Ubuntu One Client

actions out of limbos lose path info and deadlock

Bug #707576 reported by Lucio Torre
20
This bug affects 3 people
Affects Status Importance Assigned to Milestone
Ubuntu One Client
Fix Released
High
Facundo Batista

Bug Description

syncdaemon.log.2011-01-24_12-05-45:2011-01-24 12:06:13,885 - ubuntuone.SyncDaemon.ActionQueue - DEBUG - Move share:'0e0a3c0d-ddb8-4926-ad71-c33fd6079e6a' node:'4882a59e-d4bc-427a-9d1e-780724742f7b' Move(new_name="u'nataliabidart'", path_from="''", share_id="'0e0a3c0d-ddb8-4926-ad71-c33fd6079e6a'", new_parent_id="'54be8095-7c68-4e65-ad98-d287a855b336'", old_parent_id="'f240382d-b02b-4e1d-b232-02835f5517ae'", path_to="''", node_id="'4882a59e-d4bc-427a-9d1e-780724742f7b'") pathlock acquiring on ('',) (on_parent=True, on_children=True); wait for: 1791
syncdaemon.log.2011-01-24_12-05-45:2011-01-24 12:06:13,896 - ubuntuone.SyncDaemon.ActionQueue - DEBUG - Move share:'0e0a3c0d-ddb8-4926-ad71-c33fd6079e6a' node:'4882a59e-d4bc-427a-9d1e-780724742f7b' Move(new_name="u'nataliabidart'", path_from="''", share_id="'0e0a3c0d-ddb8-4926-ad71-c33fd6079e6a'", new_parent_id="'54be8095-7c68-4e65-ad98-d287a855b336'", old_parent_id="'f240382d-b02b-4e1d-b232-02835f5517ae'", path_to="''", node_id="'4882a59e-d4bc-427a-9d1e-780724742f7b'") pathlock acquiring on ('',) (on_parent=True, on_children=False); wait for: 1792

When a move tries to grab a pathlock it locks on ('',), so al moves block each other and you get queues of thousands of moves (~1800 in this case)

Related branches

lp:~facundo/ubuntuone-client/fix-limbo-paths
Facundo Batista (community): Approve
Lucio Torre (community): Approve
Diff: 521 lines (+135/-69)
7 files modified
contrib/dump_metadata.py (+22/-2)
tests/syncdaemon/test_fsm.py (+47/-25)
tests/syncdaemon/test_localrescan.py (+28/-24)
tests/syncdaemon/test_sync.py (+3/-1)
ubuntuone/syncdaemon/filesystem_manager.py (+25/-9)
ubuntuone/syncdaemon/local_rescan.py (+8/-7)
ubuntuone/syncdaemon/sync.py (+2/-1)
Lucio Torre (lucio.torre)
Changed in ubuntuone-client:
status: New → Confirmed
importance: Undecided → High
tags: added: chicharra chicharra-natty
Revision history for this message
Lucio Torre (lucio.torre) wrote :

when actions are moven out of limbo the path property is lost, so the lock is on ('',)

Revision history for this message
Lucio Torre (lucio.torre) wrote :

and as move will take two locks (source, dest) it will deadlock as the two will be the same.

Revision history for this message
Lucio Torre (lucio.torre) wrote :

to reproduce:
$ cd ~/Ubuntu One/
$ for i in `seq 100`; do > $i; done
<wait for IDLE>
$ for i in `seq 100`; do move $i $i.moved; done
<wait a couple of seconds>
$ u1sdtool -q
<until syncdaemon exits>
$ u1sdtool -s

the queue should now move until reaching the deadlocked moves and freeze there.

Lucio Torre (lucio.torre)
summary: - pathlock for Move grabs everything.
+ actions out of limbos lose path info and deadlock
Facundo Batista (facundo)
Changed in ubuntuone-client:
status: Confirmed → In Progress
Ubuntu One Auto Pilot (otto-pilot)
Changed in ubuntuone-client:
status: In Progress → Fix Committed
Joshua Hoover (joshuahoover)
tags: added: u1-natty-beta
dobey (dobey)
Changed in ubuntuone-client:
status: Fix Committed → Fix Released
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