Differential D59737

fusefs: fix a deadlock caused by daemons that never initialize
ClosedPublic
Actions

Authored by asomers on Wed, Sep 16, 6:36 PM.

Tags

None

Referenced Files

	F174262714: D59737.diff
	Thu, Oct 1, 8:16 PM

	F174226612: D59737.diff
	Thu, Oct 1, 12:48 PM

	F174162385: D59737.diff
	Thu, Oct 1, 1:18 AM

	Unknown Object (File)
	Wed, Sep 30, 7:05 AM

	Unknown Object (File)
	Tue, Sep 29, 1:53 PM

	Unknown Object (File)
	Tue, Sep 29, 10:15 AM

	Unknown Object (File)
	Tue, Sep 29, 6:15 AM

	Unknown Object (File)
	Mon, Sep 28, 8:06 PM

View All 33 Files

Subscribers

Details

Reviewers

Commits

rG0bd6348b52e1: fusefs: fix a deadlock caused by daemons that never initialize

Summary

If a daemon never responds to FUSE_INIT, but some process attempts to
access the mountpoint, and a different process (possibly the daemon
itself) attempts to unmount, a deadlock would result.

Fix this bug by blocking any thread that enters fuse_vfsop_root until
the daemon responds to FUSE_INIT or it times out. That will block any
thread attempting to lookup a path in the fuse mountpoint, before it
even gets to fuse VOPs. Remove less thorough initialization checks in
fuse_ticket_fetch and fuse_vnop_access that are no longer necessary.
And add a test case.

PR: 287431
MFC after: 2 weeks
Sponsored by: ConnectWise

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Passed

Unit

No Test Coverage

Build Status

Buildable 76991
Build 73874: arc lint + arc unit

Event Timeline

asomers created this revision.Wed, Sep 16, 6:36 PM

Herald added a subscriber: imp. · View Herald TranscriptWed, Sep 16, 6:36 PM

Harbormaster completed remote builds in B76991: Diff 186904.Wed, Sep 16, 6:36 PM

asomers requested review of this revision.Wed, Sep 16, 6:36 PM

js added inline comments.Mon, Sep 21, 9:22 AM

sys/fs/fuse/fuse_vfsops.c
645	s/suceed/succeed/

This revision was not accepted when it landed; it landed in state Needs Review.Wed, Sep 23, 10:32 PM

Closed by commit rG0bd6348b52e1: fusefs: fix a deadlock caused by daemons that never initialize (authored by asomers). · Explain Why

This revision was automatically updated to reflect the committed changes.

asomers added a commit: rG0bd6348b52e1: fusefs: fix a deadlock caused by daemons that never initialize.

Revision Contents
Changeset List

Path

Size

sys/

fs/

fuse/

1 line

24 lines

31 lines

14 lines

tests/

sys/

fs/

fusefs/

2 lines

8 lines

86 lines

2 lines

2 lines

Diff 186904

sys/fs/fuse/fuse_ipc.h

Loading...

sys/fs/fuse/fuse_ipc.c

Loading...

sys/fs/fuse/fuse_vfsops.c

Loading...

sys/fs/fuse/fuse_vnops.c

Loading...

tests/sys/fs/fusefs/mockfs.hh

Loading...

tests/sys/fs/fusefs/mockfs.cc

Loading...

tests/sys/fs/fusefs/pre-init.cc

Loading...

tests/sys/fs/fusefs/utils.hh

Loading...

tests/sys/fs/fusefs/utils.cc

Loading...