compressed_loop.c patch

cloop-2.624-kernel_2.6.25.patch (text/plain), 11.38 KB, created by Yogesh on 2008-07-12 01:59:47 UTC

--- compressed_loop.c	2008-07-11 18:40:51.356951242 -0700
+++ /tmp/compressed_loop.c	2008-07-11 18:39:03.676141237 -0700
@@ -20,7 +20,7 @@
  */
 
 #define CLOOP_NAME "cloop"
-#define CLOOP_VERSION "2.624"
+#define CLOOP_VERSION "2.625"
 #define CLOOP_MAX 8
 
 #ifndef KBUILD_MODNAME
@@ -124,6 +124,7 @@
  int current_bufnum;
  void *buffer[BUFFERED_BLOCKS];
  void *compressed_buffer;
+ size_t preload_size;
  void *preload_cache;
 
  z_stream zstream;
@@ -131,6 +132,7 @@
  struct file   *backing_file;  /* associated file */
  struct inode  *backing_inode; /* for bmap */
 
+ unsigned long largest_block;
  unsigned int underlying_blksize;
  int clo_number;
  int refcnt;
@@ -156,6 +158,18 @@
 #error  "Invalid Kernel configuration. CONFIG_ZLIB_INFLATE support is needed for cloop."
 #endif
 
+/* Use __get_free_pages instead of vmalloc, allows up to 32 pages,
+ * 2MB in one piece */
+static void *cloop_malloc(size_t size)
+{
+ return (void *)__get_free_pages(GFP_KERNEL, get_order(size));
+}
+
+static void cloop_free(void *mem, size_t size)
+{
+ free_pages((unsigned long)mem, get_order(size));
+}
+
 static int uncompress(struct cloop_device *clo,
                       unsigned char *dest, unsigned long *destLen,
                       unsigned char *source, unsigned long sourceLen)
@@ -178,32 +192,6 @@
  return Z_OK;
 }
 
-/* This is more complicated than it looks. */
-struct cloop_read_data
-{
- struct cloop_device *clo;
- char *data; /* We need to keep track of where we are in the buffer */
- int bsize;
-};
-
-/* We need this for do_generic_file_read() because the default function */
-/* wants to read into user-space for an unknown reason. :-/ See loop.c. */
-static int cloop_read_actor(read_descriptor_t * desc, struct page *page,
-                          unsigned long offset, unsigned long size)
-{
- unsigned long count = desc->count;
- struct cloop_read_data *p = (struct cloop_read_data*)desc->arg.data;
- char *kaddr_page;
- if (size > count) size = count;
- kaddr_page = kmap(page);
- memcpy(p->data, kaddr_page + offset, size);
- kunmap(page);
- desc->count = count - size;
- desc->written += size;
- p->data += size;
- return size;
-}
-
 static size_t cloop_read_from_file(struct cloop_device *clo, struct file *f, char *buf,
   loff_t pos, size_t buf_len)
 {
@@ -211,35 +199,21 @@
  while (buf_done < buf_len)
   {
    size_t size = buf_len - buf_done;
-   struct cloop_read_data cd={ /* do_generic_file_read() needs this. */
-           clo,              /* struct cloop_device *clo */
-           (char *)(buf + buf_done), /* char *data */
-           size};            /* Actual data size */
-   read_descriptor_t desc;
-   desc.written = 0;
-   desc.count   = size;
-   desc.arg.data = (char*)&cd;
-   desc.error   = 0;
-#ifdef REDHAT_KERNEL /* Greenshoe Linux */
-   do_generic_file_read(f, &pos, &desc, cloop_read_actor, 0);
-#else /* Normal Kernel */
-   do_generic_file_read(f, &pos, &desc, cloop_read_actor);
-#endif
-   if(desc.error||desc.written<=0)
+   size_t size_read = do_sync_read(f, buf +  buf_done, size, &pos);
+   if(size_read <= 0)
     {
-     int left = size - desc.written;
+     size_t left = size - size_read;
      if(left<0) left = 0; /* better safe than sorry */
      printk(KERN_ERR "%s: Read error at pos %Lu in file %s, "
                      "%d bytes lost.\n", cloop_name, pos, file, left);
      memset(buf + buf_len - left, 0, left);
      break;
     }
-   buf_done += desc.written;
+   buf_done += size_read;
   }
  return buf_done;
 }
 
