* [Qemu-devel] [PATCH v5 01/20] block: Add .bdrv_co_block_status() callback
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 14:40 ` Kevin Wolf
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 02/20] block: Switch passthrough drivers to .bdrv_co_block_status() Eric Blake
` (18 subsequent siblings)
19 siblings, 1 reply; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Stefan Hajnoczi,
Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Now that the block layer exposes byte-based allocation,
it's time to tackle the drivers. Add a new callback that operates
on as small as byte boundaries. Subsequent patches will then update
individual drivers, then finally remove .bdrv_co_get_block_status().
The old code now uses a goto in order to minimize churn at that later
removal. Update documentation in this patch so that the later
removal can be a straight delete.
The new code also passes through the 'want_zero' hint, which will
allow subsequent patches to further optimize callers that only care
about how much of the image is allocated (want_zero is false),
rather than full details about runs of zeroes and which offsets the
allocation actually maps to (want_zero is true).
Note that most drivers give sector-aligned answers, except at
end-of-file, even when request_alignment is smaller than a sector.
However, bdrv_getlength() is sector-aligned (even though it gives a
byte answer), often by exceeding the actual file size. If we were to
give back strict results, at least file-posix.c would report a
transition from DATA to HOLE at the end of a file even in the middle
of a sector, which can throw off callers; so we intentionally lie and
state that any partial sector at the end of a file has the same
status for the entire sector. Maybe at some future day we can
report actual file size instead of rounding up, but not for this
series.
We also add an assertion that any driver using the new callback will
make progress (the only time pnum will be 0 is if the block layer
already handled an out-of-bounds request, or if there is an error).
Signed-off-by: Eric Blake <eblake@redhat.com>
---
v5: rebase to master, typo fix, document more block layer guarantees
v4: rebase to master
v3: no change
v2: improve alignment handling, ensure all iotests still pass
---
include/block/block.h | 9 ++++-----
include/block/block_int.h | 14 +++++++++++---
block/io.c | 31 ++++++++++++++++++++++++++-----
3 files changed, 41 insertions(+), 13 deletions(-)
diff --git a/include/block/block.h b/include/block/block.h
index c05cac57e5..798e98f783 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -136,11 +136,10 @@ typedef struct HDGeometry {
* that the block layer recompute the answer from the returned
* BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
*
- * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 (BDRV_BLOCK_OFFSET_MASK) of
- * the return value (old interface) or the entire map parameter (new
- * interface) represent the offset in the returned BDS that is allocated for
- * the corresponding raw data. However, whether that offset actually
- * contains data also depends on BDRV_BLOCK_DATA, as follows:
+ * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
+ * host offset within the returned BDS that is allocated for the
+ * corresponding raw guest data. However, whether that offset
+ * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
*
* DATA ZERO OFFSET_VALID
* t t t sectors read as zero, returned file is zero at offset
diff --git a/include/block/block_int.h b/include/block/block_int.h
index a5482775ec..071263c40f 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -206,13 +206,21 @@ struct BlockDriver {
* bdrv_is_allocated[_above]. The driver should answer only
* according to the current layer, and should not set
* BDRV_BLOCK_ALLOCATED, but may set BDRV_BLOCK_RAW. See block.h
- * for the meaning of _DATA, _ZERO, and _OFFSET_VALID. The block
- * layer guarantees input aligned to request_alignment, as well as
- * non-NULL pnum and file.
+ * for the meaning of _DATA, _ZERO, and _OFFSET_VALID. As a hint,
+ * the flag want_zero is true if the caller cares more about
+ * precise mappings (favor _OFFSET_VALID/_ZERO) or false for
+ * overall allocation (favor larger *pnum). The block layer
+ * guarantees input clamped to bdrv_getlength() and aligned to
+ * request_alignment, as well as non-NULL pnum, map, and file;
+ * in turn, the driver must return an error or set pnum to an
+ * aligned non-zero value.
*/
int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, int *pnum,
BlockDriverState **file);
+ int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs,
+ bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
+ int64_t *map, BlockDriverState **file);
/*
* Invalidate any cached meta-data.
diff --git a/block/io.c b/block/io.c
index 6773926fc1..5967f3a298 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1889,7 +1889,7 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
/* Must be non-NULL or bdrv_getlength() would have failed */
assert(bs->drv);
- if (!bs->drv->bdrv_co_get_block_status) {
+ if (!bs->drv->bdrv_co_get_block_status && !bs->drv->bdrv_co_block_status) {
*pnum = bytes;
ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
if (offset + bytes == total_size) {
@@ -1906,13 +1906,14 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
bdrv_inc_in_flight(bs);
/* Round out to request_alignment boundaries */
- /* TODO: until we have a byte-based driver callback, we also have to
- * round out to sectors, even if that is bigger than request_alignment */
- align = MAX(bs->bl.request_alignment, BDRV_SECTOR_SIZE);
+ align = bs->bl.request_alignment;
+ if (bs->drv->bdrv_co_get_block_status && align < BDRV_SECTOR_SIZE) {
+ align = BDRV_SECTOR_SIZE;
+ }
aligned_offset = QEMU_ALIGN_DOWN(offset, align);
aligned_bytes = ROUND_UP(offset + bytes, align) - aligned_offset;
- {
+ if (bs->drv->bdrv_co_get_block_status) {
int count; /* sectors */
int64_t longret;
@@ -1937,8 +1938,28 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
}
ret = longret & ~BDRV_BLOCK_OFFSET_MASK;
*pnum = count * BDRV_SECTOR_SIZE;
+ goto refine;
}
+ ret = bs->drv->bdrv_co_block_status(bs, want_zero, aligned_offset,
+ aligned_bytes, pnum, &local_map,
+ &local_file);
+ if (ret < 0) {
+ *pnum = 0;
+ goto out;
+ }
+ assert(*pnum); /* The block driver must make progress */
+
+ /*
+ * total_size is always sector-aligned, by sometimes exceeding actual
+ * file size. Expand pnum if it lands mid-sector due to end-of-file.
+ */
+ if (QEMU_ALIGN_UP(*pnum + aligned_offset,
+ BDRV_SECTOR_SIZE) == total_size) {
+ *pnum = total_size - aligned_offset;
+ }
+
+refine:
/*
* The driver's result must be a multiple of request_alignment.
* Clamp pnum and adjust map to original request.
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* Re: [Qemu-devel] [PATCH v5 01/20] block: Add .bdrv_co_block_status() callback
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 01/20] block: Add .bdrv_co_block_status() callback Eric Blake
@ 2017-12-01 14:40 ` Kevin Wolf
2017-12-01 15:03 ` Eric Blake
0 siblings, 1 reply; 26+ messages in thread
From: Kevin Wolf @ 2017-12-01 14:40 UTC (permalink / raw)
To: Eric Blake
Cc: qemu-devel, jsnow, famz, qemu-block, vsementsov, Stefan Hajnoczi,
Max Reitz
Am 01.12.2017 um 02:42 hat Eric Blake geschrieben:
> We are gradually moving away from sector-based interfaces, towards
> byte-based. Now that the block layer exposes byte-based allocation,
> it's time to tackle the drivers. Add a new callback that operates
> on as small as byte boundaries. Subsequent patches will then update
> individual drivers, then finally remove .bdrv_co_get_block_status().
> The old code now uses a goto in order to minimize churn at that later
> removal. Update documentation in this patch so that the later
> removal can be a straight delete.
>
> The new code also passes through the 'want_zero' hint, which will
> allow subsequent patches to further optimize callers that only care
> about how much of the image is allocated (want_zero is false),
> rather than full details about runs of zeroes and which offsets the
> allocation actually maps to (want_zero is true).
>
> Note that most drivers give sector-aligned answers, except at
> end-of-file, even when request_alignment is smaller than a sector.
> However, bdrv_getlength() is sector-aligned (even though it gives a
> byte answer), often by exceeding the actual file size. If we were to
> give back strict results, at least file-posix.c would report a
> transition from DATA to HOLE at the end of a file even in the middle
> of a sector, which can throw off callers; so we intentionally lie and
> state that any partial sector at the end of a file has the same
> status for the entire sector. Maybe at some future day we can
> report actual file size instead of rounding up, but not for this
> series.
In what way does this throw off callers in practice?
The rounding will lead to strange effects, and I'm not sure that dealing
with them is any easier than fixing the callers. Imagine an image file
like this (very small example, file size 384 bytes):
0 128 384 512
| | | |
+----+--------+----+
|Hole| Data | |
+----+--------+----+
|
EOF
bdrv_co_block_status(offset=0, bytes=512) returns 512 bytes of HOLE.
bdrv_co_block_status(offset=128, bytes=512) returns 384 bytes of DATA.
bdrv_co_block_status(offset=384, bytes=512) returns 128 bytes of HOLE.
This is not only contradictory, but the first one is almost begging for
data corruption because it returns HOLE for a region that actually
contains data.
The only excuse I can imagine is that we say that this can never happen
because drivers use 512 byte granularity anyway. But why are we
introducing the new interface then? I don't think this semantics is
compatible with a bytes-based driver interface.
> We also add an assertion that any driver using the new callback will
> make progress (the only time pnum will be 0 is if the block layer
> already handled an out-of-bounds request, or if there is an error).
>
> Signed-off-by: Eric Blake <eblake@redhat.com>
>
> ---
> v5: rebase to master, typo fix, document more block layer guarantees
> v4: rebase to master
> v3: no change
> v2: improve alignment handling, ensure all iotests still pass
> ---
> include/block/block.h | 9 ++++-----
> include/block/block_int.h | 14 +++++++++++---
> block/io.c | 31 ++++++++++++++++++++++++++-----
> 3 files changed, 41 insertions(+), 13 deletions(-)
>
> diff --git a/include/block/block.h b/include/block/block.h
> index c05cac57e5..798e98f783 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -136,11 +136,10 @@ typedef struct HDGeometry {
> * that the block layer recompute the answer from the returned
> * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
> *
> - * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 (BDRV_BLOCK_OFFSET_MASK) of
> - * the return value (old interface) or the entire map parameter (new
> - * interface) represent the offset in the returned BDS that is allocated for
> - * the corresponding raw data. However, whether that offset actually
> - * contains data also depends on BDRV_BLOCK_DATA, as follows:
> + * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
> + * host offset within the returned BDS that is allocated for the
> + * corresponding raw guest data. However, whether that offset
> + * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
> *
> * DATA ZERO OFFSET_VALID
> * t t t sectors read as zero, returned file is zero at offset
> diff --git a/include/block/block_int.h b/include/block/block_int.h
> index a5482775ec..071263c40f 100644
> --- a/include/block/block_int.h
> +++ b/include/block/block_int.h
> @@ -206,13 +206,21 @@ struct BlockDriver {
> * bdrv_is_allocated[_above]. The driver should answer only
> * according to the current layer, and should not set
> * BDRV_BLOCK_ALLOCATED, but may set BDRV_BLOCK_RAW. See block.h
> - * for the meaning of _DATA, _ZERO, and _OFFSET_VALID. The block
> - * layer guarantees input aligned to request_alignment, as well as
> - * non-NULL pnum and file.
> + * for the meaning of _DATA, _ZERO, and _OFFSET_VALID. As a hint,
> + * the flag want_zero is true if the caller cares more about
> + * precise mappings (favor _OFFSET_VALID/_ZERO) or false for
> + * overall allocation (favor larger *pnum). The block layer
> + * guarantees input clamped to bdrv_getlength() and aligned to
> + * request_alignment, as well as non-NULL pnum, map, and file;
> + * in turn, the driver must return an error or set pnum to an
> + * aligned non-zero value.
> */
> int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
> int64_t sector_num, int nb_sectors, int *pnum,
> BlockDriverState **file);
> + int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs,
> + bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
> + int64_t *map, BlockDriverState **file);
>
> /*
> * Invalidate any cached meta-data.
> diff --git a/block/io.c b/block/io.c
> index 6773926fc1..5967f3a298 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -1889,7 +1889,7 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
>
> /* Must be non-NULL or bdrv_getlength() would have failed */
> assert(bs->drv);
> - if (!bs->drv->bdrv_co_get_block_status) {
> + if (!bs->drv->bdrv_co_get_block_status && !bs->drv->bdrv_co_block_status) {
> *pnum = bytes;
> ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
> if (offset + bytes == total_size) {
> @@ -1906,13 +1906,14 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
> bdrv_inc_in_flight(bs);
>
> /* Round out to request_alignment boundaries */
> - /* TODO: until we have a byte-based driver callback, we also have to
> - * round out to sectors, even if that is bigger than request_alignment */
> - align = MAX(bs->bl.request_alignment, BDRV_SECTOR_SIZE);
> + align = bs->bl.request_alignment;
> + if (bs->drv->bdrv_co_get_block_status && align < BDRV_SECTOR_SIZE) {
> + align = BDRV_SECTOR_SIZE;
> + }
> aligned_offset = QEMU_ALIGN_DOWN(offset, align);
> aligned_bytes = ROUND_UP(offset + bytes, align) - aligned_offset;
>
> - {
> + if (bs->drv->bdrv_co_get_block_status) {
> int count; /* sectors */
> int64_t longret;
>
> @@ -1937,8 +1938,28 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
> }
> ret = longret & ~BDRV_BLOCK_OFFSET_MASK;
> *pnum = count * BDRV_SECTOR_SIZE;
> + goto refine;
> }
>
> + ret = bs->drv->bdrv_co_block_status(bs, want_zero, aligned_offset,
> + aligned_bytes, pnum, &local_map,
> + &local_file);
> + if (ret < 0) {
> + *pnum = 0;
> + goto out;
> + }
> + assert(*pnum); /* The block driver must make progress */
> +
> + /*
> + * total_size is always sector-aligned, by sometimes exceeding actual
> + * file size. Expand pnum if it lands mid-sector due to end-of-file.
> + */
> + if (QEMU_ALIGN_UP(*pnum + aligned_offset,
aligned_offset + *pnum wouldn be the more conventional order.
> + BDRV_SECTOR_SIZE) == total_size) {
> + *pnum = total_size - aligned_offset;
> + }
> +refine:
> /*
> * The driver's result must be a multiple of request_alignment.
> * Clamp pnum and adjust map to original request.
Kevin
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [Qemu-devel] [PATCH v5 01/20] block: Add .bdrv_co_block_status() callback
2017-12-01 14:40 ` Kevin Wolf
@ 2017-12-01 15:03 ` Eric Blake
2017-12-01 15:24 ` Kevin Wolf
0 siblings, 1 reply; 26+ messages in thread
From: Eric Blake @ 2017-12-01 15:03 UTC (permalink / raw)
To: Kevin Wolf
Cc: qemu-devel, jsnow, famz, qemu-block, vsementsov, Stefan Hajnoczi,
Max Reitz
On 12/01/2017 08:40 AM, Kevin Wolf wrote:
>> Note that most drivers give sector-aligned answers, except at
>> end-of-file, even when request_alignment is smaller than a sector.
>> However, bdrv_getlength() is sector-aligned (even though it gives a
>> byte answer), often by exceeding the actual file size. If we were to
>> give back strict results, at least file-posix.c would report a
>> transition from DATA to HOLE at the end of a file even in the middle
>> of a sector, which can throw off callers; so we intentionally lie and
>> state that any partial sector at the end of a file has the same
>> status for the entire sector. Maybe at some future day we can
>> report actual file size instead of rounding up, but not for this
>> series.
>
> In what way does this throw off callers in practice?
>
Several iotests failed if I didn't do that (it's been a few months, so
the details are a bit fuzzy). I think the biggest problem is that
because we round the size up in bdrv_getlength(), but CANNOT access
those rounded bytes, then reporting the status of those bytes as a hole
(which is the only sane thing that file-posix can do) can cause grief
when the rest of the sector (which we CAN access) is data.
> The rounding will lead to strange effects, and I'm not sure that dealing
> with them is any easier than fixing the callers. Imagine an image file
> like this (very small example, file size 384 bytes):
>
> 0 128 384 512
> | | | |
> +----+--------+----+
> |Hole| Data | |
> +----+--------+----+
> |
> EOF
Unlikely. Holes are at least a sector in size on all known filesystems
that have holes; that's also true for qcow2 format. The only
non-sector-aligned hole that you can encounter in practice is at EOF.
>
> bdrv_co_block_status(offset=0, bytes=512) returns 512 bytes of HOLE.
> bdrv_co_block_status(offset=128, bytes=512) returns 384 bytes of DATA.
> bdrv_co_block_status(offset=384, bytes=512) returns 128 bytes of HOLE.
>
> This is not only contradictory, but the first one is almost begging for
> data corruption because it returns HOLE for a region that actually
> contains data.
I agree that it would be confusing, if it were possible. But in
practice it is not possible.
>
> The only excuse I can imagine is that we say that this can never happen
> because drivers use 512 byte granularity anyway. But why are we
> introducing the new interface then? I don't think this semantics is
> compatible with a bytes-based driver interface.
Really, the ONLY boundary that is unlikely to ever be 512-byte aligned
is at EOF - and we wouldn't even need to do any rounding if
bdrv_getlength() didn't round.
One thing I _can_ do: it is ALWAYS valid to report a partial sector as
data. It may pessimize the code slightly, but while rounding the size of
a hole up can be wrong if the rounding covers data but the caller
getting the rounded data treats that data as 0, rounding the size of
data up will never misbehave because the caller will just read the
literal zeroes. So I will tweak the code to make sure that if any
rounding takes place, that either the driver already set BDRV_BLOCK_EOF
(all further bytes also read as zero), or else report the rounded region
as data. (I thought I could get away with only io.c setting
BDRV_BLOCK_EOF; but it sounds like setting it in the drivers will be
helpful).
>
>> We also add an assertion that any driver using the new callback will
>> make progress (the only time pnum will be 0 is if the block layer
>> already handled an out-of-bounds request, or if there is an error).
>>
>> Signed-off-by: Eric Blake <eblake@redhat.com>
>>
>> + ret = bs->drv->bdrv_co_block_status(bs, want_zero, aligned_offset,
>> + aligned_bytes, pnum, &local_map,
>> + &local_file);
>> + if (ret < 0) {
>> + *pnum = 0;
>> + goto out;
>> + }
>> + assert(*pnum); /* The block driver must make progress */
I debated about combining this assert...
>> +
>> + /*
>> + * total_size is always sector-aligned, by sometimes exceeding actual
>> + * file size. Expand pnum if it lands mid-sector due to end-of-file.
>> + */
>> + if (QEMU_ALIGN_UP(*pnum + aligned_offset,
>
> aligned_offset + *pnum wouldn be the more conventional order.
Sure.
>
>> + BDRV_SECTOR_SIZE) == total_size) {
>> + *pnum = total_size - aligned_offset;
>> + }
>> +refine:
>> /*
>> * The driver's result must be a multiple of request_alignment.
>> * Clamp pnum and adjust map to original request.
...with these, but it would trigger on at least vmdk (see patch 17/20)
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [Qemu-devel] [PATCH v5 01/20] block: Add .bdrv_co_block_status() callback
2017-12-01 15:03 ` Eric Blake
@ 2017-12-01 15:24 ` Kevin Wolf
2017-12-06 15:20 ` Eric Blake
0 siblings, 1 reply; 26+ messages in thread
From: Kevin Wolf @ 2017-12-01 15:24 UTC (permalink / raw)
To: Eric Blake
Cc: qemu-devel, jsnow, famz, qemu-block, vsementsov, Stefan Hajnoczi,
Max Reitz
Am 01.12.2017 um 16:03 hat Eric Blake geschrieben:
> On 12/01/2017 08:40 AM, Kevin Wolf wrote:
> > > Note that most drivers give sector-aligned answers, except at
> > > end-of-file, even when request_alignment is smaller than a sector.
> > > However, bdrv_getlength() is sector-aligned (even though it gives a
> > > byte answer), often by exceeding the actual file size. If we were to
> > > give back strict results, at least file-posix.c would report a
> > > transition from DATA to HOLE at the end of a file even in the middle
> > > of a sector, which can throw off callers; so we intentionally lie and
> > > state that any partial sector at the end of a file has the same
> > > status for the entire sector. Maybe at some future day we can
> > > report actual file size instead of rounding up, but not for this
> > > series.
> >
> > In what way does this throw off callers in practice?
>
> Several iotests failed if I didn't do that (it's been a few months, so the
> details are a bit fuzzy). I think the biggest problem is that because we
> round the size up in bdrv_getlength(), but CANNOT access those rounded
> bytes, then reporting the status of those bytes as a hole (which is the only
> sane thing that file-posix can do) can cause grief when the rest of the
> sector (which we CAN access) is data.
Does this indicate caller bugs? If they call byte-based
bdrv_co_block_status(), they should surely be able to handle this
situation in theory?
> > The rounding will lead to strange effects, and I'm not sure that dealing
> > with them is any easier than fixing the callers. Imagine an image file
> > like this (very small example, file size 384 bytes):
> >
> > 0 128 384 512
> > | | | |
> > +----+--------+----+
> > |Hole| Data | |
> > +----+--------+----+
> > |
> > EOF
>
> Unlikely. Holes are at least a sector in size on all known filesystems that
> have holes; that's also true for qcow2 format. The only non-sector-aligned
> hole that you can encounter in practice is at EOF.
Yes, probably not going to happen on file-posix. But I wouldn't bet
money that it's the same for all of the other protocols.
Wasn't one of the reasons for this series that NBD actually allows byte
granularity block status in its protocol? Which means that an NBD server
could expose something like this. Of course, in practice the server is
backed by something, too, so this situation is very unlikely, but
strictly speaking we wouldn't be able to work with all compliant
servers.
> > bdrv_co_block_status(offset=0, bytes=512) returns 512 bytes of HOLE.
> > bdrv_co_block_status(offset=128, bytes=512) returns 384 bytes of DATA.
> > bdrv_co_block_status(offset=384, bytes=512) returns 128 bytes of HOLE.
> >
> > This is not only contradictory, but the first one is almost begging for
> > data corruption because it returns HOLE for a region that actually
> > contains data.
>
> I agree that it would be confusing, if it were possible. But in practice it
> is not possible.
>
> >
> > The only excuse I can imagine is that we say that this can never happen
> > because drivers use 512 byte granularity anyway. But why are we
> > introducing the new interface then? I don't think this semantics is
> > compatible with a bytes-based driver interface.
>
> Really, the ONLY boundary that is unlikely to ever be 512-byte aligned is at
> EOF - and we wouldn't even need to do any rounding if bdrv_getlength()
> didn't round.
Yes, bdrv_getlength() needs to be converted sooner or later, too.
> One thing I _can_ do: it is ALWAYS valid to report a partial sector as data.
> It may pessimize the code slightly, but while rounding the size of a hole up
> can be wrong if the rounding covers data but the caller getting the rounded
> data treats that data as 0, rounding the size of data up will never
> misbehave because the caller will just read the literal zeroes. So I will
> tweak the code to make sure that if any rounding takes place, that either
> the driver already set BDRV_BLOCK_EOF (all further bytes also read as zero),
> or else report the rounded region as data. (I thought I could get away with
> only io.c setting BDRV_BLOCK_EOF; but it sounds like setting it in the
> drivers will be helpful).
This looks safer and definitely gives me a better feeling about the
rounding.
Kevin
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [Qemu-devel] [PATCH v5 01/20] block: Add .bdrv_co_block_status() callback
2017-12-01 15:24 ` Kevin Wolf
@ 2017-12-06 15:20 ` Eric Blake
0 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-06 15:20 UTC (permalink / raw)
To: Kevin Wolf
Cc: qemu-devel, jsnow, famz, qemu-block, vsementsov, Stefan Hajnoczi,
Max Reitz
[-- Attachment #1: Type: text/plain, Size: 2102 bytes --]
On 12/01/2017 09:24 AM, Kevin Wolf wrote:
> Am 01.12.2017 um 16:03 hat Eric Blake geschrieben:
>> On 12/01/2017 08:40 AM, Kevin Wolf wrote:
>>>> Note that most drivers give sector-aligned answers, except at
>>>> end-of-file, even when request_alignment is smaller than a sector.
>>>> However, bdrv_getlength() is sector-aligned (even though it gives a
>>>> byte answer), often by exceeding the actual file size. If we were to
>>>> give back strict results, at least file-posix.c would report a
>>>> transition from DATA to HOLE at the end of a file even in the middle
>>>> of a sector, which can throw off callers; so we intentionally lie and
>>>> state that any partial sector at the end of a file has the same
>>>> status for the entire sector. Maybe at some future day we can
>>>> report actual file size instead of rounding up, but not for this
>>>> series.
>>>
>>> In what way does this throw off callers in practice?
>>
>> Several iotests failed if I didn't do that (it's been a few months, so the
>> details are a bit fuzzy). I think the biggest problem is that because we
>> round the size up in bdrv_getlength(), but CANNOT access those rounded
>> bytes, then reporting the status of those bytes as a hole (which is the only
>> sane thing that file-posix can do) can cause grief when the rest of the
>> sector (which we CAN access) is data.
>
> Does this indicate caller bugs? If they call byte-based
> bdrv_co_block_status(), they should surely be able to handle this
> situation in theory?
Hmm, the more I try to reproduce the failure, the more I'm coming to the
conclusion that I needed this back when we returned a rounded offset via
the return value (my tag nbd-byte-callback-v2), but now that we return
the actual offset rather than a rounded offset via a secondary parameter
(my tag nbd-byte-callback-v4), we don't need to compensate for
end-of-file at all! That means even less code in my upcoming v5 submission.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 619 bytes --]
^ permalink raw reply [flat|nested] 26+ messages in thread
* [Qemu-devel] [PATCH v5 02/20] block: Switch passthrough drivers to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 01/20] block: Add .bdrv_co_block_status() callback Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 03/20] file-posix: Switch " Eric Blake
` (17 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz, Jeff Cody,
Stefan Hajnoczi
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the generic helpers, and all passthrough clients
(blkdebug, commit, mirror, throttle) accordingly.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: rebase to master
v4: rebase to interface tweak
v3: rebase to addition of throttle driver
v2: rebase to master, retitle while merging blkdebug, commit, and mirror
---
include/block/block_int.h | 28 ++++++++++++++++------------
block/io.c | 36 ++++++++++++++++++++----------------
block/blkdebug.c | 20 +++++++++++---------
block/commit.c | 2 +-
block/mirror.c | 2 +-
block/throttle.c | 2 +-
6 files changed, 50 insertions(+), 40 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 071263c40f..980333c671 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -1027,23 +1027,27 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
uint64_t *nperm, uint64_t *nshared);
/*
- * Default implementation for drivers to pass bdrv_co_get_block_status() to
+ * Default implementation for drivers to pass bdrv_co_block_status() to
* their file.
