xref: /linux/fs/nfs/blocklayout/blocklayout.h (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
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 #define PNFS_BLOCK_MAX_UUIDS	4
50 #define PNFS_BLOCK_MAX_DEVICES	64
51 
52 /*
53  * Random upper cap for the uuid length to avoid unbounded allocation.
54  * Not actually limited by the protocol.
55  */
56 #define PNFS_BLOCK_UUID_LEN	128
57 
58 
59 struct pnfs_block_volume {
60 	enum pnfs_block_volume_type	type;
61 	union {
62 		struct {
63 			int		len;
64 			int		nr_sigs;
65 			struct {
66 				u64		offset;
67 				u32		sig_len;
68 				u8		sig[PNFS_BLOCK_UUID_LEN];
69 			} sigs[PNFS_BLOCK_MAX_UUIDS];
70 		} simple;
71 		struct {
72 			u64		start;
73 			u64		len;
74 			u32		volume;
75 		} slice;
76 		struct {
77 			u32		volumes_count;
78 			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
79 		} concat;
80 		struct {
81 			u64		chunk_size;
82 			u32		volumes_count;
83 			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
84 		} stripe;
85 	};
86 };
87 
88 struct pnfs_block_dev_map {
89 	sector_t			start;
90 	sector_t			len;
91 
92 	sector_t			disk_offset;
93 	struct block_device		*bdev;
94 };
95 
96 struct pnfs_block_dev {
97 	struct nfs4_deviceid_node	node;
98 
99 	u64				start;
100 	u64				len;
101 
102 	u32				nr_children;
103 	struct pnfs_block_dev		*children;
104 	u64				chunk_size;
105 
106 	struct block_device		*bdev;
107 	u64				disk_offset;
108 
109 	bool (*map)(struct pnfs_block_dev *dev, u64 offset,
110 			struct pnfs_block_dev_map *map);
111 };
112 
113 /* sector_t fields are all in 512-byte sectors */
114 struct pnfs_block_extent {
115 	union {
116 		struct rb_node	be_node;
117 		struct list_head be_list;
118 	};
119 	struct nfs4_deviceid_node *be_device;
120 	sector_t	be_f_offset;	/* the starting offset in the file */
121 	sector_t	be_length;	/* the size of the extent */
122 	sector_t	be_v_offset;	/* the starting offset in the volume */
123 	enum pnfs_block_extent_state be_state;	/* the state of this extent */
124 #define EXTENT_WRITTEN		1
125 #define EXTENT_COMMITTING	2
126 	unsigned int	be_tag;
127 };
128 
129 struct pnfs_block_layout {
130 	struct pnfs_layout_hdr	bl_layout;
131 	struct rb_root		bl_ext_rw;
132 	struct rb_root		bl_ext_ro;
133 	spinlock_t		bl_ext_lock;   /* Protects list manipulation */
134 };
135 
136 static inline struct pnfs_block_layout *
137 BLK_LO2EXT(struct pnfs_layout_hdr *lo)
138 {
139 	return container_of(lo, struct pnfs_block_layout, bl_layout);
140 }
141 
142 static inline struct pnfs_block_layout *
143 BLK_LSEG2EXT(struct pnfs_layout_segment *lseg)
144 {
145 	return BLK_LO2EXT(lseg->pls_layout);
146 }
147 
148 struct bl_pipe_msg {
149 	struct rpc_pipe_msg msg;
150 	wait_queue_head_t *bl_wq;
151 };
152 
153 struct bl_msg_hdr {
154 	u8  type;
155 	u16 totallen; /* length of entire message, including hdr itself */
156 };
157 
158 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
159 #define BL_DEVICE_MOUNT                0x1 /* Mount--create devices*/
160 #define BL_DEVICE_REQUEST_INIT         0x0 /* Start request */
161 #define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
162 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
163 
164 /* dev.c */
165 struct nfs4_deviceid_node *bl_alloc_deviceid_node(struct nfs_server *server,
166 		struct pnfs_device *pdev, gfp_t gfp_mask);
167 void bl_free_deviceid_node(struct nfs4_deviceid_node *d);
168 
169 /* extent_tree.c */
170 int ext_tree_insert(struct pnfs_block_layout *bl,
171 		struct pnfs_block_extent *new);
172 int ext_tree_remove(struct pnfs_block_layout *bl, bool rw, sector_t start,
173 		sector_t end);
174 int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
175 		sector_t len);
176 bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
177 		struct pnfs_block_extent *ret, bool rw);
178 int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg);
179 void ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status);
180 
181 /* rpc_pipefs.c */
182 dev_t bl_resolve_deviceid(struct nfs_server *server,
183 		struct pnfs_block_volume *b, gfp_t gfp_mask);
184 int __init bl_init_pipefs(void);
185 void __exit bl_cleanup_pipefs(void);
186 
187 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */
188