/**
* page_remove_pte - free an Page sturct which is related linear address la
* - and clean(invalidate) pte which is related linear address la
* @param pgdir page directory (not used)
* @param la logical address of the page to be removed
* @param page table entry of the page to be removed
* note: PT is changed, so the TLB need to be invalidate
*/
void
page_remove_pte(pgd_t *pgdir, uintptr_t la, pte_t *ptep) {
if (ptep_present(ptep)) {
struct Page *page = pte2page(*ptep);
if (!PageSwap(page)) {
if (page_ref_dec(page) == 0) {
//Don't free dma pages
if (!PageIO(page))
free_page(page);
}
}
else {
if (ptep_dirty(ptep)) {
SetPageDirty(page);
}
page_ref_dec(page);
}
ptep_unmap(ptep);
mp_tlb_invalidate(pgdir, la);
}
else if (! ptep_invalid(ptep)) {
#ifndef CONFIG_NO_SWAP
swap_remove_entry(*ptep);
#endif
ptep_unmap(ptep);
}
}
/**
* crystalhd_unmap_sgl - Release mapped resources
* @adp: Adapter instance
* @dio: DIO request instance
*
* Return:
* Status.
*
* This routine is to unmap the user buffer pages.
*/
BC_STATUS crystalhd_unmap_dio(struct crystalhd_adp *adp, struct crystalhd_dio_req *dio)
{
struct page *page = NULL;
int j = 0;
if (!adp || !dio) {
printk(KERN_ERR "%s: Invalid arg\n", __func__);
return BC_STS_INV_ARG;
}
if ((dio->page_cnt > 0) && (dio->sig != crystalhd_dio_inv)) {
for (j = 0; j < dio->page_cnt; j++) {
page = dio->pages[j];
if (page) {
if (!PageReserved(page) &&
(dio->direction == DMA_FROM_DEVICE))
SetPageDirty(page);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0)
put_page(page);
#else
page_cache_release(page);
#endif
}
}
}
if (dio->sig == crystalhd_dio_sg_mapped)
pci_unmap_sg(adp->pdev, dio->sg, dio->page_cnt, dio->direction);
crystalhd_free_dio(adp, dio);
return BC_STS_SUCCESS;
}
int add_to_swap(struct page *page)
{
swp_entry_t entry;
int err;
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(!PageUptodate(page));
entry = get_swap_page();
if (!entry.val)
return 0;
if (unlikely(PageTransHuge(page)))
if (unlikely(split_huge_page(page))) {
swapcache_free(entry, NULL);
return 0;
}
err = add_to_swap_cache(page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
if (!err) {
SetPageDirty(page);
return 1;
} else {
swapcache_free(entry, NULL);
return 0;
}
}
// swap_out_vma - try unmap pte & move pages into swap active list.
static int
swap_out_vma(struct mm_struct *mm, struct vma_struct *vma, uintptr_t addr, size_t require) {
if (require == 0 || !(addr >= vma->vm_start && addr < vma->vm_end)) {
return 0;
}
uintptr_t end;
size_t free_count = 0;
addr = ROUNDDOWN(addr, PGSIZE), end = ROUNDUP(vma->vm_end, PGSIZE);
while (addr < end && require != 0) {
pte_t *ptep = get_pte(mm->pgdir, addr, 0);
if (ptep == NULL) {
if (get_pud(mm->pgdir, addr, 0) == NULL) {
addr = ROUNDDOWN(addr + PUSIZE, PUSIZE);
}
else if (get_pmd(mm->pgdir, addr, 0) == NULL) {
addr = ROUNDDOWN(addr + PMSIZE, PMSIZE);
}
else {
addr = ROUNDDOWN(addr + PTSIZE, PTSIZE);
}
continue ;
}
if (ptep_present(ptep)) {
struct Page *page = pte2page(*ptep);
assert(!PageReserved(page));
if (ptep_accessed(ptep)) {
ptep_unset_accessed(ptep);
mp_tlb_invalidate(mm->pgdir, addr);
goto try_next_entry;
}
if (!PageSwap(page)) {
if (!swap_page_add(page, 0)) {
goto try_next_entry;
}
swap_active_list_add(page);
}
else if (ptep_dirty(ptep)) {
SetPageDirty(page);
}
swap_entry_t entry = page->index;
swap_duplicate(entry);
page_ref_dec(page);
ptep_copy(ptep, &entry);
mp_tlb_invalidate(mm->pgdir, addr);
mm->swap_address = addr + PGSIZE;
free_count ++, require --;
if ((vma->vm_flags & VM_SHARE) && page_ref(page) == 1) {
uintptr_t shmem_addr = addr - vma->vm_start + vma->shmem_off;
pte_t *sh_ptep = shmem_get_entry(vma->shmem, shmem_addr, 0);
assert(sh_ptep != NULL && ! ptep_invalid(sh_ptep));
if (ptep_present(sh_ptep)) {
shmem_insert_entry(vma->shmem, shmem_addr, entry);
}
}
}
try_next_entry:
