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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2000-2001 Christoph Hellwig.
4 * Copyright (c) 2016 Krzysztof Blaszkowski
5 */
6
7/*
8 * Veritas filesystem driver - lookup and other directory related code.
9 */
10#include <linux/fs.h>
11#include <linux/time.h>
12#include <linux/mm.h>
13#include <linux/highmem.h>
14#include <linux/kernel.h>
15#include <linux/pagemap.h>
16
17#include "vxfs.h"
18#include "vxfs_dir.h"
19#include "vxfs_inode.h"
20#include "vxfs_extern.h"
21
22/*
23 * Number of VxFS blocks per page.
24 */
25#define VXFS_BLOCK_PER_PAGE(sbp) ((PAGE_SIZE / (sbp)->s_blocksize))
26
27
28static struct dentry * vxfs_lookup(struct inode *, struct dentry *, unsigned int);
29static int vxfs_readdir(struct file *, struct dir_context *);
30
31const struct inode_operations vxfs_dir_inode_ops = {
32 .lookup = vxfs_lookup,
33};
34
35const struct file_operations vxfs_dir_operations = {
36 .llseek = generic_file_llseek,
37 .read = generic_read_dir,
38 .iterate_shared = vxfs_readdir,
39};
40
41
42/**
43 * vxfs_find_entry - find a mathing directory entry for a dentry
44 * @ip: directory inode
45 * @dp: dentry for which we want to find a direct
46 * @ppp: gets filled with the page the return value sits in
47 *
48 * Description:
49 * vxfs_find_entry finds a &struct vxfs_direct for the VFS directory
50 * cache entry @dp. @ppp will be filled with the page the return
51 * value resides in.
52 *
53 * Returns:
54 * The wanted direct on success, else a NULL pointer.
55 */
56static struct vxfs_direct *
57vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp)
58{
59 u_long bsize = ip->i_sb->s_blocksize;
60 const char *name = dp->d_name.name;
61 int namelen = dp->d_name.len;
62 loff_t limit = VXFS_DIRROUND(ip->i_size);
63 struct vxfs_direct *de_exit = NULL;
64 loff_t pos = 0;
65 struct vxfs_sb_info *sbi = VXFS_SBI(ip->i_sb);
66
67 while (pos < limit) {
68 struct page *pp;
69 char *kaddr;
70 int pg_ofs = pos & ~PAGE_MASK;
71
72 pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
73 if (IS_ERR(pp))
74 return NULL;
75 kaddr = (char *)page_address(pp);
76
77 while (pg_ofs < PAGE_SIZE && pos < limit) {
78 struct vxfs_direct *de;
79
80 if ((pos & (bsize - 1)) < 4) {
81 struct vxfs_dirblk *dbp =
82 (struct vxfs_dirblk *)
83 (kaddr + (pos & ~PAGE_MASK));
84 int overhead = VXFS_DIRBLKOV(sbi, dbp);
85
86 pos += overhead;
87 pg_ofs += overhead;
88 }
89 de = (struct vxfs_direct *)(kaddr + pg_ofs);
90
91 if (!de->d_reclen) {
92 pos += bsize - 1;
93 pos &= ~(bsize - 1);
94 break;
95 }
96
97 pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
98 pos += fs16_to_cpu(sbi, de->d_reclen);
99 if (!de->d_ino)
100 continue;
101
102 if (namelen != fs16_to_cpu(sbi, de->d_namelen))
103 continue;
104 if (!memcmp(name, de->d_name, namelen)) {
105 *ppp = pp;
106 de_exit = de;
107 break;
108 }
109 }
110 if (!de_exit)
111 vxfs_put_page(pp);
112 else
113 break;
114 }
115
116 return de_exit;
117}
118
119/**
120 * vxfs_inode_by_name - find inode number for dentry
121 * @dip: directory to search in
122 * @dp: dentry we search for
123 *
124 * Description:
125 * vxfs_inode_by_name finds out the inode number of
126 * the path component described by @dp in @dip.
127 *
128 * Returns:
129 * The wanted inode number on success, else Zero.
130 */
131static ino_t
132vxfs_inode_by_name(struct inode *dip, struct dentry *dp)
133{
134 struct vxfs_direct *de;
135 struct page *pp;
136 ino_t ino = 0;
137
138 de = vxfs_find_entry(dip, dp, &pp);
139 if (de) {
140 ino = fs32_to_cpu(VXFS_SBI(dip->i_sb), de->d_ino);
141 kunmap(pp);
142 put_page(pp);
143 }
144
145 return (ino);
146}
147
148/**
149 * vxfs_lookup - lookup pathname component
150 * @dip: dir in which we lookup
151 * @dp: dentry we lookup
152 * @flags: lookup flags
153 *
154 * Description:
155 * vxfs_lookup tries to lookup the pathname component described
156 * by @dp in @dip.
