block: sed-opal: Add ioctl to return device status

Provide a mechanism to retrieve basic status information about
the device, including the "supported" flag indicating whether
SED-OPAL is supported. The information returned is from the various
feature descriptors received during the discovery0 step, and so
this ioctl does nothing more than perform the discovery0 step
and then save the information received. See "struct opal_status"
and OPAL_FL_* bits for the status information currently returned.

This is necessary to be able to check whether a device is OPAL
enabled, set up, locked or unlocked from userspace programs
like systemd-cryptsetup and libcryptsetup. Right now we just
have to assume the user 'knows' or blindly attempt setup/lock/unlock
operations.

Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Link: https://lore.kernel.org/r/20220816140713.84893-1-luca.boccassi@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/opal_proto.h b/block/opal_proto.h
index b486b3ec7dc41e95a203524400b06a1a5f5f610c..7152aa1f1a49e3bf177ce65f4e64990892deca57 100644 (file)
--- a/block/opal_proto.h
+++ b/block/opal_proto.h
@@ -39,7 +39,12 @@ enum opal_response_token {
 #define FIRST_TPER_SESSION_NUM 4096
 
 #define TPER_SYNC_SUPPORTED 0x01
+/* FC_LOCKING features */
+#define LOCKING_SUPPORTED_MASK 0x01
+#define LOCKING_ENABLED_MASK 0x02
+#define LOCKED_MASK 0x04
 #define MBR_ENABLED_MASK 0x10
+#define MBR_DONE_MASK 0x20
 
 #define TINY_ATOM_DATA_MASK 0x3F
 #define TINY_ATOM_SIGNED 0x40

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 9700197000f206eb1e9b88695a960beecfdb8ea7..2c5327a0543a66889e3b5eb0c0ec0786e1845c19 100644 (file)
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -74,8 +74,7 @@ struct parsed_resp {
 };
 
 struct opal_dev {
-       bool supported;
-       bool mbr_enabled;
+       u32 flags;
 
        void *data;
        sec_send_recv *send_recv;
@@ -280,6 +279,30 @@ static bool check_tper(const void *data)
        return true;
 }
 
+static bool check_lcksuppt(const void *data)
+{
+       const struct d0_locking_features *lfeat = data;
+       u8 sup_feat = lfeat->supported_features;
+
+       return !!(sup_feat & LOCKING_SUPPORTED_MASK);
+}
+
+static bool check_lckenabled(const void *data)
+{
+       const struct d0_locking_features *lfeat = data;
+       u8 sup_feat = lfeat->supported_features;
+
+       return !!(sup_feat & LOCKING_ENABLED_MASK);
+}
+
+static bool check_locked(const void *data)
+{
+       const struct d0_locking_features *lfeat = data;
+       u8 sup_feat = lfeat->supported_features;
+
+       return !!(sup_feat & LOCKED_MASK);
+}
+
 static bool check_mbrenabled(const void *data)
 {
        const struct d0_locking_features *lfeat = data;
@@ -288,6 +311,14 @@ static bool check_mbrenabled(const void *data)
        return !!(sup_feat & MBR_ENABLED_MASK);
 }
 
+static bool check_mbrdone(const void *data)
+{
+       const struct d0_locking_features *lfeat = data;
+       u8 sup_feat = lfeat->supported_features;
+
+       return !!(sup_feat & MBR_DONE_MASK);
+}
+
 static bool check_sum(const void *data)
 {
        const struct d0_single_user_mode *sum = data;
@@ -435,7 +466,7 @@ static int opal_discovery0_end(struct opal_dev *dev)
        u32 hlen = be32_to_cpu(hdr->length);
 
        print_buffer(dev->resp, hlen);
-       dev->mbr_enabled = false;
+       dev->flags &= OPAL_FL_SUPPORTED;
 
        if (hlen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
                pr_debug("Discovery length overflows buffer (%zu+%u)/%u\n",
@@ -461,7 +492,16 @@ static int opal_discovery0_end(struct opal_dev *dev)
                        check_geometry(dev, body);
                        break;
                case FC_LOCKING:
-                       dev->mbr_enabled = check_mbrenabled(body->features);
+                       if (check_lcksuppt(body->features))
+                               dev->flags |= OPAL_FL_LOCKING_SUPPORTED;
+                       if (check_lckenabled(body->features))
+                               dev->flags |= OPAL_FL_LOCKING_ENABLED;
+                       if (check_locked(body->features))
+                               dev->flags |= OPAL_FL_LOCKED;
+                       if (check_mbrenabled(body->features))
+                               dev->flags |= OPAL_FL_MBR_ENABLED;
+                       if (check_mbrdone(body->features))
+                               dev->flags |= OPAL_FL_MBR_DONE;
                        break;
                case FC_ENTERPRISE:
                case FC_DATASTORE:
@@ -2109,7 +2149,8 @@ static int check_opal_support(struct opal_dev *dev)
        mutex_lock(&dev->dev_lock);
        setup_opal_dev(dev);
        ret = opal_discovery0_step(dev);
-       dev->supported = !ret;
+       if (!ret)
+               dev->flags |= OPAL_FL_SUPPORTED;
        mutex_unlock(&dev->dev_lock);
 
        return ret;
@@ -2148,6 +2189,7 @@ struct opal_dev *init_opal_dev(void *data, sec_send_recv *send_recv)
 
