[PATCH v7 00/14] Still more coroutine and various fixes in block layer

[PATCH v7 00/14] Still more coroutine and various fixes in block layer

[Emanuele Giuseppe Esposito]

This is a dump of all minor coroutine-related fixes found while looking
around and testing various things in the QEMU block layer.

Patches aim to:
- add missing coroutine_fn annotation to the functions
- simplify to avoid the typical "if in coroutine: fn()
  // else create_coroutine(fn)" already present in generated_co_wraper
  functions.
- make sure that if a BlockDriver callback is defined as coroutine_fn, then
  it is always running in a coroutine.

This serie is based on Kevin Wolf's series "block: Simplify drain".

Based-on: <20221108123738.530873-1-kwolf@redhat.com>

Emanuele
---
v6:
* use different naming for block-coroutine-wrapper annotations
* fix minor typos and patch odering

v5:
* add missing reviewed-by from Paolo
* minor indentation fixes
* use when possible _co_, but do not create new g_c_w. It will be done in
  future series
* introduce QEMU_IN_COROUTINE
* reorder patches
* rebase on kevin block branch + v2 from "block: Simplify drain"

v4:
* use v2 commit messages
* introduce coroutine_wrapper to simplify patches

v3:
* Remove patch 1, base on kevin "drain semplification serie"

v2:
* clarified commit message in patches 2/3/6 on why we add coroutine_fn

Emanuele Giuseppe Esposito (14):
  block-io: introduce coroutine_fn duplicates for
    bdrv_common_block_status_above callers
  block-copy: add coroutine_fn annotations
  nbd/server.c: add coroutine_fn annotations
  block-backend: replace bdrv_*_above with blk_*_above
  block/vmdk: add coroutine_fn annotations
  block: avoid duplicating filename string in bdrv_create
  block: distinguish between bdrv_create running in coroutine and not
  block: bdrv_create_file is a coroutine_fn
  block: rename generated_co_wrapper in co_wrapper_mixed
  block-coroutine-wrapper.py: introduce co_wrapper
  block-coroutine-wrapper.py: support functions without bs arg
  block-coroutine-wrapper.py: support also basic return types
  block: convert bdrv_create to co_wrapper
  block/dirty-bitmap: convert coroutine-only functions to co_wrapper

 docs/devel/block-coroutine-wrapper.rst |   6 +-
 block/block-gen.h                      |  11 +--
 block/coroutines.h                     |   4 +-
 include/block/block-common.h           |  20 ++--
 include/block/block-copy.h             |   5 +-
 include/block/block-global-state.h     |  11 ++-
 include/block/block-io.h               |  69 +++++++++-----
 include/block/dirty-bitmap.h           |  10 +-
 include/sysemu/block-backend-io.h      |  77 +++++++++-------
 block.c                                |  64 +++----------
 block/block-backend.c                  |  21 +++++
 block/block-copy.c                     |  21 +++--
 block/commit.c                         |   4 +-
 block/crypto.c                         |   2 +-
 block/dirty-bitmap.c                   |  88 +-----------------
 block/io.c                             |  58 +++++++++++-
 block/parallels.c                      |   2 +-
 block/qcow.c                           |   2 +-
 block/qcow2.c                          |   4 +-
 block/qed.c                            |   2 +-
 block/raw-format.c                     |   2 +-
 block/vdi.c                            |   2 +-
 block/vhdx.c                           |   2 +-
 block/vmdk.c                           |  38 ++++----
 block/vpc.c                            |   2 +-
 nbd/server.c                           |  47 +++++-----
 block/meson.build                      |   1 +
 scripts/block-coroutine-wrapper.py     | 123 +++++++++++++++++--------
 28 files changed, 375 insertions(+), 323 deletions(-)

-- 
2.31.1

[PATCH v7 01/14] block-io: introduce coroutine_fn duplicates for bdrv_common_block_status_above callers

[Emanuele Giuseppe Esposito]

bdrv_common_block_status_above() is a g_c_w, and it is being called by
many "wrapper" functions like bdrv_is_allocated(),
bdrv_is_allocated_above() and bdrv_block_status_above().

Because we want to eventually split the coroutine from non-coroutine
case in g_c_w, create duplicate wrappers that take care of directly
calling the same coroutine functions called in the g_c_w.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 include/block/block-io.h | 15 +++++++++++
 block/io.c               | 58 +++++++++++++++++++++++++++++++++++++---
 2 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/include/block/block-io.h b/include/block/block-io.h
index 92aaa7c1e9..72919254cd 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -94,14 +94,29 @@ bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 int bdrv_block_status(BlockDriverState *bs, int64_t offset,
                       int64_t bytes, int64_t *pnum, int64_t *map,
                       BlockDriverState **file);
+
+int coroutine_fn bdrv_co_block_status_above(BlockDriverState *bs,
+                                            BlockDriverState *base,
+                                            int64_t offset, int64_t bytes,
+                                            int64_t *pnum, int64_t *map,
+                                            BlockDriverState **file);
 int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
                             int64_t offset, int64_t bytes, int64_t *pnum,
                             int64_t *map, BlockDriverState **file);
+
+int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t offset,
+                                      int64_t bytes, int64_t *pnum);
 int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
                       int64_t *pnum);
+
+int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
+                                            BlockDriverState *base,
+                                            bool include_base, int64_t offset,
+                                            int64_t bytes, int64_t *pnum);
 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
                             bool include_base, int64_t offset, int64_t bytes,
                             int64_t *pnum);
+
 int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset,
                                       int64_t bytes);
 
diff --git a/block/io.c b/block/io.c
index 38e57d1f67..f4444b7777 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2533,6 +2533,17 @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
     return ret;
 }
 
+int coroutine_fn bdrv_co_block_status_above(BlockDriverState *bs,
+                                            BlockDriverState *base,
+                                            int64_t offset, int64_t bytes,
+                                            int64_t *pnum, int64_t *map,
+                                            BlockDriverState **file)
+{
+    IO_CODE();
+    return bdrv_co_common_block_status_above(bs, base, false, true, offset,
+                                             bytes, pnum, map, file, NULL);
+}
+
 int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
                             int64_t offset, int64_t bytes, int64_t *pnum,
                             int64_t *map, BlockDriverState **file)
@@ -2578,6 +2589,22 @@ int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset,
     return (pnum == bytes) && (ret & BDRV_BLOCK_ZERO);
 }
 
+int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t offset,
+                                      int64_t bytes, int64_t *pnum)
+{
+    int ret;
+    int64_t dummy;
+    IO_CODE();
+
+    ret = bdrv_co_common_block_status_above(bs, bs, true, false, offset,
+                                            bytes, pnum ? pnum : &dummy, NULL,
+                                            NULL, NULL);
+    if (ret < 0) {
+        return ret;
+    }
+    return !!(ret & BDRV_BLOCK_ALLOCATED);
+}
+
 int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
                       int64_t *pnum)
 {
@@ -2594,6 +2621,29 @@ int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
     return !!(ret & BDRV_BLOCK_ALLOCATED);
 }
 
+/* See bdrv_is_allocated_above for documentation */
+int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
+                                            BlockDriverState *base,
+                                            bool include_base, int64_t offset,
+                                            int64_t bytes, int64_t *pnum)
+{
+    int depth;
+    int ret;
+    IO_CODE();
+
+    ret = bdrv_co_common_block_status_above(top, base, include_base, false,
+                                            offset, bytes, pnum, NULL, NULL,
+                                            &depth);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (ret & BDRV_BLOCK_ALLOCATED) {
+        return depth;
+    }
+    return 0;
+}
+
 /*
  * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
  *
@@ -2617,10 +2667,12 @@ int bdrv_is_allocated_above(BlockDriverState *top,
                             int64_t bytes, int64_t *pnum)
 {
     int depth;
-    int ret = bdrv_common_block_status_above(top, base, include_base, false,
-                                             offset, bytes, pnum, NULL, NULL,
-                                             &depth);
+    int ret;
     IO_CODE();
+
+    ret = bdrv_common_block_status_above(top, base, include_base, false,
+                                         offset, bytes, pnum, NULL, NULL,
+                                         &depth);
     if (ret < 0) {
         return ret;
     }
-- 
2.31.1

[PATCH v7 02/14] block-copy: add coroutine_fn annotations

[Emanuele Giuseppe Esposito]

These functions end up calling bdrv_common_block_status_above(), a
generated_co_wrapper function.
In addition, they also happen to be always called in coroutine context,
meaning all callers are coroutine_fn.
This means that the g_c_w function will enter the qemu_in_coroutine()
case and eventually suspend (or in other words call qemu_coroutine_yield()).
Therefore we can mark such functions coroutine_fn too.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 include/block/block-copy.h |  5 +++--
 block/block-copy.c         | 21 ++++++++++++---------
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/include/block/block-copy.h b/include/block/block-copy.h
index ba0b425d78..8cea4f9b90 100644
--- a/include/block/block-copy.h
+++ b/include/block/block-copy.h
@@ -36,8 +36,9 @@ void block_copy_set_progress_meter(BlockCopyState *s, ProgressMeter *pm);
 void block_copy_state_free(BlockCopyState *s);
 
 void block_copy_reset(BlockCopyState *s, int64_t offset, int64_t bytes);
-int64_t block_copy_reset_unallocated(BlockCopyState *s,
-                                     int64_t offset, int64_t *count);
+int64_t coroutine_fn block_copy_reset_unallocated(BlockCopyState *s,
+                                                  int64_t offset,
+                                                  int64_t *count);
 
 int coroutine_fn block_copy(BlockCopyState *s, int64_t offset, int64_t bytes,
                             bool ignore_ratelimit, uint64_t timeout_ns,
diff --git a/block/block-copy.c b/block/block-copy.c
index bb947afdda..5e59d6262f 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -577,8 +577,9 @@ static coroutine_fn int block_copy_task_entry(AioTask *task)
     return ret;
 }
 
