staging: android: logger: clarify non-update of w_off in do_write_log_from_user

Add comment to explain when w_off is not updated in case of failed second
fragment copy to buffer.

Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tim Bird 2012-02-07 18:34:28 -08:00 committed by Greg Kroah-Hartman
parent 169c843aff
commit 350a195595

View File

@ -330,6 +330,12 @@ static ssize_t do_write_log_from_user(struct logger_log *log,
if (count != len)
if (copy_from_user(log->buffer, buf + len, count - len))
/*
* Note that by not updating w_off, this abandons the
* portion of the new entry that *was* successfully
* copied, just above. This is intentional to avoid
* message corruption from missing fragments.
*/
return -EFAULT;
log->w_off = logger_offset(log, log->w_off + count);