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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
a5694255 CH |
2 | #ifndef LINUX_EXPORTFS_H |
3 | #define LINUX_EXPORTFS_H 1 | |
4 | ||
5 | #include <linux/types.h> | |
6 | ||
7 | struct dentry; | |
7fbc1067 | 8 | struct iattr; |
2596110a | 9 | struct inode; |
199a31c6 | 10 | struct iomap; |
a5694255 | 11 | struct super_block; |
d37065cd | 12 | struct vfsmount; |
a5694255 | 13 | |
990d6c2d AK |
14 | /* limit the handle size to NFSv4 handle size now */ |
15 | #define MAX_HANDLE_SZ 128 | |
16 | ||
6e91ea2b CH |
17 | /* |
18 | * The fileid_type identifies how the file within the filesystem is encoded. | |
19 | * In theory this is freely set and parsed by the filesystem, but we try to | |
20 | * stick to conventions so we can share some generic code and don't confuse | |
21 | * sniffers like ethereal/wireshark. | |
22 | * | |
23 | * The filesystem must not use the value '0' or '0xff'. | |
24 | */ | |
25 | enum fid_type { | |
26 | /* | |
27 | * The root, or export point, of the filesystem. | |
28 | * (Never actually passed down to the filesystem. | |
29 | */ | |
30 | FILEID_ROOT = 0, | |
31 | ||
32 | /* | |
33 | * 32bit inode number, 32 bit generation number. | |
34 | */ | |
35 | FILEID_INO32_GEN = 1, | |
36 | ||
37 | /* | |
38 | * 32bit inode number, 32 bit generation number, | |
39 | * 32 bit parent directory inode number. | |
40 | */ | |
41 | FILEID_INO32_GEN_PARENT = 2, | |
221e583a | 42 | |
e4464fac DW |
43 | /* |
44 | * 64 bit object ID, 64 bit root object ID, | |
45 | * 32 bit generation number. | |
46 | */ | |
47 | FILEID_BTRFS_WITHOUT_PARENT = 0x4d, | |
48 | ||
49 | /* | |
50 | * 64 bit object ID, 64 bit root object ID, | |
51 | * 32 bit generation number, | |
52 | * 64 bit parent object ID, 32 bit parent generation. | |
53 | */ | |
54 | FILEID_BTRFS_WITH_PARENT = 0x4e, | |
55 | ||
56 | /* | |
57 | * 64 bit object ID, 64 bit root object ID, | |
58 | * 32 bit generation number, | |
59 | * 64 bit parent object ID, 32 bit parent generation, | |
60 | * 64 bit parent root object ID. | |
61 | */ | |
62 | FILEID_BTRFS_WITH_PARENT_ROOT = 0x4f, | |
63 | ||
221e583a RR |
64 | /* |
65 | * 32 bit block number, 16 bit partition reference, | |
66 | * 16 bit unused, 32 bit generation number. | |
67 | */ | |
68 | FILEID_UDF_WITHOUT_PARENT = 0x51, | |
69 | ||
70 | /* | |
71 | * 32 bit block number, 16 bit partition reference, | |
72 | * 16 bit unused, 32 bit generation number, | |
73 | * 32 bit parent block number, 32 bit parent generation number | |
74 | */ | |
75 | FILEID_UDF_WITH_PARENT = 0x52, | |
8e656fd5 RK |
76 | |
77 | /* | |
78 | * 64 bit checkpoint number, 64 bit inode number, | |
79 | * 32 bit generation number. | |
80 | */ | |
81 | FILEID_NILFS_WITHOUT_PARENT = 0x61, | |
82 | ||
83 | /* | |
84 | * 64 bit checkpoint number, 64 bit inode number, | |
85 | * 32 bit generation number, 32 bit parent generation. | |
86 | * 64 bit parent inode number. | |
87 | */ | |
88 | FILEID_NILFS_WITH_PARENT = 0x62, | |
216b6cbd | 89 | |
ea3983ac NJ |
90 | /* |
91 | * 32 bit generation number, 40 bit i_pos. | |
92 | */ | |
93 | FILEID_FAT_WITHOUT_PARENT = 0x71, | |
94 | ||
95 | /* | |
96 | * 32 bit generation number, 40 bit i_pos, | |
97 | * 32 bit parent generation number, 40 bit parent i_pos | |
98 | */ | |
99 | FILEID_FAT_WITH_PARENT = 0x72, | |
100 | ||
41d1ddd2 AG |
101 | /* |
102 | * 64 bit inode number, 32 bit generation number. | |
103 | */ | |
