* [Qemu-devel] [PATCH for-2.6 0/2] block: Fix blk_aio_write_zeroes()
@ 2016-04-13 11:06 Kevin Wolf
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z' Kevin Wolf
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 2/2] block: Fix blk_aio_write_zeroes() Kevin Wolf
0 siblings, 2 replies; 8+ messages in thread
From: Kevin Wolf @ 2016-04-13 11:06 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, qemu-devel
Kevin Wolf (2):
qemu-io: Support 'aio_write -z'
block: Fix blk_aio_write_zeroes()
block/block-backend.c | 20 +++++++----
qemu-io-cmds.c | 64 +++++++++++++++++++++++++++---------
tests/qemu-iotests/033 | 8 +++--
tests/qemu-iotests/033.out | 82 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 148 insertions(+), 26 deletions(-)
--
1.8.3.1
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z'
2016-04-13 11:06 [Qemu-devel] [PATCH for-2.6 0/2] block: Fix blk_aio_write_zeroes() Kevin Wolf
@ 2016-04-13 11:06 ` Kevin Wolf
2016-04-14 23:14 ` [Qemu-devel] [Qemu-block] " Max Reitz
2016-04-14 23:24 ` Max Reitz
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 2/2] block: Fix blk_aio_write_zeroes() Kevin Wolf
1 sibling, 2 replies; 8+ messages in thread
From: Kevin Wolf @ 2016-04-13 11:06 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, qemu-devel
This allows testing blk_aio_write_zeroes().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
qemu-io-cmds.c | 64 +++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 48 insertions(+), 16 deletions(-)
diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 382faa8..51ae5a5 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -1416,6 +1416,7 @@ struct aio_ctx {
int vflag;
int Cflag;
int Pflag;
+ int zflag;
BlockAcctCookie acct;
int pattern;
struct timeval t1;
@@ -1446,8 +1447,10 @@ static void aio_write_done(void *opaque, int ret)
print_report("wrote", &t2, ctx->offset, ctx->qiov.size,
ctx->qiov.size, 1, ctx->Cflag);
out:
- qemu_io_free(ctx->buf);
- qemu_iovec_destroy(&ctx->qiov);
+ if (!ctx->zflag) {
+ qemu_io_free(ctx->buf);
+ qemu_iovec_destroy(&ctx->qiov);
+ }
g_free(ctx);
}
@@ -1612,6 +1615,7 @@ static void aio_write_help(void)
" -P, -- use different pattern to fill file\n"
" -C, -- report statistics in a machine parsable format\n"
" -q, -- quiet mode, do not show I/O statistics\n"
+" -z, -- write zeroes using blk_aio_write_zeroes\n"
"\n");
}
@@ -1622,7 +1626,7 @@ static const cmdinfo_t aio_write_cmd = {
.cfunc = aio_write_f,
.argmin = 2,
.argmax = -1,
- .args = "[-Cq] [-P pattern ] off len [len..]",
+ .args = "[-Cqz] [-P pattern ] off len [len..]",
.oneline = "asynchronously writes a number of bytes",
.help = aio_write_help,
};
@@ -1634,7 +1638,7 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
struct aio_ctx *ctx = g_new0(struct aio_ctx, 1);
ctx->blk = blk;
- while ((c = getopt(argc, argv, "CqP:")) != -1) {
+ while ((c = getopt(argc, argv, "CqP:z")) != -1) {
