[Qemu-devel] [PATCH] qemu-io: Rework alloc command

[Qemu-devel] [PATCH] qemu-io: Rework alloc command

[Kevin Wolf]

The alloc command in qemu-io is mostly useless currently. Instead of doing a
single call to bdrv_is_allocated, we must call bdrv_is_allocated in a loop
until we have found out for each requested sector if it is allocated or not
(bdrv_is_allocated returns a number of sectors that are known to be in the same
state as the first one, but it is not required to include all of them)

This changes the output format of the alloc command so that a change to the
expected output of qemu-iotests 019 is necessary once this is included.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-io.c |   22 ++++++++++++++--------
 1 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/qemu-io.c b/qemu-io.c
index 6c35a07..f938575 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -1170,11 +1170,10 @@ static int
 alloc_f(int argc, char **argv)
 {
 	int64_t offset;
-	int nb_sectors;
+	int nb_sectors, remaining;
 	char s1[64];
-	int num;
+	int num, sum_alloc;
 	int ret;
-	const char *retstr;
 
 	offset = cvtnum(argv[1]);
 	if (offset & 0x1ff) {
@@ -1188,16 +1187,23 @@ alloc_f(int argc, char **argv)
 	else
 		nb_sectors = 1;
 
-	ret = bdrv_is_allocated(bs, offset >> 9, nb_sectors, &num);
+	remaining = nb_sectors;
+	sum_alloc = 0;
+	while (remaining) {
+		ret = bdrv_is_allocated(bs, offset >> 9, nb_sectors, &num);
+		remaining -= num;
+		if (ret) {
+			sum_alloc += num;
+		}
+	}
 
 	cvtstr(offset, s1, sizeof(s1));
 
-	retstr = ret ? "allocated" : "not allocated";
 	if (nb_sectors == 1)
-		printf("sector %s at offset %s\n", retstr, s1);
+		printf("sector allocated at offset %s\n", s1);
 	else
-		printf("%d/%d sectors %s at offset %s\n",
-			num, nb_sectors, retstr, s1);
+		printf("%d/%d sectors allocated at offset %s\n",
+			sum_alloc, nb_sectors, s1);
 	return 0;
 }
 
-- 
1.6.0.6

Re: [Qemu-devel] [PATCH] qemu-io: Rework alloc command

[Christoph Hellwig]

On Mon, Jul 20, 2009 at 04:48:43PM +0200, Kevin Wolf wrote:
> The alloc command in qemu-io is mostly useless currently. Instead of doing a
> single call to bdrv_is_allocated, we must call bdrv_is_allocated in a loop
> until we have found out for each requested sector if it is allocated or not
> (bdrv_is_allocated returns a number of sectors that are known to be in the same
> state as the first one, but it is not required to include all of them)
> 
> This changes the output format of the alloc command so that a change to the
> expected output of qemu-iotests 019 is necessary once this is included.

Looks good to me.  Can you post the corresponding qemu-iotests patch,
too?

Re: [Qemu-devel] [PATCH] qemu-io: Rework alloc command

[Kevin Wolf]

[-- Attachment #1: Type: text/plain, Size: 895 bytes --]

Christoph Hellwig schrieb:
> On Mon, Jul 20, 2009 at 04:48:43PM +0200, Kevin Wolf wrote:
>> The alloc command in qemu-io is mostly useless currently. Instead of doing a
>> single call to bdrv_is_allocated, we must call bdrv_is_allocated in a loop
>> until we have found out for each requested sector if it is allocated or not
>> (bdrv_is_allocated returns a number of sectors that are known to be in the same
>> state as the first one, but it is not required to include all of them)
>>
>> This changes the output format of the alloc command so that a change to the
>> expected output of qemu-iotests 019 is necessary once this is included.
> 
> Looks good to me.  Can you post the corresponding qemu-iotests patch,
> too?

I wanted to post it when the qemu-io change is in, but if you want to
apply it earlier (makes qcow2 and vmdk fail until the qemu-io patch is
committed), here is it.

Kevin

[-- Attachment #2: 0001-qemu-iotests-Fix-expected-result-for-019-after-qemu.patch --]
[-- Type: text/plain, Size: 969 bytes --]

>From 41f80a74b4177e5396dab7916f8f7b40a65cef07 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 21 Jul 2009 09:16:37 +0200
Subject: [PATCH] qemu-iotests: Fix expected result for 019 after qemu-io change

The output of the alloc command in qemu-io has changed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 019.out |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/019.out b/019.out
index f461f8b..9ac1a21 100644
--- a/019.out
+++ b/019.out
@@ -539,8 +539,8 @@ qemu-io> wrote 65536/65536 bytes at offset 4296146944
 qemu-io> No errors were found on the image.
 Checking if backing clusters are allocated when they shouldn't
 
-qemu-io> 128/128 sectors not allocated at offset 1 MiB
-qemu-io> qemu-io> 128/128 sectors not allocated at offset 4.001 GiB
+qemu-io> 0/128 sectors allocated at offset 1 MiB
+qemu-io> qemu-io> 0/128 sectors allocated at offset 4.001 GiB
 qemu-io> Reading
 
 === IO: pattern 0
-- 
1.6.0.6

Re: [Qemu-devel] [PATCH] qemu-io: Rework alloc command

[Christoph Hellwig]

On Tue, Jul 21, 2009 at 09:22:04AM +0200, Kevin Wolf wrote:
> I wanted to post it when the qemu-io change is in, but if you want to
> apply it earlier (makes qcow2 and vmdk fail until the qemu-io patch is
> committed), here is it.

Thanks, I've put it in now that the qemu-io change went in.