btrfs: convert defrag_prepare_one_page() to use a folio

Use a folio throughout defrag_prepare_one_page() to remove dozens of
hidden calls to compound_head().  There is no support here for large
folios; indeed, turn the existing check for PageCompound into a check
for large folios.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/defrag.c b/fs/btrfs/defrag.c
index 5b0b645714183a7adcbe093d48964ee7380c4b24..fc5950776156eb8c06fd33fcf4196faeca9e8718 100644 (file)
--- a/fs/btrfs/defrag.c
+++ b/fs/btrfs/defrag.c
@@ -868,13 +868,14 @@ static struct page *defrag_prepare_one_page(struct btrfs_inode *inode, pgoff_t i
        u64 page_start = (u64)index << PAGE_SHIFT;
        u64 page_end = page_start + PAGE_SIZE - 1;
        struct extent_state *cached_state = NULL;
-       struct page *page;
+       struct folio *folio;
        int ret;
 
 again:
-       page = find_or_create_page(mapping, index, mask);
-       if (!page)
-               return ERR_PTR(-ENOMEM);
+       folio = __filemap_get_folio(mapping, index,
+                                   FGP_LOCK | FGP_ACCESSED | FGP_CREAT, mask);
+       if (IS_ERR(folio))
+               return &folio->page;
 
        /*
         * Since we can defragment files opened read-only, we can encounter
@@ -884,16 +885,16 @@ again:
         * executables that explicitly enable them, so this isn't very
         * restrictive.
         */
-       if (PageCompound(page)) {
-               unlock_page(page);
-               put_page(page);
+       if (folio_test_large(folio)) {
+               folio_unlock(folio);
+               folio_put(folio);
                return ERR_PTR(-ETXTBSY);
        }
 
-       ret = set_page_extent_mapped(page);
+       ret = set_folio_extent_mapped(folio);
        if (ret < 0) {
-               unlock_page(page);
-               put_page(page);
+               folio_unlock(folio);
+               folio_put(folio);
                return ERR_PTR(ret);
        }
 
@@ -908,17 +909,17 @@ again:
                if (!ordered)
                        break;
 
-               unlock_page(page);
+               folio_unlock(folio);
                btrfs_start_ordered_extent(ordered);
                btrfs_put_ordered_extent(ordered);
-               lock_page(page);
+               folio_lock(folio);
                /*
-                * We unlocked the page above, so we need check if it was
+                * We unlocked the folio above, so we need check if it was
                 * released or not.
                 */
-               if (page->mapping != mapping || !PagePrivate(page)) {
-                       unlock_page(page);
-                       put_page(page);
+               if (folio->mapping != mapping || !folio->private) {
+                       folio_unlock(folio);
+                       folio_put(folio);
                        goto again;
                }
        }
@@ -927,21 +928,21 @@ again:
         * Now the page range has no ordered extent any more.  Read the page to
         * make it uptodate.
         */
-       if (!PageUptodate(page)) {
-               btrfs_read_folio(NULL, page_folio(page));
-               lock_page(page);
-               if (page->mapping != mapping || !PagePrivate(page)) {
-                       unlock_page(page);
-                       put_page(page);
+       if (!folio_test_uptodate(folio)) {
+               btrfs_read_folio(NULL, folio);
+               folio_lock(folio);
+               if (folio->mapping != mapping || !folio->private) {
+                       folio_unlock(folio);
+                       folio_put(folio);
                        goto again;
                }
-               if (!PageUptodate(page)) {
-                       unlock_page(page);
-                       put_page(page);
+               if (!folio_test_uptodate(folio)) {
+                       folio_unlock(folio);
+                       folio_put(folio);
                        return ERR_PTR(-EIO);
                }
        }
-       return page;
+       return &folio->page;
 }
 
 struct defrag_target_range {