-static int block_copy_block_status(BlockCopyState *s, int64_t offset,
-                                   int64_t bytes, int64_t *pnum)
+static coroutine_fn int block_copy_block_status(BlockCopyState *s,
+                                                int64_t offset,
+                                                int64_t bytes, int64_t *pnum)
 {
     int64_t num;
     BlockDriverState *base;
@@ -590,8 +591,8 @@ static int block_copy_block_status(BlockCopyState *s, int64_t offset,
         base = NULL;
     }
 
-    ret = bdrv_block_status_above(s->source->bs, base, offset, bytes, &num,
-                                  NULL, NULL);
+    ret = bdrv_co_block_status_above(s->source->bs, base, offset, bytes, &num,
+                                     NULL, NULL);
     if (ret < 0 || num < s->cluster_size) {
         /*
          * On error or if failed to obtain large enough chunk just fallback to
@@ -613,8 +614,9 @@ static int block_copy_block_status(BlockCopyState *s, int64_t offset,
  * Check if the cluster starting at offset is allocated or not.
  * return via pnum the number of contiguous clusters sharing this allocation.
  */
-static int block_copy_is_cluster_allocated(BlockCopyState *s, int64_t offset,
-                                           int64_t *pnum)
+static int coroutine_fn block_copy_is_cluster_allocated(BlockCopyState *s,
+                                                        int64_t offset,
+                                                        int64_t *pnum)
 {
     BlockDriverState *bs = s->source->bs;
     int64_t count, total_count = 0;
@@ -624,7 +626,7 @@ static int block_copy_is_cluster_allocated(BlockCopyState *s, int64_t offset,
     assert(QEMU_IS_ALIGNED(offset, s->cluster_size));
 
     while (true) {
-        ret = bdrv_is_allocated(bs, offset, bytes, &count);
+        ret = bdrv_co_is_allocated(bs, offset, bytes, &count);
         if (ret < 0) {
             return ret;
         }
@@ -669,8 +671,9 @@ void block_copy_reset(BlockCopyState *s, int64_t offset, int64_t bytes)
  * @return 0 when the cluster at @offset was unallocated,
  *         1 otherwise, and -ret on error.
  */
-int64_t block_copy_reset_unallocated(BlockCopyState *s,
-                                     int64_t offset, int64_t *count)
+int64_t coroutine_fn block_copy_reset_unallocated(BlockCopyState *s,
+                                                  int64_t offset,
+                                                  int64_t *count)
 {
     int ret;
     int64_t clusters, bytes;
-- 
2.31.1

[PATCH v7 03/14] nbd/server.c: add coroutine_fn annotations

[Emanuele Giuseppe Esposito]

These functions end up calling bdrv_*() implemented as generated_co_wrapper
functions.
In addition, they also happen to be always called in coroutine context,
meaning all callers are coroutine_fn.
This means that the g_c_w function will enter the qemu_in_coroutine()
case and eventually suspend (or in other words call qemu_coroutine_yield()).
Therefore we can mark such functions coroutine_fn too.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 nbd/server.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/nbd/server.c b/nbd/server.c
index ada16089f3..4af5c793a7 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2141,14 +2141,15 @@ static int nbd_extent_array_add(NBDExtentArray *ea,
     return 0;
 }
 
-static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
-                                  uint64_t bytes, NBDExtentArray *ea)
+static int coroutine_fn blockstatus_to_extents(BlockDriverState *bs,
+                                               uint64_t offset, uint64_t bytes,
+                                               NBDExtentArray *ea)
 {
     while (bytes) {
         uint32_t flags;
         int64_t num;
-        int ret = bdrv_block_status_above(bs, NULL, offset, bytes, &num,
-                                          NULL, NULL);
+        int ret = bdrv_co_block_status_above(bs, NULL, offset, bytes, &num,
+                                             NULL, NULL);
 
         if (ret < 0) {
             return ret;
@@ -2168,13 +2169,14 @@ static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
     return 0;
 }
 
-static int blockalloc_to_extents(BlockDriverState *bs, uint64_t offset,
-                                 uint64_t bytes, NBDExtentArray *ea)
+static int coroutine_fn blockalloc_to_extents(BlockDriverState *bs,
+                                              uint64_t offset, uint64_t bytes,
+                                              NBDExtentArray *ea)
 {
     while (bytes) {
         int64_t num;
-        int ret = bdrv_is_allocated_above(bs, NULL, false, offset, bytes,
-                                          &num);
+        int ret = bdrv_co_is_allocated_above(bs, NULL, false, offset, bytes,
+                                             &num);
 
         if (ret < 0) {
             return ret;
@@ -2220,11 +2222,12 @@ static int nbd_co_send_extents(NBDClient *client, uint64_t handle,
 }
 
 /* Get block status from the exported device and send it to the client */
-static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
-                                    BlockDriverState *bs, uint64_t offset,
-                                    uint32_t length, bool dont_fragment,
-                                    bool last, uint32_t context_id,
-                                    Error **errp)
+static int
+coroutine_fn nbd_co_send_block_status(NBDClient *client, uint64_t handle,
+                                      BlockDriverState *bs, uint64_t offset,
+                                      uint32_t length, bool dont_fragment,
+                                      bool last, uint32_t context_id,
+                                      Error **errp)
 {
     int ret;
     unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
-- 
2.31.1

[PATCH v7 04/14] block-backend: replace bdrv_*_above with blk_*_above

[Emanuele Giuseppe Esposito]

Avoid mixing bdrv_* functions with blk_*, so create blk_* counterparts
for bdrv_block_status_above and bdrv_is_allocated_above.

Note that since blk_co_block_status_above only calls the g_c_w function
bdrv_common_block_status_above and is marked as coroutine_fn, call
directly bdrv_co_common_block_status_above() to avoid using a g_c_w.
Same applies to blk_co_is_allocated_above.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 include/sysemu/block-backend-io.h |  9 +++++++++
 block/block-backend.c             | 21 ++++++++++++++++++++
 block/commit.c                    |  4 ++--
 nbd/server.c                      | 32 +++++++++++++++----------------
 4 files changed, 48 insertions(+), 18 deletions(-)

diff --git a/include/sysemu/block-backend-io.h b/include/sysemu/block-backend-io.h
index 50f5aa2e07..ee3eb12610 100644
--- a/include/sysemu/block-backend-io.h
+++ b/include/sysemu/block-backend-io.h
@@ -92,6 +92,15 @@ int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
                                    int64_t bytes, BdrvRequestFlags read_flags,
                                    BdrvRequestFlags write_flags);
 
+int coroutine_fn blk_co_block_status_above(BlockBackend *blk,
+                                           BlockDriverState *base,
+                                           int64_t offset, int64_t bytes,
+                                           int64_t *pnum, int64_t *map,
+                                           BlockDriverState **file);
+int coroutine_fn blk_co_is_allocated_above(BlockBackend *blk,
+                                           BlockDriverState *base,
+                                           bool include_base, int64_t offset,
+                                           int64_t bytes, int64_t *pnum);
 
 /*
  * "I/O or GS" API functions. These functions can run without
diff --git a/block/block-backend.c b/block/block-backend.c
index 742efa7955..1d2d8526ef 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1424,6 +1424,27 @@ int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
     return blk_co_pwritev_part(blk, offset, bytes, qiov, 0, flags);
 }
 
+int coroutine_fn blk_co_block_status_above(BlockBackend *blk,
+                                           BlockDriverState *base,
+                                           int64_t offset, int64_t bytes,
+                                           int64_t *pnum, int64_t *map,
+                                           BlockDriverState **file)
+{
+    IO_CODE();
+    return bdrv_co_block_status_above(blk_bs(blk), base, offset, bytes, pnum,
+                                      map, file);
+}
+
+int coroutine_fn blk_co_is_allocated_above(BlockBackend *blk,
+                                           BlockDriverState *base,
+                                           bool include_base, int64_t offset,
+                                           int64_t bytes, int64_t *pnum)
+{
+    IO_CODE();
+    return bdrv_co_is_allocated_above(blk_bs(blk), base, include_base, offset,
+                                      bytes, pnum);
+}
+
 typedef struct BlkRwCo {
     BlockBackend *blk;
     int64_t offset;
diff --git a/block/commit.c b/block/commit.c
index 0029b31944..b346341767 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -155,8 +155,8 @@ static int coroutine_fn commit_run(Job *job, Error **errp)
             break;
         }
         /* Copy if allocated above the base */
-        ret = bdrv_is_allocated_above(blk_bs(s->top), s->base_overlay, true,
-                                      offset, COMMIT_BUFFER_SIZE, &n);
+        ret = blk_co_is_allocated_above(s->top, s->base_overlay, true,
+                                        offset, COMMIT_BUFFER_SIZE, &n);
         copy = (ret > 0);
         trace_commit_one_iteration(s, offset, n, ret);
         if (copy) {
diff --git a/nbd/server.c b/nbd/server.c
index 4af5c793a7..c53c39560e 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1991,7 +1991,7 @@ static int coroutine_fn nbd_co_send_structured_error(NBDClient *client,
 }
 
 /* Do a sparse read and send the structured reply to the client.
- * Returns -errno if sending fails. bdrv_block_status_above() failure is
+ * Returns -errno if sending fails. blk_co_block_status_above() failure is
  * reported to the client, at which point this function succeeds.
  */
 static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client,
@@ -2007,10 +2007,10 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client,
 
     while (progress < size) {
         int64_t pnum;
-        int status = bdrv_block_status_above(blk_bs(exp->common.blk), NULL,
-                                             offset + progress,
-                                             size - progress, &pnum, NULL,
-                                             NULL);
+        int status = blk_co_block_status_above(exp->common.blk, NULL,
+                                               offset + progress,
+                                               size - progress, &pnum, NULL,
+                                               NULL);
         bool final;
 
         if (status < 0) {
@@ -2141,15 +2141,15 @@ static int nbd_extent_array_add(NBDExtentArray *ea,
     return 0;
 }
 
