[CRIU] [PATCHv2 4/9] shmem: pass anonymous shmem pagemap to add_shmem_area

[Eugene Batalov]

From: Fyodor Bocharov <bocharovfedor at gmail.com>

So we would be able to analyze pagemap bits for each
anonymous shmem page and decide on its dirtiness and usage
by dumpee process.

Signed-off-by: Fyodor Bocharov <fbocharov at yandex.ru>
Signed-off-by: Eugene Batalov <eabatalov89 at gmail.com>
---
 cr-dump.c       |  2 --
 include/shmem.h |  3 ++-
 mem.c           | 29 ++++++++++++++++++-----------
 shmem.c         |  4 +++-
 4 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/cr-dump.c b/cr-dump.c
index 6cafd64..679ea16 100644
--- a/cr-dump.c
+++ b/cr-dump.c
@@ -455,8 +455,6 @@ static int dump_task_mm(pid_t pid, const struct proc_pid_stat *stat,
 			ret = 0;
 		else if (vma_entry_is(vma, VMA_AREA_SYSVIPC))
 			ret = check_sysvipc_map_dump(pid, vma);
-		else if (vma_entry_is(vma, VMA_ANON_SHARED))
-			ret = add_shmem_area(pid, vma);
 		else if (vma_entry_is(vma, VMA_FILE_PRIVATE) ||
 				vma_entry_is(vma, VMA_FILE_SHARED))
 			ret = dump_filemap(pid, vma_area, imgset);
diff --git a/include/shmem.h b/include/shmem.h
index 47dd0fd..066b5c3 100644
--- a/include/shmem.h
+++ b/include/shmem.h
@@ -1,6 +1,7 @@
 #ifndef __CR_SHMEM_H__
 #define __CR_SHMEM_H__
 
+#include "asm/int.h"
 #include "lock.h"
 #include "protobuf/vma.pb-c.h"
 
@@ -10,6 +11,6 @@ extern void show_saved_shmems(void);
 extern int get_shmem_fd(int pid, VmaEntry *vi);
 
 extern int cr_dump_shmem(void);
-extern int add_shmem_area(pid_t pid, VmaEntry *vma);
+extern int add_shmem_area(pid_t pid, VmaEntry *vma, u64 *map);
 
 #endif /* __CR_SHMEM_H__ */
diff --git a/mem.c b/mem.c
index 78cc2fe..c48a22b 100644
--- a/mem.c
+++ b/mem.c
@@ -246,6 +246,7 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
 	struct vma_area *vma_area;
 	struct page_xfer xfer = { .parent = NULL };
 	int ret = -1;
+	unsigned long pmc_size;
 
 	pr_info("\n");
 	pr_info("Dumping pages (type: %d pid: %d)\n", CR_FD_PAGES, ctl->pid.real);
@@ -262,8 +263,9 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
 	 * Step 0 -- prepare
 	 */
 
+	pmc_size = max(vma_area_list->priv_longest, vma_area_list->shared_longest);
 	if (pmc_init(&pmc, ctl->pid.real, &vma_area_list->h,
-			 vma_area_list->priv_longest * PAGE_SIZE))
+			 pmc_size * PAGE_SIZE))
 		return -1;
 
 	ret = -1;
@@ -293,22 +295,27 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
 		u64 off = 0;
 		u64 *map;
 
-		if (!vma_area_is_private(vma_area, kdat.task_size))
+		if (!vma_area_is_private(vma_area, kdat.task_size) &&
+				!vma_area_is(vma_area, VMA_ANON_SHARED))
 			continue;
 
 		map = pmc_get_map(&pmc, vma_area);
 		if (!map)
 			goto out_xfer;
+		if (vma_area_is(vma_area, VMA_ANON_SHARED))
+			ret = add_shmem_area(ctl->pid.real, vma_area->e, map);
+		else {
 again:
-		ret = generate_iovs(vma_area, pp, map, &off, xfer.parent);
-		if (ret == -EAGAIN) {
-			BUG_ON(pp_ret);
-
-			ret = dump_pages(pp, ctl, args, &xfer);
-			if (ret)
-				goto out_xfer;
-			page_pipe_reinit(pp);
-			goto again;
+			ret = generate_iovs(vma_area, pp, map, &off, xfer.parent);
+			if (ret == -EAGAIN) {
+				BUG_ON(pp_ret);
+
+				ret = dump_pages(pp, ctl, args, &xfer);
+				if (ret)
+					goto out_xfer;
+				page_pipe_reinit(pp);
+				goto again;
+			}
 		}
 		if (ret < 0)
 			goto out_xfer;
diff --git a/shmem.c b/shmem.c
index b2900f4..dcbe19f 100644
--- a/shmem.c
+++ b/shmem.c
@@ -12,6 +12,7 @@
 #include "page-xfer.h"
 #include "rst-malloc.h"
 #include "vma.h"
+#include "mem.h"
 
 #include "protobuf.h"
 #include "protobuf/pagemap.pb-c.h"
@@ -301,10 +302,11 @@ static struct shmem_info_dump *shmem_find(struct shmem_info_dump **chain,
 	return NULL;
 }
 
-int add_shmem_area(pid_t pid, VmaEntry *vma)
+int add_shmem_area(pid_t pid, VmaEntry *vma, u64 *map)
 {
 	struct shmem_info_dump *si, **chain;
 	unsigned long size = vma->pgoff + (vma->end - vma->start);
+	(void)map;
 
 	chain = &shmems_hash[vma->shmid % SHMEM_HASH_SIZE];
 	si = shmem_find(chain, vma->shmid);
-- 
1.9.1