*/
-int64_t coroutine_fn bdrv_co_get_block_status_from_file(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors,
- int *pnum,
- BlockDriverState **file);
+int coroutine_fn bdrv_co_block_status_from_file(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset,
+ int64_t bytes,
+ int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file);
/*
- * Default implementation for drivers to pass bdrv_co_get_block_status() to
+ * Default implementation for drivers to pass bdrv_co_block_status() to
* their backing file.
*/
-int64_t coroutine_fn bdrv_co_get_block_status_from_backing(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors,
- int *pnum,
- BlockDriverState **file);
+int coroutine_fn bdrv_co_block_status_from_backing(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset,
+ int64_t bytes,
+ int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file);
const char *bdrv_get_parent_name(const BlockDriverState *bs);
void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp);
bool blk_dev_has_removable_media(BlockBackend *blk);
diff --git a/block/io.c b/block/io.c
index 5967f3a298..49d299b7e3 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1798,30 +1798,34 @@ typedef struct BdrvCoBlockStatusData {
bool done;
} BdrvCoBlockStatusData;
-int64_t coroutine_fn bdrv_co_get_block_status_from_file(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors,
- int *pnum,
- BlockDriverState **file)
+int coroutine_fn bdrv_co_block_status_from_file(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset,
+ int64_t bytes,
+ int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
{
assert(bs->file && bs->file->bs);
- *pnum = nb_sectors;
+ *pnum = bytes;
+ *map = offset;
*file = bs->file->bs;
- return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
- (sector_num << BDRV_SECTOR_BITS);
+ return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
}
-int64_t coroutine_fn bdrv_co_get_block_status_from_backing(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors,
- int *pnum,
- BlockDriverState **file)
+int coroutine_fn bdrv_co_block_status_from_backing(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset,
+ int64_t bytes,
+ int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
{
assert(bs->backing && bs->backing->bs);
- *pnum = nb_sectors;
+ *pnum = bytes;
+ *map = offset;
*file = bs->backing->bs;
- return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
- (sector_num << BDRV_SECTOR_BITS);
+ return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
}
/*
diff --git a/block/blkdebug.c b/block/blkdebug.c
index e21669979d..82c30357f8 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -627,15 +627,17 @@ static int coroutine_fn blkdebug_co_pdiscard(BlockDriverState *bs,
return bdrv_co_pdiscard(bs->file->bs, offset, bytes);
}
-static int64_t coroutine_fn blkdebug_co_get_block_status(
- BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum,
- BlockDriverState **file)
+static int coroutine_fn blkdebug_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset,
+ int64_t bytes,
+ int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
{
- assert(QEMU_IS_ALIGNED(sector_num | nb_sectors,
- DIV_ROUND_UP(bs->bl.request_alignment,
- BDRV_SECTOR_SIZE)));
- return bdrv_co_get_block_status_from_file(bs, sector_num, nb_sectors,
- pnum, file);
+ assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment));
+ return bdrv_co_block_status_from_file(bs, want_zero, offset, bytes,
+ pnum, map, file);
}
static void blkdebug_close(BlockDriverState *bs)
@@ -907,7 +909,7 @@ static BlockDriver bdrv_blkdebug = {
.bdrv_co_flush_to_disk = blkdebug_co_flush,
.bdrv_co_pwrite_zeroes = blkdebug_co_pwrite_zeroes,
.bdrv_co_pdiscard = blkdebug_co_pdiscard,
- .bdrv_co_get_block_status = blkdebug_co_get_block_status,
+ .bdrv_co_block_status = blkdebug_co_block_status,
.bdrv_debug_event = blkdebug_debug_event,
.bdrv_debug_breakpoint = blkdebug_debug_breakpoint,
diff --git a/block/commit.c b/block/commit.c
index c5327551ce..ae2a5ddba2 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -265,7 +265,7 @@ static void bdrv_commit_top_child_perm(BlockDriverState *bs, BdrvChild *c,
static BlockDriver bdrv_commit_top = {
.format_name = "commit_top",
.bdrv_co_preadv = bdrv_commit_top_preadv,
- .bdrv_co_get_block_status = bdrv_co_get_block_status_from_backing,
+ .bdrv_co_block_status = bdrv_co_block_status_from_backing,
.bdrv_refresh_filename = bdrv_commit_top_refresh_filename,
.bdrv_close = bdrv_commit_top_close,
.bdrv_child_perm = bdrv_commit_top_child_perm,
diff --git a/block/mirror.c b/block/mirror.c
index c9badc1203..f5bf620942 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1094,7 +1094,7 @@ static BlockDriver bdrv_mirror_top = {
.bdrv_co_pwrite_zeroes = bdrv_mirror_top_pwrite_zeroes,
.bdrv_co_pdiscard = bdrv_mirror_top_pdiscard,
.bdrv_co_flush = bdrv_mirror_top_flush,
- .bdrv_co_get_block_status = bdrv_co_get_block_status_from_backing,
+ .bdrv_co_block_status = bdrv_co_block_status_from_backing,
.bdrv_refresh_filename = bdrv_mirror_top_refresh_filename,
.bdrv_close = bdrv_mirror_top_close,
.bdrv_child_perm = bdrv_mirror_top_child_perm,
diff --git a/block/throttle.c b/block/throttle.c
index 833175ac77..d1324e7a9f 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -239,7 +239,7 @@ static BlockDriver bdrv_throttle = {
.bdrv_reopen_prepare = throttle_reopen_prepare,
.bdrv_reopen_commit = throttle_reopen_commit,
.bdrv_reopen_abort = throttle_reopen_abort,
- .bdrv_co_get_block_status = bdrv_co_get_block_status_from_file,
+ .bdrv_co_block_status = bdrv_co_block_status_from_file,
.bdrv_co_drain_begin = throttle_co_drain_begin,
.bdrv_co_drain_end = throttle_co_drain_end,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 03/20] file-posix: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 01/20] block: Add .bdrv_co_block_status() callback Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 02/20] block: Switch passthrough drivers to .bdrv_co_block_status() Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 16:00 ` Kevin Wolf
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 04/20] gluster: " Eric Blake
` (16 subsequent siblings)
19 siblings, 1 reply; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the file protocol driver accordingly.
In want_zero mode, we continue to report fine-grained hole
information (the caller wants as much mapping detail as possible);
but when not in that mode, the caller prefers larger *pnum and
merely cares about what offsets are allocated at this layer, rather
than where the holes live. Since holes still read as zeroes at
this layer (rather than deferring to a backing layer), we can take
the shortcut of skipping lseek(), and merely state that all bytes
are allocated.
We can also drop redundant bounds checks that are already
guaranteed by the block layer.
Signed-off-by: Eric Blake <eblake@redhat.com>
---
v5: drop redundant code
v4: tweak commit message [Fam], rebase to interface tweak
v3: no change
v2: tweak comment, add mapping support
---
block/file-posix.c | 62 +++++++++++++++++++++++++-----------------------------
1 file changed, 29 insertions(+), 33 deletions(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index 36ee89e940..e847c7cdd9 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2128,25 +2128,24 @@ static int find_allocation(BlockDriverState *bs, off_t start,
}
/*
- * Returns the allocation status of the specified sectors.
+ * Returns the allocation status of the specified offset.
*
- * If 'sector_num' is beyond the end of the disk image the return value is 0
- * and 'pnum' is set to 0.
+ * The block layer guarantees 'offset' and 'bytes' are within bounds.
*
- * 'pnum' is set to the number of sectors (including and immediately following
- * the specified sector) that are known to be in the same
+ * 'pnum' is set to the number of bytes (including and immediately following
+ * the specified offset) that are known to be in the same
* allocated/unallocated state.
*
- * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
- * beyond the end of the disk image it will be clamped.
+ * 'bytes' is the max value 'pnum' should be set to.
*/
-static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors, int *pnum,
- BlockDriverState **file)
+static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset,
+ int64_t bytes, int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
{
- off_t start, data = 0, hole = 0;
- int64_t total_size;
+ off_t data = 0, hole = 0;
int ret;
ret = fd_open(bs);
@@ -2154,39 +2153,36 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
return ret;
}
- start = sector_num * BDRV_SECTOR_SIZE;
- total_size = bdrv_getlength(bs);
- if (total_size < 0) {
- return total_size;
- } else if (start >= total_size) {
- *pnum = 0;
- return 0;
- } else if (start + nb_sectors * BDRV_SECTOR_SIZE > total_size) {
- nb_sectors = DIV_ROUND_UP(total_size - start, BDRV_SECTOR_SIZE);
+ if (!want_zero) {
+ *pnum = bytes;
+ *map = offset;
+ *file = bs;
+ return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
}
- ret = find_allocation(bs, start, &data, &hole);
+ ret = find_allocation(bs, offset, &data, &hole);
if (ret == -ENXIO) {
/* Trailing hole */
- *pnum = nb_sectors;
+ *pnum = bytes;
ret = BDRV_BLOCK_ZERO;
} else if (ret < 0) {
/* No info available, so pretend there are no holes */
- *pnum = nb_sectors;
+ *pnum = bytes;
ret = BDRV_BLOCK_DATA;
- } else if (data == start) {
- /* On a data extent, compute sectors to the end of the extent,
+ } else if (data == offset) {
+ /* On a data extent, compute bytes to the end of the extent,
* possibly including a partial sector at EOF. */
- *pnum = MIN(nb_sectors, DIV_ROUND_UP(hole - start, BDRV_SECTOR_SIZE));
+ *pnum = MIN(bytes, hole - offset);
ret = BDRV_BLOCK_DATA;
} else {
- /* On a hole, compute sectors to the beginning of the next extent. */
- assert(hole == start);
- *pnum = MIN(nb_sectors, (data - start) / BDRV_SECTOR_SIZE);
+ /* On a hole, compute bytes to the beginning of the next extent. */
+ assert(hole == offset);
+ *pnum = MIN(bytes, data - offset);
ret = BDRV_BLOCK_ZERO;
}
+ *map = offset;
*file = bs;
- return ret | BDRV_BLOCK_OFFSET_VALID | start;
+ return ret | BDRV_BLOCK_OFFSET_VALID;
}
static coroutine_fn BlockAIOCB *raw_aio_pdiscard(BlockDriverState *bs,
@@ -2280,7 +2276,7 @@ BlockDriver bdrv_file = {
.bdrv_close = raw_close,
.bdrv_create = raw_create,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
- .bdrv_co_get_block_status = raw_co_get_block_status,
+ .bdrv_co_block_status = raw_co_block_status,
.bdrv_co_pwrite_zeroes = raw_co_pwrite_zeroes,
.bdrv_co_preadv = raw_co_preadv,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* Re: [Qemu-devel] [PATCH v5 03/20] file-posix: Switch to .bdrv_co_block_status()
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 03/20] file-posix: Switch " Eric Blake
@ 2017-12-01 16:00 ` Kevin Wolf
0 siblings, 0 replies; 26+ messages in thread
From: Kevin Wolf @ 2017-12-01 16:00 UTC (permalink / raw)
To: Eric Blake; +Cc: qemu-devel, jsnow, famz, qemu-block, vsementsov, Max Reitz
Am 01.12.2017 um 02:42 hat Eric Blake geschrieben:
> We are gradually moving away from sector-based interfaces, towards
> byte-based. Update the file protocol driver accordingly.
>
> In want_zero mode, we continue to report fine-grained hole
> information (the caller wants as much mapping detail as possible);
> but when not in that mode, the caller prefers larger *pnum and
> merely cares about what offsets are allocated at this layer, rather
> than where the holes live. Since holes still read as zeroes at
> this layer (rather than deferring to a backing layer), we can take
> the shortcut of skipping lseek(), and merely state that all bytes
> are allocated.
>
> We can also drop redundant bounds checks that are already
> guaranteed by the block layer.
>
> Signed-off-by: Eric Blake <eblake@redhat.com>
>
> ---
> v5: drop redundant code
> v4: tweak commit message [Fam], rebase to interface tweak
> v3: no change
> v2: tweak comment, add mapping support
> ---
> block/file-posix.c | 62 +++++++++++++++++++++++++-----------------------------
> 1 file changed, 29 insertions(+), 33 deletions(-)
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 36ee89e940..e847c7cdd9 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -2128,25 +2128,24 @@ static int find_allocation(BlockDriverState *bs, off_t start,
> }
>
> /*
> - * Returns the allocation status of the specified sectors.
> + * Returns the allocation status of the specified offset.
> *
> - * If 'sector_num' is beyond the end of the disk image the return value is 0
> - * and 'pnum' is set to 0.