-static int coroutine_fn blockstatus_to_extents(BlockDriverState *bs,
+static int coroutine_fn blockstatus_to_extents(BlockBackend *blk,
                                                uint64_t offset, uint64_t bytes,
                                                NBDExtentArray *ea)
 {
     while (bytes) {
         uint32_t flags;
         int64_t num;
-        int ret = bdrv_co_block_status_above(bs, NULL, offset, bytes, &num,
-                                             NULL, NULL);
+        int ret = blk_co_block_status_above(blk, NULL, offset, bytes, &num,
+                                            NULL, NULL);
 
         if (ret < 0) {
             return ret;
@@ -2169,14 +2169,14 @@ static int coroutine_fn blockstatus_to_extents(BlockDriverState *bs,
     return 0;
 }
 
-static int coroutine_fn blockalloc_to_extents(BlockDriverState *bs,
+static int coroutine_fn blockalloc_to_extents(BlockBackend *blk,
                                               uint64_t offset, uint64_t bytes,
                                               NBDExtentArray *ea)
 {
     while (bytes) {
         int64_t num;
-        int ret = bdrv_co_is_allocated_above(bs, NULL, false, offset, bytes,
-                                             &num);
+        int ret = blk_co_is_allocated_above(blk, NULL, false, offset, bytes,
+                                            &num);
 
         if (ret < 0) {
             return ret;
@@ -2224,7 +2224,7 @@ static int nbd_co_send_extents(NBDClient *client, uint64_t handle,
 /* Get block status from the exported device and send it to the client */
 static int
 coroutine_fn nbd_co_send_block_status(NBDClient *client, uint64_t handle,
-                                      BlockDriverState *bs, uint64_t offset,
+                                      BlockBackend *blk, uint64_t offset,
                                       uint32_t length, bool dont_fragment,
                                       bool last, uint32_t context_id,
                                       Error **errp)
@@ -2234,9 +2234,9 @@ coroutine_fn nbd_co_send_block_status(NBDClient *client, uint64_t handle,
     g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
 
     if (context_id == NBD_META_ID_BASE_ALLOCATION) {
-        ret = blockstatus_to_extents(bs, offset, length, ea);
+        ret = blockstatus_to_extents(blk, offset, length, ea);
     } else {
-        ret = blockalloc_to_extents(bs, offset, length, ea);
+        ret = blockalloc_to_extents(blk, offset, length, ea);
     }
     if (ret < 0) {
         return nbd_co_send_structured_error(
@@ -2563,7 +2563,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client,
 
             if (client->export_meta.base_allocation) {
                 ret = nbd_co_send_block_status(client, request->handle,
-                                               blk_bs(exp->common.blk),
+                                               exp->common.blk,
                                                request->from,
                                                request->len, dont_fragment,
                                                !--contexts_remaining,
@@ -2576,7 +2576,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client,
 
             if (client->export_meta.allocation_depth) {
                 ret = nbd_co_send_block_status(client, request->handle,
-                                               blk_bs(exp->common.blk),
+                                               exp->common.blk,
                                                request->from, request->len,
                                                dont_fragment,
                                                !--contexts_remaining,
-- 
2.31.1

[PATCH v7 05/14] block/vmdk: add coroutine_fn annotations

[Emanuele Giuseppe Esposito]

These functions end up calling bdrv_create() implemented as generated_co_wrapper
functions.
In addition, they also happen to be always called in coroutine context,
meaning all callers are coroutine_fn.
This means that the g_c_w function will enter the qemu_in_coroutine()
case and eventually suspend (or in other words call qemu_coroutine_yield()).
Therefore we can mark such functions coroutine_fn too.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 block/vmdk.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index 26376352b9..0c32bf2e83 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2285,10 +2285,11 @@ exit:
     return ret;
 }
 
-static int vmdk_create_extent(const char *filename, int64_t filesize,
-                              bool flat, bool compress, bool zeroed_grain,
-                              BlockBackend **pbb,
-                              QemuOpts *opts, Error **errp)
+static int coroutine_fn vmdk_create_extent(const char *filename,
+                                           int64_t filesize, bool flat,
+                                           bool compress, bool zeroed_grain,
+                                           BlockBackend **pbb,
+                                           QemuOpts *opts, Error **errp)
 {
     int ret;
     BlockBackend *blk = NULL;
@@ -2366,14 +2367,14 @@ static int filename_decompose(const char *filename, char *path, char *prefix,
  *           non-split format.
  * idx >= 1: get the n-th extent if in a split subformat
  */
-typedef BlockBackend *(*vmdk_create_extent_fn)(int64_t size,
-                                               int idx,
-                                               bool flat,
-                                               bool split,
-                                               bool compress,
-                                               bool zeroed_grain,
-                                               void *opaque,
-                                               Error **errp);
+typedef BlockBackend * coroutine_fn (*vmdk_create_extent_fn)(int64_t size,
+                                                             int idx,
+                                                             bool flat,
+                                                             bool split,
+                                                             bool compress,
+                                                             bool zeroed_grain,
+                                                             void *opaque,
+                                                             Error **errp);
 
 static void vmdk_desc_add_extent(GString *desc,
                                  const char *extent_line_fmt,
@@ -2616,7 +2617,7 @@ typedef struct {
     QemuOpts *opts;
 } VMDKCreateOptsData;
 
-static BlockBackend *vmdk_co_create_opts_cb(int64_t size, int idx,
+static BlockBackend * coroutine_fn vmdk_co_create_opts_cb(int64_t size, int idx,
                                             bool flat, bool split, bool compress,
                                             bool zeroed_grain, void *opaque,
                                             Error **errp)
@@ -2768,10 +2769,11 @@ exit:
     return ret;
 }
 
-static BlockBackend *vmdk_co_create_cb(int64_t size, int idx,
-                                       bool flat, bool split, bool compress,
-                                       bool zeroed_grain, void *opaque,
-                                       Error **errp)
+static BlockBackend * coroutine_fn vmdk_co_create_cb(int64_t size, int idx,
+                                                     bool flat, bool split,
+                                                     bool compress,
+                                                     bool zeroed_grain,
+                                                     void *opaque, Error **errp)
 {
     int ret;
     BlockDriverState *bs;
-- 
2.31.1

[PATCH v7 06/14] block: avoid duplicating filename string in bdrv_create

[Emanuele Giuseppe Esposito]

We know that the string will stay around until the function
returns, and the parameter of drv->bdrv_co_create_opts is const char*,
so it must not be modified either.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 block.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/block.c b/block.c
index 8c9f4ee37c..9d51e7b6e5 100644
--- a/block.c
+++ b/block.c
@@ -553,7 +553,7 @@ int bdrv_create(BlockDriver *drv, const char* filename,
     Coroutine *co;
     CreateCo cco = {
         .drv = drv,
-        .filename = g_strdup(filename),
+        .filename = filename,
         .opts = opts,
         .ret = NOT_DONE,
         .err = NULL,
@@ -561,8 +561,7 @@ int bdrv_create(BlockDriver *drv, const char* filename,
 
     if (!drv->bdrv_co_create_opts) {
         error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
-        ret = -ENOTSUP;
-        goto out;
+        return -ENOTSUP;
     }
 
     if (qemu_in_coroutine()) {
@@ -585,8 +584,6 @@ int bdrv_create(BlockDriver *drv, const char* filename,
         }
     }
 
-out:
-    g_free(cco.filename);
     return ret;
 }
 
-- 
2.31.1

[PATCH v7 07/14] block: distinguish between bdrv_create running in coroutine and not

[Emanuele Giuseppe Esposito]

Call two different functions depending on whether bdrv_create
is in coroutine or not, following the same pattern as
generated_co_wrapper functions.

This allows to also call the coroutine function directly,
without using CreateCo or relying in bdrv_create().

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 block.c | 69 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 34 insertions(+), 35 deletions(-)

diff --git a/block.c b/block.c
index 9d51e7b6e5..eb273dd2e3 100644
--- a/block.c
+++ b/block.c
@@ -528,63 +528,62 @@ typedef struct CreateCo {
     Error *err;
 } CreateCo;
 
-static void coroutine_fn bdrv_create_co_entry(void *opaque)
+static int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename,
+                                       QemuOpts *opts, Error **errp)
 {
-    Error *local_err = NULL;
     int ret;
+    GLOBAL_STATE_CODE();
+    ERRP_GUARD();
 
+    if (!drv->bdrv_co_create_opts) {
+        error_setg(errp, "Driver '%s' does not support image creation",
+                   drv->format_name);
+        return -ENOTSUP;
+    }
+
+    ret = drv->bdrv_co_create_opts(drv, filename, opts, errp);
+    if (ret < 0 && !*errp) {
+        error_setg_errno(errp, -ret, "Could not create image");
+    }
+
+    return ret;
+}
+
+static void coroutine_fn bdrv_create_co_entry(void *opaque)
+{
     CreateCo *cco = opaque;
-    assert(cco->drv);
     GLOBAL_STATE_CODE();
 
-    ret = cco->drv->bdrv_co_create_opts(cco->drv,
-                                        cco->filename, cco->opts, &local_err);
-    error_propagate(&cco->err, local_err);
-    cco->ret = ret;
+    cco->ret = bdrv_co_create(cco->drv, cco->filename, cco->opts, &cco->err);
+    aio_wait_kick();
 }
 
 int bdrv_create(BlockDriver *drv, const char* filename,
                 QemuOpts *opts, Error **errp)
 {
-    int ret;
-
     GLOBAL_STATE_CODE();
 
-    Coroutine *co;
-    CreateCo cco = {
-        .drv = drv,
-        .filename = filename,
-        .opts = opts,
-        .ret = NOT_DONE,
-        .err = NULL,
-    };
-
-    if (!drv->bdrv_co_create_opts) {
-        error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
-        return -ENOTSUP;
-    }
-
     if (qemu_in_coroutine()) {
         /* Fast-path if already in coroutine context */
-        bdrv_create_co_entry(&cco);
+        return bdrv_co_create(drv, filename, opts, errp);
     } else {
+        Coroutine *co;
+        CreateCo cco = {
+            .drv = drv,
+            .filename = filename,
+            .opts = opts,
+            .ret = NOT_DONE,
+            .err = NULL,
+        };
+
         co = qemu_coroutine_create(bdrv_create_co_entry, &cco);
         qemu_coroutine_enter(co);
         while (cco.ret == NOT_DONE) {
             aio_poll(qemu_get_aio_context(), true);
         }
+        error_propagate(errp, cco.err);
+        return cco.ret;
     }
-
-    ret = cco.ret;
-    if (ret < 0) {
-        if (cco.err) {
-            error_propagate(errp, cco.err);
-        } else {
-            error_setg_errno(errp, -ret, "Could not create image");
-        }
-    }
-
-    return ret;
 }
 
 /**
-- 
2.31.1

[PATCH v7 08/14] block: bdrv_create_file is a coroutine_fn

[Emanuele Giuseppe Esposito]

It is always called in coroutine_fn callbacks, therefore
it can directly call bdrv_co_create().

