Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 623a3128 authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
Browse files

[PATCH] libata: implement ata_dev_revalidate() 



ata_dev_revalidate() re-reads IDENTIFY PAGE of the given device and
makes sure it's the same device as the configured one.  Once it's
verified that it's the same device, @dev is configured according to
newly read IDENTIFY PAGE.  Note that revalidation currently doesn't
invoke transfer mode reconfiguration.

Criteria for 'same device'

* same class (of course)
* same model string
* same serial string
* if ATA, same n_sectors (to catch geometry parameter changes)

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 4c2d721a

drivers/scsi/libata-core.c

+115 −0
Original line number Diff line number Diff line
@@ -2345,6 +2345,120 @@ int ata_drive_probe_reset(struct ata_port *ap, ata_probeinit_fn_t probeinit, 
	return rc;

}



/**

 *	ata_dev_same_device - Determine whether new ID matches configured device

 *	@ap: port on which the device to compare against resides

 *	@dev: device to compare against

 *	@new_class: class of the new device

 *	@new_id: IDENTIFY page of the new device

 *

 *	Compare @new_class and @new_id against @dev and determine

 *	whether @dev is the device indicated by @new_class and

 *	@new_id.

 *

 *	LOCKING:

 *	None.

 *

 *	RETURNS:

 *	1 if @dev matches @new_class and @new_id, 0 otherwise.

 */

static int ata_dev_same_device(struct ata_port *ap, struct ata_device *dev,

			       unsigned int new_class, const u16 *new_id)

{

	const u16 *old_id = dev->id;

	unsigned char model[2][41], serial[2][21];

	u64 new_n_sectors;



	if (dev->class != new_class) {

		printk(KERN_INFO

		       "ata%u: dev %u class mismatch %d != %d\n",

		       ap->id, dev->devno, dev->class, new_class);

		return 0;

	}



	ata_id_c_string(old_id, model[0], ATA_ID_PROD_OFS, sizeof(model[0]));

	ata_id_c_string(new_id, model[1], ATA_ID_PROD_OFS, sizeof(model[1]));

	ata_id_c_string(old_id, serial[0], ATA_ID_SERNO_OFS, sizeof(serial[0]));

	ata_id_c_string(new_id, serial[1], ATA_ID_SERNO_OFS, sizeof(serial[1]));

	new_n_sectors = ata_id_n_sectors(new_id);



	if (strcmp(model[0], model[1])) {

		printk(KERN_INFO

		       "ata%u: dev %u model number mismatch '%s' != '%s'\n",

		       ap->id, dev->devno, model[0], model[1]);

		return 0;

	}



	if (strcmp(serial[0], serial[1])) {

		printk(KERN_INFO

		       "ata%u: dev %u serial number mismatch '%s' != '%s'\n",

		       ap->id, dev->devno, serial[0], serial[1]);

		return 0;

	}



	if (dev->class == ATA_DEV_ATA && dev->n_sectors != new_n_sectors) {

		printk(KERN_INFO

		       "ata%u: dev %u n_sectors mismatch %llu != %llu\n",

		       ap->id, dev->devno, (unsigned long long)dev->n_sectors,

		       (unsigned long long)new_n_sectors);

		return 0;

	}



	return 1;

}



/**

 *	ata_dev_revalidate - Revalidate ATA device

 *	@ap: port on which the device to revalidate resides

 *	@dev: device to revalidate

 *	@post_reset: is this revalidation after reset?

 *

 *	Re-read IDENTIFY page and make sure @dev is still attached to

 *	the port.

 *

 *	LOCKING:

 *	Kernel thread context (may sleep)

 *

 *	RETURNS:

 *	0 on success, negative errno otherwise

 */

int ata_dev_revalidate(struct ata_port *ap, struct ata_device *dev,

		       int post_reset)

{

	unsigned int class;

	u16 *id;

	int rc;



	if (!ata_dev_present(dev))

		return -ENODEV;



	class = dev->class;

	id = NULL;



	/* allocate & read ID data */

	rc = ata_dev_read_id(ap, dev, &class, post_reset, &id);

	if (rc)

		goto fail;



	/* is the device still there? */

	if (!ata_dev_same_device(ap, dev, class, id)) {

		rc = -ENODEV;

		goto fail;

	}



	kfree(dev->id);

	dev->id = id;



	/* configure device according to the new ID */

	return ata_dev_configure(ap, dev, 0);



 fail:

	printk(KERN_ERR "ata%u: dev %u revalidation failed (errno=%d)\n",

	       ap->id, dev->devno, rc);

	kfree(id);

	return rc;

}



static void ata_pr_blacklisted(const struct ata_port *ap,

			       const struct ata_device *dev)

{
@@ -4964,6 +5078,7 @@ EXPORT_SYMBOL_GPL(sata_std_hardreset); 
EXPORT_SYMBOL_GPL(ata_std_postreset);

EXPORT_SYMBOL_GPL(ata_std_probe_reset);

EXPORT_SYMBOL_GPL(ata_drive_probe_reset);

EXPORT_SYMBOL_GPL(ata_dev_revalidate);

EXPORT_SYMBOL_GPL(ata_port_disable);

EXPORT_SYMBOL_GPL(ata_ratelimit);

EXPORT_SYMBOL_GPL(ata_busy_sleep);

include/linux/libata.h

+2 −0
Original line number Diff line number Diff line
@@ -485,6 +485,8 @@ extern int ata_std_softreset(struct ata_port *ap, int verbose, 
extern int sata_std_hardreset(struct ata_port *ap, int verbose,

			      unsigned int *class);

extern void ata_std_postreset(struct ata_port *ap, unsigned int *classes);

extern int ata_dev_revalidate(struct ata_port *ap, struct ata_device *dev,

			      int post_reset);

extern void ata_port_disable(struct ata_port *);

extern void ata_std_ports(struct ata_ioports *ioaddr);

#ifdef CONFIG_PCI