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[Qemu-devel] [STABLE][PATCH 02/14] qcow2: Fix creation of large images
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [STABLE][PATCH 02/14] qcow2: Fix creation of large images |
Date: |
Wed, 14 Jul 2010 13:24:01 +0200 |
qcow_create2 assumes that the new image will only need one cluster for its
refcount table initially. Obviously that's not true any more when the image is
big enough (exact value depends on the cluster size).
This patch calculates the refcount table size dynamically.
Signed-off-by: Kevin Wolf <address@hidden>
(cherry picked from commit 4768fa902c3860f2fe34403e6e1c83bfca6da034)
Conflicts:
block/qcow2.c
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2.c | 41 ++++++++++++++++++++++++++++++++---------
1 files changed, 32 insertions(+), 9 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 5d33d6c..35c05e0 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -747,10 +747,11 @@ static int qcow_create2(const char *filename, int64_t
total_size,
{
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
- int ref_clusters, backing_format_len = 0;
+ int ref_clusters, reftable_clusters, backing_format_len = 0;
int rounded_ext_bf_len = 0;
QCowHeader header;
uint64_t tmp, offset;
+ uint64_t old_ref_clusters;
QCowCreateState s1, *s = &s1;
QCowExtension ext_bf = {0, 0};
@@ -809,17 +810,37 @@ static int qcow_create2(const char *filename, int64_t
total_size,
header.l1_size = cpu_to_be32(l1_size);
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
- s->refcount_table = qemu_mallocz(s->cluster_size);
+ /* count how many refcount blocks needed */
+
+#define NUM_CLUSTERS(bytes) \
+ (((bytes) + (s->cluster_size) - 1) / (s->cluster_size))
+
+ ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t));
+
+ do {
+ uint64_t image_clusters;
+ old_ref_clusters = ref_clusters;
+
+ /* Number of clusters used for the refcount table */
+ reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t));
+
+ /* Number of clusters that the whole image will have */
+ image_clusters = NUM_CLUSTERS(offset) + ref_clusters
+ + reftable_clusters;
+
+ /* Number of refcount blocks needed for the image */
+ ref_clusters = NUM_CLUSTERS(image_clusters * sizeof(uint16_t));
+
+ } while (ref_clusters != old_ref_clusters);
+
+ s->refcount_table = qemu_mallocz(reftable_clusters * s->cluster_size);
s->refcount_table_offset = offset;
header.refcount_table_offset = cpu_to_be64(offset);
- header.refcount_table_clusters = cpu_to_be32(1);
- offset += s->cluster_size;
+ header.refcount_table_clusters = cpu_to_be32(reftable_clusters);
+ offset += (reftable_clusters * s->cluster_size);
s->refcount_block_offset = offset;
- /* count how many refcount blocks needed */
- tmp = offset >> s->cluster_bits;
- ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1;
for (i=0; i < ref_clusters; i++) {
s->refcount_table[i] = cpu_to_be64(offset);
offset += s->cluster_size;
@@ -831,7 +852,8 @@ static int qcow_create2(const char *filename, int64_t
total_size,
qcow2_create_refcount_update(s, 0, header_size);
qcow2_create_refcount_update(s, s->l1_table_offset,
l1_size * sizeof(uint64_t));
- qcow2_create_refcount_update(s, s->refcount_table_offset, s->cluster_size);
+ qcow2_create_refcount_update(s, s->refcount_table_offset,
+ reftable_clusters * s->cluster_size);
qcow2_create_refcount_update(s, s->refcount_block_offset,
ref_clusters * s->cluster_size);
@@ -859,7 +881,8 @@ static int qcow_create2(const char *filename, int64_t
total_size,
write(fd, &tmp, sizeof(tmp));
}
lseek(fd, s->refcount_table_offset, SEEK_SET);
- write(fd, s->refcount_table, s->cluster_size);
+ write(fd, s->refcount_table,
+ reftable_clusters * s->cluster_size);
lseek(fd, s->refcount_block_offset, SEEK_SET);
write(fd, s->refcount_block, ref_clusters * s->cluster_size);
--
1.7.1.1
- [Qemu-devel] [STABLE][PULL 00/14] Block patches for 0.12.5, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 01/14] vmdk: fix double free, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 04/14] qcow2: Remove abort on free_clusters failure, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 03/14] vmdk: Fix COW, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 02/14] qcow2: Fix creation of large images,
Kevin Wolf <=
- [Qemu-devel] [STABLE][PATCH 05/14] block/vpc: Fix conversion from size to disk geometry, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 06/14] block/vdi: Fix image opening and creation for odd disk sizes, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 07/14] qcow2: Restore L1 entry on l2_allocate failure, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 09/14] qcow: Use bdrv_(p)write_sync for metadata writes, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 08/14] block: Add bdrv_(p)write_sync, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 11/14] vmdk: Use bdrv_(p)write_sync for metadata writes, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 10/14] qcow2: Use bdrv_(p)write_sync for metadata writes, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 13/14] block: Fix early failure in multiwrite, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 14/14] block: Handle multiwrite errors only when all requests have completed, Kevin Wolf, 2010/07/14
- [Qemu-devel] [STABLE][PATCH 12/14] vpc: Use bdrv_(p)write_sync for metadata writes, Kevin Wolf, 2010/07/14