Rename it to bdrv_co_create_file too.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 include/block/block-global-state.h | 3 ++-
 block.c                            | 5 +++--
 block/crypto.c                     | 2 +-
 block/parallels.c                  | 2 +-
 block/qcow.c                       | 2 +-
 block/qcow2.c                      | 4 ++--
 block/qed.c                        | 2 +-
 block/raw-format.c                 | 2 +-
 block/vdi.c                        | 2 +-
 block/vhdx.c                       | 2 +-
 block/vmdk.c                       | 2 +-
 block/vpc.c                        | 2 +-
 12 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h
index 00e0cf8aea..387a7cbb2e 100644
--- a/include/block/block-global-state.h
+++ b/include/block/block-global-state.h
@@ -57,7 +57,8 @@ BlockDriver *bdrv_find_protocol(const char *filename,
 BlockDriver *bdrv_find_format(const char *format_name);
 int bdrv_create(BlockDriver *drv, const char* filename,
                 QemuOpts *opts, Error **errp);
-int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
+int coroutine_fn bdrv_co_create_file(const char *filename, QemuOpts *opts,
+                                     Error **errp);
 
 BlockDriverState *bdrv_new(void);
 int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
diff --git a/block.c b/block.c
index eb273dd2e3..20a5d7e8cf 100644
--- a/block.c
+++ b/block.c
@@ -721,7 +721,8 @@ out:
     return ret;
 }
 
-int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
+int coroutine_fn bdrv_co_create_file(const char *filename, QemuOpts *opts,
+                                     Error **errp)
 {
     QemuOpts *protocol_opts;
     BlockDriver *drv;
@@ -762,7 +763,7 @@ int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
         goto out;
     }
 
-    ret = bdrv_create(drv, filename, protocol_opts, errp);
+    ret = bdrv_co_create(drv, filename, protocol_opts, errp);
 out:
     qemu_opts_del(protocol_opts);
     qobject_unref(qdict);
diff --git a/block/crypto.c b/block/crypto.c
index 2fb8add458..bbeb9f437c 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -703,7 +703,7 @@ static int coroutine_fn block_crypto_co_create_opts_luks(BlockDriver *drv,
     }
 
     /* Create protocol layer */
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto fail;
     }
diff --git a/block/parallels.c b/block/parallels.c
index fa08c1104b..bbea2f2221 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -646,7 +646,7 @@ static int coroutine_fn parallels_co_create_opts(BlockDriver *drv,
     }
 
     /* Create and open the file (protocol layer) */
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto done;
     }
diff --git a/block/qcow.c b/block/qcow.c
index daa38839ab..18e17a5b12 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -973,7 +973,7 @@ static int coroutine_fn qcow_co_create_opts(BlockDriver *drv,
     }
 
     /* Create and open the file (protocol layer) */
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto fail;
     }
diff --git a/block/qcow2.c b/block/qcow2.c
index 4d6666d3ff..7cc49a3a6c 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3871,7 +3871,7 @@ static int coroutine_fn qcow2_co_create_opts(BlockDriver *drv,
     }
 
     /* Create and open the file (protocol layer) */
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto finish;
     }
@@ -3886,7 +3886,7 @@ static int coroutine_fn qcow2_co_create_opts(BlockDriver *drv,
     /* Create and open an external data file (protocol layer) */
     val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE);
     if (val) {
-        ret = bdrv_create_file(val, opts, errp);
+        ret = bdrv_co_create_file(val, opts, errp);
         if (ret < 0) {
             goto finish;
         }
diff --git a/block/qed.c b/block/qed.c
index c2691a85b1..9d54c8eec5 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -778,7 +778,7 @@ static int coroutine_fn bdrv_qed_co_create_opts(BlockDriver *drv,
     }
 
     /* Create and open the file (protocol layer) */
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto fail;
     }
diff --git a/block/raw-format.c b/block/raw-format.c
index a68014ef0b..28905b09ee 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -433,7 +433,7 @@ static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
                                            QemuOpts *opts,
                                            Error **errp)
 {
-    return bdrv_create_file(filename, opts, errp);
+    return bdrv_co_create_file(filename, opts, errp);
 }
 
 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
diff --git a/block/vdi.c b/block/vdi.c
index c0c111c4b9..479bcfe820 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -934,7 +934,7 @@ static int coroutine_fn vdi_co_create_opts(BlockDriver *drv,
     qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vdi_create_opts, true);
 
     /* Create and open the file (protocol layer) */
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto done;
     }
diff --git a/block/vhdx.c b/block/vhdx.c
index bad9ca691b..4c929800fe 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -2084,7 +2084,7 @@ static int coroutine_fn vhdx_co_create_opts(BlockDriver *drv,
     }
 
     /* Create and open the file (protocol layer) */
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto fail;
     }
diff --git a/block/vmdk.c b/block/vmdk.c
index 0c32bf2e83..afd3471915 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2294,7 +2294,7 @@ static int coroutine_fn vmdk_create_extent(const char *filename,
     int ret;
     BlockBackend *blk = NULL;
 
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto exit;
     }
diff --git a/block/vpc.c b/block/vpc.c
index 95841f259a..6ee95dcb96 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -1111,7 +1111,7 @@ static int coroutine_fn vpc_co_create_opts(BlockDriver *drv,
     }
 
     /* Create and open the file (protocol layer) */
-    ret = bdrv_create_file(filename, opts, errp);
+    ret = bdrv_co_create_file(filename, opts, errp);
     if (ret < 0) {
         goto fail;
     }
-- 
2.31.1

[PATCH v7 09/14] block: rename generated_co_wrapper in co_wrapper_mixed

[Emanuele Giuseppe Esposito]

In preparation to the incoming new function specifiers,
rename g_c_w with a more meaningful name and document it.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 docs/devel/block-coroutine-wrapper.rst |  6 +--
 block/coroutines.h                     |  4 +-
 include/block/block-common.h           | 11 +++--
 include/block/block-io.h               | 44 ++++++++---------
 include/sysemu/block-backend-io.h      | 68 +++++++++++++-------------
 scripts/block-coroutine-wrapper.py     |  6 +--
 6 files changed, 71 insertions(+), 68 deletions(-)

diff --git a/docs/devel/block-coroutine-wrapper.rst b/docs/devel/block-coroutine-wrapper.rst
index 412851986b..64acc8d65d 100644
--- a/docs/devel/block-coroutine-wrapper.rst
+++ b/docs/devel/block-coroutine-wrapper.rst
@@ -26,12 +26,12 @@ called ``bdrv_foo(<same args>)``. In this case the script can help. To
 trigger the generation:
 
 1. You need ``bdrv_foo`` declaration somewhere (for example, in
-   ``block/coroutines.h``) with the ``generated_co_wrapper`` mark,
+   ``block/coroutines.h``) with the ``co_wrapper_mixed`` mark,
    like this:
 
 .. code-block:: c
 
-    int generated_co_wrapper bdrv_foo(<some args>);
+    int co_wrapper_mixed bdrv_foo(<some args>);
 
 2. You need to feed this declaration to block-coroutine-wrapper script.
    For this, add the .h (or .c) file with the declaration to the
@@ -46,7 +46,7 @@ Links
 
 1. The script location is ``scripts/block-coroutine-wrapper.py``.
 
-2. Generic place for private ``generated_co_wrapper`` declarations is
+2. Generic place for private ``co_wrapper_mixed`` declarations is
    ``block/coroutines.h``, for public declarations:
    ``include/block/block.h``
 
diff --git a/block/coroutines.h b/block/coroutines.h
index 3a2bad564f..17da4db963 100644
--- a/block/coroutines.h
+++ b/block/coroutines.h
@@ -71,7 +71,7 @@ nbd_co_do_establish_connection(BlockDriverState *bs, bool blocking,
  * the "I/O or GS" API.
  */
 
-int generated_co_wrapper
+int co_wrapper_mixed
 bdrv_common_block_status_above(BlockDriverState *bs,
                                BlockDriverState *base,
                                bool include_base,
@@ -82,7 +82,7 @@ bdrv_common_block_status_above(BlockDriverState *bs,
                                int64_t *map,
                                BlockDriverState **file,
                                int *depth);
-int generated_co_wrapper
+int co_wrapper_mixed
 nbd_do_establish_connection(BlockDriverState *bs, bool blocking, Error **errp);
 
 #endif /* BLOCK_COROUTINES_H */
diff --git a/include/block/block-common.h b/include/block/block-common.h
index 297704c1e9..ec2309055b 100644
--- a/include/block/block-common.h
+++ b/include/block/block-common.h
@@ -35,14 +35,17 @@
 #include "qemu/transactions.h"
 