104 | FILEID_INO64_GEN = 0x81, | |
105 | ||
106 | /* | |
107 | * 64 bit inode number, 32 bit generation number, | |
108 | * 64 bit parent inode number, 32 bit parent generation. | |
109 | */ | |
110 | FILEID_INO64_GEN_PARENT = 0x82, | |
111 | ||
cb776592 DE |
112 | /* |
113 | * 128 bit child FID (struct lu_fid) | |
114 | * 128 bit parent FID (struct lu_fid) | |
115 | */ | |
116 | FILEID_LUSTRE = 0x97, | |
117 | ||
b827ac41 KO |
118 | /* |
119 | * 64 bit inode number, 32 bit subvolume, 32 bit generation number: | |
120 | */ | |
121 | FILEID_BCACHEFS_WITHOUT_PARENT = 0xb1, | |
122 | FILEID_BCACHEFS_WITH_PARENT = 0xb2, | |
123 | ||
33c5ac91 TH |
124 | /* |
125 | * 64 bit unique kernfs id | |
126 | */ | |
127 | FILEID_KERNFS = 0xfe, | |
128 | ||
216b6cbd NJ |
129 | /* |
130 | * Filesystems must not use 0xff file ID. | |
131 | */ | |
132 | FILEID_INVALID = 0xff, | |
6e91ea2b CH |
133 | }; |
134 | ||
135 | struct fid { | |
136 | union { | |
137 | struct { | |
138 | u32 ino; | |
139 | u32 gen; | |
140 | u32 parent_ino; | |
141 | u32 parent_gen; | |
142 | } i32; | |
64343119 AG |
143 | struct { |
144 | u64 ino; | |
145 | u32 gen; | |
146 | } __packed i64; | |
147 | struct { | |
221e583a RR |
148 | u32 block; |
149 | u16 partref; | |
150 | u16 parent_partref; | |
151 | u32 generation; | |
152 | u32 parent_block; | |
153 | u32 parent_generation; | |
154 | } udf; | |
37e2b570 | 155 | DECLARE_FLEX_ARRAY(__u32, raw); |
6e91ea2b CH |
156 | }; |
157 | }; | |
a5694255 | 158 | |
b5287827 | 159 | #define EXPORT_FH_CONNECTABLE 0x1 /* Encode file handle with parent */ |
304e9c83 | 160 | #define EXPORT_FH_FID 0x2 /* File handle may be non-decodeable */ |
b5287827 | 161 | |
a5694255 CH |
162 | /** |
163 | * struct export_operations - for nfsd to communicate with file systems | |
a5694255 | 164 | * @encode_fh: encode a file handle fragment from a dentry |
9b89ca7a MD |
165 | * @fh_to_dentry: find the implied object and get a dentry for it |
166 | * @fh_to_parent: find the implied object's parent and get a dentry for it | |
a5694255 CH |
167 | * @get_name: find the name for a given inode in a given directory |
168 | * @get_parent: find the parent of a given directory | |
f501912a | 169 | * @commit_metadata: commit metadata changes to stable storage |
a5694255 | 170 | * |
ec23eb54 | 171 | * See Documentation/filesystems/nfs/exporting.rst for details on how to use |
e38f9817 | 172 | * this interface correctly. |
a5694255 | 173 | * |
a5694255 CH |
174 | * encode_fh: |
175 | * @encode_fh should store in the file handle fragment @fh (using at most | |
176 | * @max_len bytes) information that can be used by @decode_fh to recover the | |
b5287827 | 177 | * file referred to by the &struct dentry @de. If @flag has CONNECTABLE bit |
a5694255 CH |
178 | * set, the encode_fh() should store sufficient information so that a good |
179 | * attempt can be made to find not only the file but also it's place in the | |
180 | * filesystem. This typically means storing a reference to de->d_parent in | |
5fe0c237 AK |
181 | * the filehandle fragment. encode_fh() should return the fileid_type on |
182 | * success and on error returns 255 (if the space needed to encode fh is | |
183 | * greater than @max_len*4 bytes). On error @max_len contains the minimum | |
184 | * size(in 4 byte unit) needed to encode the file handle. | |
a5694255 | 185 | * |
2596110a CH |
186 | * fh_to_dentry: |
187 | * @fh_to_dentry is given a &struct super_block (@sb) and a file handle | |
