xref: /openbmc/linux/fs/nfsd/nfsfh.h (revision 4bce6fce)
1 /*
2  * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
3  *
4  * This file describes the layout of the file handles as passed
5  * over the wire.
6  */
7 #ifndef _LINUX_NFSD_NFSFH_H
8 #define _LINUX_NFSD_NFSFH_H
9 
10 #include <linux/sunrpc/svc.h>
11 #include <uapi/linux/nfsd/nfsfh.h>
12 
13 static inline __u32 ino_t_to_u32(ino_t ino)
14 {
15 	return (__u32) ino;
16 }
17 
18 static inline ino_t u32_to_ino_t(__u32 uino)
19 {
20 	return (ino_t) uino;
21 }
22 
23 /*
24  * This is the internal representation of an NFS handle used in knfsd.
25  * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
26  */
27 typedef struct svc_fh {
28 	struct knfsd_fh		fh_handle;	/* FH data */
29 	struct dentry *		fh_dentry;	/* validated dentry */
30 	struct svc_export *	fh_export;	/* export pointer */
31 	int			fh_maxsize;	/* max size for fh_handle */
32 
33 	unsigned char		fh_locked;	/* inode locked by us */
34 	unsigned char		fh_want_write;	/* remount protection taken */
35 
36 #ifdef CONFIG_NFSD_V3
37 	unsigned char		fh_post_saved;	/* post-op attrs saved */
38 	unsigned char		fh_pre_saved;	/* pre-op attrs saved */
39 
40 	/* Pre-op attributes saved during fh_lock */
41 	__u64			fh_pre_size;	/* size before operation */
42 	struct timespec		fh_pre_mtime;	/* mtime before oper */
43 	struct timespec		fh_pre_ctime;	/* ctime before oper */
44 	/*
45 	 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
46 	 *  to find out if it is valid.
47 	 */
48 	u64			fh_pre_change;
49 
50 	/* Post-op attributes saved in fh_unlock */
51 	struct kstat		fh_post_attr;	/* full attrs after operation */
52 	u64			fh_post_change; /* nfsv4 change; see above */
53 #endif /* CONFIG_NFSD_V3 */
54 
55 } svc_fh;
56 
57 enum nfsd_fsid {
58 	FSID_DEV = 0,
59 	FSID_NUM,
60 	FSID_MAJOR_MINOR,
61 	FSID_ENCODE_DEV,
62 	FSID_UUID4_INUM,
63 	FSID_UUID8,
64 	FSID_UUID16,
65 	FSID_UUID16_INUM,
66 };
67 
68 enum fsid_source {
69 	FSIDSOURCE_DEV,
70 	FSIDSOURCE_FSID,
71 	FSIDSOURCE_UUID,
72 };
73 extern enum fsid_source fsid_source(struct svc_fh *fhp);
74 
75 
76 /*
77  * This might look a little large to "inline" but in all calls except
78  * one, 'vers' is constant so moste of the function disappears.
79  *
80  * In some cases the values are considered to be host endian and in
81  * others, net endian. fsidv is always considered to be u32 as the
82  * callers don't know which it will be. So we must use __force to keep
83  * sparse from complaining. Since these values are opaque to the
84  * client, that shouldn't be a problem.
85  */
86 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
87 			   u32 fsid, unsigned char *uuid)
88 {
89 	u32 *up;
90 	switch(vers) {
91 	case FSID_DEV:
92 		fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
93 				 MINOR(dev));
94 		fsidv[1] = ino_t_to_u32(ino);
95 		break;
96 	case FSID_NUM:
97 		fsidv[0] = fsid;
98 		break;
99 	case FSID_MAJOR_MINOR:
100 		fsidv[0] = (__force __u32)htonl(MAJOR(dev));
101 		fsidv[1] = (__force __u32)htonl(MINOR(dev));
102 		fsidv[2] = ino_t_to_u32(ino);
103 		break;
104 
105 	case FSID_ENCODE_DEV:
106 		fsidv[0] = new_encode_dev(dev);
107 		fsidv[1] = ino_t_to_u32(ino);
108 		break;
109 
110 	case FSID_UUID4_INUM:
111 		/* 4 byte fsid and inode number */
112 		up = (u32*)uuid;
113 		fsidv[0] = ino_t_to_u32(ino);
114 		fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
115 		break;
116 
117 	case FSID_UUID8:
118 		/* 8 byte fsid  */
119 		up = (u32*)uuid;
120 		fsidv[0] = up[0] ^ up[2];
121 		fsidv[1] = up[1] ^ up[3];
122 		break;
123 
124 	case FSID_UUID16:
125 		/* 16 byte fsid - NFSv3+ only */
126 		memcpy(fsidv, uuid, 16);
127 		break;
128 
129 	case FSID_UUID16_INUM:
130 		/* 8 byte inode and 16 byte fsid */
131 		*(u64*)fsidv = (u64)ino;
132 		memcpy(fsidv+2, uuid, 16);
133 		break;
134 	default: BUG();
