1 files changed, 31 insertions, 36 deletions

diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h
index 279933e007d2..7bfe251680ec 100644
--- a/fs/erofs/compress.h
+++ b/fs/erofs/compress.h
@@ -11,13 +11,12 @@
 struct z_erofs_decompress_req {
 	struct super_block *sb;
 	struct page **in, **out;
-
 	unsigned short pageofs_in, pageofs_out;
 	unsigned int inputsize, outputsize;
 
-	/* indicate the algorithm will be used for decompression */
-	unsigned int alg;
+	unsigned int alg;       /* the algorithm for decompression */
 	bool inplace_io, partial_decoding, fillgaps;
+	gfp_t gfp;      /* allocation flags for extra temporary buffers */
 };
 
 struct z_erofs_decompressor {
@@ -25,6 +24,8 @@ struct z_erofs_decompressor {
 		      void *data, int size);
 	int (*decompress)(struct z_erofs_decompress_req *rq,
 			  struct page **pagepool);
+	int (*init)(void);
+	void (*exit)(void);
 	char *name;
 };
 
@@ -53,17 +54,14 @@ struct z_erofs_decompressor {
  */
 
 /*
- * short-lived pages are pages directly from buddy system with specific
- * page->private (no need to set PagePrivate since these are non-LRU /
- * non-movable pages and bypass reclaim / migration code).
+ * Currently, short-lived pages are pages directly from buddy system
+ * with specific page->private (Z_EROFS_SHORTLIVED_PAGE).
+ * In the future world of Memdescs, it should be type 0 (Misc) memory
+ * which type can be checked with a new helper.
  */
 static inline bool z_erofs_is_shortlived_page(struct page *page)
 {
-	if (page->private != Z_EROFS_SHORTLIVED_PAGE)
-		return false;
-
-	DBG_BUGON(page->mapping);
-	return true;
+	return page->private == Z_EROFS_SHORTLIVED_PAGE;
 }
 
 static inline bool z_erofs_put_shortlivedpage(struct page **pagepool,
@@ -71,35 +69,32 @@ static inline bool z_erofs_put_shortlivedpage(struct page **pagepool,
 {
 	if (!z_erofs_is_shortlived_page(page))
 		return false;
-
-	/* short-lived pages should not be used by others at the same time */
-	if (page_ref_count(page) > 1) {
-		put_page(page);
-	} else {
-		/* follow the pcluster rule above. */
-		erofs_pagepool_add(pagepool, page);
-	}
+	erofs_pagepool_add(pagepool, page);
 	return true;
 }
 
-#define MNGD_MAPPING(sbi)	((sbi)->managed_cache->i_mapping)
-static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi,
-					 struct page *page)
-{
-	return page->mapping == MNGD_MAPPING(sbi);
-}
+extern const struct z_erofs_decompressor z_erofs_lzma_decomp;
+extern const struct z_erofs_decompressor z_erofs_deflate_decomp;
+extern const struct z_erofs_decompressor z_erofs_zstd_decomp;
+extern const struct z_erofs_decompressor *z_erofs_decomp[];
+
+struct z_erofs_stream_dctx {
+	struct z_erofs_decompress_req *rq;
+	unsigned int inpages, outpages;	/* # of {en,de}coded pages */
+	int no, ni;			/* the current {en,de}coded page # */
 
+	unsigned int avail_out;		/* remaining bytes in the decoded buffer */
+	unsigned int inbuf_pos, inbuf_sz;
+					/* current status of the encoded buffer */
+	u8 *kin, *kout;			/* buffer mapped pointers */
+	void *bounce;			/* bounce buffer for inplace I/Os */
+	bool bounced;			/* is the bounce buffer used now? */
+};
+
+int z_erofs_stream_switch_bufs(struct z_erofs_stream_dctx *dctx, void **dst,
+			       void **src, struct page **pgpl);
 int z_erofs_fixup_insize(struct z_erofs_decompress_req *rq, const char *padbuf,
 			 unsigned int padbufsize);
-extern const struct z_erofs_decompressor erofs_decompressors[];
-
-/* prototypes for specific algorithms */
-int z_erofs_load_lzma_config(struct super_block *sb,
-			struct erofs_super_block *dsb, void *data, int size);
-int z_erofs_load_deflate_config(struct super_block *sb,
-			struct erofs_super_block *dsb, void *data, int size);
-int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
-			    struct page **pagepool);
-int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
-			       struct page **pagepool);
+int __init z_erofs_init_decompressor(void);
+void z_erofs_exit_decompressor(void);
 #endif