qcow2: Finalise interface of handle_alloc()

[qemu.git] / block / qcow2.c

diff --git a/block/qcow2.c b/block/qcow2.c
index 205d910a52d018ce7e502d9dd9cd8ecb62111dd9..3f7edf56525797106ce8901cde0bb3a0746db0dd 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -23,12 +23,13 @@
  */
 #include "qemu-common.h"
 #include "block/block_int.h"
-#include "module.h"
+#include "qemu/module.h"
 #include <zlib.h>
 #include "block/aes.h"
 #include "block/qcow2.h"
-#include "qemu-error.h"
+#include "qemu/error-report.h"
 #include "qapi/qmp/qerror.h"
+#include "qapi/qmp/qbool.h"
 #include "trace.h"
 
 /*
@@ -285,11 +286,26 @@ static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
     return ret;
 }
 
-static int qcow2_open(BlockDriverState *bs, int flags)
+static QemuOptsList qcow2_runtime_opts = {
+    .name = "qcow2",
+    .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head),
+    .desc = {
+        {
+            .name = "lazy_refcounts",
+            .type = QEMU_OPT_BOOL,
+            .help = "Postpone refcount updates",
+        },
+        { /* end of list */ }
+    },
+};
+
+static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
 {
     BDRVQcowState *s = bs->opaque;
     int len, i, ret = 0;
     QCowHeader header;
+    QemuOpts *opts;
+    Error *local_err = NULL;
     uint64_t ext_end;
 
     ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
@@ -311,7 +327,7 @@ static int qcow2_open(BlockDriverState *bs, int flags)
     be32_to_cpus(&header.nb_snapshots);
 
     if (header.magic != QCOW_MAGIC) {
-        ret = -EINVAL;
+        ret = -EMEDIUMTYPE;
         goto fail;
     }
     if (header.version < 2 || header.version > 3) {
@@ -495,6 +511,28 @@ static int qcow2_open(BlockDriverState *bs, int flags)
         }
     }
 
+    /* Enable lazy_refcounts according to image and command line options */
+    opts = qemu_opts_create_nofail(&qcow2_runtime_opts);
+    qemu_opts_absorb_qdict(opts, options, &local_err);
+    if (error_is_set(&local_err)) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        ret = -EINVAL;
+        goto fail;
+    }
+
+    s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,
+        (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));
+
+    qemu_opts_del(opts);
+
+    if (s->use_lazy_refcounts && s->qcow_version < 3) {
+        qerror_report(ERROR_CLASS_GENERIC_ERROR, "Lazy refcounts require "
+            "a qcow2 image with at least qemu 1.1 compatibility level");
+        ret = -EINVAL;
+        goto fail;
+    }
+
 #ifdef DEBUG_ALLOC
     {
         BdrvCheckResult result = {0};
@@ -584,7 +622,7 @@ static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs,
         *pnum = 0;
     }
 
-    return (cluster_offset != 0);
+    return (cluster_offset != 0) || (ret == QCOW2_CLUSTER_ZERO);
 }
 
 /* handle reading after the end of the backing file */
@@ -665,10 +703,6 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
             break;
 
         case QCOW2_CLUSTER_ZERO:
-            if (s->qcow_version < 3) {
-                ret = -EIO;
-                goto fail;
-            }
             qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors);
             break;
 
@@ -759,7 +793,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
     QEMUIOVector hd_qiov;
     uint64_t bytes_done = 0;
     uint8_t *cluster_data = NULL;
-    QCowL2Meta *l2meta;
+    QCowL2Meta *l2meta = NULL;
 
     trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num,
                                  remaining_sectors);
@@ -835,9 +869,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
                 QLIST_REMOVE(l2meta, next_in_flight);
             }
 
-            qemu_co_mutex_unlock(&s->lock);
             qemu_co_queue_restart_all(&l2meta->dependent_requests);
-            qemu_co_mutex_lock(&s->lock);
 
             g_free(l2meta);
             l2meta = NULL;
@@ -897,6 +929,7 @@ static void qcow2_invalidate_cache(BlockDriverState *bs)
     AES_KEY aes_encrypt_key;
     AES_KEY aes_decrypt_key;
     uint32_t crypt_method = 0;
+    QDict *options;
 
     /*
      * Backing files are read-only which makes all of their metadata immutable,
@@ -911,8 +944,14 @@ static void qcow2_invalidate_cache(BlockDriverState *bs)
 
     qcow2_close(bs);
 
+    options = qdict_new();
+    qdict_put(options, QCOW2_OPT_LAZY_REFCOUNTS,
+              qbool_from_int(s->use_lazy_refcounts));
+
     memset(s, 0, sizeof(BDRVQcowState));
-    qcow2_open(bs, flags);
+    qcow2_open(bs, options, flags);
+
+    QDECREF(options);
 
     if (crypt_method) {
         s->crypt_method = crypt_method;
@@ -1213,7 +1252,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
         return ret;
     }
 
-    ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR);
+    ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR);
     if (ret < 0) {
         return ret;
     }
@@ -1265,7 +1304,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
      */
     BlockDriver* drv = bdrv_find_format("qcow2");
     assert(drv != NULL);
-    ret = bdrv_open(bs, filename,
+    ret = bdrv_open(bs, filename, NULL,
         BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv);
     if (ret < 0) {
         goto out;