vserver 2.0 rc7

[linux-2.6.git] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 13db326..25aa09f 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -224,6 +224,7 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
        int do_wakeup;
        struct iovec *iov = (struct iovec *)_iov;
        size_t total_len;
+       ssize_t chars;
 
        total_len = iov_length(iov, nr_segs);
        /* Null write succeeds. */
@@ -242,24 +243,26 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
        }
 
        /* We try to merge small writes */
-       if (info->nrbufs && total_len < PAGE_SIZE) {
+       chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */
+       if (info->nrbufs && chars != 0) {
                int lastbuf = (info->curbuf + info->nrbufs - 1) & (PIPE_BUFFERS-1);
                struct pipe_buffer *buf = info->bufs + lastbuf;
                struct pipe_buf_operations *ops = buf->ops;
                int offset = buf->offset + buf->len;
-               if (ops->can_merge && offset + total_len <= PAGE_SIZE) {
+               if (ops->can_merge && offset + chars <= PAGE_SIZE) {
                        void *addr = ops->map(filp, info, buf);
-                       int error = pipe_iov_copy_from_user(offset + addr, iov, total_len);
+                       int error = pipe_iov_copy_from_user(offset + addr, iov, chars);
                        ops->unmap(info, buf);
                        ret = error;
                        do_wakeup = 1;
                        if (error)
                                goto out;
-                       buf->len += total_len;
-                       ret = total_len;
-                       goto out;
+                       buf->len += chars;
+                       total_len -= chars;
+                       ret = chars;
+                       if (!total_len)
+                               goto out;
                }
-                       
        }
 
        for (;;) {
@@ -271,7 +274,6 @@ pipe_writev(struct file *filp, const struct iovec *_iov,
                }
                bufs = info->nrbufs;
                if (bufs < PIPE_BUFFERS) {
-                       ssize_t chars;
                        int newbuf = (info->curbuf + bufs) & (PIPE_BUFFERS-1);
                        struct pipe_buffer *buf = info->bufs + newbuf;
                        struct page *page = info->tmp_page;