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Re: Where does a vnode gets dirty?

Note that clean pages in writable files are mapped as read-only (see
UVM_OBJ_NEEDS_WRITEFAULT() in uvm_fault.c).  Write-accessing such
pages causes protection fault, then calls uvm_fault() -> pgo_get() ->
genfs_getpages(), where pages are marked dirty.  I think this is same
for UBC except that pages are mapped indirectly in UBC windows (kernel

On Fri, Aug 19, 2011 at 10:29 AM, Emmanuel Dreyfus <> 
> Hello
> When copying data to a vnode using ubc_alloc() ubc_uiomove() and
> ubc_release(), where does the kernel notes that data is dirty and will
> need to be written by VOP_PUTPAGE? Is it the responsability of the
> caller to request it (how?), or is it done somewhere in UBC?
> --
> Emmanuel Dreyfus

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