Commit c2637e80 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

init: refactor name_to_dev_t 



Split each case into a self-contained helper, and move the block
dependent code entirely under the pre-existing #ifdef CONFIG_BLOCK.
This allows to remove the blk_lookup_devt stub in genhd.h.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3a4174e6

include/linux/genhd.h

+1 −6
Original line number Diff line number Diff line
@@ -388,18 +388,13 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev, 
}

#endif /* CONFIG_SYSFS */



dev_t blk_lookup_devt(const char *name, int partno);

#ifdef CONFIG_BLOCK

void printk_all_partitions(void);

dev_t blk_lookup_devt(const char *name, int partno);

#else /* CONFIG_BLOCK */

static inline void printk_all_partitions(void)

{

}

static inline dev_t blk_lookup_devt(const char *name, int partno)

{

	dev_t devt = MKDEV(0, 0);

	return devt;

}

#endif /* CONFIG_BLOCK */



#endif /* _LINUX_GENHD_H */

init/do_mounts.c

+90 −93
Original line number Diff line number Diff line
@@ -90,7 +90,6 @@ no_match: 
	return 0;

}





/**

 * devt_from_partuuid - looks up the dev_t of a partition by its UUID

 * @uuid_str:	char array containing ascii UUID
@@ -186,7 +185,83 @@ static int match_dev_by_label(struct device *dev, const void *data) 


	return 0;

}

#endif



static dev_t devt_from_partlabel(const char *label)

{

	struct device *dev;

	dev_t devt = 0;



	dev = class_find_device(&block_class, NULL, label, &match_dev_by_label);

	if (dev) {

		devt = dev->devt;

		put_device(dev);

	}



	return devt;

}



static dev_t devt_from_devname(const char *name)

{

	dev_t devt = 0;

	int part;

	char s[32];

	char *p;



	if (strlen(name) > 31)

		return 0;

	strcpy(s, name);

	for (p = s; *p; p++) {

		if (*p == '/')

			*p = '!';

	}



	devt = blk_lookup_devt(s, 0);

	if (devt)

		return devt;



	/*

	 * Try non-existent, but valid partition, which may only exist after

	 * opening the device, like partitioned md devices.

	 */

	while (p > s && isdigit(p[-1]))

		p--;

	if (p == s || !*p || *p == '0')

		return 0;



	/* try disk name without <part number> */

	part = simple_strtoul(p, NULL, 10);

	*p = '\0';

	devt = blk_lookup_devt(s, part);

	if (devt)

		return devt;



	/* try disk name without p<part number> */

	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')

		return 0;

	p[-1] = '\0';

	return blk_lookup_devt(s, part);

}

#endif /* CONFIG_BLOCK */



static dev_t devt_from_devnum(const char *name)

{

	unsigned maj, min, offset;

	dev_t devt = 0;

	char *p, dummy;



	if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||

	    sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3) {

		devt = MKDEV(maj, min);

		if (maj != MAJOR(devt) || min != MINOR(devt))

			return 0;

	} else {

		devt = new_decode_dev(simple_strtoul(name, &p, 16));

		if (*p)

			return 0;

	}



	return devt;

}



/*

 *	Convert a name into device number.  We accept the following variants:
@@ -218,101 +293,23 @@ static int match_dev_by_label(struct device *dev, const void *data) 
 *	name contains slashes, the device name has them replaced with

 *	bangs.

 */



dev_t name_to_dev_t(const char *name)

{

	char s[32];

	char *p;

	dev_t res = 0;

	int part;



	if (strcmp(name, "/dev/nfs") == 0)

		return Root_NFS;

	if (strcmp(name, "/dev/cifs") == 0)

		return Root_CIFS;

	if (strcmp(name, "/dev/ram") == 0)

		return Root_RAM0;

#ifdef CONFIG_BLOCK

	if (strncmp(name, "PARTUUID=", 9) == 0) {

		name += 9;

		res = devt_from_partuuid(name);

		if (!res)

			goto fail;

		goto done;

	} else if (strncmp(name, "PARTLABEL=", 10) == 0) {

		struct device *dev;



		dev = class_find_device(&block_class, NULL, name + 10,

					&match_dev_by_label);

		if (!dev)

			goto fail;



		res = dev->devt;

		put_device(dev);

		goto done;

	}

	if (strncmp(name, "PARTUUID=", 9) == 0)

		return devt_from_partuuid(name + 9);

	if (strncmp(name, "PARTLABEL=", 10) == 0)

		return devt_from_partlabel(name + 10);

	if (strncmp(name, "/dev/", 5) == 0)

		return devt_from_devname(name + 5);

#endif



	if (strncmp(name, "/dev/", 5) != 0) {

		unsigned maj, min, offset;

		char dummy;



		if ((sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2) ||

		    (sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3)) {

			res = MKDEV(maj, min);

			if (maj != MAJOR(res) || min != MINOR(res))

				goto fail;

		} else {

			res = new_decode_dev(simple_strtoul(name, &p, 16));

			if (*p)

				goto fail;

		}

		goto done;

	}



	name += 5;

	res = Root_NFS;

	if (strcmp(name, "nfs") == 0)

		goto done;

	res = Root_CIFS;

	if (strcmp(name, "cifs") == 0)

		goto done;

	res = Root_RAM0;

	if (strcmp(name, "ram") == 0)

		goto done;



	if (strlen(name) > 31)

		goto fail;

	strcpy(s, name);

	for (p = s; *p; p++)

		if (*p == '/')

			*p = '!';

	res = blk_lookup_devt(s, 0);

	if (res)

		goto done;



	/*

	 * try non-existent, but valid partition, which may only exist

	 * after revalidating the disk, like partitioned md devices

	 */

	while (p > s && isdigit(p[-1]))

		p--;

	if (p == s || !*p || *p == '0')

		goto fail;



	/* try disk name without <part number> */

	part = simple_strtoul(p, NULL, 10);

	*p = '\0';

	res = blk_lookup_devt(s, part);

	if (res)

		goto done;



	/* try disk name without p<part number> */

	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')

		goto fail;

	p[-1] = '\0';

	res = blk_lookup_devt(s, part);

	if (res)

		goto done;



fail:

	return 0;

done:

	return res;

	return devt_from_devnum(name);

}

EXPORT_SYMBOL_GPL(name_to_dev_t);

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