188 | * fragment (@fh, @fh_len). It should return a &struct dentry which refers | |
189 | * to the same file that the file handle fragment refers to. If it cannot, | |
09bb8bff N |
190 | * it should return a %NULL pointer if the file cannot be found, or an |
191 | * %ERR_PTR error code of %ENOMEM if a memory allocation failure occurred. | |
192 | * Any other error code is treated like %NULL, and will cause an %ESTALE error | |
193 | * for callers of exportfs_decode_fh(). | |
194 | * Any suitable dentry can be returned including, if necessary, a new dentry | |
195 | * created with d_alloc_root. The caller can then find any other extant | |
196 | * dentries by following the d_alias links. | |
2596110a CH |
197 | * |
198 | * fh_to_parent: | |
199 | * Same as @fh_to_dentry, except that it returns a pointer to the parent | |
200 | * dentry if it was encoded into the filehandle fragment by @encode_fh. | |
201 | * | |
a5694255 CH |
202 | * get_name: |
203 | * @get_name should find a name for the given @child in the given @parent | |
204 | * directory. The name should be stored in the @name (with the | |
cd1a406f | 205 | * understanding that it is already pointing to a %NAME_MAX+1 sized |
a5694255 CH |
206 | * buffer. get_name() should return %0 on success, a negative error code |
207 | * or error. @get_name will be called without @parent->i_mutex held. | |
208 | * | |
209 | * get_parent: | |
210 | * @get_parent should find the parent directory for the given @child which | |
211 | * is also a directory. In the event that it cannot be found, or storage | |
212 | * space cannot be allocated, a %ERR_PTR should be returned. | |
213 | * | |
f501912a BM |
214 | * commit_metadata: |
215 | * @commit_metadata should commit metadata changes to stable storage. | |
216 | * | |
a5694255 CH |
217 | * Locking rules: |
218 | * get_parent is called with child->d_inode->i_mutex down | |
219 | * get_name is not (which is possibly inconsistent) | |
220 | */ | |
221 | ||
222 | struct export_operations { | |
b0b0382b AV |
223 | int (*encode_fh)(struct inode *inode, __u32 *fh, int *max_len, |
224 | struct inode *parent); | |
2596110a CH |
225 | struct dentry * (*fh_to_dentry)(struct super_block *sb, struct fid *fid, |
226 | int fh_len, int fh_type); | |
227 | struct dentry * (*fh_to_parent)(struct super_block *sb, struct fid *fid, | |
228 | int fh_len, int fh_type); | |
a5694255 CH |
229 | int (*get_name)(struct dentry *parent, char *name, |
230 | struct dentry *child); | |
231 | struct dentry * (*get_parent)(struct dentry *child); | |
f501912a | 232 | int (*commit_metadata)(struct inode *inode); |
7fbc1067 CH |
233 | |
234 | int (*get_uuid)(struct super_block *sb, u8 *buf, u32 *len, u64 *offset); | |
235 | int (*map_blocks)(struct inode *inode, loff_t offset, | |
236 | u64 len, struct iomap *iomap, | |
237 | bool write, u32 *device_generation); | |
238 | int (*commit_blocks)(struct inode *inode, struct iomap *iomaps, | |
239 | int nr_iomaps, struct iattr *iattr); | |
7f84b488 JL |
240 | #define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */ |
241 | #define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */ | |
242 | #define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */ | |
01cbf385 | 243 | #define EXPORT_OP_REMOTE_FS (0x8) /* Filesystem is remote */ |
716a8bc7 TM |
244 | #define EXPORT_OP_NOATOMIC_ATTR (0x10) /* Filesystem cannot supply |
245 | atomic attribute updates | |
246 | */ | |
