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; }
static int cache_pagefault(struct vmproc *vmp, struct vir_region *region, struct phys_region *ph, int write, vfs_callback_t cb, void *state, int len, int *io) { vir_bytes offset = ph->offset; assert(ph->ph->phys == MAP_NONE); assert(region->param.pb_cache); pb_unreferenced(region, ph, 0); pb_link(ph, region->param.pb_cache, offset, region); region->param.pb_cache = NULL; return OK; }
static int mappedfile_pagefault(struct vmproc *vmp, struct vir_region *region, struct phys_region *ph, int write, vfs_callback_t cb, void *state, int statelen, int *io) { u32_t allocflags; int procfd = region->param.file.fdref->fd; allocflags = vrallocflags(region->flags); assert(ph->ph->refcount > 0); assert(region->param.file.inited); assert(region->param.file.fdref); assert(region->param.file.fdref->dev != NO_DEV); /* Totally new block? Create it. */ if(ph->ph->phys == MAP_NONE) { struct cached_page *cp; u64_t referenced_offset = region->param.file.offset + ph->offset; if(region->param.file.fdref->ino == VMC_NO_INODE) { cp = find_cached_page_bydev(region->param.file.fdref->dev, referenced_offset, VMC_NO_INODE, 0, 1); } else { cp = find_cached_page_byino(region->param.file.fdref->dev, region->param.file.fdref->ino, referenced_offset, 1); } if(cp) { int result = OK; pb_unreferenced(region, ph, 0); pb_link(ph, cp->page, ph->offset, region); if(roundup(ph->offset+region->param.file.clearend, VM_PAGE_SIZE) >= region->length) { result = cow_block(vmp, region, ph, region->param.file.clearend); } else if(result == OK && write) { result = cow_block(vmp, region, ph, 0); } return result; } if(!cb) { #if 0 printf("VM: mem_file: no callback, returning EFAULT\n"); #endif sys_diagctl_stacktrace(vmp->vm_endpoint); return EFAULT; } if(vfs_request(VMVFSREQ_FDIO, procfd, vmp, referenced_offset, VM_PAGE_SIZE, cb, NULL, state, statelen) != OK) { printf("VM: mappedfile_pagefault: vfs_request failed\n"); return ENOMEM; } *io = 1; return SUSPEND; } if(!write) { #if 0 printf("mappedfile_pagefault: nonwrite fault?\n"); #endif return OK; } return cow_block(vmp, region, ph, 0); }
static int mappedfile_pagefault(struct vmproc *vmp, struct vir_region *region, struct phys_region *ph, int write, vfs_callback_t cb, void *state, int statelen, int *io) { u32_t allocflags; int procfd = region->param.file.fdref->fd; allocflags = vrallocflags(region->flags); assert(ph->ph->refcount > 0); assert(region->param.file.inited); assert(region->param.file.fdref); assert(region->param.file.fdref->dev != NO_DEV); /* Totally new block? Create it. */ if(ph->ph->phys == MAP_NONE) { struct cached_page *cp; u64_t referenced_offset = region->param.file.offset + ph->offset; if(region->param.file.fdref->ino == VMC_NO_INODE) { cp = find_cached_page_bydev(region->param.file.fdref->dev, referenced_offset, VMC_NO_INODE, 0, 1); } else { cp = find_cached_page_byino(region->param.file.fdref->dev, region->param.file.fdref->ino, referenced_offset, 1); } /* * Normally, a cache hit saves a round-trip to the file system * to load the page. However, if the page in the VM cache is * marked for one-time use, then force a round-trip through the * file system anyway, so that the FS can update the page by * by readding it to the cache. Thus, for one-time use pages, * no caching is performed. This approach is correct even in * the light of concurrent requests and disappearing processes * but relies on VM requests to VFS being fully serialized. */ if(cp && (!cb || !(cp->flags & VMSF_ONCE))) { int result = OK; pb_unreferenced(region, ph, 0); pb_link(ph, cp->page, ph->offset, region); if(roundup(ph->offset+region->param.file.clearend, VM_PAGE_SIZE) >= region->length) { result = cow_block(vmp, region, ph, region->param.file.clearend); } else if(result == OK && write) { result = cow_block(vmp, region, ph, 0); } /* Discard one-use pages after mapping them in. */ if (result == OK && (cp->flags & VMSF_ONCE)) rmcache(cp); return result; } if(!cb) { #if 0 printf("VM: mem_file: no callback, returning EFAULT\n"); sys_diagctl_stacktrace(vmp->vm_endpoint); #endif return EFAULT; } if(vfs_request(VMVFSREQ_FDIO, procfd, vmp, referenced_offset, VM_PAGE_SIZE, cb, NULL, state, statelen) != OK) { printf("VM: mappedfile_pagefault: vfs_request failed\n"); return ENOMEM; } *io = 1; return SUSPEND; } if(!write) { #if 0 printf("mappedfile_pagefault: nonwrite fault?\n"); #endif return OK; } return cow_block(vmp, region, ph, 0); }