qemu_iovec_concat() is currently a wrapper for qemu_iovec_copy(),
use the former (with extra "0" arg) in a few places where it is used.
Change skip argument of qemu_iovec_copy() from uint64_t to size_t,
since size of qiov itself is size_t, so there's no way to skip larger
sizes. Rename it to soffset, to make it clear that the offset
is applied to src.
Also change the only usage of uint64_t in hw/9pfs/virtio-9p.c, in
v9fs_init_qiov_from_pdu() - all callers of it actually uses size_t
too, not uint64_t.
Semantic change in the meaning of `count' (now renamed to `sbytes')
argument. Initial comment said that src is copied to dst until
_total_ size is less than specified, so it might be interpreted
as maximum size of the _dst_ vector. Actual meaning of if was
that total amount of skipped and copied bytes should not exceed
`count'. Make it just the amount of bytes to _copy_, without
counting skipped bytes. This makes it consistent with other
iovec functions, and also matches actual _usage_ of this function.
Order of argumens is already good:
qemu_iovec_memset(QEMUIOVector *qiov, size_t offset, int c, size_t bytes)
vs:
qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t soffset, size_t
sbytes)
(note soffset is after _src_ not dst, since it applies to src;
for memset it applies to qiov).
Note that in many places where this function is used, the previous
call is qemu_iovec_reset(), which means many callers actually want
copy (replacing dst content), not concat. So we may want to add a
paramere to allow resetting dst in one go.
---
block.c | 4 +-
block/qcow2.c | 6 ++--
block/qed.c | 6 ++--
cutils.c | 56 +++++++++++++++++++-------------------------------
hw/9pfs/virtio-9p.c | 8 +++---
qemu-common.h | 5 +--
6 files changed, 35 insertions(+), 50 deletions(-)
diff --git a/block.c b/block.c
index cbbedfa..3baa182 100644
--- a/block.c
+++ b/block.c
@@ -2959,13 +2959,13 @@ static int multiwrite_merge(BlockDriverState *bs,
BlockRequest *reqs,
// Add the first request to the merged one. If the requests are
// overlapping, drop the last sectors of the first request.
size = (reqs[i].sector - reqs[outidx].sector) << 9;
- qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
+ qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size);
// We should need to add any zeros between the two requests
assert (reqs[i].sector <= oldreq_last);
// Add the second request
- qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
+ qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size);
reqs[outidx].nb_sectors = qiov->size >> 9;
reqs[outidx].qiov = qiov;
diff --git a/block/qcow2.c b/block/qcow2.c
index 668e2e2..1723275 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -445,7 +445,7 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState
*bs, int64_t sector_num,
index_in_cluster = sector_num & (s->cluster_sectors - 1);
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
cur_nr_sectors * 512);
if (!cluster_offset) {
@@ -514,7 +514,7 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState
*bs, int64_t sector_num,
qcow2_encrypt_sectors(s, sector_num, cluster_data,
cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
cur_nr_sectors * 512);
qemu_iovec_from_buffer(&hd_qiov, 0, cluster_data,
512 * cur_nr_sectors);
@@ -596,7 +596,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState
*bs,
assert((cluster_offset & 511) == 0);
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
cur_nr_sectors * 512);
if (s->crypt_method) {
diff --git a/block/qed.c b/block/qed.c
index 6f9325b..a4ef12c 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1133,7 +1133,7 @@ static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len)
acb->cur_nclusters = qed_bytes_to_clusters(s,
qed_offset_into_cluster(s, acb->cur_pos) + len);
- qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
+ qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
if (acb->flags & QED_AIOCB_ZERO) {
/* Skip ahead if the clusters are already zero */
@@ -1179,7 +1179,7 @@ static void qed_aio_write_inplace(QEDAIOCB *acb, uint64_t
offset, size_t len)
/* Calculate the I/O vector */
acb->cur_cluster = offset;
- qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
+ qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
/* Do the actual write */
qed_aio_write_main(acb, 0);
@@ -1249,7 +1249,7 @@ static void qed_aio_read_data(void *opaque, int ret,
goto err;
}
- qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
+ qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
/* Handle zero cluster and backing file reads */
if (ret == QED_CLUSTER_ZERO) {
diff --git a/cutils.c b/cutils.c
index 5353f89..04e51f7 100644
--- a/cutils.c
+++ b/cutils.c
@@ -171,48 +171,34 @@ void qemu_iovec_add(QEMUIOVector *qiov, void *base,
size_t len)
}
/*
- * Copies iovecs from src to the end of dst. It starts copying after skipping
- * the given number of bytes in src and copies until src is completely copied
- * or the total size of the copied iovec reaches size.The size of the last
- * copied iovec is changed in order to fit the specified total size if it isn't
- * a perfect fit already.
