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authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-24 08:02:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-24 08:02:21 -0700
commit5818fcc8bd1b27af4d40b8357b91a56cc3fae6a4 (patch)
treec2f266e82306fa98c78130b0dc79ef9716d3c9c7
parent0625bef6060fab4aab0e484130b59af5e9ac81bc (diff)
parent117a91e0f25fd7698e20ac3dfa62086be3dc82a3 (diff)
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: Use vmalloc rather than kmalloc for zlib workspace Squashfs: handle corruption of directory structure Squashfs: wrap squashfs_mount() definition Squashfs: xz_wrapper doesn't need to include squashfs_fs_i.h anymore Squashfs: Update documentation to include compression options Squashfs: Update Kconfig help text to include xz compression Squashfs: add compression options support to xz decompressor Squashfs: extend decompressor framework to handle compression options
-rw-r--r--Documentation/filesystems/squashfs.txt28
-rw-r--r--fs/squashfs/Kconfig12
-rw-r--r--fs/squashfs/decompressor.c34
-rw-r--r--fs/squashfs/decompressor.h7
-rw-r--r--fs/squashfs/dir.c9
-rw-r--r--fs/squashfs/lzo_wrapper.c4
-rw-r--r--fs/squashfs/namei.c12
-rw-r--r--fs/squashfs/squashfs.h1
-rw-r--r--fs/squashfs/squashfs_fs.h4
-rw-r--r--fs/squashfs/super.c15
-rw-r--r--fs/squashfs/xz_wrapper.c53
-rw-r--r--fs/squashfs/zlib_wrapper.c10
12 files changed, 145 insertions, 44 deletions
diff --git a/Documentation/filesystems/squashfs.txt b/Documentation/filesystems/squashfs.txt
index 66699afd66ca..2d78f1911844 100644
--- a/Documentation/filesystems/squashfs.txt
+++ b/Documentation/filesystems/squashfs.txt
@@ -59,12 +59,15 @@ obtained from this site also.
3. SQUASHFS FILESYSTEM DESIGN
-----------------------------
-A squashfs filesystem consists of a maximum of eight parts, packed together on a byte
-alignment:
+A squashfs filesystem consists of a maximum of nine parts, packed together on a
+byte alignment:
---------------
| superblock |
|---------------|
+ | compression |
+ | options |
+ |---------------|
| datablocks |
| & fragments |
|---------------|
@@ -91,7 +94,14 @@ the source directory, and checked for duplicates. Once all file data has been
written the completed inode, directory, fragment, export and uid/gid lookup
tables are written.
-3.1 Inodes
+3.1 Compression options
+-----------------------
+
+Compressors can optionally support compression specific options (e.g.
+dictionary size). If non-default compression options have been used, then
+these are stored here.
+
+3.2 Inodes
----------
Metadata (inodes and directories) are compressed in 8Kbyte blocks. Each
@@ -114,7 +124,7 @@ directory inode are defined: inodes optimised for frequently occurring
regular files and directories, and extended types where extra
information has to be stored.
-3.2 Directories
+3.3 Directories
---------------
Like inodes, directories are packed into compressed metadata blocks, stored
@@ -144,7 +154,7 @@ decompressed to do a lookup irrespective of the length of the directory.
This scheme has the advantage that it doesn't require extra memory overhead
and doesn't require much extra storage on disk.
-3.3 File data
+3.4 File data
-------------
Regular files consist of a sequence of contiguous compressed blocks, and/or a
@@ -163,7 +173,7 @@ Larger files use multiple slots, with 1.75 TiB files using all 8 slots.
The index cache is designed to be memory efficient, and by default uses
16 KiB.
-3.4 Fragment lookup table
+3.5 Fragment lookup table
-------------------------
Regular files can contain a fragment index which is mapped to a fragment
@@ -173,7 +183,7 @@ A second index table is used to locate these. This second index table for
speed of access (and because it is small) is read at mount time and cached
in memory.
-3.5 Uid/gid lookup table
+3.6 Uid/gid lookup table
------------------------
For space efficiency regular files store uid and gid indexes, which are
@@ -182,7 +192,7 @@ stored compressed into metadata blocks. A second index table is used to
locate these. This second index table for speed of access (and because it
is small) is read at mount time and cached in memory.
-3.6 Export table
+3.7 Export table
----------------
To enable Squashfs filesystems to be exportable (via NFS etc.) filesystems
@@ -196,7 +206,7 @@ This table is stored compressed into metadata blocks. A second index table is
used to locate these. This second index table for speed of access (and because
it is small) is read at mount time and cached in memory.
-3.7 Xattr table
+3.8 Xattr table
---------------
The xattr table contains extended attributes for each inode. The xattrs
diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
index aa68a8a31518..efc309fa3035 100644
--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -5,12 +5,12 @@ config SQUASHFS
help
Saying Y here includes support for SquashFS 4.0 (a Compressed
Read-Only File System). Squashfs is a highly compressed read-only
- filesystem for Linux. It uses zlib/lzo compression to compress both
- files, inodes and directories. Inodes in the system are very small
- and all blocks are packed to minimise data overhead. Block sizes
- greater than 4K are supported up to a maximum of 1 Mbytes (default
- block size 128K). SquashFS 4.0 supports 64 bit filesystems and files
- (larger than 4GB), full uid/gid information, hard links and
+ filesystem for Linux. It uses zlib, lzo or xz compression to
+ compress both files, inodes and directories. Inodes in the system
+ are very small and all blocks are packed to minimise data overhead.
+ Block sizes greater than 4K are supported up to a maximum of 1 Mbytes
+ (default block size 128K). SquashFS 4.0 supports 64 bit filesystems
+ and files (larger than 4GB), full uid/gid information, hard links and
timestamps.
