/*
* This is for invalidate_inode_pages(). That function can be called at
* any time, and is not supposed to throw away dirty pages. But pages can
* be marked dirty at any time too. So we re-check the dirtiness inside
* ->tree_lock. That provides exclusion against the __set_page_dirty
* functions.
*/
static int
invalidate_complete_page(struct address_space *mapping, struct page *page)
{
if (page->mapping != mapping)
return 0;
if (PagePrivate(page) && !try_to_release_page(page, 0))
return 0;
spin_lock_irq(&mapping->tree_lock);
if (PageDirty(page)) {
spin_unlock_irq(&mapping->tree_lock);
return 0;
}
BUG_ON(PagePrivate(page));
if (page_count(page) != 2) {
spin_unlock_irq(&mapping->tree_lock);
return 0;
}
__remove_from_page_cache(page);
spin_unlock_irq(&mapping->tree_lock);
ClearPageUptodate(page);
page_cache_release(page); /* pagecache ref */
return 1;
}
/*
* Attempt to release the private state associated with a page
* - Called if either PG_private or PG_fscache is set on the page
* - Caller holds page lock
* - Return true (may release page) or false (may not)
*/
static int nfs_release_page(struct page *page, gfp_t gfp)
{
struct address_space *mapping = page->mapping;
dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
/* Always try to initiate a 'commit' if relevant, but only
* wait for it if __GFP_WAIT is set. Even then, only wait 1
* second and only if the 'bdi' is not congested.
* Waiting indefinitely can cause deadlocks when the NFS
* server is on this machine, when a new TCP connection is
* needed and in other rare cases. There is no particular
* need to wait extensively here. A short wait has the
* benefit that someone else can worry about the freezer.
*/
if (mapping) {
struct nfs_server *nfss = NFS_SERVER(mapping->host);
nfs_commit_inode(mapping->host, 0);
if ((gfp & __GFP_WAIT) &&
!bdi_write_congested(&nfss->backing_dev_info)) {
wait_on_page_bit_killable_timeout(page, PG_private,
HZ);
if (PagePrivate(page))
set_bdi_congested(&nfss->backing_dev_info,
BLK_RW_ASYNC);
}
}
/* If PagePrivate() is set, then the page is not freeable */
if (PagePrivate(page))
return 0;
return nfs_fscache_release_page(page, gfp);
}
static void *
bts_buffer_setup_aux(int cpu, void **pages, int nr_pages, bool overwrite)
{
struct bts_buffer *buf;
struct page *page;
int node = (cpu == -1) ? cpu : cpu_to_node(cpu);
unsigned long offset;
size_t size = nr_pages << PAGE_SHIFT;
int pg, nbuf, pad;
/* count all the high order buffers */
for (pg = 0, nbuf = 0; pg < nr_pages;) {
page = virt_to_page(pages[pg]);
if (WARN_ON_ONCE(!PagePrivate(page) && nr_pages > 1))
return NULL;
pg += 1 << page_private(page);
nbuf++;
}
/*
* to avoid interrupts in overwrite mode, only allow one physical
*/
if (overwrite && nbuf > 1)
return NULL;
buf = kzalloc_node(offsetof(struct bts_buffer, buf[nbuf]), GFP_KERNEL, node);
if (!buf)
return NULL;
buf->nr_pages = nr_pages;
buf->nr_bufs = nbuf;
buf->snapshot = overwrite;
buf->data_pages = pages;
buf->real_size = size - size % BTS_RECORD_SIZE;
for (pg = 0, nbuf = 0, offset = 0, pad = 0; nbuf < buf->nr_bufs; nbuf++) {
unsigned int __nr_pages;
page = virt_to_page(pages[pg]);
__nr_pages = PagePrivate(page) ? 1 << page_private(page) : 1;
buf->buf[nbuf].page = page;
buf->buf[nbuf].offset = offset;
buf->buf[nbuf].displacement = (pad ? BTS_RECORD_SIZE - pad : 0);
buf->buf[nbuf].size = buf_size(page) - buf->buf[nbuf].displacement;
pad = buf->buf[nbuf].size % BTS_RECORD_SIZE;
buf->buf[nbuf].size -= pad;
pg += __nr_pages;
offset += __nr_pages << PAGE_SHIFT;
}
return buf;
}
/*
* Try to drop buffers from the pages in a pagevec
*/
void pagevec_strip(struct pagevec *pvec)
{
int i;
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
if (PagePrivate(page) && trylock_page(page)) {
if (PagePrivate(page))
try_to_release_page(page, 0);
unlock_page(page);
}
}
}
static int v9fs_release_page(struct page *page, gfp_t gfp)
{
if (PagePrivate(page))
return 0;
return v9fs_fscache_release_page(page, gfp);
}
/*
* add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
* but sets SwapCache flag and private instead of mapping and index.
