kvm: Improve upgrade notes when facing unsupported kernels

[qemu] / block / qcow2.c

diff --git a/block/qcow2.c b/block/qcow2.c
index ba946e6..c2be42e 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1246,6 +1246,19 @@ typedef struct QCowAIOCB {
     QCowL2Meta l2meta;
 } QCowAIOCB;
 
+static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
+{
+    QCowAIOCB *acb = (QCowAIOCB *)blockacb;
+    if (acb->hd_aiocb)
+        bdrv_aio_cancel(acb->hd_aiocb);
+    qemu_aio_release(acb);
+}
+
+static AIOPool qcow_aio_pool = {
+    .aiocb_size         = sizeof(QCowAIOCB),
+    .cancel             = qcow_aio_cancel,
+};
+
 static void qcow_aio_read_cb(void *opaque, int ret);
 static void qcow_aio_read_bh(void *opaque)
 {
@@ -1375,7 +1388,7 @@ static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
 {
     QCowAIOCB *acb;
 
-    acb = qemu_aio_get(bs, cb, opaque);
+    acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque);
     if (!acb)
         return NULL;
     acb->hd_aiocb = NULL;
@@ -1498,14 +1511,6 @@ static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
     return &acb->common;
 }
 
-static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
-{
-    QCowAIOCB *acb = (QCowAIOCB *)blockacb;
-    if (acb->hd_aiocb)
-        bdrv_aio_cancel(acb->hd_aiocb);
-    qemu_aio_release(acb);
-}
-
 static void qcow_close(BlockDriverState *bs)
 {
     BDRVQcowState *s = bs->opaque;
@@ -2578,6 +2583,9 @@ static int update_refcount(BlockDriverState *bs,
 {
     BDRVQcowState *s = bs->opaque;
     int64_t start, last, cluster_offset;
+    int64_t refcount_block_offset = 0;
+    int64_t table_index = -1, old_table_index;
+    int first_index = -1, last_index = -1;
 
 #ifdef DEBUG_ALLOC2
     printf("update_refcount: offset=%lld size=%lld addend=%d\n",
@@ -2590,10 +2598,25 @@ static int update_refcount(BlockDriverState *bs,
     for(cluster_offset = start; cluster_offset <= last;
         cluster_offset += s->cluster_size)
     {
-        int64_t refcount_block_offset;
         int block_index, refcount;
         int64_t cluster_index = cluster_offset >> s->cluster_bits;
 
+        /* Only write refcount block to disk when we are done with it */
+        old_table_index = table_index;
+        table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
+        if ((old_table_index >= 0) && (table_index != old_table_index)) {
+            size_t size = (last_index - first_index + 1) << REFCOUNT_SHIFT;
+            if (bdrv_pwrite(s->hd,
+                refcount_block_offset + (first_index << REFCOUNT_SHIFT),
+                &s->refcount_block_cache[first_index], size) != size)
+            {
+                return -EIO;
+            }
+
+            first_index = -1;
+            last_index = -1;
+        }
+
         /* Load the refcount block and allocate it if needed */
         refcount_block_offset = alloc_refcount_block(bs, cluster_index);
         if (refcount_block_offset < 0) {
@@ -2603,6 +2626,13 @@ static int update_refcount(BlockDriverState *bs,
         /* we can update the count and save it */
         block_index = cluster_index &
             ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
+        if (first_index == -1 || block_index < first_index) {
+            first_index = block_index;
+        }
+        if (block_index > last_index) {
+            last_index = block_index;
+        }
+
         refcount = be16_to_cpu(s->refcount_block_cache[block_index]);
         refcount += addend;
         if (refcount < 0 || refcount > 0xffff)
@@ -2611,12 +2641,19 @@ static int update_refcount(BlockDriverState *bs,
             s->free_cluster_index = cluster_index;
         }
         s->refcount_block_cache[block_index] = cpu_to_be16(refcount);
+    }
+
+    /* Write last changed block to disk */
+    if (refcount_block_offset != 0) {
+        size_t size = (last_index - first_index + 1) << REFCOUNT_SHIFT;
         if (bdrv_pwrite(s->hd,
-                        refcount_block_offset + (block_index << REFCOUNT_SHIFT),
-                        &s->refcount_block_cache[block_index], 2) != 2)
+            refcount_block_offset + (first_index << REFCOUNT_SHIFT),
+            &s->refcount_block_cache[first_index], size) != size)
+        {
             return -EIO;
-
+        }
     }
+
     return 0;
 }
 
@@ -2944,11 +2981,31 @@ static int qcow_get_buffer(BlockDriverState *bs, uint8_t *buf,
 }
 
 static QEMUOptionParameter qcow_create_options[] = {
-    { BLOCK_OPT_SIZE,           OPT_SIZE },
-    { BLOCK_OPT_BACKING_FILE,   OPT_STRING },
-    { BLOCK_OPT_BACKING_FMT,    OPT_STRING },
-    { BLOCK_OPT_ENCRYPT,        OPT_FLAG },
-    { BLOCK_OPT_CLUSTER_SIZE,   OPT_SIZE },
+    {
+        .name = BLOCK_OPT_SIZE,
+        .type = OPT_SIZE,
+        .help = "Virtual disk size"
+    },
+    {
+        .name = BLOCK_OPT_BACKING_FILE,
+        .type = OPT_STRING,
+        .help = "File name of a base image"
+    },
+    {
+        .name = BLOCK_OPT_BACKING_FMT,
+        .type = OPT_STRING,
+        .help = "Image format of the base image"
+    },
+    {
+        .name = BLOCK_OPT_ENCRYPT,
+        .type = OPT_FLAG,
+        .help = "Encrypt the image"
+    },
+    {
+        .name = BLOCK_OPT_CLUSTER_SIZE,
+        .type = OPT_SIZE,
+        .help = "qcow2 cluster size"
+    },
     { NULL }
 };
 
@@ -2966,8 +3023,6 @@ static BlockDriver bdrv_qcow2 = {
 
     .bdrv_aio_readv    = qcow_aio_readv,
     .bdrv_aio_writev   = qcow_aio_writev,
-    .bdrv_aio_cancel   = qcow_aio_cancel,
-    .aiocb_size                = sizeof(QCowAIOCB),
     .bdrv_write_compressed = qcow_write_compressed,
 
     .bdrv_snapshot_create = qcow_snapshot_create,