diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/freevxfs/vxfs_lookup.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/freevxfs/vxfs_lookup.c')
-rw-r--r-- | fs/freevxfs/vxfs_lookup.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/fs/freevxfs/vxfs_lookup.c b/fs/freevxfs/vxfs_lookup.c new file mode 100644 index 00000000000..506ae251d2c --- /dev/null +++ b/fs/freevxfs/vxfs_lookup.c | |||
@@ -0,0 +1,328 @@ | |||
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> | ||
39 | #include <linux/smp_lock.h> | ||
40 | |||
41 | #include "vxfs.h" | ||
42 | #include "vxfs_dir.h" | ||
43 | #include "vxfs_inode.h" | ||
44 | #include "vxfs_extern.h" | ||
45 | |||
46 | /* | ||
47 | * Number of VxFS blocks per page. | ||
48 | */ | ||
49 | #define VXFS_BLOCK_PER_PAGE(sbp) ((PAGE_CACHE_SIZE / (sbp)->s_blocksize)) | ||
50 | |||
51 | |||
52 | static struct dentry * vxfs_lookup(struct inode *, struct dentry *, struct nameidata *); | ||
53 | static int vxfs_readdir(struct file *, void *, filldir_t); | ||
54 | |||
55 | struct inode_operations vxfs_dir_inode_ops = { | ||
56 | .lookup = vxfs_lookup, | ||
57 | }; | ||
58 | |||
59 | struct file_operations vxfs_dir_operations = { | ||
60 | .readdir = vxfs_readdir, | ||
61 | }; | ||
62 | |||
63 | |||
64 | static __inline__ u_long | ||
65 | dir_pages(struct inode *inode) | ||
66 | { | ||
67 | return (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | ||
68 | } | ||
69 | |||
70 | static __inline__ u_long | ||
71 | dir_blocks(struct inode *ip) | ||
72 | { | ||
73 | u_long bsize = ip->i_sb->s_blocksize; | ||
74 | return (ip->i_size + bsize - 1) & ~(bsize - 1); | ||
75 | } | ||
76 | |||
77 | /* | ||
78 | * NOTE! unlike strncmp, vxfs_match returns 1 for success, 0 for failure. | ||
79 | * | ||
80 | * len <= VXFS_NAMELEN and de != NULL are guaranteed by caller. | ||
81 | */ | ||
82 | static __inline__ int | ||
83 | vxfs_match(int len, const char * const name, struct vxfs_direct *de) | ||
84 | { | ||
85 | if (len != de->d_namelen) | ||
86 | return 0; | ||
87 | if (!de->d_ino) | ||
88 | return 0; | ||
89 | return !memcmp(name, de->d_name, len); | ||
90 | } | ||
91 | |||
92 | static __inline__ struct vxfs_direct * | ||
93 | vxfs_next_entry(struct vxfs_direct *de) | ||
94 | { | ||
95 | return ((struct vxfs_direct *)((char*)de + de->d_reclen)); | ||
96 | } | ||
97 | |||
98 | /** | ||
99 | * vxfs_find_entry - find a mathing directory entry for a dentry | ||
100 | * @ip: directory inode | ||
101 | * @dp: dentry for which we want to find a direct | ||
102 | * @ppp: gets filled with the page the return value sits in | ||
103 | * | ||
104 | * Description: | ||
105 | * vxfs_find_entry finds a &struct vxfs_direct for the VFS directory | ||
106 | * cache entry @dp. @ppp will be filled with the page the return | ||
107 | * value resides in. | ||
108 | * | ||
109 | * Returns: | ||
110 | * The wanted direct on success, else a NULL pointer. | ||
111 | */ | ||
112 | static struct vxfs_direct * | ||
113 | vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp) | ||
114 | { | ||
115 | u_long npages, page, nblocks, pblocks, block; | ||
116 | u_long bsize = ip->i_sb->s_blocksize; | ||
117 | const char *name = dp->d_name.name; | ||
