From: Alberto Garcia <berto@igalia.com>
To: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
Alberto Garcia <berto@igalia.com>,
qemu-block@nongnu.org, Derek Su <dereksu@qnap.com>,
Max Reitz <mreitz@redhat.com>
Subject: [PATCH v9 21/34] qcow2: Add subcluster support to qcow2_get_host_offset()
Date: Sun, 28 Jun 2020 13:02:30 +0200 [thread overview]
Message-ID: <d82b7e4829f466eda81f3a33b536dde43aa3e26a.1593342067.git.berto@igalia.com> (raw)
In-Reply-To: <cover.1593342067.git.berto@igalia.com>
The logic of this function remains pretty much the same, except that
it uses count_contiguous_subclusters(), which combines the logic of
count_contiguous_clusters() / count_contiguous_clusters_unallocated()
and checks individual subclusters.
qcow2_cluster_to_subcluster_type() is not necessary as a separate
function anymore so it's inlined into its caller.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
block/qcow2.h | 38 ++++-------
block/qcow2-cluster.c | 150 ++++++++++++++++++++++--------------------
2 files changed, 92 insertions(+), 96 deletions(-)
diff --git a/block/qcow2.h b/block/qcow2.h
index 5df761edc3..4fad40b96b 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -710,29 +710,6 @@ static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
}
}
-/*
- * For an image without extended L2 entries, return the
- * QCow2SubclusterType equivalent of a given QCow2ClusterType.
- */
-static inline
-QCow2SubclusterType qcow2_cluster_to_subcluster_type(QCow2ClusterType type)
-{
- switch (type) {
- case QCOW2_CLUSTER_COMPRESSED:
- return QCOW2_SUBCLUSTER_COMPRESSED;
- case QCOW2_CLUSTER_ZERO_PLAIN:
- return QCOW2_SUBCLUSTER_ZERO_PLAIN;
- case QCOW2_CLUSTER_ZERO_ALLOC:
- return QCOW2_SUBCLUSTER_ZERO_ALLOC;
- case QCOW2_CLUSTER_NORMAL:
- return QCOW2_SUBCLUSTER_NORMAL;
- case QCOW2_CLUSTER_UNALLOCATED:
- return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
- default:
- g_assert_not_reached();
- }
-}
-
/*
* In an image without subsclusters @l2_bitmap is ignored and
* @sc_index must be 0.
@@ -776,7 +753,20 @@ QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
g_assert_not_reached();
}
} else {
- return qcow2_cluster_to_subcluster_type(type);
+ switch (type) {
+ case QCOW2_CLUSTER_COMPRESSED:
+ return QCOW2_SUBCLUSTER_COMPRESSED;
+ case QCOW2_CLUSTER_ZERO_PLAIN:
+ return QCOW2_SUBCLUSTER_ZERO_PLAIN;
+ case QCOW2_CLUSTER_ZERO_ALLOC:
+ return QCOW2_SUBCLUSTER_ZERO_ALLOC;
+ case QCOW2_CLUSTER_NORMAL:
+ return QCOW2_SUBCLUSTER_NORMAL;
+ case QCOW2_CLUSTER_UNALLOCATED:
+ return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
+ default:
+ g_assert_not_reached();
+ }
}
}
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 59dd9bda29..2f3bd3a882 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -426,66 +426,66 @@ static int qcow2_get_subcluster_range_type(BlockDriverState *bs,
}
/*
- * Checks how many clusters in a given L2 slice are contiguous in the image
- * file. As soon as one of the flags in the bitmask stop_flags changes compared
- * to the first cluster, the search is stopped and the cluster is not counted
- * as contiguous. (This allows it, for example, to stop at the first compressed
- * cluster which may require a different handling)
+ * Return the number of contiguous subclusters of the exact same type
+ * in a given L2 slice, starting from cluster @l2_index, subcluster
+ * @sc_index. Allocated subclusters are required to be contiguous in
+ * the image file.
+ * At most @nb_clusters are checked (note that this means clusters,
+ * not subclusters).
+ * Compressed clusters are always processed one by one but for the
+ * purpose of this count they are treated as if they were divided into
+ * subclusters of size s->subcluster_size.
+ * On failure return -errno and update @l2_index to point to the
+ * invalid entry.
