fuse: use iov_iter_get_pages() for non-splice path

store reference to iter instead of that to iovec

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 17 insertions, 24 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 89bf9df2d7ff..c8b68ab2e574 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -710,28 +710,26 @@ struct fuse_copy_state {
         struct fuse_conn *fc;
         int write;
         struct fuse_req *req;
-        const struct iovec *iov;
+        struct iov_iter *iter;
         struct pipe_buffer *pipebufs;
         struct pipe_buffer *currbuf;
         struct pipe_inode_info *pipe;
         unsigned long nr_segs;
-        unsigned long seglen;
-        unsigned long addr;
         struct page *pg;
         unsigned len;
         unsigned offset;
         unsigned move_pages:1;
 };
 
-static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
+static void fuse_copy_init(struct fuse_copy_state *cs,
+                           struct fuse_conn *fc,
                            int write,
-                           const struct iovec *iov, unsigned long nr_segs)
+                           struct iov_iter *iter)
 {
         memset(cs, 0, sizeof(*cs));
         cs->fc = fc;
         cs->write = write;
-        cs->iov = iov;
-        cs->nr_segs = nr_segs;
+        cs->iter = iter;
 }
 
 /* Unmap and put previous page of userspace buffer */
@@ -799,22 +797,16 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
                         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, &page);
+                size_t off;
+                err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
                 if (err < 0)
                         return err;
-                BUG_ON(err != 1);
+                BUG_ON(!err);
+                cs->len = err;
+                cs->offset = off;
                 cs->pg = page;
-                cs->offset = cs->addr % PAGE_SIZE;
-                cs->len = min(PAGE_SIZE - cs->offset, cs->seglen);
-                cs->seglen -= cs->len;
-                cs->addr += cs->len;
+                cs->offset = off;
+                iov_iter_advance(cs->iter, err);
         }
 
         return lock_request(cs->fc, cs->req);
@@ -1374,7 +1366,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
         if (!iter_is_iovec(to))
                 return -EINVAL;
 
-        fuse_copy_init(&cs, fc, 1, to->iov, to->nr_segs);
+        fuse_copy_init(&cs, fc, 1, to);
 
         return fuse_dev_do_read(fc, file, &cs, iov_iter_count(to));
 }
@@ -1396,7 +1388,7 @@ static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
         if (!bufs)
                 return -ENOMEM;
 
-        fuse_copy_init(&cs, fc, 1, NULL, 0);
+        fuse_copy_init(&cs, fc, 1, NULL);
         cs.pipebufs = bufs;
         cs.pipe = pipe;
         ret = fuse_dev_do_read(fc, in, &cs, len);
@@ -1982,7 +1974,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
         if (!iter_is_iovec(from))
                 return -EINVAL;
 
-        fuse_copy_init(&cs, fc, 0, from->iov, from->nr_segs);
+        fuse_copy_init(&cs, fc, 0, from);
 
         return fuse_dev_do_write(fc, &cs, iov_iter_count(from));
 }
@@ -2047,8 +2039,9 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
         }
         pipe_unlock(pipe);
 
-        fuse_copy_init(&cs, fc, 0, NULL, nbuf);
+        fuse_copy_init(&cs, fc, 0, NULL);
         cs.pipebufs = bufs;
+        cs.nr_segs = nbuf;
         cs.pipe = pipe;
 
         if (flags & SPLICE_F_MOVE)