c86422c554
BlockDriver->bdrv_getlength is categorized as IO callback, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since the callback 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. 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 co_wrapper calls AIO_WAIT_WHILE and it expects to release the AioContext lock. This is especially messy when a co_wrapper creates a coroutine and polls in bdrv_open_driver, because this function has so many callers in so many context that it can easily lead to deadlocks. Therefore the new rule for bdrv_open_driver is that the caller must always hold the AioContext lock of the given bs (except if it is a coroutine), because the function calls bdrv_refresh_total_sectors() which is now a co_wrapper. 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: <20230113204212.359076-7-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
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| .. | ||
| emulation.c | ||
| esp-pci.c | ||
| esp.c | ||
| Kconfig | ||
| lsi53c895a.c | ||
| megasas.c | ||
| meson.build | ||
| mfi.h | ||
| mpi.h | ||
| mptconfig.c | ||
| mptendian.c | ||
| mptsas.c | ||
| mptsas.h | ||
| scsi-bus.c | ||
| scsi-disk.c | ||
| scsi-generic.c | ||
| spapr_vscsi.c | ||
| srp.h | ||
| trace-events | ||
| trace.h | ||
| vhost-scsi-common.c | ||
| vhost-scsi.c | ||
| vhost-user-scsi.c | ||
| viosrp.h | ||
| virtio-scsi-dataplane.c | ||
| virtio-scsi.c | ||
| vmw_pvscsi.c | ||
| vmw_pvscsi.h | ||