118 | int namelen = dp->d_name.len; | ||
119 | |||
120 | npages = dir_pages(ip); | ||
121 | nblocks = dir_blocks(ip); | ||
122 | pblocks = VXFS_BLOCK_PER_PAGE(ip->i_sb); | ||
123 | |||
124 | for (page = 0; page < npages; page++) { | ||
125 | caddr_t kaddr; | ||
126 | struct page *pp; | ||
127 | |||
128 | pp = vxfs_get_page(ip->i_mapping, page); | ||
129 | if (IS_ERR(pp)) | ||
130 | continue; | ||
131 | kaddr = (caddr_t)page_address(pp); | ||
132 | |||
133 | for (block = 0; block <= nblocks && block <= pblocks; block++) { | ||
134 | caddr_t baddr, limit; | ||
135 | struct vxfs_dirblk *dbp; | ||
136 | struct vxfs_direct *de; | ||
137 | |||
138 | baddr = kaddr + (block * bsize); | ||
139 | limit = baddr + bsize - VXFS_DIRLEN(1); | ||
140 | |||
141 | dbp = (struct vxfs_dirblk *)baddr; | ||
142 | de = (struct vxfs_direct *)(baddr + VXFS_DIRBLKOV(dbp)); | ||
143 | |||
144 | for (; (caddr_t)de <= limit; de = vxfs_next_entry(de)) { | ||
145 | if (!de->d_reclen) | ||
146 | break; | ||
147 | if (!de->d_ino) | ||
148 | continue; | ||
149 | if (vxfs_match(namelen, name, de)) { | ||
150 | *ppp = pp; | ||
151 | return (de); | ||
152 | } | ||
153 | } | ||
154 | } | ||
155 | vxfs_put_page(pp); | ||
156 | } | ||
157 | |||
158 | return NULL; | ||
159 | } | ||
160 | |||
161 | /** | ||
162 | * vxfs_inode_by_name - find inode number for dentry | ||
163 | * @dip: directory to search in | ||
164 | * @dp: dentry we seach for | ||
165 | * | ||
166 | * Description: | ||
167 | * vxfs_inode_by_name finds out the inode number of | ||
168 | * the path component described by @dp in @dip. | ||
169 | * | ||
170 | * Returns: | ||
171 | * The wanted inode number on success, else Zero. | ||
172 | */ | ||
173 | static ino_t | ||
174 | vxfs_inode_by_name(struct inode *dip, struct dentry *dp) | ||
175 | { | ||
176 | struct vxfs_direct *de; | ||
177 | struct page *pp; | ||
178 | ino_t ino = 0; | ||
179 | |||
180 | de = vxfs_find_entry(dip, dp, &pp); | ||
181 | if (de) { | ||
182 | ino = de->d_ino; | ||
183 | kunmap(pp); | ||
184 | page_cache_release(pp); | ||
185 | } | ||
186 | |||
187 | return (ino); | ||
188 | } | ||
189 | |||
190 | /** | ||
191 | * vxfs_lookup - lookup pathname component | ||
192 | * @dip: dir in which we lookup | ||
193 | * @dp: dentry we lookup | ||
194 | * @nd: lookup nameidata | ||
195 | * | ||
196 | * Description: | ||
197 | * vxfs_lookup tries to lookup the pathname component described | ||
198 | * by @dp in @dip. | ||
199 | * | ||
200 | * Returns: | ||
201 | * A NULL-pointer on success, else an negative error code encoded | ||
202 | * in the return pointer. | ||
203 | */ | ||
204 | static struct dentry * | ||
205 | vxfs_lookup(struct inode *dip, struct dentry *dp, struct nameidata *nd) | ||
206 | { | ||
207 | struct inode *ip = NULL; | ||
208 | ino_t ino; | ||
209 | |||
210 | if (dp->d_name.len > VXFS_NAMELEN) | ||
211 | return ERR_PTR(-ENAMETOOLONG); | ||
212 | |||
213 | lock_kernel(); | ||
214 | ino = vxfs_inode_by_name(dip, dp); | ||
215 | if (ino) { | ||
216 | ip = iget(dip->i_sb, ino); | ||
217 | if (!ip) { | ||
218 | unlock_kernel(); | ||
219 | return ERR_PTR(-EACCES); | ||
220 | } | ||
221 | } | ||
222 | unlock_kernel(); | ||
223 | d_add(dp, ip); | ||
