Bug 115351

Summary: redundant pointless messages
Product: IO/Storage Reporter: Jonathan (spamme)
Component: SCSIAssignee: linux-scsi (linux-scsi)
Status: NEW ---    
Severity: low CC: spamme
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: All Subsystem:
Regression: No Bisected commit-id:

Description Jonathan 2016-03-27 19:48:58 UTC 
First, why does it have to log "Very big device" 44 times on startup.
Second, Given the size of ALL modern hard drives an array of almost any size probably triggers this warning.  

Suggestion:  just get rid of this pointless message.  Maybe you should just always use 16, or maybe for future proofing go to 24 or 32. 

[    2.518621] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[    2.521082] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[    2.530614] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   31.160167] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   31.162414] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   39.091369] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   39.093872] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   45.880219] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   48.171378] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   54.069779] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   54.074579] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   54.077133] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   77.748461] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   77.759371] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   84.549201] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[   91.288396] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  104.879051] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  104.881052] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  118.411278] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  125.193326] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  125.194891] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  159.063910] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  159.067481] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  179.361285] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  179.364259] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  179.379481] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  199.666114] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  213.116560] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  213.118659] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  213.120798] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  213.123825] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  213.125164] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  233.471647] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  233.473467] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  251.053596] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  251.055879] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  251.057935] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  251.059881] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  257.699835] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  278.193261] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  326.820650] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  326.852786] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[  346.504500] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[ 1233.124007] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
Comment 1 d gilbert 2016-03-28 00:55:48 UTC 
On 16-03-27 03:48 PM, bugzilla-daemon@bugzilla.kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=115351
>
>              Bug ID: 115351
>             Summary: redundant pointless messages
>             Product: IO/Storage
>             Version: 2.5
>      Kernel Version: All
>            Hardware: All
>                  OS: Linux
>                Tree: Mainline
>              Status: NEW
>            Severity: low
>            Priority: P1
>           Component: SCSI
>            Assignee: linux-scsi@vger.kernel.org
>            Reporter: spamme@ecybernard.com
>          Regression: No
>
> First, why does it have to log "Very big device" 44 times on startup.
> Second, Given the size of ALL modern hard drives an array of almost any size
> probably triggers this warning.

That will only occur if this function:

static int sd_try_rc16_first(struct scsi_device *sdp)
{
         if (sdp->host->max_cmd_len < 16)
                 return 0;
         if (sdp->try_rc_10_first)
                 return 0;
         if (sdp->scsi_level > SCSI_SPC_2)
                 return 1;
         if (scsi_device_protection(sdp))
                 return 1;
         return 0;
}

returns zero and the disks in question have more than 2**32 - 1
logical blocks. [For 512 byte blocks that is 2 TiB, for 4096 byte
blocks that is 16 TiB.] Modern SCSI (SAS) disks should be reporting
SPC-3 or higher compliance as should virtual disks in any properly
configured array.

> Suggestion:  just get rid of this pointless message.  Maybe you should just
> always use 16, or maybe for future proofing go to 24 or 32.

The 2**64 logical block maximum in the READ CAPACITY(16) response
should be sufficient, for the time being.

Request: find out why sd_try_rc16_first() returns zero.

Doug Gilbert
Comment 2 Jonathan 2016-03-28 01:14:41 UTC 
clearly if 16 is enough for 2^64 then just get rid of the error message all together, and call it done.

I don't know why sd_try_rc16_first() returns zero.
I don't even know how to find out.

This is all the dmesg reveals:
[    2.520235] AAC0: kernel 7.5-0[32084] Jun 15 2015
[    2.520240] AAC0: monitor 7.5-0[32084]
[    2.520241] AAC0: bios 7.5-0[32084]
[    2.520243] AAC0: serial ########
[    2.520244] AAC0: Non-DASD support enabled.
[    2.520246] AAC0: 64bit support enabled.
[    2.520247] AAC0: 64 Bit DAC enabled
[    2.520524] scsi host4: aacraid
[    2.530234] scsi host5: pata_atiixp
[    2.530480] scsi 4:0:0:0: Direct-Access     ASR7168  Tardis           V1.0 PQ: 0 ANSI: 2
[    2.530631] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[    2.530687] sd 4:0:0:0: [sdc] 19503493120 512-byte logical blocks: (9.99 TB/9.08 TiB)
[    2.530697] sd 4:0:0:0: [sdc] Write Protect is off
[    2.530699] sd 4:0:0:0: [sdc] Mode Sense: 12 00 10 08
[    2.530706] sd 4:0:0:0: Attached scsi generic sg2 type 0
[    2.530730] sd 4:0:0:0: [sdc] Write cache: disabled, read cache: enabled, supports DPO and FUA
[    2.530891] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
[    2.531195] sd 4:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
Comment 3 Jonathan 2016-03-28 01:38:06 UTC 
 scsi 4:3:0:0: Wrong diagnostic page; asked for 7 got 0
I get bunches of these