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Cleanup #26960

mds: avoid modification of const Messages

Added by Patrick Donnelly 4 months ago. Updated 4 months ago.

Status:
New
Priority:
High
Assignee:
-
Category:
Correctness/Safety
Target version:
Start date:
08/17/2018
Due date:
% Done:

0%

Tags:
Backport:
Reviewed:
Affected Versions:
Component(FS):
MDS
Labels (FS):
Pull request ID:

Description

PR #22555 (https://github.com/ceph/ceph/pull/22555/) converted all Message handling to use const to avoid potential errors with re-processing messages that have been changed elsewhere or (in the future) by another thread.

There were a few instances which were not resolved in the interest of getting #22555 done:

~/ceph/src/messages$ git grep mutable
MClientRequest.h:  mutable struct ceph_mds_request_head head; /* XXX HACK! */
MClientRequest.h:    mutable ceph_mds_request_release item;
MClientRequest.h:  mutable vector<Release> releases; /* XXX HACK! */
MClientRequest.h:  mutable bool queued_for_replay = false;
MDirUpdate.h:  mutable int tried_discover = 0; // XXX HACK
MMDSSlaveRequest.h:  mutable __u16 flags; /* XXX HACK for mark_interrupted */
MMDSSlaveRequest.h:  mutable bufferlist straybl;  // stray dir + dentry

Mostly, these are state the MDS uses when reprocessing a Message (after acquiring locks for instance). The MDS should split this state off into a Context and keep the Message purely const.

History

#1 Updated by Patrick Donnelly 4 months ago

  • Tracker changed from Bug to Cleanup

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