xref: /linux/fs/nfsd/nfsfh.h (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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/crc32.h>
11 #include <linux/sunrpc/svc.h>
12 #include <uapi/linux/nfsd/nfsfh.h>
13 
14 static inline __u32 ino_t_to_u32(ino_t ino)
15 {
16 	return (__u32) ino;
17 }
18 
19 static inline ino_t u32_to_ino_t(__u32 uino)
20 {
21 	return (ino_t) uino;
22 }
23 
24 /*
25  * This is the internal representation of an NFS handle used in knfsd.
26  * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
27  */
28 typedef struct svc_fh {
29 	struct knfsd_fh		fh_handle;	/* FH data */
30 	int			fh_maxsize;	/* max size for fh_handle */
31 	struct dentry *		fh_dentry;	/* validated dentry */
32 	struct svc_export *	fh_export;	/* export pointer */
33 
34 	bool			fh_locked;	/* inode locked by us */
35 	bool			fh_want_write;	/* remount protection taken */
36 
37 #ifdef CONFIG_NFSD_V3
38 	bool			fh_post_saved;	/* post-op attrs saved */
39 	bool			fh_pre_saved;	/* pre-op attrs saved */
40 
41 	/* Pre-op attributes saved during fh_lock */
42 	__u64			fh_pre_size;	/* size before operation */
43 	struct timespec		fh_pre_mtime;	/* mtime before oper */
44 	struct timespec		fh_pre_ctime;	/* ctime before oper */
45 	/*
46 	 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
47 	 *  to find out if it is valid.
48 	 */
49 	u64			fh_pre_change;
50 
51 	/* Post-op attributes saved in fh_unlock */
52 	struct kstat		fh_post_attr;	/* full attrs after operation */
53 	u64			fh_post_change; /* nfsv4 change; see above */
54 #endif /* CONFIG_NFSD_V3 */
55 
56 } svc_fh;
57 
58 enum nfsd_fsid {
59 	FSID_DEV = 0,
60 	FSID_NUM,
61 	FSID_MAJOR_MINOR,
62 	FSID_ENCODE_DEV,
63 	FSID_UUID4_INUM,
64 	FSID_UUID8,
65 	FSID_UUID16,
66 	FSID_UUID16_INUM,
67 };
68 
69 enum fsid_source {
70 	FSIDSOURCE_DEV,
71 	FSIDSOURCE_FSID,
72 	FSIDSOURCE_UUID,
73 };
74 extern enum fsid_source fsid_source(struct svc_fh *fhp);
75 
76 
77 /*
78  * This might look a little large to "inline" but in all calls except
79  * one, 'vers' is constant so moste of the function disappears.
80  *
81  * In some cases the values are considered to be host endian and in
82  * others, net endian. fsidv is always considered to be u32 as the
83  * callers don't know which it will be. So we must use __force to keep
84  * sparse from complaining. Since these values are opaque to the
85  * client, that shouldn't be a problem.
86  */
87 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
88 			   u32 fsid, unsigned char *uuid)
89 {
90 	u32 *up;
91 	switch(vers) {
92 	case FSID_DEV:
93 		fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
94 				 MINOR(dev));
95 		fsidv[1] = ino_t_to_u32(ino);
96 		break;
97 	case FSID_NUM:
98 		fsidv[0] = fsid;
99 		break;
100 	case FSID_MAJOR_MINOR:
101 		fsidv[0] = (__force __u32)htonl(MAJOR(dev));
102 		fsidv[1] = (__force __u32)htonl(MINOR(dev));
103 		fsidv[2] = ino_t_to_u32(ino);
104 		break;
105 
106 	case FSID_ENCODE_DEV:
107 		fsidv[0] = new_encode_dev(dev);
108 		fsidv[1] = ino_t_to_u32(ino);
109 		break;
110 
111 	case FSID_UUID4_INUM:
112 		/* 4 byte fsid and inode number */
113 		up = (u32*)uuid;
114 		fsidv[0] = ino_t_to_u32(ino);
115 		fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
116 		break;
117 
118 	case FSID_UUID8:
119 		/* 8 byte fsid  */
120 		up = (u32*)uuid;
121 		fsidv[0] = up[0] ^ up[2];
122 		fsidv[1] = up[1] ^ up[3];
123 		break;
124 
125 	case FSID_UUID16:
126 		/* 16 byte fsid - NFSv3+ only */
127 		memcpy(fsidv, uuid, 16);
128 		break;
129 
130 	case FSID_UUID16_INUM:
131 		/* 8 byte inode and 16 byte fsid */
132 		*(u64*)fsidv = (u64)ino;
133 		memcpy(fsidv+2, uuid, 16);
134 		break;
135 	default: BUG();
136 	}
137 }
138 
139 static inline int key_len(int type)
140 {
141 	switch(type) {
142 	case FSID_DEV:		return 8;
143 	case FSID_NUM: 		return 4;
144 	case FSID_MAJOR_MINOR:	return 12;
145 	case FSID_ENCODE_DEV:	return 8;
146 	case FSID_UUID4_INUM:	return 8;
147 	case FSID_UUID8:	return 8;
148 	case FSID_UUID16:	return 16;
149 	case FSID_UUID16_INUM:	return 24;
150 	default: return 0;
151 	}
152 }
153 
154 /*
155  * Shorthand for dprintk()'s
156  */
157 extern char * SVCFH_fmt(struct svc_fh *fhp);
158 
159 /*
160  * Function prototypes
161  */
162 __be32	fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
163 __be32	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
164 __be32	fh_update(struct svc_fh *);
165 void	fh_put(struct svc_fh *);
166 
167 static __inline__ struct svc_fh *
168 fh_copy(struct svc_fh *dst, struct svc_fh *src)
169 {
170 	WARN_ON(src->fh_dentry || src->fh_locked);
171 
172 	*dst = *src;
173 	return dst;
174 }
175 
176 static inline void
177 fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
178 {
179 	dst->fh_size = src->fh_size;
180 	memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
181 }
182 
183 static __inline__ struct svc_fh *
184 fh_init(struct svc_fh *fhp, int maxsize)
185 {
186 	memset(fhp, 0, sizeof(*fhp));
187 	fhp->fh_maxsize = maxsize;
188 	return fhp;
189 }
190 
191 static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
192 {
193 	if (fh1->fh_size != fh2->fh_size)
194 		return false;
195 	if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
196 		return false;
197 	return true;
198 }
199 
200 static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
201 {
202 	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
203 		return false;
204 	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
205 		return false;
206 	return true;
207 }
208 
209 #ifdef CONFIG_CRC32
210 /**
211  * knfsd_fh_hash - calculate the crc32 hash for the filehandle
212  * @fh - pointer to filehandle
213  *
214  * returns a crc32 hash for the filehandle that is compatible with
215  * the one displayed by "wireshark".
216  */
217 
218 static inline u32
219 knfsd_fh_hash(struct knfsd_fh *fh)
220 {
221 	return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size);
222 }
223 #else
224 static inline u32
225 knfsd_fh_hash(struct knfsd_fh *fh)
226 {
227 	return 0;
228 }
229 #endif
230 
231 #ifdef CONFIG_NFSD_V3
232 /*
233  * The wcc data stored in current_fh should be cleared
234  * between compound ops.
235  */
236 static inline void
237 fh_clear_wcc(struct svc_fh *fhp)
238 {
239 	fhp->fh_post_saved = false;
240 	fhp->fh_pre_saved = false;
241 }
242 
243 /*
244  * Fill in the pre_op attr for the wcc data
245  */
246 static inline void
247 fill_pre_wcc(struct svc_fh *fhp)
248 {
249 	struct inode    *inode;
250 
251 	inode = d_inode(fhp->fh_dentry);
252 	if (!fhp->fh_pre_saved) {
253 		fhp->fh_pre_mtime = inode->i_mtime;
254 		fhp->fh_pre_ctime = inode->i_ctime;
255 		fhp->fh_pre_size  = inode->i_size;
256 		fhp->fh_pre_change = inode->i_version;
257 		fhp->fh_pre_saved = true;
258 	}
259 }
260 
261 extern void fill_post_wcc(struct svc_fh *);
262 #else
263 #define fh_clear_wcc(ignored)
264 #define fill_pre_wcc(ignored)
265 #define fill_post_wcc(notused)
266 #endif /* CONFIG_NFSD_V3 */
267 
268 
269 /*
270  * Lock a file handle/inode
271  * NOTE: both fh_lock and fh_unlock are done "by hand" in
272  * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
273  * so, any changes here should be reflected there.
274  */
275 
276 static inline void
277 fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
278 {
279 	struct dentry	*dentry = fhp->fh_dentry;
280 	struct inode	*inode;
281 
282 	BUG_ON(!dentry);
283 
284 	if (fhp->fh_locked) {
285 		printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
286 			dentry);
287 		return;
288 	}
289 
290 	inode = d_inode(dentry);
291 	inode_lock_nested(inode, subclass);
292 	fill_pre_wcc(fhp);
293 	fhp->fh_locked = true;
294 }
295 
296 static inline void
297 fh_lock(struct svc_fh *fhp)
298 {
299 	fh_lock_nested(fhp, I_MUTEX_NORMAL);
300 }
301 
302 /*
303  * Unlock a file handle/inode
304  */
305 static inline void
306 fh_unlock(struct svc_fh *fhp)
307 {
308 	if (fhp->fh_locked) {
309 		fill_post_wcc(fhp);
310 		inode_unlock(d_inode(fhp->fh_dentry));
311 		fhp->fh_locked = false;
312 	}
313 }
314 
315 #endif /* _LINUX_NFSD_NFSFH_H */
316