Tejun Heo <htejun@xxxxxxxxx> wrote:
> Elias Oltmanns wrote:
>> Tejun Heo <htejun@xxxxxxxxx> wrote:
[...]
>>> How about something like the following?
>>>
>>> * In park_store: set dev->unpark_timeout, kick and wake up EH.
>>>
>>> * In park EH action: until the latest of all unpark_timeout are
>>> passed, park all drives whose unpark_timeout is in future. When
>>> none of the drives needs to be parked (all timers expired), the
>>> action completes.
>>>
>>> * There probably needs to be a flag to indicate that the timeout is
>>> valid; otherwise, we could get spurious head unparking after jiffies
>>> wraps (or maybe just use jiffies_64?).
>>>
>>> With something like the above, the interface is cleanly per-dev and we
>>> wouldn't need -1/-2 special cases. The implementation is still
>>> per-port but we can change that later without modifying userland
>>> interface.
>>
>> First of all, we cannot do a proper per-dev implementation internally.
>
> Not yet but I think we should move toward per-queue EH which will
> enable fine-grained exception handling like this. Such approach would
> also help things like ATAPI CHECK_SENSE behind PMP. I think it's
> better to define the interface which suits the problem best rather
> than reflects the current implementation.
Does the following patch look like what you've had in mind (still
applies to next-20080903)?
Regards,
Elias
Signed-off-by: Elias Oltmanns <eo@xxxxxxxxxxxxxx>
---
drivers/ata/ahci.c | 1
drivers/ata/libata-eh.c | 89 ++++++++++++++++++++++++++++++++++++-
drivers/ata/libata-scsi.c | 109 +++++++++++++++++++++++++++++++++++++++++++++
drivers/ata/libata.h | 1
include/linux/libata.h | 12 ++++-
5 files changed, 209 insertions(+), 3 deletions(-)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index c729e69..9539050 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -316,6 +316,7 @@ static struct device_attribute *ahci_shost_attrs[] = {
static struct device_attribute *ahci_sdev_attrs[] = {
&dev_attr_sw_activity,
+ &dev_attr_unload_heads,
NULL
};
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index bd0b2bc..c1a4060 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2447,6 +2447,79 @@ int ata_eh_reset(struct ata_link *link, int classify,
goto retry;
}
+static unsigned long ata_eh_park_devs(struct ata_port *ap)
+{
+ struct ata_link *link;
+ struct ata_device *dev;
+ struct ata_taskfile tf;
+ unsigned int err_mask;
+ unsigned long deadline = jiffies;
+
+ ata_port_for_each_link(link, ap) {
+ ata_link_for_each_dev(dev, link) {
+ struct ata_eh_context *ehc = &link->eh_context;
+ struct ata_eh_info *ehi = &link->eh_info;
+
+ if (dev->class != ATA_DEV_ATA ||
+ dev->flags & ATA_DFLAG_NO_UNLOAD)
+ continue;
+
+ if (ehc->i.dev_action[dev->devno] & ATA_EH_PARK ||
+ ehi->dev_action[dev->devno] & ATA_EH_PARK) {
+ unsigned long tmp = dev->unpark_deadline;
+
+ if (time_before(deadline, tmp))
+ deadline = tmp;
+ else if (time_before_eq(tmp, jiffies))
+ continue;
+ }
+
+ if (ehc->did_unload_mask & (1 << dev->devno))
+ continue;
+
+ ata_tf_init(dev, &tf);
+ tf.command = ATA_CMD_IDLEIMMEDIATE;
+ tf.feature = 0x44;
+ tf.lbal = 0x4c;
+ tf.lbam = 0x4e;
+ tf.lbah = 0x55;
+ tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
+ tf.protocol |= ATA_PROT_NODATA;
+ err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE,
+ NULL, 0, 0);
+ if (err_mask || tf.lbal != 0xc4)
+ ata_dev_printk(dev, KERN_ERR,
+ "head unload failed!\n");
+ else
+ ehc->did_unload_mask |= 1 << dev->devno;
+ }
+ }
+
+ return deadline;
+}
+
+static void ata_eh_unpark_devs(struct ata_port *ap)
+{
+ struct ata_link *link;
+ struct ata_device *dev;
+ struct ata_taskfile tf;
+
+ ata_port_for_each_link(link, ap) {
+ ata_link_for_each_dev(dev, link) {
+ struct ata_eh_context *ehc = &link->eh_context;
+
+ if (!(ehc->did_unload_mask & (1 << dev->devno)))
+ continue;
+
+ ata_tf_init(dev, &tf);
+ tf.command = ATA_CMD_CHK_POWER;
+ tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
