[CRIU] [PATCH 04/11] pagemap: Enqueue iovec to arbitrary list

[Pavel Emelyanov]

We currently can batch pagemap entries into page-read list, but will
need to queue them into per-pstree_entry one.

Signed-off-by: Pavel Emelyanov <xemul at virtuozzo.com>
---
 criu/include/pagemap.h |  3 +++
 criu/pagemap.c         | 19 ++++++++++---------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/criu/include/pagemap.h b/criu/include/pagemap.h
index b23ec3a..aa3c4aa 100644
--- a/criu/include/pagemap.h
+++ b/criu/include/pagemap.h
@@ -104,6 +104,9 @@ extern int open_page_read(int pid, struct page_read *, int pr_flags);
 extern int open_page_read_at(int dfd, int pid, struct page_read *pr,
 		int pr_flags);
 
+int pagemap_enqueue_iovec(struct page_read *pr, void *buf,
+			      unsigned long len, struct list_head *to);
+
 /*
  * Create a shallow copy of page_read object.
  * The new object shares the pagemap structures with the original, but
diff --git a/criu/pagemap.c b/criu/pagemap.c
index 2cf91e3..dcc1332 100644
--- a/criu/pagemap.c
+++ b/criu/pagemap.c
@@ -279,7 +279,8 @@ static int read_local_page(struct page_read *pr, unsigned long vaddr,
 	return 0;
 }
 
-static int enqueue_async_iov(struct page_read *pr, unsigned long len, void *buf)
+static int enqueue_async_iov(struct page_read *pr, void *buf,
+		unsigned long len, struct list_head *to)
 {
 	struct page_read_iov *pr_iov;
 	struct iovec *iov;
@@ -303,19 +304,19 @@ static int enqueue_async_iov(struct page_read *pr, unsigned long len, void *buf)
 	pr_iov->to = iov;
 	pr_iov->nr = 1;
 
-	list_add_tail(&pr_iov->l, &pr->async);
+	list_add_tail(&pr_iov->l, to);
 
 	return 0;
 }
 
-static int enqueue_async_page(struct page_read *pr, unsigned long vaddr,
-			      unsigned long len, void *buf)
+int pagemap_enqueue_iovec(struct page_read *pr, void *buf,
+			      unsigned long len, struct list_head *to)
 {
 	struct page_read_iov *cur_async = NULL;
 	struct iovec *iov;
 
-	if (!list_empty(&pr->async))
-		cur_async = list_entry(pr->async.prev, struct page_read_iov, l);
+	if (!list_empty(to))
+		cur_async = list_entry(to->prev, struct page_read_iov, l);
 
 	/*
 	 * We don't have any async requests or we have new read
@@ -324,7 +325,7 @@ static int enqueue_async_page(struct page_read *pr, unsigned long vaddr,
 	 * Start the new preadv request here.
 	 */
 	if (!cur_async || pr->pi_off != cur_async->end)
-		return enqueue_async_iov(pr, len, buf);
+		return enqueue_async_iov(pr, buf, len, to);
 
 	/*
 	 * This read is pure continuation of the previous one. Let's
@@ -339,7 +340,7 @@ static int enqueue_async_page(struct page_read *pr, unsigned long vaddr,
 		unsigned int n_iovs = cur_async->nr + 1;
 
 		if (n_iovs >= IOV_MAX)
-			return enqueue_async_iov(pr, len, buf);
+			return enqueue_async_iov(pr, buf, len, to);
 
 		iov = xrealloc(cur_async->to, n_iovs * sizeof(*iov));
 		if (!iov)
@@ -372,7 +373,7 @@ static int maybe_read_page_local(struct page_read *pr, unsigned long vaddr,
 	 * cached read.
 	 */
 	if ((flags & (PR_ASYNC|PR_ASAP)) == PR_ASYNC && !opts.remote)
-		ret = enqueue_async_page(pr, vaddr, len, buf);
+		ret = pagemap_enqueue_iovec(pr, buf, len, &pr->async);
 	else {
 		ret = read_local_page(pr, vaddr, len, buf);
 		if (ret == 0 && pr->io_complete)
-- 
2.1.4