Bug #79633 [Opn->Fbk]: readdir skips entries

Edit report at https://bugs.php.net/bug.php?id=79633&edit=1 ID: 79633 Updated by: cmb@php.net Reported by: keith at ksmith dot com Summary: readdir skips entries -Status: Open +Status: Feedback Type: Bug Package: Directory function related Operating System: Ubuntu 18.04, Others PHP Version: Irrelevant -Assigned To: +Assigned To: cmb Block user comment: N Private report: N New Comment: When readdir() returns "0", the loop is terminated. Use === to check that the function does not return FALSE. Would that solve the issue? Previous Comments: ------------------------------------------------------------------------ [2020-05-26 05:54:17] keith at ksmith dot com This has something to do with using the "stream" wrapper around the call. Digging in the code I find "opendir(3)" eventually (about 5 layers down) is (appears to be) called from a #define VCWD_OPENDIR(path) opendir(path). I'm not familiar with all the indirection on the calls in between, and the requisite #if's for various OS's, versions and such. I'm guessing there is a small size or length typo or oddity around some buffering. A test sequence ... -- Create a folder with 5 numbered directories -- its on a small XFS filesystem, plenty of free space [root@vbox-2] /home/keith<319>mkdir -p /foo/bar [root@vbox-2] /home/keith<320>df -h /foo/bar Filesystem Size Used Avail Use% Mounted on /dev/md0 56G 34G 23G 60% / [root@vbox-2] /home/keith<321>cat /proc/mounts | grep md0 /dev/md0 / xfs rw,relatime,attr2,inode64,noquota 0 0 [root@vbox-2] /home/keith<322>mkdir /foo/bar/0 /foo/bar/1 /foo/bar/2 /foo/bar/3 /foo/bar/4 /foo/bar/5 [root@vbox-2] /home/keith<323>ls /foo/bar 0 1 2 3 4 5 -- PHP script/readdir finds no folders (but they are there) [root@vbox-2] /home/keith<324>/nas-3/admin/bin/PHP-DIR-test.php /foo/bar Array ( [0] => . [1] => .. ) [root@vbox-2] /home/keith<325>ls -l /foo/bar total 0 drwxr-xr-x 2 root root 6 May 25 22:40 0 drwxr-xr-x 2 root root 6 May 25 22:40 1 drwxr-xr-x 2 root root 6 May 25 22:40 2 drwxr-xr-x 2 root root 6 May 25 22:40 3 drwxr-xr-x 2 root root 6 May 25 22:40 4 drwxr-xr-x 2 root root 6 May 25 22:40 5 [root@vbox-2] /home/keith<326>/nas-3/admin/bin/PHP-DIR-test.php /foo/bar Array ( [0] => . [1] => .. ) -- If we rename the VERY FIRST directory in the folder, magic happens:: [root@vbox-2] /home/keith<327>mv /foo/bar/0 /foo/bar/00 [root@vbox-2] /home/keith<328>/nas-3/admin/bin/PHP-DIR-test.php /foo/bar Array ( [0] => . [1] => .. [2] => 00 [3] => 1 [4] => 2 [5] => 3 [6] => 4 [7] => 5 ) -- And if we put it back it gets weird again [root@vbox-2] /home/keith<329>mv /foo/bar/00 /foo/bar/0 [root@vbox-2] /home/keith<330>/nas-3/admin/bin/PHP-DIR-test.php /foo/bar Array ( [0] => . [1] => .. [2] => 1 [3] => 2 [4] => 3 [5] => 4 [6] => 5 ) -- The script and PHP version. [root@vbox-2] /home/keith<331>cat /nas-3/admin/bin/PHP-DIR-test.php #!/usr/bin/php <?php if ( $argc > 1 ) { $cur_folder = $argv[1]; } else { $cur_folder = "/volume1/media/testfolder"; } $dirp = opendir($cur_folder); while($entry = readdir($dirp)) { clearstatcache(); $path = sprintf("%s/%s",$cur_folder,$entry); if(is_dir($path)) { $entry_list[] = $entry; } } sort($entry_list); print_r($entry_list); ?> [root@vbox-2] /home/keith<332>php --version PHP 7.3.14-1~deb10u1 (cli) (built: Feb 16 2020 15:07:23) ( NTS ) Copyright (c) 1997-2018 The PHP Group Zend Engine v3.3.14, Copyright (c) 1998-2018 Zend Technologies with Zend OPcache v7.3.14-1~deb10u1, Copyright (c) 1999-2018, by Zend Technologies ------------------------------------------------------------------------ [2020-05-26 02:11:12] keith at ksmith dot com This issue occurs direct, and over NFS. Tested with various versions of PHP 5 and 7, available with Debian, and on a Synology NAS. Extending to the character range [0-9,A-Z] for the folder names leaves out a number of other single letter named folders. Code indicates function calls php_stream_readdir which in turn calls php_stream_read, rather than the C language readdir function. I will likely hack up some code to use the 'C' library directly, I'm not sure why that call is so indirect/obfuscated. ------------------------------------------------------------------------ [2020-05-26 02:03:17] keith at ksmith dot com Description: ------------ root@nas-2:/volume1/admin/bin# mkdir /volume1/media/testfolder/0 root@nas-2:/volume1/admin/bin# mkdir /volume1/media/testfolder/1 root@nas-2:/volume1/admin/bin# mkdir /volume1/media/testfolder/2 root@nas-2:/volume1/admin/bin# mkdir /volume1/media/testfolder/3 root@nas-2:/volume1/admin/bin# mkdir /volume1/media/testfolder/4 root@nas-2:/volume1/admin/bin# mkdir /volume1/media/testfolder/5 root@nas-2:/volume1/admin/bin# ls /volume1/media/testfolder 0 1 2 3 4 5 root@nas-2:/volume1/admin/bin# php PHP-test.php Array ( [0] => .. [1] => 1 [2] => 3 [3] => 4 [4] => 5 ) See Code below Test script: --------------- #!/usr/bin/php <?php $cur_folder = "/volume1/media/testfolder"; $dirp = opendir($cur_folder); while($entry = readdir($dirp)) { $entry_list[] = $entry; } sort($entry_list); print_r($entry_list); ?> Expected result: ---------------- I would expect to see the entries: "." and "2" ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79633&edit=1