block: sed-opal: pass steps via argument rather than via opal_dev

The steps argument is only read by the next function, so it can
be passed directly as an argument rather than via opal_dev.

Normally, the steps is an array on the stack, so the pointer stops
being valid then the function that set opal_dev.steps returns.
If opal_dev.steps was not set to NULL before return it would become
a dangling pointer. When the steps are passed as argument this
becomes easier to see and more difficult to misuse.

Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/sed-opal.c b/block/sed-opal.c
index be0d633783c8d051c662c2d0a7f34a9f0c6f9903..f027c0cb682e6c99d11658eefb4bb43a3d505dee 100644 (file)
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -85,7 +85,6 @@ struct opal_dev {
        void *data;
        sec_send_recv *send_recv;
 
-       const struct opal_step *steps;
        struct mutex dev_lock;
        u16 comid;
        u32 hsn;
@@ -382,37 +381,34 @@ static void check_geometry(struct opal_dev *dev, const void *data)
        dev->lowest_lba = geo->lowest_aligned_lba;
 }
 
-static int next(struct opal_dev *dev)
+static int next(struct opal_dev *dev, const struct opal_step *steps,
+               size_t n_steps)
 {
        const struct opal_step *step;
-       int state = 0, error = 0;
+       size_t state;
+       int error = 0;
 
-       do {
-               step = &dev->steps[state];
-               if (!step->fn)
-                       break;
+       for (state = 0; state < n_steps; state++) {
+               step = &steps[state];
 
                error = step->fn(dev, step->data);
-               if (error) {
-                       pr_debug("Step %d (%pS) failed with error %d: %s\n",
-                                state, step->fn, error,
-                                opal_error_to_human(error));
-
-                       /* For each OPAL command we do a discovery0 then we
-                        * start some sort of session.
-                        * If we haven't passed state 1 then there was an error
-                        * on discovery0 or during the attempt to start a
-                        * session. Therefore we shouldn't attempt to terminate
-                        * a session, as one has not yet been created.
-                        */
-                       if (state > 1) {
-                               end_opal_session_error(dev);
-                               return error;
-                       }
+               if (error)
+                       goto out_error;
+       }
 
-               }
-               state++;
-       } while (!error);
+       return 0;
+
+out_error:
+       /*
+        * For each OPAL command the first step in steps does a discovery0
+        * and the second step starts some sort of session. If an error occurred
+        * in the first two steps (and thus stopping the loop with state <= 1)
+        * then there was an error before or during the attempt to start a
+        * session. Therefore we shouldn't attempt to terminate a session, as
+        * one has not yet been created.
+        */
+       if (state > 1)
+               end_opal_session_error(dev);
 
        return error;
 }
@@ -1836,17 +1832,13 @@ static int end_opal_session(struct opal_dev *dev, void *data)
 static int end_opal_session_error(struct opal_dev *dev)
 {
        const struct opal_step error_end_session[] = {
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
-       dev->steps = error_end_session;
-       return next(dev);
+       return next(dev, error_end_session, ARRAY_SIZE(error_end_session));
 }
 
-static inline void setup_opal_dev(struct opal_dev *dev,
-                                 const struct opal_step *steps)
+static inline void setup_opal_dev(struct opal_dev *dev)
 {
-       dev->steps = steps;
        dev->tsn = 0;
        dev->hsn = 0;
        dev->prev_data = NULL;
@@ -1855,14 +1847,13 @@ static inline void setup_opal_dev(struct opal_dev *dev,
 static int check_opal_support(struct opal_dev *dev)
 {
        const struct opal_step steps[] = {
-               { opal_discovery0, },
-               { NULL, }
+               { opal_discovery0, }
        };
        int ret;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, steps, ARRAY_SIZE(steps));
        dev->supported = !ret;
        mutex_unlock(&dev->dev_lock);
        return ret;
@@ -1919,14 +1910,13 @@ static int opal_secure_erase_locking_range(struct opal_dev *dev,
                { start_auth_opal_session, opal_session },
                { get_active_key, &opal_session->opal_key.lr },
                { gen_key, },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        int ret;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, erase_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, erase_steps, ARRAY_SIZE(erase_steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -1938,14 +1928,13 @@ static int opal_erase_locking_range(struct opal_dev *dev,
                { opal_discovery0, },
                { start_auth_opal_session, opal_session },
                { erase_locking_range, opal_session },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        int ret;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, erase_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, erase_steps, ARRAY_SIZE(erase_steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -1963,8 +1952,7 @@ static int opal_enable_disable_shadow_mbr(struct opal_dev *dev,
                { end_opal_session, },
                { start_admin1LSP_opal_session, &opal_mbr->key },
                { set_mbr_enable_disable, &enable_disable },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        int ret;
 
@@ -1973,8 +1961,8 @@ static int opal_enable_disable_shadow_mbr(struct opal_dev *dev,
                return -EINVAL;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, mbr_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, mbr_steps, ARRAY_SIZE(mbr_steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -1991,7 +1979,7 @@ static int opal_save(struct opal_dev *dev, struct opal_lock_unlock *lk_unlk)
        suspend->lr = lk_unlk->session.opal_key.lr;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, NULL);
+       setup_opal_dev(dev);
        add_suspend_info(dev, suspend);
        mutex_unlock(&dev->dev_lock);
        return 0;
@@ -2004,8 +1992,7 @@ static int opal_add_user_to_lr(struct opal_dev *dev,
                { opal_discovery0, },
                { start_admin1LSP_opal_session, &lk_unlk->session.opal_key },
                { add_user_to_lr, lk_unlk },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        int ret;
 