> + * The block layer guarantees 'offset' and 'bytes' are within bounds.
> *
> - * 'pnum' is set to the number of sectors (including and immediately following
> - * the specified sector) that are known to be in the same
> + * 'pnum' is set to the number of bytes (including and immediately following
> + * the specified offset) that are known to be in the same
> * allocated/unallocated state.
> *
> - * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
> - * beyond the end of the disk image it will be clamped.
> + * 'bytes' is the max value 'pnum' should be set to.
> */
> -static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
> - int64_t sector_num,
> - int nb_sectors, int *pnum,
> - BlockDriverState **file)
> +static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
> + bool want_zero,
> + int64_t offset,
> + int64_t bytes, int64_t *pnum,
> + int64_t *map,
> + BlockDriverState **file)
> {
> - off_t start, data = 0, hole = 0;
> - int64_t total_size;
> + off_t data = 0, hole = 0;
> int ret;
>
> ret = fd_open(bs);
> @@ -2154,39 +2153,36 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
> return ret;
> }
>
> - start = sector_num * BDRV_SECTOR_SIZE;
> - total_size = bdrv_getlength(bs);
> - if (total_size < 0) {
> - return total_size;
> - } else if (start >= total_size) {
> - *pnum = 0;
> - return 0;
> - } else if (start + nb_sectors * BDRV_SECTOR_SIZE > total_size) {
> - nb_sectors = DIV_ROUND_UP(total_size - start, BDRV_SECTOR_SIZE);
> + if (!want_zero) {
> + *pnum = bytes;
> + *map = offset;
> + *file = bs;
> + return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
> }
The documentation for want_zero in io.c is:
* If 'want_zero' is true, the caller is querying for mapping purposes,
* and the result should include BDRV_BLOCK_OFFSET_VALID and
* BDRV_BLOCK_ZERO where possible; otherwise, the result may omit those
* bits particularly if it allows for a larger value in 'pnum'.
Do we need to include BDRV_BLOCK_DATA there? Otherwise this shortcut
would be wrong because BDRV_BLOCK_DATA always needs to be exact, even for
want_zero = false.
At first I expected that we want bdrv_is_allocated() to indicate holes
in raw files, but that's already not true today, so I now think this is
a matter of tweaking the documentation rather than removing the
shortcut.
While I'm looking at documentation, commit e88ae2264 had this:
* BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
* layer (as opposed to the backing file)
With this semantics, always returning BDRV_BLOCK_ALLOCATED (and
therefore bdrv_is_allocated() == true) for raw file is correct. Your
recent commit 4c41cb4 changed it into:
* BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
* layer (short for DATA || ZERO), set by block layer
Its commit message also talks about doing this "for convenience". This
is not true. There are code paths that set ZERO after ALLOCATED has
already been decided. ALLOCATED was introduced to distinguish a ZERO
coming from the driver and a ZERO derived in io.c because the latter
doesn't tell us about the allocation status (see commit e88ae2264).
So this documentation should be tweaked as well (possibly just reverting
4c41cb4 for BDRV_BLOCK_ALLOCATED).
Kevin
^ permalink raw reply [flat|nested] 26+ messages in thread
* [Qemu-devel] [PATCH v5 04/20] gluster: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (2 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 03/20] file-posix: Switch " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 05/20] iscsi: Switch cluster_sectors to byte-based Eric Blake
` (15 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Jeff Cody, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the gluster driver accordingly.
In want_zero mode, we continue to report fine-grained hole
information (the caller wants as much mapping detail as possible);
but when not in that mode, the caller prefers larger *pnum and
merely cares about what offsets are allocated at this layer, rather
than where the holes live. Since holes still read as zeroes at
this layer (rather than deferring to a backing layer), we can take
the shortcut of skipping find_allocation(), and merely state that
all bytes are allocated.
We can also drop redundant bounds checks that are already
guaranteed by the block layer.
Signed-off-by: Eric Blake <eblake@redhat.com>
---
v5: drop redundant code
v4: tweak commit message [Fam], rebase to interface tweak
v3: no change
v2: tweak comments [Prasanna], add mapping, drop R-b
---
block/gluster.c | 70 ++++++++++++++++++++++++++++-----------------------------
1 file changed, 34 insertions(+), 36 deletions(-)
diff --git a/block/gluster.c b/block/gluster.c
index 0f4265a3a4..6388ced82e 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -1349,68 +1349,66 @@ exit:
}
/*
- * Returns the allocation status of the specified sectors.
+ * Returns the allocation status of the specified offset.
*
- * If 'sector_num' is beyond the end of the disk image the return value is 0
- * and 'pnum' is set to 0.
+ * The block layer guarantees 'offset' and 'bytes' are within bounds.
*
- * 'pnum' is set to the number of sectors (including and immediately following
- * the specified sector) that are known to be in the same
+ * 'pnum' is set to the number of bytes (including and immediately following
+ * the specified offset) that are known to be in the same
* allocated/unallocated state.
*
- * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
- * beyond the end of the disk image it will be clamped.
+ * 'bytes' is the max value 'pnum' should be set to.
*
- * (Based on raw_co_get_block_status() from file-posix.c.)
+ * (Based on raw_co_block_status() from file-posix.c.)
*/
-static int64_t coroutine_fn qemu_gluster_co_get_block_status(
- BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum,
- BlockDriverState **file)
+static int coroutine_fn qemu_gluster_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset,
+ int64_t bytes,
+ int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
{
BDRVGlusterState *s = bs->opaque;
- off_t start, data = 0, hole = 0;
- int64_t total_size;
+ off_t data = 0, hole = 0;
int ret = -EINVAL;
if (!s->fd) {
return ret;
}
- start = sector_num * BDRV_SECTOR_SIZE;
- total_size = bdrv_getlength(bs);
- if (total_size < 0) {
- return total_size;
- } else if (start >= total_size) {
- *pnum = 0;
- return 0;
- } else if (start + nb_sectors * BDRV_SECTOR_SIZE > total_size) {
- nb_sectors = DIV_ROUND_UP(total_size - start, BDRV_SECTOR_SIZE);
+ if (!want_zero) {
+ *pnum = bytes;
+ *map = offset;
+ *file = bs;
+ return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
}
- ret = find_allocation(bs, start, &data, &hole);
+ ret = find_allocation(bs, offset, &data, &hole);
if (ret == -ENXIO) {
/* Trailing hole */
- *pnum = nb_sectors;
+ *pnum = bytes;
ret = BDRV_BLOCK_ZERO;
} else if (ret < 0) {
/* No info available, so pretend there are no holes */
- *pnum = nb_sectors;
+ *pnum = bytes;
ret = BDRV_BLOCK_DATA;
- } else if (data == start) {
- /* On a data extent, compute sectors to the end of the extent,
+ } else if (data == offset) {
+ /* On a data extent, compute bytes to the end of the extent,
* possibly including a partial sector at EOF. */
- *pnum = MIN(nb_sectors, DIV_ROUND_UP(hole - start, BDRV_SECTOR_SIZE));
+ *pnum = MIN(bytes, hole - offset);
ret = BDRV_BLOCK_DATA;
} else {
- /* On a hole, compute sectors to the beginning of the next extent. */
- assert(hole == start);
- *pnum = MIN(nb_sectors, (data - start) / BDRV_SECTOR_SIZE);
+ /* On a hole, compute bytes to the beginning of the next extent. */
+ assert(hole == offset);
+ *pnum = MIN(bytes, data - offset);
ret = BDRV_BLOCK_ZERO;
}
+ *map = offset;
*file = bs;
- return ret | BDRV_BLOCK_OFFSET_VALID | start;
+ return ret | BDRV_BLOCK_OFFSET_VALID;
}
@@ -1438,7 +1436,7 @@ static BlockDriver bdrv_gluster = {
#ifdef CONFIG_GLUSTERFS_ZEROFILL
.bdrv_co_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes,
#endif
- .bdrv_co_get_block_status = qemu_gluster_co_get_block_status,
+ .bdrv_co_block_status = qemu_gluster_co_block_status,
.create_opts = &qemu_gluster_create_opts,
};
@@ -1466,7 +1464,7 @@ static BlockDriver bdrv_gluster_tcp = {
#ifdef CONFIG_GLUSTERFS_ZEROFILL
.bdrv_co_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes,
#endif
- .bdrv_co_get_block_status = qemu_gluster_co_get_block_status,
+ .bdrv_co_block_status = qemu_gluster_co_block_status,
.create_opts = &qemu_gluster_create_opts,
};
@@ -1494,7 +1492,7 @@ static BlockDriver bdrv_gluster_unix = {
#ifdef CONFIG_GLUSTERFS_ZEROFILL
.bdrv_co_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes,
#endif
- .bdrv_co_get_block_status = qemu_gluster_co_get_block_status,
+ .bdrv_co_block_status = qemu_gluster_co_block_status,
.create_opts = &qemu_gluster_create_opts,
};
@@ -1528,7 +1526,7 @@ static BlockDriver bdrv_gluster_rdma = {
#ifdef CONFIG_GLUSTERFS_ZEROFILL
.bdrv_co_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes,
#endif
- .bdrv_co_get_block_status = qemu_gluster_co_get_block_status,
+ .bdrv_co_block_status = qemu_gluster_co_block_status,
.create_opts = &qemu_gluster_create_opts,
};
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 05/20] iscsi: Switch cluster_sectors to byte-based
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (3 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 04/20] gluster: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 06/20] iscsi: Switch iscsi_allocmap_update() " Eric Blake
` (14 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Ronnie Sahlberg,
Paolo Bonzini, Peter Lieven, Max Reitz
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert all uses of
the cluster size in sectors, along with adding assertions that we
are not dividing by zero.