*/
-static int count_contiguous_clusters(BlockDriverState *bs, int nb_clusters,
- int cluster_size, uint64_t *l2_slice, int l2_index, uint64_t stop_flags)
+static int count_contiguous_subclusters(BlockDriverState *bs, int nb_clusters,
+ unsigned sc_index, uint64_t *l2_slice,
+ unsigned *l2_index)
{
BDRVQcow2State *s = bs->opaque;
- int i;
- QCow2ClusterType first_cluster_type;
- uint64_t mask = stop_flags | L2E_OFFSET_MASK | QCOW_OFLAG_COMPRESSED;
- uint64_t first_entry = get_l2_entry(s, l2_slice, l2_index);
- uint64_t offset = first_entry & mask;
+ int i, count = 0;
+ bool check_offset;
+ uint64_t expected_offset;
+ QCow2SubclusterType expected_type, type;
- first_cluster_type = qcow2_get_cluster_type(bs, first_entry);
- if (first_cluster_type == QCOW2_CLUSTER_UNALLOCATED) {
- return 0;
- }
-
- /* must be allocated */
- assert(first_cluster_type == QCOW2_CLUSTER_NORMAL ||
- first_cluster_type == QCOW2_CLUSTER_ZERO_ALLOC);
+ assert(*l2_index + nb_clusters <= s->l2_size);
for (i = 0; i < nb_clusters; i++) {
- uint64_t l2_entry = get_l2_entry(s, l2_slice, l2_index + i) & mask;
- if (offset + (uint64_t) i * cluster_size != l2_entry) {
+ unsigned first_sc = (i == 0) ? sc_index : 0;
+ uint64_t l2_entry = get_l2_entry(s, l2_slice, *l2_index + i);
+ uint64_t l2_bitmap = get_l2_bitmap(s, l2_slice, *l2_index + i);
+ int ret = qcow2_get_subcluster_range_type(bs, l2_entry, l2_bitmap,
+ first_sc, &type);
+ if (ret < 0) {
+ *l2_index += i; /* Point to the invalid entry */
+ return -EIO;
+ }
+ if (i == 0) {
+ if (type == QCOW2_SUBCLUSTER_COMPRESSED) {
+ /* Compressed clusters are always processed one by one */
+ return ret;
+ }
+ expected_type = type;
+ expected_offset = l2_entry & L2E_OFFSET_MASK;
+ check_offset = (type == QCOW2_SUBCLUSTER_NORMAL ||
+ type == QCOW2_SUBCLUSTER_ZERO_ALLOC ||
+ type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC);
+ } else if (type != expected_type) {
break;
+ } else if (check_offset) {
+ expected_offset += s->cluster_size;
+ if (expected_offset != (l2_entry & L2E_OFFSET_MASK)) {
+ break;
+ }
}
- }
-
- return i;
-}
-
-/*
- * Checks how many consecutive unallocated clusters in a given L2
- * slice have the same cluster type.
- */
-static int count_contiguous_clusters_unallocated(BlockDriverState *bs,
- int nb_clusters,
- uint64_t *l2_slice,
- int l2_index,
- QCow2ClusterType wanted_type)
-{
- BDRVQcow2State *s = bs->opaque;
- int i;
-
- assert(wanted_type == QCOW2_CLUSTER_ZERO_PLAIN ||
- wanted_type == QCOW2_CLUSTER_UNALLOCATED);
- for (i = 0; i < nb_clusters; i++) {
- uint64_t entry = get_l2_entry(s, l2_slice, l2_index + i);
- QCow2ClusterType type = qcow2_get_cluster_type(bs, entry);
-
- if (type != wanted_type) {
+ count += ret;
+ /* Stop if there are type changes before the end of the cluster */
+ if (first_sc + ret < s->subclusters_per_cluster) {
break;
}
}
- return i;
+ return count;
}
static int coroutine_fn do_perform_cow_read(BlockDriverState *bs,
@@ -574,12 +574,12 @@ int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
QCow2SubclusterType *subcluster_type)
{
BDRVQcow2State *s = bs->opaque;
- unsigned int l2_index;
- uint64_t l1_index, l2_offset, *l2_slice, l2_entry;
- int c;
+ unsigned int l2_index, sc_index;
+ uint64_t l1_index, l2_offset, *l2_slice, l2_entry, l2_bitmap;
+ int sc;
unsigned int offset_in_cluster;
uint64_t bytes_available, bytes_needed, nb_clusters;
- QCow2ClusterType type;
+ QCow2SubclusterType type;
int ret;
offset_in_cluster = offset_into_cluster(s, offset);
@@ -600,13 +600,13 @@ int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
l1_index = offset_to_l1_index(s, offset);
if (l1_index >= s->l1_size) {
- type = QCOW2_CLUSTER_UNALLOCATED;
+ type = QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
goto out;
}
l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK;
if (!l2_offset) {
- type = QCOW2_CLUSTER_UNALLOCATED;
+ type = QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
goto out;
}
@@ -627,7 +627,9 @@ int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
/* find the cluster offset for the given disk offset */
l2_index = offset_to_l2_slice_index(s, offset);
+ sc_index = offset_to_sc_index(s, offset);