 /*
- * generated_co_wrapper
+ * co_wrapper{*}: Function specifiers used by block-coroutine-wrapper.py
  *
- * Function specifier, which does nothing but mark functions to be
+ * Function specifiers, which do nothing but mark functions to be
  * generated by scripts/block-coroutine-wrapper.py
  *
- * Read more in docs/devel/block-coroutine-wrapper.rst
+ * Usage: read docs/devel/block-coroutine-wrapper.rst
+ *
+ * co_wrapper_mixed functions can be called by both coroutine and
+ * non-coroutine context.
  */
-#define generated_co_wrapper
+#define co_wrapper_mixed
 
 /* block.c */
 typedef struct BlockDriver BlockDriver;
diff --git a/include/block/block-io.h b/include/block/block-io.h
index 72919254cd..72cf45975b 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -39,19 +39,19 @@
  * to catch when they are accidentally called by the wrong API.
  */
 
-int generated_co_wrapper bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
-                                            int64_t bytes,
-                                            BdrvRequestFlags flags);
+int co_wrapper_mixed bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
+                                        int64_t bytes,
+                                        BdrvRequestFlags flags);
 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
-int generated_co_wrapper bdrv_pread(BdrvChild *child, int64_t offset,
-                                    int64_t bytes, void *buf,
-                                    BdrvRequestFlags flags);
-int generated_co_wrapper bdrv_pwrite(BdrvChild *child, int64_t offset,
-                                     int64_t bytes, const void *buf,
-                                     BdrvRequestFlags flags);
-int generated_co_wrapper bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
-                                          int64_t bytes, const void *buf,
-                                          BdrvRequestFlags flags);
+int co_wrapper_mixed bdrv_pread(BdrvChild *child, int64_t offset,
+                                int64_t bytes, void *buf,
+                                BdrvRequestFlags flags);
+int co_wrapper_mixed bdrv_pwrite(BdrvChild *child, int64_t offset,
+                                 int64_t bytes, const void *buf,
+                                 BdrvRequestFlags flags);
+int co_wrapper_mixed bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
+                                      int64_t bytes, const void *buf,
+                                      BdrvRequestFlags flags);
 int coroutine_fn bdrv_co_pwrite_sync(BdrvChild *child, int64_t offset,
                                      int64_t bytes, const void *buf,
                                      BdrvRequestFlags flags);
@@ -281,22 +281,22 @@ int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset,
 
 void bdrv_drain(BlockDriverState *bs);
 
-int generated_co_wrapper
+int co_wrapper_mixed
 bdrv_truncate(BdrvChild *child, int64_t offset, bool exact,
               PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
 
-int generated_co_wrapper bdrv_check(BlockDriverState *bs, BdrvCheckResult *res,
-                                    BdrvCheckMode fix);
+int co_wrapper_mixed bdrv_check(BlockDriverState *bs, BdrvCheckResult *res,
+                                BdrvCheckMode fix);
 
 /* Invalidate any cached metadata used by image formats */
-int generated_co_wrapper bdrv_invalidate_cache(BlockDriverState *bs,
-                                               Error **errp);
-int generated_co_wrapper bdrv_flush(BlockDriverState *bs);
-int generated_co_wrapper bdrv_pdiscard(BdrvChild *child, int64_t offset,
-                                       int64_t bytes);
-int generated_co_wrapper
+int co_wrapper_mixed bdrv_invalidate_cache(BlockDriverState *bs,
+                                           Error **errp);
+int co_wrapper_mixed bdrv_flush(BlockDriverState *bs);
+int co_wrapper_mixed bdrv_pdiscard(BdrvChild *child, int64_t offset,
+                                   int64_t bytes);
+int co_wrapper_mixed
 bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
-int generated_co_wrapper
+int co_wrapper_mixed
 bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 
 /**
diff --git a/include/sysemu/block-backend-io.h b/include/sysemu/block-backend-io.h
index ee3eb12610..7ec6d978d4 100644
--- a/include/sysemu/block-backend-io.h
+++ b/include/sysemu/block-backend-io.h
@@ -110,77 +110,77 @@ int coroutine_fn blk_co_is_allocated_above(BlockBackend *blk,
  * the "I/O or GS" API.
  */
 
-int generated_co_wrapper blk_pread(BlockBackend *blk, int64_t offset,
-                                   int64_t bytes, void *buf,
-                                   BdrvRequestFlags flags);
+int co_wrapper_mixed blk_pread(BlockBackend *blk, int64_t offset,
+                               int64_t bytes, void *buf,
+                               BdrvRequestFlags flags);
 int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset, int64_t bytes,
                               void *buf, BdrvRequestFlags flags);
 
-int generated_co_wrapper blk_preadv(BlockBackend *blk, int64_t offset,
-                                    int64_t bytes, QEMUIOVector *qiov,
-                                    BdrvRequestFlags flags);
+int co_wrapper_mixed blk_preadv(BlockBackend *blk, int64_t offset,
+                                int64_t bytes, QEMUIOVector *qiov,
+                                BdrvRequestFlags flags);
 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
                                int64_t bytes, QEMUIOVector *qiov,
                                BdrvRequestFlags flags);
 
-int generated_co_wrapper blk_preadv_part(BlockBackend *blk, int64_t offset,
-                                         int64_t bytes, QEMUIOVector *qiov,
-                                         size_t qiov_offset,
-                                         BdrvRequestFlags flags);
+int co_wrapper_mixed blk_preadv_part(BlockBackend *blk, int64_t offset,
+                                     int64_t bytes, QEMUIOVector *qiov,
+                                     size_t qiov_offset,
+                                     BdrvRequestFlags flags);
 int coroutine_fn blk_co_preadv_part(BlockBackend *blk, int64_t offset,
                                     int64_t bytes, QEMUIOVector *qiov,
                                     size_t qiov_offset, BdrvRequestFlags flags);
 
-int generated_co_wrapper blk_pwrite(BlockBackend *blk, int64_t offset,
-                                    int64_t bytes, const void *buf,
-                                    BdrvRequestFlags flags);
+int co_wrapper_mixed blk_pwrite(BlockBackend *blk, int64_t offset,
+                                int64_t bytes, const void *buf,
+                                BdrvRequestFlags flags);
 int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset, int64_t bytes,
                                const void *buf, BdrvRequestFlags flags);
 
-int generated_co_wrapper blk_pwritev(BlockBackend *blk, int64_t offset,
-                                     int64_t bytes, QEMUIOVector *qiov,
-                                     BdrvRequestFlags flags);
+int co_wrapper_mixed blk_pwritev(BlockBackend *blk, int64_t offset,
+                                 int64_t bytes, QEMUIOVector *qiov,
+                                 BdrvRequestFlags flags);
 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
                                 int64_t bytes, QEMUIOVector *qiov,
                                 BdrvRequestFlags flags);
 
-int generated_co_wrapper blk_pwritev_part(BlockBackend *blk, int64_t offset,
-                                          int64_t bytes, QEMUIOVector *qiov,
-                                          size_t qiov_offset,
-                                          BdrvRequestFlags flags);
+int co_wrapper_mixed blk_pwritev_part(BlockBackend *blk, int64_t offset,
+                                      int64_t bytes, QEMUIOVector *qiov,
+                                      size_t qiov_offset,
+                                      BdrvRequestFlags flags);
 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
                                      int64_t bytes,
                                      QEMUIOVector *qiov, size_t qiov_offset,
                                      BdrvRequestFlags flags);
 
-int generated_co_wrapper blk_pwrite_compressed(BlockBackend *blk,
-                                               int64_t offset, int64_t bytes,
-                                               const void *buf);
+int co_wrapper_mixed blk_pwrite_compressed(BlockBackend *blk,
+                                           int64_t offset, int64_t bytes,
+                                           const void *buf);
 int coroutine_fn blk_co_pwrite_compressed(BlockBackend *blk, int64_t offset,
                                           int64_t bytes, const void *buf);
 
-int generated_co_wrapper blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
-                                           int64_t bytes,
-                                           BdrvRequestFlags flags);
+int co_wrapper_mixed blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
+                                       int64_t bytes,
+                                       BdrvRequestFlags flags);
 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
                                       int64_t bytes, BdrvRequestFlags flags);
 
-int generated_co_wrapper blk_pdiscard(BlockBackend *blk, int64_t offset,
-                                      int64_t bytes);
+int co_wrapper_mixed blk_pdiscard(BlockBackend *blk, int64_t offset,
+                                  int64_t bytes);
 int coroutine_fn blk_co_pdiscard(BlockBackend *blk, int64_t offset,
                                  int64_t bytes);
 
-int generated_co_wrapper blk_flush(BlockBackend *blk);
+int co_wrapper_mixed blk_flush(BlockBackend *blk);
 int coroutine_fn blk_co_flush(BlockBackend *blk);
 
-int generated_co_wrapper blk_ioctl(BlockBackend *blk, unsigned long int req,
-                                   void *buf);
+int co_wrapper_mixed blk_ioctl(BlockBackend *blk, unsigned long int req,
+                               void *buf);
 int coroutine_fn blk_co_ioctl(BlockBackend *blk, unsigned long int req,
                               void *buf);
 
-int generated_co_wrapper blk_truncate(BlockBackend *blk, int64_t offset,
-                                      bool exact, PreallocMode prealloc,
-                                      BdrvRequestFlags flags, Error **errp);
+int co_wrapper_mixed blk_truncate(BlockBackend *blk, int64_t offset,
+                                  bool exact, PreallocMode prealloc,
+                                  BdrvRequestFlags flags, Error **errp);
 int coroutine_fn blk_co_truncate(BlockBackend *blk, int64_t offset, bool exact,
                                  PreallocMode prealloc, BdrvRequestFlags flags,
                                  Error **errp);
diff --git a/scripts/block-coroutine-wrapper.py b/scripts/block-coroutine-wrapper.py
index 08be813407..56e6425356 100644
--- a/scripts/block-coroutine-wrapper.py
+++ b/scripts/block-coroutine-wrapper.py
@@ -2,7 +2,7 @@
 """Generate coroutine wrappers for block subsystem.
 
