Boris Popov 67e871664b Add a lock structure to vnode structure. Previously it was either allocated ... separately (nfs, cd9660 etc) or keept as a first element of structure referenced by v_data pointer(ffs). Such organization leads to known problems with stacked filesystems. From this point vop_no*lock*() functions maintain only interlock lock. vop_std*lock*() functions maintain built-in v_lock structure using lockmgr(). vop_sharedlock() is compatible with vop_stdunlock(), but maintains a shared lock on vnode. If filesystem wishes to export lockmgr compatible lock, it can put an address of this lock to v_vnlock field. This indicates that the upper filesystem can take advantage of it and use single lock structure for entire (or part) of stack of vnodes. This field shouldn't be examined or modified by VFS code except for initialization purposes. Reviewed in general by: mckusick		2000-09-25 15:24:04 +00:00
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ext2fs	Add a lock structure to vnode structure. Previously it was either allocated	2000-09-25 15:24:04 +00:00