block: refactor device number setup in __device_add_disk (7c3f828b) · Commits · EulixOS / Software / Kernel

block/blk.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -343,8 +343,8 @@ static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
		static inline void blk_queue_clear_zone_settings(struct request_queue *q) {}
		#endif

		int blk_alloc_devt(struct block_device part, dev_t devt);
		void blk_free_devt(dev_t devt);
		int blk_alloc_ext_minor(void);
		void blk_free_ext_minor(unsigned int minor);
		char disk_name(struct gendisk hd, int partno, char *buf);
		#define ADDPART_FLAG_NONE 0
		#define ADDPART_FLAG_RAID 1

block/genhd.c

+36 −60

Original line number	Diff line number	Diff line
		@@ -333,52 +333,22 @@ static int blk_mangle_minor(int minor)
		return minor;
		}

		/**
		* blk_alloc_devt - allocate a dev_t for a block device
		* @bdev: block device to allocate dev_t for
		* @devt: out parameter for resulting dev_t
		*
		* Allocate a dev_t for block device.
		*
		* RETURNS:
		* 0 on success, allocated dev_t is returned in *@devt. -errno on
		* failure.
		*
		* CONTEXT:
		* Might sleep.
		*/
		int blk_alloc_devt(struct block_device bdev, dev_t devt)
		int blk_alloc_ext_minor(void)
		{
		struct gendisk *disk = bdev->bd_disk;
		int idx;

		/* in consecutive minor range? */
		if (bdev->bd_partno < disk->minors) {
		*devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
		return 0;
		}

		idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT, GFP_KERNEL);
		if (idx < 0)
		return idx == -ENOSPC ? -EBUSY : idx;

		*devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
		return 0;
		if (idx < 0) {
		if (idx == -ENOSPC)
		return -EBUSY;
		return idx;
		}
		return blk_mangle_minor(idx);
		}

		/**
		* blk_free_devt - free a dev_t
		* @devt: dev_t to free
		*
		* Free @devt which was allocated using blk_alloc_devt().
		*
		* CONTEXT:
		* Might sleep.
		*/
		void blk_free_devt(dev_t devt)
		void blk_free_ext_minor(unsigned int minor)
		{
		if (MAJOR(devt) == BLOCK_EXT_MAJOR)
		ida_free(&ext_devt_ida, blk_mangle_minor(MINOR(devt)));
		ida_free(&ext_devt_ida, blk_mangle_minor(minor));
		}

		static char bdevt_str(dev_t devt, char buf)
		@@ -499,8 +469,7 @@ static void __device_add_disk(struct device parent, struct gendisk disk,
		const struct attribute_group **groups,
		bool register_queue)
		{
		dev_t devt;
		int retval;
		int ret;

		/*
		* The disk queue should now be all set with enough information about
		@@ -511,23 +480,29 @@ static void __device_add_disk(struct device parent, struct gendisk disk,
		if (register_queue)
		elevator_init_mq(disk->queue);

		/* minors == 0 indicates to use ext devt from part0 and should
		* be accompanied with EXT_DEVT flag. Make sure all
		* parameters make sense.
		/*
		* If the driver provides an explicit major number it also must provide
		* the number of minors numbers supported, and those will be used to
		* setup the gendisk.
		* Otherwise just allocate the device numbers for both the whole device
		* and all partitions from the extended dev_t space.
		*/
		WARN_ON(disk->minors && !(disk->major \|\| disk->first_minor));
		WARN_ON(!disk->minors &&
		!(disk->flags & (GENHD_FL_EXT_DEVT \| GENHD_FL_HIDDEN)));

		disk->flags \|= GENHD_FL_UP;
		if (disk->major) {
		WARN_ON(!disk->minors);
		} else {
		WARN_ON(disk->minors);
		WARN_ON(!(disk->flags & (GENHD_FL_EXT_DEVT \| GENHD_FL_HIDDEN)));

		retval = blk_alloc_devt(disk->part0, &devt);
		if (retval) {
		ret = blk_alloc_ext_minor();
		if (ret < 0) {
		WARN_ON(1);
		return;
		}
		disk->major = MAJOR(devt);
		disk->first_minor = MINOR(devt);
		disk->major = BLOCK_EXT_MAJOR;
		disk->first_minor = MINOR(ret);
		}

		disk->flags \|= GENHD_FL_UP;

		disk_alloc_events(disk);

		@@ -541,14 +516,14 @@ static void __device_add_disk(struct device parent, struct gendisk disk,
		} else {
		struct backing_dev_info *bdi = disk->queue->backing_dev_info;
		struct device *dev = disk_to_dev(disk);
		int ret;

		/* Register BDI before referencing it from bdev */
		dev->devt = devt;
		ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
		dev->devt = MKDEV(disk->major, disk->first_minor);
		ret = bdi_register(bdi, "%u:%u",
		disk->major, disk->first_minor);
		WARN_ON(ret);
		bdi_set_owner(bdi, dev);
		bdev_add(disk->part0, devt);
		bdev_add(disk->part0, dev->devt);
		}
		register_disk(parent, disk, groups);
		if (register_queue)
		@@ -1120,7 +1095,8 @@ static void disk_release(struct device *dev)

		might_sleep();

		blk_free_devt(dev->devt);
		if (MAJOR(dev->devt) == BLOCK_EXT_MAJOR)
		blk_free_ext_minor(MINOR(dev->devt));
		disk_release_events(disk);
		kfree(disk->random);
		xa_destroy(&disk->part_tbl);

block/partitions/core.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -260,7 +260,8 @@ static const struct attribute_group *part_attr_groups[] = {

		static void part_release(struct device *dev)
		{
		blk_free_devt(dev->devt);
		if (MAJOR(dev->devt) == BLOCK_EXT_MAJOR)
		blk_free_ext_minor(MINOR(dev->devt));
		bdput(dev_to_bdev(dev));
		}

		@@ -379,9 +380,15 @@ static struct block_device add_partition(struct gendisk disk, int partno,
		pdev->type = &part_type;
		pdev->parent = ddev;

		err = blk_alloc_devt(bdev, &devt);
		if (err)
		/* in consecutive minor range? */
		if (bdev->bd_partno < disk->minors) {
		devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
		} else {
		err = blk_alloc_ext_minor();
		if (err < 0)
		goto out_put;
		devt = MKDEV(BLOCK_EXT_MAJOR, err);
		}
		pdev->devt = devt;

		/* delay uevent until 'holders' subdir is created */