I've read through this, and see no issue... +1
On 06/05/09 16:07, Rich.Brown at Sun.COM wrote: > I'm sponsoring the following fast-track for Bob Mastors. > > This case is an update to PSARC 2007/456 Vnode Specific Data and adds > a new field to the vnode structure (in sys/vnode.h): v_vsd_lock. > > The case seeks Minor binding which matches the binding of the original > case. The timer expires on June 12, 2009. > > > Template Version: @(#)sac_nextcase 1.68 02/23/09 SMI > This information is Copyright 2009 Sun Microsystems > 1. Introduction > 1.1. Project/Component Working Name: > VSD locking update > 1.2. Name of Document Author/Supplier: > Author: Bob Mastors > 1.3 Date of This Document: > 05 June, 2009 > 4. Technical Description > > PSARC 2007/456 Vnode Specific Data was created to easily associate > project specific data with a vnode. The current implementation > requires consumers of vsd_get() and vsd_set() to hold the vnode v_lock > mutex across the calls. However, vsd_set() may go to sleep on > kmem_alloc(). This could cause the system to deadlock if the vnode had > dirty pages that needed to be written. This problem is described by: > > 6839233 VSD usage of v_lock could cause deadlock > > The solution adds a new mutex to vnode_t: > > kmutex_t v_vsd_lock; /* protects v_vsd field */ > > Consumers of vsd_get() and vsd_set() would hold v_vsd_lock across the > calls instead of v_lock. There are no lock ordering issues since the > locks are independent and there is no reason to hold both simultaneously. > > Currently, the only ON consumer of vsd_get() and vsd_set() is NFS. > > Exported Interfaces > > Interface Name | Classification | Comments > ================================================================= > | | > v_vsd_lock | Consolidation | New mutex in the vnode structure > | Private | to protect v_vsd field > > 6. Resources and Schedule > 6.4. Steering Committee requested information > 6.4.1. Consolidation C-team Name: > ON > 6.5. ARC review type: FastTrack > 6.6. ARC Exposure: open > > -- --------------------------------------------------------------------- Rick Matthews email: Rick.Matthews at sun.com Sun Microsystems, Inc. phone:+1(651) 554-1518 1270 Eagan Industrial Road phone(internal): 54418 Suite 160 fax: +1(651) 554-1540 Eagan, MN 55121-1231 USA main: +1(651) 554-1500 ---------------------------------------------------------------------