+ * Concatenates (partial) iovecs from src to the end of dst.
+ * It starts copying after skipping `soffset' bytes at the
+ * beginning of src and copies `sbytes' bytes from that point.
+ * The size of the last copied iovec is changed in order to fit the
+ * specified total size if it isn't a perfect fit already.
*/
-void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
- size_t size)
+void qemu_iovec_concat(QEMUIOVector *dst,
+ QEMUIOVector *src, size_t soffset, size_t sbytes)
{
int i;
- size_t done;
- void *iov_base;
- uint64_t iov_len;
+ struct iovec *siov = src->iov;
assert(dst->nalloc != -1);
+ assert(src->size >= soffset);
+ assert(src->size - soffset >= sbytes);
- done = 0;
- for (i = 0; (i < src->niov) && (done != size); i++) {
- if (skip >= src->iov[i].iov_len) {
- /* Skip the whole iov */
- skip -= src->iov[i].iov_len;
- continue;
- } else {
- /* Skip only part (or nothing) of the iov */
- iov_base = (uint8_t*) src->iov[i].iov_base + skip;
- iov_len = src->iov[i].iov_len - skip;
- skip = 0;
- }
-
- if (done + iov_len > size) {
- qemu_iovec_add(dst, iov_base, size - done);
- break;
- } else {
- qemu_iovec_add(dst, iov_base, iov_len);
- }
- done += iov_len;
+ /* first skip initial full-sized source elements */
+ for(i = 0; soffset >= siov[i].iov_len; ++i) {
+ soffset -= siov[i].iov_len;
+ }
+ /* skip/copy partial element and copy the rest */
+ while(sbytes) {
+ size_t n = MIN(sbytes, siov[i].iov_len - soffset);
+ qemu_iovec_add(dst, (char*)siov[i].iov_base + soffset, n);
+ sbytes -= n;
+ ++i;
+ soffset = 0;
}
-}
-
-void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
-{
- qemu_iovec_copy(dst, src, 0, size);
}
void qemu_iovec_destroy(QEMUIOVector *qiov)
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index c633fb9..f4a7026 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -1648,7 +1648,7 @@ out:
* with qemu_iovec_destroy().
*/
static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov, V9fsPDU *pdu,
- uint64_t skip, size_t size,
+ size_t skip, size_t size,
bool is_write)
{
QEMUIOVector elem;
@@ -1665,7 +1665,7 @@ static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov,
V9fsPDU *pdu,
qemu_iovec_init_external(&elem, iov, niov);
qemu_iovec_init(qiov, niov);
- qemu_iovec_copy(qiov, &elem, skip, size);
+ qemu_iovec_concat(qiov, &elem, skip, size);
}
static void v9fs_read(void *opaque)
@@ -1715,7 +1715,7 @@ static void v9fs_read(void *opaque)
qemu_iovec_init(&qiov, qiov_full.niov);
do {
qemu_iovec_reset(&qiov);
- qemu_iovec_copy(&qiov, &qiov_full, count, qiov_full.size - count);
+ qemu_iovec_concat(&qiov, &qiov_full, count, qiov_full.size -
count);
if (0) {
print_sg(qiov.iov, qiov.niov);
}
@@ -1970,7 +1970,7 @@ static void v9fs_write(void *opaque)
qemu_iovec_init(&qiov, qiov_full.niov);
do {
qemu_iovec_reset(&qiov);
- qemu_iovec_copy(&qiov, &qiov_full, total, qiov_full.size - total);
+ qemu_iovec_concat(&qiov, &qiov_full, total, qiov_full.size - total);
if (0) {
print_sg(qiov.iov, qiov.niov);
}
diff --git a/qemu-common.h b/qemu-common.h
index 249f70d..e8d1429 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -333,9 +333,8 @@ typedef struct QEMUIOVector {
void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint);
void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov);
void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len);
-void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
- size_t size);
-void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size);
+void qemu_iovec_concat(QEMUIOVector *dst,
+ QEMUIOVector *src, size_t soffset, size_t sbytes);
void qemu_iovec_destroy(QEMUIOVector *qiov);
void qemu_iovec_reset(QEMUIOVector *qiov);
void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf);
--
1.7.9.1