addr += PGSIZE;
}
return free_count;
}
static void
via_free_sg_info(struct pci_dev *pdev, drm_via_sg_info_t *vsg)
{
struct page *page;
int i;
switch(vsg->state) {
case dr_via_device_mapped:
via_unmap_blit_from_device(pdev, vsg);
case dr_via_desc_pages_alloc:
for (i=0; i<vsg->num_desc_pages; ++i) {
if (vsg->desc_pages[i] != NULL)
free_page((unsigned long)vsg->desc_pages[i]);
}
kfree(vsg->desc_pages);
case dr_via_pages_locked:
for (i=0; i<vsg->num_pages; ++i) {
if ( NULL != (page = vsg->pages[i])) {
if (! PageReserved(page) && (DMA_FROM_DEVICE == vsg->direction))
SetPageDirty(page);
page_cache_release(page);
}
}
case dr_via_pages_alloc:
vfree(vsg->pages);
default:
vsg->state = dr_via_sg_init;
}
if (vsg->bounce_buffer) {
vfree(vsg->bounce_buffer);
vsg->bounce_buffer = NULL;
}
vsg->free_on_sequence = 0;
}
/*
* Free the swap entry like above, but also try to
* free the page cache entry if it is the last user.
*/
void free_swap_and_cache(swp_entry_t entry)
{
struct swap_info_struct * p;
struct page *page = NULL;
if (is_migration_entry(entry))
return;
p = swap_info_get(entry);
if (p) {
if (swap_entry_free(p, swp_offset(entry)) == 1) {
page = find_get_page(&swapper_space, entry.val);
if (page && unlikely(TestSetPageLocked(page))) {
page_cache_release(page);
page = NULL;
}
}
spin_unlock(&swap_lock);
}
if (page) {
int one_user;
BUG_ON(PagePrivate(page));
one_user = (page_count(page) == 2);
/* Only cache user (+us), or swap space full? Free it! */
/* Also recheck PageSwapCache after page is locked (above) */
if (PageSwapCache(page) && !PageWriteback(page) &&
(one_user || vm_swap_full())) {
delete_from_swap_cache(page);
SetPageDirty(page);
}
unlock_page(page);
page_cache_release(page);
}
}
static inline void shmem_remove_entry_pte(pte_t * ptep)
{
//TODO
//assert(0);
assert(ptep != NULL);
if (ptep_present(ptep)) {
struct Page *page = pte2page(*ptep);
#ifdef UCONFIG_SWAP
if (!PageSwap(page)) {
if (page_ref_dec(page) == 0) {
free_page(page);
}
} else {
if (ptep_dirty(ptep)) {
SetPageDirty(page);
}
page_ref_dec(page);
}
#else
if (page_ref_dec(page) == 0) {
free_page(page);
}
#endif /* UCONFIG_SWAP */
ptep_unmap(ptep);
} else if (!ptep_invalid(ptep)) {
#ifdef UCONFIG_SWAP
swap_remove_entry(*ptep);
ptep_unmap(ptep);
#else
assert(0);
#endif
}
}
static int mmap_mem(struct file *file, struct vm_area_struct *vma)
{
size_t size = vma->vm_end - vma->vm_start;
char *ptr_page;
int i;
struct page *mmap_page;
mmap_page = alloc_pages(GFP_KERNEL, get_order(size));
printk(KERN_NOTICE "mmap:pgoff=%x size=%d pfn=%x\n",
(int)vma->vm_pgoff, size, (int)page_to_pfn(mmap_page));
/* Remap-pfn-range will mark the range VM_IO */
if (remap_pfn_range(vma,
vma->vm_start,
page_to_pfn(mmap_page),
size,
vma->vm_page_prot)) {
return -EAGAIN;
}
ptr_page = kmap_atomic(mmap_page);
for (i = 0; i < 100; i++)
ptr_page[i] = (char)vma->vm_pgoff;
kunmap_atomic(ptr_page);
SetPageDirty(mmap_page); /* only the first page */
flush_dcache_page(mmap_page);
vma->vm_ops = &my_mem_vm_ops;
vma->vm_ops->open(vma);
return 0;
}
static inline void pages_dirty(void)
{
unsigned int i;
/* set the pages as dirty */
for (i = 0; i < nr_pages; i++)
SetPageDirty(pages[i]);
}
void end_swap_bio_read(struct bio *bio, int err)
{
const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct page *page = bio->bi_io_vec[0].bv_page;
if (!uptodate) {
SetPageError(page);
ClearPageUptodate(page);
printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
imajor(bio->bi_bdev->bd_inode),
iminor(bio->bi_bdev->bd_inode),
(unsigned long long)bio->bi_sector);
goto out;
}
SetPageUptodate(page);
/*
* There is no guarantee that the page is in swap cache - the software
* suspend code (at least) uses end_swap_bio_read() against a non-
* swapcache page. So we must check PG_swapcache before proceeding with
* this optimization.
