---------------------------
-What: vm_ops.nopage
-When: Soon, provided in-kernel callers have been converted
-Why: This interface is replaced by vm_ops.fault, but it has been around
- forever, is used by a lot of drivers, and doesn't cost much to
- maintain.
-Who: Nick Piggin <npiggin@suse.de>
-
----------------------------
-
What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
When: October 2008
Why: The stacking of class devices makes these values misleading and
void (*open)(struct vm_area_struct*);
void (*close)(struct vm_area_struct*);
int (*fault)(struct vm_area_struct*, struct vm_fault *);
- struct page *(*nopage)(struct vm_area_struct*, unsigned long, int *);
int (*page_mkwrite)(struct vm_area_struct *, struct page *);
locking rules:
open: no yes
close: no yes
fault: no yes
-nopage: no yes
page_mkwrite: no yes no
->page_mkwrite() is called when a previously read-only page is
ipc/shm.c::shm_delete() - may need BKL.
->read() and ->write() in many drivers are (probably) missing BKL.
-drivers/sgi/char/graphics.c::sgi_graphics_nopage() - may need BKL.
/*
* TODO:
* - remove "mark pages reserved-hacks" from memory allocation code
- * and implement nopage()
+ * and implement fault()
* - check decimation, calculating and reporting image size when
* using decimation
* - implement read(), user mode buffers and overlay (?)
/*
* It seems like __get_free_pages only ups the usage count
- * of the first page. This doesn't work with nopage mapping, so
- * up the usage count once more.
+ * of the first page. This doesn't work with fault mapping, so
+ * up the usage count once more (XXX: should use split_page or
+ * compound page).
*/
memset((void *)va->logical, 0x00, va->size);
int error;
/*
- * Due to the order of unstuffing files and ->nopage(), we can be
+ * Due to the order of unstuffing files and ->fault(), we can be
* asked for a zero page in the case of a stuffed file being extended,
* so we need to supply one here. It doesn't happen often.
*/
void (*open)(struct vm_area_struct * area);
void (*close)(struct vm_area_struct * area);
int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
- struct page *(*nopage)(struct vm_area_struct *area,
- unsigned long address, int *type);
unsigned long (*nopfn)(struct vm_area_struct *area,
unsigned long address);
return atomic_read(&(page)->_mapcount) >= 0;
}
-/*
- * Error return values for the *_nopage functions
- */
-#define NOPAGE_SIGBUS (NULL)
-#define NOPAGE_OOM ((struct page *) (-1))
-
/*
* Error return values for the *_nopfn functions
*/
if (pages)
foll_flags |= FOLL_GET;
if (!write && !(vma->vm_flags & VM_LOCKED) &&
- (!vma->vm_ops || (!vma->vm_ops->nopage &&
- !vma->vm_ops->fault)))
+ (!vma->vm_ops || !vma->vm_ops->fault))
foll_flags |= FOLL_ANON;
do {
BUG_ON(vma->vm_flags & VM_PFNMAP);
- if (likely(vma->vm_ops->fault)) {
- ret = vma->vm_ops->fault(vma, &vmf);
- if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
- return ret;
- } else {
- /* Legacy ->nopage path */
- ret = 0;
- vmf.page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
- /* no page was available -- either SIGBUS or OOM */
- if (unlikely(vmf.page == NOPAGE_SIGBUS))
- return VM_FAULT_SIGBUS;
- else if (unlikely(vmf.page == NOPAGE_OOM))
- return VM_FAULT_OOM;
- }
+ ret = vma->vm_ops->fault(vma, &vmf);
+ if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
+ return ret;
/*
* For consistency in subsequent calls, make the faulted page always
if (!pte_present(entry)) {
if (pte_none(entry)) {
if (vma->vm_ops) {
- if (vma->vm_ops->fault || vma->vm_ops->nopage)
+ if (likely(vma->vm_ops->fault))
return do_linear_fault(mm, vma, address,
pte, pmd, write_access, entry);
if (unlikely(vma->vm_ops->nopfn))
* When tmpfs swaps out a page from a file, any process mapping that
* file will not get a swp_entry_t in its pte, but rather it is like
* any other file mapping (ie. marked !present and faulted in with
- * tmpfs's .nopage). So swapped out tmpfs mappings are tested here.
+ * tmpfs's .fault). So swapped out tmpfs mappings are tested here.
*
* However when tmpfs moves the page from pagecache and into swapcache,
* it is still in core, but the find_get_page below won't find it.
printk (KERN_EMERG " page->mapping = %p\n", page->mapping);
print_symbol (KERN_EMERG " vma->vm_ops = %s\n", (unsigned long)vma->vm_ops);
if (vma->vm_ops) {
- print_symbol (KERN_EMERG " vma->vm_ops->nopage = %s\n", (unsigned long)vma->vm_ops->nopage);
print_symbol (KERN_EMERG " vma->vm_ops->fault = %s\n", (unsigned long)vma->vm_ops->fault);
}
if (vma->vm_file && vma->vm_file->f_op)