Merge tag 'nfs-for-5.20-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - pNFS/flexfiles: Fix infinite looping when the RDMA connection
     errors out

  Bugfixes:
   - NFS: fix port value parsing
   - SUNRPC: Reinitialise the backchannel request buffers before reuse
   - SUNRPC: fix expiry of auth creds
   - NFSv4: Fix races in the legacy idmapper upcall
   - NFS: O_DIRECT fixes from Jeff Layton
   - NFSv4.1: Fix OP_SEQUENCE error handling
   - SUNRPC: Fix an RPC/RDMA performance regression
   - NFS: Fix case insensitive renames
   - NFSv4/pnfs: Fix a use-after-free bug in open
   - NFSv4.1: RECLAIM_COMPLETE must handle EACCES

  Features:
   - NFSv4.1: session trunking enhancements
   - NFSv4.2: READ_PLUS performance optimisations
   - NFS: relax the rules for rsize/wsize mount options
   - NFS: don't unhash dentry during unlink/rename
   - SUNRPC: Fail faster on bad verifier
   - NFS/SUNRPC: Various tracing improvements"

* tag 'nfs-for-5.20-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (46 commits)
  NFS: Improve readpage/writepage tracing
  NFS: Improve O_DIRECT tracing
  NFS: Improve write error tracing
  NFS: don't unhash dentry during unlink/rename
  NFSv4/pnfs: Fix a use-after-free bug in open
  NFS: nfs_async_write_reschedule_io must not recurse into the writeback code
  SUNRPC: Don't reuse bvec on retransmission of the request
  SUNRPC: Reinitialise the backchannel request buffers before reuse
  NFSv4.1: RECLAIM_COMPLETE must handle EACCES
  NFSv4.1 probe offline transports for trunking on session creation
  SUNRPC create a function that probes only offline transports
  SUNRPC export xprt_iter_rewind function
  SUNRPC restructure rpc_clnt_setup_test_and_add_xprt
  NFSv4.1 remove xprt from xprt_switch if session trunking test fails
  SUNRPC create an rpc function that allows xprt removal from rpc_clnt
  SUNRPC enable back offline transports in trunking discovery
  SUNRPC create an iterator to list only OFFLINE xprts
  NFSv4.1 offline trunkable transports on DESTROY_SESSION
  SUNRPC add function to offline remove trunkable transports
  SUNRPC expose functions for offline remote xprt functionality
  ...

1 files changed, 11 insertions, 31 deletions

diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c
index 5e56da748b2a..fea5f8821da5 100644
--- a/fs/nfs/blocklayout/dev.c
+++ b/fs/nfs/blocklayout/dev.c
@@ -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;