static int shared_pagefault(struct vmproc *vmp, struct vir_region *region,
struct phys_region *ph, int write, vfs_callback_t cb,
void *state, int statelen, int *io)
{
struct vir_region *src_region;
struct vmproc *src_vmp;
struct phys_region *pr;
if(getsrc(region, &src_vmp, &src_region) != OK) {
return EINVAL;
}
assert(ph->ph->phys == MAP_NONE);
pb_free(ph->ph);
if(!(pr = physblock_get(src_region, ph->offset))) {
int r;
if((r=map_pf(src_vmp, src_region, ph->offset, write,
NULL, NULL, 0, io)) != OK)
return r;
if(!(pr = physblock_get(src_region, ph->offset))) {
panic("missing region after pagefault handling");
}
}
pb_link(ph, pr->ph, ph->offset, region);
return OK;
}
int
do_mapcache(message *msg)
{
dev_t dev = msg->m_u.m_vmmcp.dev;
u64_t dev_off = (u64_t) msg->m_u.m_vmmcp.dev_offset_pages * VM_PAGE_SIZE;
u64_t ino_off = (u64_t) msg->m_u.m_vmmcp.ino_offset_pages * VM_PAGE_SIZE;
int n;
int bytes = msg->m_u.m_vmmcp.pages * VM_PAGE_SIZE;
struct vir_region *vr;
struct vmproc *caller;
vir_bytes offset;
int io = 0;
if(vm_isokendpt(msg->m_source, &n) != OK) panic("bogus source");
caller = &vmproc[n];
if(bytes < VM_PAGE_SIZE) return EINVAL;
if(!(vr = map_page_region(caller, VM_PAGE_SIZE, VM_DATATOP, bytes,
VR_ANON | VR_WRITABLE, 0, &mem_type_cache))) {
printf("VM: map_page_region failed\n");
return ENOMEM;
}
assert(vr->length == bytes);
for(offset = 0; offset < bytes; offset += VM_PAGE_SIZE) {
struct cached_page *hb;
assert(vr->length == bytes);
assert(offset < vr->length);
if(!(hb = find_cached_page_bydev(dev, dev_off + offset,
msg->m_u.m_vmmcp.ino, ino_off + offset, 1))) {
map_unmap_region(caller, vr, 0, bytes);
return ENOENT;
}
assert(!vr->param.pb_cache);
vr->param.pb_cache = hb->page;
assert(vr->length == bytes);
assert(offset < vr->length);
if(map_pf(caller, vr, offset, 1, NULL, NULL, 0, &io) != OK) {
map_unmap_region(caller, vr, 0, bytes);
printf("VM: map_pf failed\n");
return ENOMEM;
}
assert(!vr->param.pb_cache);
}
memset(msg, 0, sizeof(*msg));
msg->m_u.m_vmmcp_reply.addr = (void *) vr->vaddr;
assert(vr);
#if CACHE_SANITY
cache_sanitycheck_internal();
#endif
return OK;
}
