Commit 0d09c797 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Kevin Wolf
Browse files

qed: Images with backing file do not require QED_F_NEED_CHECK



The consistency check on open is necessary in order to fix inconsistent
table offsets left as a result of a crash mid-operation.  Images with a
backing file actually flush before updating table offsets and are
therefore guaranteed to be consistent.  Do not mark these images dirty.

Signed-off-by: default avatarStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 5ea929e3
......@@ -976,6 +976,19 @@ static void qed_aio_write_prefill(void *opaque, int ret)
qed_aio_write_postfill, acb);
}
/**
* Check if the QED_F_NEED_CHECK bit should be set during allocating write
*/
static bool qed_should_set_need_check(BDRVQEDState *s)
{
/* The flush before L2 update path ensures consistency */
if (s->bs->backing_hd) {
return false;
}
return !(s->header.features & QED_F_NEED_CHECK);
}
/**
* Write new data cluster
*
......@@ -1001,15 +1014,12 @@ static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len)
acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters);
qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
/* Write new cluster if the image is already marked dirty */
if (s->header.features & QED_F_NEED_CHECK) {
if (qed_should_set_need_check(s)) {
s->header.features |= QED_F_NEED_CHECK;
qed_write_header(s, qed_aio_write_prefill, acb);
} else {
qed_aio_write_prefill(acb, 0);
return;
}
/* Mark the image dirty before writing the new cluster */
s->header.features |= QED_F_NEED_CHECK;
qed_write_header(s, qed_aio_write_prefill, acb);
}
/**
......
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