[php-src] Issue #10548: copy() fails on cifs mounts because of incorrect length (cfr_max) specified in streams.c:1584 copy_file_range()

Issue: https://github.com/php/php-src/issues/10548 Author: knowsshit ### Description I noticed that Wordpress on Azure Web App with PHP 8.2 stack on Linux fails to install and upgrade anything because copy() fails when trying to copy files from /home/site/wwwroot/wp-content/upgrade/ to /home/site/wwwroot/wp-content/plugins/. /home/ is a cifs mount. The following code: ```php if ( ! copy( '/home/site/wwwroot/sourcefile', '/home/site/wwwroot/destfile' ) ) echo "copy failed\n"; ``` Resulted in this output: ``` copy failed ``` But I expected this output instead: (no output and successful file copy) ``` ``` I did a strace: ``` copy_file_range(5, NULL, 6, NULL, 9223372036854775807, 0) = -1 EIO (Input/output error) ``` Here we can see that PHP specifies a very large length value for the fifth argument, and that copy_file_range() results in an I/O error. So I guess the large length value works fine on most filesystems, but not on cifs. PHP source from php-8.2.2/main/streams/streams.c lines 1576,1577,1584: ``` /* clamp to INT_MAX to avoid EOVERFLOW */ const size_t cfr_max = MIN(maxlen, (size_t)SSIZE_MAX); ssize_t result = copy_file_range(src_fd, NULL, dest_fd, NULL, cfr_max, 0); ``` I took the copy_file_range() example from https://man7.org/linux/man-pages/man2/copy_file_range.2.html that specifies the correct length by getting the file size with fstat(). Compiling it and running it with strace shows successful copy of the same files within the same /home cifs mount: ``` copy_file_range(3, NULL, 4, NULL, 11, 0) = 11 ``` The solution would be to do the same as the example on https://man7.org/linux/man-pages/man2/copy_file_range.2.html and get the correct file size of the source file and specify it as the fifth argument to copy_file_range(). Additional info (some parts replaced with ... for privacy): ``` # php -v PHP 8.2.0 (cli) (built: Dec 27 2022 20:38:32) (NTS) Copyright (c) The PHP Group Zend Engine v4.2.0, Copyright (c) Zend Technologies with Zend OPcache v8.2.0, Copyright (c), by Zend Technologies # egrep '(Version|Features)' /proc/fs/cifs/DebugData /proc/fs/cifs/DebugData:CIFS Version 2.10 /proc/fs/cifs/DebugData:Features: DFS,FSCACHE,STATS,DEBUG,ALLOW_INSECURE_LEGACY,WEAK_PW_HASH,CIFS_POSIX,UPCALL(SPNEGO),XATTR,ACL # mount | grep home //10.0.0.1/volume-...-default/... on /home type cifs (rw,relatime,vers=default,cache=strict,username=dummyadmin_...,domain=,uid=0,noforceuid,gid=0,noforcegid,addr=10.0.0.1,file_mode=0777,dir_mode=0777,soft,nounix,mapposix,mfsymlinks,noperm,rsize=1048576,wsize=1048576,echo_interval=60,actimeo=1) # uname -a Linux 3f6c4cc7fa2c 4.15.0-191-generic #202-Ubuntu SMP Thu Aug 4 01:49:29 UTC 2022 x86_64 GNU/Linux # cat /etc/debian_version 11.6 # cat /etc/motd _____ / _ \ __________ _________ ____ / /_\ \\___ / | \_ __ \_/ __ \ / | \/ /| | /| | \/\ ___/ \____|__ /_____ \____/ |__| \___ > \/ \/ \/ A P P S E R V I C E O N L I N U X Documentation: http://aka.ms/webapp-linux PHP quickstart: https://aka.ms/php-qs PHP version : 8.2.0 Note: Any data outside '/home' is not persisted ``` ### PHP Version PHP 8.2 ### Operating System Debian 11.6