[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] Re: [PATCH 1/4] Add virtio disk identification support
From: |
john cooper |
Subject: |
[Qemu-devel] Re: [PATCH 1/4] Add virtio disk identification support |
Date: |
Fri, 04 Jun 2010 02:32:49 -0400 |
User-agent: |
Thunderbird 2.0.0.9 (X11/20071115) |
Anthony Liguori wrote:
> On 03/25/2010 12:32 AM, john cooper wrote:
>> Add virtio-blk device id (s/n) support via virtio request.
>> Remove artifacts of pci and ATA_IDENTIFY implementation
>> relative to prior versions.
>>
>> Signed-off-by: john cooper<address@hidden>
>> ---
>>
>> diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
>> index 9915840..358b0af 100644
>> --- a/hw/virtio-blk.c
>> +++ b/hw/virtio-blk.c
>> @@ -19,6 +19,8 @@
>> # include<scsi/sg.h>
>> #endif
>>
>> +#define min(a,b) ((a)< (b) ? (a) : (b))
>>
>
> We already have MIN().
>
>> +
>> typedef struct VirtIOBlock
>> {
>> VirtIODevice vdev;
>> @@ -28,6 +30,7 @@ typedef struct VirtIOBlock
>> QEMUBH *bh;
>> BlockConf *conf;
>> unsigned short sector_mask;
>> + char sn[BLOCK_SERIAL_STRLEN];
>> } VirtIOBlock;
>>
>> static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
>> @@ -317,6 +320,12 @@ static void
>> virtio_blk_handle_request(VirtIOBlockReq *req,
>> virtio_blk_handle_flush(req);
>> } else if (req->out->type& VIRTIO_BLK_T_SCSI_CMD) {
>> virtio_blk_handle_scsi(req);
>> + } else if (req->out->type& VIRTIO_BLK_T_GET_ID) {
>> + VirtIOBlock *s = req->dev;
>> +
>> + memcpy(req->elem.in_sg[0].iov_base, s->sn,
>> + min(req->elem.in_sg[0].iov_len, sizeof(s->sn)));
>> + virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
>> } else if (req->out->type& VIRTIO_BLK_T_OUT) {
>> qemu_iovec_init_external(&req->qiov,&req->elem.out_sg[1],
>> req->elem.out_num - 1);
>> @@ -496,6 +505,8 @@ VirtIODevice *virtio_blk_init(DeviceState *dev,
>> BlockConf *conf)
>> bdrv_guess_geometry(s->bs,&cylinders,&heads,&secs);
>> bdrv_set_geometry_hint(s->bs, cylinders, heads, secs);
>>
>> + strncpy(s->sn, drive_get_serial(s->bs), sizeof (s->sn));
>> +
>>
>
> Friends don't let friends use strncpy().
>
> This actually will result in a non-NULL terminated string if
> drive_get_serial() returns a string larger than s->sn. Use snprintf()
> instead.
That actually is the desired behavior here as a serial
string is of BLOCK_SERIAL_STRLEN bytes length maximum
and not assured to be nul terminated (legacy ATA convention).
snprintf() would cause us to lose the last string character
in the case the full BLOCK_SERIAL_STRLEN bytes were in use.
There are existing storage allocations of BLOCK_SERIAL_STRLEN + 1
in some cases but this appears as an internal convenience
and is not part of the serial string data.
-john
--
address@hidden