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Diffstat (limited to 'fs/splice.c')
-rw-r--r--fs/splice.c28
1 files changed, 25 insertions, 3 deletions
diff --git a/fs/splice.c b/fs/splice.c
index d4664a297bab..b150493b6fc3 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -141,7 +141,10 @@ static struct pipe_buf_operations page_cache_pipe_buf_ops = {
static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
- return 1;
+ if (!(buf->flags & PIPE_BUF_FLAG_GIFT))
+ return 1;
+
+ return 0;
}
static struct pipe_buf_operations user_page_pipe_buf_ops = {
@@ -186,6 +189,9 @@ static ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
buf->offset = spd->partial[page_nr].offset;
buf->len = spd->partial[page_nr].len;
buf->ops = spd->ops;
+ if (spd->flags & SPLICE_F_GIFT)
+ buf->flags |= PIPE_BUF_FLAG_GIFT;
+
pipe->nrbufs++;
page_nr++;
ret += buf->len;
@@ -1073,7 +1079,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
*/
static int get_iovec_page_array(const struct iovec __user *iov,
unsigned int nr_vecs, struct page **pages,
- struct partial_page *partial)
+ struct partial_page *partial, int aligned)
{
int buffers = 0, error = 0;
@@ -1113,6 +1119,15 @@ static int get_iovec_page_array(const struct iovec __user *iov,
* in the user pages.
*/
off = (unsigned long) base & ~PAGE_MASK;
+
+ /*
+ * If asked for alignment, the offset must be zero and the
+ * length a multiple of the PAGE_SIZE.
+ */
+ error = -EINVAL;
+ if (aligned && (off || len & ~PAGE_MASK))
+ break;
+
npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
if (npages > PIPE_BUFFERS - buffers)
npages = PIPE_BUFFERS - buffers;
@@ -1206,7 +1221,8 @@ static long do_vmsplice(struct file *file, const struct iovec __user *iov,
else if (unlikely(!nr_segs))
return 0;
- spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial);
+ spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial,
+ flags & SPLICE_F_GIFT);
if (spd.nr_pages <= 0)
return spd.nr_pages;
@@ -1314,6 +1330,12 @@ static int link_pipe(struct pipe_inode_info *ipipe,
obuf = opipe->bufs + nbuf;
*obuf = *ibuf;
+ /*
+ * Don't inherit the gift flag, we need to
+ * prevent multiple steals of this page.
+ */
+ obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
+
if (obuf->len > len)
obuf->len = len;