135 	}
136 }
137 
138 static inline int key_len(int type)
139 {
140 	switch(type) {
141 	case FSID_DEV:		return 8;
142 	case FSID_NUM: 		return 4;
143 	case FSID_MAJOR_MINOR:	return 12;
144 	case FSID_ENCODE_DEV:	return 8;
145 	case FSID_UUID4_INUM:	return 8;
146 	case FSID_UUID8:	return 8;
147 	case FSID_UUID16:	return 16;
148 	case FSID_UUID16_INUM:	return 24;
149 	default: return 0;
150 	}
151 }
152 
153 /*
154  * Shorthand for dprintk()'s
155  */
156 extern char * SVCFH_fmt(struct svc_fh *fhp);
157 
158 /*
159  * Function prototypes
160  */
161 __be32	fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
162 __be32	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
163 __be32	fh_update(struct svc_fh *);
164 void	fh_put(struct svc_fh *);
165 
166 static __inline__ struct svc_fh *
167 fh_copy(struct svc_fh *dst, struct svc_fh *src)
168 {
169 	WARN_ON(src->fh_dentry || src->fh_locked);
170 
171 	*dst = *src;
172 	return dst;
173 }
174 
175 static inline void
176 fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
177 {
178 	dst->fh_size = src->fh_size;
179 	memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
180 }
181 
182 static __inline__ struct svc_fh *
183 fh_init(struct svc_fh *fhp, int maxsize)
184 {
185 	memset(fhp, 0, sizeof(*fhp));
186 	fhp->fh_maxsize = maxsize;
187 	return fhp;
188 }
189 
190 static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
191 {
192 	if (fh1->fh_size != fh2->fh_size)
193 		return false;
194 	if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
195 		return false;
196 	return true;
197 }
198 
199 static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
200 {
201 	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
202 		return false;
203 	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
204 		return false;
205 	return true;
206 }
207 
208 #ifdef CONFIG_NFSD_V3
209 /*
210  * The wcc data stored in current_fh should be cleared
211  * between compound ops.
212  */
213 static inline void
214 fh_clear_wcc(struct svc_fh *fhp)
215 {
216 	fhp->fh_post_saved = 0;
217 	fhp->fh_pre_saved = 0;
218 }
219 
220 /*
221  * Fill in the pre_op attr for the wcc data
222  */
223 static inline void
224 fill_pre_wcc(struct svc_fh *fhp)
225 {
226 	struct inode    *inode;
227 
228 	inode = d_inode(fhp->fh_dentry);
229 	if (!fhp->fh_pre_saved) {
230 		fhp->fh_pre_mtime = inode->i_mtime;
231 		fhp->fh_pre_ctime = inode->i_ctime;
232 		fhp->fh_pre_size  = inode->i_size;
233 		fhp->fh_pre_change = inode->i_version;
234 		fhp->fh_pre_saved = 1;
235 	}
236 }
237 
238 extern void fill_post_wcc(struct svc_fh *);
239 #else
240 #define fh_clear_wcc(ignored)
241 #define fill_pre_wcc(ignored)
242 #define fill_post_wcc(notused)
243 #endif /* CONFIG_NFSD_V3 */
244 
245 
246 /*
247  * Lock a file handle/inode
248  * NOTE: both fh_lock and fh_unlock are done "by hand" in
249  * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
250  * so, any changes here should be reflected there.
251  */
252 
253 static inline void
254 fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
255 {
256 	struct dentry	*dentry = fhp->fh_dentry;
257 	struct inode	*inode;
258 
259 	BUG_ON(!dentry);
260 
261 	if (fhp->fh_locked) {
262 		printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
263 			dentry);
264 		return;
265 	}
266 
267 	inode = d_inode(dentry);
268 	mutex_lock_nested(&inode->i_mutex, subclass);
269 	fill_pre_wcc(fhp);
270 	fhp->fh_locked = 1;
271 }
272 
273 static inline void
274 fh_lock(struct svc_fh *fhp)
275 {
276 	fh_lock_nested(fhp, I_MUTEX_NORMAL);
277 }
278 
279 /*
280  * Unlock a file handle/inode
281  */
282 static inline void
283 fh_unlock(struct svc_fh *fhp)
284 {
285 	if (fhp->fh_locked) {
286 		fill_post_wcc(fhp);
287 		mutex_unlock(&d_inode(fhp->fh_dentry)->i_mutex);
288 		fhp->fh_locked = 0;
289 	}
290 }
291 
292 #endif /* _LINUX_NFSD_NFSFH_H */
293