Fix nvme initiator handling when not enabled.

[karo-tx-linux.git] / lib / iov_iter.c

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 25f57230380104f419257ea43c1cd3d2e31d7e65..e68604ae3cedf41ce98bc06de2142629fa115cbd 100644 (file)
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -730,43 +730,50 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
 }
 EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
 
+static inline void pipe_truncate(struct iov_iter *i)
+{
+       struct pipe_inode_info *pipe = i->pipe;
+       if (pipe->nrbufs) {
+               size_t off = i->iov_offset;
+               int idx = i->idx;
+               int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1);
+               if (off) {
+                       pipe->bufs[idx].len = off - pipe->bufs[idx].offset;
+                       idx = next_idx(idx, pipe);
+                       nrbufs++;
+               }
+               while (pipe->nrbufs > nrbufs) {
+                       pipe_buf_release(pipe, &pipe->bufs[idx]);
+                       idx = next_idx(idx, pipe);
+                       pipe->nrbufs--;
+               }
+       }
+}
+
 static void pipe_advance(struct iov_iter *i, size_t size)
 {
        struct pipe_inode_info *pipe = i->pipe;
-       struct pipe_buffer *buf;
-       int idx = i->idx;
-       size_t off = i->iov_offset, orig_sz;
-       
        if (unlikely(i->count < size))
                size = i->count;
-       orig_sz = size;
-
        if (size) {
+               struct pipe_buffer *buf;
+               size_t off = i->iov_offset, left = size;
+               int idx = i->idx;
                if (off) /* make it relative to the beginning of buffer */
-                       size += off - pipe->bufs[idx].offset;
+                       left += off - pipe->bufs[idx].offset;
                while (1) {
                        buf = &pipe->bufs[idx];
-                       if (size <= buf->len)
+                       if (left <= buf->len)
                                break;
-                       size -= buf->len;
+                       left -= buf->len;
                        idx = next_idx(idx, pipe);
                }
-               buf->len = size;
                i->idx = idx;
-               off = i->iov_offset = buf->offset + size;
-       }
-       if (off)
-               idx = next_idx(idx, pipe);
-       if (pipe->nrbufs) {
-               int unused = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
-               /* [curbuf,unused) is in use.  Free [idx,unused) */
-               while (idx != unused) {
-                       pipe_buf_release(pipe, &pipe->bufs[idx]);
-                       idx = next_idx(idx, pipe);
-                       pipe->nrbufs--;
-               }
+               i->iov_offset = buf->offset + left;
        }
-       i->count -= orig_sz;
+       i->count -= size;
+       /* ... and discard everything past that point */
+       pipe_truncate(i);
 }
 
 void iov_iter_advance(struct iov_iter *i, size_t size)
@@ -826,6 +833,7 @@ void iov_iter_pipe(struct iov_iter *i, int direction,
                        size_t count)
 {
        BUG_ON(direction != ITER_PIPE);
+       WARN_ON(pipe->nrbufs == pipe->buffers);
        i->type = direction;
        i->pipe = pipe;
        i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);