cvs commit: src/sys/gnu/fs/xfs/FreeBSD xfs_buf.c src/sys/kern kern_lock.c vfs_bio.c src/sys/nfs4client nfs4_vnops.c src/sys/nfsclient nfs_vnops.c src/sys/sys buf.h lock.h lockmgr.h

[Attilio Rao]

attilio     2008-02-13 20:44:19 UTC

  FreeBSD src repository

  Modified files:
    sys/gnu/fs/xfs/FreeBSD xfs_buf.c 
    sys/kern             kern_lock.c vfs_bio.c 
    sys/nfs4client       nfs4_vnops.c 
    sys/nfsclient        nfs_vnops.c 
    sys/sys              buf.h lock.h lockmgr.h 
  Log:
  - Add real assertions to lockmgr locking primitives.
    A couple of notes for this:
    * WITNESS support, when enabled, is only used for shared locks in order
      to avoid problems with the "disowned" locks
    * KA_HELD and KA_UNHELD only exists in the lockmgr namespace in order
      to assert for a generic thread (not curthread) owning or not the
      lock.  Really, this kind of check is bogus but it seems very
      widespread in the consumers code.  So, for the moment, we cater this
      untrusted behaviour, until the consumers are not fixed and the
      options could be removed (hopefully during 8.0-CURRENT lifecycle)
    * Implementing KA_HELD and KA_UNHELD (not surported natively by
      WITNESS) made necessary the introduction of LA_MASKASSERT which
      specifies the range for default lock assertion flags
    * About other aspects, lockmgr_assert() follows exactly what other
      locking primitives offer about this operation.
  
  - Build real assertions for buffer cache locks on the top of
    lockmgr_assert().  They can be used with the BUF_ASSERT_*(bp)
    paradigm.
  
  - Add checks at lock destruction time and use a cookie for verifying
    lock integrity at any operation.
  
  - Redefine BUF_LOCKFREE() in order to not use a direct assert but
    let it rely on the aforementioned destruction time check.
  
  KPI results evidently broken, so __FreeBSD_version bumping and
  manpage update result necessary and will be committed soon.
  
  Side note: lockmgr_assert() will be used soon in order to implement
  real assertions in the vnode namespace replacing the legacy and still
  bogus "VOP_ISLOCKED()" way.
  
  Tested by:      kris (earlier version)
  Reviewed by:    jhb
  
  Revision  Changes    Path
  1.4       +3 -5      src/sys/gnu/fs/xfs/FreeBSD/xfs_buf.c
  1.124     +117 -28   src/sys/kern/kern_lock.c
  1.536     +11 -13    src/sys/kern/vfs_bio.c
  1.41      +2 -3      src/sys/nfs4client/nfs4_vnops.c
  1.281     +2 -3      src/sys/nfsclient/nfs_vnops.c
  1.200     +27 -6     src/sys/sys/buf.h
  1.71      +1 -0      src/sys/sys/lock.h
  1.62      +24 -0     src/sys/sys/lockmgr.h