*/
if (likely(PageSwapCache(page))) {
/*
* The swap subsystem performs lazy swap slot freeing,
* expecting that the page will be swapped out again.
* So we can avoid an unnecessary write if the page
* isn't redirtied.
* This is good for real swap storage because we can
* reduce unnecessary I/O and enhance wear-leveling
* if an SSD is used as the as swap device.
* But if in-memory swap device (eg zram) is used,
* this causes a duplicated copy between uncompressed
* data in VM-owned memory and compressed data in
* zram-owned memory. So let's free zram-owned memory
* and make the VM-owned decompressed page *dirty*,
* so the page should be swapped out somewhere again if
* we again wish to reclaim it.
*/
struct gendisk *disk = bio->bi_bdev->bd_disk;
if (disk->fops->swap_slot_free_notify) {
swp_entry_t entry;
unsigned long offset;
entry.val = page_private(page);
offset = swp_offset(entry);
SetPageDirty(page);
disk->fops->swap_slot_free_notify(bio->bi_bdev,
offset);
}
}
out:
unlock_page(page);
bio_put(bio);
}
/*
* ->writepage to the blockdev's mapping has to redirty the page so that the
* VM doesn't go and steal it. We return AOP_WRITEPAGE_ACTIVATE so that the VM
* won't try to (pointlessly) write the page again for a while.
*
* Really, these pages should not be on the LRU at all.
*/
static int ramdisk_writepage(struct page *page, struct writeback_control *wbc)
{
if (!PageUptodate(page))
make_page_uptodate(page);
SetPageDirty(page);
if (wbc->for_reclaim)
return AOP_WRITEPAGE_ACTIVATE;
unlock_page(page);
return 0;
}
static inline void pages_unmap(void)
{
unsigned int i;
/* set the pages as dirty */
for (i = 0; i < nr_pages; i++) {
if (!PageReserved(pages[i]))
SetPageDirty(pages[i]);
put_page(pages[i]);
}
}
void unlock_pages(struct page **page_list)
{
if ( !page_list )
return;
while (*page_list) {
if (!PageReserved(*page_list))
SetPageDirty(*page_list);
put_page(*page_list);
page_list++;
}
}
static int ramdisk_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
{
if (!Page_Uptodate(page)) {
void *addr = page_address(page);
memset(addr, 0, PAGE_CACHE_SIZE);
flush_dcache_page(page);
SetPageUptodate(page);
}
SetPageDirty(page);
return 0;
}
void vfi_dealloc_pages(struct vfi_smb *smb)
{
while(smb->num_pages--) {
struct page *page = smb->pages[smb->num_pages];
if (smb->address) {
if (! PageReserved(page))
SetPageDirty(page);
page_cache_release(page);
}
else
__free_pages(smb->pages[smb->num_pages],0);
}
kfree(smb->pages);
}
/*
* Strange swizzling function only for use by shmem_writepage
*/
int move_to_swap_cache(struct page *page, swp_entry_t entry)
{
int err = __add_to_swap_cache(page, entry, GFP_ATOMIC);
if (!err) {
remove_from_page_cache(page);
page_cache_release(page); /* pagecache ref */
if (!swap_duplicate(entry))
BUG();
SetPageDirty(page);
INC_CACHE_INFO(add_total);
} else if (err == -EEXIST)
INC_CACHE_INFO(exist_race);
return err;
}
/*
* Try to make the page cache and handle ready for the inline data case.
