[CRIU] [PATCH 7/8] files: add ability to set callbacks for files (v3)
Andrey Vagin
avagin at openvz.org
Thu Dec 12 09:12:58 PST 2013
Here is nothing interecting. If a file can't be dumped by criu,
plugins are called. If one of plugins knows how to dump the file,
the file entry is marked as need_callback. On restore if we see
this mark, we execute plugins for restoring the file.
v2: Callbacks are called for all files, which are not supported by CRIU.
v3: Call plugins for a file instead of file descriptor. A few file
descriptors can be associated with one file.
Signed-off-by: Andrey Vagin <avagin at openvz.org>
---
files-reg.c | 17 ++++++++++++++++-
files.c | 38 +++++++++++++++++++++++++++++++-------
include/criu-plugin.h | 3 +++
include/files-reg.h | 7 ++++++-
include/plugin.h | 3 +++
plugin.c | 20 ++++++++++++++++++++
protobuf/regfile.proto | 1 +
7 files changed, 80 insertions(+), 9 deletions(-)
diff --git a/files-reg.c b/files-reg.c
index fb5d7ca..2e59ea7 100644
--- a/files-reg.c
+++ b/files-reg.c
@@ -20,6 +20,7 @@
#include "protobuf/remap-file-path.pb-c.h"
#include "files-reg.h"
+#include "plugin.h"
/*
* Ghost files are those not visible from the FS. Dumping them is
@@ -477,13 +478,18 @@ static int check_path_remap(char *rpath, int plen, const struct stat *ost, int l
return 0;
}
-int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p)
+int __dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p, bool cb)
{
struct fd_link _link, *link;
int rfd;
RegFileEntry rfe = REG_FILE_ENTRY__INIT;
+ if (cb) {
+ rfe.has_need_callback = true;
+ rfe.need_callback = true;
+ }
+
if (!p->link) {
if (fill_fdlink(lfd, p, &_link))
return -1;
@@ -583,6 +589,15 @@ static int do_open_reg(struct reg_file_info *rfi, void *arg)
return fd;
}
+ if (rfi->rfe->need_callback) {
+ if (cr_plugin_restore_file(fd, rfi->rfe->id)) {
+ pr_err("Unable to restore %#x\n", rfi->rfe->id);
+ close(fd);
+ return -1;
+ }
+ return fd;
+ }
+
if ((rfi->rfe->pos != -1ULL) &&
lseek(fd, rfi->rfe->pos, SEEK_SET) < 0) {
pr_perror("Can't restore file pos");
diff --git a/files.c b/files.c
index 6eb7282..7f7003a 100644
--- a/files.c
+++ b/files.c
@@ -39,6 +39,8 @@
#include "protobuf.h"
#include "protobuf/fs.pb-c.h"
+#include "plugin.h"
+
#define FDESC_HASH_SIZE 64
static struct hlist_head file_desc_hash[FDESC_HASH_SIZE];
@@ -239,9 +241,32 @@ static int fill_fd_params(struct parasite_ctl *ctl, int fd, int lfd,
return 0;
}
-static int dump_unsupp_fd(const struct fd_parms *p, char *more, char *info)
+int dump_one_unsupp_file(int lfd, u32 id, const struct fd_parms *p)
+{
+ int ret;
+
+ ret = cr_plugin_dump_file(lfd, id);
+ if (ret < 0)
+ return ret;
+
+ return __dump_one_reg_file(lfd, id, p, true);
+}
+
+const struct fdtype_ops unsupp_dump_ops = {
+ .type = FD_TYPES__REG,
+ .dump = dump_one_unsupp_file,
+};
+
+static int dump_unsupp_fd(struct fd_parms *p, int lfd,
+ const int fdinfo, char *more, char *info)
{
- pr_err("Can't dump file %d of that type [%o] (%s %s)\n",
+ int ret;
+
+ ret = do_dump_gen_file(p, lfd, &unsupp_dump_ops, fdinfo);
+ if (ret == 0)
+ return 0;
+ if (ret == CRIU_CB_SKIP)
+ pr_err("Can't dump file %d of that type [%o] (%s %s)\n",
p->fd, p->stat.st_mode, more, info);
return -1;
}
@@ -277,9 +302,8 @@ static int dump_chrdev(struct fd_parms *p, int lfd, const int fdinfo)
/* fallthrough */
default: {
char more[32];
-
sprintf(more, "%d:%d", maj, minor(p->stat.st_dev));
- return dump_unsupp_fd(p, "chr", more);
+ return dump_unsupp_fd(p, lfd, fdinfo, "chr", more);
}
}
@@ -330,7 +354,7 @@ static int dump_one_file(struct parasite_ctl *ctl, int fd, int lfd, struct fd_op
if (read_fd_link(fd, more, sizeof(more)))
more[0] = '\0';
- return dump_unsupp_fd(&p, "anon", more);
+ return dump_unsupp_fd(&p, lfd, fdinfo, "anon", more);
}
return do_dump_gen_file(&p, lfd, ops, fdinfo);
@@ -349,7 +373,7 @@ static int dump_one_file(struct parasite_ctl *ctl, int fd, int lfd, struct fd_op
if (check_ns_proc(&link))
return do_dump_gen_file(&p, lfd, &nsfile_dump_ops, fdinfo);
- return dump_unsupp_fd(&p, "reg", link.name + 1);
+ return dump_unsupp_fd(&p, lfd, fdinfo, "reg", link.name + 1);
}
if (S_ISFIFO(p.stat.st_mode)) {
@@ -361,7 +385,7 @@ static int dump_one_file(struct parasite_ctl *ctl, int fd, int lfd, struct fd_op
return do_dump_gen_file(&p, lfd, ops, fdinfo);
}
- return dump_unsupp_fd(&p, "unknown", NULL);
+ return dump_unsupp_fd(&p, lfd, fdinfo, "unknown", NULL);
}
int dump_task_files_seized(struct parasite_ctl *ctl, struct pstree_item *item,
diff --git a/include/criu-plugin.h b/include/criu-plugin.h
index d4ea30c..eb71362 100644
--- a/include/criu-plugin.h
+++ b/include/criu-plugin.h
@@ -21,6 +21,7 @@
#define __CRIU_PLUGIN_H__
#include <limits.h>
+#include <stdbool.h>
typedef int (cr_plugin_init_t)(void);
typedef void (cr_plugin_fini_t)(void);
@@ -31,6 +32,8 @@ typedef void (cr_plugin_fini_t)(void);
typedef int (cr_plugin_dump_unix_sk_t)(int fd, int id);
typedef int (cr_plugin_restore_unix_sk_t)(int id);
+typedef int (cr_plugin_dump_file_t)(int fd, int id);
+typedef int (cr_plugin_restore_file_t)(int fd, int id);
extern void print_on_level(unsigned int loglevel, const char *format, ...)
