* [PATCH] virtio_blk: add helper function to support mass of disks naming
@ 2012-03-28 6:54 Ren Mingxin
2012-03-28 10:58 ` Michael S. Tsirkin
0 siblings, 1 reply; 6+ messages in thread
From: Ren Mingxin @ 2012-03-28 6:54 UTC (permalink / raw)
To: Rusty Russell, Michael S. Tsirkin; +Cc: LKML
Hi,
The current virtblk's naming algorithm just supports 26^3
disks. If there are mass of virtblks(exceeding 26^3), there
will be disks with the same name.
According to "sd_format_disk_name()", I add function
"virtblk_name_format()" for virtblk to support mass of
disks.
Signed-off-by: Ren Mingxin <renmx@cn.fujitsu.com>
---
virtio_blk.c | 37 +++++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index c4a60ba..07b8bf9 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -374,6 +374,30 @@ static int init_vq(struct virtio_blk *vblk)
return err;
}
+static int virtblk_name_format(char *prefix, int index, char *buf, int
buflen)
+{
+ const int base = 'z' - 'a' + 1;
+ char *begin = buf + strlen(prefix);
+ char *begin = buf + strlen(prefix);
+ char *end = buf + buflen;
+ char *p;
+ int unit;
+
+ p = end - 1;
+ *p = '\0';
+ unit = base;
+ do {
+ if (p == begin)
+ return -EINVAL;
+ *--p = 'a' + (index % unit);
+ index = (index / unit) - 1;
+ } while (index >= 0);
+
+ memmove(begin, p, end - p);
+ memcpy(buf, prefix, strlen(prefix));
+
+ return 0;
+}
+
static int __devinit virtblk_probe(struct virtio_device *vdev)
{
struct virtio_blk *vblk;
@@ -442,18 +466,7 @@ static int __devinit virtblk_probe(struct
virtio_device *vdev)
q->queuedata = vblk;
- if (index < 26) {
- sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26);
- } else if (index < (26 + 1) * 26) {
- sprintf(vblk->disk->disk_name, "vd%c%c",
- 'a' + index / 26 - 1, 'a' + index % 26);
- } else {
- const unsigned int m1 = (index / 26 - 1) / 26 - 1;
- const unsigned int m2 = (index / 26 - 1) % 26;
- const unsigned int m3 = index % 26;
- sprintf(vblk->disk->disk_name, "vd%c%c%c",
- 'a' + m1, 'a' + m2, 'a' + m3);
- }
+ virtblk_name_format("vd", index, vblk->disk->disk_name,
DISK_NAME_LEN);
vblk->disk->major = major;
vblk->disk->first_minor = index_to_minor(index);
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] virtio_blk: add helper function to support mass of disks naming
2012-03-28 6:54 [PATCH] virtio_blk: add helper function to support mass of disks naming Ren Mingxin
@ 2012-03-28 10:58 ` Michael S. Tsirkin
2012-03-29 4:40 ` Rusty Russell
2012-03-29 5:36 ` Ren Mingxin
0 siblings, 2 replies; 6+ messages in thread
From: Michael S. Tsirkin @ 2012-03-28 10:58 UTC (permalink / raw)
To: Ren Mingxin
Cc: Rusty Russell, LKML, Tejun Heo, jens.axboe, kvm, virtualization,
linux-scsi
On Wed, Mar 28, 2012 at 02:54:43PM +0800, Ren Mingxin wrote:
> Hi,
>
> The current virtblk's naming algorithm just supports 26^3
> disks. If there are mass of virtblks(exceeding 26^3), there
> will be disks with the same name.
>
> According to "sd_format_disk_name()", I add function
> "virtblk_name_format()" for virtblk to support mass of
> disks.
>
> Signed-off-by: Ren Mingxin <renmx@cn.fujitsu.com>
Nod. This is basically what 3e1a7ff8a0a7b948f2684930166954f9e8e776fe
did. Except, maybe we should move this function into block core
instead of duplicating it? Where would be a good place to put it?
Jens, care to comment?
