Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (c) 2000-2001 Christoph Hellwig. | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions, and the following disclaimer, | |
10 | * without modification. | |
11 | * 2. The name of the author may not be used to endorse or promote products | |
12 | * derived from this software without specific prior written permission. | |
13 | * | |
14 | * Alternatively, this software may be distributed under the terms of the | |
15 | * GNU General Public License ("GPL"). | |
16 | * | |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR | |
21 | * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
27 | * SUCH DAMAGE. | |
28 | */ | |
29 | ||
30 | /* | |
31 | * Veritas filesystem driver - lookup and other directory related code. | |
32 | */ | |
33 | #include <linux/fs.h> | |
34 | #include <linux/time.h> | |
35 | #include <linux/mm.h> | |
36 | #include <linux/highmem.h> | |
37 | #include <linux/kernel.h> | |
38 | #include <linux/pagemap.h> | |
1da177e4 LT |
39 | |
40 | #include "vxfs.h" | |
41 | #include "vxfs_dir.h" | |
42 | #include "vxfs_inode.h" | |
43 | #include "vxfs_extern.h" | |
44 | ||
45 | /* | |
46 | * Number of VxFS blocks per page. | |
47 | */ | |
48 | #define VXFS_BLOCK_PER_PAGE(sbp) ((PAGE_CACHE_SIZE / (sbp)->s_blocksize)) | |
49 | ||
50 | ||
00cd8dd3 | 51 | static struct dentry * vxfs_lookup(struct inode *, struct dentry *, unsigned int); |
1da177e4 LT |
52 | static int vxfs_readdir(struct file *, void *, filldir_t); |
53 | ||
754661f1 | 54 | const struct inode_operations vxfs_dir_inode_ops = { |
1da177e4 LT |
55 | .lookup = vxfs_lookup, |
56 | }; | |
57 | ||
4b6f5d20 | 58 | const struct file_operations vxfs_dir_operations = { |
ca572727 B |
59 | .llseek = generic_file_llseek, |
60 | .read = generic_read_dir, | |
1da177e4 LT |
61 | .readdir = vxfs_readdir, |
62 | }; | |
63 | ||
64 | ||
8cb681b9 | 65 | static inline u_long |
1da177e4 LT |
66 | dir_pages(struct inode *inode) |
67 | { | |
68 | return (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
69 | } | |
70 | ||
8cb681b9 | 71 | static inline u_long |
1da177e4 LT |
72 | dir_blocks(struct inode *ip) |
73 | { | |
74 | u_long bsize = ip->i_sb->s_blocksize; | |
75 | return (ip->i_size + bsize - 1) & ~(bsize - 1); | |
76 | } | |
77 | ||
78 | /* | |
79 | * NOTE! unlike strncmp, vxfs_match returns 1 for success, 0 for failure. | |
80 | * | |
81 | * len <= VXFS_NAMELEN and de != NULL are guaranteed by caller. | |
82 | */ | |
8cb681b9 | 83 | static inline int |
1da177e4 LT |
84 | vxfs_match(int len, const char * const name, struct vxfs_direct *de) |
85 | { | |
86 | if (len != de->d_namelen) | |
87 | return 0; | |
88 | if (!de->d_ino) | |
89 | return 0; | |
90 | return !memcmp(name, de->d_name, len); | |
91 | } | |
92 | ||
8cb681b9 | 93 | static inline struct vxfs_direct * |
1da177e4 LT |
94 | vxfs_next_entry(struct vxfs_direct *de) |
95 | { | |
96 | return ((struct vxfs_direct *)((char*)de + de->d_reclen)); | |
97 | } | |
98 | ||
99 | /** | |
100 | * vxfs_find_entry - find a mathing directory entry for a dentry | |
101 | * @ip: directory inode | |
102 | * @dp: dentry for which we want to find a direct | |
103 | * @ppp: gets filled with the page the return value sits in | |
104 | * | |
105 | * Description: | |
106 | * vxfs_find_entry finds a &struct vxfs_direct for the VFS directory | |
