Squashfs: move zlib decompression wrapper code into a separate file

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

4 files changed, 118 insertions, 71 deletions

diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile
index 70e3244fa30f..a397e6f12ab5 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
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 2a7960310349..b8addfdc6094 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -29,7 +29,6 @@
 #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>
@@ -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_zlib_uncompress(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/squashfs.h b/fs/squashfs/squashfs.h
index 0e9feb6adf7e..ba87db693651 100644
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -70,6 +70,10 @@ extern struct inode *squashfs_iget(struct super_block *, long long,
                                 unsigned int);
 extern int squashfs_read_inode(struct inode *, long long);
 
+/* zlib_wrapper.c */
+extern int squashfs_zlib_uncompress(struct squashfs_sb_info *, void **,
+                                struct buffer_head **, int, int, int, int, int);
+
 /*
  * Inodes and files operations
  */
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
new file mode 100644
index 000000000000..3be99642d6af
--- /dev/null
+++ b/fs/squashfs/zlib_wrapper.c
@@ -0,0 +1,109 @@
+/*
+ * 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"
+
+int squashfs_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;
+
+        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;
+        }
+
+        mutex_unlock(&msblk->read_data_mutex);
+        return msblk->stream.total_out;
+
+release_mutex:
+        mutex_unlock(&msblk->read_data_mutex);
+
+        for (; k < b; k++)
+                put_bh(bh[k]);
+
+        return -EIO;
+}