9p: embed fcall in req to round down buffer allocs

'msize' is often a power of two, or at least page-aligned, so avoiding
an overhead of two dozen bytes for each allocation will help the
allocator do its work and reduce memory fragmentation.

Link: http://lkml.kernel.org/r/1533825236-22896-1-git-send-email-asmadeus@codewreck.org
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Jun Piao <piaojun@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>

5 files changed, 122 insertions, 116 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index 88db45966740..ed78751aee7c 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -231,16 +231,20 @@ free_and_return:
         return ret;
 }
 
-static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
+static int p9_fcall_init(struct p9_fcall *fc, int alloc_msize)
 {
-        struct p9_fcall *fc;
-        fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
-        if (!fc)
-                return NULL;
+        fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
+        if (!fc->sdata)
+                return -ENOMEM;
         fc->capacity = alloc_msize;
-        fc->sdata = (char *) fc + sizeof(struct p9_fcall);
-        return fc;
+        return 0;
+}
+
+void p9_fcall_fini(struct p9_fcall *fc)
+{
+        kfree(fc->sdata);
 }
+EXPORT_SYMBOL(p9_fcall_fini);
 
 static struct kmem_cache *p9_req_cache;
 
@@ -263,13 +267,13 @@ p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
         if (!req)
                 return NULL;
 
-        req->tc = p9_fcall_alloc(alloc_msize);
-        req->rc = p9_fcall_alloc(alloc_msize);
-        if (!req->tc || !req->rc)
+        if (p9_fcall_init(&req->tc, alloc_msize))
+                goto free_req;
+        if (p9_fcall_init(&req->rc, alloc_msize))
                 goto free;
 
-        p9pdu_reset(req->tc);
-        p9pdu_reset(req->rc);
+        p9pdu_reset(&req->tc);
+        p9pdu_reset(&req->rc);
         req->status = REQ_STATUS_ALLOC;
         init_waitqueue_head(&req->wq);
         INIT_LIST_HEAD(&req->req_list);
@@ -281,7 +285,7 @@ p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
                                 GFP_NOWAIT);
         else
                 tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT);
-        req->tc->tag = tag;
+        req->tc.tag = tag;
         spin_unlock_irq(&c->lock);
         idr_preload_end();
         if (tag < 0)
@@ -290,8 +294,9 @@ p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
         return req;
 
 free:
-        kfree(req->tc);
-        kfree(req->rc);
+        p9_fcall_fini(&req->tc);
+        p9_fcall_fini(&req->rc);
+free_req:
         kmem_cache_free(p9_req_cache, req);
         return ERR_PTR(-ENOMEM);
 }
@@ -329,14 +334,14 @@ EXPORT_SYMBOL(p9_tag_lookup);
 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 {
         unsigned long flags;
-        u16 tag = r->tc->tag;
+        u16 tag = r->tc.tag;
 
         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
         spin_lock_irqsave(&c->lock, flags);
         idr_remove(&c->reqs, tag);
         spin_unlock_irqrestore(&c->lock, flags);
-        kfree(r->tc);
-        kfree(r->rc);
+        p9_fcall_fini(&r->tc);
+        p9_fcall_fini(&r->rc);
         kmem_cache_free(p9_req_cache, r);
 }
 
@@ -368,7 +373,7 @@ static void p9_tag_cleanup(struct p9_client *c)
  */
 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);
+        p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag);
 
         /*
          * This barrier is needed to make sure any change made to req before
@@ -378,7 +383,7 @@ void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
         req->status = status;
 
         wake_up(&req->wq);
-        p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
+        p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag);
 }
 EXPORT_SYMBOL(p9_client_cb);
 
@@ -449,18 +454,18 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
         int err;
         int ecode;
 
