#define MMAP_LOTSAMISS (100)
/**
- * filemap_nopage - read in file data for page fault handling
- * @area: the applicable vm_area
- * @address: target address to read in
- * @type: returned with VM_FAULT_{MINOR,MAJOR} if not %NULL
+ * filemap_fault - read in file data for page fault handling
+ * @vma: user vma (not used)
+ * @fdata: the applicable fault_data
*
- * filemap_nopage() is invoked via the vma operations vector for a
+ * filemap_fault() is invoked via the vma operations vector for a
* mapped memory region to read in file data during a page fault.
*
* The goto's are kind of ugly, but this streamlines the normal case of having
* it in the page cache, and handles the special cases reasonably without
* having a lot of duplicated code.
*/
-struct page *filemap_nopage(struct vm_area_struct *area,
- unsigned long address, int *type)
+struct page *filemap_fault(struct vm_area_struct *vma, struct fault_data *fdata)
{
int error;
- struct file *file = area->vm_file;
+ struct file *file = vma->vm_file;
struct address_space *mapping = file->f_mapping;
struct file_ra_state *ra = &file->f_ra;
struct inode *inode = mapping->host;
struct page *page;
- unsigned long size, pgoff;
- int did_readaround = 0, majmin = VM_FAULT_MINOR;
+ unsigned long size;
+ int did_readaround = 0;
- BUG_ON(!(area->vm_flags & VM_CAN_INVALIDATE));
+ fdata->type = VM_FAULT_MINOR;
- pgoff = ((address-area->vm_start) >> PAGE_CACHE_SHIFT) + area->vm_pgoff;
+ BUG_ON(!(vma->vm_flags & VM_CAN_INVALIDATE));
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (pgoff >= size)
+ if (fdata->pgoff >= size)
goto outside_data_content;
/* If we don't want any read-ahead, don't bother */
- if (VM_RandomReadHint(area))
+ if (VM_RandomReadHint(vma))
goto no_cached_page;
/*
*
* For sequential accesses, we use the generic readahead logic.
*/
- if (VM_SequentialReadHint(area))
- page_cache_readahead(mapping, ra, file, pgoff, 1);
+ if (VM_SequentialReadHint(vma))
+ page_cache_readahead(mapping, ra, file, fdata->pgoff, 1);
/*
* Do we have something in the page cache already?
*/
retry_find:
- page = find_lock_page(mapping, pgoff);
+ page = find_lock_page(mapping, fdata->pgoff);
if (!page) {
unsigned long ra_pages;
- if (VM_SequentialReadHint(area)) {
- handle_ra_miss(mapping, ra, pgoff);
+ if (VM_SequentialReadHint(vma)) {
+ handle_ra_miss(mapping, ra, fdata->pgoff);
goto no_cached_page;
}
ra->mmap_miss++;
* check did_readaround, as this is an inner loop.
*/
if (!did_readaround) {
- majmin = VM_FAULT_MAJOR;
+ fdata->type = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
}
did_readaround = 1;
if (ra_pages) {
pgoff_t start = 0;
- if (pgoff > ra_pages / 2)
- start = pgoff - ra_pages / 2;
+ if (fdata->pgoff > ra_pages / 2)
+ start = fdata->pgoff - ra_pages / 2;
do_page_cache_readahead(mapping, file, start, ra_pages);
}
- page = find_lock_page(mapping, pgoff);
+ page = find_lock_page(mapping, fdata->pgoff);
if (!page)
goto no_cached_page;
}
/* Must recheck i_size under page lock */
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (unlikely(pgoff >= size)) {
+ if (unlikely(fdata->pgoff >= size)) {
unlock_page(page);
goto outside_data_content;
}
* Found the page and have a reference on it.
*/
mark_page_accessed(page);
- if (type)
- *type = majmin;
return page;
outside_data_content:
* An external ptracer can access pages that normally aren't
* accessible..
*/
- if (area->vm_mm == current->mm)
- return NOPAGE_SIGBUS;
+ if (vma->vm_mm == current->mm) {
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
+ }
/* Fall through to the non-read-ahead case */
no_cached_page:
/*
* We're only likely to ever get here if MADV_RANDOM is in
* effect.
*/
- error = page_cache_read(file, pgoff);
+ error = page_cache_read(file, fdata->pgoff);
/*
* The page we want has now been added to the page cache.
* to schedule I/O.
*/
if (error == -ENOMEM)
- return NOPAGE_OOM;
- return NOPAGE_SIGBUS;
+ fdata->type = VM_FAULT_OOM;
+ else
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
page_not_uptodate:
/* IO error path */
if (!did_readaround) {
- majmin = VM_FAULT_MAJOR;
+ fdata->type = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
}
/* Things didn't work out. Return zero to tell the mm layer so. */
shrink_readahead_size_eio(file, ra);
- return NOPAGE_SIGBUS;
+ fdata->type = VM_FAULT_SIGBUS;
+ return NULL;
+}
+EXPORT_SYMBOL(filemap_fault);
+
+/*
+ * filemap_nopage and filemap_populate are legacy exports that are not used
+ * in tree. Scheduled for removal.
+ */
+struct page *filemap_nopage(struct vm_area_struct *area,
+ unsigned long address, int *type)
+{
+ struct page *page;
+ struct fault_data fdata;
+ fdata.address = address;
+ fdata.pgoff = ((address - area->vm_start) >> PAGE_CACHE_SHIFT)
+ + area->vm_pgoff;
+ fdata.flags = 0;
+
+ page = filemap_fault(area, &fdata);
+ if (type)
+ *type = fdata.type;
+
+ return page;
}
EXPORT_SYMBOL(filemap_nopage);
EXPORT_SYMBOL(filemap_populate);
struct vm_operations_struct generic_file_vm_ops = {
- .nopage = filemap_nopage,
- .populate = filemap_populate,
+ .fault = filemap_fault,
};
/* This is used for a general mmap of a disk file */
return -ENOEXEC;
file_accessed(file);
vma->vm_ops = &generic_file_vm_ops;
- vma->vm_flags |= VM_CAN_INVALIDATE;
+ vma->vm_flags |= VM_CAN_INVALIDATE | VM_CAN_NONLINEAR;
return 0;
}
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff