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: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2024-07-11 16:58:06 -04:00 committed by Christian Brauner
parent c8dbe54a2e
commit 0ee818cc42
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@ -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);