blockjobs: split interface into public/private, Part 1

[mirror_qemu.git] / block / stream.c

diff --git a/block/stream.c b/block/stream.c
index 25af7eff62b43abb4d893903c29ecfee7b15ab92..b05856bd65492819055c55f28c6741580751c17a 100644 (file)
--- a/block/stream.c
+++ b/block/stream.c
@@ -11,9 +11,11 @@
  *
  */
 
+#include "qemu/osdep.h"
 #include "trace.h"
 #include "block/block_int.h"
-#include "block/blockjob.h"
+#include "block/blockjob_int.h"
+#include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/ratelimit.h"
 #include "sysemu/block-backend.h"
@@ -35,9 +37,10 @@ typedef struct StreamBlockJob {
     BlockDriverState *base;
     BlockdevOnError on_error;
     char *backing_file_str;
+    int bs_flags;
 } StreamBlockJob;
 
-static int coroutine_fn stream_populate(BlockDriverState *bs,
+static int coroutine_fn stream_populate(BlockBackend *blk,
                                         int64_t sector_num, int nb_sectors,
                                         void *buf)
 {
@@ -50,7 +53,8 @@ static int coroutine_fn stream_populate(BlockDriverState *bs,
     qemu_iovec_init_external(&qiov, &iov, 1);
 
     /* Copy-on-read the unallocated clusters */
-    return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov);
+    return blk_co_preadv(blk, sector_num * BDRV_SECTOR_SIZE, qiov.size, &qiov,
+                         BDRV_REQ_COPY_ON_READ);
 }
 
 typedef struct {
@@ -62,6 +66,7 @@ static void stream_complete(BlockJob *job, void *opaque)
 {
     StreamBlockJob *s = container_of(job, StreamBlockJob, common);
     StreamCompleteData *data = opaque;
+    BlockDriverState *bs = blk_bs(job->blk);
     BlockDriverState *base = s->base;
 
     if (!block_job_is_cancelled(&s->common) && data->reached_end &&
@@ -73,8 +78,13 @@ static void stream_complete(BlockJob *job, void *opaque)
                 base_fmt = base->drv->format_name;
             }
         }
-        data->ret = bdrv_change_backing_file(job->bs, base_id, base_fmt);
-        bdrv_set_backing_hd(job->bs, base);
+        data->ret = bdrv_change_backing_file(bs, base_id, base_fmt);
+        bdrv_set_backing_hd(bs, base);
+    }
+
+    /* Reopen the image back in read-only mode if necessary */
+    if (s->bs_flags != bdrv_get_flags(bs)) {
+        bdrv_reopen(bs, s->bs_flags, NULL);
     }
 
     g_free(s->backing_file_str);
@@ -86,23 +96,25 @@ static void coroutine_fn stream_run(void *opaque)
 {
     StreamBlockJob *s = opaque;
     StreamCompleteData *data;
-    BlockDriverState *bs = s->common.bs;
+    BlockBackend *blk = s->common.blk;
+    BlockDriverState *bs = blk_bs(blk);
     BlockDriverState *base = s->base;
-    int64_t sector_num, end;
+    int64_t sector_num = 0;
+    int64_t end = -1;
+    uint64_t delay_ns = 0;
     int error = 0;
     int ret = 0;
     int n = 0;
     void *buf;
 
     if (!bs->backing) {
-        block_job_completed(&s->common, 0);
-        return;
+        goto out;
     }
 
     s->common.len = bdrv_getlength(bs);
     if (s->common.len < 0) {
-        block_job_completed(&s->common, s->common.len);
-        return;
+        ret = s->common.len;
+        goto out;
     }
 
     end = s->common.len >> BDRV_SECTOR_BITS;
@@ -118,10 +130,8 @@ static void coroutine_fn stream_run(void *opaque)
     }
 
     for (sector_num = 0; sector_num < end; sector_num += n) {
-        uint64_t delay_ns = 0;
         bool copy;
 