-        err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
-        if (req->rc->size >= c->msize) {
+        err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
+        if (req->rc.size >= c->msize) {
                 p9_debug(P9_DEBUG_ERROR,
                          "requested packet size too big: %d\n",
-                         req->rc->size);
+                         req->rc.size);
                 return -EIO;
         }
         /*
          * dump the response from server
          * This should be after check errors which poplulate pdu_fcall.
          */
-        trace_9p_protocol_dump(c, req->rc);
+        trace_9p_protocol_dump(c, &req->rc);
         if (err) {
                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
                 return err;
@@ -470,7 +475,7 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 
         if (!p9_is_proto_dotl(c)) {
                 char *ename;
-                err = p9pdu_readf(req->rc, c->proto_version, "s?d",
+                err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
                                   &ename, &ecode);
                 if (err)
                         goto out_err;
@@ -486,7 +491,7 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
                 }
                 kfree(ename);
         } else {
-                err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
+                err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
                 err = -ecode;
 
                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
@@ -520,12 +525,12 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
         int8_t type;
         char *ename = NULL;
 
-        err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
+        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);
+        trace_9p_protocol_dump(c, &req->rc);
         if (err) {
                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
                 return err;
@@ -540,13 +545,13 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
                 /* 7 = header size for RERROR; */
                 int inline_len = in_hdrlen - 7;
 
-                len =  req->rc->size - req->rc->offset;
+                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];
+                ename = &req->rc.sdata[req->rc.offset];
                 if (len > inline_len) {
                         /* We have error in external buffer */
                         if (!copy_from_iter_full(ename + inline_len,
@@ -556,7 +561,7 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
                         }
                 }
                 ename = NULL;
-                err = p9pdu_readf(req->rc, c->proto_version, "s?d",
+                err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
                                   &ename, &ecode);
                 if (err)
                         goto out_err;
@@ -572,7 +577,7 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
                 }
                 kfree(ename);
         } else {
-                err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
+                err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
                 err = -ecode;
 
                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
@@ -605,7 +610,7 @@ static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
         int16_t oldtag;
         int err;
 
-        err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
+        err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
         if (err)
                 return err;
 
@@ -649,12 +654,12 @@ static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
                 return req;
 
         /* marshall the data */
-        p9pdu_prepare(req->tc, req->tc->tag, type);
-        err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
+        p9pdu_prepare(&req->tc, 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, req->tc->tag);
+        p9pdu_finalize(c, &req->tc);
+        trace_9p_client_req(c, type, req->tc.tag);
         return req;
 reterr:
         p9_free_req(c, req);
@@ -739,7 +744,7 @@ recalc_sigpending:
                 goto reterr;
 
         err = p9_check_errors(c, req);
-        trace_9p_client_res(c, type, req->rc->tag, err);
+        trace_9p_client_res(c, type, req->rc.tag, err);
         if (!err)
                 return req;
 reterr:
@@ -821,7 +826,7 @@ recalc_sigpending:
                 goto reterr;
 
         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
-        trace_9p_client_res(c, type, req->rc->tag, err);
+        trace_9p_client_res(c, type, req->rc.tag, err);
         if (!err)
                 return req;
 reterr:
@@ -904,10 +909,10 @@ static int p9_client_version(struct p9_client *c)
         if (IS_ERR(req))
                 return PTR_ERR(req);
 
-        err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
+        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);
+                trace_9p_protocol_dump(c, &req->rc);
                 goto error;
         }
 
@@ -1056,9 +1061,9 @@ struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 p9_free_req(clnt, req);
                 goto error;
         }
@@ -1113,9 +1118,9 @@ struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 p9_free_req(clnt, req);
                 goto clunk_fid;
         }
@@ -1180,9 +1185,9 @@ int p9_client_open(struct p9_fid *fid, int mode)
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto free_and_error;
         }
 
@@ -1224,9 +1229,9 @@ int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto free_and_error;
         }
 
@@ -1269,9 +1274,9 @@ int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto free_and_error;
         }
 
@@ -1308,9 +1313,9 @@ int p9_client_symlink(struct p9_fid *dfid, const char *name,
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto free_and_error;
         }
 
@@ -1506,10 +1511,10 @@ p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
                         break;
                 }
 