l2_entry = get_l2_entry(s, l2_slice, l2_index);
+ l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index);
nb_clusters = size_to_clusters(s, bytes_needed);
/* bytes_needed <= *bytes + offset_in_cluster, both of which are unsigned
@@ -635,9 +637,9 @@ int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
* true */
assert(nb_clusters <= INT_MAX);
- type = qcow2_get_cluster_type(bs, l2_entry);
- if (s->qcow_version < 3 && (type == QCOW2_CLUSTER_ZERO_PLAIN ||
- type == QCOW2_CLUSTER_ZERO_ALLOC)) {
+ type = qcow2_get_subcluster_type(bs, l2_entry, l2_bitmap, sc_index);
+ if (s->qcow_version < 3 && (type == QCOW2_SUBCLUSTER_ZERO_PLAIN ||
+ type == QCOW2_SUBCLUSTER_ZERO_ALLOC)) {
qcow2_signal_corruption(bs, true, -1, -1, "Zero cluster entry found"
" in pre-v3 image (L2 offset: %#" PRIx64
", L2 index: %#x)", l2_offset, l2_index);
@@ -645,7 +647,9 @@ int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
goto fail;
}
switch (type) {
- case QCOW2_CLUSTER_COMPRESSED:
+ case QCOW2_SUBCLUSTER_INVALID:
+ break; /* This is handled by count_contiguous_subclusters() below */
+ case QCOW2_SUBCLUSTER_COMPRESSED:
if (has_data_file(bs)) {
qcow2_signal_corruption(bs, true, -1, -1, "Compressed cluster "
"entry found in image with external data "
@@ -654,24 +658,17 @@ int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
ret = -EIO;
goto fail;
}
- /* Compressed clusters can only be processed one by one */
- c = 1;
*host_offset = l2_entry & L2E_COMPRESSED_OFFSET_SIZE_MASK;
break;
- case QCOW2_CLUSTER_ZERO_PLAIN:
- case QCOW2_CLUSTER_UNALLOCATED:
- /* how many empty clusters ? */
- c = count_contiguous_clusters_unallocated(bs, nb_clusters,
- l2_slice, l2_index, type);
+ case QCOW2_SUBCLUSTER_ZERO_PLAIN:
+ case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN:
*host_offset = 0;
break;
- case QCOW2_CLUSTER_ZERO_ALLOC:
- case QCOW2_CLUSTER_NORMAL: {
+ case QCOW2_SUBCLUSTER_ZERO_ALLOC:
+ case QCOW2_SUBCLUSTER_NORMAL:
+ case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: {
uint64_t host_cluster_offset = l2_entry & L2E_OFFSET_MASK;
*host_offset = host_cluster_offset + offset_in_cluster;
- /* how many allocated clusters ? */
- c = count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
- l2_slice, l2_index, QCOW_OFLAG_ZERO);
if (offset_into_cluster(s, host_cluster_offset)) {
qcow2_signal_corruption(bs, true, -1, -1,
"Cluster allocation offset %#"
@@ -697,9 +694,18 @@ int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
abort();
}
+ sc = count_contiguous_subclusters(bs, nb_clusters, sc_index,
+ l2_slice, &l2_index);
+ if (sc < 0) {
+ qcow2_signal_corruption(bs, true, -1, -1, "Invalid cluster entry found "
+ " (L2 offset: %#" PRIx64 ", L2 index: %#x)",
+ l2_offset, l2_index);
+ ret = -EIO;
+ goto fail;
+ }
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- bytes_available = (int64_t)c * s->cluster_size;
+ bytes_available = ((int64_t)sc + sc_index) << s->subcluster_bits;
out:
if (bytes_available > bytes_needed) {
@@ -712,7 +718,7 @@ out:
assert(bytes_available - offset_in_cluster <= UINT_MAX);
*bytes = bytes_available - offset_in_cluster;
- *subcluster_type = qcow2_cluster_to_subcluster_type(type);
+ *subcluster_type = type;
return 0;
--
2.20.1
next prev parent reply other threads:[~2020-06-28 11:24 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-28 11:02 [PATCH v9 00/34] Add subcluster allocation to qcow2 Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 01/34] qcow2: Make Qcow2AioTask store the full host offset Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 02/34] qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset() Alberto Garcia
2020-06-30 10:19 ` Max Reitz
2020-06-30 10:27 ` Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 03/34] qcow2: Add calculate_l2_meta() Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 04/34] qcow2: Split cluster_needs_cow() out of count_cow_clusters() Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 05/34] qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied() Alberto Garcia
