erofs: convert z_erofs_onlinepage_.* to folios

Online folios are locked file-backed folios which will eventually
keep decoded (e.g. decompressed) data of each inode for end users to
utilize.  It may belong to a few pclusters and contain other data (e.g.
compressed data for inplace I/Os) temporarily in a time-sharing manner
to reduce memory footprints for low-ended storage devices with high
latencies under heary I/O pressure.

Apart from folio_end_read() usage, it's a straight-forward conversion.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240305091448.1384242-1-hsiangkao@linux.alibaba.com

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index ff0aa72b0db342f10ed7c1b565d2cc7bd6a540ff..5013fcd4965aee1d4f5bd27dcb2d9967f8828256 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -117,46 +117,39 @@ static inline unsigned int z_erofs_pclusterpages(struct z_erofs_pcluster *pcl)
 }
 
 /*
- * bit 30: I/O error occurred on this page
- * bit 0 - 29: remaining parts to complete this page
+ * bit 30: I/O error occurred on this folio
+ * bit 0 - 29: remaining parts to complete this folio
  */
-#define Z_EROFS_PAGE_EIO                       (1 << 30)
+#define Z_EROFS_FOLIO_EIO                      (1 << 30)
 
-static inline void z_erofs_onlinepage_init(struct page *page)
+static void z_erofs_onlinefolio_init(struct folio *folio)
 {
        union {
                atomic_t o;
-               unsigned long v;
+               void *v;
        } u = { .o = ATOMIC_INIT(1) };
 
-       set_page_private(page, u.v);
-       smp_wmb();
-       SetPagePrivate(page);
+       folio->private = u.v;   /* valid only if file-backed folio is locked */
 }
 
-static inline void z_erofs_onlinepage_split(struct page *page)
+static void z_erofs_onlinefolio_split(struct folio *folio)
 {
-       atomic_inc((atomic_t *)&page->private);
+       atomic_inc((atomic_t *)&folio->private);
 }
 
-static void z_erofs_onlinepage_endio(struct page *page, int err)
+static void z_erofs_onlinefolio_end(struct folio *folio, int err)
 {
        int orig, v;
 
-       DBG_BUGON(!PagePrivate(page));
-
        do {
-               orig = atomic_read((atomic_t *)&page->private);
-               v = (orig - 1) | (err ? Z_EROFS_PAGE_EIO : 0);
-       } while (atomic_cmpxchg((atomic_t *)&page->private, orig, v) != orig);
+               orig = atomic_read((atomic_t *)&folio->private);
+               v = (orig - 1) | (err ? Z_EROFS_FOLIO_EIO : 0);
+       } while (atomic_cmpxchg((atomic_t *)&folio->private, orig, v) != orig);
 
-       if (!(v & ~Z_EROFS_PAGE_EIO)) {
-               set_page_private(page, 0);
-               ClearPagePrivate(page);
-               if (!(v & Z_EROFS_PAGE_EIO))
-                       SetPageUptodate(page);
-               unlock_page(page);
-       }
+       if (v & ~Z_EROFS_FOLIO_EIO)
+               return;
+       folio->private = 0;
+       folio_end_read(folio, !(v & Z_EROFS_FOLIO_EIO));
 }
 
 #define Z_EROFS_ONSTACK_PAGES          32
@@ -965,6 +958,7 @@ static int z_erofs_read_fragment(struct super_block *sb, struct page *page,
 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
                                struct page *page, bool ra)
 {
+       struct folio *folio = page_folio(page);
        struct inode *const inode = fe->inode;
        struct erofs_map_blocks *const map = &fe->map;
        const loff_t offset = page_offset(page);
@@ -973,7 +967,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
        unsigned int cur, end, len, split;
        int err = 0;
 
-       z_erofs_onlinepage_init(page);
+       z_erofs_onlinefolio_init(folio);
        split = 0;
        end = PAGE_SIZE;
 repeat:
@@ -1035,7 +1029,7 @@ repeat:
        if (err)
                goto out;
 
-       z_erofs_onlinepage_split(page);
+       z_erofs_onlinefolio_split(folio);
        if (fe->pcl->pageofs_out != (map->m_la & ~PAGE_MASK))
                fe->pcl->multibases = true;
        if (fe->pcl->length < offset + end - map->m_la) {
@@ -1056,7 +1050,7 @@ next_part:
                goto repeat;
 
 out:
-       z_erofs_onlinepage_endio(page, err);
+       z_erofs_onlinefolio_end(folio, err);
        return err;
 }
 
@@ -1159,7 +1153,7 @@ static void z_erofs_fill_other_copies(struct z_erofs_decompress_backend *be,
                        cur += len;
                }
                kunmap_local(dst);
-               z_erofs_onlinepage_endio(bvi->bvec.page, err);
+               z_erofs_onlinefolio_end(page_folio(bvi->bvec.page), err);
                list_del(p);
                kfree(bvi);
        }
@@ -1316,7 +1310,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
                /* recycle all individual short-lived pages */
                if (z_erofs_put_shortlivedpage(be->pagepool, page))
                        continue;
-               z_erofs_onlinepage_endio(page, err);
+               z_erofs_onlinefolio_end(page_folio(page), err);
        }
 
        if (be->decompressed_pages != be->onstack_pages)