| Message ID | 20221021053809.237651-3-damien.lemoal@opensource.wdc.com |
|---|---|
| State | New |
| Headers | show |
| Series | Improve libata support for FUA | expand |
On 10/21/22 07:38, Damien Le Moal wrote: > From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com> > > Currently, the libata.fua parameter isn't runtime-writable, so a > system restart is required in order to toggle it. > This unnecessarily complicates testing how drives behave with FUA on and > off. > > Let's make this parameter R/W instead, like many others in the kernel. > > Example usage: > Disable the parameter: > echo 0 >/sys/module/libata/parameters/fua > > Revalidate disk cache settings: > F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F > > [Damien] > Enabling fua support by setting libata.fua to 1 will have no effect if > the libata module is loaded with libata.force=[ID]nofua, which disables > fua support for the ata device(s) identified with ID or all ata devices > if no ID is specified. > > Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> > Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> > --- > drivers/ata/libata-core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c > index 6008f7ed1c42..1bb9616b10d9 100644 > --- a/drivers/ata/libata-core.c > +++ b/drivers/ata/libata-core.c > @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444); > MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])"); > > int libata_fua = 0; > -module_param_named(fua, libata_fua, int, 0444); > +module_param_named(fua, libata_fua, int, 0644); > MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)"); > > static int ata_ignore_hpa; Hmm. I guess you'll need to revalidate the drive when changing that; but this can be done in a later patch. Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
On 10/21/22 15:21, Hannes Reinecke wrote: > On 10/21/22 07:38, Damien Le Moal wrote: >> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com> >> >> Currently, the libata.fua parameter isn't runtime-writable, so a >> system restart is required in order to toggle it. >> This unnecessarily complicates testing how drives behave with FUA on and >> off. >> >> Let's make this parameter R/W instead, like many others in the kernel. >> >> Example usage: >> Disable the parameter: >> echo 0 >/sys/module/libata/parameters/fua >> >> Revalidate disk cache settings: >> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F >> >> [Damien] >> Enabling fua support by setting libata.fua to 1 will have no effect if >> the libata module is loaded with libata.force=[ID]nofua, which disables >> fua support for the ata device(s) identified with ID or all ata devices >> if no ID is specified. >> >> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> >> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> >> --- >> drivers/ata/libata-core.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c >> index 6008f7ed1c42..1bb9616b10d9 100644 >> --- a/drivers/ata/libata-core.c >> +++ b/drivers/ata/libata-core.c >> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444); >> MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])"); >> >> int libata_fua = 0; >> -module_param_named(fua, libata_fua, int, 0444); >> +module_param_named(fua, libata_fua, int, 0644); >> MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)"); >> >> static int ata_ignore_hpa; > Hmm. I guess you'll need to revalidate the drive when changing that; but > this can be done in a later patch. Well, this is not sysfs, we cannot do this automatically easily... And thinking about it now that you mention it, going from fua=1 to fua=0 can actually cause problems. The reverse not, since scsi side would still see fua=0 until revalidation. So... Unless we find a way to link the param write to reavlidation, we should actually not allow this. Maciej ? Thoughts ? > > Reviewed-by: Hannes Reinecke <hare@suse.de> > > Cheers, > > Hannes
On 10/21/22 15:50, Damien Le Moal wrote: > On 10/21/22 15:21, Hannes Reinecke wrote: >> On 10/21/22 07:38, Damien Le Moal wrote: >>> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com> >>> >>> Currently, the libata.fua parameter isn't runtime-writable, so a >>> system restart is required in order to toggle it. >>> This unnecessarily complicates testing how drives behave with FUA on and >>> off. >>> >>> Let's make this parameter R/W instead, like many others in the kernel. >>> >>> Example usage: >>> Disable the parameter: >>> echo 0 >/sys/module/libata/parameters/fua >>> >>> Revalidate disk cache settings: >>> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F >>> >>> [Damien] >>> Enabling fua support by setting libata.fua to 1 will have no effect if >>> the libata module is loaded with libata.force=[ID]nofua, which disables >>> fua support for the ata device(s) identified with ID or all ata devices >>> if no ID is specified. >>> >>> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> >>> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> >>> --- >>> drivers/ata/libata-core.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c >>> index 6008f7ed1c42..1bb9616b10d9 100644 >>> --- a/drivers/ata/libata-core.c >>> +++ b/drivers/ata/libata-core.c >>> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444); >>> MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])"); >>> >>> int libata_fua = 0; >>> -module_param_named(fua, libata_fua, int, 0444); >>> +module_param_named(fua, libata_fua, int, 0644); >>> MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)"); >>> >>> static int ata_ignore_hpa; >> Hmm. I guess you'll need to revalidate the drive when changing that; but >> this can be done in a later patch. > > Well, this is not sysfs, we cannot do this automatically easily... > And thinking about it now that you mention it, going from fua=1 to fua=0 > can actually cause problems. The reverse not, since scsi side would still > see fua=0 until revalidation. > > So... Unless we find a way to link the param write to reavlidation, we > should actually not allow this. > Maciej ? Thoughts ? I looked at this a little more. We could define the operations (struct kernel_param_ops) manually together with the fua parameter declaration, but that would be really ugly... Given that we are switching to fua=1 by default, do you still need a dynamic argument ? I am now thinking that this patch should be dropped. > >> >> Reviewed-by: Hannes Reinecke <hare@suse.de> >> >> Cheers, >> >> Hannes >
