Display all possible partitions when the root filesystem failed to mount (dd2a345f) · Commits · 戴 / test

block/genhd.c

+53 −0

Original line number	Diff line number	Diff line
		@@ -213,6 +213,59 @@ struct gendisk get_gendisk(dev_t dev, int part)
		return kobj ? to_disk(kobj) : NULL;
		}

		/*
		* 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
		* went wrong
		*/
		void __init printk_all_partitions(void)
		{
		int n;
		struct gendisk *sgp;

		mutex_lock(&block_subsys_lock);
		/* For each block device... */
		list_for_each_entry(sgp, &block_subsys.list, kobj.entry) {
		char buf[BDEVNAME_SIZE];
		/*
		* Don't show empty devices or things that have been surpressed
		*/
		if (get_capacity(sgp) == 0 \|\|
		(sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
		continue;

		/*
		* Note, unlike /proc/partitions, I am showing the numbers in
		* hex - the same format as the root= option takes.
		*/
		printk("%02x%02x %10llu %s",
		sgp->major, sgp->first_minor,
		(unsigned long long)get_capacity(sgp) >> 1,
		disk_name(sgp, 0, buf));
		if (sgp->driverfs_dev != NULL &&
		sgp->driverfs_dev->driver != NULL)
		printk(" driver: %s\n",
		sgp->driverfs_dev->driver->name);
		else
		printk(" (driver?)\n");

		/* now show the partitions */
		for (n = 0; n < sgp->minors - 1; ++n) {
		if (sgp->part[n] == NULL)
		continue;
		if (sgp->part[n]->nr_sects == 0)
		continue;
		printk(" %02x%02x %10llu %s\n",
		sgp->major, n + 1 + sgp->first_minor,
		(unsigned long long)sgp->part[n]->nr_sects >> 1,
		disk_name(sgp, n + 1, buf));
		} /* partition subloop */
		} /* Block device loop */

		mutex_unlock(&block_subsys_lock);
		return;
		}

		#ifdef CONFIG_PROC_FS
		/* iterator */
		static void part_start(struct seq_file part, loff_t *pos)

include/linux/genhd.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -413,6 +413,7 @@ char disk_name (struct gendisk hd, int part, char *buf);
		extern int rescan_partitions(struct gendisk disk, struct block_device bdev);
		extern void add_partition(struct gendisk *, int, sector_t, sector_t, int);
		extern void delete_partition(struct gendisk *, int);
		extern void printk_all_partitions(void);

		extern struct gendisk *alloc_disk_node(int minors, int node_id);
		extern struct gendisk *alloc_disk(int minors);

init/do_mounts.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@
		#include <linux/root_dev.h>
		#include <linux/security.h>
		#include <linux/delay.h>
		#include <linux/genhd.h>
		#include <linux/mount.h>
		#include <linux/device.h>
		#include <linux/init.h>
		@@ -308,17 +309,21 @@ retry:
		/*
		* Allow the user to distinguish between failed sys_open
		* and bad superblock on root device.
		* and give them a list of the available devices
		*/
		#ifdef CONFIG_BLOCK
		__bdevname(ROOT_DEV, b);
		#endif
		printk("VFS: Cannot open root device \"%s\" or %s\n",
		root_device_name, b);
		printk("Please append a correct \"root=\" boot option\n");
		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");

		printk_all_partitions();
		panic("VFS: Unable to mount root fs on %s", b);
		}

		printk("List of all partitions:\n");
		printk_all_partitions();
		printk("No filesystem could mount root, tried: ");
		for (p = fs_names; *p; p += strlen(p)+1)
		printk(" %s", p);

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