21 #include <linux/major.h>
54 /* for extended dynamic devt allocation, currently only one major is used */
164 	int major;  member
174 static inline int major_to_index(unsigned major)  in major_to_index()  argument
176 	return major % BLKDEV_MAJOR_HASH_SIZE;  in major_to_index()
186 		if (dp->major == offset)  in blkdev_show()
187 			seq_printf(seqf, "%3d %s\n", dp->major, dp->name);  in blkdev_show()
195  * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
196  *         @major = 0, try to allocate any unused major number.
205  * The return value depends on the @major input parameter:
207  *  - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
209  *  - if any unused major number was requested with @major = 0 parameter
210  *    then the return value is the allocated major number in range
214  * major numbers.
218 int __register_blkdev(unsigned int major, const char *name,  in __register_blkdev()  argument
227 	if (major == 0) {  in __register_blkdev()
234 			printk("%s: failed to get major for %s\n",  in __register_blkdev()
239 		major = index;  in __register_blkdev()
240 		ret = major;  in __register_blkdev()
243 	if (major >= BLKDEV_MAJOR_MAX) {  in __register_blkdev()
244 		pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",  in __register_blkdev()
245 		       __func__, major, BLKDEV_MAJOR_MAX-1, name);  in __register_blkdev()
257 	p->major = major;  in __register_blkdev()
263 	index = major_to_index(major);  in __register_blkdev()
267 		if ((*n)->major == major)  in __register_blkdev()
277 		printk("register_blkdev: cannot get major %u for %s\n",  in __register_blkdev()
278 		       major, name);  in __register_blkdev()
287 void unregister_blkdev(unsigned int major, const char *name)  in unregister_blkdev()  argument
291 	int index = major_to_index(major);  in unregister_blkdev()
296 		if ((*n)->major == major)  in unregister_blkdev()
328 	if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {  in bdevt_str()
330 		snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));  in bdevt_str()
333 		snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));  in bdevt_str()
407 	 * If the driver provides an explicit major number it also must provide  in device_add_disk()
414 	if (disk->major) {  in device_add_disk()
432 		disk->major = BLOCK_EXT_MAJOR;  in device_add_disk()
443 		ddev->devt = MKDEV(disk->major, disk->first_minor);  in device_add_disk()
492 				   disk->major, disk->first_minor);  in device_add_disk()
515 		 * freeing of the dynamic major works.  in device_add_disk()
517 		disk->part0->bd_dev = MKDEV(disk->major, disk->first_minor);  in device_add_disk()
543 	if (disk->major == BLOCK_EXT_MAJOR)  in device_add_disk()
719 	unsigned int major = MAJOR(devt);  in blk_request_module()  local
723 	for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {  in blk_request_module()
724 		if ((*n)->major == major && (*n)->probe) {  in blk_request_module()
732 	if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)  in blk_request_module()
734 		request_module("block-major-%d", MAJOR(devt));  in blk_request_module()
842 		seq_puts(seqf, "major minor  #blocks  name\n\n");  in show_partition_start()
860 			   MAJOR(part->bd_dev), MINOR(part->bd_dev),  in show_partition()
1231 		seq_puts(seqf,	"major minor name"  in diskstats_show()
1259 			   MAJOR(hd->bd_dev), MINOR(hd->bd_dev), hd,  in diskstats_show()
1339 			devt = MKDEV(MAJOR(dev->devt),  in blk_lookup_devt()