block: improve permission conflict error message

Now permissions are updated as follows:
 1. do graph modifications ignoring permissions
 2. do permission update

 (of course, we rollback [1] if [2] fails)

So, on stage [2] we can't say which users are "old" and which are
"new" and exist only since [1]. And current error message is a bit
outdated. Let's improve it, to make everything clean.

While being here, add also a comment and some good assertions.

iotests 283, 307, qsd-jobs outputs are updated.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210601075218.79249-7-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2021-06-01 10:52:18 +03:00 committed by Kevin Wolf
parent da261b69ae
commit 30ebb9aa92
4 changed files with 25 additions and 10 deletions

29
block.c
View File

@ -2029,20 +2029,35 @@ static char *bdrv_child_user_desc(BdrvChild *c)
return c->klass->get_parent_desc(c); return c->klass->get_parent_desc(c);
} }
/*
* Check that @a allows everything that @b needs. @a and @b must reference same
* child node.
*/
static bool bdrv_a_allow_b(BdrvChild *a, BdrvChild *b, Error **errp) static bool bdrv_a_allow_b(BdrvChild *a, BdrvChild *b, Error **errp)
{ {
g_autofree char *user = NULL; const char *child_bs_name;
g_autofree char *perm_names = NULL; g_autofree char *a_user = NULL;
g_autofree char *b_user = NULL;
g_autofree char *perms = NULL;
assert(a->bs);
assert(a->bs == b->bs);
if ((b->perm & a->shared_perm) == b->perm) { if ((b->perm & a->shared_perm) == b->perm) {
return true; return true;
} }
perm_names = bdrv_perm_names(b->perm & ~a->shared_perm); child_bs_name = bdrv_get_node_name(b->bs);
user = bdrv_child_user_desc(a); a_user = bdrv_child_user_desc(a);
error_setg(errp, "Conflicts with use by %s as '%s', which does not " b_user = bdrv_child_user_desc(b);
"allow '%s' on %s", perms = bdrv_perm_names(b->perm & ~a->shared_perm);
user, a->name, perm_names, bdrv_get_node_name(b->bs));
error_setg(errp, "Permission conflict on node '%s': permissions '%s' are "
"both required by %s (uses node '%s' as '%s' child) and "
"unshared by %s (uses node '%s' as '%s' child).",
child_bs_name, perms,
b_user, child_bs_name, b->name,
a_user, child_bs_name, a->name);
return false; return false;
} }

View File

@ -5,7 +5,7 @@
{"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": "base", "node-name": "other", "take-child-perms": ["write"]}} {"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": "base", "node-name": "other", "take-child-perms": ["write"]}}
{"return": {}} {"return": {}}
{"execute": "blockdev-backup", "arguments": {"device": "source", "sync": "full", "target": "target"}} {"execute": "blockdev-backup", "arguments": {"device": "source", "sync": "full", "target": "target"}}
{"error": {"class": "GenericError", "desc": "Cannot append backup-top filter: Conflicts with use by node 'source' as 'image', which does not allow 'write' on base"}} {"error": {"class": "GenericError", "desc": "Cannot append backup-top filter: Permission conflict on node 'base': permissions 'write' are both required by node 'other' (uses node 'base' as 'image' child) and unshared by node 'source' (uses node 'base' as 'image' child)."}}
=== backup-top should be gone after job-finalize === === backup-top should be gone after job-finalize ===

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@ -53,7 +53,7 @@ exports available: 1
=== Add a writable export === === Add a writable export ===
{"execute": "block-export-add", "arguments": {"description": "This is the writable second export", "id": "export1", "name": "export1", "node-name": "fmt", "type": "nbd", "writable": true, "writethrough": true}} {"execute": "block-export-add", "arguments": {"description": "This is the writable second export", "id": "export1", "name": "export1", "node-name": "fmt", "type": "nbd", "writable": true, "writethrough": true}}
{"error": {"class": "GenericError", "desc": "Conflicts with use by block device 'sda' as 'root', which does not allow 'write' on fmt"}} {"error": {"class": "GenericError", "desc": "Permission conflict on node 'fmt': permissions 'write' are both required by an unnamed block device (uses node 'fmt' as 'root' child) and unshared by block device 'sda' (uses node 'fmt' as 'root' child)."}}
{"execute": "device_del", "arguments": {"id": "sda"}} {"execute": "device_del", "arguments": {"id": "sda"}}
{"return": {}} {"return": {}}
{"data": {"device": "sda", "path": "/machine/peripheral/sda"}, "event": "DEVICE_DELETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} {"data": {"device": "sda", "path": "/machine/peripheral/sda"}, "event": "DEVICE_DELETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}

View File

@ -16,7 +16,7 @@ QMP_VERSION
{"return": {}} {"return": {}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}} {"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "null", "id": "job0"}} {"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "null", "id": "job0"}}
{"error": {"class": "GenericError", "desc": "Conflicts with use by stream job 'job0' as 'intermediate node', which does not allow 'write' on fmt_base"}} {"error": {"class": "GenericError", "desc": "Permission conflict on node 'fmt_base': permissions 'write' are both required by an unnamed block device (uses node 'fmt_base' as 'root' child) and unshared by stream job 'job0' (uses node 'fmt_base' as 'intermediate node' child)."}}
{"return": {}} {"return": {}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_EXPORT_DELETED", "data": {"id": "export1"}} {"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_EXPORT_DELETED", "data": {"id": "export1"}}
*** done *** done