1 files changed, 56 insertions, 68 deletions

diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 55d918fd2d86..cbb7afe7bc46 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -1,29 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Squashfs - a compressed read only filesystem for Linux
  *
  * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
  * Phillip Lougher <phillip@squashfs.org.uk>
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2,
- * or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
  * zlib_wrapper.c
  */
 
 
 #include <linux/mutex.h>
-#include <linux/buffer_head.h>
+#include <linux/bio.h>
 #include <linux/slab.h>
 #include <linux/zlib.h>
 #include <linux/vmalloc.h>
@@ -32,8 +19,9 @@
 #include "squashfs_fs_sb.h"
 #include "squashfs.h"
 #include "decompressor.h"
+#include "page_actor.h"
 
-static void *zlib_init(struct squashfs_sb_info *dummy, void *buff, int len)
+static void *zlib_init(struct squashfs_sb_info *dummy, void *buff)
 {
 	z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
 	if (stream == NULL)
@@ -61,81 +49,80 @@ static void zlib_free(void *strm)
 }
 
 
-static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
-	struct buffer_head **bh, int b, int offset, int length, int srclength,
-	int pages)
+static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm,
+	struct bio *bio, int offset, int length,
+	struct squashfs_page_actor *output)
 {
-	int zlib_err, zlib_init = 0;
-	int k = 0, page = 0;
-	z_stream *stream = msblk->stream;
-
-	mutex_lock(&msblk->read_data_mutex);
+	struct bvec_iter_all iter_all = {};
+	struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
+	int zlib_init = 0, error = 0;
+	z_stream *stream = strm;
 
-	stream->avail_out = 0;
+	stream->avail_out = PAGE_SIZE;
+	stream->next_out = squashfs_first_page(output);
 	stream->avail_in = 0;
 
-	do {
-		if (stream->avail_in == 0 && k < b) {
-			int avail = min(length, msblk->devblksize - offset);
-			length -= avail;
-			wait_on_buffer(bh[k]);
-			if (!buffer_uptodate(bh[k]))
-				goto release_mutex;
+	if (IS_ERR(stream->next_out)) {
+		error = PTR_ERR(stream->next_out);
+		goto finish;
+	}
+
+	for (;;) {
+		int zlib_err;
+
+		if (stream->avail_in == 0) {
+			const void *data;
+			int avail;
+
+			if (!bio_next_segment(bio, &iter_all)) {
+				/* Z_STREAM_END must be reached. */
+				error = -EIO;
+				break;
+			}
 
-			stream->next_in = bh[k]->b_data + offset;
+			avail = min(length, ((int)bvec->bv_len) - offset);
+			data = bvec_virt(bvec);
+			length -= avail;
+			stream->next_in = data + offset;
 			stream->avail_in = avail;
 			offset = 0;
 		}
 
-		if (stream->avail_out == 0 && page < pages) {
-			stream->next_out = buffer[page++];
-			stream->avail_out = PAGE_CACHE_SIZE;
+		if (stream->avail_out == 0) {
+			stream->next_out = squashfs_next_page(output);
+			if (IS_ERR(stream->next_out)) {
+				error = PTR_ERR(stream->next_out);
+				break;
+			} else if (stream->next_out != NULL)
+				stream->avail_out = PAGE_SIZE;
 		}
 
 		if (!zlib_init) {
 			zlib_err = zlib_inflateInit(stream);
 			if (zlib_err != Z_OK) {
-				ERROR("zlib_inflateInit returned unexpected "
-					"result 0x%x, srclength %d\n",
-					zlib_err, srclength);
-				goto release_mutex;
+				error = -EIO;
+				break;
 			}
 			zlib_init = 1;
 		}
 
 		zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
-
-		if (stream->avail_in == 0 && k < b)
-			put_bh(bh[k++]);
-	} while (zlib_err == Z_OK);
-
-	if (zlib_err != Z_STREAM_END) {
-		ERROR("zlib_inflate error, data probably corrupt\n");
-		goto release_mutex;
-	}
-
-	zlib_err = zlib_inflateEnd(stream);
-	if (zlib_err != Z_OK) {
-		ERROR("zlib_inflate error, data probably corrupt\n");
-		goto release_mutex;
-	}
-
-	if (k < b) {
-		ERROR("zlib_uncompress error, data remaining\n");
-		goto release_mutex;
+		if (zlib_err == Z_STREAM_END)
+			break;
+		if (zlib_err != Z_OK) {
+			error = -EIO;
+			break;
+		}
 	}
 
-	length = stream->total_out;
-	mutex_unlock(&msblk->read_data_mutex);
-	return length;
-
-release_mutex:
-	mutex_unlock(&msblk->read_data_mutex);
+finish:
+	squashfs_finish_page(output);
 
-	for (; k < b; k++)
-		put_bh(bh[k]);
+	if (!error)
+		if (zlib_inflateEnd(stream) != Z_OK)
+			error = -EIO;
 
-	return -EIO;
+	return error ? error : stream->total_out;
 }
 
 const struct squashfs_decompressor squashfs_zlib_comp_ops = {
@@ -144,6 +131,7 @@ const struct squashfs_decompressor squashfs_zlib_comp_ops = {
 	.decompress = zlib_uncompress,
 	.id = ZLIB_COMPRESSION,
 	.name = "zlib",
+	.alloc_buffer = 1,
 	.supported = 1
 };