block: fix ext_dev_lock lockdep report

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / block / genhd.c

diff --git a/block/genhd.c b/block/genhd.c
index 20625eed55116555216cb594c49e4a0c36049675..b09f5fc94dee3f8cb2de7e277f82098a9d95b02c 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -28,10 +28,10 @@ struct kobject *block_depr;
 /* for extended dynamic devt allocation, currently only one major is used */
 #define NR_EXT_DEVT            (1 << MINORBITS)
 
-/* For extended devt allocation.  ext_devt_mutex prevents look up
+/* For extended devt allocation.  ext_devt_lock prevents look up
  * results from going away underneath its user.
  */
-static DEFINE_MUTEX(ext_devt_mutex);
+static DEFINE_SPINLOCK(ext_devt_lock);
 static DEFINE_IDR(ext_devt_idr);
 
 static struct device_type disk_type;
@@ -420,9 +420,13 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
        }
 
        /* allocate ext devt */
-       mutex_lock(&ext_devt_mutex);
-       idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_KERNEL);
-       mutex_unlock(&ext_devt_mutex);
+       idr_preload(GFP_KERNEL);
+
+       spin_lock_bh(&ext_devt_lock);
+       idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
+       spin_unlock_bh(&ext_devt_lock);
+
+       idr_preload_end();
        if (idx < 0)
                return idx == -ENOSPC ? -EBUSY : idx;
 
@@ -441,15 +445,13 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
  */
 void blk_free_devt(dev_t devt)
 {
-       might_sleep();
-
        if (devt == MKDEV(0, 0))
                return;
 
        if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
-               mutex_lock(&ext_devt_mutex);
+               spin_lock_bh(&ext_devt_lock);
                idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
-               mutex_unlock(&ext_devt_mutex);
+               spin_unlock_bh(&ext_devt_lock);
        }
 }
 
@@ -512,7 +514,7 @@ static void register_disk(struct gendisk *disk)
 
        ddev->parent = disk->driverfs_dev;
 
-       dev_set_name(ddev, disk->disk_name);
+       dev_set_name(ddev, "%s", disk->disk_name);
 
        /* delay uevents, until we scanned partition table */
        dev_set_uevent_suppress(ddev, 1);
@@ -665,7 +667,6 @@ void del_gendisk(struct gendisk *disk)
                sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
        pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
        device_del(disk_to_dev(disk));
-       blk_free_devt(disk_to_dev(disk)->devt);
 }
 EXPORT_SYMBOL(del_gendisk);
 
@@ -690,13 +691,13 @@ struct gendisk *get_gendisk(dev_t devt, int *partno)
        } else {
                struct hd_struct *part;
 
-               mutex_lock(&ext_devt_mutex);
+               spin_lock_bh(&ext_devt_lock);
                part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
                if (part && get_disk(part_to_disk(part))) {
                        *partno = part->partno;
                        disk = part_to_disk(part);
                }
-               mutex_unlock(&ext_devt_mutex);
+               spin_unlock_bh(&ext_devt_lock);
        }
 
        return disk;
@@ -1069,9 +1070,16 @@ int disk_expand_part_tbl(struct gendisk *disk, int partno)
        struct disk_part_tbl *old_ptbl = disk->part_tbl;
        struct disk_part_tbl *new_ptbl;
        int len = old_ptbl ? old_ptbl->len : 0;
-       int target = partno + 1;
+       int i, target;
        size_t size;
-       int i;
+
+       /*
+        * check for int overflow, since we can get here from blkpg_ioctl()
+        * with a user passed 'partno'.
+        */
+       target = partno + 1;
+       if (target < 0)
+               return -EINVAL;
 
        /* disk_max_parts() is zero during initialization, ignore if so */
        if (disk_max_parts(disk) && target > disk_max_parts(disk))
@@ -1098,6 +1106,7 @@ static void disk_release(struct device *dev)
 {
        struct gendisk *disk = dev_to_disk(dev);
 
+       blk_free_devt(dev->devt);
        disk_release_events(disk);
        kfree(disk->random);
        disk_replace_part_tbl(disk, NULL);