libmount: correctly interpret '*' from /etc/filesystems

 - single line with '*' in /etc/filesystems means that libmount has to
   read /proc/filesystems, otherwise /proc/filesystems has to be ignored

 - mount(2) ENODEV is no reason to break the do_mount_by_pattern()
   loop when trying to mount by /{etc,proc}/filesystems

Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libmount/src/context_mount.c b/libmount/src/context_mount.c
index 1e21db7c670303be2e1cb7fe88d956a7adcf847a..196e3a249c554765682812773aa06c6ab79eac6f 100644 (file)
--- a/libmount/src/context_mount.c
+++ b/libmount/src/context_mount.c
@@ -590,7 +590,8 @@ static int do_mount_by_pattern(struct libmnt_context *cxt, const char *pattern)
                rc = do_mount(cxt, *fp);
                if (mnt_context_get_status(cxt))
                        break;
-               if (mnt_context_get_syscall_errno(cxt) != EINVAL)
+               if (mnt_context_get_syscall_errno(cxt) != EINVAL &&
+                   mnt_context_get_syscall_errno(cxt) != ENODEV)
                        break;
        }
        mnt_free_filesystems(filesystems);

diff --git a/libmount/src/utils.c b/libmount/src/utils.c
index 624633dd85cbfb46410ea7faeaaa8ce805497dbf..28eca7c82fee6dac115e635eb81785eeff8d72da 100644 (file)
--- a/libmount/src/utils.c
+++ b/libmount/src/utils.c
@@ -453,7 +453,9 @@ static int get_filesystems(const char *filename, char ***filesystems, const char
 
        f = fopen(filename, "r");
        if (!f)
-               return 0;
+               return 1;
+
+       DBG(UTILS, mnt_debug("reading filesystems list from: %s", filename));
 
        while (fgets(line, sizeof(line), f)) {
                char name[sizeof(line)];
@@ -462,6 +464,10 @@ static int get_filesystems(const char *filename, char ***filesystems, const char
                        continue;
                if (sscanf(line, " %128[^\n ]\n", name) != 1)
                        continue;
+               if (strcmp(name, "*") == 0) {
+                       rc = 1;
+                       break;          /* end of the /etc/filesystems */
+               }
                if (pattern && !mnt_match_fstype(name, pattern))
                        continue;
                rc = add_filesystem(filesystems, name);
@@ -474,8 +480,15 @@ static int get_filesystems(const char *filename, char ***filesystems, const char
 }
 
 /*
- * Returns zero also if not found any matching filesystem. Always check
- * @filesystems pointer!
+ * Always check @filesystems pointer!
+ *
+ * man mount:
+ *
+ * ...mount will try to read the file /etc/filesystems, or, if that does not
+ * exist, /proc/filesystems. All of the filesystem  types  listed  there  will
+ * be tried,  except  for  those  that  are  labeled  "nodev"  (e.g.,  devpts,
+ * proc  and  nfs).  If /etc/filesystems ends in a line with a single * only,
+ * mount will read /proc/filesystems after‐ wards.
  */
 int mnt_get_filesystems(char ***filesystems, const char *pattern)
 {
@@ -483,12 +496,18 @@ int mnt_get_filesystems(char ***filesystems, const char *pattern)
 
        if (!filesystems)
                return -EINVAL;
+
        *filesystems = NULL;
 
        rc = get_filesystems(_PATH_FILESYSTEMS, filesystems, pattern);
-       if (rc)
+       if (rc != 1)
                return rc;
-       return get_filesystems(_PATH_PROC_FILESYSTEMS, filesystems, pattern);
+
+       rc = get_filesystems(_PATH_PROC_FILESYSTEMS, filesystems, pattern);
+       if (rc == 1 && *filesystems)
+               rc = 0;                 /* not found /proc/filesystems */
+
+       return rc;
 }
 
 static size_t get_pw_record_size(void)