Squashfs is intended for general read-only filesystem use, for
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index a5940e54c4dd..e921bd213738 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 3b305a70f7aa..099745ad5691 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/dir.c b/fs/squashfs/dir.c
index 0dc340aa2be9..3f79cd1d0c19 100644
--- a/fs/squashfs/dir.c
+++ b/fs/squashfs/dir.c
@@ -172,6 +172,11 @@ static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir)
length += sizeof(dirh);
dir_count = le32_to_cpu(dirh.count) + 1;
+
+ /* dir_count should never be larger than 256 */
+ if (dir_count > 256)
+ goto failed_read;
+
while (dir_count--) {
/*
* Read directory entry.
@@ -183,6 +188,10 @@ static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir)
size = le16_to_cpu(dire->size) + 1;
+ /* size should never be larger than SQUASHFS_NAME_LEN */
+ if (size > SQUASHFS_NAME_LEN)
+ goto failed_read;
+
err = squashfs_read_metadata(inode->i_sb, dire->name,
&block, &offset, size);
if (err < 0)
diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
index 7da759e34c52..00f4dfc5f088 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/namei.c b/fs/squashfs/namei.c
index 7a9464d08cf6..5d922a6701ab 100644
--- a/fs/squashfs/namei.c
+++ b/fs/squashfs/namei.c
@@ -176,6 +176,11 @@ static struct dentry *squashfs_lookup(struct inode *dir, struct dentry *dentry,
length += sizeof(dirh);
dir_count = le32_to_cpu(dirh.count) + 1;
+
+ /* dir_count should never be larger than 256 */
+ if (dir_count > 256)
+ goto data_error;
+
while (dir_count--) {
/*
* Read directory entry.
@@ -187,6 +192,10 @@ static struct dentry *squashfs_lookup(struct inode *dir, struct dentry *dentry,
size = le16_to_cpu(dire->size) + 1;
+ /* size should never be larger than SQUASHFS_NAME_LEN */
+ if (size > SQUASHFS_NAME_LEN)
+ goto data_error;
+
err = squashfs_read_metadata(dir->i_sb, dire->name,
&block, &offset, size);
if (err < 0)
@@ -228,6 +237,9 @@ exit_lookup:
d_add(dentry, inode);
return ERR_PTR(0);
+data_error:
+ err = -EIO;
+
read_failure:
ERROR("Unable to read directory block [%llx:%x]\n",
squashfs_i(dir)->start + msblk->directory_table,
diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h
index ba729d808876..1f2e608b8785 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 39533feffd6d..4582c568ef4d 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 20700b9f2b4c..5c8184c061a4 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));
@@ -370,8 +373,8 @@ static void squashfs_put_super(struct super_block *sb)
}
-static struct dentry *squashfs_mount(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data)
+static struct dentry *squashfs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, squashfs_fill_super);
}
diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c
index c4eb40018256..aa47a286d1f8 100644
--- a/fs/squashfs/xz_wrapper.c
+++ b/fs/squashfs/xz_wrapper.c
@@ -26,10 +26,10 @@
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/xz.h>
+#include <linux/bitops.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
#include "squashfs.h"
#include "decompressor.h"
@@ -38,24 +38,57 @@ struct squashfs_xz {
struct xz_buf buf;
};
-static void *squashfs_xz_init(struct squashfs_sb_info *msblk)
+struct comp_opts {
+ __le32 dictionary_size;
+ __le32 flags;
+};
+
+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);
+ struct comp_opts *comp_opts = buff;
+ struct squashfs_xz *stream;
+ int dict_size = msblk->block_size;
+ int err, n;
+
+ if (comp_opts) {
+ /* check compressor options are the expected length */
+ if (len < sizeof(*comp_opts)) {
+ err = -EIO;
+ goto failed;
+ }
- struct squashfs_xz *stream = kmalloc(sizeof(*stream), GFP_KERNEL);
- if (stream == NULL)
+ dict_size = le32_to_cpu(comp_opts->dictionary_size);
+
+ /* the dictionary size should be 2^n or 2^n+2^(n+1) */
+ n = ffs(dict_size) - 1;
+ if (dict_size != (1 << n) && dict_size != (1 << n) +
+ (1 << (n + 1))) {
+ err = -EIO;
+ goto failed;
+ }
+ }
+
+ dict_size = max_t(int, dict_size, SQUASHFS_METADATA_SIZE);
+
+ stream = kmalloc(sizeof(*stream), GFP_KERNEL);
+ if (stream == NULL) {
+ err = -ENOMEM;
goto failed;
+ }
- stream->state = xz_dec_init(XZ_PREALLOC, block_size);
- if (stream->state == NULL)
+ stream->state = xz_dec_init(XZ_PREALLOC, dict_size);
+ if (stream->state == NULL) {
+ kfree(stream);
+ err = -ENOMEM;
goto failed;
+ }
return stream;
failed:
- ERROR("Failed to allocate xz workspace\n");
- kfree(stream);
- return NULL;
+ ERROR("Failed to initialise xz decompressor\n");
+ return ERR_PTR(err);
}
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 4661ae2b1cec..517688b32ffa 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -26,19 +26,19 @@
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/zlib.h>
+#include <linux/vmalloc.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#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)
goto failed;
- stream->workspace = kmalloc(zlib_inflate_workspacesize(),
- GFP_KERNEL);
+ stream->workspace = vmalloc(zlib_inflate_workspacesize());
if (stream->workspace == NULL)
goto failed;
@@ -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);
}
@@ -56,7 +56,7 @@ static void zlib_free(void *strm)
z_stream *stream = strm;
if (stream)
- kfree(stream->workspace);
+ vfree(stream->workspace);
kfree(stream);
}