dcb779fc | 247 | #define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */ |
2dd10de8 | 248 | #define EXPORT_OP_ASYNC_LOCK (0x40) /* fs can do async lock request */ |
daab110e | 249 | unsigned long flags; |
a5694255 CH |
250 | }; |
251 | ||
2dd10de8 AA |
252 | /** |
253 | * exportfs_lock_op_is_async() - export op supports async lock operation | |
254 | * @export_ops: the nfs export operations to check | |
255 | * | |
256 | * Returns true if the nfs export_operations structure has | |
257 | * EXPORT_OP_ASYNC_LOCK in their flags set | |
258 | */ | |
259 | static inline bool | |
260 | exportfs_lock_op_is_async(const struct export_operations *export_ops) | |
261 | { | |
262 | return export_ops->flags & EXPORT_OP_ASYNC_LOCK; | |
263 | } | |
264 | ||
711c7bf9 | 265 | extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid, |
304e9c83 AG |
266 | int *max_len, struct inode *parent, |
267 | int flags); | |
6e91ea2b | 268 | extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, |
b5287827 | 269 | int *max_len, int flags); |
304e9c83 | 270 | |
66c62769 AG |
271 | static inline bool exportfs_can_encode_fid(const struct export_operations *nop) |
272 | { | |
64343119 | 273 | return !nop || nop->encode_fh; |
66c62769 AG |
274 | } |
275 | ||
276 | static inline bool exportfs_can_decode_fh(const struct export_operations *nop) | |
277 | { | |
278 | return nop && nop->fh_to_dentry; | |
279 | } | |
280 | ||
281 | static inline bool exportfs_can_encode_fh(const struct export_operations *nop, | |
282 | int fh_flags) | |
283 | { | |
284 | /* | |
285 | * If a non-decodeable file handle was requested, we only need to make | |
64343119 | 286 | * sure that filesystem did not opt-out of encoding fid. |
66c62769 AG |
287 | */ |
288 | if (fh_flags & EXPORT_FH_FID) | |
289 | return exportfs_can_encode_fid(nop); | |
290 | ||
291 | /* | |
292 | * If a decodeable file handle was requested, we need to make sure that | |
293 | * filesystem can also decode file handles. | |
294 | */ | |
295 | return exportfs_can_decode_fh(nop); | |
296 | } | |
297 | ||
304e9c83 AG |
298 | static inline int exportfs_encode_fid(struct inode *inode, struct fid *fid, |
299 | int *max_len) | |
300 | { | |
301 | return exportfs_encode_inode_fh(inode, fid, max_len, NULL, | |
302 | EXPORT_FH_FID); | |
303 | } | |
304 | ||
d045465f TM |
305 | extern struct dentry *exportfs_decode_fh_raw(struct vfsmount *mnt, |
306 | struct fid *fid, int fh_len, | |
307 | int fileid_type, | |
308 | int (*acceptable)(void *, struct dentry *), | |
309 | void *context); | |
6e91ea2b | 310 | extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid, |
d37065cd CH |
311 | int fh_len, int fileid_type, int (*acceptable)(void *, struct dentry *), |
312 | void *context); | |
313 | ||
2596110a CH |
314 | /* |
315 | * Generic helpers for filesystems. | |
316 | */ | |
e21fc203 AG |
317 | int generic_encode_ino32_fh(struct inode *inode, __u32 *fh, int *max_len, |
318 | struct inode *parent); | |
d9e5d922 | 319 | struct dentry *generic_fh_to_dentry(struct super_block *sb, |
2596110a CH |
320 | struct fid *fid, int fh_len, int fh_type, |
321 | struct inode *(*get_inode) (struct super_block *sb, u64 ino, u32 gen)); | |
d9e5d922 | 322 | struct dentry *generic_fh_to_parent(struct super_block *sb, |
2596110a CH |
323 | struct fid *fid, int fh_len, int fh_type, |
324 | struct inode *(*get_inode) (struct super_block *sb, u64 ino, u32 gen)); | |
325 | ||
a5694255 | 326 | #endif /* LINUX_EXPORTFS_H */ |