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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
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
51static struct dentry * vxfs_lookup(struct inode *, struct dentry *, struct nameidata *);
52static int vxfs_readdir(struct file *, void *, filldir_t);
53
54const struct inode_operations vxfs_dir_inode_ops = {
55 .lookup = vxfs_lookup,
56};
57
58const struct file_operations vxfs_dir_operations = {
59 .llseek = generic_file_llseek,
60 .read = generic_read_dir,
61 .readdir = vxfs_readdir,
62};
63
64
65static inline u_long
66dir_pages(struct inode *inode)
67{
68 return (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
69}
70
71static inline u_long
72dir_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 */
83static inline int
84vxfs_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
93static inline struct vxfs_direct *
94vxfs_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 */
113static struct vxfs_direct *
114vxfs_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
165 * @dp: dentry we search for
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 */
174static ino_t
175vxfs_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 */
205static struct dentry *
206vxfs_lookup(struct inode *dip, struct dentry *dp, struct nameidata *nd)
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
214 ino = vxfs_inode_by_name(dip, dp);
215 if (ino) {
216 ip = vxfs_iget(dip->i_sb, ino);
217 if (IS_ERR(ip))
218 return ERR_CAST(ip);
219 }
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 */
237static int
238vxfs_readdir(struct file *fp, void *retp, filldir_t filler)
239{
240 struct inode *ip = fp->f_path.dentry->d_inode;
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
261 if (pos > VXFS_DIRROUND(ip->i_size))
262 return 0;
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
318done:
319 fp->f_pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2;
320out:
321 return 0;
322}
1/*
2 * Copyright (c) 2000-2001 Christoph Hellwig.
3 * Copyright (c) 2016 Krzysztof Blaszkowski
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions, and the following disclaimer,
11 * without modification.
12 * 2. The name of the author may not be used to endorse or promote products
13 * derived from this software without specific prior written permission.
14 *
15 * Alternatively, this software may be distributed under the terms of the
16 * GNU General Public License ("GPL").
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31/*
32 * Veritas filesystem driver - lookup and other directory related code.
33 */
34#include <linux/fs.h>
35#include <linux/time.h>
36#include <linux/mm.h>
37#include <linux/highmem.h>
38#include <linux/kernel.h>
39#include <linux/pagemap.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_SIZE / (sbp)->s_blocksize))
50
51
52static struct dentry * vxfs_lookup(struct inode *, struct dentry *, unsigned int);
53static int vxfs_readdir(struct file *, struct dir_context *);
54
55const struct inode_operations vxfs_dir_inode_ops = {
56 .lookup = vxfs_lookup,
57};
58
59const struct file_operations vxfs_dir_operations = {
60 .llseek = generic_file_llseek,
61 .read = generic_read_dir,
62 .iterate_shared = vxfs_readdir,
63};
64
65
66/**
67 * vxfs_find_entry - find a mathing directory entry for a dentry
68 * @ip: directory inode
69 * @dp: dentry for which we want to find a direct
70 * @ppp: gets filled with the page the return value sits in
71 *
72 * Description:
73 * vxfs_find_entry finds a &struct vxfs_direct for the VFS directory
74 * cache entry @dp. @ppp will be filled with the page the return
75 * value resides in.
76 *
77 * Returns:
78 * The wanted direct on success, else a NULL pointer.
79 */
80static struct vxfs_direct *
81vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp)
82{
83 u_long bsize = ip->i_sb->s_blocksize;
84 const char *name = dp->d_name.name;
85 int namelen = dp->d_name.len;
86 loff_t limit = VXFS_DIRROUND(ip->i_size);
87 struct vxfs_direct *de_exit = NULL;
88 loff_t pos = 0;
89 struct vxfs_sb_info *sbi = VXFS_SBI(ip->i_sb);
90
91 while (pos < limit) {
92 struct page *pp;
93 char *kaddr;
94 int pg_ofs = pos & ~PAGE_MASK;
95
96 pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
97 if (IS_ERR(pp))
98 return NULL;
99 kaddr = (char *)page_address(pp);
100
101 while (pg_ofs < PAGE_SIZE && pos < limit) {
102 struct vxfs_direct *de;
103
104 if ((pos & (bsize - 1)) < 4) {
105 struct vxfs_dirblk *dbp =
106 (struct vxfs_dirblk *)
107 (kaddr + (pos & ~PAGE_MASK));
108 int overhead = VXFS_DIRBLKOV(sbi, dbp);
109
110 pos += overhead;
111 pg_ofs += overhead;
112 }
113 de = (struct vxfs_direct *)(kaddr + pg_ofs);
114
115 if (!de->d_reclen) {
116 pos += bsize - 1;
117 pos &= ~(bsize - 1);
118 break;
119 }
120
121 pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
122 pos += fs16_to_cpu(sbi, de->d_reclen);
123 if (!de->d_ino)
124 continue;
125
126 if (namelen != fs16_to_cpu(sbi, de->d_namelen))
127 continue;
128 if (!memcmp(name, de->d_name, namelen)) {
129 *ppp = pp;
130 de_exit = de;
131 break;
132 }
133 }
134 if (!de_exit)
135 vxfs_put_page(pp);
136 else
137 break;
138 }
139
140 return de_exit;
141}
142
143/**
144 * vxfs_inode_by_name - find inode number for dentry
145 * @dip: directory to search in
146 * @dp: dentry we search for
147 *
148 * Description:
149 * vxfs_inode_by_name finds out the inode number of
150 * the path component described by @dp in @dip.
