diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/qed.c | 38 | ||||
| -rw-r--r-- | block/qed.h | 1 |
2 files changed, 31 insertions, 8 deletions
diff --git a/block/qed.c b/block/qed.c index b69374b..cd4872b 100644 --- a/block/qed.c +++ b/block/qed.c @@ -761,17 +761,19 @@ static BDRVQEDState *acb_to_s(QEDAIOCB *acb) /** * Read from the backing file or zero-fill if no backing file * - * @s: QED state - * @pos: Byte position in device - * @qiov: Destination I/O vector - * @cb: Completion function - * @opaque: User data for completion function + * @s: QED state + * @pos: Byte position in device + * @qiov: Destination I/O vector + * @backing_qiov: Possibly shortened copy of qiov, to be allocated here + * @cb: Completion function + * @opaque: User data for completion function * * This function reads qiov->size bytes starting at pos from the backing file. * If there is no backing file then zeroes are read. */ static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos, QEMUIOVector *qiov, + QEMUIOVector **backing_qiov, BlockDriverCompletionFunc *cb, void *opaque) { uint64_t backing_length = 0; @@ -804,15 +806,21 @@ static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos, /* If the read straddles the end of the backing file, shorten it */ size = MIN((uint64_t)backing_length - pos, qiov->size); + assert(*backing_qiov == NULL); + *backing_qiov = g_new(QEMUIOVector, 1); + qemu_iovec_init(*backing_qiov, qiov->niov); + qemu_iovec_concat(*backing_qiov, qiov, 0, size); + BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE, - qiov, size / BDRV_SECTOR_SIZE, cb, opaque); + *backing_qiov, size / BDRV_SECTOR_SIZE, cb, opaque); } typedef struct { GenericCB gencb; BDRVQEDState *s; QEMUIOVector qiov; + QEMUIOVector *backing_qiov; struct iovec iov; uint64_t offset; } CopyFromBackingFileCB; @@ -829,6 +837,12 @@ static void qed_copy_from_backing_file_write(void *opaque, int ret) CopyFromBackingFileCB *copy_cb = opaque; BDRVQEDState *s = copy_cb->s; + if (copy_cb->backing_qiov) { + qemu_iovec_destroy(copy_cb->backing_qiov); + g_free(copy_cb->backing_qiov); + copy_cb->backing_qiov = NULL; + } + if (ret) { qed_copy_from_backing_file_cb(copy_cb, ret); return; @@ -866,11 +880,12 @@ static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos, copy_cb = gencb_alloc(sizeof(*copy_cb), cb, opaque); copy_cb->s = s; copy_cb->offset = offset; + copy_cb->backing_qiov = NULL; copy_cb->iov.iov_base = qemu_blockalign(s->bs, len); copy_cb->iov.iov_len = len; qemu_iovec_init_external(©_cb->qiov, ©_cb->iov, 1); - qed_read_backing_file(s, pos, ©_cb->qiov, + qed_read_backing_file(s, pos, ©_cb->qiov, ©_cb->backing_qiov, qed_copy_from_backing_file_write, copy_cb); } @@ -1313,7 +1328,7 @@ static void qed_aio_read_data(void *opaque, int ret, return; } else if (ret != QED_CLUSTER_FOUND) { qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, - qed_aio_next_io, acb); + &acb->backing_qiov, qed_aio_next_io, acb); return; } @@ -1339,6 +1354,12 @@ static void qed_aio_next_io(void *opaque, int ret) trace_qed_aio_next_io(s, acb, ret, acb->cur_pos + acb->cur_qiov.size); + if (acb->backing_qiov) { + qemu_iovec_destroy(acb->backing_qiov); + g_free(acb->backing_qiov); + acb->backing_qiov = NULL; + } + /* Handle I/O error */ if (ret) { qed_aio_complete(acb, ret); @@ -1378,6 +1399,7 @@ static BlockDriverAIOCB *qed_aio_setup(BlockDriverState *bs, acb->qiov_offset = 0; acb->cur_pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE; acb->end_pos = acb->cur_pos + nb_sectors * BDRV_SECTOR_SIZE; + acb->backing_qiov = NULL; acb->request.l2_table = NULL; qemu_iovec_init(&acb->cur_qiov, qiov->niov); diff --git a/block/qed.h b/block/qed.h index b024751..2b0e724 100644 --- a/block/qed.h +++ b/block/qed.h @@ -142,6 +142,7 @@ typedef struct QEDAIOCB { /* Current cluster scatter-gather list */ QEMUIOVector cur_qiov; + QEMUIOVector *backing_qiov; uint64_t cur_pos; /* position on block device, in bytes */ uint64_t cur_cluster; /* cluster offset in image file */ unsigned int cur_nclusters; /* number of clusters being accessed */ |
