vio: fix reuse of vio_dring slot
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / block / rbd.c
index 10c45e101c97f4ae3426d0aa5cd33af7c635c231..9951e66b85028a450e63ba092f9da428d2cb3165 100644 (file)
@@ -937,12 +937,14 @@ static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
                                        u64 snap_id)
 {
        u32 which;
+       const char *snap_name;
 
        which = rbd_dev_snap_index(rbd_dev, snap_id);
        if (which == BAD_SNAP_INDEX)
-               return NULL;
+               return ERR_PTR(-ENOENT);
 
-       return _rbd_dev_v1_snap_name(rbd_dev, which);
+       snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
+       return snap_name ? snap_name : ERR_PTR(-ENOMEM);
 }
 
 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
@@ -1383,6 +1385,14 @@ static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
        return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
 }
 
+static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
+{
+       struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
+
+       return obj_request->img_offset <
+           round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));
+}
+
 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
 {
        dout("%s: obj %p (was %d)\n", __func__, obj_request,
@@ -1399,6 +1409,13 @@ static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
        kref_put(&obj_request->kref, rbd_obj_request_destroy);
 }
 
+static void rbd_img_request_get(struct rbd_img_request *img_request)
+{
+       dout("%s: img %p (was %d)\n", __func__, img_request,
+            atomic_read(&img_request->kref.refcount));
+       kref_get(&img_request->kref);
+}
+
 static bool img_request_child_test(struct rbd_img_request *img_request);
 static void rbd_parent_request_destroy(struct kref *kref);
 static void rbd_img_request_destroy(struct kref *kref);
@@ -2152,6 +2169,7 @@ static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
        img_request->next_completion = which;
 out:
        spin_unlock_irq(&img_request->completion_lock);
+       rbd_img_request_put(img_request);
 
        if (!more)
                rbd_img_request_complete(img_request);
@@ -2213,6 +2231,11 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
                rbd_segment_name_free(object_name);
                if (!obj_request)
                        goto out_unwind;
+               /*
+                * set obj_request->img_request before creating the
+                * osd_request so that it gets the right snapc
+                */
+               rbd_img_obj_request_add(img_request, obj_request);
 
                if (type == OBJ_REQUEST_BIO) {
                        unsigned int clone_size;
@@ -2243,6 +2266,7 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
                        goto out_partial;
                obj_request->osd_req = osd_req;
                obj_request->callback = rbd_img_obj_callback;
+               rbd_img_request_get(img_request);
 
                osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
                                                0, 0);
@@ -2254,11 +2278,6 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
                                        obj_request->pages, length,
                                        offset & ~PAGE_MASK, false, false);
 
-               /*
-                * set obj_request->img_request before formatting
-                * the osd_request so that it gets the right snapc
-                */
-               rbd_img_obj_request_add(img_request, obj_request);
                if (write_request)
                        rbd_osd_req_format_write(obj_request);
                else
@@ -2276,7 +2295,7 @@ out_partial:
        rbd_obj_request_put(obj_request);
 out_unwind:
        for_each_obj_request_safe(img_request, obj_request, next_obj_request)
-               rbd_obj_request_put(obj_request);
+               rbd_img_obj_request_del(img_request, obj_request);
 
        return -ENOMEM;
 }
@@ -2671,7 +2690,7 @@ static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
         */
        if (!img_request_write_test(img_request) ||
                !img_request_layered_test(img_request) ||
-               rbd_dev->parent_overlap <= obj_request->img_offset ||
+               !obj_request_overlaps_parent(obj_request) ||
                ((known = obj_request_known_test(obj_request)) &&
                        obj_request_exists_test(obj_request))) {
 
@@ -2819,7 +2838,7 @@ out_err:
        obj_request_done_set(obj_request);
 }
 
-static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
+static int rbd_obj_notify_ack_sync(struct rbd_device *rbd_dev, u64 notify_id)
 {
        struct rbd_obj_request *obj_request;
        struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
@@ -2834,16 +2853,17 @@ static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
        obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
        if (!obj_request->osd_req)
                goto out;
-       obj_request->callback = rbd_obj_request_put;
 
        osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
                                        notify_id, 0, 0);
        rbd_osd_req_format_read(obj_request);
 
        ret = rbd_obj_request_submit(osdc, obj_request);
-out:
        if (ret)
-               rbd_obj_request_put(obj_request);
+               goto out;
+       ret = rbd_obj_request_wait(obj_request);
+out:
+       rbd_obj_request_put(obj_request);
 
        return ret;
 }
@@ -2863,7 +2883,7 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
        if (ret)
                rbd_warn(rbd_dev, ": header refresh error (%d)\n", ret);
 
