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blkdebug: Set request_alignment during .bdrv_refresh_limits()

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We want to eventually stick request_alignment alongside other
BlockLimits, but first, we must ensure it is populated at the
same time as all other limits, rather than being a special case
that is set only when a block is first opened.

Note that when the user does not provide "align", then we were
defaulting to bs->request_alignment - but at this stage in the
initialization, that was always 512.  We were also rejecting an
explicit "align":0 from the user; this patch now allows that,
as an explicit request for the default alignment (which may not
always be 512 in the future).

qemu-iotests 77 is particularly sensitive to the fact that we
can specify an artificial alignment override in blkdebug, and
that override must continue to work even when limits are
refreshed on an already open device.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2016-06-23 16:37:13 -06:00 committed by Kevin Wolf
parent 24ce9a2026
commit 835db3ee7b
2 changed files with 17 additions and 5 deletions
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19
block/blkdebug.c
View File

@ -37,6 +37,7 @@
typedef struct BDRVBlkdebugState {
int state;
int new_state;
int align;
QLIST_HEAD(, BlkdebugRule) rules[BLKDBG__MAX];
QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
@ -382,10 +383,10 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
}
/* Set request alignment */
align = qemu_opt_get_size(opts, "align", bs->request_alignment);
if (align > 0 && align < INT_MAX && !(align & (align - 1))) {
bs->request_alignment = align;
} else {
align = qemu_opt_get_size(opts, "align", 0);
if (align < INT_MAX && is_power_of_2(align)) {
s->align = align;
} else if (align) {
error_setg(errp, "Invalid alignment");
ret = -EINVAL;
goto fail_unref;
@ -720,6 +721,15 @@ static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *options)
bs->full_open_options = opts;
}
static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
{
BDRVBlkdebugState *s = bs->opaque;
if (s->align) {
bs->request_alignment = s->align;
}
}
static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue, Error **errp)
{
@ -738,6 +748,7 @@ static BlockDriver bdrv_blkdebug = {
.bdrv_getlength = blkdebug_getlength,
.bdrv_truncate = blkdebug_truncate,
.bdrv_refresh_filename = blkdebug_refresh_filename,
.bdrv_refresh_limits = blkdebug_refresh_limits,
.bdrv_aio_readv = blkdebug_aio_readv,
.bdrv_aio_writev = blkdebug_aio_writev,

3
qapi/block-core.json
View File

@ -1961,7 +1961,8 @@
#
# @config: #optional filename of the configuration file
#
# @align: #optional required alignment for requests in bytes
# @align: #optional required alignment for requests in bytes,
# must be power of 2, or 0 for default
#
# @inject-error: #optional array of error injection descriptions
#