block: fix synchronization and limit check in blk_alloc_devt()

[pandora-kernel.git] / block / genhd.c

diff --git a/block/genhd.c b/block/genhd.c
index 02e9fca..6edf228 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -26,7 +26,7 @@ static DEFINE_MUTEX(block_class_lock);
 struct kobject *block_depr;
 
 /* for extended dynamic devt allocation, currently only one major is used */
-#define MAX_EXT_DEVT           (1 << MINORBITS)
+#define NR_EXT_DEVT            (1 << MINORBITS)
 
 /* For extended devt allocation.  ext_devt_mutex prevents look up
  * results from going away underneath its user.
@@ -36,6 +36,7 @@ static DEFINE_IDR(ext_devt_idr);
 
 static struct device_type disk_type;
 
+static void disk_alloc_events(struct gendisk *disk);
 static void disk_add_events(struct gendisk *disk);
 static void disk_del_events(struct gendisk *disk);
 static void disk_release_events(struct gendisk *disk);
@@ -420,17 +421,18 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
        do {
                if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL))
                        return -ENOMEM;
+               mutex_lock(&ext_devt_mutex);
                rc = idr_get_new(&ext_devt_idr, part, &idx);
+               if (!rc && idx >= NR_EXT_DEVT) {
+                       idr_remove(&ext_devt_idr, idx);
+                       rc = -EBUSY;
+               }
+               mutex_unlock(&ext_devt_mutex);
        } while (rc == -EAGAIN);
 
        if (rc)
                return rc;
 
-       if (idx > MAX_EXT_DEVT) {
-               idr_remove(&ext_devt_idr, idx);
-               return -EBUSY;
-       }
-
        *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
        return 0;
 }
@@ -602,6 +604,8 @@ void add_disk(struct gendisk *disk)
        disk->major = MAJOR(devt);
        disk->first_minor = MINOR(devt);
 
+       disk_alloc_events(disk);
+
        /* Register BDI before referencing it from bdev */
        bdi = &disk->queue->backing_dev_info;
        bdi_register_dev(bdi, disk_devt(disk));
@@ -642,7 +646,6 @@ void del_gendisk(struct gendisk *disk)
        disk_part_iter_exit(&piter);
 
        invalidate_partition(disk, 0);
-       blk_free_devt(disk_to_dev(disk)->devt);
        set_capacity(disk, 0);
        disk->flags &= ~GENHD_FL_UP;
 
@@ -660,6 +663,7 @@ void del_gendisk(struct gendisk *disk)
        if (!sysfs_deprecated)
                sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
        device_del(disk_to_dev(disk));
+       blk_free_devt(disk_to_dev(disk)->devt);
 }
 EXPORT_SYMBOL(del_gendisk);
 
@@ -741,7 +745,7 @@ void __init printk_all_partitions(void)
                struct hd_struct *part;
                char name_buf[BDEVNAME_SIZE];
                char devt_buf[BDEVT_SIZE];
-               u8 uuid[PARTITION_META_INFO_UUIDLTH * 2 + 1];
+               char uuid_buf[PARTITION_META_INFO_UUIDLTH * 2 + 5];
 
                /*
                 * Don't show empty devices or things that have been
@@ -760,14 +764,16 @@ void __init printk_all_partitions(void)
                while ((part = disk_part_iter_next(&piter))) {
                        bool is_part0 = part == &disk->part0;
 
-                       uuid[0] = 0;
+                       uuid_buf[0] = '\0';
                        if (part->info)
-                               part_unpack_uuid(part->info->uuid, uuid);
+                               snprintf(uuid_buf, sizeof(uuid_buf), "%pU",
+                                        part->info->uuid);
 
                        printk("%s%s %10llu %s %s", is_part0 ? "" : "  ",
                               bdevt_str(part_devt(part), devt_buf),
                               (unsigned long long)part->nr_sects >> 1,
-                              disk_name(disk, part->partno, name_buf), uuid);
+                              disk_name(disk, part->partno, name_buf),
+                              uuid_buf);
                        if (is_part0) {
                                if (disk->driverfs_dev != NULL &&
                                    disk->driverfs_dev->driver != NULL)
@@ -1476,9 +1482,9 @@ static void __disk_unblock_events(struct gendisk *disk, bool check_now)
        intv = disk_events_poll_jiffies(disk);
        set_timer_slack(&ev->dwork.timer, intv / 4);
        if (check_now)
-               queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
+               queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
        else if (intv)
-               queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
+               queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, intv);
 out_unlock:
        spin_unlock_irqrestore(&ev->lock, flags);
 }
@@ -1522,7 +1528,7 @@ void disk_flush_events(struct gendisk *disk, unsigned int mask)
        ev->clearing |= mask;
        if (!ev->block) {
                cancel_delayed_work(&ev->dwork);
-               queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
+               queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
        }
        spin_unlock_irq(&ev->lock);
 }
@@ -1559,7 +1565,7 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
 
        /* uncondtionally schedule event check and wait for it to finish */
        disk_block_events(disk);
-       queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
+       queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
        flush_delayed_work(&ev->dwork);
        __disk_unblock_events(disk, false);
 
@@ -1596,7 +1602,7 @@ static void disk_events_workfn(struct work_struct *work)
 
        intv = disk_events_poll_jiffies(disk);
        if (!ev->block && intv)
-               queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
+               queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, intv);
 
        spin_unlock_irq(&ev->lock);
 
@@ -1734,9 +1740,9 @@ module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
                &disk_events_dfl_poll_msecs, 0644);
 
 /*
- * disk_{add|del|release}_events - initialize and destroy disk_events.
+ * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
  */
-static void disk_add_events(struct gendisk *disk)
+static void disk_alloc_events(struct gendisk *disk)
 {
        struct disk_events *ev;
 
@@ -1749,16 +1755,6 @@ static void disk_add_events(struct gendisk *disk)
                return;
        }
 
-       if (sysfs_create_files(&disk_to_dev(disk)->kobj,
-                              disk_events_attrs) < 0) {
-               pr_warn("%s: failed to create sysfs files for events\n",
-                       disk->disk_name);
-               kfree(ev);
-               return;
-       }
-
-       disk->ev = ev;
-
        INIT_LIST_HEAD(&ev->node);
        ev->disk = disk;
        spin_lock_init(&ev->lock);
@@ -1767,8 +1763,21 @@ static void disk_add_events(struct gendisk *disk)
        ev->poll_msecs = -1;
        INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
 
+       disk->ev = ev;
+}
+
+static void disk_add_events(struct gendisk *disk)
+{
+       if (!disk->ev)
+               return;
+
+       /* FIXME: error handling */
+       if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
+               pr_warn("%s: failed to create sysfs files for events\n",
+                       disk->disk_name);
+
        mutex_lock(&disk_events_mutex);
-       list_add_tail(&ev->node, &disk_events);
+       list_add_tail(&disk->ev->node, &disk_events);
        mutex_unlock(&disk_events_mutex);
 
        /*