Improve some comment grammar while in the area.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
---
v2-v5: no change
---
block/iscsi.c | 56 +++++++++++++++++++++++++++++++++++---------------------
1 file changed, 35 insertions(+), 21 deletions(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index 4683f3b244..8f903d8370 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -84,7 +84,7 @@ typedef struct IscsiLun {
unsigned long *allocmap;
unsigned long *allocmap_valid;
long allocmap_size;
- int cluster_sectors;
+ int cluster_size;
bool use_16_for_rw;
bool write_protected;
bool lbpme;
@@ -427,9 +427,10 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags)
{
iscsi_allocmap_free(iscsilun);
+ assert(iscsilun->cluster_size);
iscsilun->allocmap_size =
- DIV_ROUND_UP(sector_lun2qemu(iscsilun->num_blocks, iscsilun),
- iscsilun->cluster_sectors);
+ DIV_ROUND_UP(iscsilun->num_blocks * iscsilun->block_size,
+ iscsilun->cluster_size);
iscsilun->allocmap = bitmap_try_new(iscsilun->allocmap_size);
if (!iscsilun->allocmap) {
@@ -437,7 +438,7 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags)
}
if (open_flags & BDRV_O_NOCACHE) {
- /* in case that cache.direct = on all allocmap entries are
+ /* when cache.direct = on all allocmap entries are
* treated as invalid to force a relookup of the block
* status on every read request */
return 0;
@@ -458,17 +459,19 @@ iscsi_allocmap_update(IscsiLun *iscsilun, int64_t sector_num,
int nb_sectors, bool allocated, bool valid)
{
int64_t cl_num_expanded, nb_cls_expanded, cl_num_shrunk, nb_cls_shrunk;
+ int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS;
if (iscsilun->allocmap == NULL) {
return;
}
/* expand to entirely contain all affected clusters */
- cl_num_expanded = sector_num / iscsilun->cluster_sectors;
+ assert(cluster_sectors);
+ cl_num_expanded = sector_num / cluster_sectors;
nb_cls_expanded = DIV_ROUND_UP(sector_num + nb_sectors,
- iscsilun->cluster_sectors) - cl_num_expanded;
+ cluster_sectors) - cl_num_expanded;
/* shrink to touch only completely contained clusters */
- cl_num_shrunk = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors);
- nb_cls_shrunk = (sector_num + nb_sectors) / iscsilun->cluster_sectors
+ cl_num_shrunk = DIV_ROUND_UP(sector_num, cluster_sectors);
+ nb_cls_shrunk = (sector_num + nb_sectors) / cluster_sectors
- cl_num_shrunk;
if (allocated) {
bitmap_set(iscsilun->allocmap, cl_num_expanded, nb_cls_expanded);
@@ -532,9 +535,12 @@ iscsi_allocmap_is_allocated(IscsiLun *iscsilun, int64_t sector_num,
if (iscsilun->allocmap == NULL) {
return true;
}
- size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
+ assert(iscsilun->cluster_size);
+ size = DIV_ROUND_UP(sector_num + nb_sectors,
+ iscsilun->cluster_size >> BDRV_SECTOR_BITS);
return !(find_next_bit(iscsilun->allocmap, size,
- sector_num / iscsilun->cluster_sectors) == size);
+ sector_num * BDRV_SECTOR_SIZE /
+ iscsilun->cluster_size) == size);
}
static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,
@@ -544,9 +550,12 @@ static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,
if (iscsilun->allocmap_valid == NULL) {
return false;
}
- size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
+ assert(iscsilun->cluster_size);
+ size = DIV_ROUND_UP(sector_num + nb_sectors,
+ iscsilun->cluster_size >> BDRV_SECTOR_BITS);
return (find_next_zero_bit(iscsilun->allocmap_valid, size,
- sector_num / iscsilun->cluster_sectors) == size);
+ sector_num * BDRV_SECTOR_SIZE /
+ iscsilun->cluster_size) == size);
}
static int coroutine_fn
@@ -781,16 +790,21 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
BlockDriverState *file;
/* check the block status from the beginning of the cluster
* containing the start sector */
- int64_t ret = iscsi_co_get_block_status(bs,
- sector_num - sector_num % iscsilun->cluster_sectors,
- BDRV_REQUEST_MAX_SECTORS, &pnum, &file);
+ int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS;
+ int head;
+ int64_t ret;
+
+ assert(cluster_sectors);
+ head = sector_num % cluster_sectors;
+ ret = iscsi_co_get_block_status(bs, sector_num - head,
+ BDRV_REQUEST_MAX_SECTORS, &pnum,
+ &file);
if (ret < 0) {
return ret;
}
/* if the whole request falls into an unallocated area we can avoid
- * to read and directly return zeroes instead */
- if (ret & BDRV_BLOCK_ZERO &&
- pnum >= nb_sectors + sector_num % iscsilun->cluster_sectors) {
+ * reading and directly return zeroes instead */
+ if (ret & BDRV_BLOCK_ZERO && pnum >= nb_sectors + head) {
qemu_iovec_memset(iov, 0, 0x00, iov->size);
return 0;
}
@@ -1930,8 +1944,8 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
* reasonable size */
if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 &&
iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) {
- iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran *
- iscsilun->block_size) >> BDRV_SECTOR_BITS;
+ iscsilun->cluster_size = iscsilun->bl.opt_unmap_gran *
+ iscsilun->block_size;
if (iscsilun->lbprz) {
ret = iscsi_allocmap_init(iscsilun, bs->open_flags);
}
@@ -2137,7 +2151,7 @@ static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
IscsiLun *iscsilun = bs->opaque;
bdi->unallocated_blocks_are_zero = iscsilun->lbprz;
bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws;
- bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE;
+ bdi->cluster_size = iscsilun->cluster_size;
return 0;
}
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 06/20] iscsi: Switch iscsi_allocmap_update() to byte-based
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (4 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 05/20] iscsi: Switch cluster_sectors to byte-based Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 07/20] iscsi: Switch to .bdrv_co_block_status() Eric Blake
` (13 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Ronnie Sahlberg,
Paolo Bonzini, Peter Lieven, Max Reitz
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert all uses of
the allocmap (no semantic change). Callers that already had bytes
available are simpler, and callers that now scale to bytes will be
easier to switch to byte-based in the future.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
---
v3-v5: no change
v2: rebase to count/bytes rename
---
block/iscsi.c | 90 +++++++++++++++++++++++++++++------------------------------
1 file changed, 44 insertions(+), 46 deletions(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index 8f903d8370..4896d50d6e 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -455,24 +455,22 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags)
}
static void
-iscsi_allocmap_update(IscsiLun *iscsilun, int64_t sector_num,
- int nb_sectors, bool allocated, bool valid)
+iscsi_allocmap_update(IscsiLun *iscsilun, int64_t offset,
+ int64_t bytes, bool allocated, bool valid)
{
int64_t cl_num_expanded, nb_cls_expanded, cl_num_shrunk, nb_cls_shrunk;
- int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS;
if (iscsilun->allocmap == NULL) {
return;
}
/* expand to entirely contain all affected clusters */
- assert(cluster_sectors);
- cl_num_expanded = sector_num / cluster_sectors;
- nb_cls_expanded = DIV_ROUND_UP(sector_num + nb_sectors,
- cluster_sectors) - cl_num_expanded;
+ assert(iscsilun->cluster_size);
+ cl_num_expanded = offset / iscsilun->cluster_size;
+ nb_cls_expanded = DIV_ROUND_UP(offset + bytes, iscsilun->cluster_size)
+ - cl_num_expanded;
/* shrink to touch only completely contained clusters */
- cl_num_shrunk = DIV_ROUND_UP(sector_num, cluster_sectors);
- nb_cls_shrunk = (sector_num + nb_sectors) / cluster_sectors
- - cl_num_shrunk;
+ cl_num_shrunk = DIV_ROUND_UP(offset, iscsilun->cluster_size);
+ nb_cls_shrunk = (offset + bytes) / iscsilun->cluster_size - cl_num_shrunk;
if (allocated) {
bitmap_set(iscsilun->allocmap, cl_num_expanded, nb_cls_expanded);
} else {
@@ -495,26 +493,26 @@ iscsi_allocmap_update(IscsiLun *iscsilun, int64_t sector_num,
}
static void
-iscsi_allocmap_set_allocated(IscsiLun *iscsilun, int64_t sector_num,
- int nb_sectors)
+iscsi_allocmap_set_allocated(IscsiLun *iscsilun, int64_t offset,
+ int64_t bytes)
{
- iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, true, true);
+ iscsi_allocmap_update(iscsilun, offset, bytes, true, true);
}
static void
-iscsi_allocmap_set_unallocated(IscsiLun *iscsilun, int64_t sector_num,
- int nb_sectors)
+iscsi_allocmap_set_unallocated(IscsiLun *iscsilun, int64_t offset,
+ int64_t bytes)
{
/* Note: if cache.direct=on the fifth argument to iscsi_allocmap_update
* is ignored, so this will in effect be an iscsi_allocmap_set_invalid.
*/
- iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, false, true);
+ iscsi_allocmap_update(iscsilun, offset, bytes, false, true);
}
-static void iscsi_allocmap_set_invalid(IscsiLun *iscsilun, int64_t sector_num,
- int nb_sectors)
+static void iscsi_allocmap_set_invalid(IscsiLun *iscsilun, int64_t offset,
+ int64_t bytes)
{
- iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, false, false);
+ iscsi_allocmap_update(iscsilun, offset, bytes, false, false);
}
static void iscsi_allocmap_invalidate(IscsiLun *iscsilun)
@@ -528,34 +526,30 @@ static void iscsi_allocmap_invalidate(IscsiLun *iscsilun)
}
static inline bool
-iscsi_allocmap_is_allocated(IscsiLun *iscsilun, int64_t sector_num,
- int nb_sectors)
+iscsi_allocmap_is_allocated(IscsiLun *iscsilun, int64_t offset,
+ int64_t bytes)
{
unsigned long size;
if (iscsilun->allocmap == NULL) {
return true;
}
assert(iscsilun->cluster_size);
- size = DIV_ROUND_UP(sector_num + nb_sectors,
- iscsilun->cluster_size >> BDRV_SECTOR_BITS);
+ size = DIV_ROUND_UP(offset + bytes, iscsilun->cluster_size);
return !(find_next_bit(iscsilun->allocmap, size,
- sector_num * BDRV_SECTOR_SIZE /
- iscsilun->cluster_size) == size);
+ offset / iscsilun->cluster_size) == size);
}
static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,
- int64_t sector_num, int nb_sectors)
+ int64_t offset, int64_t bytes)
{
unsigned long size;
if (iscsilun->allocmap_valid == NULL) {
return false;
}
assert(iscsilun->cluster_size);
- size = DIV_ROUND_UP(sector_num + nb_sectors,
- iscsilun->cluster_size >> BDRV_SECTOR_BITS);
+ size = DIV_ROUND_UP(offset + bytes, iscsilun->cluster_size);
return (find_next_zero_bit(iscsilun->allocmap_valid, size,
- sector_num * BDRV_SECTOR_SIZE /
- iscsilun->cluster_size) == size);
+ offset / iscsilun->cluster_size) == size);
}
static int coroutine_fn
@@ -637,12 +631,14 @@ retry:
}
if (iTask.status != SCSI_STATUS_GOOD) {
- iscsi_allocmap_set_invalid(iscsilun, sector_num, nb_sectors);
+ iscsi_allocmap_set_invalid(iscsilun, sector_num * BDRV_SECTOR_SIZE,
+ nb_sectors * BDRV_SECTOR_SIZE);
r = iTask.err_code;
goto out_unlock;
}
- iscsi_allocmap_set_allocated(iscsilun, sector_num, nb_sectors);
+ iscsi_allocmap_set_allocated(iscsilun, sector_num * BDRV_SECTOR_SIZE,
+ nb_sectors * BDRV_SECTOR_SIZE);
out_unlock:
qemu_mutex_unlock(&iscsilun->mutex);
@@ -737,9 +733,11 @@ retry:
}
if (ret & BDRV_BLOCK_ZERO) {
- iscsi_allocmap_set_unallocated(iscsilun, sector_num, *pnum);
+ iscsi_allocmap_set_unallocated(iscsilun, sector_num * BDRV_SECTOR_SIZE,
+ *pnum * BDRV_SECTOR_SIZE);
} else {
- iscsi_allocmap_set_allocated(iscsilun, sector_num, *pnum);
+ iscsi_allocmap_set_allocated(iscsilun, sector_num * BDRV_SECTOR_SIZE,
+ *pnum * BDRV_SECTOR_SIZE);
}
if (*pnum > nb_sectors) {
@@ -777,15 +775,19 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
/* if cache.direct is off and we have a valid entry in our allocation map
* we can skip checking the block status and directly return zeroes if
* the request falls within an unallocated area */
- if (iscsi_allocmap_is_valid(iscsilun, sector_num, nb_sectors) &&
- !iscsi_allocmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
+ if (iscsi_allocmap_is_valid(iscsilun, sector_num * BDRV_SECTOR_SIZE,
+ nb_sectors * BDRV_SECTOR_SIZE) &&
+ !iscsi_allocmap_is_allocated(iscsilun, sector_num * BDRV_SECTOR_SIZE,
+ nb_sectors * BDRV_SECTOR_SIZE)) {
qemu_iovec_memset(iov, 0, 0x00, iov->size);
return 0;
}
if (nb_sectors >= ISCSI_CHECKALLOC_THRES &&
- !iscsi_allocmap_is_valid(iscsilun, sector_num, nb_sectors) &&
- !iscsi_allocmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
+ !iscsi_allocmap_is_valid(iscsilun, sector_num * BDRV_SECTOR_SIZE,
+ nb_sectors * BDRV_SECTOR_SIZE) &&
+ !iscsi_allocmap_is_allocated(iscsilun, sector_num * BDRV_SECTOR_SIZE,
+ nb_sectors * BDRV_SECTOR_SIZE)) {
int pnum;
BlockDriverState *file;
/* check the block status from the beginning of the cluster
@@ -1154,8 +1156,7 @@ retry:
goto out_unlock;
}
- iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
- bytes >> BDRV_SECTOR_BITS);
+ iscsi_allocmap_set_invalid(iscsilun, offset, bytes);
out_unlock:
qemu_mutex_unlock(&iscsilun->mutex);
@@ -1253,18 +1254,15 @@ retry:
}
if (iTask.status != SCSI_STATUS_GOOD) {
- iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
- bytes >> BDRV_SECTOR_BITS);
+ iscsi_allocmap_set_invalid(iscsilun, offset, bytes);
r = iTask.err_code;
goto out_unlock;
}
if (flags & BDRV_REQ_MAY_UNMAP) {
- iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
- bytes >> BDRV_SECTOR_BITS);
+ iscsi_allocmap_set_invalid(iscsilun, offset, bytes);
} else {
- iscsi_allocmap_set_allocated(iscsilun, offset >> BDRV_SECTOR_BITS,
- bytes >> BDRV_SECTOR_BITS);
+ iscsi_allocmap_set_allocated(iscsilun, offset, bytes);
}
out_unlock:
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 07/20] iscsi: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (5 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 06/20] iscsi: Switch iscsi_allocmap_update() " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 08/20] null: " Eric Blake
` (12 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Ronnie Sahlberg,
Paolo Bonzini, Peter Lieven, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the iscsi driver accordingly. In this case,
it is handy to teach iscsi_co_block_status() to handle a NULL map
and file parameter, even though the block layer passes non-NULL
values, because we also call the function directly. For now, there
are no optimizations done based on the want_zero flag.
We can also make the simplification of asserting that the block
layer passed in aligned values.
