1 files changed, 13 insertions, 6 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index ba1d50369c24..8f39f7b8cef2 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1331,7 +1331,8 @@ EXPORT_SYMBOL_GPL(fuse_direct_io);
 
 static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
                                   const struct iovec *iov,
-                                  unsigned long nr_segs, loff_t *ppos)
+                                  unsigned long nr_segs, loff_t *ppos,
+                                  size_t count)
 {
         ssize_t res;
         struct file *file = io->file;
@@ -1340,8 +1341,7 @@ static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
         if (is_bad_inode(inode))
                 return -EIO;
 
-        res = fuse_direct_io(io, iov, nr_segs, iov_length(iov, nr_segs),
-                             ppos, 0);
+        res = fuse_direct_io(io, iov, nr_segs, count, ppos, 0);
 
         fuse_invalidate_attr(inode);
 
@@ -1353,7 +1353,7 @@ static ssize_t fuse_direct_read(struct file *file, char __user *buf,
 {
         struct fuse_io_priv io = { .async = 0, .file = file };
         struct iovec iov = { .iov_base = buf, .iov_len = count };
-        return __fuse_direct_read(&io, &iov, 1, ppos);
+        return __fuse_direct_read(&io, &iov, 1, ppos, count);
 }
 
 static ssize_t __fuse_direct_write(struct fuse_io_priv *io,
@@ -2369,6 +2369,13 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
         inode = file->f_mapping->host;
         i_size = i_size_read(inode);
 
+        /* optimization for short read */
+        if (rw != WRITE && offset + count > i_size) {
+                if (offset >= i_size)
+                        return 0;
+                count = i_size - offset;
+        }
+
         io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
         if (!io)
                 return -ENOMEM;
@@ -2392,13 +2399,13 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
          * to wait on real async I/O requests, so we must submit this request
          * synchronously.
          */
-        if (!is_sync_kiocb(iocb) && (offset + count > i_size) && rw == WRITE)
+        if (!is_sync_kiocb(iocb) && (offset + count > i_size))
                 io->async = false;
 
         if (rw == WRITE)
                 ret = __fuse_direct_write(io, iov, nr_segs, &pos);
         else
-                ret = __fuse_direct_read(io, iov, nr_segs, &pos);
+                ret = __fuse_direct_read(io, iov, nr_segs, &pos, count);
 
         if (io->async) {
                 fuse_aio_complete(io, ret < 0 ? ret : 0, -1);