[Qemu-devel] [6816] Revert r6404

[Anthony Liguori <anthony@codemonkey.ws>]

Revision: 6816
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6816
Author:   aliguori
Date:     2009-03-11 20:05:37 +0000 (Wed, 11 Mar 2009)
Log Message:
-----------
Revert r6404

This series is broken by design as it requires expensive IO operations at
open time causing very long delays when starting a virtual machine for the
first time.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Modified Paths:
--------------
    trunk/block-qcow2.c

Modified: trunk/block-qcow2.c
===================================================================
--- trunk/block-qcow2.c	2009-03-11 20:05:33 UTC (rev 6815)
+++ trunk/block-qcow2.c	2009-03-11 20:05:37 UTC (rev 6816)
@@ -143,9 +143,6 @@
     uint32_t crypt_method_header;
     AES_KEY aes_encrypt_key;
     AES_KEY aes_decrypt_key;
-
-    int64_t highest_alloc; /* highest cluester allocated (in clusters) */
-
     uint64_t snapshots_offset;
     int snapshots_size;
     int nb_snapshots;
@@ -173,9 +170,7 @@
 #ifdef DEBUG_ALLOC
 static void check_refcounts(BlockDriverState *bs);
 #endif
-static void scan_refcount(BlockDriverState *bs, int64_t *high);
 
-
 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
 {
     const QCowHeader *cow_header = (const void *)buf;
@@ -275,8 +270,6 @@
     if (refcount_init(bs) < 0)
         goto fail;
 
-    scan_refcount(bs, &s->highest_alloc);
-
     /* read the backing file name */
     if (header.backing_file_offset != 0) {
         len = header.backing_file_size;
@@ -2163,29 +2156,6 @@
     return 0;
 }
 
-static void scan_refcount(BlockDriverState *bs, int64_t *high)
-{
-    BDRVQcowState *s = bs->opaque;
-    int64_t refcnt_index, cluster_index, cluster_end, h = 0;
-
-    for (refcnt_index=0; refcnt_index < s->refcount_table_size; refcnt_index++){
-        if (s->refcount_table[refcnt_index] == 0) {
-            continue;
-        }
-        cluster_index = refcnt_index << (s->cluster_bits - REFCOUNT_SHIFT);
-        cluster_end = (refcnt_index + 1) << (s->cluster_bits - REFCOUNT_SHIFT);
-        for ( ; cluster_index < cluster_end; cluster_index++) {
-            if (get_refcount(bs, cluster_index) == 0)
-                /* do nothing -- reserved for free counting */;
-            else
-                h = cluster_index;
-        }
-    }
-
-    if (high)
-        *high = (h+1);
-}
-
 static int get_refcount(BlockDriverState *bs, int64_t cluster_index)
 {
     BDRVQcowState *s = bs->opaque;
@@ -2226,10 +2196,6 @@
             size,
             (s->free_cluster_index - nb_clusters) << s->cluster_bits);
 #endif
-
-    if (s->highest_alloc < s->free_cluster_index)
-        s->highest_alloc = s->free_cluster_index;
-
     return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
 }