nfs/blocklayout: refactor open-by-wwn

The current code works with the standard udev/systemd names, but we'll have
to add another method in the next patch.  Refactor it into a separate helper
to make room for the new variant.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Christoph Hellwig 2016-07-08 18:41:29 +09:00 committed by Trond Myklebust
parent 0173ca0544
commit d702d41ed4

View File

@ -287,44 +287,45 @@ 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)
{
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);
if (!devname)
return ERR_PTR(-ENOMEM);
bdev = blkdev_get_by_path(devname, FMODE_READ | FMODE_WRITE, NULL);
if (IS_ERR(bdev)) {
pr_warn("pNFS: failed to open device %s (%ld)\n",
devname, PTR_ERR(bdev));
}
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)
{
struct pnfs_block_volume *v = &volumes[idx];
const struct pr_ops *ops;
const char *devname;
int error;
if (!bl_validate_designator(v))
return -EINVAL;
switch (v->scsi.designator_len) {
case 8:
devname = kasprintf(GFP_KERNEL, "/dev/disk/by-id/wwn-0x%8phN",
v->scsi.designator);
break;
case 12:
devname = kasprintf(GFP_KERNEL, "/dev/disk/by-id/wwn-0x%12phN",
v->scsi.designator);
break;
case 16:
devname = kasprintf(GFP_KERNEL, "/dev/disk/by-id/wwn-0x%16phN",
v->scsi.designator);
break;
default:
return -EINVAL;
}
d->bdev = blkdev_get_by_path(devname, FMODE_READ | FMODE_WRITE, NULL);
if (IS_ERR(d->bdev)) {
pr_warn("pNFS: failed to open device %s (%ld)\n",
devname, PTR_ERR(d->bdev));
kfree(devname);
d->bdev = bl_open_udev_path(v);
if (IS_ERR(d->bdev))
return PTR_ERR(d->bdev);
}
kfree(devname);
d->len = i_size_read(d->bdev->bd_inode);
d->map = bl_map_simple;