block: Convert bdrv_is_inserted() to co_wrapper

bdrv_is_inserted() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

At the same time, add also blk_is_inserted as co_wrapper_mixed, since it
is called in both coroutine and non-coroutine contexts.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally c_w_mixed_bdrv_rdlock calls AIO_WAIT_WHILE and it expects to
release the AioContext lock. Once the rwlock is ultimated and placed in
every place it needs to be, we will poll using AIO_WAIT_WHILE_UNLOCKED
and remove the AioContext lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-5-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Emanuele Giuseppe Esposito 2023-01-13 21:42:02 +01:00 committed by Kevin Wolf
parent 09d9fc97f8
commit 1e97be9156
8 changed files with 32 additions and 20 deletions

View File

@ -6782,7 +6782,7 @@ out:
/**
* Return TRUE if the media is present
*/
bool bdrv_is_inserted(BlockDriverState *bs)
bool coroutine_fn bdrv_co_is_inserted(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
BdrvChild *child;
@ -6791,11 +6791,11 @@ bool bdrv_is_inserted(BlockDriverState *bs)
if (!drv) {
return false;
}
if (drv->bdrv_is_inserted) {
return drv->bdrv_is_inserted(bs);
if (drv->bdrv_co_is_inserted) {
return drv->bdrv_co_is_inserted(bs);
}
QLIST_FOREACH(child, &bs->children, next) {
if (!bdrv_is_inserted(child->bs)) {
if (!bdrv_co_is_inserted(child->bs)) {
return false;
}
}

View File

@ -1983,12 +1983,12 @@ void blk_activate(BlockBackend *blk, Error **errp)
bdrv_activate(bs, errp);
}
bool blk_is_inserted(BlockBackend *blk)
bool coroutine_fn blk_co_is_inserted(BlockBackend *blk)
{
BlockDriverState *bs = blk_bs(blk);
IO_CODE();
return bs && bdrv_is_inserted(bs);
return bs && bdrv_co_is_inserted(bs);
}
bool blk_is_available(BlockBackend *blk)

View File

@ -3757,7 +3757,7 @@ out:
return prio;
}
static bool cdrom_is_inserted(BlockDriverState *bs)
static bool coroutine_fn cdrom_co_is_inserted(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
int ret;
@ -3824,7 +3824,7 @@ static BlockDriver bdrv_host_cdrom = {
= raw_get_allocated_file_size,
/* removable device support */
.bdrv_is_inserted = cdrom_is_inserted,
.bdrv_co_is_inserted = cdrom_co_is_inserted,
.bdrv_eject = cdrom_eject,
.bdrv_lock_medium = cdrom_lock_medium,
@ -3883,7 +3883,7 @@ static int cdrom_reopen(BlockDriverState *bs)
return 0;
}
static bool cdrom_is_inserted(BlockDriverState *bs)
static bool coroutine_fn cdrom_co_is_inserted(BlockDriverState *bs)
{
return raw_getlength(bs) > 0;
}
@ -3954,7 +3954,7 @@ static BlockDriver bdrv_host_cdrom = {
= raw_get_allocated_file_size,
/* removable device support */
.bdrv_is_inserted = cdrom_is_inserted,
.bdrv_co_is_inserted = cdrom_co_is_inserted,
.bdrv_eject = cdrom_eject,
.bdrv_lock_medium = cdrom_lock_medium,
};

View File

@ -1622,7 +1622,7 @@ int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
trace_bdrv_co_preadv_part(bs, offset, bytes, flags);
if (!bdrv_is_inserted(bs)) {
if (!bdrv_co_is_inserted(bs)) {
return -ENOMEDIUM;
}
@ -2067,7 +2067,7 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
trace_bdrv_co_pwritev_part(child->bs, offset, bytes, flags);
if (!bdrv_is_inserted(bs)) {
if (!bdrv_co_is_inserted(bs)) {
return -ENOMEDIUM;
}
@ -2835,7 +2835,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
bdrv_inc_in_flight(bs);
if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs) ||
if (!bdrv_co_is_inserted(bs) || bdrv_is_read_only(bs) ||
bdrv_is_sg(bs)) {
goto early_exit;
}
@ -2959,7 +2959,7 @@ int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, int64_t offset,
BlockDriverState *bs = child->bs;
IO_CODE();
if (!bs || !bs->drv || !bdrv_is_inserted(bs)) {
if (!bs || !bs->drv || !bdrv_co_is_inserted(bs)) {
return -ENOMEDIUM;
}
@ -3241,7 +3241,7 @@ static int coroutine_fn bdrv_co_copy_range_internal(
assert(!(read_flags & BDRV_REQ_NO_WAIT));
assert(!(write_flags & BDRV_REQ_NO_WAIT));
if (!dst || !dst->bs || !bdrv_is_inserted(dst->bs)) {
if (!dst || !dst->bs || !bdrv_co_is_inserted(dst->bs)) {
return -ENOMEDIUM;
}
ret = bdrv_check_request32(dst_offset, bytes, NULL, 0);
@ -3252,7 +3252,7 @@ static int coroutine_fn bdrv_co_copy_range_internal(
return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, write_flags);
}
if (!src || !src->bs || !bdrv_is_inserted(src->bs)) {
if (!src || !src->bs || !bdrv_co_is_inserted(src->bs)) {
return -ENOMEDIUM;
}
ret = bdrv_check_request32(src_offset, bytes, NULL, 0);

View File

@ -1024,6 +1024,7 @@ fail:
static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp)
{
BlockDriverState *bs;
AioContext *aio_context;
bs = bdrv_lookup_bs(name, name, errp);
if (bs == NULL) {
@ -1035,11 +1036,16 @@ static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp)
return NULL;
}
aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);
if (!bdrv_is_inserted(bs)) {
error_setg(errp, "Device has no medium");
return NULL;
bs = NULL;
}
aio_context_release(aio_context);
return bs;
}

View File

@ -136,7 +136,10 @@ bool bdrv_is_read_only(BlockDriverState *bs);
bool bdrv_is_writable(BlockDriverState *bs);
bool bdrv_is_sg(BlockDriverState *bs);
int bdrv_get_flags(BlockDriverState *bs);
bool bdrv_is_inserted(BlockDriverState *bs);
bool coroutine_fn bdrv_co_is_inserted(BlockDriverState *bs);
bool co_wrapper bdrv_is_inserted(BlockDriverState *bs);
void bdrv_lock_medium(BlockDriverState *bs, bool locked);
void bdrv_eject(BlockDriverState *bs, bool eject_flag);
const char *bdrv_get_format_name(BlockDriverState *bs);

View File

@ -704,7 +704,7 @@ struct BlockDriver {
BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
/* removable device specific */
bool (*bdrv_is_inserted)(BlockDriverState *bs);
bool coroutine_fn (*bdrv_co_is_inserted)(BlockDriverState *bs);
void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);

View File

@ -54,7 +54,10 @@ BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
void blk_inc_in_flight(BlockBackend *blk);
void blk_dec_in_flight(BlockBackend *blk);
bool blk_is_inserted(BlockBackend *blk);
bool coroutine_fn blk_co_is_inserted(BlockBackend *blk);
bool co_wrapper_mixed blk_is_inserted(BlockBackend *blk);
bool blk_is_available(BlockBackend *blk);
void blk_lock_medium(BlockBackend *blk, bool locked);
void blk_eject(BlockBackend *blk, bool eject_flag);