xref: /linux/fs/nfs/filelayout/filelayout.h (revision 2241f81c91f211b512bd2c3a26a4a74258d0e008)
1 /*
2  *  NFSv4 file layout driver data structures.
3  *
4  *  Copyright (c) 2002
5  *  The Regents of the University of Michigan
6  *  All Rights Reserved
7  *
8  *  Dean Hildebrand <dhildebz@umich.edu>
9  *
10  *  Permission is granted to use, copy, create derivative works, and
11  *  redistribute this software and such derivative works for any purpose,
12  *  so long as the name of the University of Michigan is not used in
13  *  any advertising or publicity pertaining to the use or distribution
14  *  of this software without specific, written prior authorization. If
15  *  the above copyright notice or any other identification of the
16  *  University of Michigan is included in any copy of any portion of
17  *  this software, then the disclaimer below must also be included.
18  *
19  *  This software is provided as is, without representation or warranty
20  *  of any kind either express or implied, including without limitation
21  *  the implied warranties of merchantability, fitness for a particular
22  *  purpose, or noninfringement.  The Regents of the University of
23  *  Michigan shall not be liable for any damages, including special,
24  *  indirect, incidental, or consequential damages, with respect to any
25  *  claim arising out of or in connection with the use of the software,
26  *  even if it has been or is hereafter advised of the possibility of
27  *  such damages.
28  */
29 
30 #ifndef FS_NFS_NFS4FILELAYOUT_H
31 #define FS_NFS_NFS4FILELAYOUT_H
32 
33 #include "../pnfs.h"
34 
35 /*
36  * Field testing shows we need to support up to 4096 stripe indices.
37  * We store each index as a u8 (u32 on the wire) to keep the memory footprint
38  * reasonable. This in turn means we support a maximum of 256
39  * RFC 5661 multipath_list4 structures.
40  */
41 #define NFS4_PNFS_MAX_STRIPE_CNT 4096
42 #define NFS4_PNFS_MAX_MULTI_CNT  256 /* 256 fit into a u8 stripe_index */
43 
44 enum stripetype4 {
45 	STRIPE_SPARSE = 1,
46 	STRIPE_DENSE = 2
47 };
48 
49 struct nfs4_file_layout_dsaddr {
50 	struct nfs4_deviceid_node	id_node;
51 	u32				stripe_count;
52 	u8				*stripe_indices;
53 	u32				ds_num;
54 	struct nfs4_pnfs_ds		*ds_list[] __counted_by(ds_num);
55 };
56 
57 struct nfs4_filelayout_segment {
58 	struct pnfs_layout_segment	generic_hdr;
59 	u32				stripe_type;
60 	u32				commit_through_mds;
61 	u32				stripe_unit;
62 	u32				first_stripe_index;
63 	u64				pattern_offset;
64 	struct nfs4_deviceid		deviceid;
65 	struct nfs4_file_layout_dsaddr	*dsaddr; /* Point to GETDEVINFO data */
66 	unsigned int			num_fh;
67 	struct nfs_fh			**fh_array;
68 };
69 
70 struct nfs4_filelayout {
71 	struct pnfs_layout_hdr generic_hdr;
72 	struct pnfs_ds_commit_info commit_info;
73 };
74 
75 static inline struct nfs4_filelayout *
76 FILELAYOUT_FROM_HDR(struct pnfs_layout_hdr *lo)
77 {
78 	return container_of(lo, struct nfs4_filelayout, generic_hdr);
79 }
80 
81 static inline struct nfs4_filelayout_segment *
82 FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
83 {
84 	return container_of(lseg,
85 			    struct nfs4_filelayout_segment,
86 			    generic_hdr);
87 }
88 
89 static inline struct nfs4_deviceid_node *
90 FILELAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg)
91 {
92 	return &FILELAYOUT_LSEG(lseg)->dsaddr->id_node;
93 }
94 
95 static inline bool
96 filelayout_test_devid_invalid(struct nfs4_deviceid_node *node)
97 {
98 	return test_bit(NFS_DEVICEID_INVALID, &node->flags);
99 }
100 
101 extern bool
102 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node);
103 
104 extern struct nfs_fh *
105 nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j);
106 
107 u32 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset);
108 u32 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j);
109 struct nfs4_pnfs_ds *nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg,
110 					u32 ds_idx);
111 
112 extern struct nfs4_file_layout_dsaddr *
113 nfs4_fl_alloc_deviceid_node(struct nfs_server *server,
114 	struct pnfs_device *pdev, gfp_t gfp_flags);
115 extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
116 extern void nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
117 
118 #endif /* FS_NFS_NFS4FILELAYOUT_H */
119