This bug is to track the RHEL2.1 variant of Bug 147969. From that bug report: Description of problem: Calling msync(p, size, MS_SYNC) on a memory mapped file is not waiting for the data to be flushed to disk [eg a 128Mb chunk of data is claiming to be flushed in 1-2ms : cf 2.4.21-15 / 2.6.8-1.521 where the same test code takes 2-3s to do this] This means that there is no way for code to know that the data it has just written to a memory mapped file has actually made it to disk. Version-Release number of selected component (if applicable): kernel-2.4.21-20.EL and kernel-2.4.21-27.0.2.EL How reproducible: Always Steps to Reproduce: 1.mmap a (large-ish) file 2.write some data into the memory region 3.call msync with the MS_SYNC option 4.reboot the PC by hitting the power switch once msync has completed... [or time how long it takes to sync the data] 5.look at the contents of the file Actual Results: Data missing from file on disk (was present in file (ie disk buffers) prior to hitting power) Expected Results: msync should wait for the data to be written to disk when the MS_SYNC flag is used.
A fix for this problem has just been committed to the RHEL2.1 U7 patch pool this evening (in kernel version 2.4.9-61).
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2005-283.html