For example, it can be used to disable udev's parsing of metadata and
the creation of persistent symlinks for that device [1], to avoid
unnecessary network access that can take some time.
```sh
cat << EOF > /etc/udev/rules.d/59-skip-nbd-erofs-persistent-storage.rules
IMPORT{db}="UDEV_DISABLE_PERSISTENT_STORAGE_RULES_FLAG"
IMPORT{program}="/usr/local/bin/dump.erofs --blkid-udev %N"
ACTION=="add|change", SUBSYSTEM=="block", KERNEL=="nbd*",
ENV{ID_FS_TYPE}=="erofs", ENV{UDEV_DISABLE_PERSISTENT_STORAGE_RULES_FLAG}="1"
EOF
```
[1] https://github.com/systemd/systemd/pull/3714
Cc: Chengyu Zhu <[email protected]>
Signed-off-by: Gao Xiang <[email protected]>
---
dump/main.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/dump/main.c b/dump/main.c
index f685799..4ad3f7b 100644
--- a/dump/main.c
+++ b/dump/main.c
@@ -26,6 +26,7 @@ struct erofsdump_cfg {
bool show_statistics;
bool show_subdirectories;
bool show_file_content;
+ bool show_blkid_udev;
erofs_nid_t nid;
const char *inode_path;
};
@@ -81,6 +82,7 @@ static struct option long_options[] = {
{"ls", no_argument, NULL, 5},
{"offset", required_argument, NULL, 6},
{"cat", no_argument, NULL, 7},
+ {"blkid-udev", no_argument, NULL, 512},
{0, 0, 0, 0},
};
@@ -125,6 +127,7 @@ static void usage(int argc, char **argv)
" -S show statistic information of the image\n"
" -e show extent info (INODE required)\n"
" -s show information about superblock\n"
+ " --blkid-udev print block device attributes for easy import
into the udev environment\n"
" --device=X specify an extra device to be used together\n"
" --ls show directory contents (INODE required)\n"
" --cat show file contents (INODE required)\n"
@@ -198,6 +201,9 @@ static int erofsdump_parse_options_cfg(int argc, char
**argv)
case 7:
dumpcfg.show_file_content = true;
break;
+ case 512:
+ dumpcfg.show_blkid_udev = true;
+ break;
default:
return -EINVAL;
}
@@ -765,6 +771,9 @@ int main(int argc, char **argv)
goto exit;
}
+ if (dumpcfg.show_blkid_udev)
+ cfg.c_dbg_lvl = -1;
+
err = erofs_dev_open(&g_sbi, cfg.c_img_path, O_RDONLY | O_TRUNC);
if (err) {
erofs_err("failed to open image file");
@@ -777,6 +786,15 @@ int main(int argc, char **argv)
goto exit_dev_close;
}
+ if (dumpcfg.show_blkid_udev) {
+ char uuid_str[37];
+
+ erofs_uuid_unparse_lower(g_sbi.uuid, uuid_str);
+
printf("ID_FS_UUID=%s\nID_FS_UUID_ENC=%s\nID_FS_TYPE=erofs\nID_FS_USAGE=filesystem\n",
+ uuid_str, uuid_str);
+ goto exit_put_super;
+ }
+
if (dumpcfg.show_file_content) {
if (dumpcfg.show_superblock || dumpcfg.show_statistics ||
dumpcfg.show_subdirectories) {
fprintf(stderr, "The '--cat' flag is incompatible with
'-S', '-e', '-s' and '--ls'.\n");
--
2.43.5
