[PATCH/RFC 8/8] squashfs: Make SquashFS 4 use the new pcomp crypto interface

[Geert Uytterhoeven]

From: Geert Uytterhoeven <Geert.Uytterhoeven@xxxxxxxxxxx>

Modify SquashFS 4 to use the new "pcomp" crypto interface for decompression,
instead of calling the underlying zlib library directly. This simplifies e.g.
the addition of support for hardware decompression and different decompression
algorithms.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@xxxxxxxxxxx>
CC: Phillip Lougher <phillip@xxxxxxxxxxxxxxxxxxx>
---
 fs/Kconfig                   |    3 +
 fs/squashfs/block.c          |   67 +++++++++++++++++++++++++------------------
 fs/squashfs/squashfs_fs_sb.h |    2 -
 fs/squashfs/super.c          |   33 ++++++++++++++++-----
 4 files changed, 69 insertions(+), 36 deletions(-)

--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -934,7 +934,8 @@ config CRAMFS
 config SQUASHFS
 	tristate "SquashFS 4.0 - Squashed file system support"
 	depends on BLOCK
-	select ZLIB_INFLATE
+	select CRYPTO
+	select CRYPTO_DEFLATE
 	help
 	  Saying Y here includes support for SquashFS 4.0 (a Compressed
 	  Read-Only File System).  Squashfs is a highly compressed read-only
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -32,7 +32,7 @@
 #include <linux/mutex.h>
 #include <linux/string.h>
 #include <linux/buffer_head.h>
-#include <linux/zlib.h>
+#include <linux/crypto.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
@@ -150,7 +150,8 @@ int squashfs_read_data(struct super_bloc
 	}
 
 	if (compressed) {
-		int zlib_err = 0;
+		int error = 0;
+		struct comp_request req;
 
 		/*
 		 * Uncompress block.
@@ -158,8 +159,8 @@ int squashfs_read_data(struct super_bloc
 
 		mutex_lock(&msblk->read_data_mutex);
 
-		msblk->stream.next_out = buffer;
-		msblk->stream.avail_out = srclength;
+		req.next_out = buffer;
+		req.avail_out = srclength;
 
 		for (bytes = 0; k < b; k++) {
 			avail = min(c_byte - bytes, msblk->devblksize - offset);
@@ -168,16 +169,19 @@ int squashfs_read_data(struct super_bloc
 			if (!buffer_uptodate(bh[k]))
 				goto release_mutex;
 
-			msblk->stream.next_in = bh[k]->b_data + offset;
-			msblk->stream.avail_in = avail;
+			req.next_in = bh[k]->b_data + offset;
+			req.avail_in = avail;
 
 			if (k == 0) {
-				zlib_err = zlib_inflateInit(&msblk->stream);
-				if (zlib_err != Z_OK) {
-					ERROR("zlib_inflateInit returned"
-						" unexpected result 0x%x,"
-						" srclength %d\n", zlib_err,
-						srclength);
+				error = crypto_pcomp_decompress_init(msblk->tfm,
+								     &req);
+				if (error && error != -EAGAIN) {
+					ERROR("crypto_pcomp_decompress_init "
+					      "returned unexpected result %d, "
+					      "srclength %d, avail_in %u, "
+					      "avail_out %u\n",
+					      error, srclength, req.avail_in,
+					      req.avail_out);
 					goto release_mutex;
 				}
 
@@ -186,15 +190,25 @@ int squashfs_read_data(struct super_bloc
 					brelse(bh[k]);
 					continue;
 				}
+
+			} else {
+				error = crypto_pcomp_decompress_update(msblk->tfm,
+								       &req);
+				if (error) {
+					ERROR("crypto_pcomp_decompress_update "
+					      "returned unexpected result %d, "
+					      "srclength %d, avail_in %u, "
+					      "avail_out %u\n",
+					      error, srclength, req.avail_in,
+					      req.avail_out);
+					goto release_mutex;
+				}
 			}
 
-			zlib_err = zlib_inflate(&msblk->stream, Z_NO_FLUSH);
-			if (zlib_err != Z_OK && zlib_err != Z_STREAM_END) {
-				ERROR("zlib_inflate returned unexpected result"
-					" 0x%x, srclength %d, avail_in %d,"
-					" avail_out %d\n", zlib_err, srclength,
-					msblk->stream.avail_in,
-					msblk->stream.avail_out);
+			if (req.avail_in) {
+				ERROR("crypto_pcomp_decompress_* did not "
+				      "consume all input data (%u left)\n",
+				      req.avail_in);
 				goto release_mutex;
 			}
 
@@ -203,16 +217,15 @@ int squashfs_read_data(struct super_bloc
 			brelse(bh[k]);
 		}
 
