnt->proto_version);
+       p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
+       p9_debug(P9_DEBUG_9P,
+               "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
+               "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
+               "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
+               "     uid=%d gid=%d n_muid=%d\n",
+               wst->size, wst->type, wst->dev, wst->qid.type,
+               (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
+               wst->atime, wst->mtime, (unsigned long long)wst->length,
+               wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
+               from_kuid(&init_user_ns, wst->n_uid),
+               from_kgid(&init_user_ns, wst->n_gid),
+               from_kuid(&init_user_ns, wst->n_muid));
+
+       req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
+
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_wstat);
+
+int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
+{
+       int err;
+       struct p9_req_t *req;
+       struct p9_client *clnt;
+
+       err = 0;
+       clnt = fid->clnt;
+       p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
+       p9_debug(P9_DEBUG_9P,
+               "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
+               "    atime_sec=%lld atime_nsec=%lld\n"
+               "    mtime_sec=%lld mtime_nsec=%lld\n",
+               p9attr->valid, p9attr->mode,
+               from_kuid(&init_user_ns, p9attr->uid),
+               from_kgid(&init_user_ns, p9attr->gid),
+               p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
+               p9attr->mtime_sec, p9attr->mtime_nsec);
+
+       req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
+
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_setattr);
+
+int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
+{
+       int err;
+       struct p9_req_t *req;
+       struct p9_client *clnt;
+
+       err = 0;
+       clnt = fid->clnt;
+
+       p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
+
+       req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
+               &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
+               &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               p9_free_req(clnt, req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
+               "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
+               "fsid %llu namelen %ld\n",
+               fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
+               sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
+               sb->fsid, (long int)sb->namelen);
+
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_statfs);
+
+int p9_client_rename(struct p9_fid *fid,
+                    struct p9_fid *newdirfid, const char *name)
+{
+       int err;
+       struct p9_req_t *req;
+       struct p9_client *clnt;
+
+       err = 0;
+       clnt = fid->clnt;
+
+       p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
+                       fid->fid, newdirfid->fid, name);
+
+       req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
+                       newdirfid->fid, name);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
+
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_rename);
+
+int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
+                      struct p9_fid *newdirfid, const char *new_name)
+{
+       int err;
+       struct p9_req_t *req;
+       struct p9_client *clnt;
+
+       err = 0;
+       clnt = olddirfid->clnt;
+
+       p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
+                  " newdirfid %d new name %s\n", olddirfid->fid, old_name,
+                  newdirfid->fid, new_name);
+
+       req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
+                           old_name, newdirfid->fid, new_name);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
+                  newdirfid->fid, new_name);
+
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_renameat);
+
+/*
+ * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
+ */
+struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
+                               const char *attr_name, u64 *attr_size)
+{
+       int err;
+       struct p9_req_t *req;
+       struct p9_client *clnt;
+       struct p9_fid *attr_fid;
+
+       err = 0;
+       clnt = file_fid->clnt;
+       attr_fid = p9_fid_create(clnt);
+       if (IS_ERR(attr_fid)) {
+               err = PTR_ERR(attr_fid);
+               attr_fid = NULL;
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P,
+               ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
+               file_fid->fid, attr_fid->fid, attr_name);
+
+       req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
+                       file_fid->fid, attr_fid->fid, attr_name);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+       err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               p9_free_req(clnt, req);
+               goto clunk_fid;
+       }
+       p9_free_req(clnt, req);
+       p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
+               attr_fid->fid, *attr_size);
+       return attr_fid;
+clunk_fid:
+       p9_client_clunk(attr_fid);
+       attr_fid = NULL;
+error:
+       if (attr_fid && (attr_fid != file_fid))
+               p9_fid_destroy(attr_fid);
+
+       return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
+
+int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
+                       u64 attr_size, int flags)
+{
+       int err;
+       struct p9_req_t *req;
+       struct p9_client *clnt;
+
+       p9_debug(P9_DEBUG_9P,
+               ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
+               fid->fid, name, (long long)attr_size, flags);
+       err = 0;
+       clnt = fid->clnt;
+       req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
+                       fid->fid, name, attr_size, flags);
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
+
+int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
+{
+       int err, rsize, non_zc = 0;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+       char *dataptr;
+       struct kvec kv = {.iov_base = data, .iov_len = count};
+       struct iov_iter to;
+
+       iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
+
+       p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
+                               fid->fid, (unsigned long long) offset, count);
+
+       err = 0;
+       clnt = fid->clnt;
+
+       rsize = fid->iounit;
+       if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
+               rsize = clnt->msize - P9_READDIRHDRSZ;
+
+       if (count < rsize)
+               rsize = count;
+
+       /* Don't bother zerocopy for small IO (< 1024) */
+       if (clnt->trans_mod->zc_request && rsize > 1024) {
+               /*
+                * response header len is 11
+                * PDU Header(7) + IO Size (4)
+                */
+               req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
+                                      11, "dqd", fid->fid, offset, rsize);
+       } else {
+               non_zc = 1;
+               req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
+                                   offset, rsize);
+       }
+       if (IS_ERR(req)) {
+               err = PTR_ERR(req);
+               goto error;
+       }
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto free_and_error;
+       }
+
+       p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
+
+       if (non_zc)
+               memmove(data, dataptr, count);
+
+       p9_free_req(clnt, req);
+       return count;
+
+free_and_error:
+       p9_free_req(clnt, req);
+error:
+       return err;
+}
+EXPORT_SYMBOL(p9_client_readdir);
+
+int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
+                       dev_t rdev, kgid_t gid, struct p9_qid *qid)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       err = 0;
+       clnt = fid->clnt;
+       p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
+               "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
+       req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
+               MAJOR(rdev), MINOR(rdev), gid);
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
+                               (unsigned long long)qid->path, qid->version);
+
+error:
+       p9_free_req(clnt, req);
+       return err;
+
+}
+EXPORT_SYMBOL(p9_client_mknod_dotl);
+
+int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
+                               kgid_t gid, struct p9_qid *qid)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       err = 0;
+       clnt = fid->clnt;
+       p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
+                fid->fid, name, mode, from_kgid(&init_user_ns, gid));
+       req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
+               gid);
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
+                               (unsigned long long)qid->path, qid->version);
+
+error:
+       p9_free_req(clnt, req);
+       return err;
+
+}
+EXPORT_SYMBOL(p9_client_mkdir_dotl);
+
+int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       err = 0;
+       clnt = fid->clnt;
+       p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
+                       "start %lld length %lld proc_id %d client_id %s\n",
+                       fid->fid, flock->type, flock->flags, flock->start,
+                       flock->length, flock->proc_id, flock->client_id);
+
+       req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
+                               flock->flags, flock->start, flock->length,
+                                       flock->proc_id, flock->client_id);
+
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
+error:
+       p9_free_req(clnt, req);
+       return err;
+
+}
+EXPORT_SYMBOL(p9_client_lock_dotl);
+
+int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       err = 0;
+       clnt = fid->clnt;
+       p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
+               "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
+               glock->start, glock->length, glock->proc_id, glock->client_id);
+
+       req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
+               glock->start, glock->length, glock->proc_id, glock->client_id);
+
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
+                       &glock->start, &glock->length, &glock->proc_id,
+                       &glock->client_id);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
+               "proc_id %d client_id %s\n", glock->type, glock->start,
+               glock->length, glock->proc_id, glock->client_id);
+error:
+       p9_free_req(clnt, req);
+       return err;
+}
+EXPORT_SYMBOL(p9_client_getlock_dotl);
+
+int p9_client_readlink(struct p9_fid *fid, char **target)
+{
+       int err;
+       struct p9_client *clnt;
+       struct p9_req_t *req;
+
+       err = 0;
+       clnt = fid->clnt;
+       p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
+
+       req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
+       if (err) {
+               trace_9p_protocol_dump(clnt, req->rc);
+               goto error;
+       }
+       p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
+error:
+       p9_free_req(clnt, req);
+       return err;
+}
+EXPORT_SYMBOL(p9_client_readlink);