From: Geert Uytterhoeven <[EMAIL PROTECTED]>

Modify SquashFS 3.4 to use the "zlib" crypto module instead of making direct
calls to the zlib/inflate library

Signed-off-by: Geert Uytterhoeven <[EMAIL PROTECTED]>
---
 fs/Kconfig                     |    3 +
 fs/squashfs/inode.c            |   65 +++++++++++++++++++++--------------------
 include/linux/squashfs_fs_sb.h |    3 +
 3 files changed, 38 insertions(+), 33 deletions(-)

--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -1350,7 +1350,8 @@ config CRAMFS
 
 config SQUASHFS
        tristate "SquashFS 3.4 - Squashed file system support"
-       select ZLIB_INFLATE
+       select CRYPTO
+       select CRYPTO_ZLIB
        help
          Saying Y here includes support for SquashFS 3.4 (a Compressed
          Read-Only File System).  Squashfs is a highly compressed read-only
--- a/fs/squashfs/inode.c
+++ b/fs/squashfs/inode.c
@@ -23,7 +23,6 @@
 
 #include <linux/squashfs_fs.h>
 #include <linux/module.h>
-#include <linux/zlib.h>
 #include <linux/fs.h>
 #include <linux/squashfs_fs_sb.h>
 #include <linux/squashfs_fs_i.h>
@@ -36,6 +35,9 @@
 
 #include "squashfs.h"
 
+#define SQUASHFS_CRYPTO_ALG    "zlib"
+
+
 static struct dentry *squashfs_fh_to_dentry(struct super_block *s,
                struct fid *fid, int fh_len, int fh_type);
 static struct dentry *squashfs_fh_to_parent(struct super_block *s,
@@ -236,7 +238,10 @@ SQSH_EXTERN unsigned int squashfs_read_d
        }
 
        if (compressed) {
-               int zlib_err = 0;
+               int error = 0;
+               void *next_out;
+               int avail_out;
+               unsigned int total_out = 0, dlen;
 
                /*
                * uncompress block
@@ -244,8 +249,8 @@ SQSH_EXTERN unsigned int squashfs_read_d
 
                mutex_lock(&msblk->read_data_mutex);
 
-               msblk->stream.next_out = buffer;
-               msblk->stream.avail_out = srclength;
+               next_out = buffer;
+               avail_out = srclength;
 
                for (bytes = 0; k < b; k++) {
                        avail_bytes = min(c_byte - bytes, msblk->devblksize - 
offset);
@@ -254,16 +259,8 @@ SQSH_EXTERN unsigned int squashfs_read_d
                        if (!buffer_uptodate(bh[k]))
                                goto release_mutex;
 
-                       msblk->stream.next_in = bh[k]->b_data + offset;
-                       msblk->stream.avail_in = avail_bytes;
-
                        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);
-                                       goto release_mutex;
-                               }
+                               total_out = 0;
 
                                if (avail_bytes == 0) {
                                        offset = 0;
@@ -272,29 +269,32 @@ SQSH_EXTERN unsigned int squashfs_read_d
                                }
                        }
 
-                       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);
+                       dlen = avail_out;
+                       error = crypto_comp_decompress(msblk->tfm,
+                                                      bh[k]->b_data + offset,
+                                                      avail_bytes, next_out,
+                                                      &dlen);
+                       if (error && error != -EAGAIN) {
+                               ERROR("crypto_comp_decompress returned "
+                                     "unexpected result %d, srclength %d, "
+                                     "avail_bytes %d, avail_out %d\n",
+                                     error, srclength, avail_bytes,
+                                     avail_out);
                                goto release_mutex;
                        }
+                       next_out += dlen;
+                       avail_out -= dlen;
+                       total_out += dlen;
 
                        bytes += avail_bytes;
                        offset = 0;
                        brelse(bh[k]);
                }
 
-               if (zlib_err != Z_STREAM_END)
+               if (error)
                        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);
-                       goto release_mutex;
-               }
-               bytes = msblk->stream.total_out;
+               bytes = total_out;
                mutex_unlock(&msblk->read_data_mutex);
        } else {
                int i;
@@ -1104,9 +1104,12 @@ static int squashfs_fill_super(struct su
        }
        msblk = s->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_comp(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;
                goto failure;
        }
        sblk = &msblk->sblk;
@@ -1273,7 +1276,7 @@ failed_mount:
        vfree(msblk->read_page);
        squashfs_cache_delete(msblk->block_cache);
        kfree(msblk->fragment_index_2);
-       vfree(msblk->stream.workspace);
+       crypto_free_comp(msblk->tfm);
        kfree(s->s_fs_info);
        s->s_fs_info = NULL;
        return -EINVAL;
@@ -2084,7 +2087,7 @@ static void squashfs_put_super(struct su
                kfree(sbi->fragment_index);
                kfree(sbi->fragment_index_2);
                kfree(sbi->meta_index);
-               vfree(sbi->stream.workspace);
+               crypto_free_comp(sbi->tfm);
                kfree(s->s_fs_info);
                s->s_fs_info = NULL;
        }
--- a/include/linux/squashfs_fs_sb.h
+++ b/include/linux/squashfs_fs_sb.h
@@ -24,6 +24,7 @@
  */
 
 #include <linux/squashfs_fs.h>
+#include <linux/crypto.h>
 
 struct squashfs_cache_entry {
        long long       block;
@@ -67,7 +68,7 @@ struct squashfs_sb_info {
        struct mutex            read_page_mutex;
        struct mutex            meta_index_mutex;
        struct meta_index       *meta_index;
-       z_stream                stream;
+       struct crypto_comp      *tfm;
        long long               *inode_lookup_table;
        int                     (*read_inode)(struct inode *i,  
squashfs_inode_t \
                                inode);

-- 
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:   [EMAIL PROTECTED]
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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