-		if (zlib_err != Z_STREAM_END)
-			goto release_mutex;
-
-		zlib_err = zlib_inflateEnd(&msblk->stream);
-		if (zlib_err != Z_OK) {
-			ERROR("zlib_inflateEnd returned unexpected result 0x%x,"
-				" srclength %d\n", zlib_err, srclength);
+		error = crypto_pcomp_decompress_final(msblk->tfm, &req);
+		if (error) {
+			ERROR("crypto_pcomp_decompress_final returned "
+			      "unexpected result %d, srclength %d, avail_in "
+			      "%u, avail_out %u\n",
+			      error, srclength, req.avail_in, req.avail_out);
 			goto release_mutex;
 		}
-		bytes = msblk->stream.total_out;
+		bytes = req.next_out - buffer;
 		mutex_unlock(&msblk->read_data_mutex);
 	} else {
 		/*
--- a/fs/squashfs/squashfs_fs_sb.h
+++ b/fs/squashfs/squashfs_fs_sb.h
@@ -63,7 +63,7 @@ struct squashfs_sb_info {
 	struct mutex		read_data_mutex;
 	struct mutex		meta_index_mutex;
 	struct meta_index	*meta_index;
-	z_stream		stream;
+	struct crypto_pcomp	*tfm;
 	__le64			*inode_lookup_table;
 	long long		inode_table;
 	long long		directory_table;
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -35,6 +35,7 @@
 #include <linux/pagemap.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/crypto.h>
 #include <linux/zlib.h>
 
 #include "squashfs_fs.h"
@@ -42,6 +43,10 @@
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
 
+
+#define SQUASHFS_CRYPTO_ALG	"deflate"
+
+
 static struct file_system_type squashfs_fs_type;
 static struct super_operations squashfs_super_ops;
 
@@ -75,6 +80,7 @@ static int squashfs_fill_super(struct su
 	unsigned short flags;
 	unsigned int fragments;
 	long long lookup_table_start;
+	struct deflate_comp_params params;
 	int err;
 
 	TRACE("Entered squashfs_fill_superblock\n");
@@ -86,15 +92,28 @@ static int squashfs_fill_super(struct su
 	}
 	msblk = sb->s_fs_info;
 
-	msblk->stream.workspace = vmalloc(zlib_inflate_workspacesize());
-	if (msblk->stream.workspace == NULL) {
-		ERROR("Failed to allocate zlib workspace\n");
+	msblk->tfm = crypto_alloc_pcomp(SQUASHFS_CRYPTO_ALG, 0,
+					CRYPTO_ALG_ASYNC);
+	if (IS_ERR(msblk->tfm)) {
+		ERROR("Failed to load %s crypto module\n", SQUASHFS_CRYPTO_ALG);
+		msblk->tfm = NULL;
+		err = -ENOMEM;
+		goto failure;
+	}
+
+	params.enable_comp = 0;
+	params.enable_decomp = 1;
+	params.windowBits = DEF_WBITS;
+	err = crypto_pcomp_setup(msblk->tfm, &params);
+	if (err) {
+		ERROR("Failed to set up decompression parameters\n");
 		goto failure;
 	}
 
 	sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
 	if (sblk == NULL) {
 		ERROR("Failed to allocate squashfs_super_block\n");
+		err = -ENOMEM;
 		goto failure;
 	}
 
@@ -284,17 +303,17 @@ failed_mount:
 	kfree(msblk->inode_lookup_table);
 	kfree(msblk->fragment_index);
 	kfree(msblk->id_table);
-	vfree(msblk->stream.workspace);
+	crypto_free_pcomp(msblk->tfm);
 	kfree(sb->s_fs_info);
 	sb->s_fs_info = NULL;
 	kfree(sblk);
 	return err;
 
 failure:
-	vfree(msblk->stream.workspace);
+	crypto_free_pcomp(msblk->tfm);
 	kfree(sb->s_fs_info);
 	sb->s_fs_info = NULL;
-	return -ENOMEM;
+	return err;
 }
 
 
@@ -333,7 +352,7 @@ static void squashfs_put_super(struct su
 		kfree(sbi->id_table);
 		kfree(sbi->fragment_index);
 		kfree(sbi->meta_index);
-		vfree(sbi->stream.workspace);
+		crypto_free_pcomp(sbi->tfm);
 		kfree(sb->s_fs_info);
 		sb->s_fs_info = NULL;
 	}

-- 
With kind regards,

Geert Uytterhoeven
Software Architect

Sony Techsoft Centre Europe
The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium

Phone:    +32 (0)2 700 8453
Fax:      +32 (0)2 700 8622
E-mail:   Geert.Uytterhoeven@xxxxxxxxxxx
Internet: http://www.sony-europe.com/

A division of Sony Europe (Belgium) N.V.
VAT BE 0413.825.160 · RPR Brussels
Fortis · BIC GEBABEBB · IBAN BE41293037680010

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