From 2cdd6410e5a1665823f2a048fc7f8f6a8384be1d Mon Sep 17 00:00:00 2001 From: Boaz Harrosh Date: Sun, 29 Nov 2009 16:26:45 +0200 Subject: [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: Boaz Harrosh Signed-off-by: James Bottomley --- include/scsi/osd_initiator.h | 38 ++++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-) (limited to 'include/scsi') diff --git a/include/scsi/osd_initiator.h b/include/scsi/osd_initiator.h index 589e5f0d67b..3ec346e15dd 100644 --- a/include/scsi/osd_initiator.h +++ b/include/scsi/osd_initiator.h @@ -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; -- cgit v1.2.3