Squashfs: Generalise paging handling in the decompressors

Further generalise the decompressors by adding a page handler
abstraction.  This adds helpers to allow the decompressors
to access and process the output buffers in an implementation
independant manner.

This allows different types of output buffer to be passed
to the decompressors, with the implementation specific
aspects handled at decompression time, but without the
knowledge being held in the decompressor wrapper code.

This will allow the decompressors to handle Squashfs
cache buffers, and page cache pages.

This patch adds the abstraction and an implementation for
the caches.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: Minchan Kim <minchan@kernel.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h
index 2e2751df8452..6a97e63ca173 100644
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -28,8 +28,8 @@
 #define WARNING(s, args...)     pr_warning("SQUASHFS: "s, ## args)
 
 /* block.c */
-extern int squashfs_read_data(struct super_block *, void **, u64, int, u64 *,
-                                int, int);
+extern int squashfs_read_data(struct super_block *, u64, int, u64 *,
+                                struct squashfs_page_actor *);
 
 /* cache.c */
 extern struct squashfs_cache *squashfs_cache_init(char *, int, int);
@@ -53,8 +53,8 @@ extern void *squashfs_decompressor_setup(struct super_block *, unsigned short);
 /* decompressor_xxx.c */
 extern void *squashfs_decompressor_create(struct squashfs_sb_info *, void *);
 extern void squashfs_decompressor_destroy(struct squashfs_sb_info *);
-extern int squashfs_decompress(struct squashfs_sb_info *, void **,
-        struct buffer_head **, int, int, int, int, int);
+extern int squashfs_decompress(struct squashfs_sb_info *, struct buffer_head **,
+        int, int, int, struct squashfs_page_actor *);
 extern int squashfs_max_decompressors(void);
 
 /* export.c */