erofs: clean up preload_compressed_pages()

Rename preload_compressed_pages() as z_erofs_bind_cache()
since we're trying to prepare for adapting folios.

Also, add a comment for the gfp setting. No logic changes.

Link: https://lore.kernel.org/r/20220301194951.106227-2-hsiangkao@linux.alibaba.com
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 2673fc1..59aecf4 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -219,13 +219,17 @@ struct z_erofs_decompress_frontend {
 static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
 static DEFINE_MUTEX(z_pagemap_global_lock);
 
-static void preload_compressed_pages(struct z_erofs_decompress_frontend *fe,
-                                    struct address_space *mc,
-                                    enum z_erofs_cache_alloctype type,
-                                    struct page **pagepool)
+static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe,
+                              enum z_erofs_cache_alloctype type,
+                              struct page **pagepool)
 {
+       struct address_space *mc = MNGD_MAPPING(EROFS_I_SB(fe->inode));
        struct z_erofs_pcluster *pcl = fe->pcl;
        bool standalone = true;
+       /*
+        * optimistic allocation without direct reclaim since inplace I/O
+        * can be used if low memory otherwise.
+        */
        gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) |
                        __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
        struct page **pages;
@@ -703,17 +707,15 @@ restart_now:
                WRITE_ONCE(fe->pcl->compressed_pages[0], fe->map.buf.page);
                fe->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
        } else {
-               /* preload all compressed pages (can change mode if needed) */
+               /* bind cache first when cached decompression is preferred */
                if (should_alloc_managed_pages(fe, sbi->opt.cache_strategy,
                                               map->m_la))
                        cache_strategy = TRYALLOC;
                else
                        cache_strategy = DONTALLOC;
 
-               preload_compressed_pages(fe, MNGD_MAPPING(sbi),
-                                        cache_strategy, pagepool);
+               z_erofs_bind_cache(fe, cache_strategy, pagepool);
        }
-
 hitted:
        /*
         * Ensure the current partial page belongs to this submit chain rather