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authorLinus Torvalds <torvalds@linux-foundation.org>2010-03-05 10:46:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2010-03-05 10:46:04 -0800
commitb24bc1e61cec2174faf5dfa632da16b6ca17144f (patch)
tree33abe2345c70d4bce31cda8fe2e562a8a9a24dfc /fs
parent64ba9926759792cf7b95f823402e2781edd1b5d4 (diff)
parent06862f884d9c2453daaf0c1d070c69cf444f10b1 (diff)
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Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus: Squashfs: get rid of obsolete definition in header file Squashfs: get rid of obsolete variable in struct squashfs_sb_info Squashfs: add decompressor entries for lzma and lzo Squashfs: add a decompressor framework Squashfs: factor out remaining zlib dependencies into separate wrapper file Squashfs: move zlib decompression wrapper code into a separate file
Diffstat (limited to 'fs')
-rw-r--r--fs/squashfs/Makefile2
-rw-r--r--fs/squashfs/block.c76
-rw-r--r--fs/squashfs/cache.c1
-rw-r--r--fs/squashfs/decompressor.c68
-rw-r--r--fs/squashfs/decompressor.h55
-rw-r--r--fs/squashfs/dir.c1
-rw-r--r--fs/squashfs/export.c1
-rw-r--r--fs/squashfs/file.c1
-rw-r--r--fs/squashfs/fragment.c1
-rw-r--r--fs/squashfs/id.c1
-rw-r--r--fs/squashfs/inode.c1
-rw-r--r--fs/squashfs/namei.c1
-rw-r--r--fs/squashfs/squashfs.h8
-rw-r--r--fs/squashfs/squashfs_fs.h6
-rw-r--r--fs/squashfs/squashfs_fs_sb.h40
-rw-r--r--fs/squashfs/super.c49
-rw-r--r--fs/squashfs/symlink.c1
-rw-r--r--fs/squashfs/zlib_wrapper.c150
18 files changed, 335 insertions, 128 deletions
diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile
index 70e3244fa30..df8a19ef870 100644
--- a/fs/squashfs/Makefile
+++ b/fs/squashfs/Makefile
@@ -4,4 +4,4 @@
obj-$(CONFIG_SQUASHFS) += squashfs.o
squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
-squashfs-y += namei.o super.o symlink.o
+squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 2a796031034..1cb0d81b164 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -29,15 +29,14 @@
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/slab.h>
-#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
-#include <linux/zlib.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs_fs_i.h"
#include "squashfs.h"
+#include "decompressor.h"
/*
* Read the metadata block length, this is stored in the first two
@@ -153,72 +152,10 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
}
if (compressed) {
- int zlib_err = 0, zlib_init = 0;
-
- /*
- * Uncompress block.
- */
-
- mutex_lock(&msblk->read_data_mutex);
-
- msblk->stream.avail_out = 0;
- msblk->stream.avail_in = 0;
-
- bytes = length;
- do {
- if (msblk->stream.avail_in == 0 && k < b) {
- avail = min(bytes, msblk->devblksize - offset);
- bytes -= avail;
- wait_on_buffer(bh[k]);
- if (!buffer_uptodate(bh[k]))
- goto release_mutex;
-
- if (avail == 0) {
- offset = 0;
- put_bh(bh[k++]);
- continue;
- }
-
- msblk->stream.next_in = bh[k]->b_data + offset;
- msblk->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 (!zlib_init) {
- 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;
- }
- zlib_init = 1;
- }
-
- zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH);
-
- if (msblk->stream.avail_in == 0 && k < b)
- put_bh(bh[k++]);
- } while (zlib_err == Z_OK);
-
- if (zlib_err != Z_STREAM_END) {
- ERROR("zlib_inflate error, data probably corrupt\n");
- goto release_mutex;
- }
-
- zlib_err = zlib_inflateEnd(&msblk->stream);
- if (zlib_err != Z_OK) {
- ERROR("zlib_inflate error, data probably corrupt\n");
- goto release_mutex;
- }
- length = msblk->stream.total_out;
- mutex_unlock(&msblk->read_data_mutex);
+ length = squashfs_decompress(msblk, buffer, bh, b, offset,
+ length, srclength, pages);
+ if (length < 0)
+ goto read_failure;
} else {
/*
* Block is uncompressed.