*/
int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
{
int error;
BUG_ON(!PageLocked(page));
BUG_ON(PageSwapCache(page));
BUG_ON(PagePrivate(page));
BUG_ON(!PageSwapBacked(page));
error = radix_tree_preload(gfp_mask);
if (!error) {
page_cache_get(page);
SetPageSwapCache(page);
set_page_private(page, entry.val);
spin_lock_irq(&swapper_space.tree_lock);
error = radix_tree_insert(&swapper_space.page_tree,
entry.val, page);
if (likely(!error)) {
total_swapcache_pages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
INC_CACHE_INFO(add_total);
}
spin_unlock_irq(&swapper_space.tree_lock);
radix_tree_preload_end();
if (unlikely(error)) {
set_page_private(page, 0UL);
ClearPageSwapCache(page);
page_cache_release(page);
}
}
return error;
}
/*
* Dirty a page. Optimistically adjust accounting, on the assumption
* that we won't race with invalidate. If we do, readjust.
*/
static int ceph_set_page_dirty(struct page *page)
{
struct address_space *mapping = page->mapping;
struct inode *inode;
struct ceph_inode_info *ci;
struct ceph_snap_context *snapc;
int ret;
if (unlikely(!mapping))
return !TestSetPageDirty(page);
if (PageDirty(page)) {
dout("%p set_page_dirty %p idx %lu -- already dirty\n",
mapping->host, page, page->index);
BUG_ON(!PagePrivate(page));
return 0;
}
inode = mapping->host;
ci = ceph_inode(inode);
/* dirty the head */
spin_lock(&ci->i_ceph_lock);
BUG_ON(ci->i_wr_ref == 0); // caller should hold Fw reference
if (__ceph_have_pending_cap_snap(ci)) {
struct ceph_cap_snap *capsnap =
list_last_entry(&ci->i_cap_snaps,
struct ceph_cap_snap,
ci_item);
snapc = ceph_get_snap_context(capsnap->context);
capsnap->dirty_pages++;
} else {
static int afs_releasepage(struct page *page, gfp_t gfp_flags)
{
struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
_enter("{{%x:%u}[%lu],%lx},%x",
vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
gfp_flags);
/* deny if page is being written to the cache and the caller hasn't
* elected to wait */
#ifdef CONFIG_AFS_FSCACHE
if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
_leave(" = F [cache busy]");
return 0;
}
#endif
if (PagePrivate(page)) {
if (wb) {
set_page_private(page, 0);
afs_put_writeback(wb);
}
ClearPagePrivate(page);
}
/* indicate that the page can be released */
_leave(" = T");
return 1;
}
/*
* Attempt to steal a page from a pipe buffer. This should perhaps go into
* a vm helper function, it's already simplified quite a bit by the
* addition of remove_mapping(). If success is returned, the caller may
* attempt to reuse this page for another destination.
*/
static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
struct page *page = buf->page;
struct address_space *mapping = page_mapping(page);
lock_page(page);
WARN_ON(!PageUptodate(page));
/*
* At least for ext2 with nobh option, we need to wait on writeback
* completing on this page, since we'll remove it from the pagecache.