__attribute__ ((__format__ (__printf__, 2, 3)));
diff --git a/include/files-reg.h b/include/files-reg.h
index d3bd4f0..087a2d8 100644
--- a/include/files-reg.h
+++ b/include/files-reg.h
@@ -30,7 +30,12 @@ extern void clear_ghost_files(void);
extern int prepare_shared_reg_files(void);
extern const struct fdtype_ops regfile_dump_ops;
-extern int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p);
+int __dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p, bool cb);
+static inline int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p)
+{
+ return __dump_one_reg_file(lfd, id, p, false);
+}
+
extern struct file_remap *lookup_ghost_remap(u32 dev, u32 ino);
extern void remap_put(struct file_remap *remap);
diff --git a/include/plugin.h b/include/plugin.h
index a70dde3..a8909be 100644
--- a/include/plugin.h
+++ b/include/plugin.h
@@ -11,4 +11,7 @@ int cr_plugin_init(void);
int cr_plugin_dump_unix_sk(int fd, int id);
int cr_plugin_restore_unix_sk(int id);
+int cr_plugin_dump_file(int fd, int id);
+int cr_plugin_restore_file(int fd, int id);
+
#endif
diff --git a/plugin.c b/plugin.c
index ce5fb10..bd41639 100644
--- a/plugin.c
+++ b/plugin.c
@@ -17,6 +17,8 @@ struct cr_plugin_entry {
cr_plugin_dump_unix_sk_t *cr_plugin_dump_unix_sk;
cr_plugin_restore_unix_sk_t *cr_plugin_restore_unix_sk;
+ cr_plugin_dump_file_t *cr_plugin_dump_file;
+ cr_plugin_restore_file_t *cr_plugin_restore_file;
};
struct cr_plugin_entry *next;
@@ -27,6 +29,8 @@ struct cr_plugins {
struct cr_plugin_entry *cr_plugin_dump_unix_sk;
struct cr_plugin_entry *cr_plugin_restore_unix_sk;
+ struct cr_plugin_entry *cr_plugin_dump_file;
+ struct cr_plugin_entry *cr_plugin_restore_file;
};
struct cr_plugins cr_plugins;
@@ -73,6 +77,16 @@ int cr_plugin_restore_unix_sk(int id)
return run_plugin_funcs(cr_plugin_restore_unix_sk, id);
}
+int cr_plugin_dump_file(int fd, int id)
+{
+ return run_plugin_funcs(cr_plugin_dump_file, fd, id);
+}
+
+int cr_plugin_restore_file(int fd, int id)
+{
+ return run_plugin_funcs(cr_plugin_restore_file, fd, id);
+}
+
static int cr_lib_load(char *path)
{
struct cr_plugin_entry *ce;
@@ -89,6 +103,9 @@ static int cr_lib_load(char *path)
add_plugin_func(cr_plugin_dump_unix_sk);
add_plugin_func(cr_plugin_restore_unix_sk);
+ add_plugin_func(cr_plugin_dump_file);
+ add_plugin_func(cr_plugin_restore_file);
+
ce = NULL;
f_fini = dlsym(h, "cr_plugin_fini");
if (f_fini) {
@@ -127,6 +144,9 @@ void cr_plugin_fini(void)
cr_plugin_free(cr_plugin_dump_unix_sk);
cr_plugin_free(cr_plugin_restore_unix_sk);
+ cr_plugin_free(cr_plugin_dump_file);
+ cr_plugin_free(cr_plugin_restore_file);
+
while (cr_plugins.cr_fini) {
ce = cr_plugins.cr_fini;
cr_plugins.cr_fini = cr_plugins.cr_fini->next;
diff --git a/protobuf/regfile.proto b/protobuf/regfile.proto
index d975ab0..925d39a 100644
--- a/protobuf/regfile.proto
+++ b/protobuf/regfile.proto
@@ -6,4 +6,5 @@ message reg_file_entry {
required uint64 pos = 3;
required fown_entry fown = 5;
required string name = 6;
+ optional bool need_callback = 7;
}
--
1.8.3.1
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