This patch combines two functions into one, simplifies the
implementation and adds some assert()s into place.
Signed-off-by: Michael Tokarev <m...@tls.msk.ru>
---
block/qcow2.c | 4 +-
block/qed.c | 4 +-
cutils.c | 54 +++++++++++++++------------------------------------
linux-aio.c | 2 +-
posix-aio-compat.c | 2 +-
qemu-common.h | 4 +--
6 files changed, 23 insertions(+), 47 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index eb5ea48..b39bdcc 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -406,7 +406,7 @@ int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector
*qiov,
else
n1 = bs->total_sectors - sector_num;
- qemu_iovec_memset_skip(qiov, 0, 512 * (nb_sectors - n1), 512 * n1);
+ qemu_iovec_memset(qiov, 0, 512 * (nb_sectors - n1), 512 * n1);
return n1;
}
@@ -466,7 +466,7 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState
*bs, int64_t sector_num,
}
} else {
/* Note: in this case, no need to wait */
- qemu_iovec_memset(&hd_qiov, 0, 512 * cur_nr_sectors);
+ qemu_iovec_memset(&hd_qiov, 0, 512 * cur_nr_sectors, 0);
}
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
/* add AIO support for compressed blocks ? */
diff --git a/block/qed.c b/block/qed.c
index a041d31..427cf13 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -738,7 +738,7 @@ static void qed_read_backing_file(BDRVQEDState *s, uint64_t
pos,
/* Zero all sectors if reading beyond the end of the backing file */
if (pos >= backing_length ||
pos + qiov->size > backing_length) {
- qemu_iovec_memset(qiov, 0, qiov->size);
+ qemu_iovec_memset(qiov, 0, qiov->size, 0);
}
/* Complete now if there are no backing file sectors to read */
@@ -1253,7 +1253,7 @@ static void qed_aio_read_data(void *opaque, int ret,
/* Handle zero cluster and backing file reads */
if (ret == QED_CLUSTER_ZERO) {
- qemu_iovec_memset(&acb->cur_qiov, 0, acb->cur_qiov.size);
+ qemu_iovec_memset(&acb->cur_qiov, 0, acb->cur_qiov.size, 0);
qed_aio_next_io(acb, 0);
return;
} else if (ret != QED_CLUSTER_FOUND) {
diff --git a/cutils.c b/cutils.c
index af308cd..27687c8 100644
--- a/cutils.c
+++ b/cutils.c
@@ -260,46 +260,24 @@ void qemu_iovec_from_buffer(QEMUIOVector *qiov, const
void *buf, size_t count)
}
}
-void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t count)
+void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t bytes, size_t offset)
{
- size_t n;
- int i;
-
- for (i = 0; i < qiov->niov && count; ++i) {
- n = MIN(count, qiov->iov[i].iov_len);
- memset(qiov->iov[i].iov_base, c, n);
- count -= n;
+ struct iovec *iov = qiov->iov;
+ unsigned i;
+ assert(qiov->size >= offset);
+ assert(qiov->size - offset >= bytes);
+
+ /* first skip initial full-sized elements */
+ for(i = 0; offset >= iov[i].iov_len; ++i) {
+ offset -= iov[i].iov_len;
}
-}
-
-void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count,
- size_t skip)
-{
- int i;
- size_t done;
- void *iov_base;
- uint64_t iov_len;
-
- done = 0;
- for (i = 0; (i < qiov->niov) && (done != count); i++) {
- if (skip >= qiov->iov[i].iov_len) {
- /* Skip the whole iov */
- skip -= qiov->iov[i].iov_len;
- continue;
- } else {
- /* Skip only part (or nothing) of the iov */
- iov_base = (uint8_t*) qiov->iov[i].iov_base + skip;
- iov_len = qiov->iov[i].iov_len - skip;
- skip = 0;
- }
-
- if (done + iov_len > count) {
- memset(iov_base, c, count - done);
- break;
- } else {
- memset(iov_base, c, iov_len);
- }
- done += iov_len;
+ /* skip/memset partial element and memset the rest */
+ while(bytes) {
+ size_t n = MIN(bytes, iov[i].iov_len - offset);
+ memset(iov[i].iov_base + offset, c, n);
+ bytes -= n;
+ ++i;
+ offset = 0;
}
}
diff --git a/linux-aio.c b/linux-aio.c
index d2fc2e7..303f410 100644
--- a/linux-aio.c
+++ b/linux-aio.c
@@ -64,7 +64,7 @@ static void qemu_laio_process_completion(struct
qemu_laio_state *s,
} else if (ret >= 0) {
/* Short reads mean EOF, pad with zeros. */
if (laiocb->is_read) {
- qemu_iovec_memset_skip(laiocb->qiov, 0,
+ qemu_iovec_memset(laiocb->qiov, 0,
laiocb->qiov->size - ret, ret);
} else {
ret = -EINVAL;
diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index d311d13..84aafed 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -355,7 +355,7 @@ static void *aio_thread(void *unused)
qemu_iovec_init_external(&qiov, aiocb->aio_iov,
aiocb->aio_niov);
- qemu_iovec_memset_skip(&qiov, 0, aiocb->aio_nbytes - ret, ret);
+ qemu_iovec_memset(&qiov, 0, aiocb->aio_nbytes - ret, ret);
ret = aiocb->aio_nbytes;
}
diff --git a/qemu-common.h b/qemu-common.h
index dbfce6f..b7e426e 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -340,9 +340,7 @@ void qemu_iovec_destroy(QEMUIOVector *qiov);
void qemu_iovec_reset(QEMUIOVector *qiov);
void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf);
void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void *buf, size_t count);
-void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t count);
-void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count,
- size_t skip);
+void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t bytes, size_t offset);
bool buffer_is_zero(const void *buf, size_t len);
--
1.7.9.1
