* [Qemu-devel] [PULL 01/12] util/iov: introduce qemu_iovec_init_extended
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-09-09 17:39 ` Peter Maydell
2019-08-27 20:16 ` [Qemu-devel] [PULL 02/12] util/iov: improve qemu_iovec_is_zero Stefan Hajnoczi
` (11 subsequent siblings)
12 siblings, 1 reply; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Introduce new initialization API, to create requests with padding. Will
be used in the following patch. New API uses qemu_iovec_init_buf if
resulting io vector has only one element, to avoid extra allocations.
So, we need to update qemu_iovec_destroy to support destroying such
QIOVs.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-2-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-2-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/qemu/iov.h | 7 +++
util/iov.c | 112 +++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 114 insertions(+), 5 deletions(-)
diff --git a/include/qemu/iov.h b/include/qemu/iov.h
index 48b45987b7..f3787a0cf7 100644
--- a/include/qemu/iov.h
+++ b/include/qemu/iov.h
@@ -199,6 +199,13 @@ static inline void *qemu_iovec_buf(QEMUIOVector *qiov)
void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint);
void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov);
+void qemu_iovec_init_extended(
+ QEMUIOVector *qiov,
+ void *head_buf, size_t head_len,
+ QEMUIOVector *mid_qiov, size_t mid_offset, size_t mid_len,
+ void *tail_buf, size_t tail_len);
+void qemu_iovec_init_slice(QEMUIOVector *qiov, QEMUIOVector *source,
+ size_t offset, size_t len);
void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len);
void qemu_iovec_concat(QEMUIOVector *dst,
QEMUIOVector *src, size_t soffset, size_t sbytes);
diff --git a/util/iov.c b/util/iov.c
index 74e6ca8ed7..366ff9cdd1 100644
--- a/util/iov.c
+++ b/util/iov.c
@@ -353,6 +353,103 @@ void qemu_iovec_concat(QEMUIOVector *dst,
qemu_iovec_concat_iov(dst, src->iov, src->niov, soffset, sbytes);
}
+/*
+ * qiov_find_iov
+ *
+ * Return pointer to iovec structure, where byte at @offset in original vector
+ * @iov exactly is.
+ * Set @remaining_offset to be offset inside that iovec to the same byte.
+ */
+static struct iovec *iov_skip_offset(struct iovec *iov, size_t offset,
+ size_t *remaining_offset)
+{
+ while (offset > 0 && offset >= iov->iov_len) {
+ offset -= iov->iov_len;
+ iov++;
+ }
+ *remaining_offset = offset;
+
+ return iov;
+}
+
+/*
+ * qiov_slice
+ *
+ * Find subarray of iovec's, containing requested range. @head would
+ * be offset in first iov (returned by the function), @tail would be
+ * count of extra bytes in last iovec (returned iov + @niov - 1).
+ */
+static struct iovec *qiov_slice(QEMUIOVector *qiov,
+ size_t offset, size_t len,
+ size_t *head, size_t *tail, int *niov)
+{
+ struct iovec *iov, *end_iov;
+
+ assert(offset + len <= qiov->size);
+
+ iov = iov_skip_offset(qiov->iov, offset, head);
+ end_iov = iov_skip_offset(iov, *head + len, tail);
+
+ if (*tail > 0) {
+ assert(*tail < end_iov->iov_len);
+ *tail = end_iov->iov_len - *tail;
+ end_iov++;
+ }
+
+ *niov = end_iov - iov;
+
+ return iov;
+}
+
+/*
+ * Compile new iovec, combining @head_buf buffer, sub-qiov of @mid_qiov,
+ * and @tail_buf buffer into new qiov.
+ */
+void qemu_iovec_init_extended(
+ QEMUIOVector *qiov,
+ void *head_buf, size_t head_len,
+ QEMUIOVector *mid_qiov, size_t mid_offset, size_t mid_len,
+ void *tail_buf, size_t tail_len)
+{
+ size_t mid_head, mid_tail;
+ int total_niov, mid_niov = 0;
+ struct iovec *p, *mid_iov;
+
+ if (mid_len) {
+ mid_iov = qiov_slice(mid_qiov, mid_offset, mid_len,
+ &mid_head, &mid_tail, &mid_niov);
+ }
+
+ total_niov = !!head_len + mid_niov + !!tail_len;
+ if (total_niov == 1) {
+ qemu_iovec_init_buf(qiov, NULL, 0);
+ p = &qiov->local_iov;
+ } else {
+ qiov->niov = qiov->nalloc = total_niov;
+ qiov->size = head_len + mid_len + tail_len;
+ p = qiov->iov = g_new(struct iovec, qiov->niov);
+ }
+
+ if (head_len) {
+ p->iov_base = head_buf;
+ p->iov_len = head_len;
+ p++;
+ }
+
+ if (mid_len) {
+ memcpy(p, mid_iov, mid_niov * sizeof(*p));
+ p[0].iov_base = (uint8_t *)p[0].iov_base + mid_head;
+ p[0].iov_len -= mid_head;
+ p[mid_niov - 1].iov_len -= mid_tail;
+ p += mid_niov;
+ }
+
+ if (tail_len) {
+ p->iov_base = tail_buf;
+ p->iov_len = tail_len;
+ }
+}
+
/*
* Check if the contents of the iovecs are all zero
*/
@@ -374,14 +471,19 @@ bool qemu_iovec_is_zero(QEMUIOVector *qiov)
return true;
}
+void qemu_iovec_init_slice(QEMUIOVector *qiov, QEMUIOVector *source,
+ size_t offset, size_t len)
+{
+ qemu_iovec_init_extended(qiov, NULL, 0, source, offset, len, NULL, 0);
+}
+
void qemu_iovec_destroy(QEMUIOVector *qiov)
{
- assert(qiov->nalloc != -1);
+ if (qiov->nalloc != -1) {
+ g_free(qiov->iov);
+ }
- qemu_iovec_reset(qiov);
- g_free(qiov->iov);
- qiov->nalloc = 0;
- qiov->iov = NULL;
+ memset(qiov, 0, sizeof(*qiov));
}
void qemu_iovec_reset(QEMUIOVector *qiov)
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [Qemu-devel] [PULL 01/12] util/iov: introduce qemu_iovec_init_extended
2019-08-27 20:16 ` [Qemu-devel] [PULL 01/12] util/iov: introduce qemu_iovec_init_extended Stefan Hajnoczi
@ 2019-09-09 17:39 ` Peter Maydell
2019-09-10 9:03 ` Vladimir Sementsov-Ogievskiy
0 siblings, 1 reply; 16+ messages in thread
From: Peter Maydell @ 2019-09-09 17:39 UTC (permalink / raw)
To: Stefan Hajnoczi
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, Qemu-block,
QEMU Developers, Max Reitz, John Snow
On Tue, 27 Aug 2019 at 21:16, Stefan Hajnoczi <stefanha@redhat.com> wrote:
>
> From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>
> Introduce new initialization API, to create requests with padding. Will
> be used in the following patch. New API uses qemu_iovec_init_buf if
> resulting io vector has only one element, to avoid extra allocations.
> So, we need to update qemu_iovec_destroy to support destroying such
> QIOVs.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
> Message-id: 20190604161514.262241-2-vsementsov@virtuozzo.com
> Message-Id: <20190604161514.262241-2-vsementsov@virtuozzo.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Hi -- Coverity thinks this new function could have an
out-of-bounds read (CID 1405302):
> +/*
> + * Compile new iovec, combining @head_buf buffer, sub-qiov of @mid_qiov,
> + * and @tail_buf buffer into new qiov.
> + */
> +void qemu_iovec_init_extended(
> + QEMUIOVector *qiov,
> + void *head_buf, size_t head_len,
> + QEMUIOVector *mid_qiov, size_t mid_offset, size_t mid_len,
> + void *tail_buf, size_t tail_len)
> +{
> + size_t mid_head, mid_tail;
> + int total_niov, mid_niov = 0;
> + struct iovec *p, *mid_iov;
> +
> + if (mid_len) {
> + mid_iov = qiov_slice(mid_qiov, mid_offset, mid_len,
> + &mid_head, &mid_tail, &mid_niov);
> + }
> +
> + total_niov = !!head_len + mid_niov + !!tail_len;
> + if (total_niov == 1) {
> + qemu_iovec_init_buf(qiov, NULL, 0);
> + p = &qiov->local_iov;
> + } else {
> + qiov->niov = qiov->nalloc = total_niov;
> + qiov->size = head_len + mid_len + tail_len;
> + p = qiov->iov = g_new(struct iovec, qiov->niov);
> + }
> +
> + if (head_len) {
> + p->iov_base = head_buf;
> + p->iov_len = head_len;
> + p++;
> + }
> +
> + if (mid_len) {
> + memcpy(p, mid_iov, mid_niov * sizeof(*p));
> + p[0].iov_base = (uint8_t *)p[0].iov_base + mid_head;
> + p[0].iov_len -= mid_head;
> + p[mid_niov - 1].iov_len -= mid_tail;
> + p += mid_niov;
> + }
> +
> + if (tail_len) {
> + p->iov_base = tail_buf;
> + p->iov_len = tail_len;
> + }
> +}
but I'm not familiar enough with the code to be able to tell
if it's correct or if it's just getting confused. Could
somebody have a look? (It's possible it's getting confused
because the calculation of 'total_niov' uses 'mid_niov',
but the condition guarding the code that fills in that part
of the vector is 'mid_len', so it thinks it can take the
"total_niov == 1" codepath and also the "head_len == true"
and "mid_len != 0" paths; in which case using "if (mid_niov)"
instead might make it happier.)
thanks
-- PMM
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [Qemu-devel] [PULL 01/12] util/iov: introduce qemu_iovec_init_extended
2019-09-09 17:39 ` Peter Maydell
@ 2019-09-10 9:03 ` Vladimir Sementsov-Ogievskiy
0 siblings, 0 replies; 16+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2019-09-10 9:03 UTC (permalink / raw)
To: Peter Maydell, Stefan Hajnoczi
Cc: Fam Zheng, Kevin Wolf, Qemu-block, QEMU Developers, Max Reitz, John Snow
09.09.2019 20:39, Peter Maydell wrote:
> On Tue, 27 Aug 2019 at 21:16, Stefan Hajnoczi <stefanha@redhat.com> wrote:
>>
>> From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>>
>> Introduce new initialization API, to create requests with padding. Will
>> be used in the following patch. New API uses qemu_iovec_init_buf if
>> resulting io vector has only one element, to avoid extra allocations.
>> So, we need to update qemu_iovec_destroy to support destroying such
>> QIOVs.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
>> Message-id: 20190604161514.262241-2-vsementsov@virtuozzo.com
>> Message-Id: <20190604161514.262241-2-vsementsov@virtuozzo.com>
>> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
>
> Hi -- Coverity thinks this new function could have an
> out-of-bounds read (CID 1405302):
>
>> +/*
>> + * Compile new iovec, combining @head_buf buffer, sub-qiov of @mid_qiov,
>> + * and @tail_buf buffer into new qiov.
>> + */
>> +void qemu_iovec_init_extended(
>> + QEMUIOVector *qiov,
>> + void *head_buf, size_t head_len,
>> + QEMUIOVector *mid_qiov, size_t mid_offset, size_t mid_len,
>> + void *tail_buf, size_t tail_len)
>> +{
>> + size_t mid_head, mid_tail;
>> + int total_niov, mid_niov = 0;
>> + struct iovec *p, *mid_iov;
>> +
>> + if (mid_len) {
>> + mid_iov = qiov_slice(mid_qiov, mid_offset, mid_len,
>> + &mid_head, &mid_tail, &mid_niov);
>> + }
>> +
>> + total_niov = !!head_len + mid_niov + !!tail_len;
>> + if (total_niov == 1) {
>> + qemu_iovec_init_buf(qiov, NULL, 0);
>> + p = &qiov->local_iov;
>> + } else {
>> + qiov->niov = qiov->nalloc = total_niov;
>> + qiov->size = head_len + mid_len + tail_len;
>> + p = qiov->iov = g_new(struct iovec, qiov->niov);
>> + }
>> +
>> + if (head_len) {
>> + p->iov_base = head_buf;
>> + p->iov_len = head_len;
>> + p++;
>> + }
>> +
>> + if (mid_len) {
>> + memcpy(p, mid_iov, mid_niov * sizeof(*p));
>> + p[0].iov_base = (uint8_t *)p[0].iov_base + mid_head;
>> + p[0].iov_len -= mid_head;
>> + p[mid_niov - 1].iov_len -= mid_tail;
>> + p += mid_niov;
>> + }
>> +
>> + if (tail_len) {
>> + p->iov_base = tail_buf;
>> + p->iov_len = tail_len;
>> + }
>> +}
>
> but I'm not familiar enough with the code to be able to tell
> if it's correct or if it's just getting confused. Could
> somebody have a look? (It's possible it's getting confused
> because the calculation of 'total_niov' uses 'mid_niov',
> but the condition guarding the code that fills in that part
> of the vector is 'mid_len', so it thinks it can take the
> "total_niov == 1" codepath and also the "head_len == true"
> and "mid_len != 0" paths; in which case using "if (mid_niov)"
> instead might make it happier.)
>
I'm afraid, I don't have better assumption. Let's try.
--
Best regards,
Vladimir
^ permalink raw reply [flat|nested] 16+ messages in thread
* [Qemu-devel] [PULL 02/12] util/iov: improve qemu_iovec_is_zero
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 01/12] util/iov: introduce qemu_iovec_init_extended Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 03/12] block/io: refactor padding Stefan Hajnoczi
` (10 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
We'll need to check a part of qiov soon, so implement it now.
Optimization with align down to 4 * sizeof(long) is dropped due to:
1. It is strange: it aligns length of the buffer, but where is a
guarantee that buffer pointer is aligned itself?
2. buffer_is_zero() is a better place for optimizations and it has
them.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-3-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-3-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/qemu/iov.h | 2 +-
block/io.c | 2 +-
util/iov.c | 31 +++++++++++++++++++------------
3 files changed, 21 insertions(+), 14 deletions(-)
diff --git a/include/qemu/iov.h b/include/qemu/iov.h
index f3787a0cf7..29957c8a72 100644
--- a/include/qemu/iov.h
+++ b/include/qemu/iov.h
@@ -212,7 +212,7 @@ void qemu_iovec_concat(QEMUIOVector *dst,
size_t qemu_iovec_concat_iov(QEMUIOVector *dst,
struct iovec *src_iov, unsigned int src_cnt,
size_t soffset, size_t sbytes);
-bool qemu_iovec_is_zero(QEMUIOVector *qiov);
+bool qemu_iovec_is_zero(QEMUIOVector *qiov, size_t qiov_offeset, size_t bytes);
void qemu_iovec_destroy(QEMUIOVector *qiov);
void qemu_iovec_reset(QEMUIOVector *qiov);
size_t qemu_iovec_to_buf(QEMUIOVector *qiov, size_t offset,
diff --git a/block/io.c b/block/io.c
index 56bbf195bb..f656fb2dce 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1722,7 +1722,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
!(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_pwrite_zeroes &&
- qemu_iovec_is_zero(qiov)) {
+ qemu_iovec_is_zero(qiov, 0, qiov->size)) {
flags |= BDRV_REQ_ZERO_WRITE;
if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
flags |= BDRV_REQ_MAY_UNMAP;
diff --git a/util/iov.c b/util/iov.c
index 366ff9cdd1..9ac0261853 100644
--- a/util/iov.c
+++ b/util/iov.c
@@ -451,23 +451,30 @@ void qemu_iovec_init_extended(
}
/*
- * Check if the contents of the iovecs are all zero
+ * Check if the contents of subrange of qiov data is all zeroes.
*/
-bool qemu_iovec_is_zero(QEMUIOVector *qiov)
+bool qemu_iovec_is_zero(QEMUIOVector *qiov, size_t offset, size_t bytes)
{
- int i;
- for (i = 0; i < qiov->niov; i++) {
- size_t offs = QEMU_ALIGN_DOWN(qiov->iov[i].iov_len, 4 * sizeof(long));
- uint8_t *ptr = qiov->iov[i].iov_base;
- if (offs && !buffer_is_zero(qiov->iov[i].iov_base, offs)) {
+ struct iovec *iov;
+ size_t current_offset;
+
+ assert(offset + bytes <= qiov->size);
+
+ iov = iov_skip_offset(qiov->iov, offset, ¤t_offset);
+
+ while (bytes) {
+ uint8_t *base = (uint8_t *)iov->iov_base + current_offset;
+ size_t len = MIN(iov->iov_len - current_offset, bytes);
+
+ if (!buffer_is_zero(base, len)) {
return false;
}
- for (; offs < qiov->iov[i].iov_len; offs++) {
- if (ptr[offs]) {
- return false;
- }
- }
+
+ current_offset = 0;
+ bytes -= len;
+ iov++;
}
+
return true;
}
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 03/12] block/io: refactor padding
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 01/12] util/iov: introduce qemu_iovec_init_extended Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 02/12] util/iov: improve qemu_iovec_is_zero Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 04/12] block: define .*_part io handlers in BlockDriver Stefan Hajnoczi
` (9 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
We have similar padding code in bdrv_co_pwritev,
bdrv_co_do_pwrite_zeroes and bdrv_co_preadv. Let's combine and unify
it.
[Squashed in Vladimir's qemu-iotests 077 fix
--Stefan]
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-4-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-4-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/io.c | 365 +++++++++++++++++++++++++++++------------------------
1 file changed, 200 insertions(+), 165 deletions(-)
diff --git a/block/io.c b/block/io.c
index f656fb2dce..04e69400d8 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1415,28 +1415,177 @@ out:
}
/*
- * Handle a read request in coroutine context
+ * Request padding
+ *
+ * |<---- align ----->| |<----- align ---->|
+ * |<- head ->|<------------- bytes ------------->|<-- tail -->|
+ * | | | | | |
+ * -*----------$-------*-------- ... --------*-----$------------*---
+ * | | | | | |
+ * | offset | | end |
+ * ALIGN_DOWN(offset) ALIGN_UP(offset) ALIGN_DOWN(end) ALIGN_UP(end)
+ * [buf ... ) [tail_buf )
+ *
+ * @buf is an aligned allocation needed to store @head and @tail paddings. @head
+ * is placed at the beginning of @buf and @tail at the @end.
+ *
+ * @tail_buf is a pointer to sub-buffer, corresponding to align-sized chunk
+ * around tail, if tail exists.
+ *
+ * @merge_reads is true for small requests,
+ * if @buf_len == @head + bytes + @tail. In this case it is possible that both
+ * head and tail exist but @buf_len == align and @tail_buf == @buf.
*/
+typedef struct BdrvRequestPadding {
+ uint8_t *buf;
+ size_t buf_len;
+ uint8_t *tail_buf;
+ size_t head;
+ size_t tail;
+ bool merge_reads;
+ QEMUIOVector local_qiov;
+} BdrvRequestPadding;
+
+static bool bdrv_init_padding(BlockDriverState *bs,
+ int64_t offset, int64_t bytes,
+ BdrvRequestPadding *pad)
+{
+ uint64_t align = bs->bl.request_alignment;
+ size_t sum;
+
+ memset(pad, 0, sizeof(*pad));
+
+ pad->head = offset & (align - 1);
+ pad->tail = ((offset + bytes) & (align - 1));
+ if (pad->tail) {
+ pad->tail = align - pad->tail;
+ }
+
+ if ((!pad->head && !pad->tail) || !bytes) {
+ return false;
+ }
+
+ sum = pad->head + bytes + pad->tail;
+ pad->buf_len = (sum > align && pad->head && pad->tail) ? 2 * align : align;
+ pad->buf = qemu_blockalign(bs, pad->buf_len);
+ pad->merge_reads = sum == pad->buf_len;
+ if (pad->tail) {
+ pad->tail_buf = pad->buf + pad->buf_len - align;
+ }
+
+ return true;
+}
+
+static int bdrv_padding_rmw_read(BdrvChild *child,
+ BdrvTrackedRequest *req,
+ BdrvRequestPadding *pad,
+ bool zero_middle)
+{
+ QEMUIOVector local_qiov;
+ BlockDriverState *bs = child->bs;
+ uint64_t align = bs->bl.request_alignment;
+ int ret;
+
+ assert(req->serialising && pad->buf);
+
+ if (pad->head || pad->merge_reads) {
+ uint64_t bytes = pad->merge_reads ? pad->buf_len : align;
+
+ qemu_iovec_init_buf(&local_qiov, pad->buf, bytes);
+
+ if (pad->head) {
+ bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
+ }
+ if (pad->merge_reads && pad->tail) {
+ bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
+ }
+ ret = bdrv_aligned_preadv(child, req, req->overlap_offset, bytes,
+ align, &local_qiov, 0);
+ if (ret < 0) {
+ return ret;
+ }
+ if (pad->head) {
+ bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
+ }
+ if (pad->merge_reads && pad->tail) {
+ bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
+ }
+
+ if (pad->merge_reads) {
+ goto zero_mem;
+ }
+ }
+
+ if (pad->tail) {
+ qemu_iovec_init_buf(&local_qiov, pad->tail_buf, align);
+
+ bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
+ ret = bdrv_aligned_preadv(
+ child, req,
+ req->overlap_offset + req->overlap_bytes - align,
+ align, align, &local_qiov, 0);
+ if (ret < 0) {
+ return ret;
+ }
+ bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
+ }
+
+zero_mem:
+ if (zero_middle) {
+ memset(pad->buf + pad->head, 0, pad->buf_len - pad->head - pad->tail);
+ }
+
+ return 0;
+}
+
+static void bdrv_padding_destroy(BdrvRequestPadding *pad)
+{
+ if (pad->buf) {
+ qemu_vfree(pad->buf);
+ qemu_iovec_destroy(&pad->local_qiov);
+ }
+}
+
+/*
+ * bdrv_pad_request
+ *
+ * Exchange request parameters with padded request if needed. Don't include RMW
+ * read of padding, bdrv_padding_rmw_read() should be called separately if
+ * needed.
+ *
+ * All parameters except @bs are in-out: they represent original request at
+ * function call and padded (if padding needed) at function finish.
+ *
+ * Function always succeeds.
+ */
+static bool bdrv_pad_request(BlockDriverState *bs, QEMUIOVector **qiov,
+ int64_t *offset, unsigned int *bytes,
+ BdrvRequestPadding *pad)
+{
+ if (!bdrv_init_padding(bs, *offset, *bytes, pad)) {
+ return false;
+ }
+
+ qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head,
+ *qiov, 0, *bytes,
+ pad->buf + pad->buf_len - pad->tail, pad->tail);
+ *bytes += pad->head + pad->tail;
+ *offset -= pad->head;
+ *qiov = &pad->local_qiov;
+
+ return true;
+}
+
int coroutine_fn bdrv_co_preadv(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags)
{
BlockDriverState *bs = child->bs;
- BlockDriver *drv = bs->drv;
BdrvTrackedRequest req;
-
- uint64_t align = bs->bl.request_alignment;
- uint8_t *head_buf = NULL;
- uint8_t *tail_buf = NULL;
- QEMUIOVector local_qiov;
- bool use_local_qiov = false;
+ BdrvRequestPadding pad;
int ret;
- trace_bdrv_co_preadv(child->bs, offset, bytes, flags);
-
- if (!drv) {
- return -ENOMEDIUM;
- }
+ trace_bdrv_co_preadv(bs, offset, bytes, flags);
ret = bdrv_check_byte_request(bs, offset, bytes);
if (ret < 0) {
@@ -1450,43 +1599,16 @@ int coroutine_fn bdrv_co_preadv(BdrvChild *child,
flags |= BDRV_REQ_COPY_ON_READ;
}
- /* Align read if necessary by padding qiov */
- if (offset & (align - 1)) {
- head_buf = qemu_blockalign(bs, align);
- qemu_iovec_init(&local_qiov, qiov->niov + 2);
- qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
-
- bytes += offset & (align - 1);
- offset = offset & ~(align - 1);
- }
-
- if ((offset + bytes) & (align - 1)) {
- if (!use_local_qiov) {
- qemu_iovec_init(&local_qiov, qiov->niov + 1);
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
- }
- tail_buf = qemu_blockalign(bs, align);
- qemu_iovec_add(&local_qiov, tail_buf,
- align - ((offset + bytes) & (align - 1)));
-
- bytes = ROUND_UP(bytes, align);
- }
+ bdrv_pad_request(bs, &qiov, &offset, &bytes, &pad);
tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ);
- ret = bdrv_aligned_preadv(child, &req, offset, bytes, align,
- use_local_qiov ? &local_qiov : qiov,
- flags);
+ ret = bdrv_aligned_preadv(child, &req, offset, bytes,
+ bs->bl.request_alignment,
+ qiov, flags);
tracked_request_end(&req);
bdrv_dec_in_flight(bs);
- if (use_local_qiov) {
- qemu_iovec_destroy(&local_qiov);
- qemu_vfree(head_buf);
- qemu_vfree(tail_buf);
- }
+ bdrv_padding_destroy(&pad);
return ret;
}
@@ -1782,44 +1904,34 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
BdrvTrackedRequest *req)
{
BlockDriverState *bs = child->bs;
- uint8_t *buf = NULL;
QEMUIOVector local_qiov;
uint64_t align = bs->bl.request_alignment;
- unsigned int head_padding_bytes, tail_padding_bytes;
int ret = 0;
+ bool padding;
+ BdrvRequestPadding pad;
- head_padding_bytes = offset & (align - 1);
- tail_padding_bytes = (align - (offset + bytes)) & (align - 1);
-
-
- assert(flags & BDRV_REQ_ZERO_WRITE);
- if (head_padding_bytes || tail_padding_bytes) {
- buf = qemu_blockalign(bs, align);
- qemu_iovec_init_buf(&local_qiov, buf, align);
- }
- if (head_padding_bytes) {
- uint64_t zero_bytes = MIN(bytes, align - head_padding_bytes);
-
- /* RMW the unaligned part before head. */
+ padding = bdrv_init_padding(bs, offset, bytes, &pad);
+ if (padding) {
mark_request_serialising(req, align);
wait_serialising_requests(req);
- bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
- ret = bdrv_aligned_preadv(child, req, offset & ~(align - 1), align,
- align, &local_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
- memset(buf + head_padding_bytes, 0, zero_bytes);
- ret = bdrv_aligned_pwritev(child, req, offset & ~(align - 1), align,
- align, &local_qiov,
- flags & ~BDRV_REQ_ZERO_WRITE);
- if (ret < 0) {
- goto fail;
+ bdrv_padding_rmw_read(child, req, &pad, true);
+
+ if (pad.head || pad.merge_reads) {
+ int64_t aligned_offset = offset & ~(align - 1);
+ int64_t write_bytes = pad.merge_reads ? pad.buf_len : align;
+
+ qemu_iovec_init_buf(&local_qiov, pad.buf, write_bytes);
+ ret = bdrv_aligned_pwritev(child, req, aligned_offset, write_bytes,
+ align, &local_qiov,
+ flags & ~BDRV_REQ_ZERO_WRITE);
+ if (ret < 0 || pad.merge_reads) {
+ /* Error or all work is done */
+ goto out;
+ }
+ offset += write_bytes - pad.head;
+ bytes -= write_bytes - pad.head;
}
- offset += zero_bytes;
- bytes -= zero_bytes;
}
assert(!bytes || (offset & (align - 1)) == 0);
@@ -1829,7 +1941,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
ret = bdrv_aligned_pwritev(child, req, offset, aligned_bytes, align,
NULL, flags);
if (ret < 0) {
- goto fail;
+ goto out;
}
bytes -= aligned_bytes;
offset += aligned_bytes;
@@ -1837,26 +1949,17 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
assert(!bytes || (offset & (align - 1)) == 0);
if (bytes) {
- assert(align == tail_padding_bytes + bytes);
- /* RMW the unaligned part after tail. */
- mark_request_serialising(req, align);
- wait_serialising_requests(req);
- bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
- ret = bdrv_aligned_preadv(child, req, offset, align,
- align, &local_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
+ assert(align == pad.tail + bytes);
- memset(buf, 0, bytes);
+ qemu_iovec_init_buf(&local_qiov, pad.tail_buf, align);
ret = bdrv_aligned_pwritev(child, req, offset, align, align,
&local_qiov, flags & ~BDRV_REQ_ZERO_WRITE);
}
-fail:
- qemu_vfree(buf);
+
+out:
+ bdrv_padding_destroy(&pad);
+
return ret;
-
}
/*
@@ -1869,10 +1972,7 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
BlockDriverState *bs = child->bs;
BdrvTrackedRequest req;
uint64_t align = bs->bl.request_alignment;
- uint8_t *head_buf = NULL;
- uint8_t *tail_buf = NULL;
- QEMUIOVector local_qiov;
- bool use_local_qiov = false;
+ BdrvRequestPadding pad;
int ret;
trace_bdrv_co_pwritev(child->bs, offset, bytes, flags);
@@ -1899,86 +1999,21 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
goto out;
}
- if (offset & (align - 1)) {
- QEMUIOVector head_qiov;
-
+ if (bdrv_pad_request(bs, &qiov, &offset, &bytes, &pad)) {
mark_request_serialising(&req, align);
wait_serialising_requests(&req);
-
- head_buf = qemu_blockalign(bs, align);
- qemu_iovec_init_buf(&head_qiov, head_buf, align);
-
- bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
- ret = bdrv_aligned_preadv(child, &req, offset & ~(align - 1), align,
- align, &head_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
-
- qemu_iovec_init(&local_qiov, qiov->niov + 2);
- qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
-
- bytes += offset & (align - 1);
- offset = offset & ~(align - 1);
-
- /* We have read the tail already if the request is smaller
- * than one aligned block.
- */
- if (bytes < align) {
- qemu_iovec_add(&local_qiov, head_buf + bytes, align - bytes);
- bytes = align;
- }
- }
-
- if ((offset + bytes) & (align - 1)) {
- QEMUIOVector tail_qiov;
- size_t tail_bytes;
- bool waited;
-
- mark_request_serialising(&req, align);
- waited = wait_serialising_requests(&req);
- assert(!waited || !use_local_qiov);
-
- tail_buf = qemu_blockalign(bs, align);
- qemu_iovec_init_buf(&tail_qiov, tail_buf, align);
-
- bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
- ret = bdrv_aligned_preadv(child, &req, (offset + bytes) & ~(align - 1),
- align, align, &tail_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
-
- if (!use_local_qiov) {
- qemu_iovec_init(&local_qiov, qiov->niov + 1);
- qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
- use_local_qiov = true;
- }
-
- tail_bytes = (offset + bytes) & (align - 1);
- qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes);
-
- bytes = ROUND_UP(bytes, align);
+ bdrv_padding_rmw_read(child, &req, &pad, false);
}
ret = bdrv_aligned_pwritev(child, &req, offset, bytes, align,
- use_local_qiov ? &local_qiov : qiov,
- flags);
+ qiov, flags);
-fail:
+ bdrv_padding_destroy(&pad);
- if (use_local_qiov) {
- qemu_iovec_destroy(&local_qiov);
- }
- qemu_vfree(head_buf);
- qemu_vfree(tail_buf);
out:
tracked_request_end(&req);
bdrv_dec_in_flight(bs);
+
return ret;
}
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 04/12] block: define .*_part io handlers in BlockDriver
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (2 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 03/12] block/io: refactor padding Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 05/12] block/io: bdrv_co_do_copy_on_readv: use and support qiov_offset Stefan Hajnoczi
` (8 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Add handlers supporting qiov_offset parameter:
bdrv_co_preadv_part
bdrv_co_pwritev_part
bdrv_co_pwritev_compressed_part
This is used to reduce need of defining local_qiovs and hd_qiovs in all
corners of block layer code. The following patches will increase usage
of this new API part by part.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-5-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-5-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/block/block_int.h | 15 ++++++
block/backup.c | 2 +-
block/io.c | 96 +++++++++++++++++++++++++++++++--------
qemu-img.c | 4 +-
4 files changed, 95 insertions(+), 22 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index ceec8c2f56..79a1fdb258 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -210,6 +210,9 @@ struct BlockDriver {
*/
int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
+ int coroutine_fn (*bdrv_co_preadv_part)(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, int flags);
int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
/**
@@ -229,6 +232,9 @@ struct BlockDriver {
*/
int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
+ int coroutine_fn (*bdrv_co_pwritev_part)(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, int flags);
/*
* Efficiently zero a region of the disk image. Typically an image format
@@ -339,6 +345,9 @@ struct BlockDriver {
int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs,
uint64_t offset, uint64_t bytes, QEMUIOVector *qiov);
+ int coroutine_fn (*bdrv_co_pwritev_compressed_part)(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
+ size_t qiov_offset);
int (*bdrv_snapshot_create)(BlockDriverState *bs,
QEMUSnapshotInfo *sn_info);
@@ -570,6 +579,12 @@ struct BlockDriver {
const char *const *strong_runtime_opts;
};
+static inline bool block_driver_can_compress(BlockDriver *drv)
+{
+ return drv->bdrv_co_pwritev_compressed ||
+ drv->bdrv_co_pwritev_compressed_part;
+}
+
typedef struct BlockLimits {
/* Alignment requirement, in bytes, for offset/length of I/O
* requests. Must be a power of 2 less than INT_MAX; defaults to
diff --git a/block/backup.c b/block/backup.c
index 2baf7bed65..03637aeb11 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -674,7 +674,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
return NULL;
}
- if (compress && target->drv->bdrv_co_pwritev_compressed == NULL) {
+ if (compress && !block_driver_can_compress(target->drv)) {
error_setg(errp, "Compression is not supported for this drive %s",
bdrv_get_device_name(target));
return NULL;
diff --git a/block/io.c b/block/io.c
index 04e69400d8..fd2fc7d5ff 100644
--- a/block/io.c
+++ b/block/io.c
@@ -146,7 +146,8 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
/* Default alignment based on whether driver has byte interface */
bs->bl.request_alignment = (drv->bdrv_co_preadv ||
- drv->bdrv_aio_preadv) ? 1 : 512;
+ drv->bdrv_aio_preadv ||
+ drv->bdrv_co_preadv_part) ? 1 : 512;
/* Take some limits from the children as a default */
if (bs->file) {
@@ -1044,11 +1045,14 @@ static void bdrv_co_io_em_complete(void *opaque, int ret)
static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
- QEMUIOVector *qiov, int flags)
+ QEMUIOVector *qiov,
+ size_t qiov_offset, int flags)
{
BlockDriver *drv = bs->drv;
int64_t sector_num;
unsigned int nb_sectors;
+ QEMUIOVector local_qiov;
+ int ret;
assert(!(flags & ~BDRV_REQ_MASK));
assert(!(flags & BDRV_REQ_NO_FALLBACK));
@@ -1057,8 +1061,19 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
return -ENOMEDIUM;
}
+ if (drv->bdrv_co_preadv_part) {
+ return drv->bdrv_co_preadv_part(bs, offset, bytes, qiov, qiov_offset,
+ flags);
+ }
+
+ if (qiov_offset > 0 || bytes != qiov->size) {
+ qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes);
+ qiov = &local_qiov;
+ }
+
if (drv->bdrv_co_preadv) {
- return drv->bdrv_co_preadv(bs, offset, bytes, qiov, flags);
+ ret = drv->bdrv_co_preadv(bs, offset, bytes, qiov, flags);
+ goto out;
}
if (drv->bdrv_aio_preadv) {
@@ -1070,10 +1085,12 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
acb = drv->bdrv_aio_preadv(bs, offset, bytes, qiov, flags,
bdrv_co_io_em_complete, &co);
if (acb == NULL) {
- return -EIO;
+ ret = -EIO;
+ goto out;
} else {
qemu_coroutine_yield();
- return co.ret;
+ ret = co.ret;
+ goto out;
}
}
@@ -1085,16 +1102,25 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
assert(bytes <= BDRV_REQUEST_MAX_BYTES);
assert(drv->bdrv_co_readv);
- return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+ ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+
+out:
+ if (qiov == &local_qiov) {
+ qemu_iovec_destroy(&local_qiov);
+ }
+
+ return ret;
}
static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
- QEMUIOVector *qiov, int flags)
+ QEMUIOVector *qiov,
+ size_t qiov_offset, int flags)
{
BlockDriver *drv = bs->drv;
int64_t sector_num;
unsigned int nb_sectors;
+ QEMUIOVector local_qiov;
int ret;
assert(!(flags & ~BDRV_REQ_MASK));
@@ -1104,6 +1130,18 @@ static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
return -ENOMEDIUM;
}
+ if (drv->bdrv_co_pwritev_part) {
+ ret = drv->bdrv_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset,
+ flags & bs->supported_write_flags);
+ flags &= ~bs->supported_write_flags;
+ goto emulate_flags;
+ }
+
+ if (qiov_offset > 0 || bytes != qiov->size) {
+ qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes);
+ qiov = &local_qiov;
+ }
+
if (drv->bdrv_co_pwritev) {
ret = drv->bdrv_co_pwritev(bs, offset, bytes, qiov,
flags & bs->supported_write_flags);
@@ -1147,24 +1185,44 @@ emulate_flags:
ret = bdrv_co_flush(bs);
}
+ if (qiov == &local_qiov) {
+ qemu_iovec_destroy(&local_qiov);
+ }
+
return ret;
}
static int coroutine_fn
bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
- uint64_t bytes, QEMUIOVector *qiov)
+ uint64_t bytes, QEMUIOVector *qiov,
+ size_t qiov_offset)
{
BlockDriver *drv = bs->drv;
+ QEMUIOVector local_qiov;
+ int ret;
if (!drv) {
return -ENOMEDIUM;
}
- if (!drv->bdrv_co_pwritev_compressed) {
+ if (!block_driver_can_compress(drv)) {
return -ENOTSUP;
}
- return drv->bdrv_co_pwritev_compressed(bs, offset, bytes, qiov);
+ if (drv->bdrv_co_pwritev_compressed_part) {
+ return drv->bdrv_co_pwritev_compressed_part(bs, offset, bytes,
+ qiov, qiov_offset);
+ }
+
+ if (qiov_offset == 0) {
+ return drv->bdrv_co_pwritev_compressed(bs, offset, bytes, qiov);
+ }
+
+ qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes);
+ ret = drv->bdrv_co_pwritev_compressed(bs, offset, bytes, &local_qiov);
+ qemu_iovec_destroy(&local_qiov);
+
+ return ret;
}
static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
@@ -1249,7 +1307,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum);
ret = bdrv_driver_preadv(bs, cluster_offset, pnum,
- &local_qiov, 0);
+ &local_qiov, 0, 0);
if (ret < 0) {
goto err;
}
@@ -1267,7 +1325,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
* necessary to flush even in cache=writethrough mode.
*/
ret = bdrv_driver_pwritev(bs, cluster_offset, pnum,
- &local_qiov,
+ &local_qiov, 0,
BDRV_REQ_WRITE_UNCHANGED);
}
@@ -1289,7 +1347,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
qemu_iovec_init(&local_qiov, qiov->niov);
qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes);
ret = bdrv_driver_preadv(bs, offset + progress, local_qiov.size,
- &local_qiov, 0);
+ &local_qiov, 0, 0);
qemu_iovec_destroy(&local_qiov);
if (ret < 0) {
goto err;
@@ -1380,7 +1438,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align);
if (bytes <= max_bytes && bytes <= max_transfer) {
- ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0);
+ ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0, 0);
goto out;
}
@@ -1396,7 +1454,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num);
ret = bdrv_driver_preadv(bs, offset + bytes - bytes_remaining,
- num, &local_qiov, 0);
+ num, &local_qiov, 0, 0);
max_bytes -= num;
qemu_iovec_destroy(&local_qiov);
} else {
@@ -1701,7 +1759,7 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
}
qemu_iovec_init_buf(&qiov, buf, num);
- ret = bdrv_driver_pwritev(bs, offset, num, &qiov, write_flags);
+ ret = bdrv_driver_pwritev(bs, offset, num, &qiov, 0, write_flags);
/* Keep bounce buffer around if it is big enough for all
* all future requests.
@@ -1857,10 +1915,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO);
ret = bdrv_co_do_pwrite_zeroes(bs, offset, bytes, flags);
} else if (flags & BDRV_REQ_WRITE_COMPRESSED) {
- ret = bdrv_driver_pwritev_compressed(bs, offset, bytes, qiov);
+ ret = bdrv_driver_pwritev_compressed(bs, offset, bytes, qiov, 0);
} else if (bytes <= max_transfer) {
bdrv_debug_event(bs, BLKDBG_PWRITEV);
- ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, flags);
+ ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, 0, flags);
} else {
bdrv_debug_event(bs, BLKDBG_PWRITEV);
while (bytes_remaining) {
@@ -1879,7 +1937,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num);
ret = bdrv_driver_pwritev(bs, offset + bytes - bytes_remaining,
- num, &local_qiov, local_flags);
+ num, &local_qiov, 0, local_flags);
qemu_iovec_destroy(&local_qiov);
if (ret < 0) {
break;
diff --git a/qemu-img.c b/qemu-img.c
index 7daa05e51a..4ee436fc94 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2388,7 +2388,7 @@ static int img_convert(int argc, char **argv)
const char *preallocation =
qemu_opt_get(opts, BLOCK_OPT_PREALLOC);
- if (drv && !drv->bdrv_co_pwritev_compressed) {
+ if (drv && !block_driver_can_compress(drv)) {
error_report("Compression not supported for this file format");
ret = -1;
goto out;
@@ -2459,7 +2459,7 @@ static int img_convert(int argc, char **argv)
}
out_bs = blk_bs(s.target);
- if (s.compressed && !out_bs->drv->bdrv_co_pwritev_compressed) {
+ if (s.compressed && !block_driver_can_compress(out_bs->drv)) {
error_report("Compression not supported for this file format");
ret = -1;
goto out;
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 05/12] block/io: bdrv_co_do_copy_on_readv: use and support qiov_offset
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (3 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 04/12] block: define .*_part io handlers in BlockDriver Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 06/12] block/io: bdrv_co_do_copy_on_readv: lazy allocation Stefan Hajnoczi
` (7 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Use and support new API in bdrv_co_do_copy_on_readv. Note that in case
of allocated-in-top we need to shrink read size to MIN(..) by hand, as
pre-patch this was actually done implicitly by qemu_iovec_concat (and
we used local_qiov.size).
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-6-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-6-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/io.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/block/io.c b/block/io.c
index fd2fc7d5ff..5817bb9405 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1227,7 +1227,7 @@ bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
- int flags)
+ size_t qiov_offset, int flags)
{
BlockDriverState *bs = child->bs;
@@ -1239,7 +1239,6 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
void *bounce_buffer;
BlockDriver *drv = bs->drv;
- QEMUIOVector local_qiov;
int64_t cluster_offset;
int64_t cluster_bytes;
size_t skip_bytes;
@@ -1302,6 +1301,8 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
assert(skip_bytes < pnum);
if (ret <= 0) {
+ QEMUIOVector local_qiov;
+
/* Must copy-on-read; use the bounce buffer */
pnum = MIN(pnum, MAX_BOUNCE_BUFFER);
qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum);
@@ -1339,16 +1340,15 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
}
if (!(flags & BDRV_REQ_PREFETCH)) {
- qemu_iovec_from_buf(qiov, progress, bounce_buffer + skip_bytes,
+ qemu_iovec_from_buf(qiov, qiov_offset + progress,
+ bounce_buffer + skip_bytes,
pnum - skip_bytes);
}
} else if (!(flags & BDRV_REQ_PREFETCH)) {
/* Read directly into the destination */
- qemu_iovec_init(&local_qiov, qiov->niov);
- qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes);
- ret = bdrv_driver_preadv(bs, offset + progress, local_qiov.size,
- &local_qiov, 0, 0);
- qemu_iovec_destroy(&local_qiov);
+ ret = bdrv_driver_preadv(bs, offset + progress,
+ MIN(pnum - skip_bytes, bytes - progress),
+ qiov, qiov_offset + progress, 0);
if (ret < 0) {
goto err;
}
@@ -1422,7 +1422,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
}
if (!ret || pnum != bytes) {
- ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, flags);
+ ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, 0, flags);
goto out;
} else if (flags & BDRV_REQ_PREFETCH) {
goto out;
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 06/12] block/io: bdrv_co_do_copy_on_readv: lazy allocation
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (4 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 05/12] block/io: bdrv_co_do_copy_on_readv: use and support qiov_offset Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 07/12] block/io: bdrv_aligned_preadv: use and support qiov_offset Stefan Hajnoczi
` (6 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Allocate bounce_buffer only if it is really needed. Also, sub-optimize
allocation size (why not?).
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-7-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-7-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/io.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
diff --git a/block/io.c b/block/io.c
index 5817bb9405..4c7a7ac7b1 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1236,7 +1236,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
* modifying the image file. This is critical for zero-copy guest I/O
* where anything might happen inside guest memory.
*/
- void *bounce_buffer;
+ void *bounce_buffer = NULL;
BlockDriver *drv = bs->drv;
int64_t cluster_offset;
@@ -1271,14 +1271,6 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
trace_bdrv_co_do_copy_on_readv(bs, offset, bytes,
cluster_offset, cluster_bytes);
- bounce_buffer = qemu_try_blockalign(bs,
- MIN(MIN(max_transfer, cluster_bytes),
- MAX_BOUNCE_BUFFER));
- if (bounce_buffer == NULL) {
- ret = -ENOMEM;
- goto err;
- }
-
while (cluster_bytes) {
int64_t pnum;
@@ -1305,6 +1297,17 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
/* Must copy-on-read; use the bounce buffer */
pnum = MIN(pnum, MAX_BOUNCE_BUFFER);
+ if (!bounce_buffer) {
+ int64_t max_we_need = MAX(pnum, cluster_bytes - pnum);
+ int64_t max_allowed = MIN(max_transfer, MAX_BOUNCE_BUFFER);
+ int64_t bounce_buffer_len = MIN(max_we_need, max_allowed);
+
+ bounce_buffer = qemu_try_blockalign(bs, bounce_buffer_len);
+ if (!bounce_buffer) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ }
qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum);
ret = bdrv_driver_preadv(bs, cluster_offset, pnum,
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 07/12] block/io: bdrv_aligned_preadv: use and support qiov_offset
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (5 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 06/12] block/io: bdrv_co_do_copy_on_readv: lazy allocation Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 08/12] block/io: bdrv_aligned_pwritev: " Stefan Hajnoczi
` (5 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Use and support new API in bdrv_co_do_copy_on_readv.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-8-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-8-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/io.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/block/io.c b/block/io.c
index 4c7a7ac7b1..f191a3fa1e 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1376,7 +1376,7 @@ err:
*/
static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
- int64_t align, QEMUIOVector *qiov, int flags)
+ int64_t align, QEMUIOVector *qiov, size_t qiov_offset, int flags)
{
BlockDriverState *bs = child->bs;
int64_t total_bytes, max_bytes;
@@ -1387,7 +1387,6 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
assert(is_power_of_2(align));
assert((offset & (align - 1)) == 0);
assert((bytes & (align - 1)) == 0);
- assert(!qiov || bytes == qiov->size);
assert((bs->open_flags & BDRV_O_NO_IO) == 0);
max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX),
align);
@@ -1425,7 +1424,8 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
}
if (!ret || pnum != bytes) {
- ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, 0, flags);
+ ret = bdrv_co_do_copy_on_readv(child, offset, bytes,
+ qiov, qiov_offset, flags);
goto out;
} else if (flags & BDRV_REQ_PREFETCH) {
goto out;
@@ -1441,7 +1441,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align);
if (bytes <= max_bytes && bytes <= max_transfer) {
- ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0, 0);
+ ret = bdrv_driver_preadv(bs, offset, bytes, qiov, qiov_offset, 0);
goto out;
}
@@ -1449,17 +1449,12 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
int num;
if (max_bytes) {
- QEMUIOVector local_qiov;
-
num = MIN(bytes_remaining, MIN(max_bytes, max_transfer));
assert(num);
- qemu_iovec_init(&local_qiov, qiov->niov);
- qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num);
ret = bdrv_driver_preadv(bs, offset + bytes - bytes_remaining,
- num, &local_qiov, 0, 0);
+ num, qiov, bytes - bytes_remaining, 0);
max_bytes -= num;
- qemu_iovec_destroy(&local_qiov);
} else {
num = bytes_remaining;
ret = qemu_iovec_memset(qiov, bytes - bytes_remaining, 0,
@@ -1561,7 +1556,7 @@ static int bdrv_padding_rmw_read(BdrvChild *child,
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
}
ret = bdrv_aligned_preadv(child, req, req->overlap_offset, bytes,
- align, &local_qiov, 0);
+ align, &local_qiov, 0, 0);
if (ret < 0) {
return ret;
}
@@ -1584,7 +1579,7 @@ static int bdrv_padding_rmw_read(BdrvChild *child,
ret = bdrv_aligned_preadv(
child, req,
req->overlap_offset + req->overlap_bytes - align,
- align, align, &local_qiov, 0);
+ align, align, &local_qiov, 0, 0);
if (ret < 0) {
return ret;
}
@@ -1665,7 +1660,7 @@ int coroutine_fn bdrv_co_preadv(BdrvChild *child,
tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ);
ret = bdrv_aligned_preadv(child, &req, offset, bytes,
bs->bl.request_alignment,
- qiov, flags);
+ qiov, 0, flags);
tracked_request_end(&req);
bdrv_dec_in_flight(bs);
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 08/12] block/io: bdrv_aligned_pwritev: use and support qiov_offset
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (6 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 07/12] block/io: bdrv_aligned_preadv: use and support qiov_offset Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 09/12] block/io: introduce bdrv_co_p{read, write}v_part Stefan Hajnoczi
` (4 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Use and support new API in bdrv_aligned_pwritev.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-9-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-9-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/io.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/block/io.c b/block/io.c
index f191a3fa1e..237d7f40f5 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1872,7 +1872,7 @@ bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, uint64_t bytes,
*/
static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
- int64_t align, QEMUIOVector *qiov, int flags)
+ int64_t align, QEMUIOVector *qiov, size_t qiov_offset, int flags)
{
BlockDriverState *bs = child->bs;
BlockDriver *drv = bs->drv;
@@ -1892,7 +1892,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
assert(is_power_of_2(align));
assert((offset & (align - 1)) == 0);
assert((bytes & (align - 1)) == 0);
- assert(!qiov || bytes == qiov->size);
+ assert(!qiov || qiov_offset + bytes <= qiov->size);
max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX),
align);
@@ -1900,7 +1900,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
!(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_pwrite_zeroes &&
- qemu_iovec_is_zero(qiov, 0, qiov->size)) {
+ qemu_iovec_is_zero(qiov, qiov_offset, bytes)) {
flags |= BDRV_REQ_ZERO_WRITE;
if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
flags |= BDRV_REQ_MAY_UNMAP;
@@ -1913,15 +1913,15 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO);
ret = bdrv_co_do_pwrite_zeroes(bs, offset, bytes, flags);
} else if (flags & BDRV_REQ_WRITE_COMPRESSED) {
- ret = bdrv_driver_pwritev_compressed(bs, offset, bytes, qiov, 0);
+ ret = bdrv_driver_pwritev_compressed(bs, offset, bytes,
+ qiov, qiov_offset);
} else if (bytes <= max_transfer) {
bdrv_debug_event(bs, BLKDBG_PWRITEV);
- ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, 0, flags);
+ ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, qiov_offset, flags);
} else {
bdrv_debug_event(bs, BLKDBG_PWRITEV);
while (bytes_remaining) {
int num = MIN(bytes_remaining, max_transfer);
- QEMUIOVector local_qiov;
int local_flags = flags;
assert(num);
@@ -1931,12 +1931,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
* need to flush on the last iteration */
local_flags &= ~BDRV_REQ_FUA;
}
- qemu_iovec_init(&local_qiov, qiov->niov);
- qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num);
ret = bdrv_driver_pwritev(bs, offset + bytes - bytes_remaining,
- num, &local_qiov, 0, local_flags);
- qemu_iovec_destroy(&local_qiov);
+ num, qiov, bytes - bytes_remaining,
+ local_flags);
if (ret < 0) {
break;
}
@@ -1979,7 +1977,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
qemu_iovec_init_buf(&local_qiov, pad.buf, write_bytes);
ret = bdrv_aligned_pwritev(child, req, aligned_offset, write_bytes,
- align, &local_qiov,
+ align, &local_qiov, 0,
flags & ~BDRV_REQ_ZERO_WRITE);
if (ret < 0 || pad.merge_reads) {
/* Error or all work is done */
@@ -1995,7 +1993,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
/* Write the aligned part in the middle. */
uint64_t aligned_bytes = bytes & ~(align - 1);
ret = bdrv_aligned_pwritev(child, req, offset, aligned_bytes, align,
- NULL, flags);
+ NULL, 0, flags);
if (ret < 0) {
goto out;
}
@@ -2009,7 +2007,8 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
qemu_iovec_init_buf(&local_qiov, pad.tail_buf, align);
ret = bdrv_aligned_pwritev(child, req, offset, align, align,
- &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE);
+ &local_qiov, 0,
+ flags & ~BDRV_REQ_ZERO_WRITE);
}
out:
@@ -2062,7 +2061,7 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
}
ret = bdrv_aligned_pwritev(child, &req, offset, bytes, align,
- qiov, flags);
+ qiov, 0, flags);
bdrv_padding_destroy(&pad);
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 09/12] block/io: introduce bdrv_co_p{read, write}v_part
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (7 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 08/12] block/io: bdrv_aligned_pwritev: " Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 10/12] block/qcow2: refactor qcow2_co_preadv to use buffer-based io Stefan Hajnoczi
` (3 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Introduce extended variants of bdrv_co_preadv and bdrv_co_pwritev
with qiov_offset parameter.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-10-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-10-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/block/block_int.h | 6 ++++++
block/io.c | 29 +++++++++++++++++++++++------
2 files changed, 29 insertions(+), 6 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 79a1fdb258..0422acdf1c 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -959,9 +959,15 @@ extern BlockDriver bdrv_qcow2;
int coroutine_fn bdrv_co_preadv(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
+int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
+ int64_t offset, unsigned int bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
+int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
+ int64_t offset, unsigned int bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
static inline int coroutine_fn bdrv_co_pread(BdrvChild *child,
int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
diff --git a/block/io.c b/block/io.c
index 237d7f40f5..0fa10831ed 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1614,7 +1614,8 @@ static void bdrv_padding_destroy(BdrvRequestPadding *pad)
*
* Function always succeeds.
*/
-static bool bdrv_pad_request(BlockDriverState *bs, QEMUIOVector **qiov,
+static bool bdrv_pad_request(BlockDriverState *bs,
+ QEMUIOVector **qiov, size_t *qiov_offset,
int64_t *offset, unsigned int *bytes,
BdrvRequestPadding *pad)
{
@@ -1623,11 +1624,12 @@ static bool bdrv_pad_request(BlockDriverState *bs, QEMUIOVector **qiov,
}
qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head,
- *qiov, 0, *bytes,
+ *qiov, *qiov_offset, *bytes,
pad->buf + pad->buf_len - pad->tail, pad->tail);
*bytes += pad->head + pad->tail;
*offset -= pad->head;
*qiov = &pad->local_qiov;
+ *qiov_offset = 0;
return true;
}
@@ -1635,6 +1637,14 @@ static bool bdrv_pad_request(BlockDriverState *bs, QEMUIOVector **qiov,
int coroutine_fn bdrv_co_preadv(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags)
+{
+ return bdrv_co_preadv_part(child, offset, bytes, qiov, 0, flags);
+}
+
+int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
+ int64_t offset, unsigned int bytes,
+ QEMUIOVector *qiov, size_t qiov_offset,
+ BdrvRequestFlags flags)
{
BlockDriverState *bs = child->bs;
BdrvTrackedRequest req;
@@ -1655,12 +1665,12 @@ int coroutine_fn bdrv_co_preadv(BdrvChild *child,
flags |= BDRV_REQ_COPY_ON_READ;
}
- bdrv_pad_request(bs, &qiov, &offset, &bytes, &pad);
+ bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad);
tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ);
ret = bdrv_aligned_preadv(child, &req, offset, bytes,
bs->bl.request_alignment,
- qiov, 0, flags);
+ qiov, qiov_offset, flags);
tracked_request_end(&req);
bdrv_dec_in_flight(bs);
@@ -2023,6 +2033,13 @@ out:
int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags)
+{
+ return bdrv_co_pwritev_part(child, offset, bytes, qiov, 0, flags);
+}
+
+int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov, size_t qiov_offset,
+ BdrvRequestFlags flags)
{
BlockDriverState *bs = child->bs;
BdrvTrackedRequest req;
@@ -2054,14 +2071,14 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
goto out;
}
- if (bdrv_pad_request(bs, &qiov, &offset, &bytes, &pad)) {
+ if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) {
mark_request_serialising(&req, align);
wait_serialising_requests(&req);
bdrv_padding_rmw_read(child, &req, &pad, false);
}
ret = bdrv_aligned_pwritev(child, &req, offset, bytes, align,
- qiov, 0, flags);
+ qiov, qiov_offset, flags);
bdrv_padding_destroy(&pad);
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 10/12] block/qcow2: refactor qcow2_co_preadv to use buffer-based io
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (8 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 09/12] block/io: introduce bdrv_co_p{read, write}v_part Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 11/12] block/qcow2: implement .bdrv_co_preadv_part Stefan Hajnoczi
` (2 subsequent siblings)
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Use buffer based io in encrypted case.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-11-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-11-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/qcow2.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 7c5a4859f7..b2b87d1a8d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2059,19 +2059,15 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
}
assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
- qemu_iovec_reset(&hd_qiov);
- qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes);
- }
- BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
- ret = bdrv_co_preadv(s->data_file,
- cluster_offset + offset_in_cluster,
- cur_bytes, &hd_qiov, 0);
- if (ret < 0) {
- goto fail;
- }
- if (bs->encrypted) {
- assert(s->crypto);
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ ret = bdrv_co_pread(s->data_file,
+ cluster_offset + offset_in_cluster,
+ cur_bytes, cluster_data, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
if (qcow2_co_decrypt(bs, cluster_offset, offset,
@@ -2080,6 +2076,14 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
goto fail;
}
qemu_iovec_from_buf(qiov, bytes_done, cluster_data, cur_bytes);
+ } else {
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ ret = bdrv_co_preadv(s->data_file,
+ cluster_offset + offset_in_cluster,
+ cur_bytes, &hd_qiov, 0);
+ if (ret < 0) {
+ goto fail;
+ }
}
break;
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 11/12] block/qcow2: implement .bdrv_co_preadv_part
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (9 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 10/12] block/qcow2: refactor qcow2_co_preadv to use buffer-based io Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-08-27 20:16 ` [Qemu-devel] [PULL 12/12] block/qcow2: implement .bdrv_co_pwritev(_compressed)_part Stefan Hajnoczi
2019-09-03 10:05 ` [Qemu-devel] [PULL 00/12] Block patches Peter Maydell
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Implement and use new interface to get rid of hd_qiov.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-12-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-12-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/qcow2-cluster.c | 5 +++--
block/qcow2.c | 49 +++++++++++++++++++------------------------
2 files changed, 25 insertions(+), 29 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index cc5609e27a..0e4524d450 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -452,8 +452,9 @@ static int coroutine_fn do_perform_cow_read(BlockDriverState *bs,
* interface. This avoids double I/O throttling and request tracking,
* which can lead to deadlock when block layer copy-on-read is enabled.
*/
- ret = bs->drv->bdrv_co_preadv(bs, src_cluster_offset + offset_in_cluster,
- qiov->size, qiov, 0);
+ ret = bs->drv->bdrv_co_preadv_part(bs,
+ src_cluster_offset + offset_in_cluster,
+ qiov->size, qiov, 0, 0);
if (ret < 0) {
return ret;
}
diff --git a/block/qcow2.c b/block/qcow2.c
index b2b87d1a8d..ec1fff9dd1 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -76,7 +76,8 @@ qcow2_co_preadv_compressed(BlockDriverState *bs,
uint64_t file_cluster_offset,
uint64_t offset,
uint64_t bytes,
- QEMUIOVector *qiov);
+ QEMUIOVector *qiov,
+ size_t qiov_offset);
static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
{
@@ -1967,21 +1968,18 @@ out:
return ret;
}
-static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
- uint64_t bytes, QEMUIOVector *qiov,
- int flags)
+static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes,
+ QEMUIOVector *qiov,
+ size_t qiov_offset, int flags)
{
BDRVQcow2State *s = bs->opaque;
int offset_in_cluster;
int ret;
unsigned int cur_bytes; /* number of bytes in current iteration */
uint64_t cluster_offset = 0;
- uint64_t bytes_done = 0;
- QEMUIOVector hd_qiov;
uint8_t *cluster_data = NULL;
- qemu_iovec_init(&hd_qiov, qiov->niov);
-
while (bytes != 0) {
/* prepare next request */
@@ -2000,34 +1998,31 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
offset_in_cluster = offset_into_cluster(s, offset);
- qemu_iovec_reset(&hd_qiov);
- qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes);
-
switch (ret) {
case QCOW2_CLUSTER_UNALLOCATED:
if (bs->backing) {
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
- ret = bdrv_co_preadv(bs->backing, offset, cur_bytes,
- &hd_qiov, 0);
+ ret = bdrv_co_preadv_part(bs->backing, offset, cur_bytes,
+ qiov, qiov_offset, 0);
if (ret < 0) {
goto fail;
}
} else {
/* Note: in this case, no need to wait */
- qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes);
+ qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes);
}
break;
case QCOW2_CLUSTER_ZERO_PLAIN:
case QCOW2_CLUSTER_ZERO_ALLOC:
- qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes);
+ qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes);
break;
case QCOW2_CLUSTER_COMPRESSED:
ret = qcow2_co_preadv_compressed(bs, cluster_offset,
offset, cur_bytes,
- &hd_qiov);
+ qiov, qiov_offset);
if (ret < 0) {
goto fail;
}
@@ -2075,12 +2070,12 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
ret = -EIO;
goto fail;
}
- qemu_iovec_from_buf(qiov, bytes_done, cluster_data, cur_bytes);
+ qemu_iovec_from_buf(qiov, qiov_offset, cluster_data, cur_bytes);
} else {
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
- ret = bdrv_co_preadv(s->data_file,
- cluster_offset + offset_in_cluster,
- cur_bytes, &hd_qiov, 0);
+ ret = bdrv_co_preadv_part(s->data_file,
+ cluster_offset + offset_in_cluster,
+ cur_bytes, qiov, qiov_offset, 0);
if (ret < 0) {
goto fail;
}
@@ -2095,12 +2090,11 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
bytes -= cur_bytes;
offset += cur_bytes;
- bytes_done += cur_bytes;
+ qiov_offset += cur_bytes;
}
ret = 0;
fail:
- qemu_iovec_destroy(&hd_qiov);
qemu_vfree(cluster_data);
return ret;
@@ -4101,7 +4095,8 @@ qcow2_co_preadv_compressed(BlockDriverState *bs,
uint64_t file_cluster_offset,
uint64_t offset,
uint64_t bytes,
- QEMUIOVector *qiov)
+ QEMUIOVector *qiov,
+ size_t qiov_offset)
{
BDRVQcow2State *s = bs->opaque;
int ret = 0, csize, nb_csectors;
@@ -4132,7 +4127,7 @@ qcow2_co_preadv_compressed(BlockDriverState *bs,
goto fail;
}
- qemu_iovec_from_buf(qiov, 0, out_buf + offset_in_cluster, bytes);
+ qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes);
fail:
qemu_vfree(out_buf);
@@ -4679,8 +4674,8 @@ static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
BDRVQcow2State *s = bs->opaque;
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
- return bs->drv->bdrv_co_preadv(bs, qcow2_vm_state_offset(s) + pos,
- qiov->size, qiov, 0);
+ return bs->drv->bdrv_co_preadv_part(bs, qcow2_vm_state_offset(s) + pos,
+ qiov->size, qiov, 0, 0);
}
/*
@@ -5222,7 +5217,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_has_zero_init_truncate = bdrv_has_zero_init_1,
.bdrv_co_block_status = qcow2_co_block_status,
- .bdrv_co_preadv = qcow2_co_preadv,
+ .bdrv_co_preadv_part = qcow2_co_preadv_part,
.bdrv_co_pwritev = qcow2_co_pwritev,
.bdrv_co_flush_to_os = qcow2_co_flush_to_os,
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* [Qemu-devel] [PULL 12/12] block/qcow2: implement .bdrv_co_pwritev(_compressed)_part
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (10 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 11/12] block/qcow2: implement .bdrv_co_preadv_part Stefan Hajnoczi
@ 2019-08-27 20:16 ` Stefan Hajnoczi
2019-09-03 10:05 ` [Qemu-devel] [PULL 00/12] Block patches Peter Maydell
12 siblings, 0 replies; 16+ messages in thread
From: Stefan Hajnoczi @ 2019-08-27 20:16 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Kevin Wolf, Vladimir Sementsov-Ogievskiy, qemu-block,
Peter Maydell, Max Reitz, Stefan Hajnoczi, John Snow
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Implement and use new interface to get rid of hd_qiov.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-13-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-13-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/qcow2.h | 1 +
include/qemu/iov.h | 1 +
block/qcow2-cluster.c | 9 ++++---
block/qcow2.c | 60 +++++++++++++++++++++----------------------
util/iov.c | 10 ++++++++
5 files changed, 48 insertions(+), 33 deletions(-)
diff --git a/block/qcow2.h b/block/qcow2.h
index fc1b0d3c1e..998bcdaef1 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -420,6 +420,7 @@ typedef struct QCowL2Meta
* from @cow_start and @cow_end into one single write operation.
*/
QEMUIOVector *data_qiov;
+ size_t data_qiov_offset;
/** Pointer to next L2Meta of the same write request */
struct QCowL2Meta *next;
diff --git a/include/qemu/iov.h b/include/qemu/iov.h
index 29957c8a72..bffc151282 100644
--- a/include/qemu/iov.h
+++ b/include/qemu/iov.h
@@ -206,6 +206,7 @@ void qemu_iovec_init_extended(
void *tail_buf, size_t tail_len);
void qemu_iovec_init_slice(QEMUIOVector *qiov, QEMUIOVector *source,
size_t offset, size_t len);
+int qemu_iovec_subvec_niov(QEMUIOVector *qiov, size_t offset, size_t len);
void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len);
void qemu_iovec_concat(QEMUIOVector *dst,
QEMUIOVector *src, size_t soffset, size_t sbytes);
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 0e4524d450..f09cc992af 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -829,7 +829,6 @@ static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
assert(start->nb_bytes <= UINT_MAX - end->nb_bytes);
assert(start->nb_bytes + end->nb_bytes <= UINT_MAX - data_bytes);
assert(start->offset + start->nb_bytes <= end->offset);
- assert(!m->data_qiov || m->data_qiov->size == data_bytes);
if ((start->nb_bytes == 0 && end->nb_bytes == 0) || m->skip_cow) {
return 0;
@@ -861,7 +860,11 @@ static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
/* The part of the buffer where the end region is located */
end_buffer = start_buffer + buffer_size - end->nb_bytes;
- qemu_iovec_init(&qiov, 2 + (m->data_qiov ? m->data_qiov->niov : 0));
+ qemu_iovec_init(&qiov, 2 + (m->data_qiov ?
+ qemu_iovec_subvec_niov(m->data_qiov,
+ m->data_qiov_offset,
+ data_bytes)
+ : 0));
qemu_co_mutex_unlock(&s->lock);
/* First we read the existing data from both COW regions. We
@@ -904,7 +907,7 @@ static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
if (start->nb_bytes) {
qemu_iovec_add(&qiov, start_buffer, start->nb_bytes);
}
- qemu_iovec_concat(&qiov, m->data_qiov, 0, data_bytes);
+ qemu_iovec_concat(&qiov, m->data_qiov, m->data_qiov_offset, data_bytes);
if (end->nb_bytes) {
qemu_iovec_add(&qiov, end_buffer, end->nb_bytes);
}
diff --git a/block/qcow2.c b/block/qcow2.c
index ec1fff9dd1..0882ff6e92 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2103,7 +2103,8 @@ fail:
/* Check if it's possible to merge a write request with the writing of
* the data from the COW regions */
static bool merge_cow(uint64_t offset, unsigned bytes,
- QEMUIOVector *hd_qiov, QCowL2Meta *l2meta)
+ QEMUIOVector *qiov, size_t qiov_offset,
+ QCowL2Meta *l2meta)
{
QCowL2Meta *m;
@@ -2132,11 +2133,12 @@ static bool merge_cow(uint64_t offset, unsigned bytes,
/* Make sure that adding both COW regions to the QEMUIOVector
* does not exceed IOV_MAX */
- if (hd_qiov->niov > IOV_MAX - 2) {
+ if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) {
continue;
}
- m->data_qiov = hd_qiov;
+ m->data_qiov = qiov;
+ m->data_qiov_offset = qiov_offset;
return true;
}
@@ -2218,24 +2220,22 @@ static int handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta)
return 0;
}
-static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
- uint64_t bytes, QEMUIOVector *qiov,
- int flags)
+static coroutine_fn int qcow2_co_pwritev_part(
+ BlockDriverState *bs, uint64_t offset, uint64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, int flags)
{
BDRVQcow2State *s = bs->opaque;
int offset_in_cluster;
int ret;
unsigned int cur_bytes; /* number of sectors in current iteration */
uint64_t cluster_offset;
- QEMUIOVector hd_qiov;
+ QEMUIOVector encrypted_qiov;
uint64_t bytes_done = 0;
uint8_t *cluster_data = NULL;
QCowL2Meta *l2meta = NULL;
trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes);
- qemu_iovec_init(&hd_qiov, qiov->niov);
-
qemu_co_mutex_lock(&s->lock);
while (bytes != 0) {
@@ -2268,9 +2268,6 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
qemu_co_mutex_unlock(&s->lock);
- qemu_iovec_reset(&hd_qiov);
- qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes);
-
if (bs->encrypted) {
assert(s->crypto);
if (!cluster_data) {
@@ -2283,9 +2280,9 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
}
}
- assert(hd_qiov.size <=
- QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
- qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
+ assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
+ qemu_iovec_to_buf(qiov, qiov_offset + bytes_done,
+ cluster_data, cur_bytes);
if (qcow2_co_encrypt(bs, cluster_offset, offset,
cluster_data, cur_bytes) < 0) {
@@ -2293,8 +2290,7 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
goto out_unlocked;
}
- qemu_iovec_reset(&hd_qiov);
- qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes);
+ qemu_iovec_init_buf(&encrypted_qiov, cluster_data, cur_bytes);
}
/* Try to efficiently initialize the physical space with zeroes */
@@ -2307,13 +2303,17 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
* writing of the guest data together with that of the COW regions.
* If it's not possible (or not necessary) then write the
* guest data now. */
- if (!merge_cow(offset, cur_bytes, &hd_qiov, l2meta)) {
+ if (!merge_cow(offset, cur_bytes,
+ bs->encrypted ? &encrypted_qiov : qiov,
+ bs->encrypted ? 0 : qiov_offset + bytes_done, l2meta))
+ {
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
trace_qcow2_writev_data(qemu_coroutine_self(),
cluster_offset + offset_in_cluster);
- ret = bdrv_co_pwritev(s->data_file,
- cluster_offset + offset_in_cluster,
- cur_bytes, &hd_qiov, 0);
+ ret = bdrv_co_pwritev_part(
+ s->data_file, cluster_offset + offset_in_cluster, cur_bytes,
+ bs->encrypted ? &encrypted_qiov : qiov,
+ bs->encrypted ? 0 : qiov_offset + bytes_done, 0);
if (ret < 0) {
goto out_unlocked;
}
@@ -2342,7 +2342,6 @@ out_locked:
qemu_co_mutex_unlock(&s->lock);
- qemu_iovec_destroy(&hd_qiov);
qemu_vfree(cluster_data);
trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
@@ -4007,8 +4006,9 @@ fail:
/* XXX: put compressed sectors first, then all the cluster aligned
tables to avoid losing bytes in alignment */
static coroutine_fn int
-qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
- uint64_t bytes, QEMUIOVector *qiov)
+qcow2_co_pwritev_compressed_part(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset)
{
BDRVQcow2State *s = bs->opaque;
int ret;
@@ -4045,7 +4045,7 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
/* Zero-pad last write if image size is not cluster aligned */
memset(buf + bytes, 0, s->cluster_size - bytes);
}
- qemu_iovec_to_buf(qiov, 0, buf, bytes);
+ qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes);
out_buf = g_malloc(s->cluster_size);
@@ -4053,7 +4053,7 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
buf, s->cluster_size);
if (out_len == -ENOMEM) {
/* could not compress: write normal cluster */
- ret = qcow2_co_pwritev(bs, offset, bytes, qiov, 0);
+ ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0);
if (ret < 0) {
goto fail;
}
@@ -4664,8 +4664,8 @@ static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
BDRVQcow2State *s = bs->opaque;
BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
- return bs->drv->bdrv_co_pwritev(bs, qcow2_vm_state_offset(s) + pos,
- qiov->size, qiov, 0);
+ return bs->drv->bdrv_co_pwritev_part(bs, qcow2_vm_state_offset(s) + pos,
+ qiov->size, qiov, 0, 0);
}
static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
@@ -5218,7 +5218,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_co_block_status = qcow2_co_block_status,
.bdrv_co_preadv_part = qcow2_co_preadv_part,
- .bdrv_co_pwritev = qcow2_co_pwritev,
+ .bdrv_co_pwritev_part = qcow2_co_pwritev_part,
.bdrv_co_flush_to_os = qcow2_co_flush_to_os,
.bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
@@ -5226,7 +5226,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_co_copy_range_from = qcow2_co_copy_range_from,
.bdrv_co_copy_range_to = qcow2_co_copy_range_to,
.bdrv_co_truncate = qcow2_co_truncate,
- .bdrv_co_pwritev_compressed = qcow2_co_pwritev_compressed,
+ .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part,
.bdrv_make_empty = qcow2_make_empty,
.bdrv_snapshot_create = qcow2_snapshot_create,
diff --git a/util/iov.c b/util/iov.c
index 9ac0261853..5059e10431 100644
--- a/util/iov.c
+++ b/util/iov.c
@@ -401,6 +401,16 @@ static struct iovec *qiov_slice(QEMUIOVector *qiov,
return iov;
}
+int qemu_iovec_subvec_niov(QEMUIOVector *qiov, size_t offset, size_t len)
+{
+ size_t head, tail;
+ int niov;
+
+ qiov_slice(qiov, offset, len, &head, &tail, &niov);
+
+ return niov;
+}
+
/*
* Compile new iovec, combining @head_buf buffer, sub-qiov of @mid_qiov,
* and @tail_buf buffer into new qiov.
--
2.21.0
^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [Qemu-devel] [PULL 00/12] Block patches
2019-08-27 20:16 [Qemu-devel] [PULL 00/12] Block patches Stefan Hajnoczi
` (11 preceding siblings ...)
2019-08-27 20:16 ` [Qemu-devel] [PULL 12/12] block/qcow2: implement .bdrv_co_pwritev(_compressed)_part Stefan Hajnoczi
@ 2019-09-03 10:05 ` Peter Maydell
12 siblings, 0 replies; 16+ messages in thread
From: Peter Maydell @ 2019-09-03 10:05 UTC (permalink / raw)
To: Stefan Hajnoczi
Cc: Fam Zheng, Kevin Wolf, Qemu-block, QEMU Developers, Max Reitz, John Snow
On Tue, 27 Aug 2019 at 21:16, Stefan Hajnoczi <stefanha@redhat.com> wrote:
>
> The following changes since commit dac03af5d5482ec7ee9c23db467bb7230b33c0d9:
>
> Merge remote-tracking branch 'remotes/rth/tags/pull-axp-20190825' into staging (2019-08-27 10:00:51 +0100)
>
> are available in the Git repository at:
>
> https://github.com/stefanha/qemu.git tags/block-pull-request
>
> for you to fetch changes up to 5396234b96a2ac743f48644529771498e036e698:
>
> block/qcow2: implement .bdrv_co_pwritev(_compressed)_part (2019-08-27 14:58:42 +0100)
>
> ----------------------------------------------------------------
> Pull request
Applied, thanks.
Please update the changelog at https://wiki.qemu.org/ChangeLog/4.2
for any user-visible changes.
-- PMM
^ permalink raw reply [flat|nested] 16+ messages in thread