s390/dasd: add query host access to volume support
With this feature, applications can query if a DASD volume is online
to another operating system instances by checking the online status of
all attached hosts from the storage server.
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index c78db05..4adb6d1 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -75,6 +75,8 @@
static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
static void dasd_profile_init(struct dasd_profile *, struct dentry *);
static void dasd_profile_exit(struct dasd_profile *);
+static void dasd_hosts_init(struct dentry *, struct dasd_device *);
+static void dasd_hosts_exit(struct dasd_device *);
/*
* SECTION: Operations on the device structure.
@@ -267,6 +269,7 @@
dasd_debugfs_setup(dev_name(&device->cdev->dev),
dasd_debugfs_root_entry);
dasd_profile_init(&device->profile, device->debugfs_dentry);
+ dasd_hosts_init(device->debugfs_dentry, device);
/* register 'device' debug area, used for all DBF_DEV_XXX calls */
device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
@@ -304,6 +307,7 @@
return rc;
dasd_device_clear_timer(device);
dasd_profile_exit(&device->profile);
+ dasd_hosts_exit(device);
debugfs_remove(device->debugfs_dentry);
DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
if (device->debug_area != NULL) {
@@ -1150,6 +1154,58 @@
#endif /* CONFIG_DASD_PROFILE */
+static int dasd_hosts_show(struct seq_file *m, void *v)
+{
+ struct dasd_device *device;
+ int rc = -EOPNOTSUPP;
+
+ device = m->private;
+ dasd_get_device(device);
+
+ if (device->discipline->hosts_print)
+ rc = device->discipline->hosts_print(device, m);
+
+ dasd_put_device(device);
+ return rc;
+}
+
+static int dasd_hosts_open(struct inode *inode, struct file *file)
+{
+ struct dasd_device *device = inode->i_private;
+
+ return single_open(file, dasd_hosts_show, device);
+}
+
+static const struct file_operations dasd_hosts_fops = {
+ .owner = THIS_MODULE,
+ .open = dasd_hosts_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void dasd_hosts_exit(struct dasd_device *device)
+{
+ debugfs_remove(device->hosts_dentry);
+ device->hosts_dentry = NULL;
+}
+
+static void dasd_hosts_init(struct dentry *base_dentry,
+ struct dasd_device *device)
+{
+ struct dentry *pde;
+ umode_t mode;
+
+ if (!base_dentry)
+ return;
+
+ mode = S_IRUSR | S_IFREG;
+ pde = debugfs_create_file("host_access_list", mode, base_dentry,
+ device, &dasd_hosts_fops);
+ if (pde && !IS_ERR(pde))
+ device->hosts_dentry = pde;
+}
+
/*
* Allocate memory for a channel program with 'cplength' channel
* command words and 'datasize' additional space. There are two
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 2f18f61..3cdbce4 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -982,6 +982,32 @@
static DEVICE_ATTR(safe_offline, 0200, NULL, dasd_safe_offline_store);
static ssize_t
+dasd_access_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct ccw_device *cdev = to_ccwdev(dev);
+ struct dasd_device *device;
+ int count;
+
+ device = dasd_device_from_cdev(cdev);
+ if (IS_ERR(device))
+ return PTR_ERR(device);
+
+ if (device->discipline->host_access_count)
+ count = device->discipline->host_access_count(device);
+ else
+ count = -EOPNOTSUPP;
+
+ dasd_put_device(device);
+ if (count < 0)
+ return count;
+
+ return sprintf(buf, "%d\n", count);
+}
+
+static DEVICE_ATTR(host_access_count, 0444, dasd_access_show, NULL);
+
+static ssize_t
dasd_discipline_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -1471,6 +1497,7 @@
&dev_attr_reservation_policy.attr,
&dev_attr_last_known_reservation_state.attr,
&dev_attr_safe_offline.attr,
+ &dev_attr_host_access_count.attr,