+ tf.protocol |= ATA_PROT_NODATA;
+ ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
+ }
+ }
+}
+
static int ata_eh_revalidate_and_attach(struct ata_link *link,
struct ata_device **r_failed_dev)
{
@@ -2754,9 +2827,10 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
{
struct ata_link *link;
struct ata_device *dev;
+ DEFINE_WAIT(wait);
int nr_failed_devs;
int rc;
- unsigned long flags;
+ unsigned long flags, deadline;
DPRINTK("ENTER\n");
@@ -2830,6 +2904,19 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
}
}
+ do {
+ unsigned long now;
+
+ deadline = ata_eh_park_devs(ap);
+ now = jiffies;
+ if (time_before_eq(deadline, now))
+ break;
+ prepare_to_wait(&ata_scsi_park_wq, &wait, TASK_UNINTERRUPTIBLE);
+ deadline = schedule_timeout_uninterruptible(deadline - now);
+ } while (deadline);
+ finish_wait(&ata_scsi_park_wq, &wait);
+ ata_eh_unpark_devs(ap);
+
/* the rest */
ata_port_for_each_link(link, ap) {
struct ata_eh_context *ehc = &link->eh_context;
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 4d066ad..45fb70c 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -55,6 +55,8 @@
static DEFINE_SPINLOCK(ata_scsi_rbuf_lock);
static u8 ata_scsi_rbuf[ATA_SCSI_RBUF_SIZE];
+DECLARE_WAIT_QUEUE_HEAD(ata_scsi_park_wq);
+
typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc);
static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
@@ -183,6 +185,104 @@ DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
ata_scsi_lpm_show, ata_scsi_lpm_put);
EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
+static ssize_t ata_scsi_park_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(device);
+ struct ata_port *ap;
+ struct ata_link *link;
+ struct ata_device *dev;
+ unsigned long flags;
+ unsigned int uninitialized_var(msecs);
+ int rc = 0;
+
+ ap = ata_shost_to_port(sdev->host);
+
+ spin_lock_irqsave(ap->lock, flags);
+ dev = ata_scsi_find_dev(ap, sdev);
+ if (!dev) {
+ rc = -ENODEV;
+ goto unlock;
+ }
+ if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
+ rc = -EOPNOTSUPP;
+ goto unlock;
+ }
+
+ link = dev->link;
+ if (((ap->pflags & ATA_PFLAG_EH_IN_PROGRESS &&
+ (link->eh_context.i.dev_action[dev->devno] & ATA_EH_PARK ||
+ link->eh_info.dev_action[dev->devno] & ATA_EH_PARK)) ||
+ (ap->pflags & ATA_PFLAG_EH_PENDING &&
+ link->eh_info.dev_action[dev->devno])) &&
+ time_after(dev->unpark_deadline, jiffies))
+ msecs = jiffies_to_msecs(dev->unpark_deadline - jiffies);
+ else
+ msecs = 0;
+
+unlock:
+ spin_unlock_irq(ap->lock);
+
+ return rc ? rc : snprintf(buf, 20, "%u\n", msecs);
+}
+
+static ssize_t ata_scsi_park_store(struct device *device,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct scsi_device *sdev = to_scsi_device(device);
+ struct ata_port *ap;
+ struct ata_device *dev;
+ long int input;
+ unsigned long flags;
+ int rc;
+
+ rc = strict_strtol(buf, 10, &input);
+ if (rc || input < -2 || input > ATA_TMOUT_MAX_PARK)
+ return -EINVAL;
+
+ ap = ata_shost_to_port(sdev->host);
+
+ spin_lock_irqsave(ap->lock, flags);
+ dev = ata_scsi_find_dev(ap, sdev);
+ if (unlikely(!dev)) {
+ rc = -ENODEV;
+ goto unlock;
+ }
+ if (dev->class != ATA_DEV_ATA) {
+ rc = -EOPNOTSUPP;
+ goto unlock;
+ }
+
+ if (input >= 0) {
+ if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
+ rc = -EOPNOTSUPP;
+ goto unlock;
+ }
+
+ dev->unpark_deadline = ata_deadline(jiffies, input);
+ dev->link->eh_info.dev_action[dev->devno] |= ATA_EH_PARK;
+ ata_port_schedule_eh(ap);
+ wake_up_all(&ata_scsi_park_wq);
+ } else {
+ switch (input) {
+ case -1:
+ dev->flags &= ~ATA_DFLAG_NO_UNLOAD;
+ break;
+ case -2:
+ dev->flags |= ATA_DFLAG_NO_UNLOAD;
+ break;
+ }
+ }
+unlock:
+ spin_unlock_irqrestore(ap->lock, flags);
+
+ return rc ? rc : len;
+}
+DEVICE_ATTR(unload_heads, S_IRUGO | S_IWUSR,
+ ata_scsi_park_show, ata_scsi_park_store);
+EXPORT_SYMBOL_GPL(dev_attr_unload_heads);
+
static void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
{
cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