@@ -255,9 +192,6 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
kfree(bh);
return length;
-release_mutex:
- mutex_unlock(&msblk->read_data_mutex);
-
block_release:
for (; k < b; k++)
put_bh(bh[k]);
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c
index 40c98fa6b5d..57314bee905 100644
--- a/fs/squashfs/cache.c
+++ b/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"
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
new file mode 100644
index 00000000000..157478da6ac
--- /dev/null
+++ b/fs/squashfs/decompressor.c
@@ -0,0 +1,68 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ * Phillip Lougher <phillip@lougher.demon.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * decompressor.c
+ */
+
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "decompressor.h"
+#include "squashfs.h"
+
+/*
+ * This file (and decompressor.h) implements a decompressor framework for
+ * Squashfs, allowing multiple decompressors to be easily supported
+ */
+
+static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
+ NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
+};
+
+static const struct squashfs_decompressor squashfs_lzo_unsupported_comp_ops = {
+ NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
+};
+
+static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
+ NULL, NULL, NULL, 0, "unknown", 0
+};
+
+static const struct squashfs_decompressor *decompressor[] = {
+ &squashfs_zlib_comp_ops,
+ &squashfs_lzma_unsupported_comp_ops,
+ &squashfs_lzo_unsupported_comp_ops,
+ &squashfs_unknown_comp_ops
+};
+
+
+const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
+{
+ int i;
+
+ for (i = 0; decompressor[i]->id; i++)
+ if (id == decompressor[i]->id)
+ break;
+
+ return decompressor[i];
+}
diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h
new file mode 100644
index 00000000000..7425f80783f
--- /dev/null
+++ b/fs/squashfs/decompressor.h
@@ -0,0 +1,55 @@
+#ifndef DECOMPRESSOR_H
+#define DECOMPRESSOR_H
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ * Phillip Lougher <phillip@lougher.demon.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * decompressor.h
+ */
+
+struct squashfs_decompressor {
+ void *(*init)(struct squashfs_sb_info *);
+ void (*free)(void *);
+ int (*decompress)(struct squashfs_sb_info *, void **,
+ struct buffer_head **, int, int, int, int, int);
+ int id;
+ char *name;
+ 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)
+{
+ if (msblk->decompressor)
+ msblk->decompressor->free(s);
+}
+
+static inline int squashfs_decompress(struct squashfs_sb_info *msblk,
+ void **buffer, struct buffer_head **bh, int b, int offset, int length,
+ int srclength, int pages)
+{
+ return msblk->decompressor->decompress(msblk, buffer, bh, b, offset,
+ length, srclength, pages);
+}
+#endif
diff --git a/fs/squashfs/dir.c b/fs/squashfs/dir.c
index 566b0eaed86..12b933ac658 100644
--- a/fs/squashfs/dir.c
+++ b/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"
diff --git a/fs/squashfs/export.c b/fs/squashfs/export.c
index 2b1b8fe5e03..7f93d5a9ee0 100644
--- a/fs/squashfs/export.c
+++ b/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"
diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
index 717767d831d..a25c5060bdc 100644
--- a/fs/squashfs/file.c
+++ b/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"
diff --git a/fs/squashfs/fragment.c b/fs/squashfs/fragment.c
index b5a2c15bbbc..7c90bbd6879 100644
--- a/fs/squashfs/fragment.c
+++ b/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"
diff --git a/fs/squashfs/id.c b/fs/squashfs/id.c
index 3795b837ba2..b7f64bcd2b7 100644
--- a/fs/squashfs/id.c
+++ b/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"
diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c
index 9101dbde39e..49daaf669e4 100644
--- a/fs/squashfs/inode.c
+++ b/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"
diff --git a/fs/squashfs/namei.c b/fs/squashfs/namei.c
index 9e398653b22..5266bd8ad93 100644
--- a/fs/squashfs/namei.c
+++ b/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"
diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h
index 0e9feb6adf7..fe2587af551 100644
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -51,6 +51,9 @@ extern struct squashfs_cache_entry *squashfs_get_datablock(struct super_block *,
u64, int);
extern int squashfs_read_table(struct super_block *, void *, u64, int);
+/* decompressor.c */
+extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int);
+
/* export.c */
extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64,
unsigned int);
@@ -71,7 +74,7 @@ extern struct inode *squashfs_iget(struct super_block *, long long,
extern int squashfs_read_inode(struct inode *, long long);
/*
- * Inodes and files operations
+ * Inodes, files and decompressor operations
*/
/* dir.c */