-       rbd_obj_notify_ack(rbd_dev, notify_id);
+       rbd_obj_notify_ack_sync(rbd_dev, notify_id);
 }
 
 /*
@@ -3207,7 +3227,7 @@ static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
        page_count = (u32) calc_pages_for(offset, length);
        pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
        if (IS_ERR(pages))
-               ret = PTR_ERR(pages);
+               return PTR_ERR(pages);
 
        ret = -ENOMEM;
        obj_request = rbd_obj_request_create(object_name, offset, length,
@@ -3335,6 +3355,31 @@ static void rbd_exists_validate(struct rbd_device *rbd_dev)
                clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
 }
 
+static void rbd_dev_update_size(struct rbd_device *rbd_dev)
+{
+       sector_t size;
+       bool removing;
+
+       /*
+        * Don't hold the lock while doing disk operations,
+        * or lock ordering will conflict with the bdev mutex via:
+        * rbd_add() -> blkdev_get() -> rbd_open()
+        */
+       spin_lock_irq(&rbd_dev->lock);
+       removing = test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
+       spin_unlock_irq(&rbd_dev->lock);
+       /*
+        * If the device is being removed, rbd_dev->disk has
+        * been destroyed, so don't try to update its size
+        */
+       if (!removing) {
+               size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
+               dout("setting size to %llu sectors", (unsigned long long)size);
+               set_capacity(rbd_dev->disk, size);
+               revalidate_disk(rbd_dev->disk);
+       }
+}
+
 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
 {
        u64 mapping_size;
@@ -3353,12 +3398,7 @@ static int rbd_dev_refresh(struct rbd_device *rbd_dev)
        rbd_exists_validate(rbd_dev);
        mutex_unlock(&ctl_mutex);
        if (mapping_size != rbd_dev->mapping.size) {
-               sector_t size;
-
-               size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
-               dout("setting size to %llu sectors", (unsigned long long)size);
-               set_capacity(rbd_dev->disk, size);
-               revalidate_disk(rbd_dev->disk);
+               rbd_dev_update_size(rbd_dev);
        }
 
        return ret;
@@ -3712,12 +3752,14 @@ static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
        if (ret < sizeof (size_buf))
                return -ERANGE;
 
-       if (order)
+       if (order) {
                *order = size_buf.order;
+               dout("  order %u", (unsigned int)*order);
+       }
        *snap_size = le64_to_cpu(size_buf.size);
 
-       dout("  snap_id 0x%016llx order = %u, snap_size = %llu\n",
-               (unsigned long long)snap_id, (unsigned int)*order,
+       dout("  snap_id 0x%016llx snap_size = %llu\n",
+               (unsigned long long)snap_id,
                (unsigned long long)*snap_size);
 
        return 0;
@@ -4032,8 +4074,13 @@ static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
 
                snap_id = snapc->snaps[which];
                snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
-               if (IS_ERR(snap_name))
-                       break;
+               if (IS_ERR(snap_name)) {
+                       /* ignore no-longer existing snapshots */
+                       if (PTR_ERR(snap_name) == -ENOENT)
+                               continue;
+                       else
+                               break;
+               }
                found = !strcmp(name, snap_name);
                kfree(snap_name);
        }
@@ -4112,8 +4159,8 @@ static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
        /* Look up the snapshot name, and make a copy */
 
        snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
-       if (!snap_name) {
-               ret = -ENOMEM;
+       if (IS_ERR(snap_name)) {
+               ret = PTR_ERR(snap_name);
                goto out_err;
        }
 
@@ -5144,10 +5191,23 @@ static ssize_t rbd_remove(struct bus_type *bus,
        if (ret < 0 || already)
                goto done;
 
-       rbd_bus_del_dev(rbd_dev);
        ret = rbd_dev_header_watch_sync(rbd_dev, false);
        if (ret)
                rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);
+
+       /*
+        * flush remaining watch callbacks - these must be complete
+        * before the osd_client is shutdown
+        */
+       dout("%s: flushing notifies", __func__);
+       ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
+       /*
+        * Don't free anything from rbd_dev->disk until after all
+        * notifies are completely processed. Otherwise
+        * rbd_bus_del_dev() will race with rbd_watch_cb(), resulting
+        * in a potential use after free of rbd_dev->disk or rbd_dev.
+        */
+       rbd_bus_del_dev(rbd_dev);
        rbd_dev_image_release(rbd_dev);
        module_put(THIS_MODULE);
        ret = count;