[PATCH 05/11] qemu-io-cmds: move qemu-io commands to coroutine

[Vladimir Sementsov-Ogievskiy]

Move qemuio_command to coroutine with all qemu io commands to simplify
the code and avoid extra explicit polling loops.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 include/qemu-io.h |   9 +++-
 qemu-io-cmds.c    | 110 ++++++++++------------------------------------
 block/meson.build |   3 +-
 3 files changed, 34 insertions(+), 88 deletions(-)

diff --git a/include/qemu-io.h b/include/qemu-io.h
index 3af513004a..71cca117b9 100644
--- a/include/qemu-io.h
+++ b/include/qemu-io.h
@@ -18,6 +18,7 @@
 #ifndef QEMU_IO_H
 #define QEMU_IO_H
 
+#include "block/block.h"
 
 #define CMD_FLAG_GLOBAL ((int)0x80000000) /* don't iterate "args" */
 
@@ -45,7 +46,13 @@ typedef struct cmdinfo {
 
 extern bool qemuio_misalign;
 
-int qemuio_command(BlockBackend *blk, const char *cmd);
+int coroutine_fn qemuio_co_command(BlockBackend *blk, const char *cmd);
+
+/*
+ * Called with aio context of blk acquired. Or with qemu_get_aio_context()
+ * context acquired if no blk is NULL.
+ */
+int generated_co_wrapper qemuio_command(BlockBackend *blk, const char *cmd);
 
 void qemuio_add_command(const cmdinfo_t *ci);
 void qemuio_command_usage(const cmdinfo_t *ci);
diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 19149e014d..adc9e64c37 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -555,56 +555,16 @@ static int do_pwrite(BlockBackend *blk, char *buf, 
int64_t offset,
     return 1;
 }
 
-typedef struct {
-    BlockBackend *blk;
-    int64_t offset;
-    int64_t bytes;
-    int64_t *total;
-    int flags;
-    int ret;
-    bool done;
-} CoWriteZeroes;
-
-static void coroutine_fn co_pwrite_zeroes_entry(void *opaque)
+static int coroutine_fn
+do_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
+                    int64_t bytes, int flags, int64_t *total)
 {
-    CoWriteZeroes *data = opaque;
-
-    data->ret = blk_co_pwrite_zeroes(data->blk, data->offset, data->bytes,
-                                     data->flags);
-    data->done = true;
-    if (data->ret < 0) {
-        *data->total = data->ret;
-        return;
-    }
-
-    *data->total = data->bytes;
-}
-
-static int do_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
-                               int64_t bytes, int flags, int64_t *total)
-{
-    Coroutine *co;
-    CoWriteZeroes data = {
-        .blk    = blk,
-        .offset = offset,
-        .bytes  = bytes,
-        .total  = total,
-        .flags  = flags,
-        .done   = false,
-    };
-
-    if (bytes > INT_MAX) {
-        return -ERANGE;
-    }
-
-    co = qemu_coroutine_create(co_pwrite_zeroes_entry, &data);
-    bdrv_coroutine_enter(blk_bs(blk), co);
-    while (!data.done) {
-        aio_poll(blk_get_aio_context(blk), true);
-    }
-    if (data.ret < 0) {
-        return data.ret;
+    int ret = blk_co_pwrite_zeroes(blk, offset, bytes, flags);
+    if (ret < 0) {
+        *total = ret;
+        return ret;
     } else {
+        *total = bytes;
         return 1;
     }
 }
@@ -654,38 +614,22 @@ static int do_save_vmstate(BlockBackend *blk, char *buf, 
int64_t offset,
     return 1;
 }
 
-#define NOT_DONE 0x7fffffff
-static void aio_rw_done(void *opaque, int ret)
-{
-    *(int *)opaque = ret;
-}
-
-static int do_aio_readv(BlockBackend *blk, QEMUIOVector *qiov,
-                        int64_t offset, int *total)
+static int coroutine_fn do_co_readv(BlockBackend *blk, QEMUIOVector *qiov,
+                                    int64_t offset, int *total)
 {
-    int async_ret = NOT_DONE;
-
-    blk_aio_preadv(blk, offset, qiov, 0, aio_rw_done, &async_ret);
-    while (async_ret == NOT_DONE) {
-        main_loop_wait(false);
-    }
+    int ret = blk_co_preadv(blk, offset, qiov->size, qiov, 0);
 
     *total = qiov->size;
-    return async_ret < 0 ? async_ret : 1;
+    return ret < 0 ? ret : 1;
 }
 
