RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Description of problem:

Enterprise storage arrays typically support discards in very large chunks. Our existing implementation issues the discard commands in multiples of small, file
system block units (4KB typically).  Arrays often ignore small requests so we need to support large, array specific minimum discards to enable this feature for them.

Additional info:

This has been fixed in upstream kernel 2.6.37-rc1. The fix involves subsequent commits:

77ca6cdf0ab8a42f481ec997911bc89e79138723
367a51a339020ba4d9edb0ce0f21d65bd50b00c9
7360d1731e5dc78aec867e65e55f9fb58782b5fe
27ee40df2b17c84aa7855907df12befe6869b7a7

Created attachment 463085 [details]
Testcase (patch for xfstests-dev)

It was already posted for inclusion into RHEL6.1. I have tested it myself with xfstests-dev, unfortunately the test is not upstream yet, but you can use attached patch for latest xfstests-dev.

Thanks!

-Lukas

This BZ should be ready for 6.1. Can we get QE & PM acks please?

This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux maintenance release. Product Management has 
requested further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed 
products. This request is not yet committed for inclusion in an Update release.

Patch(es) available on kernel-2.6.32-112.el6

Verified sanityonly in 2.6.32-106.el6.

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 therefore 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-2011-0542.html