* Otherwise truncate wont wait on the page, allowing the disk
* blocks to be reused by someone else before we actually wrote our
* data to them. fs corruption ensues.
*/
wait_on_page_writeback(page);
if (PagePrivate(page))
try_to_release_page(page, mapping_gfp_mask(mapping));
if (!remove_mapping(mapping, page)) {
unlock_page(page);
return 1;
}
buf->flags |= PIPE_BUF_FLAG_LRU;
return 0;
}
/*
* invalidate part or all of a page
*/
static void afs_file_invalidatepage(struct page *page, unsigned long offset)
{
int ret = 1;
_enter("{%lu},%lu", page->index, offset);
BUG_ON(!PageLocked(page));
if (PagePrivate(page)) {
#ifdef AFS_CACHING_SUPPORT
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
cachefs_uncache_page(vnode->cache,page);
#endif
/* We release buffers only if the entire page is being
* invalidated.
* The get_block cached value has been unconditionally
* invalidated, so real IO is not possible anymore.
*/
if (offset == 0) {
BUG_ON(!PageLocked(page));
ret = 0;
if (!PageWriteback(page))
ret = page->mapping->a_ops->releasepage(page,
0);
/* possibly should BUG_ON(!ret); - neilb */
}
}
_leave(" = %d", ret);
} /* end afs_file_invalidatepage() */
static void nfs_check_dirty_writeback(struct page *page,
bool *dirty, bool *writeback)
{
struct nfs_inode *nfsi;
struct address_space *mapping = page_file_mapping(page);
if (!mapping || PageSwapCache(page))
return;
/*
* Check if an unstable page is currently being committed and
* if so, have the VM treat it as if the page is under writeback
* so it will not block due to pages that will shortly be freeable.
*/
nfsi = NFS_I(mapping->host);
if (test_bit(NFS_INO_COMMIT, &nfsi->flags)) {
*writeback = true;
return;
}
/*
* If PagePrivate() is set, then the page is not freeable and as the
* inode is not being committed, it's not going to be cleaned in the
* near future so treat it as dirty
*/
if (PagePrivate(page))
*dirty = true;
}
/*
* __add_to_swap_cache resembles add_to_page_cache on swapper_space,
* but sets SwapCache flag and private instead of mapping and index.
*/
static int __add_to_swap_cache(struct page *page, swp_entry_t entry,
gfp_t gfp_mask)
{
int error;
BUG_ON(PageSwapCache(page));
BUG_ON(PagePrivate(page));
error = radix_tree_preload(gfp_mask);
if (!error) {
set_page_no_new_refs(page);
write_lock_irq(&swapper_space.tree_lock);
error = radix_tree_insert(&swapper_space.page_tree,
entry.val, page);
if (!error) {
page_cache_get(page);
SetPageLocked(page);
SetPageSwapCache(page);
set_page_private(page, entry.val);
total_swapcache_pages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
}
write_unlock_irq(&swapper_space.tree_lock);
end_page_no_new_refs(page);
radix_tree_preload_end();
}
return error;
}
/*
* invalidate part or all of a page
* - release a page and clean up its private data if offset is 0 (indicating
* the entire page)
*/
static void afs_invalidatepage(struct page *page, unsigned long offset)
{
struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
_enter("{%lu},%lu", page->index, offset);
BUG_ON(!PageLocked(page));
/* we clean up only if the entire page is being invalidated */
if (offset == 0) {
#ifdef CONFIG_AFS_FSCACHE
if (PageFsCache(page)) {
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
fscache_wait_on_page_write(vnode->cache, page);
fscache_uncache_page(vnode->cache, page);
ClearPageFsCache(page);
}
#endif
if (PagePrivate(page)) {
if (wb && !PageWriteback(page)) {
set_page_private(page, 0);
afs_put_writeback(wb);
}
if (!page_private(page))
ClearPagePrivate(page);
}
}
_leave("");
}
/**
* nfs_create_request - Create an NFS read/write request.