* We can call this function in 2 cases:
* 1. The inode is created and the first write exceeds inline size. We can
* clear the inode state safely.
* 2. The inode has inline data, then we need to read the data, make it
* update and dirty so that ext4_da_writepages can handle it. We don't
* need to start the journal since the file's metatdata isn't changed now.
*/
static int ext4_da_convert_inline_data_to_extent(struct address_space *mapping,
struct inode *inode,
unsigned flags,
void **fsdata)
{
int ret = 0, inline_size;
struct page *page;
page = grab_cache_page_write_begin(mapping, 0, flags);
if (!page)
return -ENOMEM;
down_read(&EXT4_I(inode)->xattr_sem);
if (!ext4_has_inline_data(inode)) {
ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
goto out;
}
inline_size = ext4_get_inline_size(inode);
if (!PageUptodate(page)) {
ret = ext4_read_inline_page(inode, page);
if (ret < 0)
goto out;
}
ret = __block_write_begin(page, 0, inline_size,
ext4_da_get_block_prep);
if (ret) {
up_read(&EXT4_I(inode)->xattr_sem);
unlock_page(page);
page_cache_release(page);
ext4_truncate_failed_write(inode);
return ret;
}
SetPageDirty(page);
SetPageUptodate(page);
ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
*fsdata = (void *)CONVERT_INLINE_DATA;
out:
up_read(&EXT4_I(inode)->xattr_sem);
if (page) {
unlock_page(page);
page_cache_release(page);
}
return ret;
}
/**
* add_to_swap - allocate swap space for a page
* @page: page we want to move to swap
*
* Allocate swap space for the page and add the page to the
* swap cache. Caller needs to hold the page lock.
*/
int add_to_swap(struct page *page)
{
swp_entry_t entry;
int err;
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(!PageUptodate(page));
#ifdef CONFIG_HSWAP
if (!current_is_kswapd())
entry = get_lowest_prio_swap_page();
else
#endif
entry = get_swap_page();
if (!entry.val)
return 0;
if (unlikely(PageTransHuge(page)))
if (unlikely(split_huge_page(page))) {
swapcache_free(entry, NULL);
return 0;
}
/*
* Radix-tree node allocations from PF_MEMALLOC contexts could
* completely exhaust the page allocator. __GFP_NOMEMALLOC
* stops emergency reserves from being allocated.
*
* TODO: this could cause a theoretical memory reclaim
* deadlock in the swap out path.
*/
/*
* Add it to the swap cache and mark it dirty
*/
err = add_to_swap_cache(page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
if (!err) { /* Success */
SetPageDirty(page);
return 1;
} else { /* -ENOMEM radix-tree allocation failure */
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
* clear SWAP_HAS_CACHE flag.
*/
swapcache_free(entry, NULL);
return 0;
}
}
// swap_page_add - set PG_swap flag in page, set page->index = entry, and add page to hash_list.
// - if entry==0, It means ???
static bool
swap_page_add(struct Page *page, swap_entry_t entry) {
assert(!PageSwap(page));
if (entry == 0) {
if ((entry = try_alloc_swap_entry()) == 0) {
return 0;
}
assert(mem_map[swap_offset(entry)] == SWAP_UNUSED);
mem_map[swap_offset(entry)] = 0;
SetPageDirty(page);
}
SetPageSwap(page);
page->index = entry;
list_add(hash_list + entry_hashfn(entry), &(page->page_link));
return 1;
}
int
mic_unpin_user_pages(struct page **pages, uint32_t nf_pages)
{
uint32_t j = 0;
uint32_t status = 0;
if (pages) {
for (j = 0; j < nf_pages; j++) {
if (pages[j]) {
SetPageDirty(pages[j]);
page_cache_release(pages[j]);
}
}
kfree(pages);
}
return status;
}
void release_user_pages(struct csession *ses)
{
unsigned int i;
for (i = 0; i < ses->used_pages; i++) {
if (!PageReserved(ses->pages[i]))
SetPageDirty(ses->pages[i]);
if (ses->readonly_pages == 0)
flush_dcache_page(ses->pages[i]);
else
ses->readonly_pages--;
page_cache_release(ses->pages[i]);
}
ses->used_pages = 0;
}
/**
* add_to_swap - allocate swap space for a page
* @page: page we want to move to swap
*
* Allocate swap space for the page and add the page to the
* swap cache. Caller needs to hold the page lock.
