[CRIU] [PATCH] criu: dump filemap as soon as possible

[Andrey Vagin]

From: Andrew Vagin <avagin at virtuozzo.com>

A process can have many vma-s and we can hit rlimit for files.

I suggest to dump vma files as soon as possible and close them.

https://jira.sw.ru/browse/PSBM-46355

Cc: Cyrill Gorcunov <gorcunov at openvz.org>
Signed-off-by: Andrew Vagin <avagin at virtuozzo.com>
---
 criu/cr-dump.c            | 15 ++++++---------
 criu/cr-exec.c            |  2 +-
 criu/include/proc_parse.h |  4 +++-
 criu/include/vma.h        |  5 ++++-
 criu/proc_parse.c         | 26 +++++++++++++++++++++++++-
 5 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/criu/cr-dump.c b/criu/cr-dump.c
index 5ac9fd0..b7e30ba 100644
--- a/criu/cr-dump.c
+++ b/criu/cr-dump.c
@@ -114,7 +114,8 @@ void free_mappings(struct vm_area_list *vma_area_list)
 	vma_area_list->nr = 0;
 }
 
-int collect_mappings(pid_t pid, struct vm_area_list *vma_area_list)
+int collect_mappings(pid_t pid, struct vm_area_list *vma_area_list,
+						dump_filemap_t dump_file)
 {
 	int ret = -1;
 
@@ -122,7 +123,7 @@ int collect_mappings(pid_t pid, struct vm_area_list *vma_area_list)
 	pr_info("Collecting mappings (pid: %d)\n", pid);
 	pr_info("----------------------------------------\n");
 
-	ret = parse_smaps(pid, vma_area_list);
+	ret = parse_smaps(pid, vma_area_list, dump_file);
 	if (ret < 0)
 		goto err;
 
@@ -364,8 +365,7 @@ static int dump_pid_misc(pid_t pid, TaskCoreEntry *tc)
 	return 0;
 }
 
-static int dump_filemap(pid_t pid, struct vma_area *vma_area,
-		const struct cr_imgset *imgset)
+static int dump_filemap(struct vma_area *vma_area)
 {
 	struct fd_parms p = FD_PARMS_INIT;
 	VmaEntry *vma = vma_area->e;
@@ -469,9 +469,6 @@ static int dump_task_mm(pid_t pid, const struct proc_pid_stat *stat,
 			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);
 		else if (vma_entry_is(vma, VMA_AREA_SOCKET))
 			ret = dump_socket_map(vma_area);
 		else
@@ -1125,7 +1122,7 @@ static int pre_dump_one_task(struct pstree_item *item, struct list_head *ctls)
 	if (item->pid.state == TASK_DEAD)
 		return 0;
 
-	ret = collect_mappings(pid, &vmas);
+	ret = collect_mappings(pid, &vmas, NULL);
 	if (ret) {
 		pr_err("Collect mappings (pid: %d) failed with %d\n", pid, ret);
 		goto err;
@@ -1205,7 +1202,7 @@ static int dump_one_task(struct pstree_item *item)
 	if (ret < 0)
 		goto err;
 
-	ret = collect_mappings(pid, &vmas);
+	ret = collect_mappings(pid, &vmas, dump_filemap);
 	if (ret) {
 		pr_err("Collect mappings (pid: %d) failed with %d\n", pid, ret);
 		goto err;
diff --git a/criu/cr-exec.c b/criu/cr-exec.c
index e595ec1..a4c07e2 100644
--- a/criu/cr-exec.c
+++ b/criu/cr-exec.c
@@ -147,7 +147,7 @@ int cr_exec(int pid, char **opt)
 	 */
 	free(creds);
 
-	ret = collect_mappings(pid, &vmas);
+	ret = collect_mappings(pid, &vmas, NULL);
 	if (ret) {
 		pr_err("Can't collect vmas for %d\n", pid);
 		goto out_unseize;
diff --git a/criu/include/proc_parse.h b/criu/include/proc_parse.h
index 5de5c86..5ef6989 100644
--- a/criu/include/proc_parse.h
+++ b/criu/include/proc_parse.h
@@ -128,7 +128,9 @@ extern int parse_pid_stat(pid_t pid, struct proc_pid_stat *s);
 extern unsigned int parse_pid_loginuid(pid_t pid, int *err, bool ignore_noent);
 extern int parse_pid_oom_score_adj(pid_t pid, int *err);
 extern int prepare_loginuid(unsigned int value, unsigned int loglevel);
-extern int parse_smaps(pid_t pid, struct vm_area_list *vma_area_list);
+struct vma_area;
+typedef int (*dump_filemap_t)(struct vma_area *vma_area);
+extern int parse_smaps(pid_t pid, struct vm_area_list *vma_area_list, dump_filemap_t cb);
 extern int parse_self_maps_lite(struct vm_area_list *vms);
 extern int parse_pid_status(pid_t pid, struct proc_status_creds *);
 
diff --git a/criu/include/vma.h b/criu/include/vma.h
index d69f5f0..15db4ea 100644
--- a/criu/include/vma.h
+++ b/criu/include/vma.h
@@ -71,8 +71,11 @@ struct vma_area {
 	};
 };
 
+typedef int (*dump_filemap_t)(struct vma_area *vma_area);
+
 extern struct vma_area *alloc_vma_area(void);
-extern int collect_mappings(pid_t pid, struct vm_area_list *vma_area_list);
+extern int collect_mappings(pid_t pid,
+		struct vm_area_list *vma_area_list, dump_filemap_t cb);
 extern void free_mappings(struct vm_area_list *vma_area_list);
 
 #define vma_area_is(vma_area, s)	vma_entry_is((vma_area)->e, s)
diff --git a/criu/proc_parse.c b/criu/proc_parse.c
index 4522ce6..10badfe 100644
--- a/criu/proc_parse.c
+++ b/criu/proc_parse.c
@@ -592,7 +592,22 @@ static int vma_list_add(struct vma_area *vma_area,
 	return 0;
 }
 
-int parse_smaps(pid_t pid, struct vm_area_list *vma_area_list)
+static void close_prev_vma(struct vma_area *vma, bool borrowed)
+{
+	if (!vma)
+		return;
+
+	if (!vma_entry_is(vma->e, VMA_FILE_PRIVATE) &&
+			!vma_entry_is(vma->e, VMA_FILE_SHARED))
+		return;
+
+	if (!borrowed)
+		close_safe(&vma->vm_file_fd);
+	vma->vm_file_fd = -1;
+}
+
+int parse_smaps(pid_t pid, struct vm_area_list *vma_area_list,
+					dump_filemap_t dump_filemap)
 {
 	struct vma_area *vma_area = NULL;
 	unsigned long start, end, pgoff, prev_end = 0;
@@ -694,7 +709,16 @@ int parse_smaps(pid_t pid, struct vm_area_list *vma_area_list)
 		if (handle_vma(pid, vma_area, str + path_off, map_files_dir,
 					&vfi, &prev_vfi, vma_area_list))
 			goto err;
+
+		if (vma_entry_is(vma_area->e, VMA_FILE_PRIVATE) ||
+				vma_entry_is(vma_area->e, VMA_FILE_SHARED)) {
+			if (dump_filemap && dump_filemap(vma_area))
+				goto err;
+		}
+
+		close_prev_vma(prev_vfi.vma, vma_area->file_borrowed);
 	}
+	close_prev_vma(prev_vfi.vma, false);
 
 	vma_area = NULL;
 	ret = 0;
-- 
2.5.5