107 | * cache entry @dp. @ppp will be filled with the page the return | |
108 | * value resides in. | |
109 | * | |
110 | * Returns: | |
111 | * The wanted direct on success, else a NULL pointer. | |
112 | */ | |
113 | static struct vxfs_direct * | |
114 | vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp) | |
115 | { | |
116 | u_long npages, page, nblocks, pblocks, block; | |
117 | u_long bsize = ip->i_sb->s_blocksize; | |
118 | const char *name = dp->d_name.name; | |
119 | int namelen = dp->d_name.len; | |
120 | ||
121 | npages = dir_pages(ip); | |
122 | nblocks = dir_blocks(ip); | |
123 | pblocks = VXFS_BLOCK_PER_PAGE(ip->i_sb); | |
124 | ||
125 | for (page = 0; page < npages; page++) { | |
126 | caddr_t kaddr; | |
127 | struct page *pp; | |
128 | ||
129 | pp = vxfs_get_page(ip->i_mapping, page); | |
130 | if (IS_ERR(pp)) | |
131 | continue; | |
132 | kaddr = (caddr_t)page_address(pp); | |
133 | ||
134 | for (block = 0; block <= nblocks && block <= pblocks; block++) { | |
135 | caddr_t baddr, limit; | |
136 | struct vxfs_dirblk *dbp; | |
137 | struct vxfs_direct *de; | |
138 | ||
139 | baddr = kaddr + (block * bsize); | |
140 | limit = baddr + bsize - VXFS_DIRLEN(1); | |
141 | ||
142 | dbp = (struct vxfs_dirblk *)baddr; | |
143 | de = (struct vxfs_direct *)(baddr + VXFS_DIRBLKOV(dbp)); | |
144 | ||
145 | for (; (caddr_t)de <= limit; de = vxfs_next_entry(de)) { | |
146 | if (!de->d_reclen) | |
147 | break; | |
148 | if (!de->d_ino) | |
149 | continue; | |
150 | if (vxfs_match(namelen, name, de)) { | |
151 | *ppp = pp; | |
152 | return (de); | |
153 | } | |
154 | } | |
155 | } | |
156 | vxfs_put_page(pp); | |
157 | } | |
158 | ||
159 | return NULL; | |
160 | } | |
161 | ||
162 | /** | |
163 | * vxfs_inode_by_name - find inode number for dentry | |
164 | * @dip: directory to search in | |
25985edc | 165 | * @dp: dentry we search for |
1da177e4 LT |
166 | * |
167 | * Description: | |
168 | * vxfs_inode_by_name finds out the inode number of | |
169 | * the path component described by @dp in @dip. | |
170 | * | |
171 | * Returns: | |
172 | * The wanted inode number on success, else Zero. | |
173 | */ | |
174 | static ino_t | |
175 | vxfs_inode_by_name(struct inode *dip, struct dentry *dp) | |
176 | { | |
177 | struct vxfs_direct *de; | |
178 | struct page *pp; | |
179 | ino_t ino = 0; | |
180 | ||
181 | de = vxfs_find_entry(dip, dp, &pp); | |
182 | if (de) { | |
183 | ino = de->d_ino; | |
184 | kunmap(pp); | |
185 | page_cache_release(pp); | |
186 | } | |
187 | ||
188 | return (ino); | |
189 | } | |
190 | ||
191 | /** | |
192 | * vxfs_lookup - lookup pathname component | |
193 | * @dip: dir in which we lookup | |
194 | * @dp: dentry we lookup | |
195 | * @nd: lookup nameidata | |
196 | * | |
197 | * Description: | |
198 | * vxfs_lookup tries to lookup the pathname component described | |
199 | * by @dp in @dip. | |
200 | * | |
201 | * Returns: | |
202 | * A NULL-pointer on success, else an negative error code encoded | |
203 | * in the return pointer. | |
204 | */ | |
205 | static struct dentry * | |
00cd8dd3 | 206 | vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags) |
1da177e4 LT |
207 | { |
208 | struct inode *ip = NULL; | |
209 | ino_t ino; | |
210 | ||
211 | if (dp->d_name.len > VXFS_NAMELEN) | |
212 | return ERR_PTR(-ENAMETOOLONG); | |
213 | ||