> ---
> virtio_blk.c | 37 +++++++++++++++++++++++++------------
> 1 file changed, 25 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index c4a60ba..07b8bf9 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -374,6 +374,30 @@ static int init_vq(struct virtio_blk *vblk)
> return err;
> }
>
> +static int virtblk_name_format(char *prefix, int index, char *buf,
> int buflen)
> +{
> + const int base = 'z' - 'a' + 1;
> + char *begin = buf + strlen(prefix);
> + char *begin = buf + strlen(prefix);
> + char *end = buf + buflen;
> + char *p;
> + int unit;
> +
> + p = end - 1;
> + *p = '\0';
> + unit = base;
> + do {
> + if (p == begin)
> + return -EINVAL;
> + *--p = 'a' + (index % unit);
> + index = (index / unit) - 1;
> + } while (index >= 0);
> +
> + memmove(begin, p, end - p);
> + memcpy(buf, prefix, strlen(prefix));
> +
> + return 0;
> +}
> +
> static int __devinit virtblk_probe(struct virtio_device *vdev)
> {
> struct virtio_blk *vblk;
> @@ -442,18 +466,7 @@ static int __devinit virtblk_probe(struct
> virtio_device *vdev)
>
> q->queuedata = vblk;
>
> - if (index < 26) {
> - sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26);
> - } else if (index < (26 + 1) * 26) {
> - sprintf(vblk->disk->disk_name, "vd%c%c",
> - 'a' + index / 26 - 1, 'a' + index % 26);
> - } else {
> - const unsigned int m1 = (index / 26 - 1) / 26 - 1;
> - const unsigned int m2 = (index / 26 - 1) % 26;
> - const unsigned int m3 = index % 26;
> - sprintf(vblk->disk->disk_name, "vd%c%c%c",
> - 'a' + m1, 'a' + m2, 'a' + m3);
> - }
> + virtblk_name_format("vd", index, vblk->disk->disk_name,
> DISK_NAME_LEN);
>
> vblk->disk->major = major;
> vblk->disk->first_minor = index_to_minor(index);
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] virtio_blk: add helper function to support mass of disks naming
2012-03-28 10:58 ` Michael S. Tsirkin
@ 2012-03-29 4:40 ` Rusty Russell
2012-03-29 5:36 ` Ren Mingxin
1 sibling, 0 replies; 6+ messages in thread
From: Rusty Russell @ 2012-03-29 4:40 UTC (permalink / raw)
To: Michael S. Tsirkin, Ren Mingxin
Cc: LKML, Tejun Heo, jens.axboe, kvm, virtualization, linux-scsi
On Wed, 28 Mar 2012 12:58:21 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Wed, Mar 28, 2012 at 02:54:43PM +0800, Ren Mingxin wrote:
> > Hi,
> >
> > The current virtblk's naming algorithm just supports 26^3
> > disks. If there are mass of virtblks(exceeding 26^3), there
> > will be disks with the same name.
> >
> > According to "sd_format_disk_name()", I add function
> > "virtblk_name_format()" for virtblk to support mass of
> > disks.
> >
> > Signed-off-by: Ren Mingxin <renmx@cn.fujitsu.com>
>
> Nod. This is basically what 3e1a7ff8a0a7b948f2684930166954f9e8e776fe
> did. Except, maybe we should move this function into block core
> instead of duplicating it? Where would be a good place to put it?
> Jens, care to comment?
Indeed.
Cheers,
Rusty.
--
How could I marry someone with more hair than me? http://baldalex.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] virtio_blk: add helper function to support mass of disks naming
2012-03-28 10:58 ` Michael S. Tsirkin
2012-03-29 4:40 ` Rusty Russell
@ 2012-03-29 5:36 ` Ren Mingxin
2012-03-29 12:03 ` Jens Axboe
1 sibling, 1 reply; 6+ messages in thread
From: Ren Mingxin @ 2012-03-29 5:36 UTC (permalink / raw)
To: Michael S. Tsirkin, jens.axboe
Cc: Rusty Russell, LKML, Tejun Heo, kvm, virtualization, linux-scsi
On 03/28/2012 06:58 PM, Michael S. Tsirkin wrote:
> On Wed, Mar 28, 2012 at 02:54:43PM +0800, Ren Mingxin wrote:
>> Hi,
>>
>> The current virtblk's naming algorithm just supports 26^3
>> disks. If there are mass of virtblks(exceeding 26^3), there
>> will be disks with the same name.
>>
>> According to "sd_format_disk_name()", I add function
>> "virtblk_name_format()" for virtblk to support mass of
>> disks.
>>
>> Signed-off-by: Ren Mingxin<renmx@cn.fujitsu.com>
> Nod. This is basically what 3e1a7ff8a0a7b948f2684930166954f9e8e776fe
> did. Except, maybe we should move this function into block core
> instead of duplicating it? Where would be a good place to put it?
Yes, this was also what I thought.
How about placing the "sd_format_disk_name()"
as "disk_name_format()" into "block/genhd.c"
("include/linux/genhd.h")?
Thanks.
Ren
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] virtio_blk: add helper function to support mass of disks naming
2012-03-29 5:36 ` Ren Mingxin
@ 2012-03-29 12:03 ` Jens Axboe
2012-03-29 12:46 ` Michael S. Tsirkin
0 siblings, 1 reply; 6+ messages in thread
From: Jens Axboe @ 2012-03-29 12:03 UTC (permalink / raw)
To: Ren Mingxin
Cc: Michael S. Tsirkin, Rusty Russell, LKML, Tejun Heo, kvm,
virtualization, linux-scsi
On 03/29/2012 07:36 AM, Ren Mingxin wrote:
> On 03/28/2012 06:58 PM, Michael S. Tsirkin wrote:
>> On Wed, Mar 28, 2012 at 02:54:43PM +0800, Ren Mingxin wrote:
>>> Hi,
>>>
>>> The current virtblk's naming algorithm just supports 26^3
>>> disks. If there are mass of virtblks(exceeding 26^3), there
>>> will be disks with the same name.
>>>
>>> According to "sd_format_disk_name()", I add function
>>> "virtblk_name_format()" for virtblk to support mass of
>>> disks.
>>>
>>> Signed-off-by: Ren Mingxin<renmx@cn.fujitsu.com>
>> Nod. This is basically what 3e1a7ff8a0a7b948f2684930166954f9e8e776fe
>> did. Except, maybe we should move this function into block core
>> instead of duplicating it? Where would be a good place to put it?
>
> Yes, this was also what I thought.
>
> How about placing the "sd_format_disk_name()"
> as "disk_name_format()" into "block/genhd.c"
> ("include/linux/genhd.h")?
Yes, that sounds like the appropriate solution (and name, and where to
put it).
--
Jens Axboe
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] virtio_blk: add helper function to support mass of disks naming
2012-03-29 12:03 ` Jens Axboe
@ 2012-03-29 12:46 ` Michael S. Tsirkin
0 siblings, 0 replies; 6+ messages in thread
From: Michael S. Tsirkin @ 2012-03-29 12:46 UTC (permalink / raw)
To: Jens Axboe
Cc: Ren Mingxin, Rusty Russell, LKML, Tejun Heo, kvm, virtualization,
linux-scsi
On Thu, Mar 29, 2012 at 02:03:55PM +0200, Jens Axboe wrote:
> On 03/29/2012 07:36 AM, Ren Mingxin wrote:
> > On 03/28/2012 06:58 PM, Michael S. Tsirkin wrote:
> >> On Wed, Mar 28, 2012 at 02:54:43PM +0800, Ren Mingxin wrote:
> >>> Hi,
> >>>
> >>> The current virtblk's naming algorithm just supports 26^3
> >>> disks. If there are mass of virtblks(exceeding 26^3), there
> >>> will be disks with the same name.
> >>>
> >>> According to "sd_format_disk_name()", I add function
> >>> "virtblk_name_format()" for virtblk to support mass of
> >>> disks.
> >>>
> >>> Signed-off-by: Ren Mingxin<renmx@cn.fujitsu.com>
> >> Nod. This is basically what 3e1a7ff8a0a7b948f2684930166954f9e8e776fe
> >> did. Except, maybe we should move this function into block core
> >> instead of duplicating it? Where would be a good place to put it?
> >
> > Yes, this was also what I thought.
> >
> > How about placing the "sd_format_disk_name()"
> > as "disk_name_format()" into "block/genhd.c"
> > ("include/linux/genhd.h")?
>
> Yes, that sounds like the appropriate solution (and name, and where to
> put it).
OK, once this is posted I'll get your ack and
queue for 3.4 with other virtio fixups.
> --
> Jens Axboe
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-03-29 12:46 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-03-28 6:54 [PATCH] virtio_blk: add helper function to support mass of disks naming Ren Mingxin
2012-03-28 10:58 ` Michael S. Tsirkin
2012-03-29 4:40 ` Rusty Russell
2012-03-29 5:36 ` Ren Mingxin
2012-03-29 12:03 ` Jens Axboe
2012-03-29 12:46 ` Michael S. Tsirkin
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox