cryptsetup: rework how we log about activation failures

First of all let's always log where the errors happen, and not in an
upper stackframe, in all cases. Previously we'd do this somethis one way
and sometimes another, which resulted in sometimes duplicate logging and
sometimes none.

When we cannot activate something due to bad password the kernel gives
us EPERM. Let's uniformly return this EAGAIN, so tha the next password
is tried. (previously this was done in most cases but not in all)

When we get EPERM let's also explicitly indicate that this probably
means the password is simply wrong.

Fixes: #11498
(cherry picked from commit 6f177c7)

Related: #1776408

src/cryptsetup/cryptsetup.c

@@ -469,10 +469,15 @@ static int attach_tcrypt(
                         log_error("Failed to activate using password file '%s'.", key_file);
                         return -EAGAIN;
                 }
-                return r;
+
+                return log_error_errno(r, "Failed to load tcrypt superblock on device %s: %m", crypt_get_device_name(cd));
         }
 
-        return crypt_activate_by_volume_key(cd, name, NULL, 0, flags);
+        r = crypt_activate_by_volume_key(cd, name, NULL, 0, flags);
+        if (r < 0)
+                return log_error_errno(r, "Failed to activate tcrypt device %s: %m", crypt_get_device_name(cd));
+
+        return 0;
 }
 
 static int attach_luks_or_plain(struct crypt_device *cd,
@@ -549,22 +554,30 @@ static int attach_luks_or_plain(struct crypt_device *cd,
 
         if (key_file) {
                 r = crypt_activate_by_keyfile_offset(cd, name, arg_key_slot, key_file, arg_keyfile_size, arg_keyfile_offset, flags);
-                if (r < 0) {
-                        log_error_errno(r, "Failed to activate with key file '%s': %m", key_file);
-                        return -EAGAIN;
+                if (r == -EPERM) {
+                        log_error_errno(r, "Failed to activate with key file '%s'. (Key data incorrect?)", key_file);
+                        return -EAGAIN; /* Log actual error, but return EAGAIN */
                 }
+                if (r < 0)
+                        return log_error_errno(r, "Failed to activate with key file '%s': %m", key_file);
         } else {
                 char **p;
 
+                r = -EINVAL;
                 STRV_FOREACH(p, passwords) {
                         if (pass_volume_key)
                                 r = crypt_activate_by_volume_key(cd, name, *p, arg_key_size, flags);
                         else
                                 r = crypt_activate_by_passphrase(cd, name, arg_key_slot, *p, strlen(*p), flags);
-
                         if (r >= 0)
                                 break;
                 }
+                if (r == -EPERM) {
+                        log_error_errno(r, "Failed to activate with specified passphrase. (Passphrase incorrect?)");
+                        return -EAGAIN; /* log actual error, but return EAGAIN */
+                }
+                if (r < 0)
+                        return log_error_errno(r, "Failed to activate with specified passphrase: %m");
         }
 
         return r;
@@ -726,16 +739,11 @@ int main(int argc, char *argv[]) {
                                                          flags);
                         if (r >= 0)
                                 break;
-                        if (r == -EAGAIN) {
-                                key_file = NULL;
-                                continue;
-                        }
-                        if (r != -EPERM) {
-                                log_error_errno(r, "Failed to activate: %m");
+                        if (r != -EAGAIN)
                                 goto finish;
-                        }
 
-                        log_warning("Invalid passphrase.");
+                        /* Passphrase not correct? Let's try again! */
+                        key_file = NULL;
                 }
 
                 if (arg_tries != 0 && tries >= arg_tries) {