1da177e4 LT |
214 | ino = vxfs_inode_by_name(dip, dp); |
215 | if (ino) { | |
d0b07948 | 216 | ip = vxfs_iget(dip->i_sb, ino); |
6d7bccc2 | 217 | if (IS_ERR(ip)) |
d0b07948 | 218 | return ERR_CAST(ip); |
1da177e4 | 219 | } |
1da177e4 LT |
220 | d_add(dp, ip); |
221 | return NULL; | |
222 | } | |
223 | ||
224 | /** | |
225 | * vxfs_readdir - read a directory | |
226 | * @fp: the directory to read | |
227 | * @retp: return buffer | |
228 | * @filler: filldir callback | |
229 | * | |
230 | * Description: | |
231 | * vxfs_readdir fills @retp with directory entries from @fp | |
232 | * using the VFS supplied callback @filler. | |
233 | * | |
234 | * Returns: | |
235 | * Zero. | |
236 | */ | |
237 | static int | |
238 | vxfs_readdir(struct file *fp, void *retp, filldir_t filler) | |
239 | { | |
6a90cd24 | 240 | struct inode *ip = fp->f_path.dentry->d_inode; |
1da177e4 LT |
241 | struct super_block *sbp = ip->i_sb; |
242 | u_long bsize = sbp->s_blocksize; | |
243 | u_long page, npages, block, pblocks, nblocks, offset; | |
244 | loff_t pos; | |
245 | ||
246 | switch ((long)fp->f_pos) { | |
247 | case 0: | |
248 | if (filler(retp, ".", 1, fp->f_pos, ip->i_ino, DT_DIR) < 0) | |
249 | goto out; | |
250 | fp->f_pos++; | |
251 | /* fallthrough */ | |
252 | case 1: | |
253 | if (filler(retp, "..", 2, fp->f_pos, VXFS_INO(ip)->vii_dotdot, DT_DIR) < 0) | |
254 | goto out; | |
255 | fp->f_pos++; | |
256 | /* fallthrough */ | |
257 | } | |
258 | ||
259 | pos = fp->f_pos - 2; | |
260 | ||
6d7bccc2 | 261 | if (pos > VXFS_DIRROUND(ip->i_size)) |
1da177e4 | 262 | return 0; |
1da177e4 LT |
263 | |
264 | npages = dir_pages(ip); | |
265 | nblocks = dir_blocks(ip); | |
266 | pblocks = VXFS_BLOCK_PER_PAGE(sbp); | |
267 | ||
268 | page = pos >> PAGE_CACHE_SHIFT; | |
269 | offset = pos & ~PAGE_CACHE_MASK; | |
270 | block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks; | |
271 | ||
272 | for (; page < npages; page++, block = 0) { | |
273 | caddr_t kaddr; | |
274 | struct page *pp; | |
275 | ||
276 | pp = vxfs_get_page(ip->i_mapping, page); | |
277 | if (IS_ERR(pp)) | |
278 | continue; | |
279 | kaddr = (caddr_t)page_address(pp); | |
280 | ||
281 | for (; block <= nblocks && block <= pblocks; block++) { | |
282 | caddr_t baddr, limit; | |
283 | struct vxfs_dirblk *dbp; | |
284 | struct vxfs_direct *de; | |
285 | ||
286 | baddr = kaddr + (block * bsize); | |
287 | limit = baddr + bsize - VXFS_DIRLEN(1); | |
288 | ||
289 | dbp = (struct vxfs_dirblk *)baddr; | |
290 | de = (struct vxfs_direct *) | |
291 | (offset ? | |
292 | (kaddr + offset) : | |
293 | (baddr + VXFS_DIRBLKOV(dbp))); | |
294 | ||
295 | for (; (caddr_t)de <= limit; de = vxfs_next_entry(de)) { | |
296 | int over; | |
297 | ||
298 | if (!de->d_reclen) | |
299 | break; | |
300 | if (!de->d_ino) | |
301 | continue; | |
302 | ||
303 | offset = (caddr_t)de - kaddr; | |
304 | over = filler(retp, de->d_name, de->d_namelen, | |
305 | ((page << PAGE_CACHE_SHIFT) | offset) + 2, | |
306 | de->d_ino, DT_UNKNOWN); | |
307 | if (over) { | |
308 | vxfs_put_page(pp); | |
309 | goto done; | |
310 | } | |
311 | } | |
312 | offset = 0; | |
313 | } | |
314 | vxfs_put_page(pp); | |
315 | offset = 0; | |
316 | } | |
317 | ||
318 | done: | |
319 | fp->f_pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2; | |
320 | out: | |
1da177e4 LT |
321 | return 0; |
322 | } |