[CRIU] [PATCH 01/28] dump: global image names introduced

[Kinsbursky Stanislav]

From: Stanislav Kinsbursky <skinsbursky at openvz.org>

Signed-off-by: Stanislav Kinsbursky <skinsbursky at openvz.org>
---
 crtools.c         |    6 ++++++
 include/crtools.h |    4 ++++
 util.c            |   11 ++++++++++-
 3 files changed, 20 insertions(+), 1 deletions(-)
-------------- next part --------------
diff --git a/crtools.c b/crtools.c
index b461679..6f067c0 100644
--- a/crtools.c
+++ b/crtools.c
@@ -235,6 +235,12 @@ struct cr_fdset *cr_show_fdset_open(int pid, unsigned long use_mask)
 	return cr_fdset_open(pid, use_mask, O_RDONLY, NULL);
 }
 
+struct cr_fdset *cr_glob_fdset_open(unsigned long use_mask,
+				    struct cr_fdset *cr_fdset)
+{
+	return cr_fdset_open(0, use_mask, O_WRONLY | O_APPEND | O_CREAT, cr_fdset);
+}
+
 static int parse_ns_string(const char *ptr, unsigned int *flags)
 {
 	const char *end = ptr + strlen(ptr);
diff --git a/include/crtools.h b/include/crtools.h
index 90eec0d..3faba43 100644
--- a/include/crtools.h
+++ b/include/crtools.h
@@ -105,6 +105,9 @@ int open_image(int type, unsigned long flags, ...);
 #define open_image_ro(type, ...) open_image(type, O_RDONLY, __VA_ARGS__);
 extern int open_image_ro_nocheck(const char *fmt, int pid);
 
+#define open_glob_image_ro(type) open_image(type, O_RDONLY);
+#define open_glob_image_ro_nocheck(fmt) open_image_ro_nocheck(fmt, 0);
+
 #define LAST_PID_PATH		"/proc/sys/kernel/ns_last_pid"
 #define LAST_PID_PERM		0666
 
@@ -143,6 +146,7 @@ int cr_check(void);
 
 struct cr_fdset *cr_dump_fdset_open(int pid, unsigned long use_mask, struct cr_fdset *);
 struct cr_fdset *cr_show_fdset_open(int pid, unsigned long use_mask);
+struct cr_fdset *cr_glob_fdset_open(unsigned long use_mask, struct cr_fdset *);
 void close_cr_fdset(struct cr_fdset **cr_fdset);
 
 void free_mappings(struct list_head *vma_area_list);
diff --git a/util.c b/util.c
index 44d264c..cb0ab65 100644
--- a/util.c
+++ b/util.c
@@ -167,6 +167,7 @@ int open_image(int type, unsigned long flags, ...)
 	char path[PATH_MAX];
 	va_list args;
 	int ret;
+	int write_magic = 1;
 
 	va_start(args, flags);
 	vsnprintf(path, PATH_MAX, fdset_template[type].fmt, args);
@@ -180,6 +181,14 @@ int open_image(int type, unsigned long flags, ...)
 		}
 	}
 
+	if (flags & O_APPEND) {
+		ret = faccessat(image_dir_fd, path, R_OK, 0);
+		if (!ret)
+			write_magic = 0;
+		else if (errno != ENOENT)
+			return ret;
+	}
+
 	ret = openat(image_dir_fd, path, flags, CR_FD_PERM);
 	if (ret < 0) {
 		pr_perror("Unable to open %s", path);
@@ -195,7 +204,7 @@ int open_image(int type, unsigned long flags, ...)
 			pr_err("Magic doesn't match for %s\n", path);
 			goto err;
 		}
-	} else {
+	} else if (write_magic) {
 		if (write_img(ret, &fdset_template[type].magic))
 			goto err;
 	}