Unverified Commit 0ee818cc authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Christian Brauner
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jffs2: Convert jffs2_write_begin() to use a folio 



Fetch a folio from the page cache instead of a page and use it throughout
removing several calls to compound_head().  We still have to convert
back to a page for calling internal jffs2 functions, but hopefully they
will be converted soon.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent c8dbe54a

fs/jffs2/file.c

+13 −12
Original line number Diff line number Diff line
@@ -127,7 +127,7 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping, 
			loff_t pos, unsigned len,

			struct page **pagep, void **fsdata)

{

	struct page *pg;

	struct folio *folio;

	struct inode *inode = mapping->host;

	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);

	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
@@ -206,29 +206,30 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping, 
	 * page in read_cache_page(), which causes a deadlock.

	 */

	mutex_lock(&c->alloc_sem);

	pg = grab_cache_page_write_begin(mapping, index);

	if (!pg) {

		ret = -ENOMEM;

	folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,

			mapping_gfp_mask(mapping));

	if (IS_ERR(folio)) {

		ret = PTR_ERR(folio);

		goto release_sem;

	}

	*pagep = pg;

	*pagep = &folio->page;



	/*

	 * Read in the page if it wasn't already present. Cannot optimize away

	 * the whole page write case until jffs2_write_end can handle the

	 * Read in the folio if it wasn't already present. Cannot optimize away

	 * the whole folio write case until jffs2_write_end can handle the

	 * case of a short-copy.

	 */

	if (!PageUptodate(pg)) {

	if (!folio_test_uptodate(folio)) {

		mutex_lock(&f->sem);

		ret = jffs2_do_readpage_nolock(inode, pg);

		ret = jffs2_do_readpage_nolock(inode, &folio->page);

		mutex_unlock(&f->sem);

		if (ret) {

			unlock_page(pg);

			put_page(pg);

			folio_unlock(folio);

			folio_put(folio);

			goto release_sem;

		}

	}

	jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);

	jffs2_dbg(1, "end write_begin(). folio->flags %lx\n", folio->flags);



release_sem:

	mutex_unlock(&c->alloc_sem);