 The program parses one or several concatenated c files from stdin,
-searches for functions with the 'generated_co_wrapper' specifier
+searches for functions with the 'co_wrapper_mixed' specifier
 and generates corresponding wrappers on stdout.
 
 Usage: block-coroutine-wrapper.py generated-file.c FILE.[ch]...
@@ -74,8 +74,8 @@ def gen_block(self, format: str) -> str:
         return '\n'.join(format.format_map(arg.__dict__) for arg in self.args)
 
 
-# Match wrappers declared with a generated_co_wrapper mark
-func_decl_re = re.compile(r'^int\s*generated_co_wrapper\s*'
+# Match wrappers declared with a co_wrapper_mixed mark
+func_decl_re = re.compile(r'^int\s*co_wrapper_mixed\s*'
                           r'(?P<wrapper_name>[a-z][a-z0-9_]*)'
                           r'\((?P<args>[^)]*)\);$', re.MULTILINE)
 
-- 
2.31.1

[PATCH v7 10/14] block-coroutine-wrapper.py: introduce co_wrapper

[Emanuele Giuseppe Esposito]

This new annotation starts just a function wrapper that creates
a new coroutine. It assumes the caller is not a coroutine.
It will be the default annotation to be used in the future.

This is much better as c_w_mixed, because it is clear if the caller
is a coroutine or not, and provides the advantage of automating
the code creation. In the future all c_w_mixed functions will be
substituted by co_wrapper.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 docs/devel/block-coroutine-wrapper.rst |   6 +-
 include/block/block-common.h           |   8 +-
 scripts/block-coroutine-wrapper.py     | 110 +++++++++++++++++--------
 3 files changed, 86 insertions(+), 38 deletions(-)

diff --git a/docs/devel/block-coroutine-wrapper.rst b/docs/devel/block-coroutine-wrapper.rst
index 64acc8d65d..6dd2cdcab3 100644
--- a/docs/devel/block-coroutine-wrapper.rst
+++ b/docs/devel/block-coroutine-wrapper.rst
@@ -26,12 +26,12 @@ called ``bdrv_foo(<same args>)``. In this case the script can help. To
 trigger the generation:
 
 1. You need ``bdrv_foo`` declaration somewhere (for example, in
-   ``block/coroutines.h``) with the ``co_wrapper_mixed`` mark,
+   ``block/coroutines.h``) with the ``co_wrapper`` mark,
    like this:
 
 .. code-block:: c
 
-    int co_wrapper_mixed bdrv_foo(<some args>);
+    int co_wrapper bdrv_foo(<some args>);
 
 2. You need to feed this declaration to block-coroutine-wrapper script.
    For this, add the .h (or .c) file with the declaration to the
@@ -46,7 +46,7 @@ Links
 
 1. The script location is ``scripts/block-coroutine-wrapper.py``.
 
-2. Generic place for private ``co_wrapper_mixed`` declarations is
+2. Generic place for private ``co_wrapper`` declarations is
    ``block/coroutines.h``, for public declarations:
    ``include/block/block.h``
 
diff --git a/include/block/block-common.h b/include/block/block-common.h
index ec2309055b..847e4d4626 100644
--- a/include/block/block-common.h
+++ b/include/block/block-common.h
@@ -42,9 +42,13 @@
  *
  * Usage: read docs/devel/block-coroutine-wrapper.rst
  *
- * co_wrapper_mixed functions can be called by both coroutine and
- * non-coroutine context.
+ * There are 2 kind of specifiers:
+ * - co_wrapper functions can be called by only non-coroutine context, because
+ *   they always generate a new coroutine.
+ * - co_wrapper_mixed functions can be called by both coroutine and
+ *   non-coroutine context.
  */
+#define co_wrapper
 #define co_wrapper_mixed
 
 /* block.c */
diff --git a/scripts/block-coroutine-wrapper.py b/scripts/block-coroutine-wrapper.py
index 56e6425356..2090c3bf73 100644
--- a/scripts/block-coroutine-wrapper.py
+++ b/scripts/block-coroutine-wrapper.py
@@ -2,7 +2,7 @@
 """Generate coroutine wrappers for block subsystem.
 
 The program parses one or several concatenated c files from stdin,
-searches for functions with the 'co_wrapper_mixed' specifier
+searches for functions with the 'co_wrapper' specifier
 and generates corresponding wrappers on stdout.
 
 Usage: block-coroutine-wrapper.py generated-file.c FILE.[ch]...
@@ -62,10 +62,25 @@ def __init__(self, param_decl: str) -> None:
 
 
 class FuncDecl:
-    def __init__(self, return_type: str, name: str, args: str) -> None:
+    def __init__(self, return_type: str, name: str, args: str,
+                 variant: str) -> None:
         self.return_type = return_type.strip()
         self.name = name.strip()
+        self.struct_name = snake_to_camel(self.name)
         self.args = [ParamDecl(arg.strip()) for arg in args.split(',')]
+        self.create_only_co = 'mixed' not in variant
+
+        subsystem, subname = self.name.split('_', 1)
+        self.co_name = f'{subsystem}_co_{subname}'
+
+        t = self.args[0].type
+        if t == 'BlockDriverState *':
+            bs = 'bs'
+        elif t == 'BdrvChild *':
+            bs = 'child->bs'
+        else:
+            bs = 'blk_bs(blk)'
+        self.bs = bs
 
     def gen_list(self, format: str) -> str:
         return ', '.join(format.format_map(arg.__dict__) for arg in self.args)
@@ -74,8 +89,9 @@ def gen_block(self, format: str) -> str:
         return '\n'.join(format.format_map(arg.__dict__) for arg in self.args)
 
 
-# Match wrappers declared with a co_wrapper_mixed mark
-func_decl_re = re.compile(r'^int\s*co_wrapper_mixed\s*'
+# Match wrappers declared with a co_wrapper mark
+func_decl_re = re.compile(r'^int\s*co_wrapper'
+                          r'(?P<variant>(_[a-z][a-z0-9_]*)?)\s*'
                           r'(?P<wrapper_name>[a-z][a-z0-9_]*)'
                           r'\((?P<args>[^)]*)\);$', re.MULTILINE)
 
@@ -84,7 +100,8 @@ def func_decl_iter(text: str) -> Iterator:
     for m in func_decl_re.finditer(text):
         yield FuncDecl(return_type='int',
                        name=m.group('wrapper_name'),
-                       args=m.group('args'))
+                       args=m.group('args'),
+                       variant=m.group('variant'))
 
 
 def snake_to_camel(func_name: str) -> str:
@@ -97,24 +114,67 @@ def snake_to_camel(func_name: str) -> str:
     return ''.join(words)
 
 
+def create_mixed_wrapper(func: FuncDecl) -> str:
+    """
+    Checks if we are already in coroutine
+    """
+    name = func.co_name
+    struct_name = func.struct_name
+    return f"""\
+int {func.name}({ func.gen_list('{decl}') })
+{{
+    if (qemu_in_coroutine()) {{
+        return {name}({ func.gen_list('{name}') });
+    }} else {{
+        {struct_name} s = {{
+            .poll_state.bs = {func.bs},
+            .poll_state.in_progress = true,
+
+{ func.gen_block('            .{name} = {name},') }
+        }};
+
+        s.poll_state.co = qemu_coroutine_create({name}_entry, &s);
+
+        return bdrv_poll_co(&s.poll_state);
+    }}
+}}"""
+
+
+def create_co_wrapper(func: FuncDecl) -> str:
+    """
+    Assumes we are not in coroutine, and creates one
+    """
+    name = func.co_name
+    struct_name = func.struct_name
+    return f"""\
+int {func.name}({ func.gen_list('{decl}') })
+{{
+    {struct_name} s = {{
+        .poll_state.bs = {func.bs},
+        .poll_state.in_progress = true,
+
+{ func.gen_block('        .{name} = {name},') }
+    }};
+    assert(!qemu_in_coroutine());
+
+    s.poll_state.co = qemu_coroutine_create({name}_entry, &s);
+
+    return bdrv_poll_co(&s.poll_state);
+}}"""
+
+
 def gen_wrapper(func: FuncDecl) -> str:
     assert not '_co_' in func.name
     assert func.return_type == 'int'
     assert func.args[0].type in ['BlockDriverState *', 'BdrvChild *',
                                  'BlockBackend *']
 
-    subsystem, subname = func.name.split('_', 1)
-
-    name = f'{subsystem}_co_{subname}'
+    name = func.co_name
+    struct_name = func.struct_name
 
-    t = func.args[0].type
-    if t == 'BlockDriverState *':
-        bs = 'bs'
-    elif t == 'BdrvChild *':
-        bs = 'child->bs'
-    else:
-        bs = 'blk_bs(blk)'
-    struct_name = snake_to_camel(name)
+    creation_function = create_mixed_wrapper
+    if func.create_only_co:
+        creation_function = create_co_wrapper
 
     return f"""\
 /*
@@ -136,23 +196,7 @@ def gen_wrapper(func: FuncDecl) -> str:
     aio_wait_kick();
 }}
 
-int {func.name}({ func.gen_list('{decl}') })
-{{
-    if (qemu_in_coroutine()) {{
-        return {name}({ func.gen_list('{name}') });
-    }} else {{
-        {struct_name} s = {{
-            .poll_state.bs = {bs},
-            .poll_state.in_progress = true,
-
-{ func.gen_block('            .{name} = {name},') }
-        }};
-
-        s.poll_state.co = qemu_coroutine_create({name}_entry, &s);
-
-        return bdrv_poll_co(&s.poll_state);
-    }}
-}}"""
+{creation_function(func)}"""
 
 
 def gen_wrappers(input_code: str) -> str:
-- 
2.31.1

[PATCH v7 11/14] block-coroutine-wrapper.py: support functions without bs arg

[Emanuele Giuseppe Esposito]

Right now, we take the first parameter of the function to get the
BlockDriverState to pass to bdrv_poll_co(), that internally calls
functions that figure in which aiocontext the coroutine should run.

