1 files changed, 79 insertions, 58 deletions

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 36a1a739ad68..e62bcbbabb5e 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -217,15 +217,15 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
  * @start: which segment of the sg_list to start at
  * @pdata: a list of pages to add into sg.
  * @nr_pages: number of pages to pack into the scatter/gather list
- * @data: data to pack into scatter/gather list
+ * @offs: amount of data in the beginning of first page _not_ to pack
  * @count: amount of data to pack into the scatter/gather list
  */
 static int
 pack_sg_list_p(struct scatterlist *sg, int start, int limit,
-               struct page **pdata, int nr_pages, char *data, int count)
+               struct page **pdata, int nr_pages, size_t offs, int count)
 {
         int i = 0, s;
-        int data_off;
+        int data_off = offs;
         int index = start;
 
         BUG_ON(nr_pages > (limit - start));
@@ -233,16 +233,14 @@ pack_sg_list_p(struct scatterlist *sg, int start, int limit,
          * if the first page doesn't start at
          * page boundary find the offset
          */
-        data_off = offset_in_page(data);
         while (nr_pages) {
-                s = rest_of_page(data);
+                s = PAGE_SIZE - data_off;
                 if (s > count)
                         s = count;
                 /* Make sure we don't terminate early. */
                 sg_unmark_end(&sg[index]);
                 sg_set_page(&sg[index++], pdata[i++], s, data_off);
                 data_off = 0;
-                data += s;
                 count -= s;
                 nr_pages--;
         }
@@ -314,11 +312,20 @@ req_retry:
 }
 
 static int p9_get_mapped_pages(struct virtio_chan *chan,
-                               struct page **pages, char *data,
-                               int nr_pages, int write, int kern_buf)
+                               struct page ***pages,
+                               struct iov_iter *data,
+                               int count,
+                               size_t *offs,
+                               int *need_drop)
 {
+        int nr_pages;
         int err;
-        if (!kern_buf) {
+
+        if (!iov_iter_count(data))
+                return 0;
+
+        if (!(data->type & ITER_KVEC)) {
+                int n;
                 /*
                  * We allow only p9_max_pages pinned. We wait for the
                  * Other zc request to finish here
@@ -329,26 +336,49 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
                         if (err == -ERESTARTSYS)
                                 return err;
                 }
-                err = p9_payload_gup(data, &nr_pages, pages, write);
-                if (err < 0)
-                        return err;
+                n = iov_iter_get_pages_alloc(data, pages, count, offs);
+                if (n < 0)
+                        return n;
+                *need_drop = 1;
+                nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE);
                 atomic_add(nr_pages, &vp_pinned);
+                return n;
         } else {
                 /* kernel buffer, no need to pin pages */
-                int s, index = 0;
-                int count = nr_pages;
-                while (nr_pages) {
-                        s = rest_of_page(data);
-                        if (is_vmalloc_addr(data))
-                                pages[index++] = vmalloc_to_page(data);
+                int index;
+                size_t len;
+                void *p;
+
+                /* we'd already checked that it's non-empty */
+                while (1) {
+                        len = iov_iter_single_seg_count(data);
+                        if (likely(len)) {
+                                p = data->kvec->iov_base + data->iov_offset;
+                                break;
+                        }
+                        iov_iter_advance(data, 0);
+                }
+                if (len > count)
+                        len = count;
+
+                nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) -
+                           (unsigned long)p / PAGE_SIZE;
+
+                *pages = kmalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
+                if (!*pages)
+                        return -ENOMEM;
+
+                *need_drop = 0;
+                p -= (*offs = (unsigned long)p % PAGE_SIZE);
+                for (index = 0; index < nr_pages; index++) {
+                        if (is_vmalloc_addr(p))
+                                (*pages)[index] = vmalloc_to_page(p);
                         else
-                                pages[index++] = kmap_to_page(data);
-                        data += s;
-                        nr_pages--;
+                                (*pages)[index] = kmap_to_page(p);
+                        p += PAGE_SIZE;
                 }
-                nr_pages = count;
+                return len;
         }
-        return nr_pages;
 }
 
 /**
@@ -364,8 +394,8 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
  */
 static int
 p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
-                     char *uidata, char *uodata, int inlen,
-                     int outlen, int in_hdr_len, int kern_buf)
+                     struct iov_iter *uidata, struct iov_iter *uodata,
+                     int inlen, int outlen, int in_hdr_len)
 {
         int in, out, err, out_sgs, in_sgs;
         unsigned long flags;
@@ -373,41 +403,32 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
         struct page **in_pages = NULL, **out_pages = NULL;
         struct virtio_chan *chan = client->trans;
         struct scatterlist *sgs[4];
+        size_t offs;
+        int need_drop = 0;
 
         p9_debug(P9_DEBUG_TRANS, "virtio request\n");
 
         if (uodata) {
-                out_nr_pages = p9_nr_pages(uodata, outlen);
-                out_pages = kmalloc(sizeof(struct page *) * out_nr_pages,
-                                    GFP_NOFS);
-                if (!out_pages) {
-                        err = -ENOMEM;
-                        goto err_out;
-                }
-                out_nr_pages = p9_get_mapped_pages(chan, out_pages, uodata,
-                                                   out_nr_pages, 0, kern_buf);
-                if (out_nr_pages < 0) {
-                        err = out_nr_pages;
-                        kfree(out_pages);
-                        out_pages = NULL;
-                        goto err_out;
+                int n = p9_get_mapped_pages(chan, &out_pages, uodata,
+                                            outlen, &offs, &need_drop);
+                if (n < 0)
+                        return n;
+                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);
+                        outlen = n;
                 }
-        }
-        if (uidata) {
-                in_nr_pages = p9_nr_pages(uidata, inlen);
-                in_pages = kmalloc(sizeof(struct page *) * in_nr_pages,
-                                   GFP_NOFS);
-                if (!in_pages) {
-                        err = -ENOMEM;
-                        goto err_out;
-                }
-                in_nr_pages = p9_get_mapped_pages(chan, in_pages, uidata,
-                                                  in_nr_pages, 1, kern_buf);
-                if (in_nr_pages < 0) {
-                        err = in_nr_pages;
-                        kfree(in_pages);
-                        in_pages = NULL;
-                        goto err_out;
+        } else if (uidata) {
+                int n = p9_get_mapped_pages(chan, &in_pages, uidata,
+                                            inlen, &offs, &need_drop);
+                if (n < 0)
+                        return n;
+                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);
+                        inlen = n;
                 }
         }
         req->status = REQ_STATUS_SENT;
@@ -426,7 +447,7 @@ req_retry_pinned:
         if (out_pages) {
                 sgs[out_sgs++] = chan->sg + out;
                 out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
-                                      out_pages, out_nr_pages, uodata, outlen);
+                                      out_pages, out_nr_pages, offs, outlen);
         }
                 
         /*
@@ -444,7 +465,7 @@ req_retry_pinned:
         if (in_pages) {
                 sgs[out_sgs + in_sgs++] = chan->sg + out + in;
                 in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
-                                     in_pages, in_nr_pages, uidata, inlen);
+                                     in_pages, in_nr_pages, offs, inlen);
         }
 
         BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
@@ -478,7 +499,7 @@ req_retry_pinned:
          * Non kernel buffers are pinned, unpin them
          */
 err_out:
-        if (!kern_buf) {
+        if (need_drop) {
                 if (in_pages) {
                         p9_release_pages(in_pages, in_nr_pages);
                         atomic_sub(in_nr_pages, &vp_pinned);