@@ -2027,8 +2014,8 @@ static int opal_add_user_to_lr(struct opal_dev *dev,
        }
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, steps, ARRAY_SIZE(steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -2038,14 +2025,13 @@ static int opal_reverttper(struct opal_dev *dev, struct opal_key *opal)
        const struct opal_step revert_steps[] = {
                { opal_discovery0, },
                { start_SIDASP_opal_session, opal },
-               { revert_tper, }, /* controller will terminate session */
-               { NULL, }
+               { revert_tper, } /* controller will terminate session */
        };
        int ret;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, revert_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, revert_steps, ARRAY_SIZE(revert_steps));
        mutex_unlock(&dev->dev_lock);
 
        /*
@@ -2065,19 +2051,20 @@ static int __opal_lock_unlock(struct opal_dev *dev,
                { opal_discovery0, },
                { start_auth_opal_session, &lk_unlk->session },
                { lock_unlock_locking_range, lk_unlk },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        const struct opal_step unlock_sum_steps[] = {
                { opal_discovery0, },
                { start_auth_opal_session, &lk_unlk->session },
                { lock_unlock_locking_range_sum, lk_unlk },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
 
-       dev->steps = lk_unlk->session.sum ? unlock_sum_steps : unlock_steps;
-       return next(dev);
+       if (lk_unlk->session.sum)
+               return next(dev, unlock_sum_steps,
+                           ARRAY_SIZE(unlock_sum_steps));
+       else
+               return next(dev, unlock_steps, ARRAY_SIZE(unlock_steps));
 }
 
 static int __opal_set_mbr_done(struct opal_dev *dev, struct opal_key *key)
@@ -2087,12 +2074,10 @@ static int __opal_set_mbr_done(struct opal_dev *dev, struct opal_key *key)
                { opal_discovery0, },
                { start_admin1LSP_opal_session, key },
                { set_mbr_done, &mbr_done_tf },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
 
-       dev->steps = mbrdone_step;
-       return next(dev);
+       return next(dev, mbrdone_step, ARRAY_SIZE(mbrdone_step));
 }
 
 static int opal_lock_unlock(struct opal_dev *dev,
@@ -2119,8 +2104,7 @@ static int opal_take_ownership(struct opal_dev *dev, struct opal_key *opal)
                { end_opal_session, },
                { start_SIDASP_opal_session, opal },
                { set_sid_cpin_pin, opal },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        int ret;
 
@@ -2128,8 +2112,8 @@ static int opal_take_ownership(struct opal_dev *dev, struct opal_key *opal)
                return -ENODEV;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, owner_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, owner_steps, ARRAY_SIZE(owner_steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -2142,8 +2126,7 @@ static int opal_activate_lsp(struct opal_dev *dev,
                { start_SIDASP_opal_session, &opal_lr_act->key },
                { get_lsp_lifecycle, },
                { activate_lsp, opal_lr_act },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        int ret;
 
@@ -2151,8 +2134,8 @@ static int opal_activate_lsp(struct opal_dev *dev,
                return -EINVAL;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, active_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, active_steps, ARRAY_SIZE(active_steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -2164,14 +2147,13 @@ static int opal_setup_locking_range(struct opal_dev *dev,
                { opal_discovery0, },
                { start_auth_opal_session, &opal_lrs->session },
                { setup_locking_range, opal_lrs },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        int ret;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, lr_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, lr_steps, ARRAY_SIZE(lr_steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -2182,8 +2164,7 @@ static int opal_set_new_pw(struct opal_dev *dev, struct opal_new_pw *opal_pw)
                { opal_discovery0, },
                { start_auth_opal_session, &opal_pw->session },
                { set_new_pw, &opal_pw->new_user_pw },
-               { end_opal_session, },
-               { NULL }
+               { end_opal_session, }
        };
        int ret;
 
@@ -2194,8 +2175,8 @@ static int opal_set_new_pw(struct opal_dev *dev, struct opal_new_pw *opal_pw)
                return -EINVAL;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, pw_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, pw_steps, ARRAY_SIZE(pw_steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -2207,8 +2188,7 @@ static int opal_activate_user(struct opal_dev *dev,
                { opal_discovery0, },
                { start_admin1LSP_opal_session, &opal_session->opal_key },
                { internal_activate_user, opal_session },
-               { end_opal_session, },
-               { NULL, }
+               { end_opal_session, }
        };
        int ret;
 
@@ -2220,8 +2200,8 @@ static int opal_activate_user(struct opal_dev *dev,
        }
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, act_steps);
-       ret = next(dev);
+       setup_opal_dev(dev);
+       ret = next(dev, act_steps, ARRAY_SIZE(act_steps));
        mutex_unlock(&dev->dev_lock);
        return ret;
 }
@@ -2238,7 +2218,7 @@ bool opal_unlock_from_suspend(struct opal_dev *dev)
                return false;
 
        mutex_lock(&dev->dev_lock);
-       setup_opal_dev(dev, NULL);
+       setup_opal_dev(dev);
 
        list_for_each_entry(suspend, &dev->unlk_lst, node) {
                dev->tsn = 0;