-                *err = p9pdu_readf(req->rc, clnt->proto_version,
+                *err = p9pdu_readf(&req->rc, clnt->proto_version,
                                    "D", &count, &dataptr);
                 if (*err) {
-                        trace_9p_protocol_dump(clnt, req->rc);
+                        trace_9p_protocol_dump(clnt, &req->rc);
                         p9_free_req(clnt, req);
                         break;
                 }
@@ -1579,9 +1584,9 @@ p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
                         break;
                 }
 
-                *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
+                *err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
                 if (*err) {
-                        trace_9p_protocol_dump(clnt, req->rc);
+                        trace_9p_protocol_dump(clnt, &req->rc);
                         p9_free_req(clnt, req);
                         break;
                 }
@@ -1623,9 +1628,9 @@ struct p9_wstat *p9_client_stat(struct p9_fid *fid)
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 p9_free_req(clnt, req);
                 goto error;
         }
@@ -1676,9 +1681,9 @@ struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 p9_free_req(clnt, req);
                 goto error;
         }
@@ -1828,11 +1833,11 @@ int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
                 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);
+        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);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 p9_free_req(clnt, req);
                 goto error;
         }
@@ -1936,9 +1941,9 @@ struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
                 err = PTR_ERR(req);
                 goto error;
         }
-        err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 p9_free_req(clnt, req);
                 goto clunk_fid;
         }
@@ -2024,9 +2029,9 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
                 goto error;
         }
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto free_and_error;
         }
         if (rsize < count) {
@@ -2065,9 +2070,9 @@ int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
         if (IS_ERR(req))
                 return PTR_ERR(req);
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto error;
         }
         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
@@ -2096,9 +2101,9 @@ int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
         if (IS_ERR(req))
                 return PTR_ERR(req);
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto error;
         }
         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
@@ -2131,9 +2136,9 @@ int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
         if (IS_ERR(req))
                 return PTR_ERR(req);
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto error;
         }
         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
@@ -2162,11 +2167,11 @@ int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
         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);
+        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);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto error;
         }
         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
@@ -2192,9 +2197,9 @@ int p9_client_readlink(struct p9_fid *fid, char **target)
         if (IS_ERR(req))
                 return PTR_ERR(req);
 
-        err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
+        err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
         if (err) {
-                trace_9p_protocol_dump(clnt, req->rc);
+                trace_9p_protocol_dump(clnt, &req->rc);
                 goto error;
         }
         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index e2ef3c782c53..51615c0fb744 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -354,7 +354,7 @@ static void p9_read_work(struct work_struct *work)
                         goto error;
                 }
 
-                if (m->req->rc == NULL) {
+                if (!m->req->rc.sdata) {
                         p9_debug(P9_DEBUG_ERROR,
                                  "No recv fcall for tag %d (req %p), disconnecting!\n",
                                  m->rc.tag, m->req);
@@ -362,7 +362,7 @@ static void p9_read_work(struct work_struct *work)
                         err = -EIO;
                         goto error;
                 }
-                m->rc.sdata = (char *)m->req->rc + sizeof(struct p9_fcall);
+                m->rc.sdata = m->req->rc.sdata;
                 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
                 m->rc.capacity = m->rc.size;
         }
@@ -372,7 +372,7 @@ static void p9_read_work(struct work_struct *work)
          */
         if ((m->req) && (m->rc.offset == m->rc.capacity)) {
                 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
-                m->req->rc->size = m->rc.offset;
+                m->req->rc.size = m->rc.offset;
                 spin_lock(&m->client->lock);
                 if (m->req->status != REQ_STATUS_ERROR)
                         status = REQ_STATUS_RCVD;
@@ -469,8 +469,8 @@ static void p9_write_work(struct work_struct *work)
                 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
                 list_move_tail(&req->req_list, &m->req_list);
 
-                m->wbuf = req->tc->sdata;
-                m->wsize = req->tc->size;
+                m->wbuf = req->tc.sdata;
+                m->wsize = req->tc.size;
                 m->wpos = 0;
                 spin_unlock(&m->client->lock);
         }
@@ -663,7 +663,7 @@ static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
         struct p9_conn *m = &ts->conn;
 
         p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
-                 m, current, req->tc, req->tc->id);
+                 m, current, &req->tc, req->tc.id);
         if (m->err < 0)
                 return m->err;
 
