xref: /openbmc/linux/fs/nfs/blocklayout/blocklayout.h (revision 0da85d1e)
1 /*
2  *  linux/fs/nfs/blocklayout/blocklayout.h
3  *
4  *  Module for the NFSv4.1 pNFS block layout driver.
5  *
6  *  Copyright (c) 2006 The Regents of the University of Michigan.
7  *  All rights reserved.
8  *
9  *  Andy Adamson <andros@citi.umich.edu>
10  *  Fred Isaman <iisaman@umich.edu>
11  *
12  * permission is granted to use, copy, create derivative works and
13  * redistribute this software and such derivative works for any purpose,
14  * so long as the name of the university of michigan is not used in
15  * any advertising or publicity pertaining to the use or distribution
16  * of this software without specific, written prior authorization.  if
17  * the above copyright notice or any other identification of the
18  * university of michigan is included in any copy of any portion of
19  * this software, then the disclaimer below must also be included.
20  *
21  * this software is provided as is, without representation from the
22  * university of michigan as to its fitness for any purpose, and without
23  * warranty by the university of michigan of any kind, either express
24  * or implied, including without limitation the implied warranties of
25  * merchantability and fitness for a particular purpose.  the regents
26  * of the university of michigan shall not be liable for any damages,
27  * including special, indirect, incidental, or consequential damages,
28  * with respect to any claim arising out or in connection with the use
29  * of the software, even if it has been or is hereafter advised of the
30  * possibility of such damages.
31  */
32 #ifndef FS_NFS_NFS4BLOCKLAYOUT_H
33 #define FS_NFS_NFS4BLOCKLAYOUT_H
34 
35 #include <linux/device-mapper.h>
36 #include <linux/nfs_fs.h>
37 #include <linux/sunrpc/rpc_pipe_fs.h>
38 
39 #include "../nfs4_fs.h"
40 #include "../pnfs.h"
41 #include "../netns.h"
42 
43 #define PAGE_CACHE_SECTORS (PAGE_CACHE_SIZE >> SECTOR_SHIFT)
44 #define PAGE_CACHE_SECTOR_SHIFT (PAGE_CACHE_SHIFT - SECTOR_SHIFT)
45 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
46 
47 struct pnfs_block_dev;
48 
49 enum pnfs_block_volume_type {
50 	PNFS_BLOCK_VOLUME_SIMPLE	= 0,
51 	PNFS_BLOCK_VOLUME_SLICE		= 1,
52 	PNFS_BLOCK_VOLUME_CONCAT	= 2,
53 	PNFS_BLOCK_VOLUME_STRIPE	= 3,
54 };
55 
56 #define PNFS_BLOCK_MAX_UUIDS	4
57 #define PNFS_BLOCK_MAX_DEVICES	64
58 
59 /*
60  * Random upper cap for the uuid length to avoid unbounded allocation.
61  * Not actually limited by the protocol.
