2 files changed, 148 insertions, 32 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 4623018e104a..2795045484ee 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -16,6 +16,7 @@
 #include <linux/pagemap.h>
 #include <linux/file.h>
 #include <linux/slab.h>
+#include <linux/pipe_fs_i.h>
 
 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
 
@@ -498,6 +499,9 @@ struct fuse_copy_state {
         int write;
         struct fuse_req *req;
         const struct iovec *iov;
+        struct pipe_buffer *pipebufs;
+        struct pipe_buffer *currbuf;
+        struct pipe_inode_info *pipe;
         unsigned long nr_segs;
         unsigned long seglen;
         unsigned long addr;
@@ -522,7 +526,14 @@ static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
 /* Unmap and put previous page of userspace buffer */
 static void fuse_copy_finish(struct fuse_copy_state *cs)
 {
-        if (cs->mapaddr) {
+        if (cs->currbuf) {
+                struct pipe_buffer *buf = cs->currbuf;
+
+                buf->ops->unmap(cs->pipe, buf, cs->mapaddr);
+
+                cs->currbuf = NULL;
+                cs->mapaddr = NULL;
+        } else if (cs->mapaddr) {
                 kunmap_atomic(cs->mapaddr, KM_USER0);
                 if (cs->write) {
                         flush_dcache_page(cs->pg);
@@ -544,23 +555,39 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
 
         unlock_request(cs->fc, cs->req);
         fuse_copy_finish(cs);
-        if (!cs->seglen) {
+        if (cs->pipebufs) {
+                struct pipe_buffer *buf = cs->pipebufs;
+
+                err = buf->ops->confirm(cs->pipe, buf);
+                if (err)
+                        return err;
+
                 BUG_ON(!cs->nr_segs);
-                cs->seglen = cs->iov[0].iov_len;
-                cs->addr = (unsigned long) cs->iov[0].iov_base;
-                cs->iov++;
+                cs->currbuf = buf;
+                cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
+                cs->len = buf->len;
+                cs->buf = cs->mapaddr + buf->offset;
+                cs->pipebufs++;
                 cs->nr_segs--;
+        } else {
+                if (!cs->seglen) {
+                        BUG_ON(!cs->nr_segs);
+                        cs->seglen = cs->iov[0].iov_len;
+                        cs->addr = (unsigned long) cs->iov[0].iov_base;
+                        cs->iov++;
+                        cs->nr_segs--;
+                }
+                err = get_user_pages_fast(cs->addr, 1, cs->write, &cs->pg);
+                if (err < 0)
+                        return err;
+                BUG_ON(err != 1);
+                offset = cs->addr % PAGE_SIZE;
+                cs->mapaddr = kmap_atomic(cs->pg, KM_USER0);
+                cs->buf = cs->mapaddr + offset;
+                cs->len = min(PAGE_SIZE - offset, cs->seglen);
+                cs->seglen -= cs->len;
+                cs->addr += cs->len;
         }
-        err = get_user_pages_fast(cs->addr, 1, cs->write, &cs->pg);
-        if (err < 0)
-                return err;
-        BUG_ON(err != 1);
-        offset = cs->addr % PAGE_SIZE;
-        cs->mapaddr = kmap_atomic(cs->pg, KM_USER0);
-        cs->buf = cs->mapaddr + offset;
-        cs->len = min(PAGE_SIZE - offset, cs->seglen);
-        cs->seglen -= cs->len;
-        cs->addr += cs->len;
 
         return lock_request(cs->fc, cs->req);
 }
@@ -984,23 +1011,17 @@ static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
  * it from the list and copy the rest of the buffer to the request.
  * The request is finished by calling request_end()
  */
-static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
-                               unsigned long nr_segs, loff_t pos)
+static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
+                                 struct fuse_copy_state *cs, size_t nbytes)
 {
         int err;
-        size_t nbytes = iov_length(iov, nr_segs);
         struct fuse_req *req;
         struct fuse_out_header oh;
-        struct fuse_copy_state cs;
-        struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
-        if (!fc)
-                return -EPERM;
 
-        fuse_copy_init(&cs, fc, 0, NULL, iov, nr_segs);
         if (nbytes < sizeof(struct fuse_out_header))
                 return -EINVAL;
 
-        err = fuse_copy_one(&cs, &oh, sizeof(oh));
+        err = fuse_copy_one(cs, &oh, sizeof(oh));
         if (err)
                 goto err_finish;
 
@@ -1013,7 +1034,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
          * and error contains notification code.
          */
         if (!oh.unique) {
-                err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), &cs);
+                err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
                 return err ? err : nbytes;
         }
 
@@ -1032,7 +1053,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
 
         if (req->aborted) {
                 spin_unlock(&fc->lock);
-                fuse_copy_finish(&cs);
+                fuse_copy_finish(cs);
                 spin_lock(&fc->lock);
                 request_end(fc, req);
                 return -ENOENT;
@@ -1049,7 +1070,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
                         queue_interrupt(fc, req);
 
                 spin_unlock(&fc->lock);
-                fuse_copy_finish(&cs);
+                fuse_copy_finish(cs);
                 return nbytes;
         }
 
@@ -1057,11 +1078,11 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
         list_move(&req->list, &fc->io);
         req->out.h = oh;
         req->locked = 1;
-        cs.req = req;
+        cs->req = req;
         spin_unlock(&fc->lock);
 
-        err = copy_out_args(&cs, &req->out, nbytes);
-        fuse_copy_finish(&cs);
+        err = copy_out_args(cs, &req->out, nbytes);
+        fuse_copy_finish(cs);
 
         spin_lock(&fc->lock);
         req->locked = 0;
@@ -1077,10 +1098,101 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
  err_unlock:
         spin_unlock(&fc->lock);
  err_finish:
-        fuse_copy_finish(&cs);
+        fuse_copy_finish(cs);
         return err;
 }
 
+static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
+                              unsigned long nr_segs, loff_t pos)
+{
+        struct fuse_copy_state cs;
+        struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
+        if (!fc)
+                return -EPERM;
+
+        fuse_copy_init(&cs, fc, 0, NULL, iov, nr_segs);
+
+        return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
+}
+
+static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
+                                     struct file *out, loff_t *ppos,
+                                     size_t len, unsigned int flags)
+{
+        unsigned nbuf;
+        unsigned idx;
+        struct pipe_buffer *bufs;
+        struct fuse_copy_state cs;
+        struct fuse_conn *fc;
+        size_t rem;
+        ssize_t ret;
+
+        fc = fuse_get_conn(out);
+        if (!fc)
+                return -EPERM;
+
+        bufs = kmalloc(pipe->buffers * sizeof (struct pipe_buffer), GFP_KERNEL);
+        if (!bufs)
+                return -ENOMEM;
+
+        pipe_lock(pipe);
+        nbuf = 0;
+        rem = 0;
+        for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
+                rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
+
+        ret = -EINVAL;
+        if (rem < len) {
+                pipe_unlock(pipe);
+                goto out;
+        }
+
+        rem = len;
+        while (rem) {
+                struct pipe_buffer *ibuf;
+                struct pipe_buffer *obuf;
+
+                BUG_ON(nbuf >= pipe->buffers);
+                BUG_ON(!pipe->nrbufs);
+                ibuf = &pipe->bufs[pipe->curbuf];
+                obuf = &bufs[nbuf];
+
+                if (rem >= ibuf->len) {
+                        *obuf = *ibuf;
+                        ibuf->ops = NULL;
+                        pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
+                        pipe->nrbufs--;
+                } else {
+                        ibuf->ops->get(pipe, ibuf);
+                        *obuf = *ibuf;
+                        obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
+                        obuf->len = rem;
+                        ibuf->offset += obuf->len;
+                        ibuf->len -= obuf->len;
+                }
+                nbuf++;
+                rem -= obuf->len;
+        }
+        pipe_unlock(pipe);
+
+        memset(&cs, 0, sizeof(struct fuse_copy_state));
+        cs.fc = fc;
+        cs.write = 0;
+        cs.pipebufs = bufs;
+        cs.nr_segs = nbuf;
+        cs.pipe = pipe;
+
+        ret = fuse_dev_do_write(fc, &cs, len);
+
+        for (idx = 0; idx < nbuf; idx++) {
+                struct pipe_buffer *buf = &bufs[idx];
+                buf->ops->release(pipe, buf);
+        }
+out:
+        kfree(bufs);
+        return ret;
+}
+
 static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
 {
         unsigned mask = POLLOUT | POLLWRNORM;
@@ -1224,6 +1336,7 @@ const struct file_operations fuse_dev_operations = {
         .aio_read       = fuse_dev_read,
         .write          = do_sync_write,
         .aio_write      = fuse_dev_write,
+        .splice_write   = fuse_dev_splice_write,
         .poll           = fuse_dev_poll,
         .release        = fuse_dev_release,
         .fasync         = fuse_dev_fasync,
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 3e2925a34bf0..88e0eb596919 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -34,6 +34,9 @@
  * 7.13
  *  - make max number of background requests and congestion threshold
  *    tunables
+ *
+ * 7.14
+ *  - add splice support to fuse device
  */
 
 #ifndef _LINUX_FUSE_H
@@ -65,7 +68,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 13
+#define FUSE_KERNEL_MINOR_VERSION 14
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1