-
 /* This looks more complicated than it is */
 /* Returns number of block buffer to use for this request */
 static int cloop_load_buffer(struct cloop_device *clo, int blocknum)
@@ -300,7 +274,6 @@
 {
  int buffered_blocknum = -1;
  int preloaded = 0;
- struct bio *bio;
  loff_t offset     = (loff_t) req->sector<<9;
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)  /* New kernel */
  struct bio_vec *bvec;
@@ -351,6 +324,7 @@
    kunmap(bvec->bv_page);
   } /* end rq_for_each_segment*/
 #else /* Old Kernel */
+ struct bio *bio;
  rq_for_each_bio(bio, req)
   {
    struct bio_vec *bvec;
@@ -425,22 +399,27 @@
    list_for_each_safe(p, n, &clo->clo_list)
     {
      int uptodate;
+     unsigned long flags;
      struct request *req;
+     spin_lock_irqsave(&clo->queue_lock, flags);
      req = list_entry(p, struct request, queuelist);
-     spin_lock_irq(&clo->queue_lock);
      list_del_init(&req->queuelist);
-     spin_unlock_irq(&clo->queue_lock);
-/*     DEBUGP(KERN_ERR "cloop_handle_request(%p, %p), sector=%d, nr_sectors=%d, current_nr_sectors=%d ", clo, req, (int)req->sector, (int)req->nr_sectors, (int)req->current_nr_sectors); */
+     spin_unlock_irqrestore(&clo->queue_lock, flags);
      uptodate = cloop_handle_request(clo, req);
-/*     DEBUGP(KERN_ERR "cloop_handle_request done, uptodate=%d\n", uptodate); */
-     spin_lock_irq(&clo->queue_lock);
+     spin_lock_irqsave(&clo->queue_lock, flags);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)  /* New kernel */
+     __blk_end_request(req, uptodate ? 0 : -EIO, req->nr_sectors << 9);
+#else
      if(!end_that_request_first(req, uptodate, req->nr_sectors))
        end_that_request_last(req, uptodate);
-     spin_unlock_irq(&clo->queue_lock);
+#endif
+     spin_unlock_irqrestore(&clo->queue_lock, flags);
     }
+#if 0
    spin_lock_irq(&clo->queue_lock);
    blk_start_queue(clo->clo_queue);
    spin_unlock_irq(&clo->queue_lock);
+#endif
   }
  DEBUGP(KERN_ERR "cloop_thread exited.\n");
  return 0;
@@ -475,7 +454,9 @@
      goto error_continue;
     }
    blkdev_dequeue_request(req); /* Dequeue request first. */
+#if 0
    blk_stop_queue(q);           /* Stop queue processing */
+#endif
    list_add(&req->queuelist, &clo->clo_list); /* Add to working list for thread */
    count++;
    wake_up(&clo->clo_event);    /* Wake up cloop_thread */
@@ -483,7 +464,11 @@
   error_continue:
    DEBUGP(KERN_ERR "cloop_do_request: Discarding request %p.\n", req);
    req->errors++;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)  /* New kernel */
+   __blk_end_request(req, -EIO, req->nr_sectors << 9);
+#else
    end_request(req, 0); /* Discard */
+#endif
   }
 }
 
