15 files changed, 203 insertions, 30 deletions

diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
index e5f63da64d04..aa68a8a31518 100644
--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -29,7 +29,6 @@ config SQUASHFS
 config SQUASHFS_XATTR
         bool "Squashfs XATTR support"
         depends on SQUASHFS
-        default n
         help
           Saying Y here includes support for extended attributes (xattrs).
           Xattrs are name:value pairs associated with inodes by
@@ -40,7 +39,6 @@ config SQUASHFS_XATTR
 config SQUASHFS_LZO
         bool "Include support for LZO compressed file systems"
         depends on SQUASHFS
-        default n
         select LZO_DECOMPRESS
         help
           Saying Y here includes support for reading Squashfs file systems
@@ -53,10 +51,24 @@ config SQUASHFS_LZO
 
           If unsure, say N.
 
+config SQUASHFS_XZ
+        bool "Include support for XZ compressed file systems"
+        depends on SQUASHFS
+        select XZ_DEC
+        help
+          Saying Y here includes support for reading Squashfs file systems
+          compressed with XZ compresssion.  XZ gives better compression than
+          the default zlib compression, at the expense of greater CPU and
+          memory overhead.
+
+          XZ is not the standard compression used in Squashfs and so most
+          file systems will be readable without selecting this option.
+
+          If unsure, say N.
+
 config SQUASHFS_EMBEDDED
         bool "Additional option for memory-constrained systems"
         depends on SQUASHFS
-        default n
         help
           Saying Y here allows you to specify cache size.
 
diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile
index 7672bac8d328..cecf2bea07af 100644
--- a/fs/squashfs/Makefile
+++ b/fs/squashfs/Makefile
@@ -7,3 +7,4 @@ 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 zlib_wrapper.o decompressor.o
 squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
 squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
+squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 653c030eb840..2fb2882f0fa7 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -34,7 +34,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 #include "decompressor.h"
 
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c
index 57314bee9059..26b15ae34d6f 100644
--- a/fs/squashfs/cache.c
+++ b/fs/squashfs/cache.c
@@ -55,7 +55,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 
 /*
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index 24af9ce9722f..a5940e54c4dd 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -27,7 +27,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "decompressor.h"
 #include "squashfs.h"
 
@@ -41,23 +40,26 @@ static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
 };
 
 #ifndef CONFIG_SQUASHFS_LZO
-static const struct squashfs_decompressor squashfs_lzo_unsupported_comp_ops = {
+static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
         NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
 };
 #endif
 
+#ifndef CONFIG_SQUASHFS_XZ
+static const struct squashfs_decompressor squashfs_xz_comp_ops = {
+        NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
+};
+#endif
+
 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,
-#ifdef CONFIG_SQUASHFS_LZO
         &squashfs_lzo_comp_ops,
-#else
-        &squashfs_lzo_unsupported_comp_ops,
-#endif
+        &squashfs_xz_comp_ops,
+        &squashfs_lzma_unsupported_comp_ops,
         &squashfs_unknown_comp_ops
 };
 
diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h
index 7425f80783f6..3b305a70f7aa 100644
--- a/fs/squashfs/decompressor.h
+++ b/fs/squashfs/decompressor.h
@@ -52,4 +52,13 @@ static inline int squashfs_decompress(struct squashfs_sb_info *msblk,
         return msblk->decompressor->decompress(msblk, buffer, bh, b, offset,
                 length, srclength, pages);
 }
+
+#ifdef CONFIG_SQUASHFS_XZ
+extern const struct squashfs_decompressor squashfs_xz_comp_ops;
+#endif
+
+#ifdef CONFIG_SQUASHFS_LZO
+extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
+#endif
+
 #endif
diff --git a/fs/squashfs/fragment.c b/fs/squashfs/fragment.c
index 7c90bbd6879d..7eef571443c6 100644
--- a/fs/squashfs/fragment.c
+++ b/fs/squashfs/fragment.c
@@ -39,7 +39,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 
 /*
diff --git a/fs/squashfs/id.c b/fs/squashfs/id.c
index b7f64bcd2b70..d8f32452638e 100644
--- a/fs/squashfs/id.c
+++ b/fs/squashfs/id.c
@@ -37,7 +37,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 
 /*
diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
index 5d87789bf1c1..7da759e34c52 100644
--- a/fs/squashfs/lzo_wrapper.c
+++ b/fs/squashfs/lzo_wrapper.c
@@ -29,7 +29,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 #include "decompressor.h"
 
diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h
index 5d45569d5f72..ba729d808876 100644
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -27,11 +27,6 @@
 
 #define WARNING(s, args...)     pr_warning("SQUASHFS: "s, ## args)
 
-static inline struct squashfs_inode_info *squashfs_i(struct inode *inode)
-{
-        return list_entry(inode, struct squashfs_inode_info, vfs_inode);
-}
-
 /* block.c */
 extern int squashfs_read_data(struct super_block *, void **, u64, int, u64 *,
                                 int, int);
@@ -104,6 +99,3 @@ extern const struct xattr_handler *squashfs_xattr_handlers[];
 