* @file: file descriptor to use
* @inode: inode to which the request is attached
* @page: page to write
* @offset: starting offset within the page for the write
* @count: number of bytes to read/write
*
* The page must be locked by the caller. This makes sure we never
* create two different requests for the same page.
* User should ensure it is safe to sleep in this function.
*/
struct nfs_page *
nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
struct page *page,
unsigned int offset, unsigned int count)
{
struct nfs_page *req;
/* try to allocate the request struct */
req = nfs_page_alloc();
if (req == NULL)
return ERR_PTR(-ENOMEM);
/* Initialize the request struct. Initially, we assume a
* long write-back delay. This will be adjusted in
* update_nfs_request below if the region is not locked. */
req->wb_page = page;
atomic_set(&req->wb_complete, 0);
req->wb_index = page->index;
page_cache_get(page);
BUG_ON(PagePrivate(page));
BUG_ON(!PageLocked(page));
BUG_ON(page->mapping->host != inode);
req->wb_offset = offset;
req->wb_pgbase = offset;
req->wb_bytes = count;
req->wb_context = get_nfs_open_context(ctx);
kref_init(&req->wb_kref);
return req;
}
/*
* For address_spaces which do not use buffers. Just tag the page as dirty in
* its radix tree.
*
* This is also used when a single buffer is being dirtied: we want to set the
* page dirty in that case, but not all the buffers. This is a "bottom-up"
* dirtying, whereas __set_page_dirty_buffers() is a "top-down" dirtying.
*
* Most callers have locked the page, which pins the address_space in memory.
* But zap_pte_range() does not lock the page, however in that case the
* mapping is pinned by the vma's ->vm_file reference.
*
* We take care to handle the case where the page was truncated from the
* mapping by re-checking page_mapping() inside tree_lock.
*/
int __set_page_dirty_nobuffers(struct page *page)
{
if (!TestSetPageDirty(page)) {
struct address_space *mapping = page_mapping(page);
struct address_space *mapping2;
if (!mapping)
return 1;
spin_lock_irq(&mapping->tree_lock);
mapping2 = page_mapping(page);
if (mapping2) { /* Race with truncate? */
BUG_ON(mapping2 != mapping);
WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
account_page_dirtied(page, mapping);
radix_tree_tag_set(&mapping->page_tree,
page_index(page), PAGECACHE_TAG_DIRTY);
}
spin_unlock_irq(&mapping->tree_lock);
if (mapping->host) {
/* !PageAnon && !swapper_space */
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
return 1;
}
return 0;
}
/*
* invalidate part or all of a page
*/
static void afs_invalidatepage(struct page *page, unsigned long offset)
{
int ret = 1;
_enter("{%lu},%lu", page->index, offset);
BUG_ON(!PageLocked(page));
if (PagePrivate(page)) {
/* We release buffers only if the entire page is being
* invalidated.
* The get_block cached value has been unconditionally
* invalidated, so real IO is not possible anymore.
