Fix for rare race condition that (mainly) occurs on SMP systems

2 files changed, 23 insertions, 17 deletions

diff --git a/kernel-2.4/fs/squashfs/inode.c b/kernel-2.4/fs/squashfs/inode.c
index 22f3743..3466356 100755
--- a/kernel-2.4/fs/squashfs/inode.c
+++ b/kernel-2.4/fs/squashfs/inode.c
@@ -26,13 +26,13 @@
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
+#include <linux/zlib.h>
 #include <linux/fs.h>
 #include <linux/smp_lock.h>
 #include <linux/locks.h>
 #include <linux/init.h>
 #include <linux/dcache.h>
 #include <linux/wait.h>
-#include <linux/zlib.h>
 #include <linux/blkdev.h>
 #include <linux/vmalloc.h>
 #include <asm/uaccess.h>
@@ -53,7 +53,7 @@ static long long read_blocklist(struct inode *inode, int index,
 				int readahead_blks, char *block_list,
 				unsigned short **block_p, unsigned int *bsize);
 
-static z_stream stream;
+/*static z_stream stream;*/
 
 static DECLARE_FSTYPE_DEV(squashfs_fs_type, "squashfs", squashfs_read_super);
 
@@ -229,20 +229,20 @@ SQSH_EXTERN unsigned int squashfs_read_data(struct super_block *s, char *buffer,
 	if (compressed) {
 		int zlib_err;
 
-		stream.next_in = c_buffer;
-		stream.avail_in = c_byte;
-		stream.next_out = buffer;
-		stream.avail_out = msblk->read_size;
+		msblk->stream.next_in = c_buffer;
+		msblk->stream.avail_in = c_byte;
+		msblk->stream.next_out = buffer;
+		msblk->stream.avail_out = msblk->read_size;
 
-		if (((zlib_err = zlib_inflateInit(&stream)) != Z_OK) ||
-				((zlib_err = zlib_inflate(&stream, Z_FINISH))
+		if (((zlib_err = zlib_inflateInit(&msblk->stream)) != Z_OK) ||
+				((zlib_err = zlib_inflate(&msblk->stream, Z_FINISH))
 				 != Z_STREAM_END) || ((zlib_err =
-				zlib_inflateEnd(&stream)) != Z_OK)) {
+				zlib_inflateEnd(&msblk->stream)) != Z_OK)) {
 			ERROR("zlib_fs returned unexpected result 0x%x\n",
 				zlib_err);
 			bytes = 0;
 		} else
-			bytes = stream.total_out;
+			bytes = msblk->stream.total_out;
 		
 		up(&msblk->read_data_mutex);
 	}
@@ -936,7 +936,12 @@ static struct super_block *squashfs_read_super(struct super_block *s,
 	struct squashfs_super_block *sblk = &msblk->sblk;
 	int i;
 	struct inode *root;
-	
+
+	if (!(msblk->stream.workspace = vmalloc(zlib_inflate_workspacesize()))) {
+		ERROR("Failed to allocate zlib workspace\n");
+		goto failed_mount;
+	}
+
 	msblk->devblksize = get_hardsect_size(dev);
 	if(msblk->devblksize < BLOCK_SIZE)
 		msblk->devblksize = BLOCK_SIZE;
@@ -1111,6 +1116,7 @@ failed_mount:
 	kfree(msblk->read_data);
 	kfree(msblk->block_cache);
 	kfree(msblk->fragment_index_2);
+	vfree(msblk->stream.workspace);
 	return NULL;
 }
 
@@ -1988,6 +1994,8 @@ static void squashfs_put_super(struct super_block *s)
 		kfree(sbi->uid);
 		kfree(sbi->fragment_index);
 		kfree(sbi->fragment_index_2);
+		kfree(sbi->meta_index);
+		vfree(sbi->stream.workspace);
 		sbi->block_cache = NULL;
 		sbi->uid = NULL;
 		sbi->read_data = NULL;
@@ -1995,26 +2003,23 @@ static void squashfs_put_super(struct super_block *s)
 		sbi->fragment = NULL;
 		sbi->fragment_index = NULL;
 		sbi->fragment_index_2 = NULL;
+		sbi->meta_index = NULL;
+		sbi->stream.workspace = NULL;
 }
 
 
 static int __init init_squashfs_fs(void)
 {
 
-	printk(KERN_INFO "squashfs: version 3.0 (2006/03/15) "
+	printk(KERN_INFO "squashfs: version 3.1-test (2006/07/31) "
 		"Phillip Lougher\n");
 
-	if (!(stream.workspace = vmalloc(zlib_inflate_workspacesize()))) {
-		ERROR("Failed to allocate zlib workspace\n");
-		return -ENOMEM;
-	}
 	return register_filesystem(&squashfs_fs_type);
 }
 
 
 static void __exit exit_squashfs_fs(void)
 {
-	vfree(stream.workspace);
 	unregister_filesystem(&squashfs_fs_type);
 }
 
diff --git a/kernel-2.4/fs/squashfs/squashfs2_0.c b/kernel-2.4/fs/squashfs/squashfs2_0.c
index d4efd8a..4eabfa5 100755
--- a/kernel-2.4/fs/squashfs/squashfs2_0.c
+++ b/kernel-2.4/fs/squashfs/squashfs2_0.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
+#include <linux/zlib.h>
 #include <linux/fs.h>
 #include <linux/smp_lock.h>
 #include <linux/locks.h>