switch (c) {
case 'C':
ctx->Cflag = 1;
@@ -1649,6 +1653,9 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
return 0;
}
break;
+ case 'z':
+ ctx->zflag = 1;
+ break;
default:
g_free(ctx);
return qemuio_command_usage(&aio_write_cmd);
@@ -1660,6 +1667,18 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
return qemuio_command_usage(&aio_write_cmd);
}
+ if (ctx->zflag && optind != argc - 2) {
+ printf("-z supports only a single length parameter\n");
+ g_free(ctx);
+ return 0;
+ }
+
+ if (ctx->zflag && ctx->Pflag) {
+ printf("-z and -P cannot be specified at the same time\n");
+ g_free(ctx);
+ return 0;
+ }
+
ctx->offset = cvtnum(argv[optind]);
if (ctx->offset < 0) {
print_cvtnum_err(ctx->offset, argv[optind]);
@@ -1676,19 +1695,32 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
return 0;
}
- nr_iov = argc - optind;
- ctx->buf = create_iovec(blk, &ctx->qiov, &argv[optind], nr_iov, pattern);
- if (ctx->buf == NULL) {
- block_acct_invalid(blk_get_stats(blk), BLOCK_ACCT_WRITE);
- g_free(ctx);
- return 0;
- }
+ if (ctx->zflag) {
+ int64_t count = cvtnum(argv[optind]);
+ if (count < 0) {
+ print_cvtnum_err(count, argv[optind]);
+ return 0;
+ }
- gettimeofday(&ctx->t1, NULL);
- block_acct_start(blk_get_stats(blk), &ctx->acct, ctx->qiov.size,
- BLOCK_ACCT_WRITE);
- blk_aio_writev(blk, ctx->offset >> 9, &ctx->qiov,
- ctx->qiov.size >> 9, aio_write_done, ctx);
+ ctx->qiov.size = count;
+ blk_aio_write_zeroes(blk, ctx->offset >> 9, count >> 9, 0,
+ aio_write_done, ctx);
+ } else {
+ nr_iov = argc - optind;
+ ctx->buf = create_iovec(blk, &ctx->qiov, &argv[optind], nr_iov, pattern);
+ if (ctx->buf == NULL) {
+ block_acct_invalid(blk_get_stats(blk), BLOCK_ACCT_WRITE);
+ g_free(ctx);
+ return 0;
+ }
+
+ gettimeofday(&ctx->t1, NULL);
+ block_acct_start(blk_get_stats(blk), &ctx->acct, ctx->qiov.size,
+ BLOCK_ACCT_WRITE);
+
+ blk_aio_writev(blk, ctx->offset >> 9, &ctx->qiov,
+ ctx->qiov.size >> 9, aio_write_done, ctx);
+ }
return 0;
}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH for-2.6 2/2] block: Fix blk_aio_write_zeroes()
2016-04-13 11:06 [Qemu-devel] [PATCH for-2.6 0/2] block: Fix blk_aio_write_zeroes() Kevin Wolf
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z' Kevin Wolf
@ 2016-04-13 11:06 ` Kevin Wolf
2016-04-14 23:30 ` [Qemu-devel] [Qemu-block] " Max Reitz
1 sibling, 1 reply; 8+ messages in thread
From: Kevin Wolf @ 2016-04-13 11:06 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, qemu-devel
Commit 57d6a428 broke blk_aio_write_zeroes() because in some write
functions in the call path don't have an explicit length argument but
reuse qiov->size instead. Which is great, except that write_zeroes
doesn't have a qiov, which this commit interprets as 0 bytes.
Consequently, blk_aio_write_zeroes() didn't effectively do anything.
This patch introduces an explicit acb->bytes in BlkAioEmAIOCB and uses
that instead of acb->rwco.size.
The synchronous version of the function is okay because it does pass a
qiov (with the right size and a NULL pointer as its base).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block/block-backend.c | 20 +++++++----
tests/qemu-iotests/033 | 8 +++--
tests/qemu-iotests/033.out | 82 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 100 insertions(+), 10 deletions(-)
diff --git a/block/block-backend.c b/block/block-backend.c
index d74f670..140c3f7 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -852,6 +852,7 @@ BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
typedef struct BlkAioEmAIOCB {
BlockAIOCB common;
BlkRwCo rwco;
+ int bytes;
bool has_returned;
QEMUBH* bh;
} BlkAioEmAIOCB;
@@ -877,7 +878,7 @@ static void blk_aio_complete_bh(void *opaque)
blk_aio_complete(opaque);
}
-static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset,
+static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes,
QEMUIOVector *qiov, CoroutineEntry co_entry,
BdrvRequestFlags flags,
BlockCompletionFunc *cb, void *opaque)
@@ -893,6 +894,7 @@ static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset,
.flags = flags,
.ret = NOT_DONE,
};
+ acb->bytes = bytes;
acb->bh = NULL;
acb->has_returned = false;
@@ -913,7 +915,8 @@ static void blk_aio_read_entry(void *opaque)
BlkAioEmAIOCB *acb = opaque;
BlkRwCo *rwco = &acb->rwco;
- rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, rwco->qiov->size,
+ assert(rwco->qiov->size == acb->bytes);
+ rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, acb->bytes,
rwco->qiov, rwco->flags);
blk_aio_complete(acb);
}
@@ -923,8 +926,8 @@ static void blk_aio_write_entry(void *opaque)
BlkAioEmAIOCB *acb = opaque;
BlkRwCo *rwco = &acb->rwco;
- rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset,
- rwco->qiov ? rwco->qiov->size : 0,
+ assert(!rwco->qiov || rwco->qiov->size == acb->bytes);
+ rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, acb->bytes,
rwco->qiov, rwco->flags);
blk_aio_complete(acb);
}
@@ -937,7 +940,8 @@ BlockAIOCB *blk_aio_write_zeroes(BlockBackend *blk, int64_t sector_num,
return blk_abort_aio_request(blk, cb, opaque, -EINVAL);
}
- return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS, NULL,
+ return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS,
+ nb_sectors << BDRV_SECTOR_BITS, NULL,
blk_aio_write_entry, BDRV_REQ_ZERO_WRITE, cb, opaque);
}
@@ -994,7 +998,8 @@ BlockAIOCB *blk_aio_readv(BlockBackend *blk, int64_t sector_num,
return blk_abort_aio_request(blk, cb, opaque, -EINVAL);
}
- return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS, iov,
+ assert(nb_sectors << BDRV_SECTOR_BITS == iov->size);
+ return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS, iov->size, iov,
blk_aio_read_entry, 0, cb, opaque);
}
@@ -1006,7 +1011,8 @@ BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num,
return blk_abort_aio_request(blk, cb, opaque, -EINVAL);
}
- return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS, iov,
+ assert(nb_sectors << BDRV_SECTOR_BITS == iov->size);
+ return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS, iov->size, iov,
blk_aio_write_entry, 0, cb, opaque);
}
diff --git a/tests/qemu-iotests/033 b/tests/qemu-iotests/033
index a61d8ce..912373d 100755
--- a/tests/qemu-iotests/033
+++ b/tests/qemu-iotests/033
@@ -57,12 +57,13 @@ do_test()
} | $QEMU_IO
}
+for write_zero_cmd in "write -z" "aio_write -z"; do
for align in 512 4k; do
echo
echo "== preparing image =="
do_test $align "write -P 0xa 0x200 0x400" "$TEST_IMG" | _filter_qemu_io
do_test $align "write -P 0xa 0x20000 0x600" "$TEST_IMG" | _filter_qemu_io
- do_test $align "write -z 0x400 0x20000" "$TEST_IMG" | _filter_qemu_io
+ do_test $align "$write_zero_cmd 0x400 0x20000" "$TEST_IMG" | _filter_qemu_io
echo
echo "== verifying patterns (1) =="
@@ -73,7 +74,7 @@ for align in 512 4k; do
echo
echo "== rewriting zeroes =="
do_test $align "write -P 0xb 0x10000 0x10000" "$TEST_IMG" | _filter_qemu_io
- do_test $align "write -z 0x10000 0x10000" "$TEST_IMG" | _filter_qemu_io
+ do_test $align "$write_zero_cmd 0x10000 0x10000" "$TEST_IMG" | _filter_qemu_io
echo
echo "== verifying patterns (2) =="
@@ -82,7 +83,7 @@ for align in 512 4k; do
echo
echo "== rewriting unaligned zeroes =="
do_test $align "write -P 0xb 0x0 0x1000" "$TEST_IMG" | _filter_qemu_io
- do_test $align "write -z 0x200 0x200" "$TEST_IMG" | _filter_qemu_io
+ do_test $align "$write_zero_cmd 0x200 0x200" "$TEST_IMG" | _filter_qemu_io
echo
echo "== verifying patterns (3) =="
@@ -92,6 +93,7 @@ for align in 512 4k; do
echo
done
+done
# success, all done
echo "*** done"
diff --git a/tests/qemu-iotests/033.out b/tests/qemu-iotests/033.out
index c3d18aa..95929ef 100644
--- a/tests/qemu-iotests/033.out
+++ b/tests/qemu-iotests/033.out
@@ -82,4 +82,86 @@ read 512/512 bytes at offset 512
read 3072/3072 bytes at offset 1024
3 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== preparing image ==
+wrote 1024/1024 bytes at offset 512
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 1536/1536 bytes at offset 131072
+1.500 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying patterns (1) ==
+read 512/512 bytes at offset 512
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 132096
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== rewriting zeroes ==
+wrote 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying patterns (2) ==
+read 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== rewriting unaligned zeroes ==
+wrote 4096/4096 bytes at offset 0
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 512
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying patterns (3) ==
+read 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 512
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 3072/3072 bytes at offset 1024
+3 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+
+== preparing image ==
+wrote 1024/1024 bytes at offset 512
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 1536/1536 bytes at offset 131072
+1.500 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying patterns (1) ==
+read 512/512 bytes at offset 512
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 132096
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== rewriting zeroes ==
+wrote 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying patterns (2) ==
+read 131072/131072 bytes at offset 1024
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== rewriting unaligned zeroes ==
+wrote 4096/4096 bytes at offset 0
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 512
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying patterns (3) ==
+read 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 512
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 3072/3072 bytes at offset 1024
+3 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
*** done
--
1.8.3.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [Qemu-block] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z'
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z' Kevin Wolf
@ 2016-04-14 23:14 ` Max Reitz
2016-04-15 8:18 ` Kevin Wolf
2016-04-14 23:24 ` Max Reitz
1 sibling, 1 reply; 8+ messages in thread
From: Max Reitz @ 2016-04-14 23:14 UTC (permalink / raw)
To: Kevin Wolf, qemu-block; +Cc: qemu-devel
[-- Attachment #1.1: Type: text/plain, Size: 465 bytes --]
On 13.04.2016 13:06, Kevin Wolf wrote:
> This allows testing blk_aio_write_zeroes().
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
> qemu-io-cmds.c | 64 +++++++++++++++++++++++++++++++++++++++++++---------------
> 1 file changed, 48 insertions(+), 16 deletions(-)
Despite the continuing use of int instead of bool where the latter would
be appropriate and of "9" instead of "BDRV_SECTOR_BITS":
Reviewed-by: Max Reitz <mreitz@redhat.com>
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 473 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [Qemu-block] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z'
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z' Kevin Wolf
2016-04-14 23:14 ` [Qemu-devel] [Qemu-block] " Max Reitz
@ 2016-04-14 23:24 ` Max Reitz
1 sibling, 0 replies; 8+ messages in thread
From: Max Reitz @ 2016-04-14 23:24 UTC (permalink / raw)
To: Kevin Wolf, qemu-block; +Cc: qemu-devel
[-- Attachment #1.1: Type: text/plain, Size: 610 bytes --]
On 13.04.2016 13:06, Kevin Wolf wrote:
> This allows testing blk_aio_write_zeroes().
