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[Qemu-devel] [PATCH 12/23] qcow2: Finalise interface of handle_alloc()
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PATCH 12/23] qcow2: Finalise interface of handle_alloc() |
Date: |
Thu, 28 Mar 2013 17:40:26 +0100 |
From: Kevin Wolf <address@hidden>
The interface works completely on a byte granularity now and duplicated
parameters are removed.
Signed-off-by: Kevin Wolf <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
block/qcow2-cluster.c | 29 ++++++++++++++++-------------
block/qcow2.h | 5 +++++
2 files changed, 21 insertions(+), 13 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 8f4ef0d..8ed1f7d 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -875,13 +875,9 @@ static int do_alloc_cluster_offset(BlockDriverState *bs,
uint64_t guest_offset,
* newly allocated cluster.
*
* -errno: in error cases
- *
- * TODO Get rid of n_start, n_end
- * TODO Make *bytes actually behave as specified above
*/
static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
- uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m,
- int n_start, int n_end)
+ uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m)
{
BDRVQcowState *s = bs->opaque;
int l2_index;
@@ -901,8 +897,11 @@ static int handle_alloc(BlockDriverState *bs, uint64_t
guest_offset,
* Calculate the number of clusters to look for. We stop at L2 table
* boundaries to keep things simple.
*/
+ nb_clusters =
+ size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes);
+
l2_index = offset_to_l2_index(s, guest_offset);
- nb_clusters = MIN(size_to_clusters(s, *bytes), s->l2_size - l2_index);
+ nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
/* Find L2 entry for the first involved cluster */
ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index);
@@ -954,10 +953,13 @@ static int handle_alloc(BlockDriverState *bs, uint64_t
guest_offset,
* newly allocated cluster to the end of the aread that the write
* request actually writes to (excluding COW at the end)
*/
- int requested_sectors = n_end;
+ int requested_sectors =
+ (*bytes + offset_into_cluster(s, guest_offset))
+ >> BDRV_SECTOR_BITS;
int avail_sectors = nb_clusters
<< (s->cluster_bits - BDRV_SECTOR_BITS);
- int alloc_n_start = *host_offset == 0 ? n_start : 0;
+ int alloc_n_start = offset_into_cluster(s, guest_offset)
+ >> BDRV_SECTOR_BITS;
int nb_sectors = MIN(requested_sectors, avail_sectors);
if (*host_offset == 0) {
@@ -984,7 +986,9 @@ static int handle_alloc(BlockDriverState *bs, uint64_t
guest_offset,
qemu_co_queue_init(&(*m)->dependent_requests);
QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight);
- *bytes = nb_clusters * s->cluster_size;
+ *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE)
+ - offset_into_cluster(s, guest_offset));
+ assert(*bytes != 0);
} else {
*bytes = 0;
return 0;
@@ -1139,10 +1143,9 @@ again:
alloc_n_end = n_end;
}
- cur_bytes = nb_clusters * s->cluster_size;
+ cur_bytes = MIN(cur_bytes, ((alloc_n_end - alloc_n_start) <<
BDRV_SECTOR_BITS));
- ret = handle_alloc(bs, offset, &cluster_offset, &cur_bytes, m,
- alloc_n_start, alloc_n_end);
+ ret = handle_alloc(bs, offset, &cluster_offset, &cur_bytes, m);
if (ret < 0) {
return ret;
}
@@ -1150,7 +1153,7 @@ again:
if (!*host_offset) {
*host_offset = cluster_offset;
}
- nb_clusters = size_to_clusters(s, cur_bytes);
+ nb_clusters = size_to_clusters(s, cur_bytes + offset_into_cluster(s,
offset));
/* Some cleanup work */
done:
diff --git a/block/qcow2.h b/block/qcow2.h
index c4eaf67..32806bd 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -271,6 +271,11 @@ static inline int64_t start_of_cluster(BDRVQcowState *s,
int64_t offset)
return offset & ~(s->cluster_size - 1);
}
+static inline int64_t offset_into_cluster(BDRVQcowState *s, int64_t offset)
+{
+ return offset & (s->cluster_size - 1);
+}
+
static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
{
return (size + (s->cluster_size - 1)) >> s->cluster_bits;
--
1.8.1.4
- [Qemu-devel] [PATCH 01/23] vl.c: call bdrv_init_with_whitelist() before cmdline parsing, (continued)
- [Qemu-devel] [PATCH 01/23] vl.c: call bdrv_init_with_whitelist() before cmdline parsing, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 05/23] qcow2: Handle dependencies earlier, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 03/23] qcow2: Fix "total clusters" number in bdrv_check, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 04/23] qcow2: Remove bogus unlock of s->lock, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 06/23] qcow2: Improve check for overlapping allocations, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 08/23] qcow2: Decouple cluster allocation from cluster reuse code, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 07/23] qcow2: Change handle_dependency to byte granularity, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 09/23] qcow2: Factor out handle_alloc(), Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 11/23] qcow2: handle_alloc(): Get rid of keep_clusters parameter, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 10/23] qcow2: handle_alloc(): Get rid of nb_clusters parameter, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 12/23] qcow2: Finalise interface of handle_alloc(),
Stefan Hajnoczi <=
- [Qemu-devel] [PATCH 13/23] qcow2: Clean up handle_alloc(), Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 14/23] qcow2: Factor out handle_copied(), Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 15/23] qcow2: handle_copied(): Get rid of nb_clusters parameter, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 16/23] qcow2: handle_copied(): Get rid of keep_clusters parameter, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 18/23] qcow2: Prepare handle_alloc/copied() for byte granularity, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 17/23] qcow2: handle_copied(): Implement non-zero host_offset, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 19/23] qcow2: Use byte granularity in qcow2_alloc_cluster_offset(), Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 20/23] qcow2: Allow requests with multiple l2metas, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 21/23] qcow2: Move cluster gathering to a non-looping loop, Stefan Hajnoczi, 2013/03/28
- [Qemu-devel] [PATCH 22/23] qcow2: Gather clusters in a looping loop, Stefan Hajnoczi, 2013/03/28