target/arm: Don't read r4 from v8M exception stackframe twice

[qemu.git] / block / throttle.c

diff --git a/block/throttle.c b/block/throttle.c
index 5bca76300f8c728aec7c503f5f03e07ec0b964e7..636c9764aaa564df104cb9c51e5140dacaae2cec 100644 (file)
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -19,6 +19,7 @@
 
 #include "qemu/osdep.h"
 #include "block/throttle-groups.h"
+#include "qemu/option.h"
 #include "qemu/throttle-options.h"
 #include "qapi/error.h"
 
@@ -35,9 +36,12 @@ static QemuOptsList throttle_opts = {
     },
 };
 
-static int throttle_configure_tgm(BlockDriverState *bs,
-                                  ThrottleGroupMember *tgm,
-                                  QDict *options, Error **errp)
+/*
+ * If this function succeeds then the throttle group name is stored in
+ * @group and must be freed by the caller.
+ * If there's an error then @group remains unmodified.
+ */
+static int throttle_parse_options(QDict *options, char **group, Error **errp)
 {
     int ret;
     const char *group_name;
@@ -62,8 +66,7 @@ static int throttle_configure_tgm(BlockDriverState *bs,
         goto fin;
     }
 
-    /* Register membership to group with name group_name */
-    throttle_group_register_tgm(tgm, group_name, bdrv_get_aio_context(bs));
+    *group = g_strdup(group_name);
     ret = 0;
 fin:
     qemu_opts_del(opts);
@@ -74,16 +77,27 @@ static int throttle_open(BlockDriverState *bs, QDict *options,
                          int flags, Error **errp)
 {
     ThrottleGroupMember *tgm = bs->opaque;
+    char *group;
+    int ret;
 
     bs->file = bdrv_open_child(NULL, options, "file", bs,
                                &child_file, false, errp);
     if (!bs->file) {
         return -EINVAL;
     }
-    bs->supported_write_flags = bs->file->bs->supported_write_flags;
-    bs->supported_zero_flags = bs->file->bs->supported_zero_flags;
+    bs->supported_write_flags = bs->file->bs->supported_write_flags |
+                                BDRV_REQ_WRITE_UNCHANGED;
+    bs->supported_zero_flags = bs->file->bs->supported_zero_flags |
+                               BDRV_REQ_WRITE_UNCHANGED;
+
+    ret = throttle_parse_options(options, &group, errp);
+    if (ret == 0) {
+        /* Register membership to group with name group_name */
+        throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs));
+        g_free(group);
+    }
 
-    return throttle_configure_tgm(bs, tgm, options, errp);
+    return ret;
 }
 
 static void throttle_close(BlockDriverState *bs)
@@ -135,7 +149,7 @@ static int coroutine_fn throttle_co_pdiscard(BlockDriverState *bs,
     ThrottleGroupMember *tgm = bs->opaque;
     throttle_group_co_io_limits_intercept(tgm, bytes, true);
 
-    return bdrv_co_pdiscard(bs->file->bs, offset, bytes);
+    return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
 
 static int throttle_co_flush(BlockDriverState *bs)
@@ -159,35 +173,36 @@ static void throttle_attach_aio_context(BlockDriverState *bs,
 static int throttle_reopen_prepare(BDRVReopenState *reopen_state,
                                    BlockReopenQueue *queue, Error **errp)
 {
-    ThrottleGroupMember *tgm;
+    int ret;
+    char *group = NULL;
 
     assert(reopen_state != NULL);
     assert(reopen_state->bs != NULL);
 
-    reopen_state->opaque = g_new0(ThrottleGroupMember, 1);
-    tgm = reopen_state->opaque;
-
-    return throttle_configure_tgm(reopen_state->bs, tgm, reopen_state->options,
-            errp);
+    ret = throttle_parse_options(reopen_state->options, &group, errp);
+    reopen_state->opaque = group;
+    return ret;
 }
 
 static void throttle_reopen_commit(BDRVReopenState *reopen_state)
 {
-    ThrottleGroupMember *old_tgm = reopen_state->bs->opaque;
-    ThrottleGroupMember *new_tgm = reopen_state->opaque;
+    BlockDriverState *bs = reopen_state->bs;
+    ThrottleGroupMember *tgm = bs->opaque;
+    char *group = reopen_state->opaque;
 
-    throttle_group_unregister_tgm(old_tgm);
-    g_free(old_tgm);
-    reopen_state->bs->opaque = new_tgm;
+    assert(group);
+
+    if (strcmp(group, throttle_group_get_name(tgm))) {
+        throttle_group_unregister_tgm(tgm);
+        throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs));
+    }
+    g_free(reopen_state->opaque);
     reopen_state->opaque = NULL;
 }
 
 static void throttle_reopen_abort(BDRVReopenState *reopen_state)
 {
-    ThrottleGroupMember *tgm = reopen_state->opaque;
-
-    throttle_group_unregister_tgm(tgm);
-    g_free(tgm);
+    g_free(reopen_state->opaque);
     reopen_state->opaque = NULL;
 }
 
@@ -197,12 +212,26 @@ static bool throttle_recurse_is_first_non_filter(BlockDriverState *bs,
     return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate);
 }
 
+static void coroutine_fn throttle_co_drain_begin(BlockDriverState *bs)
+{
+    ThrottleGroupMember *tgm = bs->opaque;
+    if (atomic_fetch_inc(&tgm->io_limits_disabled) == 0) {
+        throttle_group_restart_tgm(tgm);
+    }
+}
+
+static void coroutine_fn throttle_co_drain_end(BlockDriverState *bs)
+{
+    ThrottleGroupMember *tgm = bs->opaque;
+    assert(tgm->io_limits_disabled);
+    atomic_dec(&tgm->io_limits_disabled);
+}
+
 static BlockDriver bdrv_throttle = {
     .format_name                        =   "throttle",
-    .protocol_name                      =   "throttle",
     .instance_size                      =   sizeof(ThrottleGroupMember),
 
-    .bdrv_file_open                     =   throttle_open,
+    .bdrv_open                          =   throttle_open,
     .bdrv_close                         =   throttle_close,
     .bdrv_co_flush                      =   throttle_co_flush,
 
@@ -224,7 +253,10 @@ static BlockDriver bdrv_throttle = {
     .bdrv_reopen_prepare                =   throttle_reopen_prepare,
     .bdrv_reopen_commit                 =   throttle_reopen_commit,
     .bdrv_reopen_abort                  =   throttle_reopen_abort,
-    .bdrv_co_get_block_status           =   bdrv_co_get_block_status_from_file,
+    .bdrv_co_block_status               =   bdrv_co_block_status_from_file,
+
+    .bdrv_co_drain_begin                =   throttle_co_drain_begin,
+    .bdrv_co_drain_end                  =   throttle_co_drain_end,
 
     .is_filter                          =   true,
 };