-wait:
         /* Note that even when no rate limit is applied we need to yield
          * with no pending I/O here so that bdrv_drain_all() returns.
          */
@@ -151,18 +161,11 @@ wait:
         }
         trace_stream_one_iteration(s, sector_num, n, ret);
         if (copy) {
-            if (s->common.speed) {
-                delay_ns = ratelimit_calculate_delay(&s->limit, n);
-                if (delay_ns > 0) {
-                    goto wait;
-                }
-            }
-            ret = stream_populate(bs, sector_num, n, buf);
+            ret = stream_populate(blk, sector_num, n, buf);
         }
         if (ret < 0) {
             BlockErrorAction action =
-                block_job_error_action(&s->common, s->common.bs, s->on_error,
-                                       true, -ret);
+                block_job_error_action(&s->common, s->on_error, true, -ret);
             if (action == BLOCK_ERROR_ACTION_STOP) {
                 n = 0;
                 continue;
@@ -178,6 +181,9 @@ wait:
 
         /* Publish progress */
         s->common.offset += n * BDRV_SECTOR_SIZE;
+        if (copy && s->common.speed) {
+            delay_ns = ratelimit_calculate_delay(&s->limit, n);
+        }
     }
 
     if (!base) {
@@ -189,6 +195,7 @@ wait:
 
     qemu_vfree(buf);
 
+out:
     /* Modify backing chain and close BDSes in main loop */
     data = g_malloc(sizeof(*data));
     data->ret = ret;
@@ -213,31 +220,41 @@ static const BlockJobDriver stream_job_driver = {
     .set_speed     = stream_set_speed,
 };
 
-void stream_start(BlockDriverState *bs, BlockDriverState *base,
-                  const char *backing_file_str, int64_t speed,
-                  BlockdevOnError on_error,
-                  BlockCompletionFunc *cb,
-                  void *opaque, Error **errp)
+void stream_start(const char *job_id, BlockDriverState *bs,
+                  BlockDriverState *base, const char *backing_file_str,
+                  int64_t speed, BlockdevOnError on_error, Error **errp)
 {
     StreamBlockJob *s;
+    BlockDriverState *iter;
+    int orig_bs_flags;
 
-    if ((on_error == BLOCKDEV_ON_ERROR_STOP ||
-         on_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
-        (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) {
-        error_setg(errp, QERR_INVALID_PARAMETER, "on-error");
+    s = block_job_create(job_id, &stream_job_driver, bs, speed,
+                         BLOCK_JOB_DEFAULT, NULL, NULL, errp);
+    if (!s) {
         return;
     }
 
-    s = block_job_create(&stream_job_driver, bs, speed, cb, opaque, errp);
-    if (!s) {
-        return;
+    /* Make sure that the image is opened in read-write mode */
+    orig_bs_flags = bdrv_get_flags(bs);
+    if (!(orig_bs_flags & BDRV_O_RDWR)) {
+        if (bdrv_reopen(bs, orig_bs_flags | BDRV_O_RDWR, errp) != 0) {
+            block_job_unref(&s->common);
+            return;
+        }
+    }
+
+    /* Block all intermediate nodes between bs and base, because they
+     * will disappear from the chain after this operation */
+    for (iter = backing_bs(bs); iter && iter != base; iter = backing_bs(iter)) {
+        block_job_add_bdrv(&s->common, iter);
     }
 
     s->base = base;
     s->backing_file_str = g_strdup(backing_file_str);
+    s->bs_flags = orig_bs_flags;
 
     s->on_error = on_error;
-    s->common.co = qemu_coroutine_create(stream_run);
-    trace_stream_start(bs, base, s, s->common.co, opaque);
-    qemu_coroutine_enter(s->common.co, s);
+    s->common.co = qemu_coroutine_create(stream_run, s);
+    trace_stream_start(bs, base, s, s->common.co);
+    qemu_coroutine_enter(s->common.co);
 }