libmount: add mnt_get_writable_mtab_path()

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/shlibs/mount/src/mount.h.in b/shlibs/mount/src/mount.h.in
index fcb4b4e5a79976b35f3bff05d06c58eb820c17f0..46934a9881bd0061838cb372ecca267befc33792 100644 (file)
--- a/shlibs/mount/src/mount.h.in
+++ b/shlibs/mount/src/mount.h.in
@@ -114,6 +114,7 @@ extern int mnt_fstype_is_netfs(const char *type);
 extern int mnt_fstype_is_pseudofs(const char *type);
 extern int mnt_match_fstype(const char *type, const char *pattern);
 extern int mnt_match_options(const char *optstr, const char *pattern);
+extern const char *mnt_get_writable_mtab_path(void);
 
 /* cache.c */
 extern mnt_cache *mnt_new_cache(void);
@@ -209,10 +210,12 @@ extern char *mnt_optls_create_userspace_optstr(mnt_optls *ls);
 extern int mnt_optls_print_debug(mnt_optls *ls, FILE *file);
 
 /* lock.c */
-extern mnt_lock *mnt_new_lock(const char *lockfile, pid_t id);
+extern mnt_lock *mnt_new_lock(const char *lockname, pid_t id);
 extern void mnt_free_lock(mnt_lock *ml);
+
 extern const char *mnt_lock_get_lockfile(mnt_lock *ml);
 extern const char *mnt_lock_get_linkfile(mnt_lock *ml);
+
 extern void mnt_unlock_file(mnt_lock *ml);
 extern int mnt_lock_file(mnt_lock *ml);
 

diff --git a/shlibs/mount/src/mount.sym b/shlibs/mount/src/mount.sym
index 14d9fbf4ef71d5ff0f74462efa925980d276a081..5596d87cca6eb08f749cccae017573cf8606ac20 100644 (file)
--- a/shlibs/mount/src/mount.sym
+++ b/shlibs/mount/src/mount.sym
@@ -51,6 +51,7 @@ global:
        mnt_fstype_is_pseudofs;
        mnt_get_builtin_optmap;
        mnt_get_library_version;
+       mnt_get_writable_mtab_path;
        mnt_init_debug;
        mnt_iter_get_direction;
        mnt_lock_file;

diff --git a/shlibs/mount/src/utils.c b/shlibs/mount/src/utils.c
index 9bdd62adee9296ecce58fdf5211558ea2dda7ef6..67b00c31648baa80d92be2b8543e1d747eedb8c7 100644 (file)
--- a/shlibs/mount/src/utils.c
+++ b/shlibs/mount/src/utils.c
@@ -262,6 +262,43 @@ int mnt_has_regular_mtab(void)
        return 0;
 }
 
+/**
+ * mnt_get_writable_mtab_path:
+ *
+ * Returns: pointer to the static string with path to the file with userspace
+ *          mount options (classic /etc/mtab or /var/run/mount/mountinfo)
+ */
+const char *mnt_get_writable_mtab_path(void)
+{
+       struct stat mst, ist;
+       int mtab, info;
+
+       mtab = !lstat(_PATH_MOUNTED, &mst);
+       info = !stat(MNT_PATH_RUNDIR, &ist);
+
+       /* A) mtab is symlink, /var/run/mount is available */
+       if (mtab && S_ISLNK(mst.st_mode) && info) {
+               int fd = open(MNT_PATH_MOUNTINFO, O_RDWR | O_CREAT, 0644);
+               if (fd >= 0) {
+                       close(fd);
+                       return MNT_PATH_MOUNTINFO;
+               }
+               return NULL;    /* probably EACCES */
+       }
+
+       /* B) classis system with /etc/mtab */
+       if (mtab && S_ISREG(mst.st_mode)) {
+               int fd = open(_PATH_MOUNTED, O_RDWR, 0644);
+               if (fd >= 0) {
+                       close(fd);
+                       return _PATH_MOUNTED;
+               }
+               return NULL;    /* probably EACCES */
+       }
+
+       return NULL;
+}
+
 #ifdef TEST_PROGRAM
 int test_match_fstype(struct mtest *ts, int argc, char *argv[])
 {