*/
int add_to_swap(struct page *page)
{
swp_entry_t entry;
int err;
struct user_beancounter *ub;
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(!PageUptodate(page));
ub = pb_grab_page_ub(page);
if (IS_ERR(ub))
return 0;
entry = get_swap_page(ub);
put_beancounter(ub);
if (!entry.val)
return 0;
/*
* Radix-tree node allocations from PF_MEMALLOC contexts could
* completely exhaust the page allocator. __GFP_NOMEMALLOC
* stops emergency reserves from being allocated.
*
* TODO: this could cause a theoretical memory reclaim
* deadlock in the swap out path.
*/
/*
* Add it to the swap cache and mark it dirty
*/
err = add_to_swap_cache(page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
if (!err) { /* Success */
SetPageDirty(page);
return 1;
} else { /* -ENOMEM radix-tree allocation failure */
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
* clear SWAP_HAS_CACHE flag.
*/
swapcache_free(entry, NULL);
return 0;
}
}
/**
* add_to_swap - allocate swap space for a page
* @page: page we want to move to swap
*
* Allocate swap space for the page and add the page to the
* swap cache. Caller needs to hold the page lock.
*/
int add_to_swap(struct page * page, gfp_t gfp_mask)
{
swp_entry_t entry;
int err;
if (!PageLocked(page))
BUG();
for (;;) {
entry = get_swap_page();
if (!entry.val)
return 0;
/*
* Radix-tree node allocations from PF_MEMALLOC contexts could
* completely exhaust the page allocator. __GFP_NOMEMALLOC
* stops emergency reserves from being allocated.
*
* TODO: this could cause a theoretical memory reclaim
* deadlock in the swap out path.
*/
/*
* Add it to the swap cache and mark it dirty
*/
err = __add_to_swap_cache(page, entry,
gfp_mask|__GFP_NOMEMALLOC|__GFP_NOWARN);
switch (err) {
case 0: /* Success */
SetPageUptodate(page);
SetPageDirty(page);
INC_CACHE_INFO(add_total);
return 1;
case -EEXIST:
/* Raced with "speculative" read_swap_cache_async */
INC_CACHE_INFO(exist_race);
swap_free(entry);
continue;
default:
/* -ENOMEM radix-tree allocation failure */
swap_free(entry);
return 0;
}
}
}
/**
* sgl_unmap_user_pages() - Release the scatter gather list pages
* @sgl: The scatter gather list
* @nr_pages: Number of pages in the list
* @dirty: Flag indicating whether the pages should be marked dirty
* @to_user: 1 when transfer is to/from user-space (0 for to/from kernel)
*
*/
static void sgl_unmap_user_pages(struct scatterlist *sgl,
const unsigned int nr_pages, int dirty,
int to_user)
{
int i;
if (!to_user)
return;
for (i = 0; i < nr_pages; i++) {
struct page *page = sg_page(&sgl[i]);
if (dirty && !PageReserved(page))
SetPageDirty(page);
page_cache_release (page);
}
}
static int pixel_data(struct ioctl_struct *ctrl, struct device_extension *pdx)
{
int i;
if (!pdx->gotPixelData)
return 0;
pdx->gotPixelData = 0;
ctrl->numbytes = pdx->bulk_in_size_returned;
pdx->bulk_in_size_returned -= pdx->frameSize;
for (i = 0; i < pdx->maplist_numPagesMapped[pdx->active_frame]; i++)
SetPageDirty(sg_page(&pdx->sgl[pdx->active_frame][i]));
pdx->active_frame = ((pdx->active_frame + 1) % pdx->num_frames);
return ctrl->numbytes;
}
void CGsCachedArea::Invalidate(uint32 memoryStart, uint32 memorySize)
{
uint32 areaSize = GetSize();
if(DoMemoryRangesOverlap(memoryStart, memorySize, m_bufPtr, areaSize))
{
//Find the pages that are touched by this transfer
uint32 pageStart = (memoryStart < m_bufPtr) ? 0 : ((memoryStart - m_bufPtr) / CGsPixelFormats::PAGESIZE);
uint32 pageCount = std::min<uint32>(GetPageCount(), (memorySize + CGsPixelFormats::PAGESIZE - 1) / CGsPixelFormats::PAGESIZE);
for(unsigned int i = 0; i < pageCount; i++)
{
SetPageDirty(pageStart + i);
}
//Wouldn't make sense to go through here and not have at least a dirty page
assert(HasDirtyPages());
}
}
/*
* Work out if there are any other processes sharing this
* swap cache page. Free it if you can. Return success.
