Squashfs: factor out remaining zlib dependencies into separate wrapper file

Move zlib buffer init/destroy code into separate wrapper file.  Also
make zlib z_stream field a void * removing the need to include zlib.h
for most files.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

fs/squashfs/block.c

@@ -31,7 +31,6 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/buffer_head.h>
-#include <linux/zlib.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"

fs/squashfs/cache.c

@@ -51,7 +51,6 @@
 #include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
-#include <linux/zlib.h>
 #include <linux/pagemap.h>
 
 #include "squashfs_fs.h"

fs/squashfs/dir.c

@@ -30,7 +30,6 @@
 #include <linux/fs.h>
 #include <linux/vfs.h>
 #include <linux/slab.h>
-#include <linux/zlib.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"

fs/squashfs/export.c

@@ -39,7 +39,6 @@
 #include <linux/vfs.h>
 #include <linux/dcache.h>
 #include <linux/exportfs.h>
-#include <linux/zlib.h>
 #include <linux/slab.h>
 
 #include "squashfs_fs.h"

fs/squashfs/file.c

@@ -47,7 +47,6 @@
 #include <linux/string.h>
 #include <linux/pagemap.h>
 #include <linux/mutex.h>
-#include <linux/zlib.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"

fs/squashfs/fragment.c

@@ -36,7 +36,6 @@
 #include <linux/fs.h>
 #include <linux/vfs.h>
 #include <linux/slab.h>
-#include <linux/zlib.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"

fs/squashfs/id.c

@@ -34,7 +34,6 @@
 #include <linux/fs.h>
 #include <linux/vfs.h>
 #include <linux/slab.h>
-#include <linux/zlib.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"

fs/squashfs/inode.c

@@ -40,7 +40,6 @@
 
 #include <linux/fs.h>
 #include <linux/vfs.h>
-#include <linux/zlib.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"

fs/squashfs/namei.c

@@ -57,7 +57,6 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/dcache.h>
-#include <linux/zlib.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"

fs/squashfs/squashfs.h

@@ -71,6 +71,8 @@ extern struct inode *squashfs_iget(struct super_block *, long long,
 extern int squashfs_read_inode(struct inode *, long long);
 
 /* zlib_wrapper.c */
+extern void *squashfs_zlib_init(void);
+extern void squashfs_zlib_free(void *);
 extern int squashfs_zlib_uncompress(struct squashfs_sb_info *, void **,
 				struct buffer_head **, int, int, int, int, int);
 

fs/squashfs/squashfs_fs_sb.h

@@ -64,7 +64,7 @@ struct squashfs_sb_info {
 	struct mutex		read_data_mutex;
 	struct mutex		meta_index_mutex;
 	struct meta_index	*meta_index;
-	z_stream		stream;
+	void			*stream;
 	__le64			*inode_lookup_table;
 	u64			inode_table;
 	u64			directory_table;

fs/squashfs/super.c

@@ -35,7 +35,6 @@
 #include <linux/pagemap.h>
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/zlib.h>
 #include <linux/magic.h>
 
 #include "squashfs_fs.h"
@@ -87,12 +86,9 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 	}
 	msblk = sb->s_fs_info;
 
-	msblk->stream.workspace = kmalloc(zlib_inflate_workspacesize(),
-		GFP_KERNEL);
-	if (msblk->stream.workspace == NULL) {
-		ERROR("Failed to allocate zlib workspace\n");
+	msblk->stream = squashfs_zlib_init();
+	if (msblk->stream == NULL)
 		goto failure;
-	}
 
 	sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
 	if (sblk == NULL) {
@@ -292,17 +288,17 @@ failed_mount:
 	squashfs_cache_delete(msblk->block_cache);
 	squashfs_cache_delete(msblk->fragment_cache);
 	squashfs_cache_delete(msblk->read_page);
+	squashfs_zlib_free(msblk->stream);
 	kfree(msblk->inode_lookup_table);
 	kfree(msblk->fragment_index);
 	kfree(msblk->id_table);
-	kfree(msblk->stream.workspace);
 	kfree(sb->s_fs_info);
 	sb->s_fs_info = NULL;
 	kfree(sblk);
 	return err;
 
 failure:
-	kfree(msblk->stream.workspace);
+	squashfs_zlib_free(msblk->stream);
 	kfree(sb->s_fs_info);
 	sb->s_fs_info = NULL;
 	return -ENOMEM;
@@ -346,10 +342,10 @@ static void squashfs_put_super(struct super_block *sb)
 		squashfs_cache_delete(sbi->block_cache);
 		squashfs_cache_delete(sbi->fragment_cache);
 		squashfs_cache_delete(sbi->read_page);
+		squashfs_zlib_free(sbi->stream);
 		kfree(sbi->id_table);
 		kfree(sbi->fragment_index);
 		kfree(sbi->meta_index);
-		kfree(sbi->stream.workspace);
 		kfree(sb->s_fs_info);
 		sb->s_fs_info = NULL;
 	}

fs/squashfs/symlink.c

@@ -36,7 +36,6 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/pagemap.h>
-#include <linux/zlib.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"

fs/squashfs/zlib_wrapper.c

@@ -31,21 +31,51 @@
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
 
+void *squashfs_zlib_init()
+{
+	z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
+	if (stream == NULL)
+		goto failed;
+	stream->workspace = kmalloc(zlib_inflate_workspacesize(),
+		GFP_KERNEL);
+	if (stream->workspace == NULL)
+		goto failed;
+
+	return stream;
+
+failed:
+	ERROR("Failed to allocate zlib workspace\n");
+	kfree(stream);
+	return NULL;
+}
+
+
+void squashfs_zlib_free(void *strm)
+{
+	z_stream *stream = strm;
+
+	if (stream)
+		kfree(stream->workspace);
+	kfree(stream);
+}
+
+
 int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 	struct buffer_head **bh, int b, int offset, int length, int srclength,
 	int pages)
 {
 	int zlib_err = 0, zlib_init = 0;
 	int avail, bytes, k = 0, page = 0;
+	z_stream *stream = msblk->stream;
 
 	mutex_lock(&msblk->read_data_mutex);
 
-	msblk->stream.avail_out = 0;
-	msblk->stream.avail_in = 0;
+	stream->avail_out = 0;
+	stream->avail_in = 0;
 
 	bytes = length;
 	do {
-		if (msblk->stream.avail_in == 0 && k < b) {
+		if (stream->avail_in == 0 && k < b) {
 			avail = min(bytes, msblk->devblksize - offset);
 			bytes -= avail;
 			wait_on_buffer(bh[k]);
@@ -58,18 +88,18 @@ int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 				continue;
 			}
 
-			msblk->stream.next_in = bh[k]->b_data + offset;
-			msblk->stream.avail_in = avail;
+			stream->next_in = bh[k]->b_data + offset;
+			stream->avail_in = avail;
 			offset = 0;
 		}
 
-		if (msblk->stream.avail_out == 0 && page < pages) {
-			msblk->stream.next_out = buffer[page++];
-			msblk->stream.avail_out = PAGE_CACHE_SIZE;
+		if (stream->avail_out == 0 && page < pages) {
+			stream->next_out = buffer[page++];
+			stream->avail_out = PAGE_CACHE_SIZE;
 		}
 
 		if (!zlib_init) {
-			zlib_err = zlib_inflateInit(&msblk->stream);
+			zlib_err = zlib_inflateInit(stream);
 			if (zlib_err != Z_OK) {
 				ERROR("zlib_inflateInit returned unexpected "
 					"result 0x%x, srclength %d\n",
@@ -79,9 +109,9 @@ int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 			zlib_init = 1;
 		}
 
-		zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH);
+		zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
 
-		if (msblk->stream.avail_in == 0 && k < b)
+		if (stream->avail_in == 0 && k < b)
 			put_bh(bh[k++]);
 	} while (zlib_err == Z_OK);
 
@@ -90,14 +120,14 @@ int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 		goto release_mutex;
 	}
 
-	zlib_err = zlib_inflateEnd(&msblk->stream);
+	zlib_err = zlib_inflateEnd(stream);
 	if (zlib_err != Z_OK) {
 		ERROR("zlib_inflate error, data probably corrupt\n");
 		goto release_mutex;
 	}
 
 	mutex_unlock(&msblk->read_data_mutex);
-	return msblk->stream.total_out;
+	return stream->total_out;
 
 release_mutex:
 	mutex_unlock(&msblk->read_data_mutex);