cloop 2.01-1 update (support for older formats in 2.6.x)

I needed support for 1.0 and .68 formats in cloop. With the driver and devfs changes in 2.6, it was easier to migrate the changes to 2.01-1 than to port. So I made a patch. cloop should read all formats correctly.
2.6.4 should also work now (minior changes to module init/exit routines).
Aplolgies if this was done already...

Code:

---

--- cloop-2.01.orig/compressed_loop.c        2004-02-05 20:14:19.000000000 -0500
+++ cloop-2.01/compressed_loop.c        2004-03-04 01:19:07.000000000 -0500
@@ -16,6 +16,9 @@
  * Redistribution of this file is permitted under the GNU Public License.
  *
  * CHANGES: (see CHANGELOG file)
+ *  ([email protected]) 2003.03.03
+ *  Support for reading 1.0 and .68 formats
+ *  Changed module init/exit routines so 2.6.4 works
  */
 
 #define CLOOP_NAME "cloop"
@@ -25,6 +28,8 @@
 /* Define this if you are using Greenshoe Linux */
 /* #define REDHAT_KERNEL */
 
+#include <linux/types.h>
+#include <linux/init.h>
 #include <linux/version.h>
 #include <linux/module.h>
 #include <linux/sched.h>
@@ -89,6 +94,10 @@
 #define DEBUGP(format, x...)
 #endif
 
+#define ntohl(x) __be32_to_cpu(x)
+static int read_ver=210;
+static size_t offsets_size = sizeof(loff_t);
+
 /* One file can be opened at module insertion time */
 /* insmod cloop file=/path/to/file */
 static char *file=NULL;
@@ -103,6 +112,7 @@
 
  /* An array of offsets of compressed blocks within the file */
  loff_t *offsets;
+ u_int32_t *offsets32;
 
  /* We buffer one uncompressed `block' */
  int buffered_blocknum;
@@ -208,7 +218,7 @@
 }
 
 static size_t clo_read_from_file(struct cloop_device *clo, struct file *f, char *buf,
-  loff_t pos, size_t buf_len)
+ loff_t pos, size_t buf_len)
 {
  size_t buf_done=0;
  while (buf_done < buf_len)
@@ -258,14 +268,36 @@
    return 0;
  }
 
+
  if (blocknum == clo->buffered_blocknum) return 1;
 
  /* Is there a ntohl for 64-bit values? */
+if (read_ver>=200)
  buf_length = be64_to_cpu(clo->offsets[blocknum+1]) - be64_to_cpu(clo->offsets[blocknum]);
+else
+if (read_ver>=100 && read_ver<200)
+ buf_length = clo->offsets[blocknum+1] - clo->offsets[blocknum];
+else
+if (read_ver<100)
+ buf_length = ntohl(clo->offsets32[blocknum+1]) - ntohl(clo->offsets32[blocknum]);
+
 
 /* Load one compressed block from the file. */
+if (read_ver>=200)
  clo_read_from_file(clo, clo->backing_file, (char *)clo->compressed_buffer,
                    be64_to_cpu(clo->offsets[blocknum]), buf_length);
+else
+if (read_ver>=100 && read_ver<200)
+ clo_read_from_file(clo, clo->backing_file, (char *)clo->compressed_buffer,
+                    clo->offsets[blocknum], buf_length);
+else
+if (read_ver<100)
+{
+ loff_t offval = 0;
+ offval=ntohl(clo->offsets32[blocknum]);
+ clo_read_from_file(clo, clo->backing_file, (char *)clo->compressed_buffer,
+                    offval, buf_length);
+}
 
  /* Do decompression into real buffer. */
  buflen = ntohl(clo->head.block_size);
@@ -273,13 +305,29 @@
  /* Do the uncompression */
  ret = uncompress(clo, clo->buffer, &buflen, clo->compressed_buffer,
                  buf_length);
+
+
  /* DEBUGP("cloop: buflen after uncompress: %ld\n",buflen); */
  if (ret != 0)
  {
+  if (read_ver>=200)
    printk(KERN_ERR "%s: error %i uncompressing block %u %u/%lu/%u/%u "
          "%Lu-%Lu\n", cloop_name, ret, blocknum,
          ntohl(clo->head.block_size), buflen, buf_length, buf_done,
          be64_to_cpu(clo->offsets[blocknum]), be64_to_cpu(clo->offsets[blocknum+1]));
+  else
+  if (read_ver>=100 && read_ver<200)
+  printk(KERN_ERR "%s: error %i uncompressing block %u %u/%lu/%u/%u "
+          "%Lu-%Lu\n", cloop_name, ret, blocknum,
+          ntohl(clo->head.block_size), buflen, buf_length, buf_done,
+          clo->offsets[blocknum], clo->offsets[blocknum+1]);
+  else
+  if (read_ver<100)
+  printk(KERN_ERR "%s: error %i uncompressing block %u %u/%lu/%u/%u "
+          "%u-%u\n", cloop_name, ret, blocknum,
+          ntohl(clo->head.block_size), buflen, buf_length, buf_done,
+          ntohl(clo->offsets32[blocknum]), ntohl(clo->offsets32[blocknum+1]));
+
    clo->buffered_blocknum = -1;
    return 0;
  }
@@ -300,6 +348,7 @@
 #endif
  unsigned int len;
  loff_t offset;
+ u_int32_t offset32;
  char *dest;
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
@@ -345,11 +394,17 @@
 