However, it is useless to pass a bs just to get its own AioContext,
so instead pass it directly, and default to the main loop if no
BlockDriverState is passed as parameter.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 block/block-gen.h                  |  6 +++---
 scripts/block-coroutine-wrapper.py | 16 ++++++++--------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/block/block-gen.h b/block/block-gen.h
index f80cf4897d..08d977f493 100644
--- a/block/block-gen.h
+++ b/block/block-gen.h
@@ -30,7 +30,7 @@
 
 /* Base structure for argument packing structures */
 typedef struct BdrvPollCo {
-    BlockDriverState *bs;
+    AioContext *ctx;
     bool in_progress;
     int ret;
     Coroutine *co; /* Keep pointer here for debugging */
@@ -40,8 +40,8 @@ static inline int bdrv_poll_co(BdrvPollCo *s)
 {
     assert(!qemu_in_coroutine());
 
-    bdrv_coroutine_enter(s->bs, s->co);
-    BDRV_POLL_WHILE(s->bs, s->in_progress);
+    aio_co_enter(s->ctx, s->co);
+    AIO_WAIT_WHILE(s->ctx, s->in_progress);
 
     return s->ret;
 }
diff --git a/scripts/block-coroutine-wrapper.py b/scripts/block-coroutine-wrapper.py
index 2090c3bf73..f540003af1 100644
--- a/scripts/block-coroutine-wrapper.py
+++ b/scripts/block-coroutine-wrapper.py
@@ -75,12 +75,14 @@ def __init__(self, return_type: str, name: str, args: str,
 
         t = self.args[0].type
         if t == 'BlockDriverState *':
-            bs = 'bs'
+            ctx = 'bdrv_get_aio_context(bs)'
         elif t == 'BdrvChild *':
-            bs = 'child->bs'
+            ctx = 'bdrv_get_aio_context(child->bs)'
+        elif t == 'BlockBackend *':
+            ctx = 'blk_get_aio_context(blk)'
         else:
-            bs = 'blk_bs(blk)'
-        self.bs = bs
+            ctx = 'qemu_get_aio_context()'
+        self.ctx = ctx
 
     def gen_list(self, format: str) -> str:
         return ', '.join(format.format_map(arg.__dict__) for arg in self.args)
@@ -127,7 +129,7 @@ def create_mixed_wrapper(func: FuncDecl) -> str:
         return {name}({ func.gen_list('{name}') });
     }} else {{
         {struct_name} s = {{
-            .poll_state.bs = {func.bs},
+            .poll_state.ctx = {func.ctx},
             .poll_state.in_progress = true,
 
 { func.gen_block('            .{name} = {name},') }
@@ -150,7 +152,7 @@ def create_co_wrapper(func: FuncDecl) -> str:
 int {func.name}({ func.gen_list('{decl}') })
 {{
     {struct_name} s = {{
-        .poll_state.bs = {func.bs},
+        .poll_state.ctx = {func.ctx},
         .poll_state.in_progress = true,
 
 { func.gen_block('        .{name} = {name},') }
@@ -166,8 +168,6 @@ def create_co_wrapper(func: FuncDecl) -> str:
 def gen_wrapper(func: FuncDecl) -> str:
     assert not '_co_' in func.name
     assert func.return_type == 'int'
-    assert func.args[0].type in ['BlockDriverState *', 'BdrvChild *',
-                                 'BlockBackend *']
 
     name = func.co_name
     struct_name = func.struct_name
-- 
2.31.1

[PATCH v7 12/14] block-coroutine-wrapper.py: support also basic return types

[Emanuele Giuseppe Esposito]

Extend the regex to cover also return type, pointers included.
This implies that the value returned by the function cannot be
a simple "int" anymore, but the custom return type.
Therefore remove poll_state->ret and instead use a per-function
custom "ret" field.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 block/block-gen.h                  |  5 +----
 scripts/block-coroutine-wrapper.py | 19 +++++++++++--------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/block/block-gen.h b/block/block-gen.h
index 08d977f493..89b7daaa1f 100644
--- a/block/block-gen.h
+++ b/block/block-gen.h
@@ -32,18 +32,15 @@
 typedef struct BdrvPollCo {
     AioContext *ctx;
     bool in_progress;
-    int ret;
     Coroutine *co; /* Keep pointer here for debugging */
 } BdrvPollCo;
 
-static inline int bdrv_poll_co(BdrvPollCo *s)
+static inline void bdrv_poll_co(BdrvPollCo *s)
 {
     assert(!qemu_in_coroutine());
 
     aio_co_enter(s->ctx, s->co);
     AIO_WAIT_WHILE(s->ctx, s->in_progress);
-
-    return s->ret;
 }
 
 #endif /* BLOCK_BLOCK_GEN_H */
diff --git a/scripts/block-coroutine-wrapper.py b/scripts/block-coroutine-wrapper.py
index f540003af1..71a06e917a 100644
--- a/scripts/block-coroutine-wrapper.py
+++ b/scripts/block-coroutine-wrapper.py
@@ -92,7 +92,8 @@ def gen_block(self, format: str) -> str:
 
 
 # Match wrappers declared with a co_wrapper mark
-func_decl_re = re.compile(r'^int\s*co_wrapper'
+func_decl_re = re.compile(r'^(?P<return_type>[a-zA-Z][a-zA-Z0-9_]* [\*]?)'
+                          r'\s*co_wrapper'
                           r'(?P<variant>(_[a-z][a-z0-9_]*)?)\s*'
                           r'(?P<wrapper_name>[a-z][a-z0-9_]*)'
                           r'\((?P<args>[^)]*)\);$', re.MULTILINE)
@@ -100,7 +101,7 @@ def gen_block(self, format: str) -> str:
 
 def func_decl_iter(text: str) -> Iterator:
     for m in func_decl_re.finditer(text):
-        yield FuncDecl(return_type='int',
+        yield FuncDecl(return_type=m.group('return_type'),
                        name=m.group('wrapper_name'),
                        args=m.group('args'),
                        variant=m.group('variant'))
@@ -123,7 +124,7 @@ def create_mixed_wrapper(func: FuncDecl) -> str:
     name = func.co_name
     struct_name = func.struct_name
     return f"""\
-int {func.name}({ func.gen_list('{decl}') })
+{func.return_type} {func.name}({ func.gen_list('{decl}') })
 {{
     if (qemu_in_coroutine()) {{
         return {name}({ func.gen_list('{name}') });
@@ -137,7 +138,8 @@ def create_mixed_wrapper(func: FuncDecl) -> str:
 
         s.poll_state.co = qemu_coroutine_create({name}_entry, &s);
 
-        return bdrv_poll_co(&s.poll_state);
+        bdrv_poll_co(&s.poll_state);
+        return s.ret;
     }}
 }}"""
 
@@ -149,7 +151,7 @@ def create_co_wrapper(func: FuncDecl) -> str:
     name = func.co_name
     struct_name = func.struct_name
     return f"""\
-int {func.name}({ func.gen_list('{decl}') })
+{func.return_type} {func.name}({ func.gen_list('{decl}') })
 {{
     {struct_name} s = {{
         .poll_state.ctx = {func.ctx},
@@ -161,13 +163,13 @@ def create_co_wrapper(func: FuncDecl) -> str:
 
     s.poll_state.co = qemu_coroutine_create({name}_entry, &s);
 
-    return bdrv_poll_co(&s.poll_state);
+    bdrv_poll_co(&s.poll_state);
+    return s.ret;
 }}"""
 
 
 def gen_wrapper(func: FuncDecl) -> str:
     assert not '_co_' in func.name
-    assert func.return_type == 'int'
 
     name = func.co_name
     struct_name = func.struct_name
@@ -183,6 +185,7 @@ def gen_wrapper(func: FuncDecl) -> str:
 
 typedef struct {struct_name} {{
     BdrvPollCo poll_state;
+    {func.return_type} ret;
 { func.gen_block('    {decl};') }
 }} {struct_name};
 
@@ -190,7 +193,7 @@ def gen_wrapper(func: FuncDecl) -> str:
 {{
     {struct_name} *s = opaque;
 
-    s->poll_state.ret = {name}({ func.gen_list('s->{name}') });
+    s->ret = {name}({ func.gen_list('s->{name}') });
     s->poll_state.in_progress = false;
 
     aio_wait_kick();
-- 
2.31.1

[PATCH v7 13/14] block: convert bdrv_create to co_wrapper

[Emanuele Giuseppe Esposito]

This function is never called in coroutine context, therefore
instead of manually creating a new coroutine, delegate it to the
block-coroutine-wrapper script, defining it as co_wrapper.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 include/block/block-global-state.h |  8 ++++--
 block.c                            | 41 ++----------------------------
 2 files changed, 8 insertions(+), 41 deletions(-)

diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h
index 387a7cbb2e..1f8b54f2df 100644
--- a/include/block/block-global-state.h
+++ b/include/block/block-global-state.h
@@ -55,8 +55,12 @@ BlockDriver *bdrv_find_protocol(const char *filename,
                                 bool allow_protocol_prefix,
                                 Error **errp);
 BlockDriver *bdrv_find_format(const char *format_name);
-int bdrv_create(BlockDriver *drv, const char* filename,
-                QemuOpts *opts, Error **errp);
+
+int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename,
+                                QemuOpts *opts, Error **errp);
+int co_wrapper bdrv_create(BlockDriver *drv, const char *filename,
+                           QemuOpts *opts, Error **errp);
+
 int coroutine_fn bdrv_co_create_file(const char *filename, QemuOpts *opts,
                                      Error **errp);
 
diff --git a/block.c b/block.c
index 20a5d7e8cf..8683d24553 100644
--- a/block.c
+++ b/block.c
@@ -528,8 +528,8 @@ typedef struct CreateCo {
     Error *err;
 } CreateCo;
 
