Currently we have no way how to specify dependencies between fstab
entries (or another units) in the /etc/fstab. It means that users are
forced to bypass fstab and write .mount units manually.
The patch introduces new systemd fstab options:
x-systemd.requires=<PATH>
- to specify dependence an another mount (PATH is translated to unit name)
x-systemd.requires=<UNIT>
- to specify dependence on arbitrary UNIT
x-systemd.requires-mounts-for=<PATH ...>
- to specify dependence on another paths, implemented by
RequiresMountsFor=. The option may be specified more than once.
For example two bind mounts where B depends on A:
/mnt/test/A /mnt/test/A none bind,defaults
/mnt/test/A /mnt/test/B none bind,x-systemd.requires=/mnt/test/A
More complex example with overlay FS where one mount point depends on
"low" and "upper" directories:
/dev/sdc1 /mnt/low ext4 defaults
/dev/sdc2 /mnt/high ext4 defaults
overlay /mnt/merged overlay lowerdir=/mnt/low,upperdir=/mnt/high/data,workdir=/mnt/high/work,x-systemd.requires-mounts-for=/mnt/low,x-systemd.requires-mounts-for=mnt/high
https://bugzilla.redhat.com/show_bug.cgi?id=812826
https://bugzilla.redhat.com/show_bug.cgi?id=
1164334
return !!n;
}
+int fstab_extract_values(const char *opts, const char *name, char ***values) {
+ _cleanup_strv_free_ char **optsv = NULL, **res = NULL;
+ char **s;
+
+ assert(opts);
+ assert(name);
+ assert(values);
+
+ optsv = strv_split(opts, ",");
+ if (!optsv)
+ return -ENOMEM;
+
+ STRV_FOREACH(s, optsv) {
+ char *arg;
+ int r;
+
+ arg = startswith(*s, name);
+ if (!arg || *arg != '=')
+ continue;
+ r = strv_extend(&res, arg + 1);
+ if (r < 0)
+ return r;
+ }
+
+ *values = res;
+ res = NULL;
+
+ return !!*values;
+}
+
int fstab_find_pri(const char *options, int *ret) {
_cleanup_free_ char *opt = NULL;
int r;
int fstab_filter_options(const char *opts, const char *names,
const char **namefound, char **value, char **filtered);
+int fstab_extract_values(const char *opts, const char *name, char ***values);
+
static inline bool fstab_test_option(const char *opts, const char *names) {
return !!fstab_filter_options(opts, names, NULL, NULL, NULL);
}