@@ -88,3 +91,6 @@ extern const struct inode_operations squashfs_dir_inode_ops;
/* symlink.c */
extern const struct address_space_operations squashfs_symlink_aops;
+
+/* zlib_wrapper.c */
+extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h
index 283daafc568..79024245ea0 100644
--- a/fs/squashfs/squashfs_fs.h
+++ b/fs/squashfs/squashfs_fs.h
@@ -183,8 +183,6 @@
#define SQUASHFS_MAX_FILE_SIZE (1LL << \
(SQUASHFS_MAX_FILE_SIZE_LOG - 2))
-#define SQUASHFS_MARKER_BYTE 0xff
-
/* meta index cache */
#define SQUASHFS_META_INDEXES (SQUASHFS_METADATA_SIZE / sizeof(unsigned int))
#define SQUASHFS_META_ENTRIES 127
@@ -211,7 +209,9 @@ struct meta_index {
/*
* definitions for structures on disk
*/
-#define ZLIB_COMPRESSION 1
+#define ZLIB_COMPRESSION 1
+#define LZMA_COMPRESSION 2
+#define LZO_COMPRESSION 3
struct squashfs_super_block {
__le32 s_magic;
diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h
index c8c65614dd1..2e77dc547e2 100644
--- a/fs/squashfs/squashfs_fs_sb.h
+++ b/fs/squashfs/squashfs_fs_sb.h
@@ -52,25 +52,25 @@ struct squashfs_cache_entry {
};
struct squashfs_sb_info {
- int devblksize;
- int devblksize_log2;
- struct squashfs_cache *block_cache;
- struct squashfs_cache *fragment_cache;
- struct squashfs_cache *read_page;
- int next_meta_index;
- __le64 *id_table;
- __le64 *fragment_index;
- unsigned int *fragment_index_2;
- struct mutex read_data_mutex;
- struct mutex meta_index_mutex;
- struct meta_index *meta_index;
- z_stream stream;
- __le64 *inode_lookup_table;
- u64 inode_table;
- u64 directory_table;
- unsigned int block_size;
- unsigned short block_log;
- long long bytes_used;
- unsigned int inodes;
+ const struct squashfs_decompressor *decompressor;
+ int devblksize;
+ int devblksize_log2;
+ struct squashfs_cache *block_cache;
+ struct squashfs_cache *fragment_cache;
+ struct squashfs_cache *read_page;
+ int next_meta_index;
+ __le64 *id_table;
+ __le64 *fragment_index;
+ struct mutex read_data_mutex;
+ struct mutex meta_index_mutex;
+ struct meta_index *meta_index;
+ void *stream;
+ __le64 *inode_lookup_table;
+ u64 inode_table;
+ u64 directory_table;
+ unsigned int block_size;
+ unsigned short block_log;
+ long long bytes_used;
+ unsigned int inodes;
};
#endif
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 6c197ef53ad..3550aec2f65 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -35,34 +35,41 @@
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/module.h>
-#include <linux/zlib.h>
#include <linux/magic.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs_fs_i.h"
#include "squashfs.h"
+#include "decompressor.h"
static struct file_system_type squashfs_fs_type;
static const struct super_operations squashfs_super_ops;
-static int supported_squashfs_filesystem(short major, short minor, short comp)
+static const struct squashfs_decompressor *supported_squashfs_filesystem(short
+ major, short minor, short id)
{
+ const struct squashfs_decompressor *decompressor;
+
if (major < SQUASHFS_MAJOR) {
ERROR("Major/Minor mismatch, older Squashfs %d.%d "
"filesystems are unsupported\n", major, minor);
- return -EINVAL;
+ return NULL;
} else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
ERROR("Major/Minor mismatch, trying to mount newer "
"%d.%d filesystem\n", major, minor);
ERROR("Please update your kernel\n");
- return -EINVAL;
+ return NULL;
}
- if (comp != ZLIB_COMPRESSION)
- return -EINVAL;
+ decompressor = squashfs_lookup_decompressor(id);
+ if (!decompressor->supported) {
+ ERROR("Filesystem uses \"%s\" compression. This is not "
+ "supported\n", decompressor->name);
+ return NULL;
+ }
- return 0;
+ return decompressor;
}
@@ -87,13 +94,6 @@ 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");
- goto failure;
- }
-
sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
if (sblk == NULL) {
ERROR("Failed to allocate squashfs_super_block\n");
@@ -120,25 +120,25 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
goto failed_mount;
}
+ err = -EINVAL;
+
/* Check it is a SQUASHFS superblock */
sb->s_magic = le32_to_cpu(sblk->s_magic);
if (sb->s_magic != SQUASHFS_MAGIC) {
if (!silent)
ERROR("Can't find a SQUASHFS superblock on %s\n",
bdevname(sb->s_bdev, b));
- err = -EINVAL;
goto failed_mount;
}
- /* Check the MAJOR & MINOR versions and compression type */
- err = supported_squashfs_filesystem(le16_to_cpu(sblk->s_major),
+ /* Check the MAJOR & MINOR versions and lookup compression type */
+ msblk->decompressor = supported_squashfs_filesystem(
+ le16_to_cpu(sblk->s_major),
le16_to_cpu(sblk->s_minor),
le16_to_cpu(sblk->compression));
- if (err < 0)
+ if (msblk->decompressor == NULL)
goto failed_mount;
- err = -EINVAL;
-
/*
* Check if there's xattrs in the filesystem. These are not
* supported in this version, so warn that they will be ignored.