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
> qemu-io-cmds.c | 64 +++++++++++++++++++++++++++++++++++++++++++---------------
> 1 file changed, 48 insertions(+), 16 deletions(-)
>
> diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
> index 382faa8..51ae5a5 100644
> --- a/qemu-io-cmds.c
> +++ b/qemu-io-cmds.c
[...]
> + ctx->buf = create_iovec(blk, &ctx->qiov, &argv[optind], nr_iov, pattern);
I just noticed this line has over 80 characters. R-b stands provided
this is fixed.
Max
[-- Attachment #2: OpenPGP digital signature --]
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [Qemu-block] [PATCH for-2.6 2/2] block: Fix blk_aio_write_zeroes()
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 2/2] block: Fix blk_aio_write_zeroes() Kevin Wolf
@ 2016-04-14 23:30 ` Max Reitz
2016-04-15 8:34 ` Kevin Wolf
0 siblings, 1 reply; 8+ messages in thread
From: Max Reitz @ 2016-04-14 23:30 UTC (permalink / raw)
To: Kevin Wolf, qemu-block; +Cc: qemu-devel
[-- Attachment #1.1: Type: text/plain, Size: 2038 bytes --]
On 13.04.2016 13:06, Kevin Wolf wrote:
> Commit 57d6a428 broke blk_aio_write_zeroes() because in some write
> functions in the call path don't have an explicit length argument but
> reuse qiov->size instead. Which is great, except that write_zeroes
> doesn't have a qiov, which this commit interprets as 0 bytes.
> Consequently, blk_aio_write_zeroes() didn't effectively do anything.
You mean it has written null data? :-)
Alternative version: So it has written zero bytes? Works as intended, then.
>
> This patch introduces an explicit acb->bytes in BlkAioEmAIOCB and uses
> that instead of acb->rwco.size.
>
> The synchronous version of the function is okay because it does pass a
> qiov (with the right size and a NULL pointer as its base).
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
> block/block-backend.c | 20 +++++++----
> tests/qemu-iotests/033 | 8 +++--
> tests/qemu-iotests/033.out | 82 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 100 insertions(+), 10 deletions(-)
>
> diff --git a/block/block-backend.c b/block/block-backend.c
> index d74f670..140c3f7 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
[...]
> @@ -937,7 +940,8 @@ BlockAIOCB *blk_aio_write_zeroes(BlockBackend *blk, int64_t sector_num,
> return blk_abort_aio_request(blk, cb, opaque, -EINVAL);
> }
>
> - return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS, NULL,
> + return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS,
> + nb_sectors << BDRV_SECTOR_BITS, NULL,
> blk_aio_write_entry, BDRV_REQ_ZERO_WRITE, cb, opaque);
> }
Another thing about blk_aio_write_zeroes() that might need fixing is
that it completely ignores its flags parameter.
That can be done in a seperate patch, however (and is probably not
critical, as this currently just means that a potential REQ_MAY_UNMAP
from scsi-disk is ignored), so:
Reviewed-by: Max Reitz <mreitz@redhat.com>
[-- Attachment #2: OpenPGP digital signature --]
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [Qemu-block] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z'
2016-04-14 23:14 ` [Qemu-devel] [Qemu-block] " Max Reitz
@ 2016-04-15 8:18 ` Kevin Wolf
0 siblings, 0 replies; 8+ messages in thread
From: Kevin Wolf @ 2016-04-15 8:18 UTC (permalink / raw)
To: Max Reitz; +Cc: qemu-block, qemu-devel
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Am 15.04.2016 um 01:14 hat Max Reitz geschrieben:
> On 13.04.2016 13:06, Kevin Wolf wrote:
> > This allows testing blk_aio_write_zeroes().
> >
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> > qemu-io-cmds.c | 64 +++++++++++++++++++++++++++++++++++++++++++---------------
> > 1 file changed, 48 insertions(+), 16 deletions(-)
>
> Despite the continuing use of int instead of bool where the latter would
> be appropriate and of "9" instead of "BDRV_SECTOR_BITS":
I considered whether to use bool, but having a few ints and then a bool
for flags in the same struct would be inconsistent. We can have a
cleanup patch on top that changes all instances.
Same thing really with the explicit 9. I didn't even notice it, but this
is just copied code and changing it in one instance only would be
inconsistent.
Kevin
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [Qemu-block] [PATCH for-2.6 2/2] block: Fix blk_aio_write_zeroes()
2016-04-14 23:30 ` [Qemu-devel] [Qemu-block] " Max Reitz
@ 2016-04-15 8:34 ` Kevin Wolf
0 siblings, 0 replies; 8+ messages in thread
From: Kevin Wolf @ 2016-04-15 8:34 UTC (permalink / raw)
To: Max Reitz; +Cc: qemu-block, qemu-devel
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Am 15.04.2016 um 01:30 hat Max Reitz geschrieben:
> On 13.04.2016 13:06, Kevin Wolf wrote:
> > Commit 57d6a428 broke blk_aio_write_zeroes() because in some write
> > functions in the call path don't have an explicit length argument but
> > reuse qiov->size instead. Which is great, except that write_zeroes
> > doesn't have a qiov, which this commit interprets as 0 bytes.
> > Consequently, blk_aio_write_zeroes() didn't effectively do anything.
>
> You mean it has written null data? :-)
>
> Alternative version: So it has written zero bytes? Works as intended, then.
I consciously avoided the latter wording. ;-)
> > This patch introduces an explicit acb->bytes in BlkAioEmAIOCB and uses
> > that instead of acb->rwco.size.
> >
> > The synchronous version of the function is okay because it does pass a
> > qiov (with the right size and a NULL pointer as its base).
> >
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > @@ -937,7 +940,8 @@ BlockAIOCB *blk_aio_write_zeroes(BlockBackend *blk, int64_t sector_num,
> > return blk_abort_aio_request(blk, cb, opaque, -EINVAL);
> > }
> >
> > - return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS, NULL,
> > + return blk_aio_prwv(blk, sector_num << BDRV_SECTOR_BITS,
> > + nb_sectors << BDRV_SECTOR_BITS, NULL,
> > blk_aio_write_entry, BDRV_REQ_ZERO_WRITE, cb, opaque);
> > }
>
> Another thing about blk_aio_write_zeroes() that might need fixing is
> that it completely ignores its flags parameter.
>
> That can be done in a seperate patch, however (and is probably not
> critical, as this currently just means that a potential REQ_MAY_UNMAP
> from scsi-disk is ignored), so:
Oh dear... Commit 57d6a428 was not my best patch ever, and apparently
Stefan wasn't suspicious enough to catch the bugs. Maybe someone should
re-review the whole thing...
"just" ignoring REQ_MAY_UNMAP is a regression in discard support, so no,
that's not what I would call harmless. Definitely needs fixing for 2.6.
And we probably need more qtests checking such things.
Kevin
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^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2016-04-15 8:34 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-04-13 11:06 [Qemu-devel] [PATCH for-2.6 0/2] block: Fix blk_aio_write_zeroes() Kevin Wolf
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 1/2] qemu-io: Support 'aio_write -z' Kevin Wolf
2016-04-14 23:14 ` [Qemu-devel] [Qemu-block] " Max Reitz
2016-04-15 8:18 ` Kevin Wolf
2016-04-14 23:24 ` Max Reitz
2016-04-13 11:06 ` [Qemu-devel] [PATCH for-2.6 2/2] block: Fix blk_aio_write_zeroes() Kevin Wolf
2016-04-14 23:30 ` [Qemu-devel] [Qemu-block] " Max Reitz
2016-04-15 8:34 ` Kevin Wolf
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