/**
* invalidate_inode_pages2 - remove all unmapped pages from an address_space
* @mapping - the address_space
*
* invalidate_inode_pages2() is like truncate_inode_pages(), except for the case
* where the page is seen to be mapped into process pagetables. In that case,
* the page is marked clean but is left attached to its address_space.
*
* The page is also marked not uptodate so that a subsequent pagefault will
* perform I/O to bringthe page's contents back into sync with its backing
* store.
*
* FIXME: invalidate_inode_pages2() is probably trivially livelockable.
*/
void invalidate_inode_pages2(struct address_space *mapping)
{
struct pagevec pvec;
pgoff_t next = 0;
int i;
pagevec_init(&pvec, 0);
while (pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
for (i = 0; i < pagevec_count(&pvec); i++) {
struct page *page = pvec.pages[i];
lock_page(page);
if (page->mapping == mapping) { /* truncate race? */
wait_on_page_writeback(page);
next = page->index + 1;
if (page_mapped(page)) {
clear_page_dirty(page);
ClearPageUptodate(page);
} else {
if (!invalidate_complete_page(mapping,
page)) {
clear_page_dirty(page);
ClearPageUptodate(page);
}
}
}
unlock_page(page);
}
pagevec_release(&pvec);
cond_resched();
}
}
static void
unmap_buffers(struct page *page, loff_t pos) {
struct buffer_head *bh ;
struct buffer_head *head ;
struct buffer_head *next ;
unsigned long tail_index ;
unsigned long cur_index ;
if (page) {
if (page_has_buffers(page)) {
tail_index = pos & (PAGE_CACHE_SIZE - 1) ;
cur_index = 0 ;
head = page_buffers(page) ;
bh = head ;
do {
next = bh->b_this_page ;
/* we want to unmap the buffers that contain the tail, and
** all the buffers after it (since the tail must be at the
** end of the file). We don't want to unmap file data
** before the tail, since it might be dirty and waiting to
** reach disk
*/
cur_index += bh->b_size ;
if (cur_index > tail_index) {
reiserfs_unmap_buffer(bh) ;
}
bh = next ;
} while (bh != head) ;
if ( PAGE_SIZE == bh->b_size ) {
clear_page_dirty(page);
}
}
}
}
/*
* 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 */
}
static int fuse_commit_write(struct file *file, struct page *page,
unsigned offset, unsigned to)
{
int err;
size_t nres;
unsigned count = to - offset;
struct inode *inode = page->mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
loff_t pos = page_offset(page) + offset;
struct fuse_req *req;
if (is_bad_inode(inode))
return -EIO;
req = fuse_get_request(fc);
if (!req)
return -EINTR;
req->num_pages = 1;
req->pages[0] = page;
req->page_offset = offset;
nres = fuse_send_write(req, file, inode, pos, count);
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err && nres != count)
err = -EIO;
if (!err) {
pos += count;
if (pos > i_size_read(inode))
i_size_write(inode, pos);
if (offset == 0 && to == PAGE_CACHE_SIZE) {
clear_page_dirty(page);
SetPageUptodate(page);
}
}
fuse_invalidate_attr(inode);
return err;
}
