Bug #60232 [Com]: Wrong lock support detection for streams

Edit report at https://bugs.php.net/bug.php?id=60232&edit=1 ID: 60232 Comment by: karsten at typo3 dot org Reported by: goetas at lignano dot it Summary: Wrong lock support detection for streams Status: Not a bug Type: Bug Package: Streams related Operating System: ubuntu PHP Version: 5.3.8 Block user comment: N Private report: N New Comment: I have just been bitten by this issue, and for all I can tell the reasoning behind what goetas writes makes me think "yeah, right!". Could someone *please* reevaluate the "not a bug" statements? Previous Comments: ------------------------------------------------------------------------ [2011-11-29 15:15:07] goetas at lignano dot it This is extracted from standard/file.c starting from line 618. I have commented some fundamental parts for this bug. ... } else if (flags & LOCK_EX) { // exclusive lock? // the following lines does not check any real stream locking support // this code will block all protocols // that use LOCK_EX, except file:// // are we using a stream protocol? eg: file:// http:// custom:// if (php_memnstr(filename, "://", sizeof("://") - 1, filename + filename_len)) { // if the protocol is not file:// throw an error if (strncasecmp(filename, "file://", sizeof("file://") - 1)) { php_error_docref(NULL TSRMLS_CC, E_WARNING, "Exclusive locks may only be set for regular files"); RETURN_FALSE; } } mode[0] = 'c'; } // the following lines can not be reached by any other //protocol using LOCK_EX, except file:// mode[2] = '\0'; stream = php_stream_open_wrapper_ex(filename, mode, ((flags & PHP_FILE_USE_INCLUDE_PATH) ? USE_PATH : 0) | ENFORCE_SAFE_MODE | REPORT_ERRORS, NULL, context); if (stream == NULL) { RETURN_FALSE; } // better locking check if (flags & LOCK_EX && (!php_stream_supports_lock(stream) || php_stream_lock(stream, LOCK_EX))) { php_stream_close(stream); php_error_docref(NULL TSRMLS_CC, E_WARNING, "Exclusive locks are not supported for this stream"); RETURN_FALSE; } According to current implementation of file_put_contents there is no way to use exclusive locks support with a custom protocol wrapper. ------------------------------------------------------------------------ [2011-11-29 13:30:09] iliaa@php.net Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php The stream_support_locking() merely checks if stream->fd is present, it does not "actually" check if locking is supported. Therefor the check is actually correct. ------------------------------------------------------------------------ [2011-11-16 19:26:12] goetas at lignano dot it in file.c there is a double check for stream locking support, but the first check is done in the worong way. i'm not a c programmer, i think that should be done somethink like this if(file_lock) then if(is_stream && !stream_support_locking) then throw error endif endif ------------------------------------------------------------------------ [2011-11-16 12:32:17] felipe@php.net The first check was introduced to fix the issue reported in bug #44501. ------------------------------------------------------------------------ [2011-11-07 12:04:03] goetas at lignano dot it Description: ------------ I have implemented my own stream that support locking (defined the function stream_lock). when use: file_put_contents("sqlfile://www.pppoa.it/x", "", LOCK_EX); I get this error: Exclusive locks may only be set for regular files I've take a look into PHP_5_3/ext/standard/file.c, and at line 620 there is a check, that generates this error. Few lines after, at line 635 there is a second check, for stream lock support. But these lines of code (635...) is newer reachable because all operations on stream that require locking will stop on line 623. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=60232&edit=1