62  */
63 #define PNFS_BLOCK_UUID_LEN	128
64 
65 
66 struct pnfs_block_volume {
67 	enum pnfs_block_volume_type	type;
68 	union {
69 		struct {
70 			int		len;
71 			int		nr_sigs;
72 			struct {
73 				u64		offset;
74 				u32		sig_len;
75 				u8		sig[PNFS_BLOCK_UUID_LEN];
76 			} sigs[PNFS_BLOCK_MAX_UUIDS];
77 		} simple;
78 		struct {
79 			u64		start;
80 			u64		len;
81 			u32		volume;
82 		} slice;
83 		struct {
84 			u32		volumes_count;
85 			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
86 		} concat;
87 		struct {
88 			u64		chunk_size;
89 			u32		volumes_count;
90 			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
91 		} stripe;
92 	};
93 };
94 
95 struct pnfs_block_dev_map {
96 	sector_t			start;
97 	sector_t			len;
98 
99 	sector_t			disk_offset;
100 	struct block_device		*bdev;
101 };
102 
103 struct pnfs_block_dev {
104 	struct nfs4_deviceid_node	node;
105 
106 	u64				start;
107 	u64				len;
108 
109 	u32				nr_children;
110 	struct pnfs_block_dev		*children;
111 	u64				chunk_size;
112 
113 	struct block_device		*bdev;
114 	u64				disk_offset;
115 
116 	bool (*map)(struct pnfs_block_dev *dev, u64 offset,
117 			struct pnfs_block_dev_map *map);
118 };
119 
120 enum exstate4 {
121 	PNFS_BLOCK_READWRITE_DATA	= 0,
122 	PNFS_BLOCK_READ_DATA		= 1,
123 	PNFS_BLOCK_INVALID_DATA		= 2, /* mapped, but data is invalid */
124 	PNFS_BLOCK_NONE_DATA		= 3  /* unmapped, it's a hole */
125 };
126 
127 /* sector_t fields are all in 512-byte sectors */
128 struct pnfs_block_extent {
129 	union {
130 		struct rb_node	be_node;
131 		struct list_head be_list;
132 	};
133 	struct nfs4_deviceid_node *be_device;
134 	sector_t	be_f_offset;	/* the starting offset in the file */
135 	sector_t	be_length;	/* the size of the extent */
136 	sector_t	be_v_offset;	/* the starting offset in the volume */
137 	enum exstate4	be_state;	/* the state of this extent */
138 #define EXTENT_WRITTEN		1
139 #define EXTENT_COMMITTING	2
140 	unsigned int	be_tag;
141 };
142 
143 /* on the wire size of the extent */
144 #define BL_EXTENT_SIZE	(7 * sizeof(__be32) + NFS4_DEVICEID4_SIZE)
145 
146 struct pnfs_block_layout {
147 	struct pnfs_layout_hdr	bl_layout;
148 	struct rb_root		bl_ext_rw;
149 	struct rb_root		bl_ext_ro;
150 	spinlock_t		bl_ext_lock;   /* Protects list manipulation */
151 };
152 
153 static inline struct pnfs_block_layout *
154 BLK_LO2EXT(struct pnfs_layout_hdr *lo)
155 {
156 	return container_of(lo, struct pnfs_block_layout, bl_layout);
157 }
158 
159 static inline struct pnfs_block_layout *
160 BLK_LSEG2EXT(struct pnfs_layout_segment *lseg)
161 {
162 	return BLK_LO2EXT(lseg->pls_layout);
163 }
164 
165 struct bl_pipe_msg {
166 	struct rpc_pipe_msg msg;
167 	wait_queue_head_t *bl_wq;
168 };
169 
170 struct bl_msg_hdr {
171 	u8  type;
172 	u16 totallen; /* length of entire message, including hdr itself */
173 };
174 
175 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
176 #define BL_DEVICE_MOUNT                0x1 /* Mount--create devices*/
177 #define BL_DEVICE_REQUEST_INIT         0x0 /* Start request */
178 #define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
179 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
180 
181 /* dev.c */
182 struct nfs4_deviceid_node *bl_alloc_deviceid_node(struct nfs_server *server,
183 		struct pnfs_device *pdev, gfp_t gfp_mask);
184 void bl_free_deviceid_node(struct nfs4_deviceid_node *d);
185 
186 /* extent_tree.c */
187 int ext_tree_insert(struct pnfs_block_layout *bl,
188 		struct pnfs_block_extent *new);
189 int ext_tree_remove(struct pnfs_block_layout *bl, bool rw, sector_t start,
190 		sector_t end);
191 int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
192 		sector_t len);
193 bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
194 		struct pnfs_block_extent *ret, bool rw);
195 int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg);
196 void ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status);
197 
198 /* rpc_pipefs.c */
199 dev_t bl_resolve_deviceid(struct nfs_server *server,
200 		struct pnfs_block_volume *b, gfp_t gfp_mask);
201 int __init bl_init_pipefs(void);
202 void __exit bl_cleanup_pipefs(void);
203 
204 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */
205