blkdebug: Inject errors

Add a mechanism to inject errors instead of passing requests on. With no
further patches applied, you can use it by setting inject_errno in gdb.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2010-02-19 16:24:35 +01:00
parent 6a1437273c
commit b9f66d9695
1 changed files with 81 additions and 0 deletions

View File

@ -26,10 +26,41 @@
#include "block_int.h"
#include "module.h"
#include <stdbool.h>
typedef struct BlkdebugVars {
int state;
/* If inject_errno != 0, an error is injected for requests */
int inject_errno;
/* Decides if all future requests fail (false) or only the next one and
* after the next request inject_errno is reset to 0 (true) */
bool inject_once;
/* Decides if aio_readv/writev fails right away (true) or returns an error
* return value only in the callback (false) */
bool inject_immediately;
} BlkdebugVars;
typedef struct BDRVBlkdebugState {
BlockDriverState *hd;
BlkdebugVars vars;
} BDRVBlkdebugState;
typedef struct BlkdebugAIOCB {
BlockDriverAIOCB common;
QEMUBH *bh;
int ret;
} BlkdebugAIOCB;
static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb);
static AIOPool blkdebug_aio_pool = {
.aiocb_size = sizeof(BlkdebugAIOCB),
.cancel = blkdebug_aio_cancel,
};
static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVBlkdebugState *s = bs->opaque;
@ -42,11 +73,56 @@ static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
return bdrv_file_open(&s->hd, filename, flags);
}
static void error_callback_bh(void *opaque)
{
struct BlkdebugAIOCB *acb = opaque;
qemu_bh_delete(acb->bh);
acb->common.cb(acb->common.opaque, acb->ret);
qemu_aio_release(acb);
}
static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
{
BlkdebugAIOCB *acb = (BlkdebugAIOCB*) blockacb;
qemu_aio_release(acb);
}
static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkdebugState *s = bs->opaque;
int error = s->vars.inject_errno;
struct BlkdebugAIOCB *acb;
QEMUBH *bh;
if (s->vars.inject_once) {
s->vars.inject_errno = 0;
}
if (s->vars.inject_immediately) {
return NULL;
}
acb = qemu_aio_get(&blkdebug_aio_pool, bs, cb, opaque);
acb->ret = -error;
bh = qemu_bh_new(error_callback_bh, acb);
acb->bh = bh;
qemu_bh_schedule(bh);
return (BlockDriverAIOCB*) acb;
}
static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkdebugState *s = bs->opaque;
if (s->vars.inject_errno) {
return inject_error(bs, cb, opaque);
}
BlockDriverAIOCB *acb =
bdrv_aio_readv(s->hd, sector_num, qiov, nb_sectors, cb, opaque);
return acb;
@ -57,6 +133,11 @@ static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkdebugState *s = bs->opaque;
if (s->vars.inject_errno) {
return inject_error(bs, cb, opaque);
}
BlockDriverAIOCB *acb =
bdrv_aio_writev(s->hd, sector_num, qiov, nb_sectors, cb, opaque);
return acb;