Created attachment 1766492 [details] C program to test fsync hang. Description: The issue was found by Xavi when working on customer BZ 1915037. See https://bugzilla.redhat.com/show_bug.cgi?id=1915037#c7 for more details. We do not know yet how the issue can lead to VM pause but nevertheless, the fix is needed as a first step in reducing the occurence of the problem. Reproducer: 1.Create a 1x3 volume with RHHI volume options enabled (virt profile). 2. Run the attached program from two different fuse mounts on the same volume, on the same file. 3. The program writes + fsyncs the file in a loop. It can be observed that without the fix, fsync on the 2nd mount will be hung forever.
Verified with RHGS 3.5.5 interim build ( glusterfs-6.0-59.el8rhgs ) 1. First part of verification with RHGS 3.5.4 ( glusterfs-6.0-56.2.el8rhgs ) a. Ran the c program from one host with file name on the replicate gluster volume as argument b. Ran the c program from another host with the same file on the fuse mounted gluster volume Observed that the fsync is hung 2. Now upgraded the glusterfs to 6.0-59.el8rhgs, repeated the same test as above. fsync hang was not observed 3. Ran the regression tests
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (RHGS 3.5.z Batch Update 5 glusterfs bug fix and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2021:3729
*** Bug 2276826 has been marked as a duplicate of this bug. ***