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Bug #11052

ZFS Reads may result in unneccesary calls to zil_commit

Added by Jerry Jelinek 4 months ago. Updated 3 months ago.

Status:
Closed
Priority:
Normal
Assignee:
Category:
zfs - Zettabyte File System
Start date:
2019-05-21
Due date:
% Done:

100%

Estimated time:
Difficulty:
Medium
Tags:
needs-triage

Description

ZoL commit 2efea7c82c5.

ZFS supports O_RSYNC for read operations and when specified will ensure
the same level of data integrity that O_DSYNC and O_SYNC provides for
writes. O_RSYNC by itself has no effect so it must be combined with
either O_DSYNC or O_SYNC. However, many platforms don't support O_RSYNC
and have mapped O_SYNC to mean O_RSYNC within ZFS. This is incorrect
and causes unnecessary calls to zil_commit. Only platforms which
support O_RSYNC should implement the zil_commit functionality in the
read code path.

History

#1

Updated by Jerry Jelinek 4 months ago

Overlaps with ZoL
376994828f Fix NULL pointer when O_SYNC read in snapshot
So port that fix as well.

#2

Updated by Jerry Jelinek 3 months ago

This work is essentially a no-op on illumos, but still nice to have to keep the code in sync.

#3

Updated by Electric Monk 3 months ago

  • Status changed from New to Closed
  • % Done changed from 0 to 100

git commit da7753c428994e4e6c715886c93d7b49390c3705

commit  da7753c428994e4e6c715886c93d7b49390c3705
Author: George Wilson <gwilson@zfsmail.com>
Date:   2019-06-28T16:27:00.000Z

    11052 ZFS Reads may result in unneccesary calls to zil_commit
    Portions contributed by: Jerry Jelinek <jerry.jelinek@joyent.com>
    Reviewed by: Matt Ahrens <mahrens@delphix.com>
    Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
    Reviewed by: Toomas Soome <tsoome@me.com>
    Reviewed by: Andy Fiddaman <andy@omniosce.org>
    Approved by: Dan McDonald <danmcd@joyent.com>

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