#include <linux/pagemap.h>
#include <linux/rmap.h>
#include <linux/module.h>
+#include <linux/delayacct.h>
#include <linux/init.h>
+#include <linux/writeback.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
return retval;
}
-/*
+/**
+ * vm_insert_page - insert single page into user vma
+ * @vma: user vma to map to
+ * @addr: target user address of this page
+ * @page: source kernel page
+ *
* This allows drivers to insert individual pages they've allocated
* into a user vma.
*
return 0;
}
-/* Note: this is only safe if the mm semaphore is held when called. */
+/**
+ * remap_pfn_range - remap kernel memory to userspace
+ * @vma: user vma to map to
+ * @addr: target user address to start at
+ * @pfn: physical address of kernel memory
+ * @size: size of map area
+ * @prot: page protection flags for this mapping
+ *
+ * Note: this is only safe if the mm semaphore is held when called.
+ */
int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn, unsigned long size, pgprot_t prot)
{
{
struct page *old_page, *new_page;
pte_t entry;
- int reuse, ret = VM_FAULT_MINOR;
+ int reuse = 0, ret = VM_FAULT_MINOR;
+ struct page *dirty_page = NULL;
old_page = vm_normal_page(vma, address, orig_pte);
if (!old_page)
goto gotten;
- if (unlikely((vma->vm_flags & (VM_SHARED|VM_WRITE)) ==
- (VM_SHARED|VM_WRITE))) {
+ /*
+ * Take out anonymous pages first, anonymous shared vmas are
+ * not dirty accountable.
+ */
+ if (PageAnon(old_page)) {
+ if (!TestSetPageLocked(old_page)) {
+ reuse = can_share_swap_page(old_page);
+ unlock_page(old_page);
+ }
+ } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
+ (VM_WRITE|VM_SHARED))) {
+ /*
+ * Only catch write-faults on shared writable pages,
+ * read-only shared pages can get COWed by
+ * get_user_pages(.write=1, .force=1).
+ */
if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
/*
* Notify the address space that the page is about to
if (!pte_same(*page_table, orig_pte))
goto unlock;
}
-
+ dirty_page = old_page;
+ get_page(dirty_page);
reuse = 1;
- } else if (PageAnon(old_page) && !TestSetPageLocked(old_page)) {
- reuse = can_share_swap_page(old_page);
- unlock_page(old_page);
- } else {
- reuse = 0;
}
if (reuse) {
flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ lazy_mmu_prot_update(entry);
ptep_establish(vma, address, page_table, entry);
update_mmu_cache(vma, address, entry);
- lazy_mmu_prot_update(entry);
lru_cache_add_active(new_page);
page_add_new_anon_rmap(new_page, vma, address);
page_cache_release(old_page);
unlock:
pte_unmap_unlock(page_table, ptl);
+ if (dirty_page) {
+ set_page_dirty_balance(dirty_page);
+ put_page(dirty_page);
+ }
return ret;
oom:
if (old_page)
}
EXPORT_SYMBOL(unmap_mapping_range);
-/*
- * Handle all mappings that got truncated by a "truncate()"
- * system call.
+/**
+ * vmtruncate - unmap mappings "freed" by truncate() syscall
+ * @inode: inode of the file used
+ * @offset: file offset to start truncating
*
* NOTE! We have to be ready to update the memory sharing
* between the file and the memory map for a potential last
return 0;
}
-EXPORT_SYMBOL(vmtruncate_range);
+EXPORT_UNUSED_SYMBOL(vmtruncate_range); /* June 2006 */
-/*
+/**
+ * swapin_readahead - swap in pages in hope we need them soon
+ * @entry: swap entry of this memory
+ * @addr: address to start
+ * @vma: user vma this addresses belong to
+ *
* Primitive swap readahead code. We simply read an aligned block of
* (1 << page_cluster) entries in the swap area. This method is chosen
* because it doesn't cost us any seek time. We also make sure to queue
- * the 'original' request together with the readahead ones...
+ * the 'original' request together with the readahead ones...
*
* This has been extended to use the NUMA policies from the mm triggering
* the readahead.
migration_entry_wait(mm, pmd, address);
goto out;
}
+ delayacct_set_flag(DELAYACCT_PF_SWAPIN);
page = lookup_swap_cache(entry);
if (!page) {
swapin_readahead(entry, address, vma);
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
if (likely(pte_same(*page_table, orig_pte)))
ret = VM_FAULT_OOM;
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
goto unlock;
}
grab_swap_token();
}
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
mark_page_accessed(page);
lock_page(page);
unsigned int sequence = 0;
int ret = VM_FAULT_MINOR;
int anon = 0;
+ struct page *dirty_page = NULL;
pte_unmap(page_table);
BUG_ON(vma->vm_flags & VM_PFNMAP);
} else {
inc_mm_counter(mm, file_rss);
page_add_file_rmap(new_page);
+ if (write_access) {
+ dirty_page = new_page;
+ get_page(dirty_page);
+ }
}
} else {
/* One of our sibling threads was faster, back out. */
lazy_mmu_prot_update(entry);
unlock:
pte_unmap_unlock(page_table, ptl);
+ if (dirty_page) {
+ set_page_dirty_balance(dirty_page);
+ put_page(dirty_page);
+ }
return ret;
oom:
page_cache_release(new_page);
projects / linux-2.6-omap-h63xx.git / blobdiff