Signed-off-by: Eric Blake <eblake@redhat.com>
---
v5: assert rather than check for alignment
v4: rebase to interface tweaks
v3: no change
v2: rebase to mapping parameter
---
block/iscsi.c | 67 ++++++++++++++++++++++++++++-------------------------------
1 file changed, 32 insertions(+), 35 deletions(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index 4896d50d6e..4c35403e27 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -647,28 +647,28 @@ out_unlock:
-static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors, int *pnum,
- BlockDriverState **file)
+static int coroutine_fn iscsi_co_block_status(BlockDriverState *bs,
+ bool want_zero, int64_t offset,
+ int64_t bytes, int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
{
IscsiLun *iscsilun = bs->opaque;
struct scsi_get_lba_status *lbas = NULL;
struct scsi_lba_status_descriptor *lbasd = NULL;
struct IscsiTask iTask;
- int64_t ret;
+ int ret;
iscsi_co_init_iscsitask(iscsilun, &iTask);
- if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
- ret = -EINVAL;
- goto out;
- }
+ assert(QEMU_IS_ALIGNED(offset | bytes, iscsilun->block_size));
/* default to all sectors allocated */
- ret = BDRV_BLOCK_DATA;
- ret |= (sector_num << BDRV_SECTOR_BITS) | BDRV_BLOCK_OFFSET_VALID;
- *pnum = nb_sectors;
+ ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
+ if (map) {
+ *map = offset;
+ }
+ *pnum = bytes;
/* LUN does not support logical block provisioning */
if (!iscsilun->lbpme) {
@@ -678,7 +678,7 @@ static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
qemu_mutex_lock(&iscsilun->mutex);
retry:
if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
- sector_qemu2lun(sector_num, iscsilun),
+ offset / iscsilun->block_size,
8 + 16, iscsi_co_generic_cb,
&iTask) == NULL) {
ret = -ENOMEM;
@@ -717,12 +717,12 @@ retry:
lbasd = &lbas->descriptors[0];
- if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
+ if (offset / iscsilun->block_size != lbasd->lba) {
ret = -EIO;
goto out_unlock;
}
- *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun);
+ *pnum = lbasd->num_blocks * iscsilun->block_size;
if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
@@ -733,15 +733,13 @@ retry:
}
if (ret & BDRV_BLOCK_ZERO) {
- iscsi_allocmap_set_unallocated(iscsilun, sector_num * BDRV_SECTOR_SIZE,
- *pnum * BDRV_SECTOR_SIZE);
+ iscsi_allocmap_set_unallocated(iscsilun, offset, *pnum);
} else {
- iscsi_allocmap_set_allocated(iscsilun, sector_num * BDRV_SECTOR_SIZE,
- *pnum * BDRV_SECTOR_SIZE);
+ iscsi_allocmap_set_allocated(iscsilun, offset, *pnum);
}
- if (*pnum > nb_sectors) {
- *pnum = nb_sectors;
+ if (*pnum > bytes) {
+ *pnum = bytes;
}
out_unlock:
qemu_mutex_unlock(&iscsilun->mutex);
@@ -749,7 +747,7 @@ out:
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
}
- if (ret > 0 && ret & BDRV_BLOCK_OFFSET_VALID) {
+ if (ret > 0 && ret & BDRV_BLOCK_OFFSET_VALID && file) {
*file = bs;
}
return ret;
@@ -788,25 +786,24 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
nb_sectors * BDRV_SECTOR_SIZE) &&
!iscsi_allocmap_is_allocated(iscsilun, sector_num * BDRV_SECTOR_SIZE,
nb_sectors * BDRV_SECTOR_SIZE)) {
- int pnum;
- BlockDriverState *file;
+ int64_t pnum;
/* check the block status from the beginning of the cluster
* containing the start sector */
- int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS;
- int head;
- int64_t ret;
+ int64_t head;
+ int ret;
- assert(cluster_sectors);
- head = sector_num % cluster_sectors;
- ret = iscsi_co_get_block_status(bs, sector_num - head,
- BDRV_REQUEST_MAX_SECTORS, &pnum,
- &file);
+ assert(iscsilun->cluster_size);
+ head = (sector_num * BDRV_SECTOR_SIZE) % iscsilun->cluster_size;
+ ret = iscsi_co_block_status(bs, false,
+ sector_num * BDRV_SECTOR_SIZE - head,
+ BDRV_REQUEST_MAX_BYTES, &pnum, NULL, NULL);
if (ret < 0) {
return ret;
}
/* if the whole request falls into an unallocated area we can avoid
* reading and directly return zeroes instead */
- if (ret & BDRV_BLOCK_ZERO && pnum >= nb_sectors + head) {
+ if (ret & BDRV_BLOCK_ZERO &&
+ pnum >= nb_sectors * BDRV_SECTOR_SIZE + head) {
qemu_iovec_memset(iov, 0, 0x00, iov->size);
return 0;
}
@@ -2192,7 +2189,7 @@ static BlockDriver bdrv_iscsi = {
.bdrv_truncate = iscsi_truncate,
.bdrv_refresh_limits = iscsi_refresh_limits,
- .bdrv_co_get_block_status = iscsi_co_get_block_status,
+ .bdrv_co_block_status = iscsi_co_block_status,
.bdrv_co_pdiscard = iscsi_co_pdiscard,
.bdrv_co_pwrite_zeroes = iscsi_co_pwrite_zeroes,
.bdrv_co_readv = iscsi_co_readv,
@@ -2227,7 +2224,7 @@ static BlockDriver bdrv_iser = {
.bdrv_truncate = iscsi_truncate,
.bdrv_refresh_limits = iscsi_refresh_limits,
- .bdrv_co_get_block_status = iscsi_co_get_block_status,
+ .bdrv_co_block_status = iscsi_co_block_status,
.bdrv_co_pdiscard = iscsi_co_pdiscard,
.bdrv_co_pwrite_zeroes = iscsi_co_pwrite_zeroes,
.bdrv_co_readv = iscsi_co_readv,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 08/20] null: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (6 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 07/20] iscsi: Switch to .bdrv_co_block_status() Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 09/20] parallels: " Eric Blake
` (11 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the null driver accordingly.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: minor fix to type of 'ret'
v4: rebase to interface tweak
v3: no change
v2: rebase to mapping parameter
---
block/null.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/block/null.c b/block/null.c
index dd9c13f9ba..b762246860 100644
--- a/block/null.c
+++ b/block/null.c
@@ -223,22 +223,23 @@ static int null_reopen_prepare(BDRVReopenState *reopen_state,
return 0;
}
-static int64_t coroutine_fn null_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors, int *pnum,
- BlockDriverState **file)
+static int coroutine_fn null_co_block_status(BlockDriverState *bs,
+ bool want_zero, int64_t offset,
+ int64_t bytes, int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
{
BDRVNullState *s = bs->opaque;
- off_t start = sector_num * BDRV_SECTOR_SIZE;
+ int ret = BDRV_BLOCK_OFFSET_VALID;
- *pnum = nb_sectors;
+ *pnum = bytes;
+ *map = offset;
*file = bs;
if (s->read_zeroes) {
- return BDRV_BLOCK_OFFSET_VALID | start | BDRV_BLOCK_ZERO;
- } else {
- return BDRV_BLOCK_OFFSET_VALID | start;
+ ret |= BDRV_BLOCK_ZERO;
}
+ return ret;
}
static void null_refresh_filename(BlockDriverState *bs, QDict *opts)
@@ -270,7 +271,7 @@ static BlockDriver bdrv_null_co = {
.bdrv_co_flush_to_disk = null_co_flush,
.bdrv_reopen_prepare = null_reopen_prepare,
- .bdrv_co_get_block_status = null_co_get_block_status,
+ .bdrv_co_block_status = null_co_block_status,
.bdrv_refresh_filename = null_refresh_filename,
};
@@ -290,7 +291,7 @@ static BlockDriver bdrv_null_aio = {
.bdrv_aio_flush = null_aio_flush,
.bdrv_reopen_prepare = null_reopen_prepare,
- .bdrv_co_get_block_status = null_co_get_block_status,
+ .bdrv_co_block_status = null_co_block_status,
.bdrv_refresh_filename = null_refresh_filename,
};
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 09/20] parallels: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (7 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 08/20] null: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 10/20] qcow: " Eric Blake
` (10 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Stefan Hajnoczi,
Denis V. Lunev, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the parallels driver accordingly. Note that
the internal function block_status() is still sector-based, because
it is still in use by other sector-based functions; but that's okay
because request_alignment is 512 as a result of those functions.
For now, no optimizations are added based on the mapping hint.
Signed-off-by: Eric Blake <eblake@redhat.com>
---
v5: fix pnum when return is 0
v4: rebase to interface tweak, R-b dropped
v3: no change
v2: rebase to mapping parameter; it is ignored, so R-b kept
---
block/parallels.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/block/parallels.c b/block/parallels.c
index 9545761f49..9a3d3748ae 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -280,23 +280,31 @@ static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
}
-static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
+static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset,
+ int64_t bytes,
+ int64_t *pnum,
+ int64_t *map,
+ BlockDriverState **file)
{
BDRVParallelsState *s = bs->opaque;
- int64_t offset;
+ int count;
+ assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
qemu_co_mutex_lock(&s->lock);
- offset = block_status(s, sector_num, nb_sectors, pnum);
+ offset = block_status(s, offset >> BDRV_SECTOR_BITS,
+ bytes >> BDRV_SECTOR_BITS, &count);
qemu_co_mutex_unlock(&s->lock);
+ *pnum = count * BDRV_SECTOR_SIZE;
if (offset < 0) {
return 0;
}
+ *map = offset;
*file = bs->file->bs;
- return (offset << BDRV_SECTOR_BITS) |
- BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
+ return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
}
static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
@@ -793,7 +801,7 @@ static BlockDriver bdrv_parallels = {
.bdrv_open = parallels_open,
.bdrv_close = parallels_close,
.bdrv_child_perm = bdrv_format_default_perms,
- .bdrv_co_get_block_status = parallels_co_get_block_status,
+ .bdrv_co_block_status = parallels_co_block_status,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_flush_to_os = parallels_co_flush_to_os,
.bdrv_co_readv = parallels_co_readv,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 10/20] qcow: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (8 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 09/20] parallels: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 11/20] qcow2: " Eric Blake
` (9 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the qcow driver accordingly. There is no
intent to optimize based on the want_zero flag for this format.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: no change
v4: rebase to interface tweak
v3: rebase to master
v2: rebase to mapping flag
---
block/qcow.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/block/qcow.c b/block/qcow.c
index 9569deeaf0..f09661dc0c 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -513,23 +513,28 @@ static int get_cluster_offset(BlockDriverState *bs,
return 1;
}
-static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
+static int coroutine_fn qcow_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
{
BDRVQcowState *s = bs->opaque;
- int index_in_cluster, n, ret;
+ int index_in_cluster, ret;
+ int64_t n;
uint64_t cluster_offset;
qemu_co_mutex_lock(&s->lock);
- ret = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0, &cluster_offset);
+ ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset);
qemu_co_mutex_unlock(&s->lock);
if (ret < 0) {
return ret;
}
- index_in_cluster = sector_num & (s->cluster_sectors - 1);
- n = s->cluster_sectors - index_in_cluster;
- if (n > nb_sectors)
- n = nb_sectors;
+ index_in_cluster = offset & (s->cluster_size - 1);
+ n = s->cluster_size - index_in_cluster;
+ if (n > bytes) {
+ n = bytes;
+ }
*pnum = n;
if (!cluster_offset) {
return 0;
@@ -537,9 +542,9 @@ static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs,
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypto) {
return BDRV_BLOCK_DATA;
}
- cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
+ *map = cluster_offset | index_in_cluster;
*file = bs->file->bs;
- return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | cluster_offset;
+ return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
}
static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
@@ -1111,7 +1116,7 @@ static BlockDriver bdrv_qcow = {
.bdrv_co_readv = qcow_co_readv,
.bdrv_co_writev = qcow_co_writev,
- .bdrv_co_get_block_status = qcow_co_get_block_status,
+ .bdrv_co_block_status = qcow_co_block_status,
.bdrv_make_empty = qcow_make_empty,
.bdrv_co_pwritev_compressed = qcow_co_pwritev_compressed,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 11/20] qcow2: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (9 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 10/20] qcow: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 12/20] qed: " Eric Blake
` (8 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the qcow2 driver accordingly.
