* [Qemu-devel] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it
@ 2019-08-17 17:53 Nir Soffer
2019-08-20 19:27 ` [Qemu-devel] [Qemu-block] " John Snow
2019-08-20 19:50 ` [Qemu-devel] " Max Reitz
0 siblings, 2 replies; 5+ messages in thread
From: Nir Soffer @ 2019-08-17 17:53 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, qemu-devel, Max Reitz, Nir Soffer,
Stefan Hajnoczi
Replace instances of:
(n & (BDRV_SECTOR_SIZE - 1)) == 0)
With:
QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)
Which reveals the intent of the code better, and makes it easier to
locate the code checking alignment.
QEMU_IS_ALIGNED is implemented using %, which may be less efficient but
it is used only in assert() except one instance, so it should not
matter.
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
---
block/bochs.c | 4 ++--
block/cloop.c | 4 ++--
block/dmg.c | 4 ++--
block/io.c | 8 ++++----
block/qcow2.c | 4 ++--
block/vvfat.c | 8 ++++----
qemu-img.c | 2 +-
7 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/block/bochs.c b/block/bochs.c
index 962f18592d..32bb83b268 100644
--- a/block/bochs.c
+++ b/block/bochs.c
@@ -248,8 +248,8 @@ bochs_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector local_qiov;
int ret;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
qemu_iovec_init(&local_qiov, qiov->niov);
qemu_co_mutex_lock(&s->lock);
diff --git a/block/cloop.c b/block/cloop.c
index 384c9735bb..4de94876d4 100644
--- a/block/cloop.c
+++ b/block/cloop.c
@@ -253,8 +253,8 @@ cloop_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
int nb_sectors = bytes >> BDRV_SECTOR_BITS;
int ret, i;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
qemu_co_mutex_lock(&s->lock);
diff --git a/block/dmg.c b/block/dmg.c
index 45f6b28f17..4a045f2b3e 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -697,8 +697,8 @@ dmg_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
int nb_sectors = bytes >> BDRV_SECTOR_BITS;
int ret, i;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
qemu_co_mutex_lock(&s->lock);
diff --git a/block/io.c b/block/io.c
index 56bbf195bb..7508703ecd 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1080,8 +1080,8 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
sector_num = offset >> BDRV_SECTOR_BITS;
nb_sectors = bytes >> BDRV_SECTOR_BITS;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
assert(bytes <= BDRV_REQUEST_MAX_BYTES);
assert(drv->bdrv_co_readv);
@@ -1133,8 +1133,8 @@ static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
sector_num = offset >> BDRV_SECTOR_BITS;
nb_sectors = bytes >> BDRV_SECTOR_BITS;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
assert(bytes <= BDRV_REQUEST_MAX_BYTES);
assert(drv->bdrv_co_writev);
diff --git a/block/qcow2.c b/block/qcow2.c
index 59cff1d4cb..41cab70e1d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2072,8 +2072,8 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
}
if (bs->encrypted) {
assert(s->crypto);
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(cur_bytes, BDRV_SECTOR_SIZE));
if (qcow2_co_decrypt(bs, cluster_offset, offset,
cluster_data, cur_bytes) < 0) {
ret = -EIO;
diff --git a/block/vvfat.c b/block/vvfat.c
index f6c28805dd..019b8f1341 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1547,8 +1547,8 @@ vvfat_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
int nb_sectors = bytes >> BDRV_SECTOR_BITS;
void *buf;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
buf = g_try_malloc(bytes);
if (bytes && buf == NULL) {
@@ -3082,8 +3082,8 @@ vvfat_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
int nb_sectors = bytes >> BDRV_SECTOR_BITS;
void *buf;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
buf = g_try_malloc(bytes);
if (bytes && buf == NULL) {
diff --git a/qemu-img.c b/qemu-img.c
index c920e3564c..ca3af0c549 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2138,7 +2138,7 @@ static int img_convert(int argc, char **argv)
int64_t sval;
sval = cvtnum(optarg);
- if (sval < 0 || sval & (BDRV_SECTOR_SIZE - 1) ||
+ if (sval < 0 || !QEMU_IS_ALIGNED(sval, BDRV_SECTOR_SIZE) ||
sval / BDRV_SECTOR_SIZE > MAX_BUF_SECTORS) {
error_report("Invalid buffer size for sparse output specified. "
"Valid sizes are multiples of %llu up to %llu. Select "
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [Qemu-block] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it
2019-08-17 17:53 [Qemu-devel] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it Nir Soffer
@ 2019-08-20 19:27 ` John Snow
2019-08-20 20:28 ` Nir Soffer
2019-08-20 19:50 ` [Qemu-devel] " Max Reitz
1 sibling, 1 reply; 5+ messages in thread
From: John Snow @ 2019-08-20 19:27 UTC (permalink / raw)
To: Nir Soffer, qemu-block
Cc: Kevin Wolf, Fam Zheng, qemu-devel, Stefan Hajnoczi, Max Reitz
On 8/17/19 1:53 PM, Nir Soffer wrote:
> Replace instances of:
>
> (n & (BDRV_SECTOR_SIZE - 1)) == 0)
>
> With:
>
> QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)
>
Do you have a magical incantation you used to find these?