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index b513cffeeb3c..5b0cda1aaa7a 100644
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -122,7 +122,7 @@ struct p9_rdma_context {
         dma_addr_t busa;
         union {
                 struct p9_req_t *req;
-                struct p9_fcall *rc;
+                struct p9_fcall rc;
         };
 };
 
@@ -320,8 +320,8 @@ recv_done(struct ib_cq *cq, struct ib_wc *wc)
         if (wc->status != IB_WC_SUCCESS)
                 goto err_out;
 
-        c->rc->size = wc->byte_len;
-        err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
+        c->rc.size = wc->byte_len;
+        err = p9_parse_header(&c->rc, NULL, NULL, &tag, 1);
         if (err)
                 goto err_out;
 
@@ -331,12 +331,13 @@ recv_done(struct ib_cq *cq, struct ib_wc *wc)
 
         /* Check that we have not yet received a reply for this request.
          */
-        if (unlikely(req->rc)) {
+        if (unlikely(req->rc.sdata)) {
                 pr_err("Duplicate reply for request %d", tag);
                 goto err_out;
         }
 
-        req->rc = c->rc;
+        req->rc.size = c->rc.size;
+        req->rc.sdata = c->rc.sdata;
         p9_client_cb(client, req, REQ_STATUS_RCVD);
 
  out:
@@ -361,7 +362,7 @@ send_done(struct ib_cq *cq, struct ib_wc *wc)
                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
 
         ib_dma_unmap_single(rdma->cm_id->device,
-                            c->busa, c->req->tc->size,
+                            c->busa, c->req->tc.size,
                             DMA_TO_DEVICE);
         up(&rdma->sq_sem);
         kfree(c);
@@ -401,7 +402,7 @@ post_recv(struct p9_client *client, struct p9_rdma_context *c)
         struct ib_sge sge;
 
         c->busa = ib_dma_map_single(rdma->cm_id->device,
-                                    c->rc->sdata, client->msize,
+                                    c->rc.sdata, client->msize,
                                     DMA_FROM_DEVICE);
         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
                 goto error;
@@ -443,9 +444,9 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
          **/
         if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
                 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
-                        /* Got one ! */
-                        kfree(req->rc);
-                        req->rc = NULL;
+                        /* Got one! */
+                        p9_fcall_fini(&req->rc);
+                        req->rc.sdata = NULL;
                         goto dont_need_post_recv;
                 } else {
                         /* We raced and lost. */
@@ -459,7 +460,7 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
                 err = -ENOMEM;
                 goto recv_error;
         }
-        rpl_context->rc = req->rc;
+        rpl_context->rc.sdata = req->rc.sdata;
 
         /*
          * Post a receive buffer for this request. We need to ensure
@@ -479,7 +480,7 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
                 goto recv_error;
         }
         /* remove posted receive buffer from request structure */
-        req->rc = NULL;
+        req->rc.sdata = NULL;
 
 dont_need_post_recv:
         /* Post the request */
@@ -491,7 +492,7 @@ dont_need_post_recv:
         c->req = req;
 
         c->busa = ib_dma_map_single(rdma->cm_id->device,
-                                    c->req->tc->sdata, c->req->tc->size,
+                                    c->req->tc.sdata, c->req->tc.size,
                                     DMA_TO_DEVICE);
         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
                 err = -EIO;
@@ -501,7 +502,7 @@ dont_need_post_recv:
         c->cqe.done = send_done;
 
         sge.addr = c->busa;
-        sge.length = c->req->tc->size;
+        sge.length = c->req->tc.size;
         sge.lkey = rdma->pd->local_dma_lkey;
 
         wr.next = NULL;
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 7728b0acde09..3dd6ce1c0f2d 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -155,7 +155,7 @@ static void req_done(struct virtqueue *vq)
                 }
 
                 if (len) {
-                        req->rc->size = len;
+                        req->rc.size = len;
                         p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
                 }
         }
@@ -273,12 +273,12 @@ req_retry:
         out_sgs = in_sgs = 0;
         /* Handle out VirtIO ring buffers */
         out = pack_sg_list(chan->sg, 0,
-                           VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
+                           VIRTQUEUE_NUM, req->tc.sdata, req->tc.size);
         if (out)
                 sgs[out_sgs++] = chan->sg;
 
         in = pack_sg_list(chan->sg, out,
-                          VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
+                          VIRTQUEUE_NUM, req->rc.sdata, req->rc.capacity);
         if (in)
                 sgs[out_sgs + in_sgs++] = chan->sg + out;
 
