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| author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2021-09-14 15:24:46 +0300 |
|---|---|---|
| committer | Hanna Reitz <hreitz@redhat.com> | 2021-09-15 18:42:38 +0200 |
| commit | 9a3978a46bc12e0c49b7114983103b07d90cfa1c (patch) | |
| tree | 6547f2bdf64e1180f9b4a52154191c66ec30098e /block | |
| parent | 786c22d9c2c890f7c7fcd2600571a2ef429d65db (diff) | |
| download | qemu-9a3978a46bc12e0c49b7114983103b07d90cfa1c.zip qemu-9a3978a46bc12e0c49b7114983103b07d90cfa1c.tar.gz qemu-9a3978a46bc12e0c49b7114983103b07d90cfa1c.tar.bz2 | |
qcow2: compressed read: simplify cluster descriptor passing
Let's pass the whole L2 entry and not bother with
L2E_COMPRESSED_OFFSET_SIZE_MASK.
It also helps further refactoring that adds generic
qcow2_parse_compressed_l2_entry() helper.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20210914122454.141075-3-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/qcow2-cluster.c | 5 | ||||
| -rw-r--r-- | block/qcow2.c | 12 | ||||
| -rw-r--r-- | block/qcow2.h | 1 |
3 files changed, 9 insertions, 9 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index c1c43a8..3d53657 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -556,8 +556,7 @@ static int coroutine_fn do_perform_cow_write(BlockDriverState *bs, * offset needs to be aligned to a cluster boundary. * * If the cluster is unallocated then *host_offset will be 0. - * If the cluster is compressed then *host_offset will contain the - * complete compressed cluster descriptor. + * If the cluster is compressed then *host_offset will contain the l2 entry. * * On entry, *bytes is the maximum number of contiguous bytes starting at * offset that we are interested in. @@ -660,7 +659,7 @@ int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset, ret = -EIO; goto fail; } - *host_offset = l2_entry & L2E_COMPRESSED_OFFSET_SIZE_MASK; + *host_offset = l2_entry; break; case QCOW2_SUBCLUSTER_ZERO_PLAIN: case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: diff --git a/block/qcow2.c b/block/qcow2.c index 9f1b646..e5d8ab6 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -74,7 +74,7 @@ typedef struct { static int coroutine_fn qcow2_co_preadv_compressed(BlockDriverState *bs, - uint64_t cluster_descriptor, + uint64_t l2_entry, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, @@ -2205,7 +2205,7 @@ typedef struct Qcow2AioTask { BlockDriverState *bs; QCow2SubclusterType subcluster_type; /* only for read */ - uint64_t host_offset; /* or full descriptor in compressed clusters */ + uint64_t host_offset; /* or l2_entry for compressed read */ uint64_t offset; uint64_t bytes; QEMUIOVector *qiov; @@ -4693,7 +4693,7 @@ qcow2_co_pwritev_compressed_part(BlockDriverState *bs, static int coroutine_fn qcow2_co_preadv_compressed(BlockDriverState *bs, - uint64_t cluster_descriptor, + uint64_t l2_entry, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, @@ -4705,8 +4705,10 @@ qcow2_co_preadv_compressed(BlockDriverState *bs, uint8_t *buf, *out_buf; int offset_in_cluster = offset_into_cluster(s, offset); - coffset = cluster_descriptor & s->cluster_offset_mask; - nb_csectors = ((cluster_descriptor >> s->csize_shift) & s->csize_mask) + 1; + assert(qcow2_get_cluster_type(bs, l2_entry) == QCOW2_CLUSTER_COMPRESSED); + + coffset = l2_entry & s->cluster_offset_mask; + nb_csectors = ((l2_entry >> s->csize_shift) & s->csize_mask) + 1; csize = nb_csectors * QCOW2_COMPRESSED_SECTOR_SIZE - (coffset & ~QCOW2_COMPRESSED_SECTOR_MASK); diff --git a/block/qcow2.h b/block/qcow2.h index 0fe5f74..42a0058 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -588,7 +588,6 @@ typedef enum QCow2MetadataOverlap { #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL -#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL |