-E sync: reform logic. Prequery file position, jump over error hole.

[tfcrypt.git] / tfc_error.c

diff --git a/tfc_error.c b/tfc_error.c
index 048c0bb480a17e618f0161cf88426e090d234150..e33131504fa1051b22b1f419202fd137b0d23a97 100644 (file)
--- a/tfc_error.c
+++ b/tfc_error.c
@@ -212,9 +212,13 @@ void usage(void)
        tfc_say("    cont: print error if not quiet, then continue,");
        tfc_say("      no action to pad missing data is attempted.");
        tfc_say("      may be dangerous when working with block devices.");
-       tfc_say("    sync: print error if not quiet, then continue.");
+       tfc_say("    sync: print error if not quiet, then continue,");
        tfc_say("      pad missing data block with zeroes.");
-       tfc_say("      note that sync works only with read errors!");
+       tfc_say("    lsync: same as sync, but does not use SEEK_SET logic,");
+       tfc_say("      lsync uses only relative seek operations, and does not prequery");
+       tfc_say("      the current file position for exact offsets, which maybe unsafe.");
+       tfc_say("      For this reason, it is HIGHLY recommended to use sync instead!");
+       tfc_say("      Note that both sync and lsync work only with read errors!");
        tfc_say("  default error action is exit with printing status if not quiet.");
        tfc_say("  -E xall: turn on error actions above for all errors, not just EIO errors.");
        tfc_say("    This must be a separate option given before usual -E how option.");