        INIT_LIST_HEAD(&dev->unlk_lst);
        mutex_init(&dev->dev_lock);
+       dev->flags = 0;
        dev->data = data;
        dev->send_recv = send_recv;
        if (check_opal_support(dev) != 0) {
@@ -2528,7 +2570,7 @@ bool opal_unlock_from_suspend(struct opal_dev *dev)
        if (!dev)
                return false;
 
-       if (!dev->supported)
+       if (!(dev->flags & OPAL_FL_SUPPORTED))
                return false;
 
        mutex_lock(&dev->dev_lock);
@@ -2546,7 +2588,7 @@ bool opal_unlock_from_suspend(struct opal_dev *dev)
                        was_failure = true;
                }
 
-               if (dev->mbr_enabled) {
+               if (dev->flags & OPAL_FL_MBR_ENABLED) {
                        ret = __opal_set_mbr_done(dev, &suspend->unlk.session.opal_key);
                        if (ret)
                                pr_debug("Failed to set MBR Done in S3 resume\n");
@@ -2620,6 +2662,23 @@ static int opal_generic_read_write_table(struct opal_dev *dev,
        return ret;
 }
 
+static int opal_get_status(struct opal_dev *dev, void __user *data)
+{
+       struct opal_status sts = {0};
+
+       /*
+        * check_opal_support() error is not fatal,
+        * !dev->supported is a valid condition
+        */
+       if (!check_opal_support(dev))
+               sts.flags = dev->flags;
+       if (copy_to_user(data, &sts, sizeof(sts))) {
+               pr_debug("Error copying status to userspace\n");
+               return -EFAULT;
+       }
+       return 0;
+}
+
 int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
 {
        void *p;
@@ -2629,12 +2688,14 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
                return -EACCES;
        if (!dev)
                return -ENOTSUPP;
-       if (!dev->supported)
+       if (!(dev->flags & OPAL_FL_SUPPORTED))
                return -ENOTSUPP;
 
-       p = memdup_user(arg, _IOC_SIZE(cmd));
-       if (IS_ERR(p))
-               return PTR_ERR(p);
+       if (cmd & IOC_IN) {
+               p = memdup_user(arg, _IOC_SIZE(cmd));
+               if (IS_ERR(p))
+                       return PTR_ERR(p);
+       }
 
        switch (cmd) {
        case IOC_OPAL_SAVE:
@@ -2685,11 +2746,15 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
        case IOC_OPAL_GENERIC_TABLE_RW:
                ret = opal_generic_read_write_table(dev, p);
                break;
+       case IOC_OPAL_GET_STATUS:
+               ret = opal_get_status(dev, arg);
+               break;
        default:
                break;
        }
 
-       kfree(p);
+       if (cmd & IOC_IN)
+               kfree(p);
        return ret;
 }
 EXPORT_SYMBOL_GPL(sed_ioctl);

diff --git a/include/linux/sed-opal.h b/include/linux/sed-opal.h
index 1ac0d712a9c36f440f4f3db92783cc16e55a7370..6f837bb6c7156aede902c37e84a5016c1376e681 100644 (file)
--- a/include/linux/sed-opal.h
+++ b/include/linux/sed-opal.h
@@ -43,6 +43,7 @@ static inline bool is_sed_ioctl(unsigned int cmd)
        case IOC_OPAL_MBR_DONE:
        case IOC_OPAL_WRITE_SHADOW_MBR:
        case IOC_OPAL_GENERIC_TABLE_RW:
+       case IOC_OPAL_GET_STATUS:
                return true;
        }
        return false;

diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h
index 6f5af1a84213bb72ac262b9138b087076dd5c5a8..2573772e2fb3e946dcc122da9a75f52b3b2b2fb9 100644 (file)
--- a/include/uapi/linux/sed-opal.h
+++ b/include/uapi/linux/sed-opal.h
@@ -132,6 +132,18 @@ struct opal_read_write_table {
        __u64 priv;
 };
 
+#define OPAL_FL_SUPPORTED              0x00000001
+#define OPAL_FL_LOCKING_SUPPORTED      0x00000002
+#define OPAL_FL_LOCKING_ENABLED                0x00000004
+#define OPAL_FL_LOCKED                 0x00000008
+#define OPAL_FL_MBR_ENABLED            0x00000010
+#define OPAL_FL_MBR_DONE               0x00000020
+
+struct opal_status {
+       __u32 flags;
+       __u32 reserved;
+};
+
 #define IOC_OPAL_SAVE              _IOW('p', 220, struct opal_lock_unlock)
 #define IOC_OPAL_LOCK_UNLOCK       _IOW('p', 221, struct opal_lock_unlock)
 #define IOC_OPAL_TAKE_OWNERSHIP            _IOW('p', 222, struct opal_key)
@@ -148,5 +160,6 @@ struct opal_read_write_table {
 #define IOC_OPAL_MBR_DONE           _IOW('p', 233, struct opal_mbr_done)
 #define IOC_OPAL_WRITE_SHADOW_MBR   _IOW('p', 234, struct opal_shadow_mbr)
 #define IOC_OPAL_GENERIC_TABLE_RW   _IOW('p', 235, struct opal_read_write_table)
+#define IOC_OPAL_GET_STATUS         _IOR('p', 236, struct opal_status)
 
 #endif /* _UAPI_SED_OPAL_H */