push down vector linearization to posix-aio-compat.c (Christoph Hellwig)
[qemu] / block.c
diff --git a/block.c b/block.c
index 4f5c311..8a78f14 100644 (file)
--- a/block.c
+++ b/block.c
@@ -51,13 +51,17 @@ typedef struct BlockDriverAIOCBSync {
     BlockDriverAIOCB common;
     QEMUBH *bh;
     int ret;
+    /* vector translation state */
+    QEMUIOVector *qiov;
+    uint8_t *bounce;
+    int is_write;
 } BlockDriverAIOCBSync;
 
-static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);
-static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);
 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
@@ -136,17 +140,18 @@ void path_combine(char *dest, int dest_size,
 
 static void bdrv_register(BlockDriver *bdrv)
 {
-    if (!bdrv->bdrv_aio_read) {
+    if (!bdrv->bdrv_aio_readv) {
         /* add AIO emulation layer */
-        bdrv->bdrv_aio_read = bdrv_aio_read_em;
-        bdrv->bdrv_aio_write = bdrv_aio_write_em;
+        bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
+        bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
         bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
         bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
-    } else if (!bdrv->bdrv_read && !bdrv->bdrv_pread) {
+    } else if (!bdrv->bdrv_read) {
         /* add synchronous IO emulation layer */
         bdrv->bdrv_read = bdrv_read_em;
         bdrv->bdrv_write = bdrv_write_em;
     }
+    aio_pool_init(&bdrv->aio_pool, bdrv->aiocb_size, bdrv->bdrv_aio_cancel);
     bdrv->next = first_drv;
     first_drv = bdrv;
 }
@@ -178,6 +183,20 @@ BlockDriver *bdrv_find_format(const char *format_name)
     return NULL;
 }
 
+int bdrv_create2(BlockDriver *drv,
+                const char *filename, int64_t size_in_sectors,
+                const char *backing_file, const char *backing_format,
+                int flags)
+{
+    if (drv->bdrv_create2)
+        return drv->bdrv_create2(filename, size_in_sectors, backing_file,
+                                 backing_format, flags);
+    if (drv->bdrv_create)
+        return drv->bdrv_create(filename, size_in_sectors, backing_file,
+                                flags);
+    return -ENOTSUP;
+}
+
 int bdrv_create(BlockDriver *drv,
                 const char *filename, int64_t size_in_sectors,
                 const char *backing_file, int flags)
@@ -354,7 +373,7 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
 
         /* if there is a backing file, use it */
         bs1 = bdrv_new("");
-        ret = bdrv_open(bs1, filename, 0);
+        ret = bdrv_open2(bs1, filename, 0, drv);
         if (ret < 0) {
             bdrv_delete(bs1);
             return ret;
@@ -375,12 +394,14 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
         else
             realpath(filename, backing_filename);
 
-        ret = bdrv_create(&bdrv_qcow2, tmp_filename,
-                          total_size, backing_filename, 0);
+        ret = bdrv_create2(&bdrv_qcow2, tmp_filename,
+                           total_size, backing_filename, 
+                           (drv ? drv->format_name : NULL), 0);
         if (ret < 0) {
             return ret;
         }
         filename = tmp_filename;
+        drv = &bdrv_qcow2;
         bs->is_temporary = 1;
     }
 
@@ -426,10 +447,14 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
 #endif
     if (bs->backing_file[0] != '\0') {
         /* if there is a backing file, use it */
+        BlockDriver *back_drv = NULL;
         bs->backing_hd = bdrv_new("");
         path_combine(backing_filename, sizeof(backing_filename),
                      filename, bs->backing_file);
-        ret = bdrv_open(bs->backing_hd, backing_filename, open_flags);
+        if (bs->backing_format[0] != '\0')
+            back_drv = bdrv_find_format(bs->backing_format);
+        ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
+                         back_drv);
         if (ret < 0) {
             bdrv_close(bs);
             return ret;
@@ -546,15 +571,7 @@ static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
                               int nb_sectors)
 {
-    int64_t offset;
-
-    /* Deal with byte accesses */
-    if (sector_num < 0)
-        offset = -sector_num;
-    else
-        offset = sector_num * 512;
-
-    return bdrv_check_byte_request(bs, offset, nb_sectors * 512);
+    return bdrv_check_byte_request(bs, sector_num * 512, nb_sectors * 512);
 }
 
 /* return < 0 if error. See bdrv_write() for the return codes */
@@ -568,22 +585,7 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num,
     if (bdrv_check_request(bs, sector_num, nb_sectors))
         return -EIO;
 
-    if (drv->bdrv_pread) {
-        int ret, len;
-        len = nb_sectors * 512;
-        ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
-        if (ret < 0)
-            return ret;
-        else if (ret != len)
-            return -EINVAL;
-        else {
-           bs->rd_bytes += (unsigned) len;
-           bs->rd_ops ++;
-            return 0;
-       }
-    } else {
-        return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
-    }
+    return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 }
 