@@ -416,15 +416,15 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
                 out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
                 if (n != outlen) {
                         __le32 v = cpu_to_le32(n);
-                        memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
+                        memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4);
                         outlen = n;
                 }
                 /* The size field of the message must include the length of the
                  * header and the length of the data.  We didn't actually know
                  * the length of the data until this point so add it in now.
                  */
-                sz = cpu_to_le32(req->tc->size + outlen);
-                memcpy(&req->tc->sdata[0], &sz, sizeof(sz));
+                sz = cpu_to_le32(req->tc.size + outlen);
+                memcpy(&req->tc.sdata[0], &sz, sizeof(sz));
         } else if (uidata) {
                 int n = p9_get_mapped_pages(chan, &in_pages, uidata,
                                             inlen, &offs, &need_drop);
@@ -433,7 +433,7 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
                 in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
                 if (n != inlen) {
                         __le32 v = cpu_to_le32(n);
-                        memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
+                        memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4);
                         inlen = n;
                 }
         }
@@ -445,7 +445,7 @@ req_retry_pinned:
 
         /* out data */
         out = pack_sg_list(chan->sg, 0,
-                           VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
+                           VIRTQUEUE_NUM, req->tc.sdata, req->tc.size);
 
         if (out)
                 sgs[out_sgs++] = chan->sg;
@@ -464,7 +464,7 @@ req_retry_pinned:
          * alloced memory and payload onto the user buffer.
          */
         in = pack_sg_list(chan->sg, out,
-                          VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
+                          VIRTQUEUE_NUM, req->rc.sdata, in_hdr_len);
         if (in)
                 sgs[out_sgs + in_sgs++] = chan->sg + out;
 
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index 843cb823d9b9..782a07f2ad0c 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -141,7 +141,7 @@ static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req)
         struct xen_9pfs_front_priv *priv = NULL;
         RING_IDX cons, prod, masked_cons, masked_prod;
         unsigned long flags;
-        u32 size = p9_req->tc->size;
+        u32 size = p9_req->tc.size;
         struct xen_9pfs_dataring *ring;
         int num;
 
@@ -154,7 +154,7 @@ static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req)
         if (!priv || priv->client != client)
                 return -EINVAL;
 
-        num = p9_req->tc->tag % priv->num_rings;
+        num = p9_req->tc.tag % priv->num_rings;
         ring = &priv->rings[num];
 
 again:
@@ -176,7 +176,7 @@ again:
         masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE);
         masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE);
 
-        xen_9pfs_write_packet(ring->data.out, p9_req->tc->sdata, size,
+        xen_9pfs_write_packet(ring->data.out, p9_req->tc.sdata, size,
                               &masked_prod, masked_cons, XEN_9PFS_RING_SIZE);
 
         p9_req->status = REQ_STATUS_SENT;
@@ -229,12 +229,12 @@ static void p9_xen_response(struct work_struct *work)
                         continue;
                 }
 
-                memcpy(req->rc, &h, sizeof(h));
-                req->rc->offset = 0;
+                memcpy(&req->rc, &h, sizeof(h));
+                req->rc.offset = 0;
 
                 masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE);
                 /* Then, read the whole packet (including the header) */
-                xen_9pfs_read_packet(req->rc->sdata, ring->data.in, h.size,
+                xen_9pfs_read_packet(req->rc.sdata, ring->data.in, h.size,
                                      masked_prod, &masked_cons,
                                      XEN_9PFS_RING_SIZE);