For now, we are ignoring the 'want_zero' hint. However, it should
be relatively straightforward to honor the hint as a way to return
larger *pnum values when we have consecutive clusters with the same
data/zero status but which differ only in having non-consecutive
mappings.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: no change
v4: update to interface tweak
v3: no change
v2: rebase to mapping flag
---
block/qcow2.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 1914a940e5..642fa3bc8f 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1637,32 +1637,34 @@ static void qcow2_join_options(QDict *options, QDict *old_options)
}
}
-static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
+static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t count,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
{
BDRVQcow2State *s = bs->opaque;
uint64_t cluster_offset;
int index_in_cluster, ret;
unsigned int bytes;
- int64_t status = 0;
+ int status = 0;
- bytes = MIN(INT_MAX, nb_sectors * BDRV_SECTOR_SIZE);
+ bytes = MIN(INT_MAX, count);
qemu_co_mutex_lock(&s->lock);
- ret = qcow2_get_cluster_offset(bs, sector_num << BDRV_SECTOR_BITS, &bytes,
- &cluster_offset);
+ ret = qcow2_get_cluster_offset(bs, offset, &bytes, &cluster_offset);
qemu_co_mutex_unlock(&s->lock);
if (ret < 0) {
return ret;
}
- *pnum = bytes >> BDRV_SECTOR_BITS;
+ *pnum = bytes;
if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED &&
!s->crypto) {
- index_in_cluster = sector_num & (s->cluster_sectors - 1);
- cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
+ index_in_cluster = offset & (s->cluster_size - 1);
+ *map = cluster_offset | index_in_cluster;
*file = bs->file->bs;
- status |= BDRV_BLOCK_OFFSET_VALID | cluster_offset;
+ status |= BDRV_BLOCK_OFFSET_VALID;
}
if (ret == QCOW2_CLUSTER_ZERO_PLAIN || ret == QCOW2_CLUSTER_ZERO_ALLOC) {
status |= BDRV_BLOCK_ZERO;
@@ -4355,7 +4357,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_child_perm = bdrv_format_default_perms,
.bdrv_create = qcow2_create,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
- .bdrv_co_get_block_status = qcow2_co_get_block_status,
+ .bdrv_co_block_status = qcow2_co_block_status,
.bdrv_co_preadv = qcow2_co_preadv,
.bdrv_co_pwritev = qcow2_co_pwritev,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 12/20] qed: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (10 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 11/20] qcow2: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 13/20] raw: " Eric Blake
` (7 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Stefan Hajnoczi,
Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the qed driver accordingly, taking the opportunity
to inline qed_is_allocated_cb() into its lone caller (the callback
used to be important, until we switched qed to coroutines). There is
no intent to optimize based on the want_zero flag for this format.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: initialize len before qed_find_cluster() [Vladimir]
v4: rebase to interface change, inline pointless callback
v3: no change
v2: rebase to mapping flag, fix mask in qed_is_allocated_cb
---
block/qed.c | 84 +++++++++++++++++++++----------------------------------------
1 file changed, 28 insertions(+), 56 deletions(-)
diff --git a/block/qed.c b/block/qed.c
index 821dcaa055..13fbc3e2f1 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -688,74 +688,46 @@ finish:
return ret;
}
-typedef struct {
- BlockDriverState *bs;
- Coroutine *co;
- uint64_t pos;
- int64_t status;
- int *pnum;
- BlockDriverState **file;
-} QEDIsAllocatedCB;
-
-/* Called with table_lock held. */
-static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t len)
-{
- QEDIsAllocatedCB *cb = opaque;
- BDRVQEDState *s = cb->bs->opaque;
- *cb->pnum = len / BDRV_SECTOR_SIZE;
- switch (ret) {
- case QED_CLUSTER_FOUND:
- offset |= qed_offset_into_cluster(s, cb->pos);
- cb->status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset;
- *cb->file = cb->bs->file->bs;
- break;
- case QED_CLUSTER_ZERO:
- cb->status = BDRV_BLOCK_ZERO;
- break;
- case QED_CLUSTER_L2:
- case QED_CLUSTER_L1:
- cb->status = 0;
- break;
- default:
- assert(ret < 0);
- cb->status = ret;
- break;
- }
-
- if (cb->co) {
- aio_co_wake(cb->co);
- }
-}
-
-static int64_t coroutine_fn bdrv_qed_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors, int *pnum,
+static int coroutine_fn bdrv_qed_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t pos, int64_t bytes,
+ int64_t *pnum, int64_t *map,
BlockDriverState **file)
{
BDRVQEDState *s = bs->opaque;
- size_t len = (size_t)nb_sectors * BDRV_SECTOR_SIZE;
- QEDIsAllocatedCB cb = {
- .bs = bs,
- .pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE,
- .status = BDRV_BLOCK_OFFSET_MASK,
- .pnum = pnum,
- .file = file,
- };
+ size_t len = MIN(bytes, SIZE_MAX);
+ int status;
QEDRequest request = { .l2_table = NULL };
uint64_t offset;
int ret;
qemu_co_mutex_lock(&s->table_lock);
- ret = qed_find_cluster(s, &request, cb.pos, &len, &offset);
- qed_is_allocated_cb(&cb, ret, offset, len);
+ ret = qed_find_cluster(s, &request, pos, &len, &offset);
- /* The callback was invoked immediately */
- assert(cb.status != BDRV_BLOCK_OFFSET_MASK);
+ *pnum = len;
+ switch (ret) {
+ case QED_CLUSTER_FOUND:
+ *map = offset | qed_offset_into_cluster(s, pos);
+ status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
+ *file = bs->file->bs;
+ break;
+ case QED_CLUSTER_ZERO:
+ status = BDRV_BLOCK_ZERO;
+ break;
+ case QED_CLUSTER_L2:
+ case QED_CLUSTER_L1:
+ status = 0;
+ break;
+ default:
+ assert(ret < 0);
+ status = ret;
+ break;
+ }
qed_unref_l2_cache_entry(request.l2_table);
qemu_co_mutex_unlock(&s->table_lock);
- return cb.status;
+ return status;
}
static BDRVQEDState *acb_to_s(QEDAIOCB *acb)
@@ -1595,7 +1567,7 @@ static BlockDriver bdrv_qed = {
.bdrv_child_perm = bdrv_format_default_perms,
.bdrv_create = bdrv_qed_create,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
- .bdrv_co_get_block_status = bdrv_qed_co_get_block_status,
+ .bdrv_co_block_status = bdrv_qed_co_block_status,
.bdrv_co_readv = bdrv_qed_co_readv,
.bdrv_co_writev = bdrv_qed_co_writev,
.bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 13/20] raw: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (11 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 12/20] qed: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 14/20] sheepdog: " Eric Blake
` (6 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the raw driver accordingly.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: no change
v4: rebase to interface tweak
v3: no change
v2: rebase to mapping
---
block/raw-format.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/block/raw-format.c b/block/raw-format.c
index ab552c0954..830243a8e4 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -250,17 +250,17 @@ fail:
return ret;
}
-static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num,
- int nb_sectors, int *pnum,
+static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
+ bool want_zero, int64_t offset,
+ int64_t bytes, int64_t *pnum,
+ int64_t *map,
BlockDriverState **file)
{
BDRVRawState *s = bs->opaque;
- *pnum = nb_sectors;
+ *pnum = bytes;
*file = bs->file->bs;
- sector_num += s->offset / BDRV_SECTOR_SIZE;
- return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
- (sector_num << BDRV_SECTOR_BITS);
+ *map = offset + s->offset;
+ return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
}
static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
@@ -496,7 +496,7 @@ BlockDriver bdrv_raw = {
.bdrv_co_pwritev = &raw_co_pwritev,
.bdrv_co_pwrite_zeroes = &raw_co_pwrite_zeroes,
.bdrv_co_pdiscard = &raw_co_pdiscard,
- .bdrv_co_get_block_status = &raw_co_get_block_status,
+ .bdrv_co_block_status = &raw_co_block_status,
.bdrv_truncate = &raw_truncate,
.bdrv_getlength = &raw_getlength,
.has_variable_length = true,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 14/20] sheepdog: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (12 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 13/20] raw: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 15/20] vdi: Avoid bitrot of debugging code Eric Blake
` (5 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Hitoshi Mitake,
Liu Yuan, Jeff Cody, Max Reitz, open list:Sheepdog
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the sheepdog driver accordingly.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: no change
v4: update to interface tweak
v3: no change
v2: rebase to mapping flag
---
block/sheepdog.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 696a71442a..0af8b07892 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2988,19 +2988,19 @@ static coroutine_fn int sd_co_pdiscard(BlockDriverState *bs, int64_t offset,
return acb.ret;
}
-static coroutine_fn int64_t
-sd_co_get_block_status(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
- int *pnum, BlockDriverState **file)
+static coroutine_fn int
+sd_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
+ int64_t bytes, int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
{
BDRVSheepdogState *s = bs->opaque;
SheepdogInode *inode = &s->inode;
uint32_t object_size = (UINT32_C(1) << inode->block_size_shift);
- uint64_t offset = sector_num * BDRV_SECTOR_SIZE;
unsigned long start = offset / object_size,
- end = DIV_ROUND_UP((sector_num + nb_sectors) *
- BDRV_SECTOR_SIZE, object_size);
+ end = DIV_ROUND_UP(offset + bytes, object_size);
unsigned long idx;
- int64_t ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset;
+ *map = offset;
+ int ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
for (idx = start; idx < end; idx++) {
if (inode->data_vdi_id[idx] == 0) {
@@ -3017,9 +3017,9 @@ sd_co_get_block_status(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
}
}
- *pnum = (idx - start) * object_size / BDRV_SECTOR_SIZE;
- if (*pnum > nb_sectors) {
- *pnum = nb_sectors;
+ *pnum = (idx - start) * object_size;
+ if (*pnum > bytes) {
+ *pnum = bytes;
}
if (ret > 0 && ret & BDRV_BLOCK_OFFSET_VALID) {
*file = bs;
@@ -3097,7 +3097,7 @@ static BlockDriver bdrv_sheepdog = {
.bdrv_co_writev = sd_co_writev,
.bdrv_co_flush_to_disk = sd_co_flush_to_disk,
.bdrv_co_pdiscard = sd_co_pdiscard,
- .bdrv_co_get_block_status = sd_co_get_block_status,
+ .bdrv_co_block_status = sd_co_block_status,
.bdrv_snapshot_create = sd_snapshot_create,
.bdrv_snapshot_goto = sd_snapshot_goto,
@@ -3133,7 +3133,7 @@ static BlockDriver bdrv_sheepdog_tcp = {
.bdrv_co_writev = sd_co_writev,
.bdrv_co_flush_to_disk = sd_co_flush_to_disk,
.bdrv_co_pdiscard = sd_co_pdiscard,
- .bdrv_co_get_block_status = sd_co_get_block_status,
+ .bdrv_co_block_status = sd_co_block_status,
.bdrv_snapshot_create = sd_snapshot_create,
.bdrv_snapshot_goto = sd_snapshot_goto,
@@ -3169,7 +3169,7 @@ static BlockDriver bdrv_sheepdog_unix = {
.bdrv_co_writev = sd_co_writev,
.bdrv_co_flush_to_disk = sd_co_flush_to_disk,
.bdrv_co_pdiscard = sd_co_pdiscard,
- .bdrv_co_get_block_status = sd_co_get_block_status,
+ .bdrv_co_block_status = sd_co_block_status,
.bdrv_snapshot_create = sd_snapshot_create,
.bdrv_snapshot_goto = sd_snapshot_goto,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 15/20] vdi: Avoid bitrot of debugging code
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (13 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 14/20] sheepdog: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 16/20] vdi: Switch to .bdrv_co_block_status() Eric Blake
` (4 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Stefan Weil,
Max Reitz
Rework the debug define so that we always get -Wformat checking,
even when debugging is disabled.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v2-v5: no change
---
block/vdi.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/block/vdi.c b/block/vdi.c
index 8da5dfc897..6f83221ddc 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -86,12 +86,18 @@
#define DEFAULT_CLUSTER_SIZE (1 * MiB)
#if defined(CONFIG_VDI_DEBUG)
-#define logout(fmt, ...) \
- fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__)
+#define VDI_DEBUG 1
#else
-#define logout(fmt, ...) ((void)0)
+#define VDI_DEBUG 0
#endif
+#define logout(fmt, ...) \
+ do { \
+ if (VDI_DEBUG) { \
+ fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__); \
+ } \
+ } while (0)
+
/* Image signature. */
#define VDI_SIGNATURE 0xbeda107f
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 16/20] vdi: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (14 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 15/20] vdi: Avoid bitrot of debugging code Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 17/20] vmdk: " Eric Blake
` (3 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Stefan Weil,
Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the vdi driver accordingly. Note that the
TODO is already covered (the block layer guarantees bounds of its
requests), and that we can remove the now-unused s->block_sectors.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: fix pnum when offset rounded down to block_size [Vladimir]
v4: rebase to interface tweak
v3: no change
v2: rebase to mapping flag
---
block/vdi.c | 33 +++++++++++++--------------------
1 file changed, 13 insertions(+), 20 deletions(-)
diff --git a/block/vdi.c b/block/vdi.c
index 6f83221ddc..f309562d36 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -171,8 +171,6 @@ typedef struct {
uint32_t *bmap;
/* Size of block (bytes). */
uint32_t block_size;
- /* Size of block (sectors). */
- uint32_t block_sectors;
/* First sector of block map. */
uint32_t bmap_sector;
/* VDI header (converted to host endianness). */
@@ -462,7 +460,6 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
bs->total_sectors = header.disk_size / SECTOR_SIZE;
s->block_size = header.block_size;
- s->block_sectors = header.block_size / SECTOR_SIZE;
s->bmap_sector = header.offset_bmap / SECTOR_SIZE;
s->header = header;
@@ -508,33 +505,29 @@ static int vdi_reopen_prepare(BDRVReopenState *state,
return 0;
}
-static int64_t coroutine_fn vdi_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
+static int coroutine_fn vdi_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
{
- /* TODO: Check for too large sector_num (in bdrv_is_allocated or here). */
BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
- size_t bmap_index = sector_num / s->block_sectors;
- size_t sector_in_block = sector_num % s->block_sectors;
- int n_sectors = s->block_sectors - sector_in_block;
+ size_t bmap_index = offset / s->block_size;
+ size_t index_in_block = offset % s->block_size;
uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]);
- uint64_t offset;
int result;
- logout("%p, %" PRId64 ", %d, %p\n", bs, sector_num, nb_sectors, pnum);
- if (n_sectors > nb_sectors) {
- n_sectors = nb_sectors;
- }
- *pnum = n_sectors;
+ logout("%p, %" PRId64 ", %" PRId64 ", %p\n", bs, offset, bytes, pnum);
+ *pnum = MIN(s->block_size - index_in_block, bytes);
result = VDI_IS_ALLOCATED(bmap_entry);
if (!result) {
return 0;
}
- offset = s->header.offset_data +
- (uint64_t)bmap_entry * s->block_size +
- sector_in_block * SECTOR_SIZE;
+ *map = s->header.offset_data + (uint64_t)bmap_entry * s->block_size +
+ index_in_block;
*file = bs->file->bs;
- return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset;
+ return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
}
static int coroutine_fn
@@ -902,7 +895,7 @@ static BlockDriver bdrv_vdi = {
.bdrv_child_perm = bdrv_format_default_perms,
.bdrv_create = vdi_create,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
- .bdrv_co_get_block_status = vdi_co_get_block_status,
+ .bdrv_co_block_status = vdi_co_block_status,
.bdrv_make_empty = vdi_make_empty,
.bdrv_co_preadv = vdi_co_preadv,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 17/20] vmdk: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (15 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 16/20] vdi: Switch to .bdrv_co_block_status() Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 18/20] vpc: " Eric Blake
` (2 subsequent siblings)
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the vmdk driver accordingly. Drop the
now-unused vmdk_find_index_in_cluster().
