Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block

[sfrench/cifs-2.6.git] / fs / splice.c

diff --git a/fs/splice.c b/fs/splice.c
index b06846f1e6ee2a2d612cd772753b239c0b3a5dc7..5dbce4dcc1a7df61559eb19b0ba3c471afc1debe 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -662,12 +662,14 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 
                /* build the vector */
                left = sd.total_len;
-               for (n = 0; !pipe_empty(head, tail) && left && n < nbufs; tail++, n++) {
+               for (n = 0; !pipe_empty(head, tail) && left && n < nbufs; tail++) {
                        struct pipe_buffer *buf = &pipe->bufs[tail & mask];
                        size_t this_len = buf->len;
 
-                       if (this_len > left)
-                               this_len = left;
+                       /* zero-length bvecs are not supported, skip them */
+                       if (!this_len)
+                               continue;
+                       this_len = min(this_len, left);
 
                        ret = pipe_buf_confirm(pipe, buf);
                        if (unlikely(ret)) {
@@ -680,6 +682,7 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
                        array[n].bv_len = this_len;
                        array[n].bv_offset = buf->offset;
                        left -= this_len;
+                       n++;
                }
 
                iov_iter_bvec(&from, WRITE, array, n, sd.total_len - left);