*/
if (offset == 0) {
BUG_ON(!PageLocked(page));
ret = 0;
if (!PageWriteback(page))
ret = page->mapping->a_ops->releasepage(page,
0);
/* possibly should BUG_ON(!ret); - neilb */
}
}
_leave(" = %d", ret);
}
/*
* 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);
}
}
int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count)
{
int i, ret = 0;
bool lazy = false;
pte_t *pte;
if (xen_feature(XENFEAT_auto_translated_physmap))
return 0;
if (kmap_ops &&
!in_interrupt() &&
paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
arch_enter_lazy_mmu_mode();
lazy = true;
}
for (i = 0; i < count; i++) {
unsigned long mfn, pfn;
/* Do not add to override if the map failed. */
if (map_ops[i].status)
continue;
if (map_ops[i].flags & GNTMAP_contains_pte) {
pte = (pte_t *)(mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) +
(map_ops[i].host_addr & ~PAGE_MASK));
mfn = pte_mfn(*pte);
} else {
mfn = PFN_DOWN(map_ops[i].dev_bus_addr);
}
pfn = page_to_pfn(pages[i]);
WARN_ON(PagePrivate(pages[i]));
SetPagePrivate(pages[i]);
set_page_private(pages[i], mfn);
pages[i]->index = pfn_to_mfn(pfn);
if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
ret = -ENOMEM;
goto out;
}
if (kmap_ops) {
ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]);
if (ret)
goto out;
}
}
out:
if (lazy)
arch_leave_lazy_mmu_mode();
return ret;
}
/*
* Attempt to release the private state associated with a page
* - Called if either PG_private or PG_fscache is set on the page
* - Caller holds page lock
* - Return true (may release page) or false (may not)
*/
static int nfs_release_page(struct page *page, gfp_t gfp)
{
dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
/* If PagePrivate() is set, then the page is not freeable */
if (PagePrivate(page))
return 0;
return nfs_fscache_release_page(page, gfp);
}
void nilfs_invalidatepage(struct page *page, unsigned long offset)
{
struct buffer_head *bh = NULL;
if (PagePrivate(page)) {
bh = page_buffers(page);
BUG_ON(buffer_nilfs_allocated(bh));
}
block_invalidatepage(page, offset);
}
static struct nfs_page *nfs_page_find_request_locked(struct page *page)
{
struct nfs_page *req = NULL;
if (PagePrivate(page)) {
req = (struct nfs_page *)page_private(page);
if (req != NULL)
kref_get(&req->wb_kref);
}
return req;
}
static void print_page(struct page *page)
{
dprintk("PRINTPAGE page %p\n", page);
dprintk(" PagePrivate %d\n", PagePrivate(page));
dprintk(" PageUptodate %d\n", PageUptodate(page));
dprintk(" PageError %d\n", PageError(page));
dprintk(" PageDirty %d\n", PageDirty(page));
dprintk(" PageReferenced %d\n", PageReferenced(page));
dprintk(" PageLocked %d\n", PageLocked(page));
dprintk(" PageWriteback %d\n", PageWriteback(page));
dprintk(" PageMappedToDisk %d\n", PageMappedToDisk(page));
dprintk("\n");
}
/**
* gnttab_free_pages - free pages allocated by gnttab_alloc_pages()
* @nr_pages; number of pages to free
* @pages: the pages
*/
void gnttab_free_pages(int nr_pages, struct page **pages)
{
int i;
for (i = 0; i < nr_pages; i++) {
if (PagePrivate(pages[i])) {
#if BITS_PER_LONG < 64
kfree((void *)page_private(pages[i]));
#endif
ClearPagePrivate(pages[i]);
}
}
free_xenballooned_pages(nr_pages, pages);
}
/*
* This must be called only on pages that have
* been verified to be in the swap cache.
*/
void __delete_from_swap_cache(struct page *page)
{
BUG_ON(!PageLocked(page));
BUG_ON(!PageSwapCache(page));
BUG_ON(PageWriteback(page));
BUG_ON(PagePrivate(page));
radix_tree_delete(&swapper_space.page_tree, page_private(page));
set_page_private(page, 0);
ClearPageSwapCache(page);
total_swapcache_pages--;
__dec_zone_page_state(page, NR_FILE_PAGES);
INC_CACHE_INFO(del_total);
}
/*
* Decide whether a read/modify/write cycle may be more efficient
* then a modify/write/read cycle when writing to a page in the
* page cache.
*
* The modify/write/read cycle may occur if a page is read before
* being completely filled by the writer. In this situation, the
* page must be completely written to stable storage on the server
* before it can be refilled by reading in the page from the server.
* This can lead to expensive, small, FILE_SYNC mode writes being
* done.
*
* It may be more efficient to read the page first if the file is
* open for reading in addition to writing, the page is not marked
* as Uptodate, it is not dirty or waiting to be committed,
* indicating that it was previously allocated and then modified,
* that there were valid bytes of data in that range of the file,
* and that the new data won't completely replace the old data in
* that range of the file.
