Date: Thu, 13 Apr 2023 00:23:18 UTC
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=270810 Bug ID: 270810 Summary: munmap does not always sync the underlying file Product: Base System Version: 13.1-RELEASE Hardware: amd64 OS: Any Status: New Severity: Affects Many People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: email@example.com the man page explicitly states that The msync() system call is usually not needed however when doing the following sequence open() mmap() close() do something that writes to the memory mapped region munmap() program exits immediately, the underlying file is not reliably updated when on an nfs mount. Random pages are not written. Calling msync before unmapping solves this, but the man pages do not indicate that this is necessary. The problem does not seem to occur if the program performs more IO after the munmap before exiting. The problem never occurs when the mapped file is on a local file system. nfs server of this test was running FreeBSD 12.1-RELEASE-p3 nfs clients tested FreeBSD 12.1-RELEASE-p3 and FreeBSD 13.1-RELEASE-p2 -- You are receiving this mail because: You are the assignee for the bug.