devmapper: add devmapper_rm_layer、devmapper_create_ro、devmapper_create_rw and...

devmapper: add devmapper_rm_layer、devmapper_create_ro、devmapper_create_rw and devmapper_umount_layer func
Signed-off-by: Ngaohuatao <gaohuatao@huawei.com>

src/image/oci/storage/layer_store/graphdriver/devmapper/deviceset.c

@@ -170,7 +170,7 @@ static int devmapper_parse_options(struct device_set *devset, const char **optio
     return 0;
 }
 
-void free_device_set(struct device_set *ptr)
+static void free_device_set(struct device_set *ptr)
 {
     if (ptr == NULL) {
         return;
@@ -1996,7 +1996,7 @@ free_out:
     UTIL_FREE_AND_SET_NULL(dev_fname);
 }
 
-int delete_device(struct device_set *devset, const char *hash, bool sync_delete)
+static int do_delete_device(struct device_set *devset, const char *hash, bool sync_delete)
 {
     int ret;
     bool deferred_remove;
@@ -2062,7 +2062,7 @@ static int setup_base_image(struct device_set *devset)
         }
 
         DEBUG("devmapper: Removing uninitialized base image");
-        ret = delete_device(devset, "", true);
+        ret = do_delete_device(devset, "", true);
         if (ret != 0) {
             goto out;
         }
@@ -2577,4 +2577,79 @@ free_out:
     }
     free_image_devmapper_device_info(info);
     return ret;
+}
+
+bool has_device(const char *hash)
+{
+    bool res = false;
+    image_devmapper_device_info *info = NULL;
+    struct device_set *devset = NULL;
+
+    if (hash == NULL) {
+        ERROR("devmapper: failed to judge device metadata exists");
+        return false;
+    }
+
+    if (devmapper_conf_wrlock()) {
+        ERROR("lock devmapper conf failed");
+        return false;
+    }
+
+    devset = devmapper_driver_devices_get();
+    if (devset == NULL) {
+        goto free_out;
+    }
+
+    info = lookup_device(devset, hash);
+    if (info == NULL) {
+        ERROR("devmapper: lookup device %s failed", hash);
+        goto free_out;
+    }
+
+    res = true;
+free_out:
+    if (devmapper_conf_unlock()) {
+        ERROR("unlock devmapper conf failed");
+    }
+    free_image_devmapper_device_info(info);
+    return res;
+}
+
+int delete_device(const char *hash, bool sync_delete)
+{
+    int ret = 0;
+    image_devmapper_device_info *info = NULL;
+    struct device_set *devset = NULL;
+
+    if (hash == NULL) {
+        return -1;
+    }
+
+    if (devmapper_conf_wrlock()) {
+        ERROR("lock devmapper conf failed");
+        return -1;
+    }
+
+    devset = devmapper_driver_devices_get();
+    if (devset == NULL) {
+        ret = -1;
+        goto free_out;
+    }
+
+    info = lookup_device(devset, hash);
+    if (info == NULL) {
+        ret = -1;
+        ERROR("devmapper: lookup device %s failed", hash);
+        goto free_out;
+    }
+
+    ret = do_delete_device(devset, hash, sync_delete);
+
+free_out:
+    if (devmapper_conf_unlock()) {
+        ret = -1;
+        ERROR("unlock devmapper conf failed");
+    }
+    free_image_devmapper_device_info(info);
+    return ret;
 }
\ No newline at end of file

src/image/oci/storage/layer_store/graphdriver/devmapper/deviceset.h

@@ -80,6 +80,9 @@ struct device_set *devmapper_driver_devices_get();
 int add_device(const char *hash, const char *base_hash, const json_map_string_string *storage_opts);
 int mount_device(const char *hash, const char *path, const struct driver_mount_opts *mount_opts);
 int unmount_device(const char *hash, const char *mount_path);
+bool has_device(const char *hash);
+
+int delete_device(const char *hash, bool sync_delete);
 
 #ifdef __cplusplus
 }

src/image/oci/storage/layer_store/graphdriver/devmapper/driver_devmapper.c

@@ -38,7 +38,7 @@ int devmapper_init(struct graphdriver *driver, const char *drvier_home, const ch
     return device_init(driver, drvier_home, options, len);
 }
 
-int do_create(const char *id, const char *parent, const struct driver_create_opts *create_opts)
+static int do_create(const char *id, const char *parent, const struct driver_create_opts *create_opts)
 {
     return add_device(id, parent, create_opts->storage_opt);
 }
@@ -54,15 +54,58 @@ int devmapper_create_rw(const char *id, const char *parent, const struct graphdr
     return do_create(id, parent, create_opts);
 }
 
+// Create adds a device with a given id and the parent.
 int devmapper_create_ro(const char *id, const char *parent, const struct graphdriver *driver,
                         const struct driver_create_opts *create_opts)
 {
-    return 0;
+    if (id == NULL || parent == NULL || driver == NULL || create_opts == NULL) {
+        return -1;
+    }
+
+    return do_create(id, parent, create_opts);
 }
 
+// Remove removes a device with a given id, unmounts the filesystem.
 int devmapper_rm_layer(const char *id, const struct graphdriver *driver)
 {
-    return 0;
+    char *mnt_parent_dir = NULL;
+    char *mnt_point_dir = NULL;
+    int ret = 0;
+
+    if (id == NULL || driver == NULL) {
+        return -1;
+    }
+
+    if (!has_device(id)) {
+        return 0;
+    }
+
+    ret = delete_device(id, false);
+    if (ret != 0) {
+        ERROR("failed to remove device %s", id);
+        return ret;
+    }
+
+    mnt_parent_dir = util_path_join(driver->home, "mnt");
+    if (mnt_parent_dir == NULL) {
+        ret = -1;
+        ERROR("Failed to join devmapper mnt dir %s", id);
+        goto out;
+    }
+
+    mnt_point_dir = util_path_join(mnt_parent_dir, id);
+    if (mnt_point_dir == NULL) {
+        ret = -1;
+        ERROR("Failed to join devampper mount point dir %s", id);
+        goto out;
+    }
+
+    ret = util_path_remove(mnt_point_dir);
+
+out:
+    free(mnt_parent_dir);
+    free(mnt_point_dir);
+    return ret;
 }
 
 static int write_file(const char *fpath, const char *buf)
@@ -162,12 +205,42 @@ out:
 
 int devmapper_umount_layer(const char *id, const struct graphdriver *driver)
 {
-    return 0;
+    int ret = 0;
+    char *mp = NULL;
+    char *mnt_dir = NULL;
+
+    if (id == NULL || driver == NULL) {
+        return -1;
+    }
+
+    mnt_dir = util_path_join(driver->home, "mnt");
+    if (mnt_dir == NULL) {
+        ERROR("Failed to join layer dir mnt");
+        ret = -1;
+        goto out;
+    }
+
+    mp = util_path_join(mnt_dir, id);
+    if (mp == NULL) {
+        ERROR("Failed to join layer dir:%s", id);
+        ret = -1;
+        goto out;
+    }
+
+    ret = unmount_device(id, mp);
+    if (ret != 0) {
+        DEBUG("devmapper: unmount %s failed", mp);
+    }
+
+out:
+    free(mnt_dir);
+    free(mp);
+    return ret;
 }
 
 bool devmapper_layer_exists(const char *id, const struct graphdriver *driver)
 {
-    return true;
+    return has_device(id);
 }
 
 int devmapper_apply_diff(const char *id, const struct graphdriver *driver, const struct io_read_wrapper *content,