@@ -205,6 +205,10 @@ 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)
@@ -292,17 +296,16 @@ failed_mount:
squashfs_cache_delete(msblk->block_cache);
squashfs_cache_delete(msblk->fragment_cache);
squashfs_cache_delete(msblk->read_page);
+ squashfs_decompressor_free(msblk, 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);
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;
return -ENOMEM;
@@ -346,10 +349,10 @@ 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_decompressor_free(sbi, 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;
}
diff --git a/fs/squashfs/symlink.c b/fs/squashfs/symlink.c
index 83d87880aac..e80be2022a7 100644
--- a/fs/squashfs/symlink.c
+++ b/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"
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
new file mode 100644
index 00000000000..4dd70e04333
--- /dev/null
+++ b/fs/squashfs/zlib_wrapper.c
@@ -0,0 +1,150 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ * Phillip Lougher <phillip@lougher.demon.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * zlib_wrapper.c
+ */
+
+
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+#include <linux/zlib.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+#include "decompressor.h"
+
+static void *zlib_init(struct squashfs_sb_info *dummy)
+{
+ 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;
+}
+
+
+static void zlib_free(void *strm)
+{
+ z_stream *stream = strm;
+
+ if (stream)
+ kfree(stream->workspace);
+ kfree(stream);
+}
+
+
+static int 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);
+
+ stream->avail_out = 0;
+ stream->avail_in = 0;
+
+ bytes = length;
+ do {
+ if (stream->avail_in == 0 && k < b) {
+ avail = min(bytes, msblk->devblksize - offset);
+ bytes -= avail;
+ wait_on_buffer(bh[k]);
+ if (!buffer_uptodate(bh[k]))
+ goto release_mutex;
+
+ if (avail == 0) {
+ offset = 0;
+ put_bh(bh[k++]);
+ continue;
+ }
+
+ stream->next_in = bh[k]->b_data + offset;
+ stream->avail_in = avail;
+ offset = 0;
+ }
+
+ 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(stream);
+ if (zlib_err != Z_OK) {
+ ERROR("zlib_inflateInit returned unexpected "
+ "result 0x%x, srclength %d\n",
+ zlib_err, srclength);
+ goto release_mutex;
+ }
+ zlib_init = 1;
+ }
+
+ zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
+
+ if (stream->avail_in == 0 && k < b)
+ put_bh(bh[k++]);
+ } while (zlib_err == Z_OK);
+
+ if (zlib_err != Z_STREAM_END) {
+ ERROR("zlib_inflate error, data probably corrupt\n");
+ goto release_mutex;
+ }
+
+ 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 stream->total_out;
+
+release_mutex:
+ mutex_unlock(&msblk->read_data_mutex);
+
+ for (; k < b; k++)
+ put_bh(bh[k]);
+
+ return -EIO;
+}
+
+const struct squashfs_decompressor squashfs_zlib_comp_ops = {
+ .init = zlib_init,
+ .free = zlib_free,
+ .decompress = zlib_uncompress,
+ .id = ZLIB_COMPRESSION,
+ .name = "zlib",
+ .supported = 1
+};
+