  down(&cloop->clo_lock);
  len        = bh->b_size;
+ if (read_ver >= 100)
  offset    = (loff_t)bh->b_rsector << 9;
+ else
+ offset32  = (u_int32_t)bh->b_rsector << 9;
  dest      = bh->b_data;
 #else
  down(&cloop->clo_lock);
+ if (read_ver >= 100)
  offset    = (loff_t)bio->bi_sector << 9;
+ else
+ offset32  = (u_int32_t)bio->bi_sector << 9;
  for(vecnr=0; vecnr < bio->bi_vcnt; vecnr++)
  {
    struct bio_vec *bvec=&bio->bi_io_vec[vecnr];
@@ -368,11 +423,21 @@
    /* becomes the blocknumber to load, and offset_in_buffer the  */
    /* position in the buffer */
    u_int32_t offset_in_buffer;
-  offset_in_buffer = do_div(block_offset, ntohl(cloop->head.block_size));
-
-  status=load_buffer(cloop,block_offset);
+
+  if (read_ver >= 100)
+  {
+    offset_in_buffer = do_div(block_offset, ntohl(cloop->head.block_size));
+    status=load_buffer(cloop,block_offset);
+  }
+  else
+  {
+    status=load_buffer(cloop,offset32/ntohl(cloop->head.block_size));
+    if (!status) break;
+    offset_in_buffer = offset32 % ntohl(cloop->head.block_size);
+  }
+
    if(!status) break; /* invalid data, leave inner loop, goto next request */
- 
+
    /* Now, at least part of what we want will be in the buffer. */
    length_in_buffer = ntohl(cloop->head.block_size) - offset_in_buffer;
 
@@ -387,7 +452,10 @@
 
    dest  += length_in_buffer;
    len    -= length_in_buffer;
+  if (read_ver >= 100)
    offset += length_in_buffer;
+  else
+  offset32 += length_in_buffer;
  } /* while inner loop */
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0)
@@ -498,24 +566,25 @@
 
      if (clo->head.preamble[0x0B]!='V'||clo->head.preamble[0x0C]<'1')
      {
-      printk(KERN_ERR "%s: Cannot read old 32-bit (version 0.68) images, "
-                      "please use an older version of %s for this file.\n",
-                      cloop_name, cloop_name);
-      error=-EBADF; goto error_release;
+      printk(KERN_WARNING "%s: Reading old 32-bit (version 0.68) image.\n",
+                          cloop_name);
+      read_ver = 68;
+      offsets_size = sizeof(u_int32_t);
      }
 
      if (clo->head.preamble[0x0C]<'2')
      {
-      printk(KERN_ERR "%s: Cannot read old architecture-dependent "
-                      "(format <= 1.0) images, please use an older "
-                      "version of %s for this file.\n",
-                      cloop_name, cloop_name);
-      error=-EBADF; goto error_release;
+      printk(KERN_WARNING "%s: Reading old architecture-dependent "
+                          "(format <= 1.0) image. \n",
+                          cloop_name);
+
+      read_ver = 100;
+      offsets_size = sizeof(loff_t);
      }
 
      total_offsets=ntohl(clo->head.num_blocks)+1;
 
-    if (!isblkdev && (sizeof(struct cloop_head)+sizeof(loff_t)*
+    if (!isblkdev && (sizeof(struct cloop_head)+offsets_size*
                        total_offsets > inode->i_size))
      {
        printk(KERN_ERR "%s: file too small for %u blocks\n",
@@ -523,26 +592,56 @@
        error=-EBADF; goto error_release;
      }
 
-    clo->offsets = vmalloc(sizeof(loff_t) * total_offsets);
-    if (!clo->offsets)
-      {
-      printk(KERN_ERR "%s: out of kernel mem for offsets\n", cloop_name);
-      error=-ENOMEM; goto error_release;
-      }
+    if (read_ver >= 100)
+    {
+            clo->offsets = vmalloc(offsets_size * total_offsets);
+                if (!clo->offsets)
+                  {
+                      printk(KERN_ERR "%s: out of kernel mem for offsets\n", cloop_name);
+                      error=-ENOMEM; goto error_release;
+                  }
+    }
+    else
+    {
+            clo->offsets32 = vmalloc(offsets_size * total_offsets);
+              if (!clo->offsets32)
+                {
+                      printk(KERN_ERR "%s: out of kernel mem for offsets\n", cloop_name);
+                      error=-ENOMEM; goto error_release;
+                }
+    }
+
+
    }
 
    num_readable = MIN(total_offsets - offsets_read,
                      (clo->underlying_blksize - offset)
-                      / sizeof(loff_t));
-  memcpy(&clo->offsets[offsets_read], bbuf+offset, num_readable * sizeof(loff_t));
+                      / offsets_size);
+
+
+  if (read_ver >= 100)
+  memcpy(&clo->offsets[offsets_read], bbuf+offset, num_readable * offsets_size);
+  else
+  memcpy(&clo->offsets32[offsets_read], bbuf+offset, num_readable * offsets_size);
+
    offsets_read += num_readable;
  }
 
+
  { /* Search for largest block rather than estimate. KK. */
    int i;
    for(i=0;i<total_offsets-1;i++)
    {
-    loff_t d=be64_to_cpu(clo->offsets[i+1]) - be64_to_cpu(clo->offsets[i]);
+    loff_t d;
+    if (read_ver>=200)
+            d=be64_to_cpu(clo->offsets[i+1]) - be64_to_cpu(clo->offsets[i]);
+    else
+    if (read_ver>=100 && read_ver<200)
+        d=clo->offsets[i+1] - clo->offsets[i];
+    else
+    if (read_ver<100)
+        d=ntohl(clo->offsets32[i+1]) - ntohl(clo->offsets32[i]);
+
      largest_block=MAX(largest_block,d);
    }
    printk("%s: %s: %u blocks, %u bytes/block, largest block is %lu bytes.\n",
@@ -576,7 +675,7 @@
  }
  zlib_inflateInit(&clo->zstream);
 
- if(!isblkdev &&
+ if(read_ver>=200 && !isblkdev &&
    be64_to_cpu(clo->offsets[ntohl(clo->head.num_blocks)]) != inode->i_size)
  {
    printk(KERN_ERR "%s: final offset wrong (%Lu not %Lu)\n",
@@ -586,6 +685,29 @@
    vfree(clo->zstream.workspace); clo->zstream.workspace=NULL;
    goto error_release_free_all;
  }
+ else
+ if((read_ver>=100 && read_ver<200) && !isblkdev &&
+    clo->offsets[ntohl(clo->head.num_blocks)] != inode->i_size)
+  {
+  printk(KERN_ERR "%s: final offset wrong (%Lu not %Lu)\n",
+          cloop_name,
+          clo->offsets[ntohl(clo->head.num_blocks)],
+          inode->i_size);
+  vfree(clo->zstream.workspace); clo->zstream.workspace=NULL;
+  goto error_release_free_all;
+  }
+ else
+ if(read_ver<100 && !isblkdev &&
+    ntohl(clo->offsets32[ntohl(clo->head.num_blocks)]) != inode->i_size)
+  {
+  printk(KERN_ERR "%s: final offset wrong (%u not %Lu)\n",
+          cloop_name,
+          ntohl(clo->offsets32[ntohl(clo->head.num_blocks)]),
+          inode->i_size);
+  vfree(clo->zstream.workspace); clo->zstream.workspace=NULL;
+  goto error_release_free_all;
+  }
+       
 
  clo->buffered_blocknum = -1;
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
@@ -605,8 +727,12 @@
  vfree(clo->buffer);
  clo->buffer=NULL;
 error_release_free:
+ if (read_ver >= 100)
  vfree(clo->offsets);
+ else
+ vfree(clo->offsets32);
  clo->offsets=NULL;
+ clo->offsets32=NULL;
 error_release:
  if(bbuf) vfree(bbuf);
  clo->backing_file=NULL;
@@ -756,7 +882,7 @@
        ioctl:          clo_ioctl
 };
 
-static int cloop_init(void)
+static int __init cloop_init(void)
 {
  int i, error=0;
  printk("%s: Initializing %s v"CLOOP_VERSION"\n", cloop_name, cloop_name);
@@ -845,7 +971,7 @@
  return error;
 }
 
-static void cloop_exit(void)
+static void __exit cloop_exit(void)
 {
  int i;
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
@@ -863,6 +989,7 @@
    put_disk(cloop_dev[i].disk);
 #endif
    if(cloop_dev[i].offsets) vfree(cloop_dev[i].offsets);
+  if(cloop_dev[i].offsets32) vfree(cloop_dev[i].offsets32);
    if(cloop_dev[i].buffer)  vfree(cloop_dev[i].buffer);
    if(cloop_dev[i].compressed_buffer) vfree(cloop_dev[i].compressed_buffer);
    zlib_inflateEnd(&cloop_dev[i].zstream);

---

BC, since you seem to know what is going on with cloop.o, could you take a look at my post http://www.knoppix.net/forum/viewtop...?p=39328#39328
and see if you can tell me what is wrong? Thanks.