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aef4acb661
A BlockDriverState should not issue requests on itself through the public block layer interface. Nested, or reentrant, requests are problematic because they do I/O throttling and request tracking twice. Features like block layer copy-on-read use request tracking to avoid race conditions between concurrent requests. The reentrant request will have to "wait" for its parent request to complete. But the parent is waiting for the reentrant request to make progress so we have reached deadlock. The solution is for block drivers to avoid the public block layer interfaces for reentrant requests. Instead they should call their own internal functions if they wish to perform reentrant requests. This is also a good opportunity to make copy_sectors() a true coroutine_fn. That means calling bdrv_co_writev() instead of bdrv_write(). Behavior is unchanged but we're being explicit that this executes in coroutine context. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
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| .. | ||
| blkdebug.c | ||
| blkverify.c | ||
| bochs.c | ||
| cloop.c | ||
| cow.c | ||
| curl.c | ||
| dmg.c | ||
| iscsi.c | ||
| nbd.c | ||
| parallels.c | ||
| qcow.c | ||
| qcow2-cache.c | ||
| qcow2-cluster.c | ||
| qcow2-refcount.c | ||
| qcow2-snapshot.c | ||
| qcow2.c | ||
| qcow2.h | ||
| qed-check.c | ||
| qed-cluster.c | ||
| qed-gencb.c | ||
| qed-l2-cache.c | ||
| qed-table.c | ||
| qed.c | ||
| qed.h | ||
| raw-posix-aio.h | ||
| raw-posix.c | ||
| raw-win32.c | ||
| raw.c | ||
| rbd.c | ||
| sheepdog.c | ||
| vdi.c | ||
| vmdk.c | ||
| vpc.c | ||
| vvfat.c | ||