From 11487ddbdb12c36e094bedcc5c906ff219905a03 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 8 Jul 2016 18:41:30 +0900 Subject: [PATCH] nfs/blocklayout: support RH/Fedora dm-mpath device nodes Instead of reusing the wwn-* names for multipath devices nodes RHEL and Fedora introduce new dm-mpath-uuid-* nodes with a slightly different naming scheme. Try these names first to ensure we always get a multipath-capable device if it exists. Signed-off-by: Christoph Hellwig Signed-off-by: Trond Myklebust --- fs/nfs/blocklayout/dev.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c index ea70883a174a..436bb303d856 100644 --- a/fs/nfs/blocklayout/dev.c +++ b/fs/nfs/blocklayout/dev.c @@ -312,6 +312,28 @@ 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) @@ -323,7 +345,9 @@ bl_parse_scsi(struct nfs_server *server, struct pnfs_block_dev *d, if (!bl_validate_designator(v)) return -EINVAL; - d->bdev = bl_open_udev_path(v); + d->bdev = bl_open_dm_mpath_udev_path(v); + if (IS_ERR(d->bdev)) + d->bdev = bl_open_udev_path(v); if (IS_ERR(d->bdev)) return PTR_ERR(d->bdev); -- 2.39.5