-static int do_aio_writev(BlockBackend *blk, QEMUIOVector *qiov,
-                         int64_t offset, int flags, int *total)
+static int coroutine_fn do_co_writev(BlockBackend *blk, QEMUIOVector *qiov,
+                                     int64_t offset, int flags, int *total)
 {
-    int async_ret = NOT_DONE;
-
-    blk_aio_pwritev(blk, offset, qiov, flags, aio_rw_done, &async_ret);
-    while (async_ret == NOT_DONE) {
-        main_loop_wait(false);
-    }
+    int ret = blk_co_pwritev(blk, offset, qiov->size, qiov, flags);
 
     *total = qiov->size;
-    return async_ret < 0 ? async_ret : 1;
+    return ret < 0 ? ret : 1;
 }
 
 static void read_help(void)
@@ -910,7 +854,7 @@ static const cmdinfo_t readv_cmd = {
     .help       = readv_help,
 };
 
-static int readv_f(BlockBackend *blk, int argc, char **argv)
+static int coroutine_fn readv_f(BlockBackend *blk, int argc, char **argv)
 {
     struct timespec t1, t2;
     bool Cflag = false, qflag = false, vflag = false;
@@ -968,7 +912,7 @@ static int readv_f(BlockBackend *blk, int argc, char **argv)
     }
 
     clock_gettime(CLOCK_MONOTONIC, &t1);
-    ret = do_aio_readv(blk, &qiov, offset, &total);
+    ret = do_co_readv(blk, &qiov, offset, &total);
     clock_gettime(CLOCK_MONOTONIC, &t2);
 
     if (ret < 0) {
@@ -1047,7 +991,7 @@ static const cmdinfo_t write_cmd = {
     .help       = write_help,
 };
 
-static int write_f(BlockBackend *blk, int argc, char **argv)
+static int coroutine_fn write_f(BlockBackend *blk, int argc, char **argv)
 {
     struct timespec t1, t2;
     bool Cflag = false, qflag = false, bflag = false;
@@ -1235,7 +1179,7 @@ writev_help(void)
 "\n");
 }
 
-static int writev_f(BlockBackend *blk, int argc, char **argv);
+static int coroutine_fn writev_f(BlockBackend *blk, int argc, char **argv);
 
 static const cmdinfo_t writev_cmd = {
     .name       = "writev",
@@ -1248,7 +1192,7 @@ static const cmdinfo_t writev_cmd = {
     .help       = writev_help,
 };
 
-static int writev_f(BlockBackend *blk, int argc, char **argv)
+static int coroutine_fn writev_f(BlockBackend *blk, int argc, char **argv)
 {
     struct timespec t1, t2;
     bool Cflag = false, qflag = false;
@@ -1304,7 +1248,7 @@ static int writev_f(BlockBackend *blk, int argc, char 
**argv)
     }
 
     clock_gettime(CLOCK_MONOTONIC, &t1);
-    ret = do_aio_writev(blk, &qiov, offset, flags, &total);
+    ret = do_co_writev(blk, &qiov, offset, flags, &total);
     clock_gettime(CLOCK_MONOTONIC, &t2);
 
     if (ret < 0) {
@@ -2283,9 +2227,7 @@ static const cmdinfo_t resume_cmd = {
 
 static int wait_break_f(BlockBackend *blk, int argc, char **argv)
 {
-    while (!bdrv_debug_is_suspended(blk_bs(blk), argv[1])) {
-        aio_poll(blk_get_aio_context(blk), true);
-    }
+    bdrv_debug_wait_break(blk_bs(blk), argv[1]);
     return 0;
 }
 
@@ -2457,11 +2399,7 @@ static const cmdinfo_t help_cmd = {
     .oneline    = "help for one or all commands",
 };
 
-/*
- * Called with aio context of blk acquired. Or with qemu_get_aio_context()
- * context acquired if no blk is NULL.
- */
-int qemuio_command(BlockBackend *blk, const char *cmd)
+int coroutine_fn qemuio_co_command(BlockBackend *blk, const char *cmd)
 {
     char *input;
     const cmdinfo_t *ct;
diff --git a/block/meson.build b/block/meson.build
index d21990ec95..27e11aa199 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -114,7 +114,8 @@ wrapper_py = 
find_program('../scripts/block-coroutine-wrapper.py')
 block_gen_c = custom_target('block-gen.c',
                             output: 'block-gen.c',
                             input: files('../include/block/block.h',
-                                         'coroutines.h'),
+                                         'coroutines.h',
+                                         '../include/qemu-io.h'),
                             command: [wrapper_py, '@OUTPUT@', '@INPUT@'])
 block_ss.add(block_gen_c)
 
-- 
2.29.2