 /* zlib_wrapper.c */
 extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
-
-/* lzo_wrapper.c */
-extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h
index c5137fc9ab11..39533feffd6d 100644
--- a/fs/squashfs/squashfs_fs.h
+++ b/fs/squashfs/squashfs_fs.h
@@ -238,6 +238,7 @@ struct meta_index {
 #define ZLIB_COMPRESSION        1
 #define LZMA_COMPRESSION        2
 #define LZO_COMPRESSION         3
+#define XZ_COMPRESSION          4
 
 struct squashfs_super_block {
         __le32                  s_magic;
diff --git a/fs/squashfs/squashfs_fs_i.h b/fs/squashfs/squashfs_fs_i.h
index d3e3a37f28a1..359baefc01fc 100644
--- a/fs/squashfs/squashfs_fs_i.h
+++ b/fs/squashfs/squashfs_fs_i.h
@@ -45,4 +45,10 @@ struct squashfs_inode_info {
         };
         struct inode    vfs_inode;
 };
+
+
+static inline struct squashfs_inode_info *squashfs_i(struct inode *inode)
+{
+        return list_entry(inode, struct squashfs_inode_info, vfs_inode);
+}
 #endif
diff --git a/fs/squashfs/xattr_id.c b/fs/squashfs/xattr_id.c
index d33be5dd6c32..05385dbe1465 100644
--- a/fs/squashfs/xattr_id.c
+++ b/fs/squashfs/xattr_id.c
@@ -32,7 +32,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 #include "xattr.h"
 
diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c
new file mode 100644
index 000000000000..856756ca5ee4
--- /dev/null
+++ b/fs/squashfs/xz_wrapper.c
@@ -0,0 +1,153 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ * 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.
+ *
+ * xz_wrapper.c
+ */
+
+
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/xz.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+#include "decompressor.h"
+
+struct squashfs_xz {
+        struct xz_dec *state;
+        struct xz_buf buf;
+};
+
+static void *squashfs_xz_init(struct squashfs_sb_info *msblk)
+{
+        int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
+
+        struct squashfs_xz *stream = kmalloc(sizeof(*stream), GFP_KERNEL);
+        if (stream == NULL)
+                goto failed;
+
+        stream->state = xz_dec_init(XZ_PREALLOC, block_size);
+        if (stream->state == NULL)
+                goto failed;
+
+        return stream;
+
+failed:
+        ERROR("Failed to allocate xz workspace\n");
+        kfree(stream);
+        return NULL;
+}
+
+
+static void squashfs_xz_free(void *strm)
+{
+        struct squashfs_xz *stream = strm;
+
+        if (stream) {
+                xz_dec_end(stream->state);
+                kfree(stream);
+        }
+}
+
+
+static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void **buffer,
+        struct buffer_head **bh, int b, int offset, int length, int srclength,
+        int pages)
+{
+        enum xz_ret xz_err;
+        int avail, total = 0, k = 0, page = 0;
+        struct squashfs_xz *stream = msblk->stream;
+
+        mutex_lock(&msblk->read_data_mutex);
+
+        xz_dec_reset(stream->state);
+        stream->buf.in_pos = 0;
+        stream->buf.in_size = 0;
+        stream->buf.out_pos = 0;
+        stream->buf.out_size = PAGE_CACHE_SIZE;
+        stream->buf.out = buffer[page++];
+
+        do {
+                if (stream->buf.in_pos == stream->buf.in_size && k < b) {
+                        avail = min(length, msblk->devblksize - offset);
+                        length -= 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->buf.in = bh[k]->b_data + offset;
+                        stream->buf.in_size = avail;
+                        stream->buf.in_pos = 0;
+                        offset = 0;
+                }
+
+                if (stream->buf.out_pos == stream->buf.out_size
+                                                        && page < pages) {
+                        stream->buf.out = buffer[page++];
+                        stream->buf.out_pos = 0;
+                        total += PAGE_CACHE_SIZE;
+                }
+
+                xz_err = xz_dec_run(stream->state, &stream->buf);
+
+                if (stream->buf.in_pos == stream->buf.in_size && k < b)
+                        put_bh(bh[k++]);
+        } while (xz_err == XZ_OK);
+
+        if (xz_err != XZ_STREAM_END) {
+                ERROR("xz_dec_run error, data probably corrupt\n");
+                goto release_mutex;
+        }
+
+        if (k < b) {
+                ERROR("xz_uncompress error, input remaining\n");
+                goto release_mutex;
+        }
+
+        total += stream->buf.out_pos;
+        mutex_unlock(&msblk->read_data_mutex);
+        return total;
+
+release_mutex:
+        mutex_unlock(&msblk->read_data_mutex);
+
+        for (; k < b; k++)
+                put_bh(bh[k]);
+
+        return -EIO;
+}
+
+const struct squashfs_decompressor squashfs_xz_comp_ops = {
+        .init = squashfs_xz_init,
+        .free = squashfs_xz_free,
+        .decompress = squashfs_xz_uncompress,
+        .id = XZ_COMPRESSION,
+        .name = "xz",
+        .supported = 1
+};
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 7a603874e483..818a5e063faf 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -29,7 +29,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 #include "decompressor.h"
 
@@ -66,8 +65,8 @@ 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;
+        int zlib_err, zlib_init = 0;
+        int k = 0, page = 0;
         z_stream *stream = msblk->stream;
 
         mutex_lock(&msblk->read_data_mutex);
@@ -75,11 +74,10 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
         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;
+                        int avail = min(length, msblk->devblksize - offset);
+                        length -= avail;
                         wait_on_buffer(bh[k]);
                         if (!buffer_uptodate(bh[k]))
                                 goto release_mutex;
@@ -128,6 +126,11 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
                 goto release_mutex;
         }
 
+        if (k < b) {
+                ERROR("zlib_uncompress error, data remaining\n");
+                goto release_mutex;
+        }
+
         length = stream->total_out;
         mutex_unlock(&msblk->read_data_mutex);
         return length;