224 | return NULL; | ||
225 | } | ||
226 | |||
227 | /** | ||
228 | * vxfs_readdir - read a directory | ||
229 | * @fp: the directory to read | ||
230 | * @retp: return buffer | ||
231 | * @filler: filldir callback | ||
232 | * | ||
233 | * Description: | ||
234 | * vxfs_readdir fills @retp with directory entries from @fp | ||
235 | * using the VFS supplied callback @filler. | ||
236 | * | ||
237 | * Returns: | ||
238 | * Zero. | ||
239 | */ | ||
240 | static int | ||
241 | vxfs_readdir(struct file *fp, void *retp, filldir_t filler) | ||
242 | { | ||
243 | struct inode *ip = fp->f_dentry->d_inode; | ||
244 | struct super_block *sbp = ip->i_sb; | ||
245 | u_long bsize = sbp->s_blocksize; | ||
246 | u_long page, npages, block, pblocks, nblocks, offset; | ||
247 | loff_t pos; | ||
248 | |||
249 | switch ((long)fp->f_pos) { | ||
250 | case 0: | ||
251 | if (filler(retp, ".", 1, fp->f_pos, ip->i_ino, DT_DIR) < 0) | ||
252 | goto out; | ||
253 | fp->f_pos++; | ||
254 | /* fallthrough */ | ||
255 | case 1: | ||
256 | if (filler(retp, "..", 2, fp->f_pos, VXFS_INO(ip)->vii_dotdot, DT_DIR) < 0) | ||
257 | goto out; | ||
258 | fp->f_pos++; | ||
259 | /* fallthrough */ | ||
260 | } | ||
261 | |||
262 | pos = fp->f_pos - 2; | ||
263 | |||
264 | if (pos > VXFS_DIRROUND(ip->i_size)) { | ||
265 | unlock_kernel(); | ||
266 | return 0; | ||
267 | } | ||
268 | |||
269 | npages = dir_pages(ip); | ||
270 | nblocks = dir_blocks(ip); | ||
271 | pblocks = VXFS_BLOCK_PER_PAGE(sbp); | ||
272 | |||
273 | page = pos >> PAGE_CACHE_SHIFT; | ||
274 | offset = pos & ~PAGE_CACHE_MASK; | ||
275 | block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks; | ||
276 | |||
277 | for (; page < npages; page++, block = 0) { | ||
278 | caddr_t kaddr; | ||
279 | struct page *pp; | ||
280 | |||
281 | pp = vxfs_get_page(ip->i_mapping, page); | ||
282 | if (IS_ERR(pp)) | ||
283 | continue; | ||
284 | kaddr = (caddr_t)page_address(pp); | ||
285 | |||
286 | for (; block <= nblocks && block <= pblocks; block++) { | ||
287 | caddr_t baddr, limit; | ||
288 | struct vxfs_dirblk *dbp; | ||
289 | struct vxfs_direct *de; | ||
290 | |||
291 | baddr = kaddr + (block * bsize); | ||
292 | limit = baddr + bsize - VXFS_DIRLEN(1); | ||
293 | |||
294 | dbp = (struct vxfs_dirblk *)baddr; | ||
295 | de = (struct vxfs_direct *) | ||
296 | (offset ? | ||
297 | (kaddr + offset) : | ||
298 | (baddr + VXFS_DIRBLKOV(dbp))); | ||
299 | |||
300 | for (; (caddr_t)de <= limit; de = vxfs_next_entry(de)) { | ||
301 | int over; | ||
302 | |||
303 | if (!de->d_reclen) | ||
304 | break; | ||
305 | if (!de->d_ino) | ||
306 | continue; | ||
307 | |||
308 | offset = (caddr_t)de - kaddr; | ||
309 | over = filler(retp, de->d_name, de->d_namelen, | ||
310 | ((page << PAGE_CACHE_SHIFT) | offset) + 2, | ||
311 | de->d_ino, DT_UNKNOWN); | ||
312 | if (over) { | ||
313 | vxfs_put_page(pp); | ||
314 | goto done; | ||
315 | } | ||
316 | } | ||
317 | offset = 0; | ||
318 | } | ||
319 | vxfs_put_page(pp); | ||
320 | offset = 0; | ||
321 | } | ||
322 | |||
323 | done: | ||
324 | fp->f_pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2; | ||
325 | out: | ||
326 | unlock_kernel(); | ||
327 | return 0; | ||
328 | } | ||