-static int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename,
-                                       QemuOpts *opts, Error **errp)
+int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename,
+                                QemuOpts *opts, Error **errp)
 {
     int ret;
     GLOBAL_STATE_CODE();
@@ -549,43 +549,6 @@ static int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename,
     return ret;
 }
 
-static void coroutine_fn bdrv_create_co_entry(void *opaque)
-{
-    CreateCo *cco = opaque;
-    GLOBAL_STATE_CODE();
-
-    cco->ret = bdrv_co_create(cco->drv, cco->filename, cco->opts, &cco->err);
-    aio_wait_kick();
-}
-
-int bdrv_create(BlockDriver *drv, const char* filename,
-                QemuOpts *opts, Error **errp)
-{
-    GLOBAL_STATE_CODE();
-
-    if (qemu_in_coroutine()) {
-        /* Fast-path if already in coroutine context */
-        return bdrv_co_create(drv, filename, opts, errp);
-    } else {
-        Coroutine *co;
-        CreateCo cco = {
-            .drv = drv,
-            .filename = filename,
-            .opts = opts,
-            .ret = NOT_DONE,
-            .err = NULL,
-        };
-
-        co = qemu_coroutine_create(bdrv_create_co_entry, &cco);
-        qemu_coroutine_enter(co);
-        while (cco.ret == NOT_DONE) {
-            aio_poll(qemu_get_aio_context(), true);
-        }
-        error_propagate(errp, cco.err);
-        return cco.ret;
-    }
-}
-
 /**
  * Helper function for bdrv_create_file_fallback(): Resize @blk to at
  * least the given @minimum_size.
-- 
2.31.1

[PATCH v7 14/14] block/dirty-bitmap: convert coroutine-only functions to co_wrapper

[Emanuele Giuseppe Esposito]

bdrv_can_store_new_dirty_bitmap and bdrv_remove_persistent_dirty_bitmap
check if they are running in a coroutine, directly calling the
coroutine callback if it's the case.
Except that no coroutine calls such functions, therefore that check
can be removed, and function creation can be offloaded to
c_w.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 include/block/block-common.h |  5 +-
 include/block/block-io.h     | 10 +++-
 include/block/dirty-bitmap.h | 10 +++-
 block/dirty-bitmap.c         | 88 +-----------------------------------
 block/meson.build            |  1 +
 5 files changed, 22 insertions(+), 92 deletions(-)

diff --git a/include/block/block-common.h b/include/block/block-common.h
index 847e4d4626..6cf603ab06 100644
--- a/include/block/block-common.h
+++ b/include/block/block-common.h
@@ -29,8 +29,6 @@
 #include "qemu/iov.h"
 #include "qemu/coroutine.h"
 #include "block/accounting.h"
-#include "block/dirty-bitmap.h"
-#include "block/blockjob.h"
 #include "qemu/hbitmap.h"
 #include "qemu/transactions.h"
 
@@ -51,6 +49,9 @@
 #define co_wrapper
 #define co_wrapper_mixed
 
+#include "block/dirty-bitmap.h"
+#include "block/blockjob.h"
+
 /* block.c */
 typedef struct BlockDriver BlockDriver;
 typedef struct BdrvChild BdrvChild;
diff --git a/include/block/block-io.h b/include/block/block-io.h
index 72cf45975b..52869ea08e 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -215,8 +215,14 @@ AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c);
 void bdrv_io_plug(BlockDriverState *bs);
 void bdrv_io_unplug(BlockDriverState *bs);
 
-bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
-                                     uint32_t granularity, Error **errp);
+bool coroutine_fn bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
+                                                     const char *name,
+                                                     uint32_t granularity,
+                                                     Error **errp);
+bool co_wrapper bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs,
+                                                const char *name,
+                                                uint32_t granularity,
+                                                Error **errp);
 
 /**
  *
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 6528336c4c..c3700cec76 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -34,8 +34,14 @@ int bdrv_dirty_bitmap_check(const BdrvDirtyBitmap *bitmap, uint32_t flags,
                             Error **errp);
 void bdrv_release_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs);
-int bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name,
-                                        Error **errp);
+
+int coroutine_fn bdrv_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                                        const char *name,
+                                                        Error **errp);
+int co_wrapper bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                                   const char *name,
+                                                   Error **errp);
+
 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 void bdrv_enable_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap);
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index bf3dc0512a..21cf592889 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -388,7 +388,7 @@ void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs)
  * not fail.
  * This function doesn't release corresponding BdrvDirtyBitmap.
  */
-static int coroutine_fn
+int coroutine_fn
 bdrv_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name,
                                        Error **errp)
 {
@@ -399,45 +399,6 @@ bdrv_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name,
     return 0;
 }
 
-typedef struct BdrvRemovePersistentDirtyBitmapCo {
-    BlockDriverState *bs;
-    const char *name;
-    Error **errp;
-    int ret;
-} BdrvRemovePersistentDirtyBitmapCo;
-
-static void coroutine_fn
-bdrv_co_remove_persistent_dirty_bitmap_entry(void *opaque)
-{
-    BdrvRemovePersistentDirtyBitmapCo *s = opaque;
-
-    s->ret = bdrv_co_remove_persistent_dirty_bitmap(s->bs, s->name, s->errp);
-    aio_wait_kick();
-}
-
-int bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name,
-                                        Error **errp)
-{
-    if (qemu_in_coroutine()) {
-        return bdrv_co_remove_persistent_dirty_bitmap(bs, name, errp);
-    } else {
-        Coroutine *co;
-        BdrvRemovePersistentDirtyBitmapCo s = {
-            .bs = bs,
-            .name = name,
-            .errp = errp,
-            .ret = -EINPROGRESS,
-        };
-
-        co = qemu_coroutine_create(bdrv_co_remove_persistent_dirty_bitmap_entry,
-                                   &s);
-        bdrv_coroutine_enter(bs, co);
-        BDRV_POLL_WHILE(bs, s.ret == -EINPROGRESS);
-
-        return s.ret;
-    }
-}
-
 bool
 bdrv_supports_persistent_dirty_bitmap(BlockDriverState *bs)
 {
@@ -447,7 +408,7 @@ bdrv_supports_persistent_dirty_bitmap(BlockDriverState *bs)
     return false;
 }
 
-static bool coroutine_fn
+bool coroutine_fn
 bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
                                    uint32_t granularity, Error **errp)
 {
@@ -470,51 +431,6 @@ bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
     return drv->bdrv_co_can_store_new_dirty_bitmap(bs, name, granularity, errp);
 }
 
-typedef struct BdrvCanStoreNewDirtyBitmapCo {
-    BlockDriverState *bs;
-    const char *name;
-    uint32_t granularity;
-    Error **errp;
-    bool ret;
-
-    bool in_progress;
-} BdrvCanStoreNewDirtyBitmapCo;
-
-static void coroutine_fn bdrv_co_can_store_new_dirty_bitmap_entry(void *opaque)
-{
-    BdrvCanStoreNewDirtyBitmapCo *s = opaque;
-
-    s->ret = bdrv_co_can_store_new_dirty_bitmap(s->bs, s->name, s->granularity,
-                                                s->errp);
-    s->in_progress = false;
-    aio_wait_kick();
-}
-
-bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
-                                     uint32_t granularity, Error **errp)
-{
-    IO_CODE();
-    if (qemu_in_coroutine()) {
-        return bdrv_co_can_store_new_dirty_bitmap(bs, name, granularity, errp);
-    } else {
-        Coroutine *co;
-        BdrvCanStoreNewDirtyBitmapCo s = {
-            .bs = bs,
-            .name = name,
-            .granularity = granularity,
-            .errp = errp,
-            .in_progress = true,
-        };
-
-        co = qemu_coroutine_create(bdrv_co_can_store_new_dirty_bitmap_entry,
-                                   &s);
-        bdrv_coroutine_enter(bs, co);
-        BDRV_POLL_WHILE(bs, s.in_progress);
-
-        return s.ret;
-    }
-}
-
 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 {
     bdrv_dirty_bitmaps_lock(bitmap->bs);
diff --git a/block/meson.build b/block/meson.build
index b7c68b83a3..c48a59571e 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -137,6 +137,7 @@ block_gen_c = custom_target('block-gen.c',
                             output: 'block-gen.c',
                             input: files(
                                       '../include/block/block-io.h',
+                                      '../include/block/dirty-bitmap.h',
                                       '../include/block/block-global-state.h',
                                       '../include/sysemu/block-backend-io.h',
                                       'coroutines.h'
-- 
2.31.1

Re: [PATCH v7 00/14] Still more coroutine and various fixes in block layer

[Kevin Wolf]

Am 28.11.2022 um 15:23 hat Emanuele Giuseppe Esposito geschrieben:
> This is a dump of all minor coroutine-related fixes found while looking
> around and testing various things in the QEMU block layer.
> 
> Patches aim to:
> - add missing coroutine_fn annotation to the functions
> - simplify to avoid the typical "if in coroutine: fn()
>   // else create_coroutine(fn)" already present in generated_co_wraper
>   functions.
> - make sure that if a BlockDriver callback is defined as coroutine_fn, then
>   it is always running in a coroutine.
> 
> This serie is based on Kevin Wolf's series "block: Simplify drain".
> 
> Based-on: <20221108123738.530873-1-kwolf@redhat.com>
> 
> Emanuele

Thanks, applied to block-next.

Kevin