&dev_attr_path_masks.attr,
NULL,
};
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index c1b4ae5..3b70d37 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -19,6 +19,7 @@
#include <linux/module.h>
#include <linux/compat.h>
#include <linux/init.h>
+#include <linux/seq_file.h>
#include <asm/css_chars.h>
#include <asm/debug.h>
@@ -4627,6 +4628,167 @@
return rc;
}
+static int dasd_eckd_query_host_access(struct dasd_device *device,
+ struct dasd_psf_query_host_access *data)
+{
+ struct dasd_eckd_private *private = device->private;
+ struct dasd_psf_query_host_access *host_access;
+ struct dasd_psf_prssd_data *prssdp;
+ struct dasd_ccw_req *cqr;
+ struct ccw1 *ccw;
+ int rc;
+
+ /* not available for HYPER PAV alias devices */
+ if (!device->block && private->lcu->pav == HYPER_PAV)
+ return -EOPNOTSUPP;
+
+ cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */,
+ sizeof(struct dasd_psf_prssd_data) + 1,
+ device);
+ if (IS_ERR(cqr)) {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+ "Could not allocate read message buffer request");
+ return PTR_ERR(cqr);
+ }
+ host_access = kzalloc(sizeof(*host_access), GFP_KERNEL | GFP_DMA);
+ if (!host_access) {
+ dasd_sfree_request(cqr, device);
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+ "Could not allocate host_access buffer");
+ return -ENOMEM;
+ }
+ cqr->startdev = device;
+ cqr->memdev = device;
+ cqr->block = NULL;
+ cqr->retries = 256;
+ cqr->expires = 10 * HZ;
+
+ /* Prepare for Read Subsystem Data */
+ prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+ memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
+ prssdp->order = PSF_ORDER_PRSSD;
+ prssdp->suborder = PSF_SUBORDER_QHA; /* query host access */
+ /* LSS and Volume that will be queried */
+ prssdp->lss = private->ned->ID;
+ prssdp->volume = private->ned->unit_addr;
+ /* all other bytes of prssdp must be zero */
+
+ ccw = cqr->cpaddr;
+ ccw->cmd_code = DASD_ECKD_CCW_PSF;
+ ccw->count = sizeof(struct dasd_psf_prssd_data);
+ ccw->flags |= CCW_FLAG_CC;
+ ccw->flags |= CCW_FLAG_SLI;
+ ccw->cda = (__u32)(addr_t) prssdp;
+
+ /* Read Subsystem Data - query host access */
+ ccw++;
+ ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+ ccw->count = sizeof(struct dasd_psf_query_host_access);
+ ccw->flags |= CCW_FLAG_SLI;
+ ccw->cda = (__u32)(addr_t) host_access;
+
+ cqr->buildclk = get_tod_clock();
+ cqr->status = DASD_CQR_FILLED;
+ rc = dasd_sleep_on(cqr);
+ if (rc == 0) {
+ *data = *host_access;
+ } else {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+ "Reading host access data failed with rc=%d\n",
+ rc);
+ rc = -EOPNOTSUPP;
+ }
+
+ dasd_sfree_request(cqr, cqr->memdev);
+ kfree(host_access);
+ return rc;
+}
+/*
+ * return number of grouped devices
+ */
+static int dasd_eckd_host_access_count(struct dasd_device *device)
+{
+ struct dasd_psf_query_host_access *access;
+ struct dasd_ckd_path_group_entry *entry;
+ struct dasd_ckd_host_information *info;
+ int count = 0;
+ int rc, i;
+
+ access = kzalloc(sizeof(*access), GFP_NOIO);
+ if (!access) {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+ "Could not allocate access buffer");
+ return -ENOMEM;
+ }
+ rc = dasd_eckd_query_host_access(device, access);
+ if (rc) {
+ kfree(access);
+ return rc;
+ }
+
+ info = (struct dasd_ckd_host_information *)
+ access->host_access_information;
+ for (i = 0; i < info->entry_count; i++) {
+ entry = (struct dasd_ckd_path_group_entry *)
+ (info->entry + i * info->entry_size);
+ if (entry->status_flags & DASD_ECKD_PG_GROUPED)
+ count++;
+ }
+
+ kfree(access);
+ return count;
+}
+
+/*
+ * write host access information to a sequential file
+ */