*/
int remove_exclusive_swap_page(struct page *page)
{
int retval;
struct swap_info_struct * p;
swp_entry_t entry;
BUG_ON(PagePrivate(page));
BUG_ON(!PageLocked(page));
if (!PageSwapCache(page))
return 0;
if (PageWriteback(page))
return 0;
if (page_count(page) != 2) /* 2: us + cache */
return 0;
entry.val = page_private(page);
p = swap_info_get(entry);
if (!p)
return 0;
/* Is the only swap cache user the cache itself? */
retval = 0;
if (p->swap_map[swp_offset(entry)] == 1) {
/* Recheck the page count with the swapcache lock held.. */
write_lock_irq(&swapper_space.tree_lock);
if ((page_count(page) == 2) && !PageWriteback(page)) {
__delete_from_swap_cache(page);
SetPageDirty(page);
retval = 1;
}
write_unlock_irq(&swapper_space.tree_lock);
}
spin_unlock(&swap_lock);
if (retval) {
swap_free(entry);
page_cache_release(page);
}
return retval;
}
int simple_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
size_t size = vma->vm_end - vma->vm_start;
int i;
int ret;
struct page *map_page;
char *ptr;
printk(KERN_NOTICE "vmf:fault=%p flag=%x offset=%lx\n",
vmf->virtual_address,
vmf->flags,
vmf->pgoff);
printk(KERN_NOTICE "vma:start=0x%lx size=%x pgoff=%lx\n",
vma->vm_start,
(int)size,
vma->vm_pgoff);
vma->vm_flags |= VM_MIXEDMAP;
map_page = data_pages[vmf->pgoff];
ret = vm_insert_mixed(vma,
(unsigned long)vmf->virtual_address,
page_to_pfn(map_page));
printk(KERN_NOTICE "ret=%d pfn=%x vaddr=0x%lx cnt=%d\n",
ret,
(int)page_to_pfn(map_page),
(unsigned long)vmf->virtual_address,
page_count(map_page));
/*
* Example of the "Direct I/O"
*/
ptr = kmap_atomic(map_page);
for (i = 0; i < 100; i++) {
ptr[i] = (unsigned char)vmf->pgoff;
}
kunmap_atomic(ptr);
SetPageDirty(map_page);
return VM_FAULT_NOPAGE;
}
/*
* "Get" data from frontswap associated with swaptype and offset that were
* specified when the data was put to frontswap and use it to fill the
* specified page with data. Page must be locked and in the swap cache.
*/
int __frontswap_load(struct page *page)
{
int ret = -1;
swp_entry_t entry = { .val = page_private(page), };
int type = swp_type(entry);
struct swap_info_struct *sis = swap_info[type];
pgoff_t offset = swp_offset(entry);
BUG_ON(!PageLocked(page));
BUG_ON(sis == NULL);
if (frontswap_test(sis, offset))
ret = frontswap_ops.load(type, offset, page);
if (ret == 0) {
inc_frontswap_loads();
if (frontswap_tmem_exclusive_gets_enabled) {
SetPageDirty(page);
frontswap_clear(sis, offset);
}
}
return ret;
}
/*
* Work out if there are any other processes sharing this
* swap cache page. Free it if you can. Return success.
*/
int remove_exclusive_swap_page(struct page *page)
{
int retval;
struct swap_info_struct * p;
swp_entry_t entry;
if (!PageLocked(page))
BUG();
if (!PageSwapCache(page))
return 0;
if (page_count(page) - !!page->buffers != 2) /* 2: us + cache */
return 0;
entry.val = page->index;
p = swap_info_get(entry);
if (!p)
return 0;
/* Is the only swap cache user the cache itself? */
retval = 0;
if (p->swap_map[SWP_OFFSET(entry)] == 1) {
/* Recheck the page count with the pagecache lock held.. */
spin_lock(&pagecache_lock);
if (page_count(page) - !!page->buffers == 2) {
__delete_from_swap_cache(page);
SetPageDirty(page);
retval = 1;
}
spin_unlock(&pagecache_lock);
}
swap_info_put(p);
if (retval) {
block_flushpage(page, 0);
swap_free(entry);
page_cache_release(page);
}
return retval;
}