From 68066d2b824a88a45b3263dd1ceb18307c92581f Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Sat, 15 Feb 2014 16:03:47 +0100 Subject: [PATCH 2/5] qcow2: remove n_start and n_end of qcow2_alloc_cluster_offset() RH-Author: Max Reitz Message-id: <1392480230-24011-2-git-send-email-mreitz@redhat.com> Patchwork-id: 57292 O-Subject: [RHEL-7.0 qemu-kvm PATCH 1/4] qcow2: remove n_start and n_end of qcow2_alloc_cluster_offset() Bugzilla: 1049176 RH-Acked-by: Kevin Wolf RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Fam Zheng From: Hu Tao BZ: 1049176 BZ: 1055848 n_start can be actually calculated from offset. The number of sectors to be allocated(n_end - n_start) can be passed in in num. By removing n_start and n_end, we can save two parameters. The side effect is there is a bug in qcow2.c:preallocate() that passes incorrect n_start to qcow2_alloc_cluster_offset() is fixed. The bug can be triggerred by a larger cluster size than the default value(65536), for example: ./qemu-img create -f qcow2 \ -o 'cluster_size=131072,preallocation=metadata' file.img 4G Signed-off-by: Hu Tao Reviewed-by: Max Reitz Reviewed-by: Benoit Canet Signed-off-by: Kevin Wolf (cherry picked from commit 16f0587e0a5da5b1ad76cb7c3739491bc042201c) Signed-off-by: Max Reitz --- block/qcow2-cluster.c | 14 ++++++-------- block/qcow2.c | 13 +++++++------ block/qcow2.h | 2 +- trace-events | 2 +- 4 files changed, 15 insertions(+), 16 deletions(-) Signed-off-by: Miroslav Rezanina --- block/qcow2-cluster.c | 14 ++++++-------- block/qcow2.c | 13 +++++++------ block/qcow2.h | 2 +- trace-events | 2 +- 4 files changed, 15 insertions(+), 16 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 79c3ae0..862df0f 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1173,7 +1173,7 @@ fail: * Return 0 on success and -errno in error cases */ int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, - int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m) + int *num, uint64_t *host_offset, QCowL2Meta **m) { BDRVQcowState *s = bs->opaque; uint64_t start, remaining; @@ -1181,15 +1181,13 @@ int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, uint64_t cur_bytes; int ret; - trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset, - n_start, n_end); + trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset, *num); - assert(n_start * BDRV_SECTOR_SIZE == offset_into_cluster(s, offset)); - offset = start_of_cluster(s, offset); + assert((offset & ~BDRV_SECTOR_MASK) == 0); again: - start = offset + (n_start << BDRV_SECTOR_BITS); - remaining = (n_end - n_start) << BDRV_SECTOR_BITS; + start = offset; + remaining = *num << BDRV_SECTOR_BITS; cluster_offset = 0; *host_offset = 0; cur_bytes = 0; @@ -1275,7 +1273,7 @@ again: } } - *num = (n_end - n_start) - (remaining >> BDRV_SECTOR_BITS); + *num -= remaining >> BDRV_SECTOR_BITS; assert(*num > 0); assert(*host_offset != 0); diff --git a/block/qcow2.c b/block/qcow2.c index 25a5b5e..fe950b4 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1000,7 +1000,6 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, { BDRVQcowState *s = bs->opaque; int index_in_cluster; - int n_end; int ret; int cur_nr_sectors; /* number of sectors in current iteration */ uint64_t cluster_offset; @@ -1024,14 +1023,16 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, trace_qcow2_writev_start_part(qemu_coroutine_self()); index_in_cluster = sector_num & (s->cluster_sectors - 1); - n_end = index_in_cluster + remaining_sectors; + cur_nr_sectors = remaining_sectors; if (s->crypt_method && - n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) { - n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; + cur_nr_sectors > + QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster) { + cur_nr_sectors = + QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster; } ret = qcow2_alloc_cluster_offset(bs, sector_num << 9, - index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, &l2meta); + &cur_nr_sectors, &cluster_offset, &l2meta); if (ret < 0) { goto fail; } @@ -1408,7 +1409,7 @@ static int preallocate(BlockDriverState *bs) while (nb_sectors) { num = MIN(nb_sectors, INT_MAX >> 9); - ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, + ret = qcow2_alloc_cluster_offset(bs, offset, &num, &host_offset, &meta); if (ret < 0) { return ret; diff --git a/block/qcow2.h b/block/qcow2.h index 9749f03..4a653c5 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -463,7 +463,7 @@ void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num, int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, int *num, uint64_t *cluster_offset); int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, - int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m); + int *num, uint64_t *host_offset, QCowL2Meta **m); uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, uint64_t offset, int compressed_size); diff --git a/trace-events b/trace-events index 5d86cf3..b9144b2 100644 --- a/trace-events +++ b/trace-events @@ -485,7 +485,7 @@ qcow2_writev_done_part(void *co, int cur_nr_sectors) "co %p cur_nr_sectors %d" qcow2_writev_data(void *co, uint64_t offset) "co %p offset %" PRIx64 # block/qcow2-cluster.c -qcow2_alloc_clusters_offset(void *co, uint64_t offset, int n_start, int n_end) "co %p offet %" PRIx64 " n_start %d n_end %d" +qcow2_alloc_clusters_offset(void *co, uint64_t offset, int num) "co %p offet %" PRIx64 " num %d" qcow2_handle_copied(void *co, uint64_t guest_offset, uint64_t host_offset, uint64_t bytes) "co %p guest_offet %" PRIx64 " host_offset %" PRIx64 " bytes %" PRIx64 qcow2_handle_alloc(void *co, uint64_t guest_offset, uint64_t host_offset, uint64_t bytes) "co %p guest_offet %" PRIx64 " host_offset %" PRIx64 " bytes %" PRIx64 qcow2_do_alloc_clusters_offset(void *co, uint64_t guest_offset, uint64_t host_offset, int nb_clusters) "co %p guest_offet %" PRIx64 " host_offset %" PRIx64 " nb_clusters %d" -- 1.7.1