xref: /openbmc/linux/fs/ubifs/misc.h (revision fcf44196)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * This file is part of UBIFS.
4  *
5  * Copyright (C) 2006-2008 Nokia Corporation
6  *
7  * Authors: Artem Bityutskiy (Битюцкий Артём)
8  *          Adrian Hunter
9  */
10 
11 /*
12  * This file contains miscellaneous helper functions.
13  */
14 
15 #ifndef __UBIFS_MISC_H__
16 #define __UBIFS_MISC_H__
17 
18 /**
19  * ubifs_zn_dirty - check if znode is dirty.
20  * @znode: znode to check
21  *
22  * This helper function returns %1 if @znode is dirty and %0 otherwise.
23  */
ubifs_zn_dirty(const struct ubifs_znode * znode)24 static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
25 {
26 	return !!test_bit(DIRTY_ZNODE, &znode->flags);
27 }
28 
29 /**
30  * ubifs_zn_obsolete - check if znode is obsolete.
31  * @znode: znode to check
32  *
33  * This helper function returns %1 if @znode is obsolete and %0 otherwise.
34  */
ubifs_zn_obsolete(const struct ubifs_znode * znode)35 static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode)
36 {
37 	return !!test_bit(OBSOLETE_ZNODE, &znode->flags);
38 }
39 
40 /**
41  * ubifs_zn_cow - check if znode has to be copied on write.
42  * @znode: znode to check
43  *
44  * This helper function returns %1 if @znode is has COW flag set and %0
45  * otherwise.
46  */
ubifs_zn_cow(const struct ubifs_znode * znode)47 static inline int ubifs_zn_cow(const struct ubifs_znode *znode)
48 {
49 	return !!test_bit(COW_ZNODE, &znode->flags);
50 }
51 
52 /**
53  * ubifs_wake_up_bgt - wake up background thread.
54  * @c: UBIFS file-system description object
55  */
ubifs_wake_up_bgt(struct ubifs_info * c)56 static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
57 {
58 	if (c->bgt && !c->need_bgt) {
59 		c->need_bgt = 1;
60 		wake_up_process(c->bgt);
61 	}
62 }
63 
64 /**
65  * ubifs_tnc_find_child - find next child in znode.
66  * @znode: znode to search at
67  * @start: the zbranch index to start at
68  *
69  * This helper function looks for znode child starting at index @start. Returns
70  * the child or %NULL if no children were found.
71  */
72 static inline struct ubifs_znode *
ubifs_tnc_find_child(struct ubifs_znode * znode,int start)73 ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
74 {
75 	while (start < znode->child_cnt) {
76 		if (znode->zbranch[start].znode)
77 			return znode->zbranch[start].znode;
78 		start += 1;
79 	}
80 
81 	return NULL;
82 }
83 
84 /**
85  * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
86  * @inode: the VFS 'struct inode' pointer
87  */
ubifs_inode(const struct inode * inode)88 static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
89 {
90 	return container_of(inode, struct ubifs_inode, vfs_inode);
91 }
92 
93 /**
94  * ubifs_compr_present - check if compressor was compiled in.
95  * @compr_type: compressor type to check
96  * @c: the UBIFS file-system description object
97  *
98  * This function returns %1 of compressor of type @compr_type is present, and
99  * %0 if not.
100  */
ubifs_compr_present(struct ubifs_info * c,int compr_type)101 static inline int ubifs_compr_present(struct ubifs_info *c, int compr_type)
102 {
103 	ubifs_assert(c, compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
104 	return !!ubifs_compressors[compr_type]->capi_name;
105 }
106 
107 /**
108  * ubifs_compr_name - get compressor name string by its type.
109  * @compr_type: compressor type
110  * @c: the UBIFS file-system description object
111  *
112  * This function returns compressor type string.
113  */
ubifs_compr_name(struct ubifs_info * c,int compr_type)114 static inline const char *ubifs_compr_name(struct ubifs_info *c, int compr_type)
115 {
116 	ubifs_assert(c, compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
117 	return ubifs_compressors[compr_type]->name;
118 }
119 
120 /**
121  * ubifs_wbuf_sync - synchronize write-buffer.
122  * @wbuf: write-buffer to synchronize
123  *
124  * This is the same as 'ubifs_wbuf_sync_nolock()' but it does not assume
125  * that the write-buffer is already locked.
126  */
ubifs_wbuf_sync(struct ubifs_wbuf * wbuf)127 static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
128 {
129 	int err;
130 
131 	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
132 	err = ubifs_wbuf_sync_nolock(wbuf);
133 	mutex_unlock(&wbuf->io_mutex);
134 	return err;
135 }
136 
137 /**
138  * ubifs_encode_dev - encode device node IDs.
139  * @dev: UBIFS device node information
140  * @rdev: device IDs to encode
141  *
142  * This is a helper function which encodes major/minor numbers of a device node
143  * into UBIFS device node description. We use standard Linux "new" and "huge"
144  * encodings.
145  */
ubifs_encode_dev(union ubifs_dev_desc * dev,dev_t rdev)146 static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
147 {
148 	dev->new = cpu_to_le32(new_encode_dev(rdev));
149 	return sizeof(dev->new);
150 }
151 
152 /**
153  * ubifs_add_dirt - add dirty space to LEB properties.
154  * @c: the UBIFS file-system description object
155  * @lnum: LEB to add dirty space for
156  * @dirty: dirty space to add
157  *
158  * This is a helper function which increased amount of dirty LEB space. Returns
159  * zero in case of success and a negative error code in case of failure.
160  */
ubifs_add_dirt(struct ubifs_info * c,int lnum,int dirty)161 static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
162 {
163 	return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
164 }
165 
166 /**
167  * ubifs_return_leb - return LEB to lprops.
168  * @c: the UBIFS file-system description object
169  * @lnum: LEB to return
170  *
171  * This helper function cleans the "taken" flag of a logical eraseblock in the
172  * lprops. Returns zero in case of success and a negative error code in case of
173  * failure.
174  */
ubifs_return_leb(struct ubifs_info * c,int lnum)175 static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
176 {
177 	return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
178 				   LPROPS_TAKEN, 0);
179 }
180 
181 /**
182  * ubifs_idx_node_sz - return index node size.
183  * @c: the UBIFS file-system description object
184  * @child_cnt: number of children of this index node
185  */
ubifs_idx_node_sz(const struct ubifs_info * c,int child_cnt)186 static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
187 {
188 	return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len + c->hash_len)
189 				   * child_cnt;
190 }
191 
192 /**
193  * ubifs_idx_branch - return pointer to an index branch.
194  * @c: the UBIFS file-system description object
195  * @idx: index node
196  * @bnum: branch number
197  */
198 static inline
ubifs_idx_branch(const struct ubifs_info * c,const struct ubifs_idx_node * idx,int bnum)199 struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
200 				      const struct ubifs_idx_node *idx,
201 				      int bnum)
202 {
203 	return (struct ubifs_branch *)((void *)idx->branches +
204 			(UBIFS_BRANCH_SZ + c->key_len + c->hash_len) * bnum);
205 }
206 
207 /**
208  * ubifs_idx_key - return pointer to an index key.
209  * @c: the UBIFS file-system description object
210  * @idx: index node
211  */
ubifs_idx_key(const struct ubifs_info * c,const struct ubifs_idx_node * idx)212 static inline void *ubifs_idx_key(const struct ubifs_info *c,
213 				  const struct ubifs_idx_node *idx)
214 {
215 	return (void *)((struct ubifs_branch *)idx->branches)->key;
216 }
217 
218 /**
219  * ubifs_tnc_lookup - look up a file-system node.
220  * @c: UBIFS file-system description object
221  * @key: node key to lookup
222  * @node: the node is returned here
223  *
224  * This function look up and reads node with key @key. The caller has to make
225  * sure the @node buffer is large enough to fit the node. Returns zero in case
226  * of success, %-ENOENT if the node was not found, and a negative error code in
227  * case of failure.
228  */
ubifs_tnc_lookup(struct ubifs_info * c,const union ubifs_key * key,void * node)229 static inline int ubifs_tnc_lookup(struct ubifs_info *c,
230 				   const union ubifs_key *key, void *node)
231 {
232 	return ubifs_tnc_locate(c, key, node, NULL, NULL);
233 }
234 
235 /**
236  * ubifs_get_lprops - get reference to LEB properties.
237  * @c: the UBIFS file-system description object
238  *
239  * This function locks lprops. Lprops have to be unlocked by
240  * 'ubifs_release_lprops()'.
241  */
ubifs_get_lprops(struct ubifs_info * c)242 static inline void ubifs_get_lprops(struct ubifs_info *c)
243 {
244 	mutex_lock(&c->lp_mutex);
245 }
246 
247 /**
248  * ubifs_release_lprops - release lprops lock.
249  * @c: the UBIFS file-system description object
250  *
251  * This function has to be called after each 'ubifs_get_lprops()' call to
252  * unlock lprops.
253  */
ubifs_release_lprops(struct ubifs_info * c)254 static inline void ubifs_release_lprops(struct ubifs_info *c)
255 {
256 	ubifs_assert(c, mutex_is_locked(&c->lp_mutex));
257 	ubifs_assert(c, c->lst.empty_lebs >= 0 &&
258 		     c->lst.empty_lebs <= c->main_lebs);
259 	mutex_unlock(&c->lp_mutex);
260 }
261 
262 /**
263  * ubifs_next_log_lnum - switch to the next log LEB.
264  * @c: UBIFS file-system description object
265  * @lnum: current log LEB
266  *
267  * This helper function returns the log LEB number which goes next after LEB
268  * 'lnum'.
269  */
ubifs_next_log_lnum(const struct ubifs_info * c,int lnum)270 static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum)
271 {
272 	lnum += 1;
273 	if (lnum > c->log_last)
274 		lnum = UBIFS_LOG_LNUM;
275 
276 	return lnum;
277 }
278 
ubifs_xattr_max_cnt(struct ubifs_info * c)279 static inline int ubifs_xattr_max_cnt(struct ubifs_info *c)
280 {
281 	int max_xattrs = (c->leb_size / 2) / UBIFS_INO_NODE_SZ;
282 
283 	ubifs_assert(c, max_xattrs < c->max_orphans);
284 	return max_xattrs;
285 }
286 
287 const char *ubifs_assert_action_name(struct ubifs_info *c);
288 
289 #endif /* __UBIFS_MISC_H__ */
290