xref: /openbmc/linux/fs/nfs/pnfs.h (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  *  pNFS client 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_PNFS_H
31 #define FS_NFS_PNFS_H
32 
33 enum {
34 	NFS_LSEG_VALID = 0,	/* cleared when lseg is recalled/returned */
35 	NFS_LSEG_ROC,		/* roc bit received from server */
36 };
37 
38 struct pnfs_layout_segment {
39 	struct list_head pls_list;
40 	struct pnfs_layout_range pls_range;
41 	atomic_t pls_refcount;
42 	unsigned long pls_flags;
43 	struct pnfs_layout_hdr *pls_layout;
44 };
45 
46 #ifdef CONFIG_NFS_V4_1
47 
48 #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
49 
50 enum {
51 	NFS_LAYOUT_RO_FAILED = 0,	/* get ro layout failed stop trying */
52 	NFS_LAYOUT_RW_FAILED,		/* get rw layout failed stop trying */
53 	NFS_LAYOUT_BULK_RECALL,		/* bulk recall affecting layout */
54 	NFS_LAYOUT_ROC,			/* some lseg had roc bit set */
55 	NFS_LAYOUT_DESTROYED,		/* no new use of layout allowed */
56 };
57 
58 /* Per-layout driver specific registration structure */
59 struct pnfs_layoutdriver_type {
60 	struct list_head pnfs_tblid;
61 	const u32 id;
62 	const char *name;
63 	struct module *owner;
64 	int (*set_layoutdriver) (struct nfs_server *);
65 	int (*clear_layoutdriver) (struct nfs_server *);
66 	struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);
67 	void (*free_lseg) (struct pnfs_layout_segment *lseg);
68 };
69 
70 struct pnfs_layout_hdr {
71 	atomic_t		plh_refcount;
72 	struct list_head	plh_layouts;   /* other client layouts */
73 	struct list_head	plh_bulk_recall; /* clnt list of bulk recalls */
74 	struct list_head	plh_segs;      /* layout segments list */
75 	nfs4_stateid		plh_stateid;
76 	atomic_t		plh_outstanding; /* number of RPCs out */
77 	unsigned long		plh_block_lgets; /* block LAYOUTGET if >0 */
78 	u32			plh_barrier; /* ignore lower seqids */
79 	unsigned long		plh_flags;
80 	struct inode		*plh_inode;
81 };
82 
83 struct pnfs_device {
84 	struct nfs4_deviceid dev_id;
85 	unsigned int  layout_type;
86 	unsigned int  mincount;
87 	struct page **pages;
88 	void          *area;
89 	unsigned int  pgbase;
90 	unsigned int  pglen;
91 };
92 
93 /*
94  * Device ID RCU cache. A device ID is unique per client ID and layout type.
95  */
96 #define NFS4_DEVICE_ID_HASH_BITS	5
97 #define NFS4_DEVICE_ID_HASH_SIZE	(1 << NFS4_DEVICE_ID_HASH_BITS)
98 #define NFS4_DEVICE_ID_HASH_MASK	(NFS4_DEVICE_ID_HASH_SIZE - 1)
99 
100 static inline u32
101 nfs4_deviceid_hash(struct nfs4_deviceid *id)
102 {
103 	unsigned char *cptr = (unsigned char *)id->data;
104 	unsigned int nbytes = NFS4_DEVICEID4_SIZE;
105 	u32 x = 0;
106 
107 	while (nbytes--) {
108 		x *= 37;
109 		x += *cptr++;
110 	}
111 	return x & NFS4_DEVICE_ID_HASH_MASK;
112 }
113 
114 struct pnfs_deviceid_node {
115 	struct hlist_node	de_node;
116 	struct nfs4_deviceid	de_id;
117 	atomic_t		de_ref;
118 };
119 
120 struct pnfs_deviceid_cache {
121 	spinlock_t		dc_lock;
122 	atomic_t		dc_ref;
123 	void			(*dc_free_callback)(struct pnfs_deviceid_node *);
124 	struct hlist_head	dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
125 };
126 
127 extern int pnfs_alloc_init_deviceid_cache(struct nfs_client *,
128 			void (*free_callback)(struct pnfs_deviceid_node *));
129 extern void pnfs_put_deviceid_cache(struct nfs_client *);
130 extern struct pnfs_deviceid_node *pnfs_find_get_deviceid(
131 				struct pnfs_deviceid_cache *,
132 				struct nfs4_deviceid *);
133 extern struct pnfs_deviceid_node *pnfs_add_deviceid(
134 				struct pnfs_deviceid_cache *,
135 				struct pnfs_deviceid_node *);
136 extern void pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
137 			      struct pnfs_deviceid_node *devid);
138 
139 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
140 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
141 
142 /* nfs4proc.c */
143 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
144 				   struct pnfs_device *dev);
145 extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
146 
147 /* pnfs.c */
148 void get_layout_hdr(struct pnfs_layout_hdr *lo);
149 struct pnfs_layout_segment *
150 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
151 		   enum pnfs_iomode access_type);
152 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
153 void unset_pnfs_layoutdriver(struct nfs_server *);
154 int pnfs_layout_process(struct nfs4_layoutget *lgp);
155 void pnfs_free_lseg_list(struct list_head *tmp_list);
156 void pnfs_destroy_layout(struct nfs_inode *);
157 void pnfs_destroy_all_layouts(struct nfs_client *);
158 void put_layout_hdr(struct pnfs_layout_hdr *lo);
159 void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
160 			     const nfs4_stateid *new,
161 			     bool update_barrier);
162 int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
163 				  struct pnfs_layout_hdr *lo,
164 				  struct nfs4_state *open_state);
165 int mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
166 				struct list_head *tmp_list,
167 				u32 iomode);
168 bool pnfs_roc(struct inode *ino);
169 void pnfs_roc_release(struct inode *ino);
170 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
171 bool pnfs_roc_drain(struct inode *ino, u32 *barrier);
172 
173 
174 static inline int lo_fail_bit(u32 iomode)
175 {
176 	return iomode == IOMODE_RW ?
177 			 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
178 }
179 
180 /* Return true if a layout driver is being used for this mountpoint */
181 static inline int pnfs_enabled_sb(struct nfs_server *nfss)
182 {
183 	return nfss->pnfs_curr_ld != NULL;
184 }
185 
186 #else  /* CONFIG_NFS_V4_1 */
187 
188 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
189 {
190 }
191 
192 static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
193 {
194 }
195 
196 static inline struct pnfs_layout_segment *
197 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
198 		   enum pnfs_iomode access_type)
199 {
200 	return NULL;
201 }
202 
203 static inline bool
204 pnfs_roc(struct inode *ino)
205 {
206 	return false;
207 }
208 
209 static inline void
210 pnfs_roc_release(struct inode *ino)
211 {
212 }
213 
214 static inline void
215 pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
216 {
217 }
218 
219 static inline bool
220 pnfs_roc_drain(struct inode *ino, u32 *barrier)
221 {
222 	return false;
223 }
224 
225 static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
226 {
227 }
228 
229 static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
230 {
231 }
232 
233 #endif /* CONFIG_NFS_V4_1 */
234 
235 #endif /* FS_NFS_PNFS_H */
236