On 10/21/22 10:00, Damien Le Moal wrote: > On 10/21/22 15:50, Damien Le Moal wrote: >> On 10/21/22 15:21, Hannes Reinecke wrote: >>> On 10/21/22 07:38, Damien Le Moal wrote: >>>> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com> >>>> >>>> Currently, the libata.fua parameter isn't runtime-writable, so a >>>> system restart is required in order to toggle it. >>>> This unnecessarily complicates testing how drives behave with FUA on and >>>> off. >>>> >>>> Let's make this parameter R/W instead, like many others in the kernel. >>>> >>>> Example usage: >>>> Disable the parameter: >>>> echo 0 >/sys/module/libata/parameters/fua >>>> >>>> Revalidate disk cache settings: >>>> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F >>>> >>>> [Damien] >>>> Enabling fua support by setting libata.fua to 1 will have no effect if >>>> the libata module is loaded with libata.force=[ID]nofua, which disables >>>> fua support for the ata device(s) identified with ID or all ata devices >>>> if no ID is specified. >>>> >>>> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> >>>> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> >>>> --- >>>> drivers/ata/libata-core.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c >>>> index 6008f7ed1c42..1bb9616b10d9 100644 >>>> --- a/drivers/ata/libata-core.c >>>> +++ b/drivers/ata/libata-core.c >>>> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444); >>>> MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])"); >>>> >>>> int libata_fua = 0; >>>> -module_param_named(fua, libata_fua, int, 0444); >>>> +module_param_named(fua, libata_fua, int, 0644); >>>> MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)"); >>>> >>>> static int ata_ignore_hpa; >>> Hmm. I guess you'll need to revalidate the drive when changing that; but >>> this can be done in a later patch. >> >> Well, this is not sysfs, we cannot do this automatically easily... >> And thinking about it now that you mention it, going from fua=1 to fua=0 >> can actually cause problems. The reverse not, since scsi side would still >> see fua=0 until revalidation. >> >> So... Unless we find a way to link the param write to reavlidation, we >> should actually not allow this. >> Maciej ? Thoughts ? > > I looked at this a little more. We could define the operations (struct > kernel_param_ops) manually together with the fua parameter declaration, > but that would be really ugly... > > Given that we are switching to fua=1 by default, do you still need a > dynamic argument ? I am now thinking that this patch should be dropped. > I'd kill it, and let users it handle via blacklist flags only. Cheers, Hannes
On 10/21/22 17:45, Hannes Reinecke wrote: > On 10/21/22 10:00, Damien Le Moal wrote: >> On 10/21/22 15:50, Damien Le Moal wrote: >>> On 10/21/22 15:21, Hannes Reinecke wrote: >>>> On 10/21/22 07:38, Damien Le Moal wrote: >>>>> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com> >>>>> >>>>> Currently, the libata.fua parameter isn't runtime-writable, so a >>>>> system restart is required in order to toggle it. >>>>> This unnecessarily complicates testing how drives behave with FUA on and >>>>> off. >>>>> >>>>> Let's make this parameter R/W instead, like many others in the kernel. >>>>> >>>>> Example usage: >>>>> Disable the parameter: >>>>> echo 0 >/sys/module/libata/parameters/fua >>>>> >>>>> Revalidate disk cache settings: >>>>> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F >>>>> >>>>> [Damien] >>>>> Enabling fua support by setting libata.fua to 1 will have no effect if >>>>> the libata module is loaded with libata.force=[ID]nofua, which disables >>>>> fua support for the ata device(s) identified with ID or all ata devices >>>>> if no ID is specified. >>>>> >>>>> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> >>>>> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> >>>>> --- >>>>> drivers/ata/libata-core.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c >>>>> index 6008f7ed1c42..1bb9616b10d9 100644 >>>>> --- a/drivers/ata/libata-core.c >>>>> +++ b/drivers/ata/libata-core.c >>>>> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444); >>>>> MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])"); >>>>> >>>>> int libata_fua = 0; >>>>> -module_param_named(fua, libata_fua, int, 0444); >>>>> +module_param_named(fua, libata_fua, int, 0644); >>>>> MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)"); >>>>> >>>>> static int ata_ignore_hpa; >>>> Hmm. I guess you'll need to revalidate the drive when changing that; but >>>> this can be done in a later patch. >>> >>> Well, this is not sysfs, we cannot do this automatically easily... >>> And thinking about it now that you mention it, going from fua=1 to fua=0 >>> can actually cause problems. The reverse not, since scsi side would still >>> see fua=0 until revalidation. >>> >>> So... Unless we find a way to link the param write to reavlidation, we >>> should actually not allow this. >>> Maciej ? Thoughts ? >> >> I looked at this a little more. We could define the operations (struct >> kernel_param_ops) manually together with the fua parameter declaration, >> but that would be really ugly... >> >> Given that we are switching to fua=1 by default, do you still need a >> dynamic argument ? I am now thinking that this patch should be dropped. >> > I'd kill it, and let users it handle via blacklist flags only. Yep, with the default set to 1 that is the goal. I kept the fua module parameter for backward compatibility, in case some setups out there use it. But the force=[ID]nofua or force=[ID]fua module parameters should be the preferred way to control this now. > > Cheers, > > Hannes
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 6008f7ed1c42..1bb9616b10d9 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444); MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])"); int libata_fua = 0; -module_param_named(fua, libata_fua, int, 0444); +module_param_named(fua, libata_fua, int, 0644); MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)"); static int ata_ignore_hpa;