+static int dasd_hosts_print(struct dasd_device *device, struct seq_file *m)
+{
+ struct dasd_psf_query_host_access *access;
+ struct dasd_ckd_path_group_entry *entry;
+ struct dasd_ckd_host_information *info;
+ char sysplex[9] = "";
+ int rc, i, j;
+
+ access = kzalloc(sizeof(*access), GFP_NOIO);
+ if (!access) {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+ "Could not allocate access buffer");
+ return -ENOMEM;
+ }
+ rc = dasd_eckd_query_host_access(device, access);
+ if (rc) {
+ kfree(access);
+ return rc;
+ }
+
+ info = (struct dasd_ckd_host_information *)
+ access->host_access_information;
+ for (i = 0; i < info->entry_count; i++) {
+ entry = (struct dasd_ckd_path_group_entry *)
+ (info->entry + i * info->entry_size);
+ /* PGID */
+ seq_puts(m, "pgid ");
+ for (j = 0; j < 11; j++)
+ seq_printf(m, "%02x", entry->pgid[j]);
+ seq_putc(m, '\n');
+ /* FLAGS */
+ seq_printf(m, "status_flags %02x\n", entry->status_flags);
+ /* SYSPLEX NAME */
+ memcpy(&sysplex, &entry->sysplex_name, sizeof(sysplex) - 1);
+ EBCASC(sysplex, sizeof(sysplex));
+ seq_printf(m, "sysplex_name %8s\n", sysplex);
+ /* SUPPORTED CYLINDER */
+ seq_printf(m, "supported_cylinder %d\n", entry->cylinder);
+ /* TIMESTAMP */
+ seq_printf(m, "timestamp %lu\n", (unsigned long)
+ entry->timestamp);
+ }
+ kfree(access);
+
+ return 0;
+}
+
/*
* Perform Subsystem Function - CUIR response
*/
@@ -5099,6 +5261,8 @@
.get_uid = dasd_eckd_get_uid,
.kick_validate = dasd_eckd_kick_validate_server,
.check_attention = dasd_eckd_check_attention,
+ .host_access_count = dasd_eckd_host_access_count,
+ .hosts_print = dasd_hosts_print,
};
static int __init
diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h
index 6d9a6d3..862ee42 100644
--- a/drivers/s390/block/dasd_eckd.h
+++ b/drivers/s390/block/dasd_eckd.h
@@ -53,6 +53,7 @@
*/
#define PSF_ORDER_PRSSD 0x18
#define PSF_ORDER_CUIR_RESPONSE 0x1A
+#define PSF_SUBORDER_QHA 0x1C
#define PSF_ORDER_SSC 0x1D
/*
@@ -81,6 +82,8 @@
#define ATTENTION_LENGTH_CUIR 0x0e
#define ATTENTION_FORMAT_CUIR 0x01
+#define DASD_ECKD_PG_GROUPED 0x10
+
/*
* Size that is reportet for large volumes in the old 16-bit no_cyl field
*/
@@ -403,13 +406,41 @@
__u8 ssid;
} __packed;
+struct dasd_ckd_path_group_entry {
+ __u8 status_flags;
+ __u8 pgid[11];
+ __u8 sysplex_name[8];
+ __u32 timestamp;
+ __u32 cylinder;
+ __u8 reserved[4];
+} __packed;
+
+struct dasd_ckd_host_information {
+ __u8 access_flags;
+ __u8 entry_size;
+ __u16 entry_count;
+ __u8 entry[16390];
+} __packed;
+
+struct dasd_psf_query_host_access {
+ __u8 access_flag;
+ __u8 version;
+ __u16 CKD_length;
+ __u16 SCSI_length;
+ __u8 unused[10];
+ __u8 host_access_information[16394];
+} __packed;
+
/*
* Perform Subsystem Function - Prepare for Read Subsystem Data
*/
struct dasd_psf_prssd_data {
unsigned char order;
unsigned char flags;
- unsigned char reserved[4];
+ unsigned char reserved1;
+ unsigned char reserved2;
+ unsigned char lss;
+ unsigned char volume;
unsigned char suborder;
unsigned char varies[5];
} __attribute__ ((packed));
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 0f0add9..6132733 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -365,6 +365,8 @@
int (*get_uid) (struct dasd_device *, struct dasd_uid *);
void (*kick_validate) (struct dasd_device *);
int (*check_attention)(struct dasd_device *, __u8);
+ int (*host_access_count)(struct dasd_device *);
+ int (*hosts_print)(struct dasd_device *, struct seq_file *);
};
extern struct dasd_discipline *dasd_diag_discipline_pointer;
@@ -487,6 +489,7 @@
unsigned long blk_timeout;
struct dentry *debugfs_dentry;
+ struct dentry *hosts_dentry;
struct dasd_profile profile;
};
