| Message ID | cover.1541002357.git.berto@igalia.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Update the inherits_from pointer after stream and commit | expand |
ping > Hi all, > > when you open an image [A] with a few more images on the backing chain > you get something like this: > > [E] <- [D] <- [C] <- [B] <- [A] > > Here you can go from [A] to [E] by following the bs->backing > pointer. At the same time each one of the backing files has an > 'inherits_from' attribute pointing to their parent, so you can go from > [E] to [A] following the inherits_from pointer. > > 'inherits_from' is used on bdrv_reopen_queue_child() to decide if a > node's children must be reopened together with the parent and inherit > its options. > > If some the intermediate nodes are removed (either by block-stream or > by block-commit) you end up with something like this: > > [E] <- [A] > > In this case we would expect [E] to inherit from [A], however its > inherits_from pointer is NULL and trying to change its options by > reopening [A] with backing.option=value fails. > > This patch series fixes this. See each individual patch for more > details.
Am 31.10.2018 um 17:16 hat Alberto Garcia geschrieben: > Hi all, > > when you open an image [A] with a few more images on the backing chain > you get something like this: > > [E] <- [D] <- [C] <- [B] <- [A] > > Here you can go from [A] to [E] by following the bs->backing > pointer. At the same time each one of the backing files has an > 'inherits_from' attribute pointing to their parent, so you can go from > [E] to [A] following the inherits_from pointer. > > 'inherits_from' is used on bdrv_reopen_queue_child() to decide if a > node's children must be reopened together with the parent and inherit > its options. > > If some the intermediate nodes are removed (either by block-stream or > by block-commit) you end up with something like this: > > [E] <- [A] > > In this case we would expect [E] to inherit from [A], however its > inherits_from pointer is NULL and trying to change its options by > reopening [A] with backing.option=value fails. > > This patch series fixes this. See each individual patch for more > details. Thanks, applied to the block branch. Not a problem with the series, but I tried to run the test case without the fix, and this is what I got: -{"return": ""} +{"return": "Cannot change the option 'backing.detect-zeroes'rn"} Where does that final "rn" come from? Looks like we have a bug somewhere in the error reporting code? Kevin
On Thu 22 Nov 2018 06:52:00 PM CET, Kevin Wolf <kwolf@redhat.com> wrote: > Not a problem with the series, but I tried to run the test case without > the fix, and this is what I got: > > -{"return": ""} > +{"return": "Cannot change the option 'backing.detect-zeroes'rn"} > > Where does that final "rn" come from? Looks like we have a bug > somewhere in the error reporting code? It looks like a \r\n that hasn't been properly interpreted as CRLF. Berto
Hi all, when you open an image [A] with a few more images on the backing chain you get something like this: [E] <- [D] <- [C] <- [B] <- [A] Here you can go from [A] to [E] by following the bs->backing pointer. At the same time each one of the backing files has an 'inherits_from' attribute pointing to their parent, so you can go from [E] to [A] following the inherits_from pointer. 'inherits_from' is used on bdrv_reopen_queue_child() to decide if a node's children must be reopened together with the parent and inherit its options. If some the intermediate nodes are removed (either by block-stream or by block-commit) you end up with something like this: [E] <- [A] In this case we would expect [E] to inherit from [A], however its inherits_from pointer is NULL and trying to change its options by reopening [A] with backing.option=value fails. This patch series fixes this. See each individual patch for more details. Regards, Berto Alberto Garcia (2): block: Update BlockDriverState.inherits_from on bdrv_set_backing_hd() block: Update BlockDriverState.inherits_from on bdrv_drop_intermediate() block.c | 37 ++++++++++++ tests/qemu-iotests/161 | 137 +++++++++++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/161.out | 39 +++++++++++++ tests/qemu-iotests/group | 1 + 4 files changed, 214 insertions(+) create mode 100755 tests/qemu-iotests/161 create mode 100644 tests/qemu-iotests/161.out