With extended minors and the soon-to-follow debug feature, large minor
numbers for block devices will be common. This patch does the
followings.
* 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: Tejun Heo <tj@xxxxxxxxxx>
---
block/genhd.c | 48 ++++++++++++++++++++++++++++++++++++------------
include/linux/fs.h | 1 +
2 files changed, 37 insertions(+), 12 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c
index 97cc5e4..615e0de 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -286,6 +286,18 @@ struct gendisk *get_gendisk(dev_t devt, int *part)
return kobj ? dev_to_disk(dev) : NULL;
}
+static char *bdevt_str(int major, int minor, char *buf)
+{
+ if (major <= 0xff && minor <= 0xff) {
+ char tbuf[BDEVT_SIZE];
+ snprintf(tbuf, BDEVT_SIZE, "%02x%02x", major, minor);
+ snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
+ } else
+ snprintf(buf, BDEVT_SIZE, "%03x:%05x", major, minor);
+
+ return buf;
+}
+
/*
* print a full list of all partitions - intended for places where the root
* filesystem can't be mounted and thus to give the victim some idea of what
@@ -295,7 +307,8 @@ void __init printk_all_partitions(void)
{
struct device *dev;
struct gendisk *sgp;
- char buf[BDEVNAME_SIZE];
+ char devt_buf[BDEVT_SIZE];
+ char name_buf[BDEVNAME_SIZE];
int n;
mutex_lock(&block_class_lock);
@@ -315,10 +328,10 @@ void __init printk_all_partitions(void)
* Note, unlike /proc/partitions, I am showing the numbers in
* hex - the same format as the root= option takes.
*/
- printk("%02x%02x %10llu %s",
- disk_major(sgp), disk_minor(sgp),
+ printk("%s %10llu %s",
+ bdevt_str(disk_major(sgp), disk_minor(sgp), devt_buf),
(unsigned long long)get_capacity(sgp) >> 1,
- disk_name(sgp, 0, buf));
+ disk_name(sgp, 0, name_buf));
if (sgp->driverfs_dev != NULL &&
sgp->driverfs_dev->driver != NULL)
printk(" driver: %s\n",
@@ -333,10 +346,11 @@ void __init printk_all_partitions(void)
if (!part || !part->nr_sects)
continue;
- printk(" %02x%02x %10llu %s\n",
- part_major(part), part_minor(part),
+ printk(" %s %10llu %s\n",
+ bdevt_str(part_major(part), part_minor(part),
+ devt_buf),
(unsigned long long)sgp->part[n]->nr_sects >> 1,
- disk_name(sgp, n + 1, buf));
+ disk_name(sgp, n + 1, name_buf));
}
}
@@ -386,7 +400,7 @@ static int show_partition(struct seq_file *seqf, void *v)
char buf[BDEVNAME_SIZE];
if (&sgp->dev.node == block_class.devices.next)
- seq_puts(seqf, "major minor #blocks name\n\n");
+ seq_puts(seqf, "major minor #blocks name\n\n");
/* Don't show non-partitionable removeable devices or empty devices */
if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
@@ -396,7 +410,7 @@ 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",
disk_major(sgp), disk_minor(sgp),
(unsigned long long)get_capacity(sgp) >> 1,
disk_name(sgp, 0, buf));
@@ -406,7 +420,7 @@ static int show_partition(struct seq_file *seqf, void *v)
continue;
if (part->nr_sects == 0)
continue;
- seq_printf(seqf, "%4d %4d %10llu %s\n",
+ seq_printf(seqf, "%4d %7d %10llu %s\n",
part_major(part), part_minor(part),
(unsigned long long)part->nr_sects >> 1,
disk_name(sgp, n + 1, buf));
@@ -488,6 +502,14 @@ 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)
{
@@ -568,6 +590,7 @@ 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(size, S_IRUGO, disk_size_show, NULL);
static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
@@ -579,6 +602,7 @@ 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_size.attr,
&dev_attr_capability.attr,
@@ -677,7 +701,7 @@ static int diskstats_show(struct seq_file *s, void *v)
preempt_disable();
disk_round_stats(gp);
preempt_enable();
- seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
+ seq_printf(s, "%4d %7d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
disk_major(gp), disk_minor(gp), disk_name(gp, n, buf),
disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
(unsigned long long)disk_stat_read(gp, sectors[0]),
@@ -699,7 +723,7 @@ static int diskstats_show(struct seq_file *s, void *v)
preempt_disable();
part_round_stats(hd);
preempt_enable();
- seq_printf(s, "%4d %4d %s %lu %lu %llu "
+ seq_printf(s, "%4d %7d %s %lu %lu %llu "
"%u %lu %lu %llu %u %u %u %u\n",
part_major(hd), part_minor(hd),
disk_name(gp, n + 1, buf),
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d8e2762..8337243 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1667,6 +1667,7 @@ 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
--
1.5.4.5
--
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