*/
static int nfs_want_read_modify_write(struct file *file, struct page *page,
loff_t pos, unsigned len)
{
unsigned int pglen = nfs_page_length(page);
unsigned int offset = pos & (PAGE_CACHE_SIZE - 1);
unsigned int end = offset + len;
if ((file->f_mode & FMODE_READ) && /* open for read? */
!PageUptodate(page) && /* Uptodate? */
!PagePrivate(page) && /* i/o request already? */
pglen && /* valid bytes of file? */
(end < pglen || offset)) /* replace all valid bytes? */
return 1;
return 0;
}
/*
* If truncate cannot remove the fs-private metadata from the page, the page
* becomes anonymous. It will be left on the LRU and may even be mapped into
* user pagetables if we're racing with filemap_nopage().
*
* We need to bale out if page->mapping is no longer equal to the original
* mapping. This happens a) when the VM reclaimed the page while we waited on
* its lock, b) when a concurrent invalidate_inode_pages got there first and
* c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
*/
static void
truncate_complete_page(struct address_space *mapping, struct page *page)
{
if (page->mapping != mapping)
return;
if (PagePrivate(page))
do_invalidatepage(page, 0);
clear_page_dirty(page);
ClearPageUptodate(page);
ClearPageMappedToDisk(page);
remove_from_page_cache(page);
page_cache_release(page); /* pagecache ref */
}
/*
* Attempt to steal a page from a pipe buffer. This should perhaps go into
* a vm helper function, it's already simplified quite a bit by the
* addition of remove_mapping(). If success is returned, the caller may
* attempt to reuse this page for another destination.
*/
static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
struct page *page = buf->page;
struct address_space *mapping;
lock_page(page);
mapping = page_mapping(page);
if (mapping) {
WARN_ON(!PageUptodate(page));
/*
* At least for ext2 with nobh option, we need to wait on
* writeback completing on this page, since we'll remove it
* from the pagecache. Otherwise truncate wont wait on the
* page, allowing the disk blocks to be reused by someone else
* before we actually wrote our data to them. fs corruption
* ensues.
*/
wait_on_page_writeback(page);
if (PagePrivate(page)
&& try_to_release_page(page, GFP_KERNEL))
goto out_unlock;
/*
* If we succeeded in removing the mapping, set LRU flag
* and return good.
*/
if (remove_mapping(mapping, page)) {
buf->flags |= PIPE_BUF_FLAG_LRU;
return 0;
}
}
/*
* Raced with truncate or failed to remove page from current
* address space, unlock and return failure.
*/
out_unlock:
unlock_page(page);
return 1;
}
/*
* invalidate part or all of a page
*/
static void afs_file_invalidatepage(struct page *page, unsigned long offset)
{
_enter("{%lu},%lu", page->index, offset);
BUG_ON(!PageLocked(page));
if (PagePrivate(page)) {
/* We release buffers only if the entire page is being
* invalidated.
* The get_block cached value has been unconditionally
* invalidated, so real IO is not possible anymore.
*/
if (offset == 0 && !PageWriteback(page))
page->mapping->a_ops->releasepage(page, 0);
}
_leave("");
} /* end afs_file_invalidatepage() */
int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count)
{
int i, ret = 0;
bool lazy = false;
if (xen_feature(XENFEAT_auto_translated_physmap))
return 0;
if (kmap_ops &&
!in_interrupt() &&
paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
arch_enter_lazy_mmu_mode();
lazy = true;
}
for (i = 0; i < count; i++) {
unsigned long mfn = __pfn_to_mfn(page_to_pfn(pages[i]));
unsigned long pfn = page_to_pfn(pages[i]);
if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) {
ret = -EINVAL;
goto out;
}
set_page_private(pages[i], INVALID_P2M_ENTRY);
WARN_ON(!PagePrivate(pages[i]));
ClearPagePrivate(pages[i]);
set_phys_to_machine(pfn, pages[i]->index);
if (kmap_ops)
ret = m2p_remove_override(pages[i], &kmap_ops[i], mfn);
if (ret)
goto out;
}
out:
if (lazy)
arch_leave_lazy_mmu_mode();
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;
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;
}
