Modify SquashFS 4 to use the new "zlib" crypto module as a proof-of-concept for
the partial decompression CRYPTO API enhancements.
Note: Patch against squashfs-2.6.git, as SquashFS is not yet in mainline
Signed-off-by: Geert Uytterhoeven <[EMAIL PROTECTED]>
---
Kconfig | 3 +-
squashfs/block.c | 67 +++++++++++++++++++++++++++-------------------
squashfs/squashfs_fs_sb.h | 4 ++
squashfs/super.c | 20 ++++++++-----
4 files changed, 58 insertions(+), 36 deletions(-)
diff --git a/fs/Kconfig b/fs/Kconfig
index 1d7a5f9..8eebe53 100644
--- 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_ZLIB
help
Saying Y here includes support for SquashFS 4.0 (a Compressed
Read-Only File System). Squashfs is a highly compressed read-only
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index da5f88b..9a681cb 100644
--- 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_block *sb, void *buffer,
}
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_block *sb, void *buffer,
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_block *sb, void
*buffer,
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_comp_decompress_init(msblk->tfm,
+ &req);
+ if (error && error != -EAGAIN) {
+ ERROR("crypto_comp_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_block *sb, void
*buffer,
brelse(bh[k]);
continue;
}
+
+ } else {
+ error =
crypto_comp_decompress_update(msblk->tfm,
+ &req);
+ if (error) {
+ ERROR("crypto_comp_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_comp_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_block *sb, void
*buffer,
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_comp_decompress_final(msblk->tfm, &req);
+ if (error) {
+ ERROR("crypto_comp_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 {
/*
diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h
index 18e5af4..769bbef 100644
--- a/fs/squashfs/squashfs_fs_sb.h
+++ b/fs/squashfs/squashfs_fs_sb.h
@@ -23,6 +23,8 @@
* squashfs_fs_sb.h
*/
+#include <linux/crypto.h>
+
#include "squashfs_fs.h"
struct squashfs_cache_entry {
@@ -63,7 +65,7 @@ struct squashfs_sb_info {
struct mutex read_data_mutex;
struct mutex meta_index_mutex;
struct meta_index *meta_index;
- z_stream stream;
+ struct crypto_comp *tfm;
__le64 *inode_lookup_table;
long long inode_table;
long long directory_table;
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 44f94aa..38e0535 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -35,13 +35,17 @@
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/module.h>
-#include <linux/zlib.h>
+#include <linux/crypto.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs_fs_i.h"
#include "squashfs.h"
+
+#define SQUASHFS_CRYPTO_ALG "zlib"
+
+
static struct file_system_type squashfs_fs_type;
static struct super_operations squashfs_super_ops;
@@ -86,9 +90,11 @@ static int squashfs_fill_super(struct super_block *sb, void
*data, int silent)
}
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_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;
}
@@ -284,14 +290,14 @@ failed_mount:
kfree(msblk->inode_lookup_table);
kfree(msblk->fragment_index);
kfree(msblk->id_table);
- vfree(msblk->stream.workspace);
+ crypto_free_comp(msblk->tfm);
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;
kfree(sblk);
return err;
failure:
- vfree(msblk->stream.workspace);
+ crypto_free_comp(msblk->tfm);
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;
return -ENOMEM;
@@ -333,7 +339,7 @@ static void squashfs_put_super(struct super_block *sb)
kfree(sbi->id_table);
kfree(sbi->fragment_index);
kfree(sbi->meta_index);
- vfree(sbi->stream.workspace);
+ crypto_free_comp(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: [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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