On 04/02/2014 01:00 AM, Tom Robinson wrote:
On 01/04/14 17:49, Alexandru Chiscan wrote:
On 04/01/2014 06:27 AM, Keith Keller wrote:
On 2014-04-01, Tom Robinson tom.robinson@motec.com.au wrote:
Now, I understand that Red Hat (and therefore CentOS) backport many upstr= eam features into the stock kernel so how can I be sure that kernel 2.6.32-431.11.2.el6 has write bar= rier support?
Take a look here: https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/...
Regards, Lec
Thanks Lec, I did read this already. It does address filesystems but not LVM. Are write barriers enabled for LVM? Write barriers need to be implemented through the entire stack for them to work. If you have ext4 on LVM on MD not having them on LVM would break the chain. N'est-ce pas?
from the kernel changelog (https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11...) the barrier support for filesystems, lvm (dm) and md is active from 2.6.32-82-el6
-[fs]jbd2: replace barriers with explicit flush and FUA usage https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/fs-jbd2-replace-barriers-with-explicit-flush-and-FUA-usage.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[fs]jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/fs-jbd2-Modify-ASYNC_COMMIT-code-to-not-rely-on-queue-draining-on-barrier.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[fs]jbd: replace barriers with explicit flush and FUA usage https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/fs-jbd-replace-barriers-with-explicit-flush-and-FUA-usage.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[fs]gfs2: replace barriers with explicit flush and FUA usage https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/fs-gfs2-replace-barriers-with-explicit-flush-and-FUA-usage.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[fs]btrfs: replace barriers with explicit flush and FUA usage https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/fs-btrfs-replace-barriers-with-explicit-flush-and-FUA-usage.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[fs]xfs: replace barriers with explicit flush and FUA usage https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/fs-xfs-replace-barriers-with-explicit-flush-and-FUA-usage.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]pass gfp_mask and flags to sb_issue_discard https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-pass-gfp_mask-and-flags-to-sb_issue_discard.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]disallow FS recursion from sb_issue_discard allocation https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-disallow-FS-recursion-from-sb_issue_discard-allocation.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[dm]convey that all flushes are processed as empty https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/dm-convey-that-all-flushes-are-processed-as-empty.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[dm]fix locking context in queue_io() https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/dm-fix-locking-context-in-queue_io.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[dm]relax ordering of bio-based flush implementation https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/dm-relax-ordering-of-bio-based-flush-implementation.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[dm]implement REQ_FLUSH/FUA support for request-based dm https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/dm-implement-REQ_FLUSH-FUA-support-for-request-based-dm.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[dm]implement REQ_FLUSH/FUA support for bio-based dm https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/dm-implement-REQ_FLUSH-FUA-support-for-bio-based-dm.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]make __blk_rq_prep_clone() copy most command flags https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-make-__blk_rq_prep_clone-copy-most-command-flags.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[md]implment REQ_FLUSH/FUA support https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/md-implment-REQ_FLUSH-FUA-support.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[virt]virtio_blk: drop REQ_HARDBARRIER support https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/virt-virtio_blk-drop-REQ_HARDBARRIER-support.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]loop: implement REQ_FLUSH/FUA support https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-loop-implement-REQ_FLUSH-FUA-support.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]use REQ_FLUSH in blkdev_issue_flush() https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-use-REQ_FLUSH-in-blkdev_issue_flush.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]update documentation for REQ_FLUSH / REQ_FUA https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-update-documentation-for-REQ_FLUSH-REQ_FUA.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]make sure FSEQ_DATA request has the same rq_disk as the original https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-make-sure-FSEQ_DATA-request-has-the-same-rq_disk-as-the-original.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]kick queue after sequencing REQ_FLUSH/FUA https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-kick-queue-after-sequencing-REQ_FLUSH-FUA.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]initialize flush request with WRITE_FLUSH instead of REQ_FLUSH https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-initialize-flush-request-with-WRITE_FLUSH-instead-of-REQ_FLUSH.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]simplify queue_next_fseq https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-simplify-queue_next_fseq.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]filter flush bio's in __generic_make_request() https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-filter-flush-bio-s-in-__generic_make_request.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]preserve RHEL6.0 struct request_queue kABI https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-preserve-RHEL6-0-struct-request_queue-kABI.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199] -[block]implement REQ_FLUSH/FUA based interface for FLUSH/FUA requests https://access.redhat.com/knowledge/sources/source_rpms/kernel-2.6.32-431.11.2.el6/patches/block-implement-REQ_FLUSH-FUA-based-interface-for-FLUSH-FUA-requests.patch (Mike Snitzer) [635199 https://bugzilla.redhat.com/show_bug.cgi?id=635199]