xref: /linux/fs/nfs/blocklayout/blocklayout.h (revision d869da91)
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_SIZE >> SECTOR_SHIFT)
44 #define PAGE_CACHE_SECTOR_SHIFT (PAGE_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 struct pnfs_block_volume {
59 	enum pnfs_block_volume_type	type;
60 	union {
61 		struct {
62 			int		len;
63 			int		nr_sigs;
64 			struct {
65 				u64		offset;
66 				u32		sig_len;
67 				u8		sig[PNFS_BLOCK_UUID_LEN];
68 			} sigs[PNFS_BLOCK_MAX_UUIDS];
69 		} simple;
70 		struct {
71 			u64		start;
72 			u64		len;
73 			u32		volume;
74 		} slice;
75 		struct {
76 			u32		volumes_count;
77 			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
78 		} concat;
79 		struct {
80 			u64		chunk_size;
81 			u32		volumes_count;
82 			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
83 		} stripe;
84 		struct {
85 			enum scsi_code_set		code_set;
86 			enum scsi_designator_type	designator_type;
87 			int				designator_len;
88 			u8				designator[256];
89 			u64				pr_key;
90 		} scsi;
91 	};
92 };
93 
94 struct pnfs_block_dev_map {
95 	u64			start;
96 	u64			len;
97 	u64			disk_offset;
98 	struct block_device		*bdev;
99 };
100 
101 struct pnfs_block_dev {
102 	struct nfs4_deviceid_node	node;
103 
104 	u64				start;
105 	u64				len;
106 
107 	enum pnfs_block_volume_type	type;
108 	u32				nr_children;
109 	struct pnfs_block_dev		*children;
110 	u64				chunk_size;
111 
112 	struct file			*bdev_file;
113 	u64				disk_offset;
114 	unsigned long			flags;
115 
116 	u64				pr_key;
117 
118 	bool (*map)(struct pnfs_block_dev *dev, u64 offset,
119 			struct pnfs_block_dev_map *map);
120 };
121 
122 /* pnfs_block_dev flag bits */
123 enum {
124 	PNFS_BDEV_REGISTERED = 0,
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 pnfs_block_extent_state 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 struct pnfs_block_layout {
144 	struct pnfs_layout_hdr	bl_layout;
145 	struct rb_root		bl_ext_rw;
146 	struct rb_root		bl_ext_ro;
147 	spinlock_t		bl_ext_lock;   /* Protects list manipulation */
148 	bool			bl_scsi_layout;
149 	u64			bl_lwb;
150 };
151 
152 static inline struct pnfs_block_layout *
BLK_LO2EXT(struct pnfs_layout_hdr * lo)153 BLK_LO2EXT(struct pnfs_layout_hdr *lo)
154 {
155 	return container_of(lo, struct pnfs_block_layout, bl_layout);
156 }
157 
158 static inline struct pnfs_block_layout *
BLK_LSEG2EXT(struct pnfs_layout_segment * lseg)159 BLK_LSEG2EXT(struct pnfs_layout_segment *lseg)
160 {
161 	return BLK_LO2EXT(lseg->pls_layout);
162 }
163 
164 struct bl_pipe_msg {
165 	struct rpc_pipe_msg msg;
166 	wait_queue_head_t *bl_wq;
167 };
168 
169 struct bl_msg_hdr {
170 	u8  type;
171 	u16 totallen; /* length of entire message, including hdr itself */
172 };
173 
174 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
175 #define BL_DEVICE_MOUNT                0x1 /* Mount--create devices*/
176 #define BL_DEVICE_REQUEST_INIT         0x0 /* Start request */
177 #define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
178 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
179 
180 /* dev.c */
181 bool bl_register_dev(struct pnfs_block_dev *d);
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, u64 lwb);
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 bl_cleanup_pipefs(void);
203 
204 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */
205