From 846b730e99518a1c9945afcb2afbe4d08a02ed80 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Mon, 18 Nov 2013 02:59:12 +0000 Subject: 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 Reviewed-by: Minchan Kim --- fs/squashfs/xz_wrapper.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) (limited to 'fs/squashfs/xz_wrapper.c') diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c index 5d1d07cca6b4..c609624e4b8a 100644 --- a/fs/squashfs/xz_wrapper.c +++ b/fs/squashfs/xz_wrapper.c @@ -32,6 +32,7 @@ #include "squashfs_fs_sb.h" #include "squashfs.h" #include "decompressor.h" +#include "page_actor.h" struct squashfs_xz { struct xz_dec *state; @@ -129,11 +130,11 @@ static void squashfs_xz_free(void *strm) static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm, - void **buffer, struct buffer_head **bh, int b, int offset, int length, - int srclength, int pages) + struct buffer_head **bh, int b, int offset, int length, + struct squashfs_page_actor *output) { enum xz_ret xz_err; - int avail, total = 0, k = 0, page = 0; + int avail, total = 0, k = 0; struct squashfs_xz *stream = strm; xz_dec_reset(stream->state); @@ -141,7 +142,7 @@ static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm, stream->buf.in_size = 0; stream->buf.out_pos = 0; stream->buf.out_size = PAGE_CACHE_SIZE; - stream->buf.out = buffer[page++]; + stream->buf.out = squashfs_first_page(output); do { if (stream->buf.in_pos == stream->buf.in_size && k < b) { @@ -153,11 +154,12 @@ static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm, offset = 0; } - if (stream->buf.out_pos == stream->buf.out_size - && page < pages) { - stream->buf.out = buffer[page++]; - stream->buf.out_pos = 0; - total += PAGE_CACHE_SIZE; + if (stream->buf.out_pos == stream->buf.out_size) { + stream->buf.out = squashfs_next_page(output); + if (stream->buf.out != NULL) { + stream->buf.out_pos = 0; + total += PAGE_CACHE_SIZE; + } } xz_err = xz_dec_run(stream->state, &stream->buf); @@ -166,6 +168,8 @@ static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm, put_bh(bh[k++]); } while (xz_err == XZ_OK); + squashfs_finish_page(output); + if (xz_err != XZ_STREAM_END || k < b) goto out; -- cgit v1.2.3