 /* Return < 0 if error. Important errors are:
@@ -603,27 +605,11 @@ int bdrv_write(BlockDriverState *bs, int64_t sector_num,
     if (bdrv_check_request(bs, sector_num, nb_sectors))
         return -EIO;
 
-    if (drv->bdrv_pwrite) {
-        int ret, len, count = 0;
-        len = nb_sectors * 512;
-        do {
-            ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len - count);
-            if (ret < 0) {
-                printf("bdrv_write ret=%d\n", ret);
-                return ret;
-            }
-            count += ret;
-            buf += ret;
-        } while (count != len);
-        bs->wr_bytes += (unsigned) len;
-        bs->wr_ops ++;
-        return 0;
-    }
     return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 }
 
-static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
-                         uint8_t *buf, int count1)
+int bdrv_pread(BlockDriverState *bs, int64_t offset,
+               void *buf, int count1)
 {
     uint8_t tmp_buf[SECTOR_SIZE];
     int len, nb_sectors, count;
@@ -666,8 +652,8 @@ static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
     return count1;
 }
 
-static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
-                          const uint8_t *buf, int count1)
+int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
+                const void *buf, int count1)
 {
     uint8_t tmp_buf[SECTOR_SIZE];
     int len, nb_sectors, count;
@@ -715,42 +701,6 @@ static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
 }
 
 /**
- * Read with byte offsets (needed only for file protocols)
- */
-int bdrv_pread(BlockDriverState *bs, int64_t offset,
-               void *buf1, int count1)
-{
-    BlockDriver *drv = bs->drv;
-
-    if (!drv)
-        return -ENOMEDIUM;
-    if (bdrv_check_byte_request(bs, offset, count1))
-        return -EIO;
-
-    if (!drv->bdrv_pread)
-        return bdrv_pread_em(bs, offset, buf1, count1);
-    return drv->bdrv_pread(bs, offset, buf1, count1);
-}
-
-/**
- * Write with byte offsets (needed only for file protocols)
- */
-int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
-                const void *buf1, int count1)
-{
-    BlockDriver *drv = bs->drv;
-
-    if (!drv)
-        return -ENOMEDIUM;
-    if (bdrv_check_byte_request(bs, offset, count1))
-        return -EIO;
-
-    if (!drv->bdrv_pwrite)
-        return bdrv_pwrite_em(bs, offset, buf1, count1);
-    return drv->bdrv_pwrite(bs, offset, buf1, count1);
-}
-
-/**
  * Truncate file to 'offset' bytes (needed only for file protocols)
  */
 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
@@ -1054,6 +1004,8 @@ const char *bdrv_get_device_name(BlockDriverState *bs)
 
 void bdrv_flush(BlockDriverState *bs)
 {
+    if (!bs->drv)
+        return;
     if (bs->drv->bdrv_flush)
         bs->drv->bdrv_flush(bs);
     if (bs->backing_hd)
@@ -1140,7 +1092,6 @@ void bdrv_info(Monitor *mon)
 void bdrv_info_stats(Monitor *mon)
 {
     BlockDriverState *bs;
-    BlockDriverInfo bdi;
 
     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
         monitor_printf(mon, "%s:"
@@ -1148,14 +1099,10 @@ void bdrv_info_stats(Monitor *mon)
                        " wr_bytes=%" PRIu64
                        " rd_operations=%" PRIu64
                        " wr_operations=%" PRIu64
-                       ,
+                       "\n",
                        bs->device_name,
                        bs->rd_bytes, bs->wr_bytes,
                        bs->rd_ops, bs->wr_ops);
-        if (bdrv_get_info(bs, &bdi) == 0)
-            monitor_printf(mon, " high=%" PRId64,
-                           bdi.highest_alloc);
-        monitor_printf(mon, "\n");
     }
 }
 
@@ -1201,6 +1148,26 @@ int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
     return drv->bdrv_get_info(bs, bdi);
 }
 
+int bdrv_put_buffer(BlockDriverState *bs, const uint8_t *buf, int64_t pos, int size)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_put_buffer)
+        return -ENOTSUP;
+    return drv->bdrv_put_buffer(bs, buf, pos, size);
+}
+
+int bdrv_get_buffer(BlockDriverState *bs, uint8_t *buf, int64_t pos, int size)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_get_buffer)
+        return -ENOTSUP;
+    return drv->bdrv_get_buffer(bs, buf, pos, size);
+}
+
 /**************************************************************/
 /* handling of snapshots */
 
@@ -1324,79 +1291,10 @@ char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
 /**************************************************************/
 /* async I/Os */
 
-typedef struct VectorTranslationState {
-    QEMUIOVector *iov;
-    uint8_t *bounce;
-    int is_write;
-    BlockDriverAIOCB *aiocb;
-    BlockDriverAIOCB *this_aiocb;
-} VectorTranslationState;
-
-static void bdrv_aio_rw_vector_cb(void *opaque, int ret)
-{
-    VectorTranslationState *s = opaque;
-
-    if (!s->is_write) {
-        qemu_iovec_from_buffer(s->iov, s->bounce, s->iov->size);
-    }
-    qemu_vfree(s->bounce);
-    s->this_aiocb->cb(s->this_aiocb->opaque, ret);
-    qemu_aio_release(s->this_aiocb);
-}
-
-static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
-                                            int64_t sector_num,
-                                            QEMUIOVector *iov,
-                                            int nb_sectors,
-                                            BlockDriverCompletionFunc *cb,
-                                            void *opaque,
-                                            int is_write)
-
-{
-    VectorTranslationState *s = qemu_mallocz(sizeof(*s));
-    BlockDriverAIOCB *aiocb = qemu_aio_get(bs, cb, opaque);
-
-    s->this_aiocb = aiocb;
-    s->iov = iov;
-    s->bounce = qemu_memalign(512, nb_sectors * 512);
-    s->is_write = is_write;
-    if (is_write) {
-        qemu_iovec_to_buffer(s->iov, s->bounce);
-        s->aiocb = bdrv_aio_write(bs, sector_num, s->bounce, nb_sectors,
-                                  bdrv_aio_rw_vector_cb, s);
-    } else {
-        s->aiocb = bdrv_aio_read(bs, sector_num, s->bounce, nb_sectors,
-                                 bdrv_aio_rw_vector_cb, s);
-    }
-    return aiocb;
-}
-
 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
-                                 QEMUIOVector *iov, int nb_sectors,
+                                 QEMUIOVector *qiov, int nb_sectors,
                                  BlockDriverCompletionFunc *cb, void *opaque)
 {
-    if (bdrv_check_request(bs, sector_num, nb_sectors))
-        return NULL;
-
-    return bdrv_aio_rw_vector(bs, sector_num, iov, nb_sectors,
-                              cb, opaque, 0);
-}
-
-BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
-                                  QEMUIOVector *iov, int nb_sectors,
-                                  BlockDriverCompletionFunc *cb, void *opaque)
-{
-    if (bdrv_check_request(bs, sector_num, nb_sectors))
-        return NULL;
-
-    return bdrv_aio_rw_vector(bs, sector_num, iov, nb_sectors,
-                              cb, opaque, 1);
-}
-
-BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
-                                uint8_t *buf, int nb_sectors,
-                                BlockDriverCompletionFunc *cb, void *opaque)
-{
     BlockDriver *drv = bs->drv;
     BlockDriverAIOCB *ret;
 
@@ -1405,7 +1303,8 @@ BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
     if (bdrv_check_request(bs, sector_num, nb_sectors))
         return NULL;
 
-    ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
+    ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
+                              cb, opaque);
 
     if (ret) {
        /* Update stats even though technically transfer has not happened. */
@@ -1416,9 +1315,9 @@ BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
     return ret;
 }
 
-BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
-                                 const uint8_t *buf, int nb_sectors,
-                                 BlockDriverCompletionFunc *cb, void *opaque)
+BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
+                                  QEMUIOVector *qiov, int nb_sectors,
+                                  BlockDriverCompletionFunc *cb, void *opaque)
 {
     BlockDriver *drv = bs->drv;
     BlockDriverAIOCB *ret;
@@ -1430,7 +1329,8 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
     if (bdrv_check_request(bs, sector_num, nb_sectors))
         return NULL;
 
-    ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
+    ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
+                               cb, opaque);
 
     if (ret) {
        /* Update stats even though technically transfer has not happened. */
@@ -1443,14 +1343,7 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
 
 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
 {
-    BlockDriver *drv = acb->bs->drv;
-
-    if (acb->cb == bdrv_aio_rw_vector_cb) {
-        VectorTranslationState *s = acb->opaque;
-        acb = s->aiocb;
-    }
-
-    drv->bdrv_aio_cancel(acb);
+    acb->pool->cancel(acb);
 }
 
 
@@ -1460,42 +1353,62 @@ void bdrv_aio_cancel(BlockDriverAIOCB *acb)
 static void bdrv_aio_bh_cb(void *opaque)
 {
     BlockDriverAIOCBSync *acb = opaque;
+
+    qemu_vfree(acb->bounce);
+
+    if (!acb->is_write)
+        qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
     acb->common.cb(acb->common.opaque, acb->ret);
+
     qemu_aio_release(acb);
 }
 
-static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
+                                            int64_t sector_num,
+                                            QEMUIOVector *qiov,
+                                            int nb_sectors,
+                                            BlockDriverCompletionFunc *cb,
+                                            void *opaque,
+                                            int is_write)
+
 {
     BlockDriverAIOCBSync *acb;
-    int ret;
 
     acb = qemu_aio_get(bs, cb, opaque);
+    acb->is_write = is_write;
+    acb->qiov = qiov;
+    acb->bounce = qemu_memalign(512, qiov->size);
+
     if (!acb->bh)
         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
-    ret = bdrv_read(bs, sector_num, buf, nb_sectors);
-    acb->ret = ret;
+
+    if (is_write) {
+        qemu_iovec_to_buffer(acb->qiov, acb->bounce);
+        acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
+    } else {
+        acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
+    }
+
     qemu_bh_schedule(acb->bh);
+
     return &acb->common;
 }
 
-static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
-    BlockDriverAIOCBSync *acb;
-    int ret;
+    return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+}
 
-    acb = qemu_aio_get(bs, cb, opaque);
-    if (!acb->bh)
-        acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
-    ret = bdrv_write(bs, sector_num, buf, nb_sectors);
-    acb->ret = ret;
-    qemu_bh_schedule(acb->bh);
-    return &acb->common;
+static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+        BlockDriverCompletionFunc *cb, void *opaque)
+{
+    return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
 }
 
+
 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
 {
     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
@@ -1518,10 +1431,15 @@ static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
 {
     int async_ret;
     BlockDriverAIOCB *acb;
+    struct iovec iov;
+    QEMUIOVector qiov;
 
     async_ret = NOT_DONE;
-    acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
-                        bdrv_rw_em_cb, &async_ret);
+    iov.iov_base = buf;
+    iov.iov_len = nb_sectors * 512;
+    qemu_iovec_init_external(&qiov, &iov, 1);
+    acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
+        bdrv_rw_em_cb, &async_ret);
     if (acb == NULL)
         return -1;
 
@@ -1537,10 +1455,15 @@ static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
 {
     int async_ret;
     BlockDriverAIOCB *acb;
+    struct iovec iov;
+    QEMUIOVector qiov;
 
     async_ret = NOT_DONE;
-    acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
-                         bdrv_rw_em_cb, &async_ret);
+    iov.iov_base = (void *)buf;
+    iov.iov_len = nb_sectors * 512;
+    qemu_iovec_init_external(&qiov, &iov, 1);
+    acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
+        bdrv_rw_em_cb, &async_ret);
     if (acb == NULL)
         return -1;
     while (async_ret == NOT_DONE) {
@@ -1568,18 +1491,25 @@ void bdrv_init(void)
     bdrv_register(&bdrv_nbd);
 }
 
-void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
-                   void *opaque)
+void aio_pool_init(AIOPool *pool, int aiocb_size,
+                   void (*cancel)(BlockDriverAIOCB *acb))
+{
+    pool->aiocb_size = aiocb_size;
+    pool->cancel = cancel;
+    pool->free_aiocb = NULL;
+}
+
+void *qemu_aio_get_pool(AIOPool *pool, BlockDriverState *bs,
+                        BlockDriverCompletionFunc *cb, void *opaque)
 {
-    BlockDriver *drv;
     BlockDriverAIOCB *acb;
 
-    drv = bs->drv;
-    if (drv->free_aiocb) {
-        acb = drv->free_aiocb;
-        drv->free_aiocb = acb->next;
+    if (pool->free_aiocb) {
+        acb = pool->free_aiocb;
+        pool->free_aiocb = acb->next;
     } else {
-        acb = qemu_mallocz(drv->aiocb_size);
+        acb = qemu_mallocz(pool->aiocb_size);
+        acb->pool = pool;
     }
     acb->bs = bs;
     acb->cb = cb;
@@ -1587,12 +1517,18 @@ void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
     return acb;
 }
 
+void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
+                   void *opaque)
+{
+    return qemu_aio_get_pool(&bs->drv->aio_pool, bs, cb, opaque);
+}
+
 void qemu_aio_release(void *p)
 {
-    BlockDriverAIOCB *acb = p;
-    BlockDriver *drv = acb->bs->drv;
-    acb->next = drv->free_aiocb;
-    drv->free_aiocb = acb;
+    BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
+    AIOPool *pool = acb->pool;
+    acb->next = pool->free_aiocb;
+    pool->free_aiocb = acb;
 }
 
 /**************************************************************/
@@ -1680,3 +1616,14 @@ int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
         return drv->bdrv_ioctl(bs, req, buf);
     return -ENOTSUP;
 }
+
+BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
+        unsigned long int req, void *buf,
+        BlockDriverCompletionFunc *cb, void *opaque)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (drv && drv->bdrv_aio_ioctl)
+        return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
+    return NULL;
+}