3  * page.c - buffer/page management specific to NILFS
14 #include <linux/page-flags.h>
20 #include "page.h"
29 __nilfs_get_page_block(struct page *page, unsigned long block, pgoff_t index,  in __nilfs_get_page_block()  argument
36 	if (!page_has_buffers(page))  in __nilfs_get_page_block()
37 		create_empty_buffers(page, 1 << blkbits, b_state);  in __nilfs_get_page_block()
40 	bh = nilfs_page_get_nth_block(page, block - first_block);  in __nilfs_get_page_block()
54 	struct page *page;  in nilfs_grab_buffer()  local
57 	page = grab_cache_page(mapping, index);  in nilfs_grab_buffer()
58 	if (unlikely(!page))  in nilfs_grab_buffer()
61 	bh = __nilfs_get_page_block(page, blkoff, index, blkbits, b_state);  in nilfs_grab_buffer()
63 		unlock_page(page);  in nilfs_grab_buffer()
64 		put_page(page);  in nilfs_grab_buffer()
76 	struct page *page = bh->b_page;  in nilfs_forget_buffer()  local
84 	if (nilfs_page_buffers_clean(page))  in nilfs_forget_buffer()
85 		__nilfs_clear_page_dirty(page);  in nilfs_forget_buffer()
88 	ClearPageUptodate(page);  in nilfs_forget_buffer()
89 	ClearPageMappedToDisk(page);  in nilfs_forget_buffer()
103 	struct page *spage = sbh->b_page, *dpage = dbh->b_page;  in nilfs_copy_buffer()
134  * nilfs_page_buffers_clean - check if a page has dirty buffers or not.
135  * @page: page to be checked
137  * nilfs_page_buffers_clean() returns zero if the page has dirty buffers.
140 int nilfs_page_buffers_clean(struct page *page)  in nilfs_page_buffers_clean()  argument
144 	bh = head = page_buffers(page);  in nilfs_page_buffers_clean()
153 void nilfs_page_bug(struct page *page)  in nilfs_page_bug()  argument
158 	if (unlikely(!page)) {  in nilfs_page_bug()
163 	m = page->mapping;  in nilfs_page_bug()
168 	       page, page_ref_count(page),  in nilfs_page_bug()
169 	       (unsigned long long)page->index, page->flags, m, ino);  in nilfs_page_bug()
171 	if (page_has_buffers(page)) {  in nilfs_page_bug()
175 		bh = head = page_buffers(page);  in nilfs_page_bug()
187  * nilfs_copy_page -- copy the page with buffers
188  * @dst: destination page
189  * @src: source page
190  * @copy_dirty: flag whether to copy dirty states on the page's buffer heads.
193  * should be treated by caller.  The page must not be under i/o.
194  * Both src and dst page must be locked
196 static void nilfs_copy_page(struct page *dst, struct page *src, int copy_dirty)  in nilfs_copy_page()
254 		struct page *page = pvec.pages[i], *dpage;  in nilfs_copy_dirty_pages()  local
256 		lock_page(page);  in nilfs_copy_dirty_pages()
257 		if (unlikely(!PageDirty(page)))  in nilfs_copy_dirty_pages()
258 			NILFS_PAGE_BUG(page, "inconsistent dirty state");  in nilfs_copy_dirty_pages()
260 		dpage = grab_cache_page(dmap, page->index);  in nilfs_copy_dirty_pages()
262 			/* No empty page is added to the page cache */  in nilfs_copy_dirty_pages()
264 			unlock_page(page);  in nilfs_copy_dirty_pages()
267 		if (unlikely(!page_has_buffers(page)))  in nilfs_copy_dirty_pages()
268 			NILFS_PAGE_BUG(page,  in nilfs_copy_dirty_pages()
269 				       "found empty page in dat page cache");  in nilfs_copy_dirty_pages()
271 		nilfs_copy_page(dpage, page, 1);  in nilfs_copy_dirty_pages()
276 		unlock_page(page);  in nilfs_copy_dirty_pages()
288  * @dmap: destination page cache
289  * @smap: source page cache
