Commit 2cdd6410 authored by Boaz Harrosh's avatar Boaz Harrosh Committed by James Bottomley
Browse files

[SCSI] libosd: osd_dev_info: Unique Identification of an OSD device 



Define an osd_dev_info structure that Uniquely identifies an OSD
device lun on the network. The identification is built from unique
target attributes and is the same for all network/SAN machines.

osduld_info_lookup() - NEW
    New API that will lookup an osd_dev by its osd_dev_info.
    This is used by pNFS-objects for cross network global device
    identification. And by exofs multy-device support, the device
    info is specified in the on-disk exofs device table.

osduld_device_info() - NEW
    Given an osd_dev handle returns its associated osd_dev_info.
    The ULD fetches this information at startup and hangs it on
    each OSD device. (This is a fast operation that can be called
    at any condition)

osduld_device_same() - NEW
    With a given osd_dev at one hand and an osd_dev_info
    at another, we would like to know if they are the same
    device.
    Two osd_dev handles can be checked by:
        osduld_device_same(od1, osduld_device_info(od2));

osd_auto_detect_ver() - REVISED
    Now returns an osd_dev_info structure. Is only called once
    by ULD as before. See added comments for how to use.

Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@suse.de>
parent d6ae4333

drivers/scsi/osd/osd_initiator.c

+20 −6
Original line number Diff line number Diff line
@@ -73,7 +73,8 @@ static const char *_osd_ver_desc(struct osd_request *or) 


#define ATTR_DEF_RI(id, len) ATTR_DEF(OSD_APAGE_ROOT_INFORMATION, id, len)



static int _osd_print_system_info(struct osd_dev *od, void *caps)

static int _osd_get_print_system_info(struct osd_dev *od,

	void *caps, struct osd_dev_info *odi)

{

	struct osd_request *or;

	struct osd_attr get_attrs[] = {
@@ -137,8 +138,12 @@ static int _osd_print_system_info(struct osd_dev *od, void *caps) 
	OSD_INFO("PRODUCT_SERIAL_NUMBER  [%s]\n",

		(char *)pFirst);



	pFirst = get_attrs[a].val_ptr;

	OSD_INFO("OSD_NAME               [%s]\n", (char *)pFirst);

	odi->osdname_len = get_attrs[a].len;

	/* Avoid NULL for memcmp optimization 0-length is good enough */

	odi->osdname = kzalloc(odi->osdname_len + 1, GFP_KERNEL);

	if (odi->osdname_len)

		memcpy(odi->osdname, get_attrs[a].val_ptr, odi->osdname_len);

	OSD_INFO("OSD_NAME               [%s]\n", odi->osdname);

	a++;



	pFirst = get_attrs[a++].val_ptr;
@@ -171,6 +176,14 @@ static int _osd_print_system_info(struct osd_dev *od, void *caps) 
				   sid_dump, sizeof(sid_dump), true);

		OSD_INFO("OSD_SYSTEM_ID(%d)\n"

			 "        [%s]\n", len, sid_dump);



		if (unlikely(len > sizeof(odi->systemid))) {

			OSD_ERR("OSD Target error: OSD_SYSTEM_ID too long(%d). "

				"device idetification might not work\n", len);

			len = sizeof(odi->systemid);

		}

		odi->systemid_len = len;

		memcpy(odi->systemid, get_attrs[a].val_ptr, len);

		a++;

	}

out:
@@ -178,16 +191,17 @@ out: 
	return ret;

}



int osd_auto_detect_ver(struct osd_dev *od, void *caps)

int osd_auto_detect_ver(struct osd_dev *od,

	void *caps, struct osd_dev_info *odi)

{

	int ret;



	/* Auto-detect the osd version */

	ret = _osd_print_system_info(od, caps);

	ret = _osd_get_print_system_info(od, caps, odi);

	if (ret) {

		osd_dev_set_ver(od, OSD_VER1);

		OSD_DEBUG("converting to OSD1\n");

		ret = _osd_print_system_info(od, caps);

		ret = _osd_get_print_system_info(od, caps, odi);

	}



	return ret;

drivers/scsi/osd/osd_uld.c

+97 −3
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ struct osd_uld_device { 
	struct device class_dev;

	struct cdev cdev;

	struct osd_dev od;

	struct osd_dev_info odi;

	struct gendisk *disk;

};
@@ -225,6 +226,72 @@ free_od: 
}

EXPORT_SYMBOL(osduld_path_lookup);



static inline bool _the_same_or_null(const u8 *a1, unsigned a1_len,

				     const u8 *a2, unsigned a2_len)

{

	if (!a2_len) /* User string is Empty means don't care */

		return true;



	if (a1_len != a2_len)

		return false;



	return 0 == memcmp(a1, a2, a1_len);

}



struct find_oud_t {

	const struct osd_dev_info *odi;

	struct device *dev;

	struct osd_uld_device *oud;

} ;



int _mach_odi(struct device *dev, void *find_data)

{

	struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,

						  class_dev);

	struct find_oud_t *fot = find_data;

	const struct osd_dev_info *odi = fot->odi;



	if (_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,

			      odi->systemid, odi->systemid_len) &&

	    _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,

			      odi->osdname, odi->osdname_len)) {

		OSD_DEBUG("found device sysid_len=%d osdname=%d\n",

			  odi->systemid_len, odi->osdname_len);

		fot->oud = oud;

		return 1;

	} else {

		return 0;

	}

}



/* osduld_info_lookup - Loop through all devices, return the requested osd_dev.

 *

 * if @odi->systemid_len and/or @odi->osdname_len are zero, they act as a don't

 * care. .e.g if they're both zero /dev/osd0 is returned.

 */

struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi)

{

	struct find_oud_t find = {.odi = odi};



	find.dev = class_find_device(&osd_uld_class, NULL, &find, _mach_odi);

	if (likely(find.dev)) {

		struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);



		if (unlikely(!odh)) {

			put_device(find.dev);

			return ERR_PTR(-ENOMEM);

		}



		odh->od = find.oud->od;

		odh->oud = find.oud;



		return &odh->od;

	}



	return ERR_PTR(-ENODEV);

}

EXPORT_SYMBOL(osduld_info_lookup);



void osduld_put_device(struct osd_dev *od)

{

	if (od && !IS_ERR(od)) {
@@ -240,14 +307,39 @@ void osduld_put_device(struct osd_dev *od) 
		 * is called after the fops->release. A get_/put_ pair makes

		 * sure we have a cdev for the duration of fput

		 */

		if (odh->file) {

			get_device(&oud->class_dev);

			fput(odh->file);

		}

		put_device(&oud->class_dev);

		kfree(odh);

	}

}

EXPORT_SYMBOL(osduld_put_device);



const struct osd_dev_info *osduld_device_info(struct osd_dev *od)

{

	struct osd_dev_handle *odh =

				container_of(od, struct osd_dev_handle, od);

	return &odh->oud->odi;

}

EXPORT_SYMBOL(osduld_device_info);



bool osduld_device_same(struct osd_dev *od, const struct osd_dev_info *odi)

{

	struct osd_dev_handle *odh =

				container_of(od, struct osd_dev_handle, od);

	struct osd_uld_device *oud = odh->oud;



	return (oud->odi.systemid_len == odi->systemid_len) &&

		_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,

				 odi->systemid, odi->systemid_len) &&

		(oud->odi.osdname_len == odi->osdname_len) &&

		_the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,

				  odi->osdname, odi->osdname_len);

}

EXPORT_SYMBOL(osduld_device_same);



/*

 * Scsi Device operations

 */
@@ -268,7 +360,7 @@ static int __detect_osd(struct osd_uld_device *oud) 
		OSD_ERR("warning: scsi_test_unit_ready failed\n");



	osd_sec_init_nosec_doall_caps(caps, &osd_root_object, false, true);

	if (osd_auto_detect_ver(&oud->od, caps))

	if (osd_auto_detect_ver(&oud->od, caps, &oud->odi))

		return -ENODEV;



	return 0;
@@ -280,6 +372,8 @@ static void __remove(struct device *dev) 
						  class_dev);

	struct scsi_device *scsi_device = oud->od.scsi_device;



	kfree(oud->odi.osdname);



	if (oud->cdev.owner)

		cdev_del(&oud->cdev);

include/scsi/osd_initiator.h

+34 −4
Original line number Diff line number Diff line
@@ -55,10 +55,24 @@ struct osd_dev { 
#endif

};



/* Retrieve/return osd_dev(s) for use by Kernel clients */

struct osd_dev *osduld_path_lookup(const char *dev_name); /*Use IS_ERR/ERR_PTR*/

/* Unique Identification of an OSD device */

struct osd_dev_info {

	unsigned systemid_len;

	u8 systemid[OSD_SYSTEMID_LEN];

	unsigned osdname_len;

	u8 *osdname;

};



/* Retrieve/return osd_dev(s) for use by Kernel clients

 * Use IS_ERR/ERR_PTR on returned "osd_dev *".

 */

struct osd_dev *osduld_path_lookup(const char *dev_name);

struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi);

void osduld_put_device(struct osd_dev *od);



const struct osd_dev_info *osduld_device_info(struct osd_dev *od);

bool osduld_device_same(struct osd_dev *od, const struct osd_dev_info *odi);



/* Add/remove test ioctls from external modules */

typedef int (do_test_fn)(struct osd_dev *od, unsigned cmd, unsigned long arg);

int osduld_register_test(unsigned ioctl, do_test_fn *do_test);
@@ -68,8 +82,24 @@ void osduld_unregister_test(unsigned ioctl); 
void osd_dev_init(struct osd_dev *od, struct scsi_device *scsi_device);

void osd_dev_fini(struct osd_dev *od);



/* some hi level device operations */

int osd_auto_detect_ver(struct osd_dev *od, void *caps);    /* GFP_KERNEL */

/**

 * osd_auto_detect_ver - Detect the OSD version, return Unique Identification

 *

 * @od:     OSD target lun handle

 * @caps:   Capabilities authorizing OSD root read attributes access

 * @odi:    Retrieved information uniquely identifying the osd target lun

 *          Note: odi->osdname must be kfreed by caller.

 *

 * Auto detects the OSD version of the OSD target and sets the @od

 * accordingly. Meanwhile also returns the "system id" and "osd name" root

 * attributes which uniquely identify the OSD target. This member is usually

 * called by the ULD. ULD users should call osduld_device_info().

 * This rutine allocates osd requests and memory at GFP_KERNEL level and might

 * sleep.

 */

int osd_auto_detect_ver(struct osd_dev *od,

	void *caps, struct osd_dev_info *odi);



static inline struct request_queue *osd_request_queue(struct osd_dev *od)

{

	return od->scsi_device->request_queue;

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