xref: /openbmc/linux/fs/nfsd/nfsfh.h (revision d2999e1b)
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 /* This might look a little large to "inline" but in all calls except
77  * one, 'vers' is constant so moste of the function disappears.
78  */
79 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
80 			   u32 fsid, unsigned char *uuid)
81 {
82 	u32 *up;
83 	switch(vers) {
84 	case FSID_DEV:
85 		fsidv[0] = htonl((MAJOR(dev)<<16) |
86 				 MINOR(dev));
87 		fsidv[1] = ino_t_to_u32(ino);
88 		break;
89 	case FSID_NUM:
90 		fsidv[0] = fsid;
91 		break;
92 	case FSID_MAJOR_MINOR:
93 		fsidv[0] = htonl(MAJOR(dev));
94 		fsidv[1] = htonl(MINOR(dev));
95 		fsidv[2] = ino_t_to_u32(ino);
96 		break;
97 
98 	case FSID_ENCODE_DEV:
99 		fsidv[0] = new_encode_dev(dev);
100 		fsidv[1] = ino_t_to_u32(ino);
101 		break;
102 
103 	case FSID_UUID4_INUM:
104 		/* 4 byte fsid and inode number */
105 		up = (u32*)uuid;
106 		fsidv[0] = ino_t_to_u32(ino);
107 		fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
108 		break;
109 
110 	case FSID_UUID8:
111 		/* 8 byte fsid  */
112 		up = (u32*)uuid;
113 		fsidv[0] = up[0] ^ up[2];
114 		fsidv[1] = up[1] ^ up[3];
115 		break;
116 
117 	case FSID_UUID16:
118 		/* 16 byte fsid - NFSv3+ only */
119 		memcpy(fsidv, uuid, 16);
120 		break;
121 
122 	case FSID_UUID16_INUM:
123 		/* 8 byte inode and 16 byte fsid */
124 		*(u64*)fsidv = (u64)ino;
125 		memcpy(fsidv+2, uuid, 16);
126 		break;
127 	default: BUG();
128 	}
129 }
130 
131 static inline int key_len(int type)
132 {
133 	switch(type) {
134 	case FSID_DEV:		return 8;
135 	case FSID_NUM: 		return 4;
136 	case FSID_MAJOR_MINOR:	return 12;
137 	case FSID_ENCODE_DEV:	return 8;
138 	case FSID_UUID4_INUM:	return 8;
139 	case FSID_UUID8:	return 8;
140 	case FSID_UUID16:	return 16;
141 	case FSID_UUID16_INUM:	return 24;
142 	default: return 0;
143 	}
144 }
145 
146 /*
147  * Shorthand for dprintk()'s
148  */
149 extern char * SVCFH_fmt(struct svc_fh *fhp);
150 
151 /*
152  * Function prototypes
153  */
154 __be32	fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
155 __be32	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
156 __be32	fh_update(struct svc_fh *);
157 void	fh_put(struct svc_fh *);
158 
159 static __inline__ struct svc_fh *
160 fh_copy(struct svc_fh *dst, struct svc_fh *src)
161 {
162 	WARN_ON(src->fh_dentry || src->fh_locked);
163 
164 	*dst = *src;
165 	return dst;
166 }
167 
168 static inline void
169 fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
170 {
171 	dst->fh_size = src->fh_size;
172 	memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
173 }
174 
175 static __inline__ struct svc_fh *
176 fh_init(struct svc_fh *fhp, int maxsize)
177 {
178 	memset(fhp, 0, sizeof(*fhp));
179 	fhp->fh_maxsize = maxsize;
180 	return fhp;
181 }
182 
183 #ifdef CONFIG_NFSD_V3
184 /*
185  * The wcc data stored in current_fh should be cleared
186  * between compound ops.
187  */
188 static inline void
189 fh_clear_wcc(struct svc_fh *fhp)
190 {
191 	fhp->fh_post_saved = 0;
192 	fhp->fh_pre_saved = 0;
193 }
194 
195 /*
196  * Fill in the pre_op attr for the wcc data
197  */
198 static inline void
199 fill_pre_wcc(struct svc_fh *fhp)
200 {
201 	struct inode    *inode;
202 
203 	inode = fhp->fh_dentry->d_inode;
204 	if (!fhp->fh_pre_saved) {
205 		fhp->fh_pre_mtime = inode->i_mtime;
206 		fhp->fh_pre_ctime = inode->i_ctime;
207 		fhp->fh_pre_size  = inode->i_size;
208 		fhp->fh_pre_change = inode->i_version;
209 		fhp->fh_pre_saved = 1;
210 	}
211 }
212 
213 extern void fill_post_wcc(struct svc_fh *);
214 #else
215 #define fh_clear_wcc(ignored)
216 #define fill_pre_wcc(ignored)
217 #define fill_post_wcc(notused)
218 #endif /* CONFIG_NFSD_V3 */
219 
220 
221 /*
222  * Lock a file handle/inode
223  * NOTE: both fh_lock and fh_unlock are done "by hand" in
224  * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
225  * so, any changes here should be reflected there.
226  */
227 
228 static inline void
229 fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
230 {
231 	struct dentry	*dentry = fhp->fh_dentry;
232 	struct inode	*inode;
233 
234 	BUG_ON(!dentry);
235 
236 	if (fhp->fh_locked) {
237 		printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
238 			dentry);
239 		return;
240 	}
241 
242 	inode = dentry->d_inode;
243 	mutex_lock_nested(&inode->i_mutex, subclass);
244 	fill_pre_wcc(fhp);
245 	fhp->fh_locked = 1;
246 }
247 
248 static inline void
249 fh_lock(struct svc_fh *fhp)
250 {
251 	fh_lock_nested(fhp, I_MUTEX_NORMAL);
252 }
253 
254 /*
255  * Unlock a file handle/inode
256  */
257 static inline void
258 fh_unlock(struct svc_fh *fhp)
259 {
260 	if (fhp->fh_locked) {
261 		fill_post_wcc(fhp);
262 		mutex_unlock(&fhp->fh_dentry->d_inode->i_mutex);
263 		fhp->fh_locked = 0;
264 	}
265 }
266 
267 #endif /* _LINUX_NFSD_NFSFH_H */
268