308 		struct page *page = pvec.pages[i], *dpage;  in nilfs_copy_back_pages()  local
309 		pgoff_t offset = page->index;  in nilfs_copy_back_pages()
311 		lock_page(page);  in nilfs_copy_back_pages()
314 			/* overwrite existing page in the destination cache */  in nilfs_copy_back_pages()
316 			nilfs_copy_page(dpage, page, 0);  in nilfs_copy_back_pages()
319 			/* Do we not need to remove page from smap here? */  in nilfs_copy_back_pages()
321 			struct page *p;  in nilfs_copy_back_pages()
323 			/* move the page to the destination cache */  in nilfs_copy_back_pages()
326 			WARN_ON(page != p);  in nilfs_copy_back_pages()
331 			p = __xa_store(&dmap->i_pages, offset, page, GFP_NOFS);  in nilfs_copy_back_pages()
334 				page->mapping = NULL;  in nilfs_copy_back_pages()
335 				put_page(page);  in nilfs_copy_back_pages()
337 				page->mapping = dmap;  in nilfs_copy_back_pages()
339 				if (PageDirty(page))  in nilfs_copy_back_pages()
345 		unlock_page(page);  in nilfs_copy_back_pages()
369 			struct page *page = pvec.pages[i];  in nilfs_clear_dirty_pages()  local
371 			lock_page(page);  in nilfs_clear_dirty_pages()
372 			nilfs_clear_dirty_page(page, silent);  in nilfs_clear_dirty_pages()
373 			unlock_page(page);  in nilfs_clear_dirty_pages()
381  * nilfs_clear_dirty_page - discard dirty page
382  * @page: dirty page that will be discarded
385 void nilfs_clear_dirty_page(struct page *page, bool silent)  in nilfs_clear_dirty_page()  argument
387 	struct inode *inode = page->mapping->host;  in nilfs_clear_dirty_page()
390 	BUG_ON(!PageLocked(page));  in nilfs_clear_dirty_page()
393 		nilfs_warn(sb, "discard dirty page: offset=%lld, ino=%lu",  in nilfs_clear_dirty_page()
394 			   page_offset(page), inode->i_ino);  in nilfs_clear_dirty_page()
396 	ClearPageUptodate(page);  in nilfs_clear_dirty_page()
397 	ClearPageMappedToDisk(page);  in nilfs_clear_dirty_page()
399 	if (page_has_buffers(page)) {  in nilfs_clear_dirty_page()
406 		bh = head = page_buffers(page);  in nilfs_clear_dirty_page()
419 	__nilfs_clear_page_dirty(page);  in nilfs_clear_dirty_page()
422 unsigned int nilfs_page_count_clean_buffers(struct page *page,  in nilfs_page_count_clean_buffers()  argument
429 	for (bh = head = page_buffers(page), block_start = 0;  in nilfs_page_count_clean_buffers()
452  *    page dirty flags when it copies back pages from the shadow cache
459 int __nilfs_clear_page_dirty(struct page *page)  in __nilfs_clear_page_dirty()  argument
461 	struct address_space *mapping = page->mapping;  in __nilfs_clear_page_dirty()
465 		if (test_bit(PG_dirty, &page->flags)) {  in __nilfs_clear_page_dirty()
466 			__xa_clear_mark(&mapping->i_pages, page_index(page),  in __nilfs_clear_page_dirty()
469 			return clear_page_dirty_for_io(page);  in __nilfs_clear_page_dirty()
474 	return TestClearPageDirty(page);  in __nilfs_clear_page_dirty()
499 	struct page *page;  in nilfs_find_uncommitted_extent()  local
521 		page = pvec.pages[i];  in nilfs_find_uncommitted_extent()
523 		lock_page(page);  in nilfs_find_uncommitted_extent()
524 		if (page_has_buffers(page)) {  in nilfs_find_uncommitted_extent()
527 			bh = head = page_buffers(page);  in nilfs_find_uncommitted_extent()
545 		unlock_page(page);  in nilfs_find_uncommitted_extent()
549 	index = page->index + 1;  in nilfs_find_uncommitted_extent()
555 	unlock_page(page);  in nilfs_find_uncommitted_extent()