Commit f931d837 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Trond Myklebust
Browse files

nfs/blocklayout: refactor block device opening 



Deduplicate the helpers to open a device node by passing a name
prefix argument and using the same helper for both kinds of paths.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 7ccafd4b

fs/nfs/blocklayout/dev.c

+11 −31
Original line number Diff line number Diff line
@@ -301,18 +301,14 @@ bl_validate_designator(struct pnfs_block_volume *v) 
	}

}



/*

 * Try to open the udev path for the WWN.  At least on Debian the udev

 * by-id path will always point to the dm-multipath device if one exists.

 */

static struct block_device *

bl_open_udev_path(struct pnfs_block_volume *v)

bl_open_path(struct pnfs_block_volume *v, const char *prefix)

{

	struct block_device *bdev;

	const char *devname;



	devname = kasprintf(GFP_KERNEL, "/dev/disk/by-id/wwn-0x%*phN",

				v->scsi.designator_len, v->scsi.designator);

	devname = kasprintf(GFP_KERNEL, "/dev/disk/by-id/%s%*phN",

			prefix, v->scsi.designator_len, v->scsi.designator);

	if (!devname)

		return ERR_PTR(-ENOMEM);
@@ -326,28 +322,6 @@ bl_open_udev_path(struct pnfs_block_volume *v) 
	return bdev;

}



/*

 * Try to open the RH/Fedora specific dm-mpath udev path for this WWN, as the

 * wwn- links will only point to the first discovered SCSI device there.

 */

static struct block_device *

bl_open_dm_mpath_udev_path(struct pnfs_block_volume *v)

{

	struct block_device *bdev;

	const char *devname;



	devname = kasprintf(GFP_KERNEL,

			"/dev/disk/by-id/dm-uuid-mpath-%d%*phN",

			v->scsi.designator_type,

			v->scsi.designator_len, v->scsi.designator);

	if (!devname)

		return ERR_PTR(-ENOMEM);



	bdev = blkdev_get_by_path(devname, FMODE_READ | FMODE_WRITE, NULL);

	kfree(devname);

	return bdev;

}



static int

bl_parse_scsi(struct nfs_server *server, struct pnfs_block_dev *d,

		struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
@@ -360,9 +334,15 @@ bl_parse_scsi(struct nfs_server *server, struct pnfs_block_dev *d, 
	if (!bl_validate_designator(v))

		return -EINVAL;



	bdev = bl_open_dm_mpath_udev_path(v);

	/*

	 * Try to open the RH/Fedora specific dm-mpath udev path first, as the

	 * wwn- links will only point to the first discovered SCSI device there.

	 * On other distributions like Debian, the default SCSI by-id path will

	 * point to the dm-multipath device if one exists.

	 */

	bdev = bl_open_path(v, "dm-uuid-mpath-0x");

	if (IS_ERR(bdev))

		bdev = bl_open_udev_path(v);

		bdev = bl_open_path(v, "wwn-0x");

	if (IS_ERR(bdev))

		return PTR_ERR(bdev);

	d->bdev = bdev;