@@ -269,6 +369,12 @@ DEVICE_ATTR(sw_activity, S_IWUGO | S_IRUGO, ata_scsi_activity_show,
ata_scsi_activity_store);
EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
+struct device_attribute *ata_common_sdev_attrs[] = {
+ &dev_attr_unload_heads,
+ NULL
+};
+EXPORT_SYMBOL_GPL(ata_common_sdev_attrs);
+
static void ata_scsi_invalid_field(struct scsi_cmnd *cmd,
void (*done)(struct scsi_cmnd *))
{
@@ -954,6 +1060,9 @@ static int atapi_drain_needed(struct request *rq)
static int ata_scsi_dev_config(struct scsi_device *sdev,
struct ata_device *dev)
{
+ if (!ata_id_has_unload(dev->id))
+ dev->flags |= ATA_DFLAG_NO_UNLOAD;
+
/* configure max sectors */
blk_queue_max_sectors(sdev->request_queue, dev->max_sectors);
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 24f5005..3869e6a 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -148,6 +148,7 @@ extern void ata_scsi_hotplug(struct work_struct *work);
extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
extern void ata_scsi_dev_rescan(struct work_struct *work);
extern int ata_bus_probe(struct ata_port *ap);
+extern wait_queue_head_t ata_scsi_park_wq;
/* libata-eh.c */
extern unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 225bfc5..71c6a42 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -146,6 +146,7 @@ enum {
ATA_DFLAG_SPUNDOWN = (1 << 14), /* XXX: for spindown_compat */
ATA_DFLAG_SLEEPING = (1 << 15), /* device is sleeping */
ATA_DFLAG_DUBIOUS_XFER = (1 << 16), /* data transfer not verified */
+ ATA_DFLAG_NO_UNLOAD = (1 << 17), /* device doesn't support unload */
ATA_DFLAG_INIT_MASK = (1 << 24) - 1,
ATA_DFLAG_DETACH = (1 << 24),
@@ -244,6 +245,7 @@ enum {
ATA_TMOUT_BOOT = 30000, /* heuristic */
ATA_TMOUT_BOOT_QUICK = 7000, /* heuristic */
ATA_TMOUT_INTERNAL_QUICK = 5000,
+ ATA_TMOUT_MAX_PARK = 30000,
/* FIXME: GoVault needs 2s but we can't afford that without
* parallel probing. 800ms is enough for iVDR disk
@@ -319,8 +321,9 @@ enum {
ATA_EH_RESET = ATA_EH_SOFTRESET | ATA_EH_HARDRESET,
ATA_EH_ENABLE_LINK = (1 << 3),
ATA_EH_LPM = (1 << 4), /* link power management action */
+ ATA_EH_PARK = (1 << 5), /* unload heads and stop I/O */
- ATA_EH_PERDEV_MASK = ATA_EH_REVALIDATE,
+ ATA_EH_PERDEV_MASK = ATA_EH_REVALIDATE | ATA_EH_PARK,
/* ata_eh_info->flags */
ATA_EHI_HOTPLUGGED = (1 << 0), /* could have been hotplugged */
@@ -452,6 +455,7 @@ enum link_pm {
MEDIUM_POWER,
};
extern struct device_attribute dev_attr_link_power_management_policy;
+extern struct device_attribute dev_attr_unload_heads;
extern struct device_attribute dev_attr_em_message_type;
extern struct device_attribute dev_attr_em_message;
extern struct device_attribute dev_attr_sw_activity;
@@ -564,6 +568,7 @@ struct ata_device {
/* n_sector is used as CLEAR_OFFSET, read comment above CLEAR_OFFSET */
u64 n_sectors; /* size of device, if ATA */
unsigned int class; /* ATA_DEV_xxx */
+ unsigned long unpark_deadline;
u8 pio_mode;
u8 dma_mode;
@@ -621,6 +626,7 @@ struct ata_eh_context {
[ATA_EH_CMD_TIMEOUT_TABLE_SIZE];
unsigned int classes[ATA_MAX_DEVICES];
unsigned int did_probe_mask;
+ unsigned int did_unload_mask;
unsigned int saved_ncq_enabled;
u8 saved_xfer_mode[ATA_MAX_DEVICES];
/* timestamp for the last reset attempt or success */
@@ -1098,6 +1104,7 @@ extern void ata_std_error_handler(struct ata_port *ap);
*/
extern const struct ata_port_operations ata_base_port_ops;
extern const struct ata_port_operations sata_port_ops;
+extern struct device_attribute *ata_common_sdev_attrs[];
#define ATA_BASE_SHT(drv_name) \
.module = THIS_MODULE, \
@@ -1112,7 +1119,8 @@ extern const struct ata_port_operations sata_port_ops;
.proc_name = drv_name, \
.slave_configure = ata_scsi_slave_config, \
.slave_destroy = ata_scsi_slave_destroy, \
- .bios_param = ata_std_bios_param
+ .bios_param = ata_std_bios_param, \
+ .sdev_attrs = ata_common_sdev_attrs
#define ATA_NCQ_SHT(drv_name) \
ATA_BASE_SHT(drv_name), \
--
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