> Which reveals the intent of the code better, and makes it easier to
> locate the code checking alignment.
>
> QEMU_IS_ALIGNED is implemented using %, which may be less efficient but
> it is used only in assert() except one instance, so it should not
> matter.
>
There is virtually no way these aren't optimized by the compiler.
> Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Therefore:
Reviewed-by: John Snow <jsnow@redhat.com>
> ---
> block/bochs.c | 4 ++--
> block/cloop.c | 4 ++--
> block/dmg.c | 4 ++--
> block/io.c | 8 ++++----
> block/qcow2.c | 4 ++--
> block/vvfat.c | 8 ++++----
> qemu-img.c | 2 +-
> 7 files changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/block/bochs.c b/block/bochs.c
> index 962f18592d..32bb83b268 100644
> --- a/block/bochs.c
> +++ b/block/bochs.c
> @@ -248,8 +248,8 @@ bochs_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
> QEMUIOVector local_qiov;
> int ret;
>
> - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
>
> qemu_iovec_init(&local_qiov, qiov->niov);
> qemu_co_mutex_lock(&s->lock);
> diff --git a/block/cloop.c b/block/cloop.c
> index 384c9735bb..4de94876d4 100644
> --- a/block/cloop.c
> +++ b/block/cloop.c
> @@ -253,8 +253,8 @@ cloop_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
> int nb_sectors = bytes >> BDRV_SECTOR_BITS;
> int ret, i;
>
> - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
>
> qemu_co_mutex_lock(&s->lock);
>
> diff --git a/block/dmg.c b/block/dmg.c
> index 45f6b28f17..4a045f2b3e 100644
> --- a/block/dmg.c
> +++ b/block/dmg.c
> @@ -697,8 +697,8 @@ dmg_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
> int nb_sectors = bytes >> BDRV_SECTOR_BITS;
> int ret, i;
>
> - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
>
> qemu_co_mutex_lock(&s->lock);
>
> diff --git a/block/io.c b/block/io.c
> index 56bbf195bb..7508703ecd 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -1080,8 +1080,8 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
> sector_num = offset >> BDRV_SECTOR_BITS;
> nb_sectors = bytes >> BDRV_SECTOR_BITS;
>
> - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> assert(bytes <= BDRV_REQUEST_MAX_BYTES);
> assert(drv->bdrv_co_readv);
>
> @@ -1133,8 +1133,8 @@ static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
> sector_num = offset >> BDRV_SECTOR_BITS;
> nb_sectors = bytes >> BDRV_SECTOR_BITS;
>
> - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> assert(bytes <= BDRV_REQUEST_MAX_BYTES);
>
> assert(drv->bdrv_co_writev);
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 59cff1d4cb..41cab70e1d 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -2072,8 +2072,8 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
> }
> if (bs->encrypted) {
> assert(s->crypto);
> - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> - assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> + assert(QEMU_IS_ALIGNED(cur_bytes, BDRV_SECTOR_SIZE));
> if (qcow2_co_decrypt(bs, cluster_offset, offset,
> cluster_data, cur_bytes) < 0) {
> ret = -EIO;
> diff --git a/block/vvfat.c b/block/vvfat.c
> index f6c28805dd..019b8f1341 100644
> --- a/block/vvfat.c
> +++ b/block/vvfat.c
> @@ -1547,8 +1547,8 @@ vvfat_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
> int nb_sectors = bytes >> BDRV_SECTOR_BITS;
> void *buf;
>
> - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
>
> buf = g_try_malloc(bytes);
> if (bytes && buf == NULL) {
> @@ -3082,8 +3082,8 @@ vvfat_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
> int nb_sectors = bytes >> BDRV_SECTOR_BITS;
> void *buf;
>
> - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
>
> buf = g_try_malloc(bytes);
