nfs/blocklayout: add SCSI layout support

This is a trivial extension to the block layout driver to support the
new SCSI layouts draft.  There are three changes:

 - device identifcation through the SCSI VPD page.  This allows us to
   directly use the udev generated persistent device names instead of
   requiring an expensive lookup by crawling every block device node
   in /dev and reading a signature for it.
 - use of SCSI persistent reservations to protect device access and
   allow for robust fencing.  On the client sides this just means
   registering and unregistering a server supplied key.
 - an optimized LAYOUTCOMMIT payload that doesn't send unessecary
   fields to the server.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index c556640..bc21205 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -55,7 +55,6 @@ struct pnfs_block_dev;
  */
 #define PNFS_BLOCK_UUID_LEN	128
 
-
 struct pnfs_block_volume {
 	enum pnfs_block_volume_type	type;
 	union {
@@ -82,6 +81,13 @@ struct pnfs_block_volume {
 			u32		volumes_count;
 			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
 		} stripe;
+		struct {
+			enum scsi_code_set		code_set;
+			enum scsi_designator_type	designator_type;
+			int				designator_len;
+			u8				designator[256];
+			u64				pr_key;
+		} scsi;
 	};
 };
 
@@ -106,6 +112,9 @@ struct pnfs_block_dev {
 	struct block_device		*bdev;
 	u64				disk_offset;
 
+	u64				pr_key;
+	bool				pr_registered;
+
 	bool (*map)(struct pnfs_block_dev *dev, u64 offset,
 			struct pnfs_block_dev_map *map);
 };
@@ -131,6 +140,7 @@ struct pnfs_block_layout {
 	struct rb_root		bl_ext_rw;
 	struct rb_root		bl_ext_ro;
 	spinlock_t		bl_ext_lock;   /* Protects list manipulation */
+	bool			bl_scsi_layout;
 };
 
 static inline struct pnfs_block_layout *
@@ -182,6 +192,6 @@ void ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status);
 dev_t bl_resolve_deviceid(struct nfs_server *server,
 		struct pnfs_block_volume *b, gfp_t gfp_mask);
 int __init bl_init_pipefs(void);
-void __exit bl_cleanup_pipefs(void);
+void bl_cleanup_pipefs(void);
 
 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */