blkdebug: add "remove_break" command

This adds "remove_break" command which is the reverse of blkdebug
command "break": it removes all breakpoints with given tag and resumes
all the requests.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

block.c

@@ -3525,6 +3525,19 @@ int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
     return -ENOTSUP;
 }
 
+int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
+{
+    while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
+        bs = bs->file;
+    }
+
+    if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
+        return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
+    }
+
+    return -ENOTSUP;
+}
+
 int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
 {
     while (bs && bs->drv && !bs->drv->bdrv_debug_resume) {

block/blkdebug.c

@@ -605,6 +605,31 @@ static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
     return -ENOENT;
 }
 
+static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
+                                            const char *tag)
+{
+    BDRVBlkdebugState *s = bs->opaque;
+    BlkdebugSuspendedReq *r;
+    BlkdebugRule *rule, *next;
+    int i, ret = -ENOENT;
+
+    for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
+        QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
+            if (rule->action == ACTION_SUSPEND &&
+                !strcmp(rule->options.suspend.tag, tag)) {
+                remove_rule(rule);
+                ret = 0;
+            }
+        }
+    }
+    QLIST_FOREACH(r, &s->suspended_reqs, next) {
+        if (!strcmp(r->tag, tag)) {
+            qemu_coroutine_enter(r->co, NULL);
+            ret = 0;
+        }
+    }
+    return ret;
+}
 
 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 {
@@ -639,6 +664,8 @@ static BlockDriver bdrv_blkdebug = {
 
     .bdrv_debug_event           = blkdebug_debug_event,
     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
+    .bdrv_debug_remove_breakpoint
+                                = blkdebug_debug_remove_breakpoint,
     .bdrv_debug_resume          = blkdebug_debug_resume,
     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 };

include/block/block.h

@@ -519,6 +519,7 @@ void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event);
 
 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
                            const char *tag);
+int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 

include/block/block_int.h

@@ -219,6 +219,8 @@ struct BlockDriver {
     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
         const char *tag);
+    int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
+        const char *tag);
     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 

qemu-io-cmds.c

@@ -1956,6 +1956,18 @@ static int break_f(BlockDriverState *bs, int argc, char **argv)
     return 0;
 }
 
+static int remove_break_f(BlockDriverState *bs, int argc, char **argv)
+{
+    int ret;
+
+    ret = bdrv_debug_remove_breakpoint(bs, argv[1]);
+    if (ret < 0) {
+        printf("Could not remove breakpoint %s: %s\n", argv[1], strerror(-ret));
+    }
+
+    return 0;
+}
+
 static const cmdinfo_t break_cmd = {
        .name           = "break",
        .argmin         = 2,
@@ -1966,6 +1978,15 @@ static const cmdinfo_t break_cmd = {
                          "request as tag",
 };
 
+static const cmdinfo_t remove_break_cmd = {
+       .name           = "remove_break",
+       .argmin         = 1,
+       .argmax         = 1,
+       .cfunc          = remove_break_f,
+       .args           = "tag",
+       .oneline        = "remove a breakpoint by tag",
+};
+
 static int resume_f(BlockDriverState *bs, int argc, char **argv)
 {
     int ret;
@@ -2126,6 +2147,7 @@ static void __attribute((constructor)) init_qemuio_commands(void)
     qemuio_add_command(&alloc_cmd);
     qemuio_add_command(&map_cmd);
     qemuio_add_command(&break_cmd);
+    qemuio_add_command(&remove_break_cmd);
     qemuio_add_command(&resume_cmd);
     qemuio_add_command(&wait_break_cmd);
     qemuio_add_command(&abort_cmd);