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/* Implementation of memory_object_data_unlock for pager library
Copyright (C) 1994 Free Software Foundation
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Called by the kernel to request a lock on memory. */
/* We provide all data read-write except for "holes". Therefore,
lock requests should only happen for holes, and this routine does the
allocation. */
kern_return_t
seqnos_memory_object_data_unlock (mach_port_t object,
mach_port_seqno_t seqno,
mach_port_t control,
vm_offset_t offset,
vm_size_t length,
vm_prot_t access)
{
struct pager *p;
volatile int err;
struct inode *volatile ip;
daddr_t newblk;
daddr_t vblkno;
daddr_t *slot;
daddr_t *table;
if (!(p = check_port_type (object, PT_PAGER)))
return EOPNOTSUPP;
mutex_lock (&p->interlock);
wait_for_seqno (p, seqno);
release_seqno (p);
mutex_unlock (&p->interlock);
if (p->pager_state != NORMAL)
{
printf ("pager in wrong state for unlock\n");
goto out;
}
if (control != p->memobjcntl)
{
printf ("incg data unlock: wrong control port");
goto out;
}
/* The only thing we ever block is writes */
if ((access & VM_PROT_WRITE) == 0)
{
printf ("incg data unlock: not unlock writes");
goto out;
}
if (offset % __vm_page_size)
{
printf ("incg data unlock: misaligned request");
goto out;
}
if (length != __vm_page_size)
{
printf ("incg data request: bad length size");
goto out;
}
if (shutting_down)
{
/* Let the kernel stew. */
return EIEIO;
}
err = pager_unlock_page (p->upi, offset);
if (!err)
/* We can go ahead and release the lock. */
lock_object (p, offset, length, MEMORY_OBJECT_RETURN_NONE, 0,
VM_PROT_NONE, 0);
else
{
/* Flush the page, and set a bit so that m_o_data_request knows
to issue an error. */
lock_object (p, offset, length, MEMORY_OBJECT_RETURN_NONE, 1,
VM_PROT_WRITE, 1);
mark_next_request_error (p, offset, length, err);
}
out:
done_with_port (p);
return 0;
}
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