block: allow disk to have extended device number (3e1a7ff8) · Commits · 戴 / test

block/genhd.c

+24 −1

Original line number	Diff line number	Diff line
		@@ -478,14 +478,37 @@ static int exact_lock(dev_t devt, void *data)
		*
		* This function registers the partitioning information in @disk
		* with the kernel.
		*
		* FIXME: error handling
		*/
		void add_disk(struct gendisk *disk)
		{
		struct backing_dev_info *bdi;
		dev_t devt;
		int retval;

		/* minors == 0 indicates to use ext devt from part0 and should
		* be accompanied with EXT_DEVT flag. Make sure all
		* parameters make sense.
		*/
		WARN_ON(disk->minors && !(disk->major \|\| disk->first_minor));
		WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));

		disk->flags \|= GENHD_FL_UP;
		disk_to_dev(disk)->devt = MKDEV(disk->major, disk->first_minor);

		retval = blk_alloc_devt(&disk->part0, &devt);
		if (retval) {
		WARN_ON(1);
		return;
		}
		disk_to_dev(disk)->devt = devt;

		/* ->major and ->first_minor aren't supposed to be
		* dereferenced from here on, but set them just in case.
		*/
		disk->major = MAJOR(devt);
		disk->first_minor = MINOR(devt);

		blk_register_region(disk_devt(disk), disk->minors, NULL,
		exact_match, exact_lock, disk);
		register_disk(disk);

drivers/ide/ide-disk.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -44,7 +44,7 @@
		#if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
		#define IDE_DISK_MINORS (1 << PARTN_BITS)
		#else
		#define IDE_DISK_MINORS 1
		#define IDE_DISK_MINORS 0
		#endif

		struct ide_disk_obj {

drivers/scsi/sd.c

+54 −20

Original line number	Diff line number	Diff line
		@@ -89,7 +89,7 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
		#if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
		#define SD_MINORS 16
		#else
		#define SD_MINORS 1
		#define SD_MINORS 0
		#endif

		static int sd_revalidate_disk(struct gendisk *);
		@@ -1769,6 +1769,52 @@ static int sd_revalidate_disk(struct gendisk *disk)
		return 0;
		}

		/**
		* sd_format_disk_name - format disk name
		* @prefix: name prefix - ie. "sd" for SCSI disks
		* @index: index of the disk to format name for
		* @buf: output buffer
		* @buflen: length of the output buffer
		*
		* SCSI disk names starts at sda. The 26th device is sdz and the
		* 27th is sdaa. The last one for two lettered suffix is sdzz
		* which is followed by sdaaa.
		*
		* This is basically 26 base counting with one extra 'nil' entry
		* at the beggining from the second digit on and can be
		* determined using similar method as 26 base conversion with the
		* index shifted -1 after each digit is computed.
		*
		* CONTEXT:
		* Don't care.
		*
		* RETURNS:
		* 0 on success, -errno on failure.
		*/
		static int sd_format_disk_name(char prefix, int index, char buf, int buflen)
		{
		const int base = 'z' - 'a' + 1;
		char *begin = buf + strlen(prefix);
		char *end = buf + buflen;
		char *p;
		int unit;

		p = end - 1;
		*p = '\0';
		unit = base;
		do {
		if (p == begin)
		return -EINVAL;
		*--p = 'a' + (index % unit);
		index = (index / unit) - 1;
		} while (index >= 0);

		memmove(begin, p, end - p);
		memcpy(buf, prefix, strlen(prefix));

		return 0;
		}

		/**
		* sd_probe - called during driver initialization and whenever a
		* new scsi device is attached to the system. It is called once
		@@ -1821,8 +1867,8 @@ static int sd_probe(struct device *dev)
		if (error)
		goto out_put;

		error = -EBUSY;
		if (index >= SD_MAX_DISKS)
		error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
		if (error)
		goto out_free_index;

		sdkp->device = sdp;
		@@ -1849,24 +1895,12 @@ static int sd_probe(struct device *dev)

		get_device(&sdp->sdev_gendev);

		if (index < SD_MAX_DISKS) {
		gd->major = sd_major((index & 0xf0) >> 4);
		gd->first_minor = ((index & 0xf) << 4) \| (index & 0xfff00);
		gd->minors = SD_MINORS;
		gd->fops = &sd_fops;

		if (index < 26) {
		sprintf(gd->disk_name, "sd%c", 'a' + index % 26);
		} else if (index < (26 + 1) * 26) {
		sprintf(gd->disk_name, "sd%c%c",
		'a' + index / 26 - 1,'a' + index % 26);
		} else {
		const unsigned int m1 = (index / 26 - 1) / 26 - 1;
		const unsigned int m2 = (index / 26 - 1) % 26;
		const unsigned int m3 = index % 26;
		sprintf(gd->disk_name, "sd%c%c%c",
		'a' + m1, 'a' + m2, 'a' + m3);
		}

		gd->fops = &sd_fops;
		gd->private_data = &sdkp->driver;
		gd->queue = sdkp->device->request_queue;

fs/partitions/check.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -593,6 +593,7 @@ void del_gendisk(struct gendisk *disk)
		disk_part_iter_exit(&piter);

		invalidate_partition(disk, 0);
		blk_free_devt(disk_to_dev(disk)->devt);
		set_capacity(disk, 0);
		disk->flags &= ~GENHD_FL_UP;
		unlink_gendisk(disk);

include/linux/genhd.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -59,6 +59,7 @@ enum {
		};

		#define DISK_MAX_PARTS 256
		#define DISK_NAME_LEN 32

		#include <linux/major.h>
		#include <linux/device.h>
		@@ -140,7 +141,7 @@ struct gendisk {
		int minors; /* maximum number of minors, =1 for
		* disks that can't be partitioned. */

		char disk_name[32]; /* name of major driver */
		char disk_name[DISK_NAME_LEN]; /* name of major driver */

		/* Array of pointers to partitions indexed by partno.
		* Protected with matching bdev lock but stat and other

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