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[Qemu-devel] [PATCH 13/23] qcow2: Clean up handle_alloc()
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PATCH 13/23] qcow2: Clean up handle_alloc() |
Date: |
Thu, 28 Mar 2013 17:40:27 +0100 |
From: Kevin Wolf <address@hidden>
Things can be simplified a bit now. No semantic changes.
Signed-off-by: Kevin Wolf <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
block/qcow2-cluster.c | 110 ++++++++++++++++++++++++--------------------------
1 file changed, 53 insertions(+), 57 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 8ed1f7d..1141483 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -886,7 +886,6 @@ static int handle_alloc(BlockDriverState *bs, uint64_t
guest_offset,
unsigned int nb_clusters;
int ret;
- uint64_t alloc_offset;
uint64_t alloc_cluster_offset;
trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset,
@@ -928,72 +927,69 @@ static int handle_alloc(BlockDriverState *bs, uint64_t
guest_offset,
return 0;
}
- /* Calculate start and size of allocation */
- alloc_offset = guest_offset;
- alloc_cluster_offset = *host_offset;
-
/* Allocate, if necessary at a given offset in the image file */
- ret = do_alloc_cluster_offset(bs, alloc_offset, &alloc_cluster_offset,
+ alloc_cluster_offset = *host_offset;
+ ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset,
&nb_clusters);
if (ret < 0) {
goto fail;
}
- /* save info needed for meta data update */
- if (nb_clusters > 0) {
- /*
- * requested_sectors: Number of sectors from the start of the first
- * newly allocated cluster to the end of the (possibly shortened
- * before) write request.
- *
- * avail_sectors: Number of sectors from the start of the first
- * newly allocated to the end of the last newly allocated cluster.
- *
- * nb_sectors: The number of sectors from the start of the first
- * newly allocated cluster to the end of the aread that the write
- * request actually writes to (excluding COW at the 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 = offset_into_cluster(s, guest_offset)
- >> BDRV_SECTOR_BITS;
- int nb_sectors = MIN(requested_sectors, avail_sectors);
-
- if (*host_offset == 0) {
- *host_offset = alloc_cluster_offset;
- }
-
- *m = g_malloc0(sizeof(**m));
-
- **m = (QCowL2Meta) {
- .alloc_offset = alloc_cluster_offset,
- .offset = alloc_offset & ~(s->cluster_size - 1),
- .nb_clusters = nb_clusters,
- .nb_available = nb_sectors,
-
- .cow_start = {
- .offset = 0,
- .nb_sectors = alloc_n_start,
- },
- .cow_end = {
- .offset = nb_sectors * BDRV_SECTOR_SIZE,
- .nb_sectors = avail_sectors - nb_sectors,
- },
- };
- qemu_co_queue_init(&(*m)->dependent_requests);
- QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight);
-
- *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE)
- - offset_into_cluster(s, guest_offset));
- assert(*bytes != 0);
- } else {
+ /* Can't extend contiguous allocation */
+ if (nb_clusters == 0) {
*bytes = 0;
return 0;
}
+ /*
+ * Save info needed for meta data update.
+ *
+ * requested_sectors: Number of sectors from the start of the first
+ * newly allocated cluster to the end of the (possibly shortened
+ * before) write request.
+ *
+ * avail_sectors: Number of sectors from the start of the first
+ * newly allocated to the end of the last newly allocated cluster.
+ *
+ * nb_sectors: The number of sectors from the start of the first
+ * newly allocated cluster to the end of the area that the write
+ * request actually writes to (excluding COW at the 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 = offset_into_cluster(s, guest_offset)
+ >> BDRV_SECTOR_BITS;
+ int nb_sectors = MIN(requested_sectors, avail_sectors);
+
+ *host_offset = alloc_cluster_offset;
+
+ *m = g_malloc0(sizeof(**m));
+
+ **m = (QCowL2Meta) {
+ .alloc_offset = *host_offset,
+ .offset = start_of_cluster(s, guest_offset),
+ .nb_clusters = nb_clusters,
+ .nb_available = nb_sectors,
+
+ .cow_start = {
+ .offset = 0,
+ .nb_sectors = alloc_n_start,
+ },
+ .cow_end = {
+ .offset = nb_sectors * BDRV_SECTOR_SIZE,
+ .nb_sectors = avail_sectors - nb_sectors,
+ },
+ };
+ qemu_co_queue_init(&(*m)->dependent_requests);
+ QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight);
+
+ *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE)
+ - offset_into_cluster(s, guest_offset));
+ assert(*bytes != 0);
+
return 1;
fail:
--
1.8.1.4
- [Qemu-devel] [PATCH 05/23] qcow2: Handle dependencies earlier, (continued)
- [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, 2013/03/28
- [Qemu-devel] [PATCH 13/23] qcow2: Clean up handle_alloc(),
Stefan Hajnoczi <=
- [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
- [Qemu-devel] [PATCH 23/23] block: Fix direct use of protocols as driver for bdrv_open(), Stefan Hajnoczi, 2013/03/28