8 files changed, 54 insertions, 16 deletions

diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index a5940e54c4d..e921bd21373 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -23,6 +23,7 @@
 
 #include <linux/types.h>
 #include <linux/mutex.h>
+#include <linux/slab.h>
 #include <linux/buffer_head.h>
 
 #include "squashfs_fs.h"
@@ -74,3 +75,36 @@ const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
 
 	return decompressor[i];
 }
+
+
+void *squashfs_decompressor_init(struct super_block *sb, unsigned short flags)
+{
+	struct squashfs_sb_info *msblk = sb->s_fs_info;
+	void *strm, *buffer = NULL;
+	int length = 0;
+
+	/*
+	 * Read decompressor specific options from file system if present
+	 */
+	if (SQUASHFS_COMP_OPTS(flags)) {
+		buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
+		if (buffer == NULL)
+			return ERR_PTR(-ENOMEM);
+
+		length = squashfs_read_data(sb, &buffer,
+			sizeof(struct squashfs_super_block), 0, NULL,
+			PAGE_CACHE_SIZE, 1);
+
+		if (length < 0) {
+			strm = ERR_PTR(length);
+			goto finished;
+		}
+	}
+
+	strm = msblk->decompressor->init(msblk, buffer, length);
+
+finished:
+	kfree(buffer);
+
+	return strm;
+}
diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h
index 3b305a70f7a..099745ad569 100644
--- a/fs/squashfs/decompressor.h
+++ b/fs/squashfs/decompressor.h
@@ -24,7 +24,7 @@
  */
 
 struct squashfs_decompressor {
-	void	*(*init)(struct squashfs_sb_info *);
+	void	*(*init)(struct squashfs_sb_info *, void *, int);
 	void	(*free)(void *);
 	int	(*decompress)(struct squashfs_sb_info *, void **,
 		struct buffer_head **, int, int, int, int, int);
@@ -33,11 +33,6 @@ struct squashfs_decompressor {
 	int	supported;
 };
 
-static inline void *squashfs_decompressor_init(struct squashfs_sb_info *msblk)
-{
-	return msblk->decompressor->init(msblk);
-}
-
 static inline void squashfs_decompressor_free(struct squashfs_sb_info *msblk,
 	void *s)
 {
diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
index 7da759e34c5..00f4dfc5f08 100644
--- a/fs/squashfs/lzo_wrapper.c
+++ b/fs/squashfs/lzo_wrapper.c
@@ -37,7 +37,7 @@ struct squashfs_lzo {
 	void	*output;
 };
 
-static void *lzo_init(struct squashfs_sb_info *msblk)
+static void *lzo_init(struct squashfs_sb_info *msblk, void *buff, int len)
 {
 	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
 
@@ -58,7 +58,7 @@ failed2:
 failed:
 	ERROR("Failed to allocate lzo workspace\n");
 	kfree(stream);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
 
 
diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h
index ba729d80887..1f2e608b878 100644
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -48,6 +48,7 @@ extern int squashfs_read_table(struct super_block *, void *, u64, int);
 
 /* decompressor.c */
 extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int);
+extern void *squashfs_decompressor_init(struct super_block *, unsigned short);
 
 /* export.c */
 extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64,
diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h
index 39533feffd6..4582c568ef4 100644
--- a/fs/squashfs/squashfs_fs.h
+++ b/fs/squashfs/squashfs_fs.h
@@ -57,6 +57,7 @@
 #define SQUASHFS_ALWAYS_FRAG		5
 #define SQUASHFS_DUPLICATE		6
 #define SQUASHFS_EXPORT			7
+#define SQUASHFS_COMP_OPT		10
 
 #define SQUASHFS_BIT(flag, bit)		((flag >> bit) & 1)
 
@@ -81,6 +82,9 @@
 #define SQUASHFS_EXPORTABLE(flags)		SQUASHFS_BIT(flags, \
 						SQUASHFS_EXPORT)
 
+#define SQUASHFS_COMP_OPTS(flags)		SQUASHFS_BIT(flags, \
+						SQUASHFS_COMP_OPT)
+
 /* Max number of types and file types */
 #define SQUASHFS_DIR_TYPE		1
 #define SQUASHFS_REG_TYPE		2
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 20700b9f2b4..95467db71a8 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -199,10 +199,6 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	err = -ENOMEM;
 
-	msblk->stream = squashfs_decompressor_init(msblk);
-	if (msblk->stream == NULL)
-		goto failed_mount;
-
 	msblk->block_cache = squashfs_cache_init("metadata",
 			SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
 	if (msblk->block_cache == NULL)
@@ -215,6 +211,13 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 		goto failed_mount;
 	}
 
+	msblk->stream = squashfs_decompressor_init(sb, flags);
+	if (IS_ERR(msblk->stream)) {
+		err = PTR_ERR(msblk->stream);
+		msblk->stream = NULL;
+		goto failed_mount;
+	}
+
 	/* Allocate and read id index table */
 	msblk->id_table = squashfs_read_id_index_table(sb,
 		le64_to_cpu(sblk->id_table_start), le16_to_cpu(sblk->no_ids));
diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c
index c4eb4001825..397adea72eb 100644
--- a/fs/squashfs/xz_wrapper.c
+++ b/fs/squashfs/xz_wrapper.c
@@ -38,7 +38,8 @@ struct squashfs_xz {
 	struct xz_buf buf;
 };
 
-static void *squashfs_xz_init(struct squashfs_sb_info *msblk)
+static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff,
+	int len)
 {
 	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
 
@@ -55,7 +56,7 @@ static void *squashfs_xz_init(struct squashfs_sb_info *msblk)
 failed:
 	ERROR("Failed to allocate xz workspace\n");
 	kfree(stream);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
 
 
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 4661ae2b1ce..195b0d035e9 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -32,7 +32,7 @@
 #include "squashfs.h"
 #include "decompressor.h"
 
-static void *zlib_init(struct squashfs_sb_info *dummy)
+static void *zlib_init(struct squashfs_sb_info *dummy, void *buff, int len)
 {
 	z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
 	if (stream == NULL)
@@ -47,7 +47,7 @@ static void *zlib_init(struct squashfs_sb_info *dummy)
 failed:
 	ERROR("Failed to allocate zlib workspace\n");
 	kfree(stream);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }