]> git.proxmox.com Git - qemu.git/blobdiff - block.c
Merge remote-tracking branch 'mjt/mjt-iov2' into staging
[qemu.git] / block.c
diff --git a/block.c b/block.c
index 754a422a6323d359360ebfd8cc1afe2bdb3a5478..0c923f2ae9c93716aff33bb45947f63a7ad30a2e 100644 (file)
--- a/block.c
+++ b/block.c
@@ -198,33 +198,31 @@ static void bdrv_io_limits_intercept(BlockDriverState *bs,
 /* check if the path starts with "<protocol>:" */
 static int path_has_protocol(const char *path)
 {
+    const char *p;
+
 #ifdef _WIN32
     if (is_windows_drive(path) ||
         is_windows_drive_prefix(path)) {
         return 0;
     }
+    p = path + strcspn(path, ":/\\");
+#else
+    p = path + strcspn(path, ":/");
 #endif
 
-    return strchr(path, ':') != NULL;
+    return *p == ':';
 }
 
 int path_is_absolute(const char *path)
 {
-    const char *p;
 #ifdef _WIN32
     /* specific case for names like: "\\.\d:" */
-    if (*path == '/' || *path == '\\')
+    if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
         return 1;
-#endif
-    p = strchr(path, ':');
-    if (p)
-        p++;
-    else
-        p = path;
-#ifdef _WIN32
-    return (*p == '/' || *p == '\\');
+    }
+    return (*path == '/' || *path == '\\');
 #else
-    return (*p == '/');
+    return (*path == '/');
 #endif
 }
 
@@ -272,6 +270,15 @@ void path_combine(char *dest, int dest_size,
     }
 }
 
+void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz)
+{
+    if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) {
+        pstrcpy(dest, sz, bs->backing_file);
+    } else {
+        path_combine(dest, sz, bs->filename, bs->backing_file);
+    }
+}
+
 void bdrv_register(BlockDriver *bdrv)
 {
     /* Block drivers without coroutine functions need emulation */
@@ -402,28 +409,36 @@ int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
     return bdrv_create(drv, filename, options);
 }
 
-#ifdef _WIN32
-void get_tmp_filename(char *filename, int size)
+/*
+ * Create a uniquely-named empty temporary file.
+ * Return 0 upon success, otherwise a negative errno value.
+ */
+int get_tmp_filename(char *filename, int size)
 {
+#ifdef _WIN32
     char temp_dir[MAX_PATH];
-
-    GetTempPath(MAX_PATH, temp_dir);
-    GetTempFileName(temp_dir, "qem", 0, filename);
-}
+    /* GetTempFileName requires that its output buffer (4th param)
+       have length MAX_PATH or greater.  */
+    assert(size >= MAX_PATH);
+    return (GetTempPath(MAX_PATH, temp_dir)
+            && GetTempFileName(temp_dir, "qem", 0, filename)
+            ? 0 : -GetLastError());
 #else
-void get_tmp_filename(char *filename, int size)
-{
     int fd;
     const char *tmpdir;
-    /* XXX: race condition possible */
     tmpdir = getenv("TMPDIR");
     if (!tmpdir)
         tmpdir = "/tmp";
-    snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
+    if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
+        return -EOVERFLOW;
+    }
     fd = mkstemp(filename);
-    close(fd);
-}
+    if (fd < 0 || close(fd)) {
+        return -errno;
+    }
+    return 0;
 #endif
+}
 
 /*
  * Detect host devices. By convention, /dev/cdrom[N] is always
@@ -612,16 +627,11 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
     int ret, open_flags;
 
     assert(drv != NULL);
+    assert(bs->file == NULL);
 
     trace_bdrv_open_common(bs, filename, flags, drv->format_name);
 
-    bs->file = NULL;
-    bs->total_sectors = 0;
-    bs->encrypted = 0;
-    bs->valid_key = 0;
-    bs->sg = 0;
     bs->open_flags = flags;
-    bs->growable = 0;
     bs->buffer_alignment = 512;
 
     assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
@@ -630,7 +640,6 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
     }
 
     pstrcpy(bs->filename, sizeof(bs->filename), filename);
-    bs->backing_file[0] = '\0';
 
     if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
         return -ENOTSUP;
@@ -640,12 +649,13 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
     bs->opaque = g_malloc0(drv->instance_size);
 
     bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB);
+    open_flags = flags | BDRV_O_CACHE_WB;
 
     /*
      * Clear flags that are internal to the block layer before opening the
      * image.
      */
-    open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
+    open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
 
     /*
      * Snapshots should be writable.
@@ -752,7 +762,10 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
 
         bdrv_delete(bs1);
 
-        get_tmp_filename(tmp_filename, sizeof(tmp_filename));
+        ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename));
+        if (ret < 0) {
+            return ret;
+        }
 
         /* Real path is meaningless for protocols */
         if (is_protocol)
@@ -804,14 +817,8 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         BlockDriver *back_drv = NULL;
 
         bs->backing_hd = bdrv_new("");
-
-        if (path_has_protocol(bs->backing_file)) {
-            pstrcpy(backing_filename, sizeof(backing_filename),
-                    bs->backing_file);
-        } else {
-            path_combine(backing_filename, sizeof(backing_filename),
-                         filename, bs->backing_file);
-        }
+        bdrv_get_full_backing_filename(bs, backing_filename,
+                                       sizeof(backing_filename));
 
         if (bs->backing_format[0] != '\0') {
             back_drv = bdrv_find_format(bs->backing_format);
@@ -878,9 +885,17 @@ void bdrv_close(BlockDriverState *bs)
         bs->opaque = NULL;
         bs->drv = NULL;
         bs->copy_on_read = 0;
+        bs->backing_file[0] = '\0';
+        bs->backing_format[0] = '\0';
+        bs->total_sectors = 0;
+        bs->encrypted = 0;
+        bs->valid_key = 0;
+        bs->sg = 0;
+        bs->growable = 0;
 
         if (bs->file != NULL) {
-            bdrv_close(bs->file);
+            bdrv_delete(bs->file);
+            bs->file = NULL;
         }
 
         bdrv_dev_change_media_cb(bs, false);
@@ -949,94 +964,137 @@ void bdrv_make_anon(BlockDriverState *bs)
     bs->device_name[0] = '\0';
 }
 
+static void bdrv_rebind(BlockDriverState *bs)
+{
+    if (bs->drv && bs->drv->bdrv_rebind) {
+        bs->drv->bdrv_rebind(bs);
+    }
+}
+
+static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
+                                     BlockDriverState *bs_src)
+{
+    /* move some fields that need to stay attached to the device */
+    bs_dest->open_flags         = bs_src->open_flags;
+
+    /* dev info */
+    bs_dest->dev_ops            = bs_src->dev_ops;
+    bs_dest->dev_opaque         = bs_src->dev_opaque;
+    bs_dest->dev                = bs_src->dev;
+    bs_dest->buffer_alignment   = bs_src->buffer_alignment;
+    bs_dest->copy_on_read       = bs_src->copy_on_read;
+
+    bs_dest->enable_write_cache = bs_src->enable_write_cache;
+
+    /* i/o timing parameters */
+    bs_dest->slice_time         = bs_src->slice_time;
+    bs_dest->slice_start        = bs_src->slice_start;
+    bs_dest->slice_end          = bs_src->slice_end;
+    bs_dest->io_limits          = bs_src->io_limits;
+    bs_dest->io_base            = bs_src->io_base;
+    bs_dest->throttled_reqs     = bs_src->throttled_reqs;
+    bs_dest->block_timer        = bs_src->block_timer;
+    bs_dest->io_limits_enabled  = bs_src->io_limits_enabled;
+
+    /* geometry */
+    bs_dest->cyls               = bs_src->cyls;
+    bs_dest->heads              = bs_src->heads;
+    bs_dest->secs               = bs_src->secs;
+    bs_dest->translation        = bs_src->translation;
+
+    /* r/w error */
+    bs_dest->on_read_error      = bs_src->on_read_error;
+    bs_dest->on_write_error     = bs_src->on_write_error;
+
+    /* i/o status */
+    bs_dest->iostatus_enabled   = bs_src->iostatus_enabled;
+    bs_dest->iostatus           = bs_src->iostatus;
+
+    /* dirty bitmap */
+    bs_dest->dirty_count        = bs_src->dirty_count;
+    bs_dest->dirty_bitmap       = bs_src->dirty_bitmap;
+
+    /* job */
+    bs_dest->in_use             = bs_src->in_use;
+    bs_dest->job                = bs_src->job;
+
+    /* keep the same entry in bdrv_states */
+    pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name),
+            bs_src->device_name);
+    bs_dest->list = bs_src->list;
+}
+
 /*
- * Add new bs contents at the top of an image chain while the chain is
- * live, while keeping required fields on the top layer.
+ * Swap bs contents for two image chains while they are live,
+ * while keeping required fields on the BlockDriverState that is
+ * actually attached to a device.
  *
  * This will modify the BlockDriverState fields, and swap contents
- * between bs_new and bs_top. Both bs_new and bs_top are modified.
+ * between bs_new and bs_old. Both bs_new and bs_old are modified.
  *
  * bs_new is required to be anonymous.
  *
  * This function does not create any image files.
  */
-void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
+void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
 {
     BlockDriverState tmp;
 
-    /* bs_new must be anonymous */
+    /* bs_new must be anonymous and shouldn't have anything fancy enabled */
     assert(bs_new->device_name[0] == '\0');
+    assert(bs_new->dirty_bitmap == NULL);
+    assert(bs_new->job == NULL);
+    assert(bs_new->dev == NULL);
+    assert(bs_new->in_use == 0);
+    assert(bs_new->io_limits_enabled == false);
+    assert(bs_new->block_timer == NULL);
 
     tmp = *bs_new;
+    *bs_new = *bs_old;
+    *bs_old = tmp;
 
-    /* there are some fields that need to stay on the top layer: */
+    /* there are some fields that should not be swapped, move them back */
+    bdrv_move_feature_fields(&tmp, bs_old);
+    bdrv_move_feature_fields(bs_old, bs_new);
+    bdrv_move_feature_fields(bs_new, &tmp);
 
-    /* dev info */
-    tmp.dev_ops           = bs_top->dev_ops;
-    tmp.dev_opaque        = bs_top->dev_opaque;
-    tmp.dev               = bs_top->dev;
-    tmp.buffer_alignment  = bs_top->buffer_alignment;
-    tmp.copy_on_read      = bs_top->copy_on_read;
-
-    /* i/o timing parameters */
-    tmp.slice_time        = bs_top->slice_time;
-    tmp.slice_start       = bs_top->slice_start;
-    tmp.slice_end         = bs_top->slice_end;
-    tmp.io_limits         = bs_top->io_limits;
-    tmp.io_base           = bs_top->io_base;
-    tmp.throttled_reqs    = bs_top->throttled_reqs;
-    tmp.block_timer       = bs_top->block_timer;
-    tmp.io_limits_enabled = bs_top->io_limits_enabled;
-
-    /* geometry */
-    tmp.cyls              = bs_top->cyls;
-    tmp.heads             = bs_top->heads;
-    tmp.secs              = bs_top->secs;
-    tmp.translation       = bs_top->translation;
+    /* bs_new shouldn't be in bdrv_states even after the swap!  */
+    assert(bs_new->device_name[0] == '\0');
 
-    /* r/w error */
-    tmp.on_read_error     = bs_top->on_read_error;
-    tmp.on_write_error    = bs_top->on_write_error;
+    /* Check a few fields that should remain attached to the device */
+    assert(bs_new->dev == NULL);
+    assert(bs_new->job == NULL);
+    assert(bs_new->in_use == 0);
+    assert(bs_new->io_limits_enabled == false);
+    assert(bs_new->block_timer == NULL);
 
-    /* i/o status */
-    tmp.iostatus_enabled  = bs_top->iostatus_enabled;
-    tmp.iostatus          = bs_top->iostatus;
+    bdrv_rebind(bs_new);
+    bdrv_rebind(bs_old);
+}
 
-    /* keep the same entry in bdrv_states */
-    pstrcpy(tmp.device_name, sizeof(tmp.device_name), bs_top->device_name);
-    tmp.list = bs_top->list;
+/*
+ * Add new bs contents at the top of an image chain while the chain is
+ * live, while keeping required fields on the top layer.
+ *
+ * This will modify the BlockDriverState fields, and swap contents
+ * between bs_new and bs_top. Both bs_new and bs_top are modified.
+ *
+ * bs_new is required to be anonymous.
+ *
+ * This function does not create any image files.
+ */
+void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
+{
+    bdrv_swap(bs_new, bs_top);
 
     /* The contents of 'tmp' will become bs_top, as we are
      * swapping bs_new and bs_top contents. */
-    tmp.backing_hd = bs_new;
-    pstrcpy(tmp.backing_file, sizeof(tmp.backing_file), bs_top->filename);
-    bdrv_get_format(bs_top, tmp.backing_format, sizeof(tmp.backing_format));
-
-    /* swap contents of the fixed new bs and the current top */
-    *bs_new = *bs_top;
-    *bs_top = tmp;
-
-    /* device_name[] was carried over from the old bs_top.  bs_new
-     * shouldn't be in bdrv_states, so we need to make device_name[]
-     * reflect the anonymity of bs_new
-     */
-    bs_new->device_name[0] = '\0';
-
-    /* clear the copied fields in the new backing file */
-    bdrv_detach_dev(bs_new, bs_new->dev);
-
-    qemu_co_queue_init(&bs_new->throttled_reqs);
-    memset(&bs_new->io_base,   0, sizeof(bs_new->io_base));
-    memset(&bs_new->io_limits, 0, sizeof(bs_new->io_limits));
-    bdrv_iostatus_disable(bs_new);
-
-    /* we don't use bdrv_io_limits_disable() for this, because we don't want
-     * to affect or delete the block_timer, as it has been moved to bs_top */
-    bs_new->io_limits_enabled = false;
-    bs_new->block_timer       = NULL;
-    bs_new->slice_time        = 0;
-    bs_new->slice_start       = 0;
-    bs_new->slice_end         = 0;
+    bs_top->backing_hd = bs_new;
+    bs_top->open_flags &= ~BDRV_O_NO_BACKING;
+    pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file),
+            bs_new->filename);
+    pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format),
+            bs_new->drv ? bs_new->drv->format_name : "");
 }
 
 void bdrv_delete(BlockDriverState *bs)
@@ -1049,9 +1107,6 @@ void bdrv_delete(BlockDriverState *bs)
     bdrv_make_anon(bs);
 
     bdrv_close(bs);
-    if (bs->file != NULL) {
-        bdrv_delete(bs->file);
-    }
 
     assert(bs != bs_snapshots);
     g_free(bs);
@@ -1200,14 +1255,14 @@ bool bdrv_dev_is_medium_locked(BlockDriverState *bs)
  * free of errors) or -errno when an internal error occurred. The results of the
  * check are stored in res.
  */
-int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
+int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
 {
     if (bs->drv->bdrv_check == NULL) {
         return -ENOTSUP;
     }
 
     memset(res, 0, sizeof(*res));
-    return bs->drv->bdrv_check(bs, res);
+    return bs->drv->bdrv_check(bs, res, fix);
 }
 
 #define COMMIT_BUF_SECTORS 2048
@@ -1584,6 +1639,22 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num,
     return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false);
 }
 
+/* Just like bdrv_read(), but with I/O throttling temporarily disabled */
+int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,
+                          uint8_t *buf, int nb_sectors)
+{
+    bool enabled;
+    int ret;
+
+    enabled = bs->io_limits_enabled;
+    bs->io_limits_enabled = false;
+    ret = bdrv_read(bs, 0, buf, 1);
+    bs->io_limits_enabled = enabled;
+    return ret;
+}
+
+#define BITS_PER_LONG  (sizeof(unsigned long) * 8)
+
 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
                              int nb_sectors, int dirty)
 {
@@ -1594,8 +1665,8 @@ static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
     end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
 
     for (; start <= end; start++) {
-        idx = start / (sizeof(unsigned long) * 8);
-        bit = start % (sizeof(unsigned long) * 8);
+        idx = start / BITS_PER_LONG;
+        bit = start % BITS_PER_LONG;
         val = bs->dirty_bitmap[idx];
         if (dirty) {
             if (!(val & (1UL << bit))) {
@@ -1734,8 +1805,8 @@ int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
         return ret;
     }
 
-    /* No flush needed for cache modes that use O_DSYNC */
-    if ((bs->open_flags & BDRV_O_CACHE_WB) != 0) {
+    /* No flush needed for cache modes that already do it */
+    if (bs->enable_write_cache) {
         bdrv_flush(bs);
     }
 
@@ -1784,6 +1855,9 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
         ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num,
                                       cluster_nb_sectors);
     } else {
+        /* This does not change the data on the disk, it is not necessary
+         * to flush even in cache=writethrough mode.
+         */
         ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors,
                                   &bounce_qiov);
     }
@@ -1797,8 +1871,8 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
     }
 
     skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
-    qemu_iovec_from_buffer(qiov, bounce_buffer + skip_bytes,
-                           nb_sectors * BDRV_SECTOR_SIZE);
+    qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
+                        nb_sectors * BDRV_SECTOR_SIZE);
 
 err:
     qemu_vfree(bounce_buffer);
@@ -1953,6 +2027,10 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
         ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
     }
 
+    if (ret == 0 && !bs->enable_write_cache) {
+        ret = bdrv_co_flush(bs);
+    }
+
     if (bs->dirty_bitmap) {
         set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
     }
@@ -2072,11 +2150,10 @@ static int guess_disk_lchs(BlockDriverState *bs,
                            int *pcylinders, int *pheads, int *psectors)
 {
     uint8_t buf[BDRV_SECTOR_SIZE];
-    int ret, i, heads, sectors, cylinders;
+    int i, heads, sectors, cylinders;
     struct partition *p;
     uint32_t nr_sects;
     uint64_t nb_sectors;
-    bool enabled;
 
     bdrv_get_geometry(bs, &nb_sectors);
 
@@ -2085,12 +2162,9 @@ static int guess_disk_lchs(BlockDriverState *bs,
      * but also in async I/O mode. So the I/O throttling function has to
      * be disabled temporarily here, not permanently.
      */
-    enabled = bs->io_limits_enabled;
-    bs->io_limits_enabled = false;
-    ret = bdrv_read(bs, 0, buf, 1);
-    bs->io_limits_enabled = enabled;
-    if (ret < 0)
+    if (bdrv_read_unthrottled(bs, 0, buf, 1) < 0) {
         return -1;
+    }
     /* test msdos magic */
     if (buf[510] != 0x55 || buf[511] != 0xaa)
         return -1;
@@ -2273,46 +2347,40 @@ void bdrv_get_floppy_geometry_hint(BlockDriverState *bs, int *nb_heads,
     uint64_t nb_sectors, size;
     int i, first_match, match;
 
-    bdrv_get_geometry_hint(bs, nb_heads, max_track, last_sect);
-    if (*nb_heads != 0 && *max_track != 0 && *last_sect != 0) {
-        /* User defined disk */
-        *rate = FDRIVE_RATE_500K;
-    } else {
-        bdrv_get_geometry(bs, &nb_sectors);
-        match = -1;
-        first_match = -1;
-        for (i = 0; ; i++) {
-            parse = &fd_formats[i];
-            if (parse->drive == FDRIVE_DRV_NONE) {
+    bdrv_get_geometry(bs, &nb_sectors);
+    match = -1;
+    first_match = -1;
+    for (i = 0; ; i++) {
+        parse = &fd_formats[i];
+        if (parse->drive == FDRIVE_DRV_NONE) {
+            break;
+        }
+        if (drive_in == parse->drive ||
+            drive_in == FDRIVE_DRV_NONE) {
+            size = (parse->max_head + 1) * parse->max_track *
+                parse->last_sect;
+            if (nb_sectors == size) {
+                match = i;
                 break;
             }
-            if (drive_in == parse->drive ||
-                drive_in == FDRIVE_DRV_NONE) {
-                size = (parse->max_head + 1) * parse->max_track *
-                    parse->last_sect;
-                if (nb_sectors == size) {
-                    match = i;
-                    break;
-                }
-                if (first_match == -1) {
-                    first_match = i;
-                }
-            }
-        }
-        if (match == -1) {
             if (first_match == -1) {
-                match = 1;
-            } else {
-                match = first_match;
+                first_match = i;
             }
-            parse = &fd_formats[match];
         }
-        *nb_heads = parse->max_head + 1;
-        *max_track = parse->max_track;
-        *last_sect = parse->last_sect;
-        *drive = parse->drive;
-        *rate = parse->rate;
     }
+    if (match == -1) {
+        if (first_match == -1) {
+            match = 1;
+        } else {
+            match = first_match;
+        }
+        parse = &fd_formats[match];
+    }
+    *nb_heads = parse->max_head + 1;
+    *max_track = parse->max_track;
+    *last_sect = parse->last_sect;
+    *drive = parse->drive;
+    *rate = parse->rate;
 }
 
 int bdrv_get_translation_hint(BlockDriverState *bs)
@@ -2347,6 +2415,11 @@ int bdrv_enable_write_cache(BlockDriverState *bs)
     return bs->enable_write_cache;
 }
 
+void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce)
+{
+    bs->enable_write_cache = wce;
+}
+
 int bdrv_is_encrypted(BlockDriverState *bs)
 {
     if (bs->backing_hd && bs->backing_hd->encrypted)
@@ -2389,13 +2462,9 @@ int bdrv_set_key(BlockDriverState *bs, const char *key)
     return ret;
 }
 
-void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
+const char *bdrv_get_format_name(BlockDriverState *bs)
 {
-    if (!bs->drv) {
-        buf[0] = '\0';
-    } else {
-        pstrcpy(buf, buf_size, bs->drv->format_name);
-    }
+    return bs->drv ? bs->drv->format_name : NULL;
 }
 
 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
@@ -2442,6 +2511,11 @@ const char *bdrv_get_device_name(BlockDriverState *bs)
     return bs->device_name;
 }
 
+int bdrv_get_flags(BlockDriverState *bs)
+{
+    return bs->open_flags;
+}
+
 void bdrv_flush_all(void)
 {
     BlockDriverState *bs;
@@ -2545,6 +2619,55 @@ int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
     return data.ret;
 }
 
+/*
+ * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
+ *
+ * Return true if the given sector is allocated in any image between
+ * BASE and TOP (inclusive).  BASE can be NULL to check if the given
+ * sector is allocated in any image of the chain.  Return false otherwise.
+ *
+ * 'pnum' is set to the number of sectors (including and immediately following
+ *  the specified sector) that are known to be in the same
+ *  allocated/unallocated state.
+ *
+ */
+int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
+                                            BlockDriverState *base,
+                                            int64_t sector_num,
+                                            int nb_sectors, int *pnum)
+{
+    BlockDriverState *intermediate;
+    int ret, n = nb_sectors;
+
+    intermediate = top;
+    while (intermediate && intermediate != base) {
+        int pnum_inter;
+        ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors,
+                                   &pnum_inter);
+        if (ret < 0) {
+            return ret;
+        } else if (ret) {
+            *pnum = pnum_inter;
+            return 1;
+        }
+
+        /*
+         * [sector_num, nb_sectors] is unallocated on top but intermediate
+         * might have
+         *
+         * [sector_num+x, nr_sectors] allocated.
+         */
+        if (n > pnum_inter) {
+            n = pnum_inter;
+        }
+
+        intermediate = intermediate->backing_hd;
+    }
+
+    *pnum = n;
+    return 0;
+}
+
 BlockInfoList *qmp_query_block(Error **errp)
 {
     BlockInfoList *head = NULL, *cur_item = NULL;
@@ -3077,13 +3200,13 @@ static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
             // Add the first request to the merged one. If the requests are
             // overlapping, drop the last sectors of the first request.
             size = (reqs[i].sector - reqs[outidx].sector) << 9;
-            qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
+            qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size);
 
             // We should need to add any zeros between the two requests
             assert (reqs[i].sector <= oldreq_last);
 
             // Add the second request
-            qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
+            qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size);
 
             reqs[outidx].nb_sectors = qiov->size >> 9;
             reqs[outidx].qiov = qiov;
@@ -3358,7 +3481,7 @@ static void bdrv_aio_bh_cb(void *opaque)
     BlockDriverAIOCBSync *acb = opaque;
 
     if (!acb->is_write)
-        qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
+        qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
     qemu_vfree(acb->bounce);
     acb->common.cb(acb->common.opaque, acb->ret);
     qemu_bh_delete(acb->bh);
@@ -3384,7 +3507,7 @@ static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
     acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
 
     if (is_write) {
-        qemu_iovec_to_buffer(acb->qiov, acb->bounce);
+        qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
         acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
     } else {
         acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
@@ -3900,10 +4023,10 @@ void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
     if (enable) {
         if (!bs->dirty_bitmap) {
             bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
-                    BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
-            bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
+                    BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG - 1;
+            bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG;
 
-            bs->dirty_bitmap = g_malloc0(bitmap_size);
+            bs->dirty_bitmap = g_new0(unsigned long, bitmap_size);
         }
     } else {
         if (bs->dirty_bitmap) {
@@ -4175,6 +4298,7 @@ void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
     job->bs            = bs;
     job->cb            = cb;
     job->opaque        = opaque;
+    job->busy          = true;
     bs->job = job;
 
     /* Only set speed when necessary to avoid NotSupported error */
@@ -4224,6 +4348,9 @@ void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
 void block_job_cancel(BlockJob *job)
 {
     job->cancelled = true;
+    if (job->co && !job->busy) {
+        qemu_coroutine_enter(job->co, NULL);
+    }
 }
 
 bool block_job_is_cancelled(BlockJob *job)
@@ -4231,13 +4358,52 @@ bool block_job_is_cancelled(BlockJob *job)
     return job->cancelled;
 }
 
-void block_job_cancel_sync(BlockJob *job)
+struct BlockCancelData {
+    BlockJob *job;
+    BlockDriverCompletionFunc *cb;
+    void *opaque;
+    bool cancelled;
+    int ret;
+};
+
+static void block_job_cancel_cb(void *opaque, int ret)
 {
+    struct BlockCancelData *data = opaque;
+
+    data->cancelled = block_job_is_cancelled(data->job);
+    data->ret = ret;
+    data->cb(data->opaque, ret);
+}
+
+int block_job_cancel_sync(BlockJob *job)
+{
+    struct BlockCancelData data;
     BlockDriverState *bs = job->bs;
 
     assert(bs->job == job);
+
+    /* Set up our own callback to store the result and chain to
+     * the original callback.
+     */
+    data.job = job;
+    data.cb = job->cb;
+    data.opaque = job->opaque;
+    data.ret = -EINPROGRESS;
+    job->cb = block_job_cancel_cb;
+    job->opaque = &data;
     block_job_cancel(job);
-    while (bs->job != NULL && bs->job->busy) {
+    while (data.ret == -EINPROGRESS) {
         qemu_aio_wait();
     }
+    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
+}
+
+void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns)
+{
+    /* Check cancellation *before* setting busy = false, too!  */
+    if (!block_job_is_cancelled(job)) {
+        job->busy = false;
+        co_sleep_ns(clock, ns);
+        job->busy = true;
+    }
 }