From c7c2ff0c7e5d2c04fc612d74caab19b41c52c2e9 Mon Sep 17 00:00:00 2001 From: Luiz Capitulino Date: Fri, 29 Aug 2014 16:07:27 -0400 Subject: [PATCH] block: extend BLOCK_IO_ERROR event with nospace indicator Management software, such as RHEV's vdsm, want to be able to allocate disk space on demand. The basic use case is to start a VM with a small disk and then the disk is enlarged when QEMU hits a ENOSPC condition. To this end, the management software has to be notified when QEMU encounters ENOSPC. The solution implemented by this commit is simple: it extends the BLOCK_IO_ERROR with a 'nospace' key, which is true when QEMU is stopped due to ENOSPC. Note that support for querying this event is already present in query-block by means of the 'io-status' key. Also, the new 'nospace' BLOCK_IO_ERROR field shares the same semantics with 'io-status', which basically means that werror= has to be set to either 'stop' or 'enospc' to enable 'nospace'. Finally, this commit also updates the 'io-status' key doc in the schema with a list of supported device models. Signed-off-by: Luiz Capitulino Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block.c | 22 ++++++++++++++-------- qapi/block-core.json | 8 +++++++- 2 files changed, 21 insertions(+), 9 deletions(-) diff --git a/block.c b/block.c index d06dd51632..460effe4fb 100644 --- a/block.c +++ b/block.c @@ -3639,6 +3639,18 @@ BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int e } } +static void send_qmp_error_event(BlockDriverState *bs, + BlockErrorAction action, + bool is_read, int error) +{ + BlockErrorAction ac; + + ac = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE; + qapi_event_send_block_io_error(bdrv_get_device_name(bs), ac, action, + bdrv_iostatus_is_enabled(bs), + error == ENOSPC, &error_abort); +} + /* This is done by device models because, while the block layer knows * about the error, it does not know whether an operation comes from * the device or the block layer (from a job, for example). @@ -3664,16 +3676,10 @@ void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action, * also ensures that the STOP/RESUME pair of events is emitted. */ qemu_system_vmstop_request_prepare(); - qapi_event_send_block_io_error(bdrv_get_device_name(bs), - is_read ? IO_OPERATION_TYPE_READ : - IO_OPERATION_TYPE_WRITE, - action, &error_abort); + send_qmp_error_event(bs, action, is_read, error); qemu_system_vmstop_request(RUN_STATE_IO_ERROR); } else { - qapi_event_send_block_io_error(bdrv_get_device_name(bs), - is_read ? IO_OPERATION_TYPE_READ : - IO_OPERATION_TYPE_WRITE, - action, &error_abort); + send_qmp_error_event(bs, action, is_read, error); } } diff --git a/qapi/block-core.json b/qapi/block-core.json index a685d02728..68945c26b2 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -336,6 +336,7 @@ # # @io-status: #optional @BlockDeviceIoStatus. Only present if the device # supports it and the VM is configured to stop on errors +# (supported device models: virtio-blk, ide, scsi-disk) # # @inserted: #optional @BlockDeviceInfo describing the device if media is # present @@ -1587,6 +1588,11 @@ # # @action: action that has been taken # +# @nospace: #optional true if I/O error was caused due to a no-space +# condition. This key is only present if query-block's +# io-status is present, please see query-block documentation +# for more information (since: 2.2) +# # Note: If action is "stop", a STOP event will eventually follow the # BLOCK_IO_ERROR event # @@ -1594,7 +1600,7 @@ ## { 'event': 'BLOCK_IO_ERROR', 'data': { 'device': 'str', 'operation': 'IoOperationType', - 'action': 'BlockErrorAction' } } + 'action': 'BlockErrorAction', '*nospace': 'bool' } } ## # @BLOCK_JOB_COMPLETED -- 2.39.2