151 *
152 * Returns:
153 * The wanted inode number on success, else Zero.
154 */
155static ino_t
156vxfs_inode_by_name(struct inode *dip, struct dentry *dp)
157{
158 struct vxfs_direct *de;
159 struct page *pp;
160 ino_t ino = 0;
161
162 de = vxfs_find_entry(dip, dp, &pp);
163 if (de) {
164 ino = fs32_to_cpu(VXFS_SBI(dip->i_sb), de->d_ino);
165 kunmap(pp);
166 put_page(pp);
167 }
168
169 return (ino);
170}
171
172/**
173 * vxfs_lookup - lookup pathname component
174 * @dip: dir in which we lookup
175 * @dp: dentry we lookup
176 * @flags: lookup flags
177 *
178 * Description:
179 * vxfs_lookup tries to lookup the pathname component described
180 * by @dp in @dip.
181 *
182 * Returns:
183 * A NULL-pointer on success, else a negative error code encoded
184 * in the return pointer.
185 */
186static struct dentry *
187vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags)
188{
189 struct inode *ip = NULL;
190 ino_t ino;
191
192 if (dp->d_name.len > VXFS_NAMELEN)
193 return ERR_PTR(-ENAMETOOLONG);
194
195 ino = vxfs_inode_by_name(dip, dp);
196 if (ino) {
197 ip = vxfs_iget(dip->i_sb, ino);
198 if (IS_ERR(ip))
199 return ERR_CAST(ip);
200 }
201 d_add(dp, ip);
202 return NULL;
203}
204
205/**
206 * vxfs_readdir - read a directory
207 * @fp: the directory to read
208 * @retp: return buffer
209 * @filler: filldir callback
210 *
211 * Description:
212 * vxfs_readdir fills @retp with directory entries from @fp
213 * using the VFS supplied callback @filler.
214 *
215 * Returns:
216 * Zero.
217 */
218static int
219vxfs_readdir(struct file *fp, struct dir_context *ctx)
220{
221 struct inode *ip = file_inode(fp);
222 struct super_block *sbp = ip->i_sb;
223 u_long bsize = sbp->s_blocksize;
224 loff_t pos, limit;
225 struct vxfs_sb_info *sbi = VXFS_SBI(sbp);
226
227 if (ctx->pos == 0) {
228 if (!dir_emit_dot(fp, ctx))
229 goto out;
230 ctx->pos++;
231 }
232 if (ctx->pos == 1) {
233 if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
234 goto out;
235 ctx->pos++;
236 }
237
238 limit = VXFS_DIRROUND(ip->i_size);
239 if (ctx->pos > limit)
240 goto out;
241
242 pos = ctx->pos & ~3L;
243
244 while (pos < limit) {
245 struct page *pp;
246 char *kaddr;
247 int pg_ofs = pos & ~PAGE_MASK;
248 int rc = 0;
249
250 pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
251 if (IS_ERR(pp))
252 return -ENOMEM;
253
254 kaddr = (char *)page_address(pp);
255
256 while (pg_ofs < PAGE_SIZE && pos < limit) {
257 struct vxfs_direct *de;
258
259 if ((pos & (bsize - 1)) < 4) {
260 struct vxfs_dirblk *dbp =
261 (struct vxfs_dirblk *)
262 (kaddr + (pos & ~PAGE_MASK));
263 int overhead = VXFS_DIRBLKOV(sbi, dbp);
264
265 pos += overhead;
266 pg_ofs += overhead;
267 }
268 de = (struct vxfs_direct *)(kaddr + pg_ofs);
269
270 if (!de->d_reclen) {
271 pos += bsize - 1;
272 pos &= ~(bsize - 1);
273 break;
274 }
275
276 pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
277 pos += fs16_to_cpu(sbi, de->d_reclen);
278 if (!de->d_ino)
279 continue;
280
281 rc = dir_emit(ctx, de->d_name,
282 fs16_to_cpu(sbi, de->d_namelen),
283 fs32_to_cpu(sbi, de->d_ino),
284 DT_UNKNOWN);
285 if (!rc) {
286 /* the dir entry was not read, fix pos. */
287 pos -= fs16_to_cpu(sbi, de->d_reclen);
288 break;
289 }
290 }
291 vxfs_put_page(pp);
292 if (!rc)
293 break;
294 }
295
296 ctx->pos = pos | 2;
297
298out:
299 return 0;
300}