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

[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
    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 <>
Signed-off-by: default avatarJames Bottomley <>
parent d6ae4333
......@@ -73,7 +73,8 @@ static const char *_osd_ver_desc(struct osd_request *or)
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)
(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);
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);
" [%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);
......@@ -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;
......@@ -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:
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,
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}; = class_find_device(&osd_uld_class, NULL, &find, _mach_odi);
if (likely( {
struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);
if (unlikely(!odh)) {
return ERR_PTR(-ENOMEM);
odh->od = find.oud->od;
odh->oud = find.oud;
return &odh->od;
return ERR_PTR(-ENODEV);
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) {
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;
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);
* 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)
struct scsi_device *scsi_device = oud->od.scsi_device;
if (oud->cdev.owner)
......@@ -55,10 +55,24 @@ struct osd_dev {
/* 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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