> if (bytes && buf == NULL) {
> diff --git a/qemu-img.c b/qemu-img.c
> index c920e3564c..ca3af0c549 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -2138,7 +2138,7 @@ static int img_convert(int argc, char **argv)
> int64_t sval;
>
> sval = cvtnum(optarg);
> - if (sval < 0 || sval & (BDRV_SECTOR_SIZE - 1) ||
> + if (sval < 0 || !QEMU_IS_ALIGNED(sval, BDRV_SECTOR_SIZE) ||
> sval / BDRV_SECTOR_SIZE > MAX_BUF_SECTORS) {
> error_report("Invalid buffer size for sparse output specified. "
> "Valid sizes are multiples of %llu up to %llu. Select "
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [Qemu-block] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it
2019-08-20 19:27 ` [Qemu-devel] [Qemu-block] " John Snow
@ 2019-08-20 20:28 ` Nir Soffer
0 siblings, 0 replies; 5+ messages in thread
From: Nir Soffer @ 2019-08-20 20:28 UTC (permalink / raw)
To: John Snow
Cc: Kevin Wolf, Fam Zheng, Nir Soffer, qemu-block, QEMU Developers,
Max Reitz, Stefan Hajnoczi
On Tue, Aug 20, 2019 at 10:30 PM John Snow <jsnow@redhat.com> wrote:
>
>
> On 8/17/19 1:53 PM, Nir Soffer wrote:
> > Replace instances of:
> >
> > (n & (BDRV_SECTOR_SIZE - 1)) == 0)
> >
> > With:
> >
> > QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)
> >
>
> Do you have a magical incantation you used to find these?
>
I found the first by accident, then I used:
git grep 'BDRV_SECTOR_SIZE - 1'
> Which reveals the intent of the code better, and makes it easier to
> > locate the code checking alignment.
> >
> > QEMU_IS_ALIGNED is implemented using %, which may be less efficient but
> > it is used only in assert() except one instance, so it should not
> > matter.
> >
>
> There is virtually no way these aren't optimized by the compiler.
>
Makes sense, but I did not check.
>
> > Signed-off-by: Nir Soffer <nsoffer@redhat.com>
>
> Therefore:
>
> Reviewed-by: John Snow <jsnow@redhat.com>
>
> > ---
> > block/bochs.c | 4 ++--
> > block/cloop.c | 4 ++--
> > block/dmg.c | 4 ++--
> > block/io.c | 8 ++++----
> > block/qcow2.c | 4 ++--
> > block/vvfat.c | 8 ++++----
> > qemu-img.c | 2 +-
> > 7 files changed, 17 insertions(+), 17 deletions(-)
> >
> > diff --git a/block/bochs.c b/block/bochs.c
> > index 962f18592d..32bb83b268 100644
> > --- a/block/bochs.c
> > +++ b/block/bochs.c
> > @@ -248,8 +248,8 @@ bochs_co_preadv(BlockDriverState *bs, uint64_t
> offset, uint64_t bytes,
> > QEMUIOVector local_qiov;
> > int ret;
> >
> > - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> > - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> > + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> > + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> >
> > qemu_iovec_init(&local_qiov, qiov->niov);
> > qemu_co_mutex_lock(&s->lock);
> > diff --git a/block/cloop.c b/block/cloop.c
> > index 384c9735bb..4de94876d4 100644
> > --- a/block/cloop.c
> > +++ b/block/cloop.c
> > @@ -253,8 +253,8 @@ cloop_co_preadv(BlockDriverState *bs, uint64_t
> offset, uint64_t bytes,
> > int nb_sectors = bytes >> BDRV_SECTOR_BITS;
> > int ret, i;
> >
> > - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> > - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> > + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> > + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> >
> > qemu_co_mutex_lock(&s->lock);
> >
> > diff --git a/block/dmg.c b/block/dmg.c
> > index 45f6b28f17..4a045f2b3e 100644
> > --- a/block/dmg.c
> > +++ b/block/dmg.c
> > @@ -697,8 +697,8 @@ dmg_co_preadv(BlockDriverState *bs, uint64_t offset,
> uint64_t bytes,
> > int nb_sectors = bytes >> BDRV_SECTOR_BITS;
> > int ret, i;
> >
> > - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> > - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> > + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> > + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> >
> > qemu_co_mutex_lock(&s->lock);
> >
> > diff --git a/block/io.c b/block/io.c
> > index 56bbf195bb..7508703ecd 100644
> > --- a/block/io.c
> > +++ b/block/io.c
> > @@ -1080,8 +1080,8 @@ static int coroutine_fn
> bdrv_driver_preadv(BlockDriverState *bs,
> > sector_num = offset >> BDRV_SECTOR_BITS;
> > nb_sectors = bytes >> BDRV_SECTOR_BITS;
> >
> > - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> > - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> > + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> > + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> > assert(bytes <= BDRV_REQUEST_MAX_BYTES);
> > assert(drv->bdrv_co_readv);
> >
> > @@ -1133,8 +1133,8 @@ static int coroutine_fn
> bdrv_driver_pwritev(BlockDriverState *bs,
> > sector_num = offset >> BDRV_SECTOR_BITS;
> > nb_sectors = bytes >> BDRV_SECTOR_BITS;
> >
> > - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> > - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> > + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> > + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> > assert(bytes <= BDRV_REQUEST_MAX_BYTES);
> >
> > assert(drv->bdrv_co_writev);
> > diff --git a/block/qcow2.c b/block/qcow2.c
> > index 59cff1d4cb..41cab70e1d 100644
> > --- a/block/qcow2.c
> > +++ b/block/qcow2.c
> > @@ -2072,8 +2072,8 @@ static coroutine_fn int
> qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
> > }
> > if (bs->encrypted) {
> > assert(s->crypto);
> > - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> > - assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> > + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> > + assert(QEMU_IS_ALIGNED(cur_bytes, BDRV_SECTOR_SIZE));
> > if (qcow2_co_decrypt(bs, cluster_offset, offset,
> > cluster_data, cur_bytes) < 0) {
> > ret = -EIO;
> > diff --git a/block/vvfat.c b/block/vvfat.c
> > index f6c28805dd..019b8f1341 100644
> > --- a/block/vvfat.c
> > +++ b/block/vvfat.c
> > @@ -1547,8 +1547,8 @@ vvfat_co_preadv(BlockDriverState *bs, uint64_t
> offset, uint64_t bytes,
> > int nb_sectors = bytes >> BDRV_SECTOR_BITS;
> > void *buf;
> >
> > - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> > - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> > + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> > + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> >
> > buf = g_try_malloc(bytes);
> > if (bytes && buf == NULL) {
> > @@ -3082,8 +3082,8 @@ vvfat_co_pwritev(BlockDriverState *bs, uint64_t
> offset, uint64_t bytes,
> > int nb_sectors = bytes >> BDRV_SECTOR_BITS;
> > void *buf;
> >
> > - assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> > - assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> > + assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
> > + assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
> >
> > buf = g_try_malloc(bytes);
> > if (bytes && buf == NULL) {
> > diff --git a/qemu-img.c b/qemu-img.c
> > index c920e3564c..ca3af0c549 100644
> > --- a/qemu-img.c
> > +++ b/qemu-img.c
> > @@ -2138,7 +2138,7 @@ static int img_convert(int argc, char **argv)
> > int64_t sval;
> >
> > sval = cvtnum(optarg);
> > - if (sval < 0 || sval & (BDRV_SECTOR_SIZE - 1) ||
> > + if (sval < 0 || !QEMU_IS_ALIGNED(sval, BDRV_SECTOR_SIZE) ||
> > sval / BDRV_SECTOR_SIZE > MAX_BUF_SECTORS) {
> > error_report("Invalid buffer size for sparse output
> specified. "
> > "Valid sizes are multiples of %llu up to %llu.
