| Message ID | 20230404182428.715140-10-nks@flawful.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add Command Duration Limits support | expand |
On Tue, Apr 04, 2023 at 08:24:14PM +0200, Niklas Cassel wrote: > From: Damien Le Moal <damien.lemoal@opensource.wdc.com> > > Add the sysfs scsi device attribute cdl_enable to allow a user to turn > enable or disable a device command duration limits feature. CDL is > disabled by default. This feature must be explicitly enabled by a user by > setting the cdl_enable attribute to 1. > > The new function scsi_cdl_enable() does not do anything beside setting > the cdl_enable field of struct scsi_device in the case of a (real) scsi > device (e.g. a SAS HDD). For ATA devices, the command duration limits > feature needs to be enabled/disabled using the ATA feature sub-page of > the control mode page. To do so, the scsi_cdl_enable() function checks > if this mode page is supported using scsi_mode_sense(). If it is, > scsi_mode_select() is used to enable and disable CDL. > > Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> > Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com> > Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> > --- > Documentation/ABI/testing/sysfs-block-device | 13 ++++ > drivers/scsi/scsi.c | 62 ++++++++++++++++++++ > drivers/scsi/scsi_sysfs.c | 31 ++++++++++ > include/scsi/scsi_device.h | 2 + > 4 files changed, 108 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device > index ee3610a25845..626d48ac504b 100644 > --- a/Documentation/ABI/testing/sysfs-block-device > +++ b/Documentation/ABI/testing/sysfs-block-device > @@ -104,3 +104,16 @@ Contact: linux-scsi@vger.kernel.org > Description: > (RO) Indicates if the device supports the command duration > limits feature found in some ATA and SCSI devices. > + > + > +What: /sys/block/*/device/cdl_enable > +Date: Mar, 2023 > +KernelVersion: v6.4 > +Contact: linux-scsi@vger.kernel.org > +Description: > + (RW) For a device supporting the command duration limits > + feature, write to the file to turn on or off the feature. > + By default this feature is turned off. > + Writing "1" to this file enables the use of command duration > + limits for read and write commands in the kernel and turns on > + the feature on the device. Writing "0" disables the feature. > diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c > index c03814ce23ca..c4bf99a842f3 100644 > --- a/drivers/scsi/scsi.c > +++ b/drivers/scsi/scsi.c > @@ -651,6 +651,68 @@ void scsi_cdl_check(struct scsi_device *sdev) > kfree(buf); > } > > +/** > + * scsi_cdl_enable - Enable or disable a SCSI device supports for Command > + * Duration Limits > + * @sdev: The target device > + * @enable: the target state > + */ > +int scsi_cdl_enable(struct scsi_device *sdev, bool enable) > +{ > + struct scsi_mode_data data; > + struct scsi_sense_hdr sshdr; > + struct scsi_vpd *vpd; > + bool is_ata = false; > + char buf[64]; > + int ret; > + > + if (!sdev->cdl_supported) > + return -EOPNOTSUPP; > + > + rcu_read_lock(); > + vpd = rcu_dereference(sdev->vpd_pg89); > + if (vpd) > + is_ata = true; > + rcu_read_unlock(); > + > + /* > + * For ATA devices, CDL needs to be enabled with a SET FEATURES command. > + */ > + if (is_ata) { > + char *buf_data; > + int len; > + > + ret = scsi_mode_sense(sdev, 0x08, 0x0a, 0xf2, buf, sizeof(buf), > + 5 * HZ, 3, &data, NULL); > + if (ret) > + return -EINVAL; > + > + /* Enable CDL using the ATA feature page */ > + len = min_t(size_t, sizeof(buf), > + data.length - data.header_length - > + data.block_descriptor_length); > + buf_data = buf + data.header_length + > + data.block_descriptor_length; > + if (enable) > + buf_data[4] = 0x02; > + else > + buf_data[4] = 0; > + > + ret = scsi_mode_select(sdev, 1, 0, buf_data, len, 5 * HZ, 3, > + &data, &sshdr); > + if (ret) { > + if (scsi_sense_valid(&sshdr)) > + scsi_print_sense_hdr(sdev, > + dev_name(&sdev->sdev_gendev), &sshdr); > + return ret; > + } > + } > + > + sdev->cdl_enable = enable; > + > + return 0; > +} > + > /** > * scsi_device_get - get an additional reference to a scsi_device > * @sdev: device to get a reference to > diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c > index 4994148e685b..9a54b2c0fee7 100644 > --- a/drivers/scsi/scsi_sysfs.c > +++ b/drivers/scsi/scsi_sysfs.c > @@ -1222,6 +1222,36 @@ static DEVICE_ATTR(queue_ramp_up_period, S_IRUGO | S_IWUSR, > sdev_show_queue_ramp_up_period, > sdev_store_queue_ramp_up_period); > > +static ssize_t sdev_show_cdl_enable(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct scsi_device *sdev = to_scsi_device(dev); > + > + return sysfs_emit(buf, "%d\n", (int)sdev->cdl_enable); > +} > + > +static ssize_t sdev_store_cdl_enable(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + int ret; > + bool v; > + > + if (!capable(CAP_SYS_ADMIN)) > + return -EACCES; CAP_SYS_ADMIN seems be too restrictive. NCQ PRIO (ncq_prio_enable) does not require CAP_SYS_ADMIN. Since NCQ PRIO and CDL are mutually exclusive a user should be able to toggle both features. Thanks, Igor > + > + if (kstrtobool(buf, &v)) > + return -EINVAL; > + > + ret = scsi_cdl_enable(to_scsi_device(dev), v); > + if (ret) > + return ret; > + > + return count; > +} > +static DEVICE_ATTR(cdl_enable, S_IRUGO | S_IWUSR, > + sdev_show_cdl_enable, sdev_store_cdl_enable); > + > static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj, > struct attribute *attr, int i) > { > @@ -1302,6 +1332,7 @@ static struct attribute *scsi_sdev_attrs[] = { > #endif > &dev_attr_queue_ramp_up_period.attr, > &dev_attr_cdl_supported.attr, > + &dev_attr_cdl_enable.attr, > REF_EVT(media_change), > REF_EVT(inquiry_change_reported), > REF_EVT(capacity_change_reported), > diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h > index 6b8df9e253a0..b2cdb078b7bd 100644 > --- a/include/scsi/scsi_device.h > +++ b/include/scsi/scsi_device.h > @@ -219,6 +219,7 @@ struct scsi_device { > unsigned no_vpd_size:1; /* No VPD size reported in header */ > > unsigned cdl_supported:1; /* Command duration limits supported */ > + unsigned cdl_enable:1; /* Enable/disable Command duration limits */ > > unsigned int queue_stopped; /* request queue is quiesced */ > bool offline_already; /* Device offline message logged */ > @@ -367,6 +368,7 @@ extern void scsi_remove_device(struct scsi_device *); > extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh); > void scsi_attach_vpd(struct scsi_device *sdev); > void scsi_cdl_check(struct scsi_device *sdev); > +int scsi_cdl_enable(struct scsi_device *sdev, bool enable); > > extern struct scsi_device *scsi_device_from_queue(struct request_queue *q); > extern int __must_check scsi_device_get(struct scsi_device *); > -- > 2.39.2 >
On 4/5/23 04:28, Igor Pylypiv wrote: >> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c >> index 4994148e685b..9a54b2c0fee7 100644 >> --- a/drivers/scsi/scsi_sysfs.c >> +++ b/drivers/scsi/scsi_sysfs.c >> @@ -1222,6 +1222,36 @@ static DEVICE_ATTR(queue_ramp_up_period, S_IRUGO | S_IWUSR, >> sdev_show_queue_ramp_up_period, >> sdev_store_queue_ramp_up_period); >> >> +static ssize_t sdev_show_cdl_enable(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + struct scsi_device *sdev = to_scsi_device(dev); >> + >> + return sysfs_emit(buf, "%d\n", (int)sdev->cdl_enable); >> +} >> + >> +static ssize_t sdev_store_cdl_enable(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + int ret; >> + bool v; >> + >> + if (!capable(CAP_SYS_ADMIN)) >> + return -EACCES; > CAP_SYS_ADMIN seems be too restrictive. NCQ PRIO (ncq_prio_enable) does not > require CAP_SYS_ADMIN. Since NCQ PRIO and CDL are mutually exclusive a user > should be able to toggle both features. Indeed, we can have CDL be the same as NCQ prio. We can remove this SYS_CAP_ADMIN check.
diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device index ee3610a25845..626d48ac504b 100644 --- a/Documentation/ABI/testing/sysfs-block-device +++ b/Documentation/ABI/testing/sysfs-block-device @@ -104,3 +104,16 @@ Contact: linux-scsi@vger.kernel.org Description: (RO) Indicates if the device supports the command duration limits feature found in some ATA and SCSI devices. + + +What: /sys/block/*/device/cdl_enable +Date: Mar, 2023 +KernelVersion: v6.4 +Contact: linux-scsi@vger.kernel.org +Description: + (RW) For a device supporting the command duration limits + feature, write to the file to turn on or off the feature. + By default this feature is turned off. + Writing "1" to this file enables the use of command duration + limits for read and write commands in the kernel and turns on + the feature on the device. Writing "0" disables the feature. diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index c03814ce23ca..c4bf99a842f3 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -651,6 +651,68 @@ void scsi_cdl_check(struct scsi_device *sdev) kfree(buf); } +/** + * scsi_cdl_enable - Enable or disable a SCSI device supports for Command + * Duration Limits + * @sdev: The target device + * @enable: the target state + */ +int scsi_cdl_enable(struct scsi_device *sdev, bool enable) +{ + struct scsi_mode_data data; + struct scsi_sense_hdr sshdr; + struct scsi_vpd *vpd; + bool is_ata = false; + char buf[64]; + int ret; + + if (!sdev->cdl_supported) + return -EOPNOTSUPP; + + rcu_read_lock(); + vpd = rcu_dereference(sdev->vpd_pg89); + if (vpd) + is_ata = true; + rcu_read_unlock(); + + /* + * For ATA devices, CDL needs to be enabled with a SET FEATURES command. + */ + if (is_ata) { + char *buf_data; + int len; + + ret = scsi_mode_sense(sdev, 0x08, 0x0a, 0xf2, buf, sizeof(buf), + 5 * HZ, 3, &data, NULL); + if (ret) + return -EINVAL; + + /* Enable CDL using the ATA feature page */ + len = min_t(size_t, sizeof(buf), + data.length - data.header_length - + data.block_descriptor_length); + buf_data = buf + data.header_length + + data.block_descriptor_length; + if (enable) + buf_data[4] = 0x02; + else + buf_data[4] = 0; + + ret = scsi_mode_select(sdev, 1, 0, buf_data, len, 5 * HZ, 3, + &data, &sshdr); + if (ret) { + if (scsi_sense_valid(&sshdr)) + scsi_print_sense_hdr(sdev, + dev_name(&sdev->sdev_gendev), &sshdr); + return ret; + } + } + + sdev->cdl_enable = enable; + + return 0; +} + /** * scsi_device_get - get an additional reference to a scsi_device * @sdev: device to get a reference to diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 4994148e685b..9a54b2c0fee7 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1222,6 +1222,36 @@ static DEVICE_ATTR(queue_ramp_up_period, S_IRUGO | S_IWUSR, sdev_show_queue_ramp_up_period, sdev_store_queue_ramp_up_period); +static ssize_t sdev_show_cdl_enable(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct scsi_device *sdev = to_scsi_device(dev); + + return sysfs_emit(buf, "%d\n", (int)sdev->cdl_enable); +} + +static ssize_t sdev_store_cdl_enable(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + bool v; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if (kstrtobool(buf, &v)) + return -EINVAL; + + ret = scsi_cdl_enable(to_scsi_device(dev), v); + if (ret) + return ret; + + return count; +} +static DEVICE_ATTR(cdl_enable, S_IRUGO | S_IWUSR, + sdev_show_cdl_enable, sdev_store_cdl_enable); + static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj, struct attribute *attr, int i) { @@ -1302,6 +1332,7 @@ static struct attribute *scsi_sdev_attrs[] = { #endif &dev_attr_queue_ramp_up_period.attr, &dev_attr_cdl_supported.attr, + &dev_attr_cdl_enable.attr, REF_EVT(media_change), REF_EVT(inquiry_change_reported), REF_EVT(capacity_change_reported), diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 6b8df9e253a0..b2cdb078b7bd 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -219,6 +219,7 @@ struct scsi_device { unsigned no_vpd_size:1; /* No VPD size reported in header */ unsigned cdl_supported:1; /* Command duration limits supported */ + unsigned cdl_enable:1; /* Enable/disable Command duration limits */ unsigned int queue_stopped; /* request queue is quiesced */ bool offline_already; /* Device offline message logged */ @@ -367,6 +368,7 @@ extern void scsi_remove_device(struct scsi_device *); extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh); void scsi_attach_vpd(struct scsi_device *sdev); void scsi_cdl_check(struct scsi_device *sdev); +int scsi_cdl_enable(struct scsi_device *sdev, bool enable); extern struct scsi_device *scsi_device_from_queue(struct request_queue *q); extern int __must_check scsi_device_get(struct scsi_device *);