2020-06-30 10:38 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 06/34] qcow2: Add get_l2_entry() and set_l2_entry() Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 07/34] qcow2: Document the Extended L2 Entries feature Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 08/34] qcow2: Add dummy has_subclusters() function Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 09/34] qcow2: Add subcluster-related fields to BDRVQcow2State Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 10/34] qcow2: Add offset_to_sc_index() Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 11/34] qcow2: Add offset_into_subcluster() and size_to_subclusters() Alberto Garcia
2020-07-01 12:23 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 12/34] qcow2: Add l2_entry_size() Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 13/34] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap() Alberto Garcia
2020-07-01 12:28 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 14/34] qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type() Alberto Garcia
2020-07-01 12:52 ` Max Reitz
2020-07-01 16:26 ` Alberto Garcia
2020-07-02 9:57 ` Max Reitz
2020-07-02 22:00 ` Alberto Garcia
2020-07-03 7:17 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 15/34] qcow2: Add qcow2_get_subcluster_range_type() Alberto Garcia
2020-07-01 13:37 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 16/34] qcow2: Add qcow2_cluster_is_allocated() Alberto Garcia
2020-07-01 13:55 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 17/34] qcow2: Add cluster type parameter to qcow2_get_host_offset() Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 18/34] qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_* Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 19/34] qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 20/34] qcow2: Add subcluster support to calculate_l2_meta() Alberto Garcia
2020-07-02 11:30 ` Max Reitz
2020-06-28 11:02 ` Alberto Garcia [this message]
2020-07-02 12:46 ` [PATCH v9 21/34] qcow2: Add subcluster support to qcow2_get_host_offset() Max Reitz
2020-07-02 22:04 ` Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 22/34] qcow2: Add subcluster support to zero_in_l2_slice() Alberto Garcia
2020-07-02 12:56 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 23/34] qcow2: Add subcluster support to discard_in_l2_slice() Alberto Garcia
2020-07-02 13:24 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 24/34] qcow2: Add subcluster support to check_refcounts_l2() Alberto Garcia
2020-07-02 13:32 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 25/34] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2() Alberto Garcia
2020-07-02 14:01 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 26/34] qcow2: Clear the L2 bitmap when allocating a compressed cluster Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 27/34] qcow2: Add subcluster support to handle_alloc_space() Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 28/34] qcow2: Add subcluster support to qcow2_co_pwrite_zeroes() Alberto Garcia
2020-07-02 14:28 ` Max Reitz
2020-07-02 22:40 ` Alberto Garcia
2020-07-03 7:18 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 29/34] qcow2: Add subcluster support to qcow2_measure() Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 30/34] qcow2: Add prealloc field to QCowL2Meta Alberto Garcia
2020-07-02 14:50 ` Max Reitz
2020-07-02 14:58 ` Eric Blake
2020-07-02 15:09 ` Max Reitz
2020-07-02 23:05 ` Alberto Garcia
2020-07-03 7:22 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 31/34] qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit Alberto Garcia
2020-07-02 15:13 ` Max Reitz
2020-07-03 12:43 ` Alberto Garcia
2020-06-28 11:02 ` [PATCH v9 32/34] qcow2: Allow preallocation and backing files if extended_l2 is set Alberto Garcia
2020-07-03 7:45 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 33/34] qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters Alberto Garcia
2020-07-03 7:46 ` Max Reitz
2020-06-28 11:02 ` [PATCH v9 34/34] iotests: Add tests for qcow2 images with extended L2 entries Alberto Garcia
2020-07-03 9:49 ` Max Reitz
2020-07-03 13:06 ` Alberto Garcia
2020-07-03 13:47 ` Max Reitz
2020-07-03 15:20 ` Alberto Garcia
2020-07-06 13:57 ` Eric Blake
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