Also, fix a pre-existing bug: if find_extent() fails (unlikely,
since the block layer did a bounds check), then we must return a
failure, rather than 0.
Signed-off-by: Eric Blake <eblake@redhat.com>
---
v5: drop dead code [Vladimir], return error on find_extent() failure
v4: rebase to interface tweak
v3: no change
v2: rebase to mapping flag
---
block/vmdk.c | 38 ++++++++++++++------------------------
1 file changed, 14 insertions(+), 24 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index c665bcc977..8ae36e7a45 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1295,33 +1295,27 @@ static inline uint64_t vmdk_find_offset_in_cluster(VmdkExtent *extent,
return extent_relative_offset % cluster_size;
}
-static inline uint64_t vmdk_find_index_in_cluster(VmdkExtent *extent,
- int64_t sector_num)
-{
- uint64_t offset;
- offset = vmdk_find_offset_in_cluster(extent, sector_num * BDRV_SECTOR_SIZE);
- return offset / BDRV_SECTOR_SIZE;
-}
-
-static int64_t coroutine_fn vmdk_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
+static int coroutine_fn vmdk_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
{
BDRVVmdkState *s = bs->opaque;
int64_t index_in_cluster, n, ret;
- uint64_t offset;
+ uint64_t cluster_offset;
VmdkExtent *extent;
- extent = find_extent(s, sector_num, NULL);
+ extent = find_extent(s, offset >> BDRV_SECTOR_BITS, NULL);
if (!extent) {
- return 0;
+ return -EIO;
}
qemu_co_mutex_lock(&s->lock);
- ret = get_cluster_offset(bs, extent, NULL,
- sector_num * 512, false, &offset,
+ ret = get_cluster_offset(bs, extent, NULL, offset, false, &cluster_offset,
0, 0);
qemu_co_mutex_unlock(&s->lock);
- index_in_cluster = vmdk_find_index_in_cluster(extent, sector_num);
+ index_in_cluster = vmdk_find_offset_in_cluster(extent, offset);
switch (ret) {
case VMDK_ERROR:
ret = -EIO;
@@ -1336,18 +1330,14 @@ static int64_t coroutine_fn vmdk_co_get_block_status(BlockDriverState *bs,
ret = BDRV_BLOCK_DATA;
if (!extent->compressed) {
ret |= BDRV_BLOCK_OFFSET_VALID;
- ret |= (offset + (index_in_cluster << BDRV_SECTOR_BITS))
- & BDRV_BLOCK_OFFSET_MASK;
+ *map = cluster_offset + index_in_cluster;
}
*file = extent->file->bs;
break;
}
- n = extent->cluster_sectors - index_in_cluster;
- if (n > nb_sectors) {
- n = nb_sectors;
- }
- *pnum = n;
+ n = extent->cluster_sectors * BDRV_SECTOR_SIZE - index_in_cluster;
+ *pnum = MIN(n, bytes);
return ret;
}
@@ -2393,7 +2383,7 @@ static BlockDriver bdrv_vmdk = {
.bdrv_close = vmdk_close,
.bdrv_create = vmdk_create,
.bdrv_co_flush_to_disk = vmdk_co_flush,
- .bdrv_co_get_block_status = vmdk_co_get_block_status,
+ .bdrv_co_block_status = vmdk_co_block_status,
.bdrv_get_allocated_file_size = vmdk_get_allocated_file_size,
.bdrv_has_zero_init = vmdk_has_zero_init,
.bdrv_get_specific_info = vmdk_get_specific_info,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 18/20] vpc: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (16 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 17/20] vmdk: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 19/20] vvfat: " Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 20/20] block: Drop unused .bdrv_co_get_block_status() Eric Blake
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the vpc driver accordingly. Drop the now-unused
get_sector_offset().
Signed-off-by: Eric Blake <eblake@redhat.com>
---
v5: fix incorrect rounding in 'map' and bad loop condition [Vladimir]
v4: rebase to interface tweak
v3: rebase to master
v2: drop get_sector_offset() [Kevin], rebase to mapping flag
---
block/vpc.c | 43 ++++++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 21 deletions(-)
diff --git a/block/vpc.c b/block/vpc.c
index 1576d7b595..0000b5b9b4 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -705,53 +705,54 @@ fail:
return ret;
}
-static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
+static int coroutine_fn vpc_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
{
BDRVVPCState *s = bs->opaque;
VHDFooter *footer = (VHDFooter*) s->footer_buf;
- int64_t start, offset;
+ int64_t image_offset;
bool allocated;
- int64_t ret;
+ int ret;
int n;
if (be32_to_cpu(footer->type) == VHD_FIXED) {
- *pnum = nb_sectors;
+ *pnum = bytes;
+ *map = offset;
*file = bs->file->bs;
- return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
- (sector_num << BDRV_SECTOR_BITS);
+ return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
}
qemu_co_mutex_lock(&s->lock);
- offset = get_image_offset(bs, sector_num << BDRV_SECTOR_BITS, false, NULL);
- start = offset;
- allocated = (offset != -1);
+ image_offset = get_image_offset(bs, offset, false, NULL);
+ allocated = (image_offset != -1);
*pnum = 0;
ret = 0;
do {
/* All sectors in a block are contiguous (without using the bitmap) */
- n = ROUND_UP(sector_num + 1, s->block_size / BDRV_SECTOR_SIZE)
- - sector_num;
- n = MIN(n, nb_sectors);
+ n = ROUND_UP(offset + 1, s->block_size) - offset;
+ n = MIN(n, bytes);
*pnum += n;
- sector_num += n;
- nb_sectors -= n;
+ offset += n;
+ bytes -= n;
/* *pnum can't be greater than one block for allocated
* sectors since there is always a bitmap in between. */
if (allocated) {
*file = bs->file->bs;
- ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;
+ *map = image_offset;
+ ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
break;
}
- if (nb_sectors == 0) {
+ if (bytes == 0) {
break;
}
- offset = get_image_offset(bs, sector_num << BDRV_SECTOR_BITS, false,
- NULL);
- } while (offset == -1);
+ image_offset = get_image_offset(bs, offset, false, NULL);
+ } while (image_offset == -1);
qemu_co_mutex_unlock(&s->lock);
return ret;
@@ -1097,7 +1098,7 @@ static BlockDriver bdrv_vpc = {
.bdrv_co_preadv = vpc_co_preadv,
.bdrv_co_pwritev = vpc_co_pwritev,
- .bdrv_co_get_block_status = vpc_co_get_block_status,
+ .bdrv_co_block_status = vpc_co_block_status,
.bdrv_get_info = vpc_get_info,
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 19/20] vvfat: Switch to .bdrv_co_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (17 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 18/20] vpc: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 20/20] block: Drop unused .bdrv_co_get_block_status() Eric Blake
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the vvfat driver accordingly. Note that we
can rely on the block driver having already clamped limits to our
block size, and simplify accordingly.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: no change
v4: rebase to interface tweak
v3: no change
v2: rebase to earlier changes, simplify
---
block/vvfat.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/block/vvfat.c b/block/vvfat.c
index a690595f2c..37d85a389f 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -3086,15 +3086,13 @@ vvfat_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
return ret;
}
-static int64_t coroutine_fn vvfat_co_get_block_status(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, int *n, BlockDriverState **file)
+static int coroutine_fn vvfat_co_block_status(BlockDriverState *bs,
+ bool want_zero, int64_t offset,
+ int64_t bytes, int64_t *n,
+ int64_t *map,
+ BlockDriverState **file)
{
- *n = bs->total_sectors - sector_num;
- if (*n > nb_sectors) {
- *n = nb_sectors;
- } else if (*n < 0) {
- return 0;
- }
+ *n = bytes;
return BDRV_BLOCK_DATA;
}
@@ -3255,7 +3253,7 @@ static BlockDriver bdrv_vvfat = {
.bdrv_co_preadv = vvfat_co_preadv,
.bdrv_co_pwritev = vvfat_co_pwritev,
- .bdrv_co_get_block_status = vvfat_co_get_block_status,
+ .bdrv_co_block_status = vvfat_co_block_status,
};
static void bdrv_vvfat_init(void)
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread* [Qemu-devel] [PATCH v5 20/20] block: Drop unused .bdrv_co_get_block_status()
2017-12-01 1:42 [Qemu-devel] [PATCH v5 00/20] add byte-based block_status driver callbacks Eric Blake
` (18 preceding siblings ...)
2017-12-01 1:42 ` [Qemu-devel] [PATCH v5 19/20] vvfat: " Eric Blake
@ 2017-12-01 1:42 ` Eric Blake
19 siblings, 0 replies; 26+ messages in thread
From: Eric Blake @ 2017-12-01 1:42 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, jsnow, famz, qemu-block, vsementsov, Stefan Hajnoczi,
Max Reitz
We are gradually moving away from sector-based interfaces, towards
byte-based. Now that all drivers have been updated to provide the
byte-based .bdrv_co_block_status(), we can delete the sector-based
interface.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v5: rebase to master
v4: rebase to interface tweak
v3: no change
v2: rebase to earlier changes
---
include/block/block_int.h | 3 ---
block/io.c | 34 +---------------------------------
2 files changed, 1 insertion(+), 36 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 980333c671..df9b62934d 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -215,9 +215,6 @@ struct BlockDriver {
* in turn, the driver must return an error or set pnum to an
* aligned non-zero value.
*/
- int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, int *pnum,
- BlockDriverState **file);
int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs,
bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
int64_t *map, BlockDriverState **file);
diff --git a/block/io.c b/block/io.c
index 49d299b7e3..9e59dfb550 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1893,7 +1893,7 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
/* Must be non-NULL or bdrv_getlength() would have failed */
assert(bs->drv);
- if (!bs->drv->bdrv_co_get_block_status && !bs->drv->bdrv_co_block_status) {
+ if (!bs->drv->bdrv_co_block_status) {
*pnum = bytes;
ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
if (offset + bytes == total_size) {
@@ -1911,40 +1911,9 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
/* Round out to request_alignment boundaries */
align = bs->bl.request_alignment;
- if (bs->drv->bdrv_co_get_block_status && align < BDRV_SECTOR_SIZE) {
- align = BDRV_SECTOR_SIZE;
- }
aligned_offset = QEMU_ALIGN_DOWN(offset, align);
aligned_bytes = ROUND_UP(offset + bytes, align) - aligned_offset;
- if (bs->drv->bdrv_co_get_block_status) {
- int count; /* sectors */
- int64_t longret;
-
- assert(QEMU_IS_ALIGNED(aligned_offset | aligned_bytes,
- BDRV_SECTOR_SIZE));
- /*
- * The contract allows us to return pnum smaller than bytes, even
- * if the next query would see the same status; we truncate the
- * request to avoid overflowing the driver's 32-bit interface.
- */
- longret = bs->drv->bdrv_co_get_block_status(
- bs, aligned_offset >> BDRV_SECTOR_BITS,
- MIN(INT_MAX, aligned_bytes) >> BDRV_SECTOR_BITS, &count,
- &local_file);
- if (longret < 0) {
- assert(INT_MIN <= longret);
- ret = longret;
- goto out;
- }
- if (longret & BDRV_BLOCK_OFFSET_VALID) {
- local_map = longret & BDRV_BLOCK_OFFSET_MASK;
- }
- ret = longret & ~BDRV_BLOCK_OFFSET_MASK;
- *pnum = count * BDRV_SECTOR_SIZE;
- goto refine;
- }
-
ret = bs->drv->bdrv_co_block_status(bs, want_zero, aligned_offset,
aligned_bytes, pnum, &local_map,
&local_file);
@@ -1963,7 +1932,6 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
*pnum = total_size - aligned_offset;
}
-refine:
/*
* The driver's result must be a multiple of request_alignment.
* Clamp pnum and adjust map to original request.
--
2.14.3
^ permalink raw reply related [flat|nested] 26+ messages in thread