From 30ebb9aa9203b5051c5c4f4e2421803b94e5f2cc Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Tue, 1 Jun 2021 10:52:18 +0300 Subject: [PATCH] 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 And current error message is a bit outdated.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 Message-Id: <20210601075218.79249-7-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf --- block.c | 29 ++++++++++++++++++++------- tests/qemu-iotests/283.out | 2 +- tests/qemu-iotests/307.out | 2 +- tests/qemu-iotests/tests/qsd-jobs.out | 2 +- 4 files changed, 25 insertions(+), 10 deletions(-) diff --git a/block.c b/block.c index 3c0c3964ec..3f456892d0 100644 --- a/block.c +++ b/block.c @@ -2029,20 +2029,35 @@ static char *bdrv_child_user_desc(BdrvChild *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) { - g_autofree char *user = NULL; - g_autofree char *perm_names = NULL; + const char *child_bs_name; + 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) { return true; } - perm_names = bdrv_perm_names(b->perm & ~a->shared_perm); - user = bdrv_child_user_desc(a); - error_setg(errp, "Conflicts with use by %s as '%s', which does not " - "allow '%s' on %s", - user, a->name, perm_names, bdrv_get_node_name(b->bs)); + child_bs_name = bdrv_get_node_name(b->bs); + a_user = bdrv_child_user_desc(a); + b_user = bdrv_child_user_desc(b); + perms = bdrv_perm_names(b->perm & ~a->shared_perm); + + 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; } diff --git a/tests/qemu-iotests/283.out b/tests/qemu-iotests/283.out index c9397bfc44..c6e12b15c5 100644 --- a/tests/qemu-iotests/283.out +++ b/tests/qemu-iotests/283.out @@ -5,7 +5,7 @@ {"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": "base", "node-name": "other", "take-child-perms": ["write"]}} {"return": {}} {"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 === diff --git a/tests/qemu-iotests/307.out b/tests/qemu-iotests/307.out index 66bf2ddb74..4b0c7e155a 100644 --- a/tests/qemu-iotests/307.out +++ b/tests/qemu-iotests/307.out @@ -53,7 +53,7 @@ exports available: 1 === 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}} -{"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"}} {"return": {}} {"data": {"device": "sda", "path": "/machine/peripheral/sda"}, "event": "DEVICE_DELETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}} diff --git a/tests/qemu-iotests/tests/qsd-jobs.out b/tests/qemu-iotests/tests/qsd-jobs.out index 9f52255da8..189423354b 100644 --- a/tests/qemu-iotests/tests/qsd-jobs.out +++ b/tests/qemu-iotests/tests/qsd-jobs.out @@ -16,7 +16,7 @@ QMP_VERSION {"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": "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": {}} {"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_EXPORT_DELETED", "data": {"id": "export1"}} *** done