[PATCH v2 4/9] block/io: move bdrv_rw_co_entry and friends down

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

We are going to use bdrv_co_pwritev_part and bdrv_co_preadv_part in
bdrv_rw_co_entry, so move it down.

Note: Comment formatting was changed to conform to coding style and
function order was changed. Otherwise the code is unmodified.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 361 +++++++++++++++++++++++++++--------------------------
 1 file changed, 181 insertions(+), 180 deletions(-)

diff --git a/block/io.c b/block/io.c
index 1134f8144a..061f3f2590 100644
--- a/block/io.c
+++ b/block/io.c
@@ -891,186 +891,6 @@ static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
     return 0;
 }
 
-typedef struct RwCo {
-    BdrvChild *child;
-    int64_t offset;
-    QEMUIOVector *qiov;
-    bool is_write;
-    int ret;
-    BdrvRequestFlags flags;
-} RwCo;
-
-static void coroutine_fn bdrv_rw_co_entry(void *opaque)
-{
-    RwCo *rwco = opaque;
-
-    if (!rwco->is_write) {
-        rwco->ret = bdrv_co_preadv(rwco->child, rwco->offset,
-                                   rwco->qiov->size, rwco->qiov,
-                                   rwco->flags);
-    } else {
-        rwco->ret = bdrv_co_pwritev(rwco->child, rwco->offset,
-                                    rwco->qiov->size, rwco->qiov,
-                                    rwco->flags);
-    }
-    aio_wait_kick();
-}
-
-/*
- * Process a vectored synchronous request using coroutines
- */
-static int bdrv_prwv_co(BdrvChild *child, int64_t offset,
-                        QEMUIOVector *qiov, bool is_write,
-                        BdrvRequestFlags flags)
-{
-    Coroutine *co;
-    RwCo rwco = {
-        .child = child,
-        .offset = offset,
-        .qiov = qiov,
-        .is_write = is_write,
-        .ret = NOT_DONE,
-        .flags = flags,
-    };
-
-    if (qemu_in_coroutine()) {
-        /* Fast-path if already in coroutine context */
-        bdrv_rw_co_entry(&rwco);
-    } else {
-        co = qemu_coroutine_create(bdrv_rw_co_entry, &rwco);
-        bdrv_coroutine_enter(child->bs, co);
-        BDRV_POLL_WHILE(child->bs, rwco.ret == NOT_DONE);
-    }
-    return rwco.ret;
-}
-
-int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
-                       int bytes, BdrvRequestFlags flags)
-{
-    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes);
-
-    return bdrv_prwv_co(child, offset, &qiov, true,
-                        BDRV_REQ_ZERO_WRITE | flags);
-}
-
-/*
- * Completely zero out a block device with the help of bdrv_pwrite_zeroes.
- * The operation is sped up by checking the block status and only writing
- * zeroes to the device if they currently do not return zeroes. Optional
- * flags are passed through to bdrv_pwrite_zeroes (e.g. BDRV_REQ_MAY_UNMAP,
- * BDRV_REQ_FUA).
- *
- * Returns < 0 on error, 0 on success. For error codes see bdrv_write().
- */
-int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
-{
-    int ret;
-    int64_t target_size, bytes, offset = 0;
-    BlockDriverState *bs = child->bs;
-
-    target_size = bdrv_getlength(bs);
-    if (target_size < 0) {
-        return target_size;
-    }
-
-    for (;;) {
-        bytes = MIN(target_size - offset, BDRV_REQUEST_MAX_BYTES);
-        if (bytes <= 0) {
-            return 0;
-        }
-        ret = bdrv_block_status(bs, offset, bytes, &bytes, NULL, NULL);
-        if (ret < 0) {
-            return ret;
-        }
-        if (ret & BDRV_BLOCK_ZERO) {
-            offset += bytes;
-            continue;
-        }
-        ret = bdrv_pwrite_zeroes(child, offset, bytes, flags);
-        if (ret < 0) {
-            return ret;
-        }
-        offset += bytes;
-    }
-}
-
-int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov)
-{
-    int ret;
-
-    ret = bdrv_prwv_co(child, offset, qiov, false, 0);
-    if (ret < 0) {
-        return ret;
-    }
-
-    return qiov->size;
-}
-
-/* See bdrv_pwrite() for the return codes */
-int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes)
-{
-    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
-
-    if (bytes < 0) {
-        return -EINVAL;
-    }
-
-    return bdrv_preadv(child, offset, &qiov);
-}
-
-int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov)
-{
-    int ret;
-
-    ret = bdrv_prwv_co(child, offset, qiov, true, 0);
-    if (ret < 0) {
-        return ret;
-    }
-
-    return qiov->size;
-}
-
-/* Return no. of bytes on success or < 0 on error. Important errors are:
-  -EIO         generic I/O error (may happen for all errors)
-  -ENOMEDIUM   No media inserted.
-  -EINVAL      Invalid offset or number of bytes
-  -EACCES      Trying to write a read-only device
-*/
-int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes)
-{
-    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
-
-    if (bytes < 0) {
-        return -EINVAL;
-    }
-
-    return bdrv_pwritev(child, offset, &qiov);
-}
-
-/*
- * Writes to the file and ensures that no writes are reordered across this
- * request (acts as a barrier)
- *
- * Returns 0 on success, -errno in error cases.
- */
-int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
-                     const void *buf, int count)
-{
-    int ret;
-
-    ret = bdrv_pwrite(child, offset, buf, count);
-    if (ret < 0) {
-        return ret;
-    }
-
-    ret = bdrv_flush(child->bs);
-    if (ret < 0) {
-        return ret;
-    }
-
-    return 0;
-}
-
 typedef struct CoroutineIOCompletion {
     Coroutine *coroutine;
     int ret;
@@ -2185,6 +2005,187 @@ int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
                            BDRV_REQ_ZERO_WRITE | flags);
 }
 
+typedef struct RwCo {
+    BdrvChild *child;
+    int64_t offset;
+    QEMUIOVector *qiov;
+    bool is_write;
+    int ret;
+    BdrvRequestFlags flags;
+} RwCo;
+
+static void coroutine_fn bdrv_rw_co_entry(void *opaque)
+{
+    RwCo *rwco = opaque;
+
+    if (!rwco->is_write) {
+        rwco->ret = bdrv_co_preadv(rwco->child, rwco->offset,
+                                   rwco->qiov->size, rwco->qiov,
+                                   rwco->flags);
+    } else {
+        rwco->ret = bdrv_co_pwritev(rwco->child, rwco->offset,
+                                    rwco->qiov->size, rwco->qiov,
+                                    rwco->flags);
+    }
+    aio_wait_kick();
+}
+
+/*
+ * Process a vectored synchronous request using coroutines
+ */
+static int bdrv_prwv_co(BdrvChild *child, int64_t offset,
+                        QEMUIOVector *qiov, bool is_write,
+                        BdrvRequestFlags flags)
+{
+    Coroutine *co;
+    RwCo rwco = {
+        .child = child,
+        .offset = offset,
+        .qiov = qiov,
+        .is_write = is_write,
+        .ret = NOT_DONE,
+        .flags = flags,
+    };
+
+    if (qemu_in_coroutine()) {
+        /* Fast-path if already in coroutine context */
+        bdrv_rw_co_entry(&rwco);
+    } else {
+        co = qemu_coroutine_create(bdrv_rw_co_entry, &rwco);
+        bdrv_coroutine_enter(child->bs, co);
+        BDRV_POLL_WHILE(child->bs, rwco.ret == NOT_DONE);
+    }
+    return rwco.ret;
+}
+
+int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
+                       int bytes, BdrvRequestFlags flags)
+{
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes);
+
+    return bdrv_prwv_co(child, offset, &qiov, true,
+                        BDRV_REQ_ZERO_WRITE | flags);
+}
+
+/* See bdrv_pwrite() for the return codes */
+int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes)
+{
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
+
+    if (bytes < 0) {
+        return -EINVAL;
+    }
+
+    return bdrv_preadv(child, offset, &qiov);
+}
+
+int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov)
+{
+    int ret;
+
+    ret = bdrv_prwv_co(child, offset, qiov, true, 0);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return qiov->size;
+}
+
+/*
+ * Return no. of bytes on success or < 0 on error. Important errors are:
+ * -EIO         generic I/O error (may happen for all errors)
+ * -ENOMEDIUM   No media inserted.
+ * -EINVAL      Invalid offset or number of bytes
+ * -EACCES      Trying to write a read-only device
+ */
+int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes)
+{
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
+
+    if (bytes < 0) {
+        return -EINVAL;
+    }
+
+    return bdrv_pwritev(child, offset, &qiov);
+}
+
+/*
+ * Writes to the file and ensures that no writes are reordered across this
+ * request (acts as a barrier)
+ *
+ * Returns 0 on success, -errno in error cases.
+ */
+int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
+                     const void *buf, int count)
+{
+    int ret;
+
+    ret = bdrv_pwrite(child, offset, buf, count);
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = bdrv_flush(child->bs);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return 0;
+}
+
+/*
+ * Completely zero out a block device with the help of bdrv_pwrite_zeroes.
+ * The operation is sped up by checking the block status and only writing
+ * zeroes to the device if they currently do not return zeroes. Optional
+ * flags are passed through to bdrv_pwrite_zeroes (e.g. BDRV_REQ_MAY_UNMAP,
+ * BDRV_REQ_FUA).
+ *
+ * Returns < 0 on error, 0 on success. For error codes see bdrv_write().
+ */
+int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
+{
+    int ret;
+    int64_t target_size, bytes, offset = 0;
+    BlockDriverState *bs = child->bs;
+
+    target_size = bdrv_getlength(bs);
+    if (target_size < 0) {
+        return target_size;
+    }
+
+    for (;;) {
+        bytes = MIN(target_size - offset, BDRV_REQUEST_MAX_BYTES);
+        if (bytes <= 0) {
+            return 0;
+        }
+        ret = bdrv_block_status(bs, offset, bytes, &bytes, NULL, NULL);
+        if (ret < 0) {
+            return ret;
+        }
+        if (ret & BDRV_BLOCK_ZERO) {
+            offset += bytes;
+            continue;
+        }
+        ret = bdrv_pwrite_zeroes(child, offset, bytes, flags);
+        if (ret < 0) {
+            return ret;
+        }
+        offset += bytes;
+    }
+}
+
+int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov)
+{
+    int ret;
+
+    ret = bdrv_prwv_co(child, offset, qiov, false, 0);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return qiov->size;
+}
+
 /*
  * Flush ALL BDSes regardless of if they are reachable via a BlkBackend or not.
  */
-- 
2.21.0