Commit 1f014290 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
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block: adjust formatting for large minors and add ext_range sysfs attr 



With extended minors and the soon-to-follow debug feature, large minor
numbers for block devices will be common.  This patch does the
followings to make printouts pretty.

* Adapt print formats such that large minors don't break the
  formatting.

* For extended MAJ:MIN, %02x%02x for MAJ:MIN used in
  printk_all_partitions() doesn't cut it anymore.  Update it such that
  %03x:%05x is used if either MAJ or MIN doesn't fit in %02x.

* Implement ext_range sysfs attribute which shows total minors the
  device can use including both conventional minor space and the
  extended one.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent bcce3de1

block/genhd.c

+34 −11
Original line number Diff line number Diff line
@@ -366,6 +366,18 @@ void blk_free_devt(dev_t devt) 
	}

}



static char *bdevt_str(dev_t devt, char *buf)

{

	if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {

		char tbuf[BDEVT_SIZE];

		snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));

		snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);

	} else

		snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));



	return buf;

}



/*

 * Register device numbers dev..(dev+range-1)

 * range must be nonzero
@@ -521,7 +533,8 @@ void __init printk_all_partitions(void) 
		struct gendisk *disk = dev_to_disk(dev);

		struct disk_part_iter piter;

		struct hd_struct *part;

		char buf[BDEVNAME_SIZE];

		char name_buf[BDEVNAME_SIZE];

		char devt_buf[BDEVT_SIZE];



		/*

		 * Don't show empty devices or things that have been
@@ -536,10 +549,10 @@ void __init printk_all_partitions(void) 
		 * numbers in hex - the same format as the root=

		 * option takes.

		 */

		printk("%02x%02x %10llu %s",

		       MAJOR(disk_devt(disk)), MINOR(disk_devt(disk)),

		printk("%s %10llu %s",

		       bdevt_str(disk_devt(disk), devt_buf),

		       (unsigned long long)get_capacity(disk) >> 1,

		       disk_name(disk, 0, buf));

		       disk_name(disk, 0, name_buf));

		if (disk->driverfs_dev != NULL &&

		    disk->driverfs_dev->driver != NULL)

			printk(" driver: %s\n",
@@ -550,10 +563,10 @@ void __init printk_all_partitions(void) 
		/* now show the partitions */

		disk_part_iter_init(&piter, disk, 0);

		while ((part = disk_part_iter_next(&piter)))

			printk("  %02x%02x %10llu %s\n",

			       MAJOR(part_devt(part)), MINOR(part_devt(part)),

			printk("  %s %10llu %s\n",

			       bdevt_str(part_devt(part), devt_buf),

			       (unsigned long long)part->nr_sects >> 1,

			       disk_name(disk, part->partno, buf));

			       disk_name(disk, part->partno, name_buf));

		disk_part_iter_exit(&piter);

	}

	class_dev_iter_exit(&iter);
@@ -630,14 +643,14 @@ static int show_partition(struct seq_file *seqf, void *v) 
		return 0;



	/* show the full disk and all non-0 size partitions of it */

	seq_printf(seqf, "%4d  %4d %10llu %s\n",

	seq_printf(seqf, "%4d  %7d %10llu %s\n",

		MAJOR(disk_devt(sgp)), MINOR(disk_devt(sgp)),

		(unsigned long long)get_capacity(sgp) >> 1,

		disk_name(sgp, 0, buf));



	disk_part_iter_init(&piter, sgp, 0);

	while ((part = disk_part_iter_next(&piter)))

		seq_printf(seqf, "%4d  %4d %10llu %s\n",

		seq_printf(seqf, "%4d  %7d %10llu %s\n",

			   MAJOR(part_devt(part)), MINOR(part_devt(part)),

			   (unsigned long long)part->nr_sects >> 1,

			   disk_name(sgp, part->partno, buf));
@@ -691,6 +704,14 @@ static ssize_t disk_range_show(struct device *dev, 
	return sprintf(buf, "%d\n", disk->minors);

}



static ssize_t disk_ext_range_show(struct device *dev,

				   struct device_attribute *attr, char *buf)

{

	struct gendisk *disk = dev_to_disk(dev);



	return sprintf(buf, "%d\n", disk_max_parts(disk) + 1);

}



static ssize_t disk_removable_show(struct device *dev,

				   struct device_attribute *attr, char *buf)

{
@@ -780,6 +801,7 @@ static ssize_t disk_fail_store(struct device *dev, 
#endif



static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);

static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);

static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);

static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);

static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
@@ -792,6 +814,7 @@ static struct device_attribute dev_attr_fail = 


static struct attribute *disk_attrs[] = {

	&dev_attr_range.attr,

	&dev_attr_ext_range.attr,

	&dev_attr_removable.attr,

	&dev_attr_ro.attr,

	&dev_attr_size.attr,
@@ -858,7 +881,7 @@ static int diskstats_show(struct seq_file *seqf, void *v) 
	cpu = disk_stat_lock();

	disk_round_stats(cpu, gp);

	disk_stat_unlock();

	seq_printf(seqf, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",

	seq_printf(seqf, "%4d %7d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",

		MAJOR(disk_devt(gp)), MINOR(disk_devt(gp)),

		disk_name(gp, 0, buf),

		disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
@@ -877,7 +900,7 @@ static int diskstats_show(struct seq_file *seqf, void *v) 
		cpu = disk_stat_lock();

		part_round_stats(cpu, hd);

		disk_stat_unlock();

		seq_printf(seqf, "%4d %4d %s %lu %lu %llu "

		seq_printf(seqf, "%4d %7d %s %lu %lu %llu "

			   "%u %lu %lu %llu %u %u %u %u\n",

			   MAJOR(part_devt(hd)), MINOR(part_devt(hd)),

			   disk_name(gp, hd->partno, buf),

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -1685,6 +1685,7 @@ extern void chrdev_show(struct seq_file *,off_t); 


/* fs/block_dev.c */

#define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */

#define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */



#ifdef CONFIG_BLOCK

#define BLKDEV_MAJOR_HASH_SIZE	255

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