@@ -494,7 +479,6 @@
  struct inode *inode;
  char *bbuf=NULL;
  unsigned int i, offsets_read, total_offsets;
- unsigned long largest_block=0;
  int isblkdev;
  int error = 0;
  inode = file->f_dentry->d_inode;
@@ -531,7 +515,7 @@
  else
    clo->underlying_blksize = PAGE_SIZE;
  DEBUGP("Underlying blocksize is %u\n", clo->underlying_blksize);
- bbuf = vmalloc(clo->underlying_blksize);
+ bbuf = cloop_malloc(clo->underlying_blksize);
  if(!bbuf)
   {
    printk(KERN_ERR "%s: out of kernel mem for block buffer (%lu bytes)\n",
@@ -580,7 +564,7 @@
               cloop_name, ntohl(clo->head.num_blocks));
        error=-EBADF; goto error_release;
       }
-     clo->offsets = vmalloc(sizeof(loff_t) * total_offsets);
+     clo->offsets = cloop_malloc(sizeof(loff_t) * total_offsets);
      if (!clo->offsets)
       {
        printk(KERN_ERR "%s: out of kernel mem for offsets\n", cloop_name);
@@ -598,18 +582,18 @@
    for(i=0;i<total_offsets-1;i++)
     {
      loff_t d=be64_to_cpu(clo->offsets[i+1]) - be64_to_cpu(clo->offsets[i]);
-     largest_block=MAX(largest_block,d);
+     clo->largest_block=MAX(clo->largest_block,d);
     }
    printk(KERN_INFO "%s: %s: %u blocks, %u bytes/block, largest block is %lu bytes.\n",
           cloop_name, filename, ntohl(clo->head.num_blocks),
-          ntohl(clo->head.block_size), largest_block);
+          ntohl(clo->head.block_size), clo->largest_block);
   }
 /* Combo kmalloc used too large chunks (>130000). */
  {
   int i;
   for(i=0;i<BUFFERED_BLOCKS;i++)
    {
-    clo->buffer[i] = vmalloc(ntohl(clo->head.block_size));
+    clo->buffer[i] = cloop_malloc(ntohl(clo->head.block_size));
     if(!clo->buffer[i])
      {
       printk(KERN_ERR "%s: out of memory for buffer %lu\n",
@@ -618,14 +602,14 @@
      }
    }
  }
- clo->compressed_buffer = vmalloc(largest_block);
+ clo->compressed_buffer = cloop_malloc(clo->largest_block);
  if(!clo->compressed_buffer)
   {
    printk(KERN_ERR "%s: out of memory for compressed buffer %lu\n",
-          cloop_name, largest_block);
+          cloop_name, clo->largest_block);
    error=-ENOMEM; goto error_release_free_buffer;
   }
- clo->zstream.workspace = vmalloc(zlib_inflate_workspacesize());
+ clo->zstream.workspace = cloop_malloc(zlib_inflate_workspacesize());
  if(!clo->zstream.workspace)
   {
    printk(KERN_ERR "%s: out of mem for zlib working area %u\n",
@@ -640,7 +624,7 @@
           cloop_name,
           be64_to_cpu(clo->offsets[ntohl(clo->head.num_blocks)]),
           inode->i_size);
-   vfree(clo->zstream.workspace); clo->zstream.workspace=NULL;
+   cloop_free(clo->zstream.workspace, zlib_inflate_workspacesize()); clo->zstream.workspace=NULL;
    goto error_release_free_all;
   }
  {
@@ -659,9 +643,9 @@
   }
  if(preload > 0)
   {
-   size_t preload_size = ((preload<=ntohl(clo->head.num_blocks))?preload:ntohl(clo->head.num_blocks))
+   clo->preload_size = ((preload<=ntohl(clo->head.num_blocks))?preload:ntohl(clo->head.num_blocks))
                           * ntohl(clo->head.block_size);
-   if((clo->preload_cache = vmalloc(preload_size)) != NULL)
+   if((clo->preload_cache = cloop_malloc(clo->preload_size)) != NULL)
     {
      int i;
      for(i=0; i<preload && i<ntohl(clo->head.num_blocks); i++)
@@ -674,7 +658,7 @@
        else
         {
          printk(KERN_WARNING "%s: can't read block %d into preload cache, ignored.\n", cloop_name, i);
-	 vfree(clo->preload_cache);
+	 cloop_free(clo->preload_cache, clo->preload_size);
 	 clo->preload_cache = NULL;
 	 break;
 	}
@@ -686,7 +670,7 @@
  /* Uncheck */
  return error;
 error_release_free_all:
- vfree(clo->compressed_buffer);
+ cloop_free(clo->compressed_buffer, clo->largest_block);
  clo->compressed_buffer=NULL;
 error_release_free_buffer:
  {
@@ -695,16 +679,16 @@
    { 
     if(clo->buffer[i])
      {
-      vfree(clo->buffer[i]);
+      cloop_free(clo->buffer[i], ntohl(clo->head.block_size));
       clo->buffer[i]=NULL;
      }
    }
  }
 error_release_free:
- vfree(clo->offsets);
+ cloop_free(clo->offsets, sizeof(loff_t) * total_offsets);
  clo->offsets=NULL;
 error_release:
- if(bbuf) vfree(bbuf);
+ if(bbuf) cloop_free(bbuf, clo->underlying_blksize);
  clo->backing_file=NULL;
  return error;
 }
@@ -740,13 +724,13 @@
  else { filp_close(initial_file,0); initial_file=NULL; }
  clo->backing_file  = NULL;
  clo->backing_inode = NULL;
- if(clo->offsets) { vfree(clo->offsets); clo->offsets = NULL; }
- if(clo->preload_cache) { vfree(clo->preload_cache); clo->preload_cache = NULL; }
+ if(clo->offsets) { cloop_free(clo->offsets, clo->underlying_blksize); clo->offsets = NULL; }
+ if(clo->preload_cache) { cloop_free(clo->preload_cache, clo->preload_size); clo->preload_cache = NULL; }
  for(i=0; i<BUFFERED_BLOCKS; i++)
-      if(clo->buffer[i]) { vfree(clo->buffer[i]); clo->buffer[i]=NULL; }
- if(clo->compressed_buffer) { vfree(clo->compressed_buffer); clo->compressed_buffer = NULL; }
+      if(clo->buffer[i]) { cloop_free(clo->buffer[i], ntohl(clo->head.block_size)); clo->buffer[i]=NULL; }
+ if(clo->compressed_buffer) { cloop_free(clo->compressed_buffer, clo->largest_block); clo->compressed_buffer = NULL; }
  zlib_inflateEnd(&clo->zstream);
- if(clo->zstream.workspace) { vfree(clo->zstream.workspace); clo->zstream.workspace = NULL; }
+ if(clo->zstream.workspace) { cloop_free(clo->zstream.workspace, zlib_inflate_workspacesize()); clo->zstream.workspace = NULL; }
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
  if(bdev) invalidate_bdev(bdev, 0);
 #else