> Select "
> >
>
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it
2019-08-17 17:53 [Qemu-devel] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it Nir Soffer
2019-08-20 19:27 ` [Qemu-devel] [Qemu-block] " John Snow
@ 2019-08-20 19:50 ` Max Reitz
2019-08-20 20:46 ` Nir Soffer
1 sibling, 1 reply; 5+ messages in thread
From: Max Reitz @ 2019-08-20 19:50 UTC (permalink / raw)
To: Nir Soffer, qemu-block
Cc: Kevin Wolf, Fam Zheng, Nir Soffer, qemu-devel, Stefan Hajnoczi
[-- Attachment #1.1: Type: text/plain, Size: 971 bytes --]
On 17.08.19 19:53, Nir Soffer wrote:
> Replace instances of:
>
> (n & (BDRV_SECTOR_SIZE - 1)) == 0)
>
> With:
>
> QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)
>
> Which reveals the intent of the code better, and makes it easier to
> locate the code checking alignment.
>
> QEMU_IS_ALIGNED is implemented using %, which may be less efficient but
> it is used only in assert() except one instance, so it should not
> matter.
>
> Signed-off-by: Nir Soffer <nsoffer@redhat.com>
> ---
> block/bochs.c | 4 ++--
> block/cloop.c | 4 ++--
> block/dmg.c | 4 ++--
> block/io.c | 8 ++++----
> block/qcow2.c | 4 ++--
> block/vvfat.c | 8 ++++----
> qemu-img.c | 2 +-
> 7 files changed, 17 insertions(+), 17 deletions(-)
Because John was speaking about a magical incantation, I found
BDRV_SECTOR_MASK. There are two places in block/qcow2-cluster.c that
use that to check alignment, I think those should be amended as well.
Max
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it
2019-08-20 19:50 ` [Qemu-devel] " Max Reitz
@ 2019-08-20 20:46 ` Nir Soffer
0 siblings, 0 replies; 5+ messages in thread
From: Nir Soffer @ 2019-08-20 20:46 UTC (permalink / raw)
To: Max Reitz
Cc: Kevin Wolf, Fam Zheng, Nir Soffer, qemu-block, QEMU Developers,
Stefan Hajnoczi
On Tue, Aug 20, 2019 at 10:51 PM Max Reitz <mreitz@redhat.com> wrote:
> On 17.08.19 19:53, Nir Soffer wrote:
> > Replace instances of:
> >
> > (n & (BDRV_SECTOR_SIZE - 1)) == 0)
> >
> > With:
> >
> > QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)
> >
> > Which reveals the intent of the code better, and makes it easier to
> > locate the code checking alignment.
> >
> > QEMU_IS_ALIGNED is implemented using %, which may be less efficient but
> > it is used only in assert() except one instance, so it should not
> > matter.
> >
> > Signed-off-by: Nir Soffer <nsoffer@redhat.com>
> > ---
> > block/bochs.c | 4 ++--
> > block/cloop.c | 4 ++--
> > block/dmg.c | 4 ++--
> > block/io.c | 8 ++++----
> > block/qcow2.c | 4 ++--
> > block/vvfat.c | 8 ++++----
> > qemu-img.c | 2 +-
> > 7 files changed, 17 insertions(+), 17 deletions(-)
>
> Because John was speaking about a magical incantation, I found
> BDRV_SECTOR_MASK. There are two places in block/qcow2-cluster.c that
> use that to check alignment, I think those should be amended as well.
>
$ git grep BDRV_SECTOR_MASK
block/qcow2-cluster.c: assert((offset_in_cluster &
~BDRV_SECTOR_MASK) == 0);
block/qcow2-cluster.c: assert((bytes & ~BDRV_SECTOR_MASK) == 0);
Right, should use QEMU_IS_ALIGNED
include/block/block.h:#define BDRV_SECTOR_MASK ~(BDRV_SECTOR_SIZE - 1)
include/block/block.h:#define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK
migration/block.c: flags = addr & ~BDRV_SECTOR_MASK;
This could use (BDRV_SECTOR_SIZE - 1).
In Linux SECTOR_MASK is defined as:
drivers/block/null_blk_main.c:#define SECTOR_MASK
(PAGE_SECTORS - 1)
It seems that qemu use use the same.
I will try to handle these in v2.
Nir
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-08-20 20:48 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-17 17:53 [Qemu-devel] [PATCH] block: Use QEMU_IS_ALIGNED instead of reinventing it Nir Soffer
2019-08-20 19:27 ` [Qemu-devel] [Qemu-block] " John Snow
2019-08-20 20:28 ` Nir Soffer
2019-08-20 19:50 ` [Qemu-devel] " Max Reitz
2019-08-20 20:46 ` Nir Soffer
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