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[PULL,06/11] blockdev: Fix block_resize error reporting for op blockers

Message ID 20240309155729.1694607-7-mjt@tls.msk.ru
State New
Headers show
Series [PULL,01/11] replay: Improve error messages about configuration conflicts | expand

Commit Message

Michael Tokarev March 9, 2024, 3:57 p.m. UTC 
From: Markus Armbruster <armbru@redhat.com>

When block_resize() runs into an op blocker, it creates an error like
this:

        error_setg(errp, "Device '%s' is in use", device);

Trouble is @device can be null.  My system formats null as "(null)",
but other systems might crash.  Reproducer:

1. Create two block devices

    -> {"execute": "blockdev-add", "arguments": {"driver": "file", "node-name": "blk0", "filename": "64k.img"}}
    <- {"return": {}}
    -> {"execute": "blockdev-add", "arguments": {"driver": "file", "node-name": "blk1", "filename": "m.img"}}
    <- {"return": {}}

2. Put a blocker on one them

    -> {"execute": "blockdev-mirror", "arguments": {"job-id": "job0", "device": "blk0", "target": "blk1", "sync": "full"}}
    {"return": {}}
    -> {"execute": "job-pause", "arguments": {"id": "job0"}}
    {"return": {}}
    -> {"execute": "job-complete", "arguments": {"id": "job0"}}
    {"return": {}}

   Note: job events elided for brevity.

3. Attempt to resize

    -> {"execute": "block_resize", "arguments": {"node-name": "blk1", "size":32768}}
    <- {"error": {"class": "GenericError", "desc": "Device '(null)' is in use"}}

Broken when commit 3b1dbd11a60 made @device optional.  Fixed in commit
ed3d2ec98a3 (block: Add errp to b{lk,drv}_truncate()), except for this
one instance.

Fix it by using the error message provided by the op blocker instead,
so it fails like this:

    <- {"error": {"class": "GenericError", "desc": "Node 'blk1' is busy: block device is in use by block job: mirror"}}

Fixes: 3b1dbd11a60d (qmp: Allow block_resize to manipulate bs graph nodes.)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
---
 blockdev.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/blockdev.c b/blockdev.c
index f8bb0932f8..d8fb3399f5 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2252,8 +2252,7 @@  void coroutine_fn qmp_block_resize(const char *device, const char *node_name,
     }
 
     bdrv_graph_co_rdlock();
-    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) {
-        error_setg(errp, QERR_DEVICE_IN_USE, device);
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, errp)) {
         bdrv_graph_co_rdunlock();
         return;
     }