157 *
158 * Returns:
159 * A NULL-pointer on success, else a negative error code encoded
160 * in the return pointer.
161 */
162static struct dentry *
163vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags)
164{
165 struct inode *ip = NULL;
166 ino_t ino;
167
168 if (dp->d_name.len > VXFS_NAMELEN)
169 return ERR_PTR(-ENAMETOOLONG);
170
171 ino = vxfs_inode_by_name(dip, dp);
172 if (ino)
173 ip = vxfs_iget(dip->i_sb, ino);
174 return d_splice_alias(ip, dp);
175}
176
177/**
178 * vxfs_readdir - read a directory
179 * @fp: the directory to read
180 * @ctx: dir_context for filldir/readdir
181 *
182 * Description:
183 * vxfs_readdir fills @retp with directory entries from @fp
184 * using the VFS supplied callback @filler.
185 *
186 * Returns:
187 * Zero.
188 */
189static int
190vxfs_readdir(struct file *fp, struct dir_context *ctx)
191{
192 struct inode *ip = file_inode(fp);
193 struct super_block *sbp = ip->i_sb;
194 u_long bsize = sbp->s_blocksize;
195 loff_t pos, limit;
196 struct vxfs_sb_info *sbi = VXFS_SBI(sbp);
197
198 if (ctx->pos == 0) {
199 if (!dir_emit_dot(fp, ctx))
200 goto out;
201 ctx->pos++;
202 }
203 if (ctx->pos == 1) {
204 if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
205 goto out;
206 ctx->pos++;
207 }
208
209 limit = VXFS_DIRROUND(ip->i_size);
210 if (ctx->pos > limit)
211 goto out;
212
213 pos = ctx->pos & ~3L;
214
215 while (pos < limit) {
216 struct page *pp;
217 char *kaddr;
218 int pg_ofs = pos & ~PAGE_MASK;
219 int rc = 0;
220
221 pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
222 if (IS_ERR(pp))
223 return -ENOMEM;
224
225 kaddr = (char *)page_address(pp);
226
227 while (pg_ofs < PAGE_SIZE && pos < limit) {
228 struct vxfs_direct *de;
229
230 if ((pos & (bsize - 1)) < 4) {
231 struct vxfs_dirblk *dbp =
232 (struct vxfs_dirblk *)
233 (kaddr + (pos & ~PAGE_MASK));
234 int overhead = VXFS_DIRBLKOV(sbi, dbp);
235
236 pos += overhead;
237 pg_ofs += overhead;
238 }
239 de = (struct vxfs_direct *)(kaddr + pg_ofs);
240
241 if (!de->d_reclen) {
242 pos += bsize - 1;
243 pos &= ~(bsize - 1);
244 break;
245 }
246
247 pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
248 pos += fs16_to_cpu(sbi, de->d_reclen);
249 if (!de->d_ino)
250 continue;
251
252 rc = dir_emit(ctx, de->d_name,
253 fs16_to_cpu(sbi, de->d_namelen),
254 fs32_to_cpu(sbi, de->d_ino),
255 DT_UNKNOWN);
256 if (!rc) {
257 /* the dir entry was not read, fix pos. */
258 pos -= fs16_to_cpu(sbi, de->d_reclen);
259 break;
260 }
261 }
262 vxfs_put_page(pp);
263 if (!rc)
264 break;
265 }
266
267 ctx->pos = pos | 2;
268
269out:
270 return 0;
271}
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_SIZE / (sbp)->s_blocksize))
49
50
51static struct dentry * vxfs_lookup(struct inode *, struct dentry *, unsigned int);
52static int vxfs_readdir(struct file *, struct dir_context *);
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 .iterate = vxfs_readdir,
62};
63
64static inline u_long
65dir_blocks(struct inode *ip)
66{
67 u_long bsize = ip->i_sb->s_blocksize;
68 return (ip->i_size + bsize - 1) & ~(bsize - 1);
69}
70
71/*
72 * NOTE! unlike strncmp, vxfs_match returns 1 for success, 0 for failure.
73 *
74 * len <= VXFS_NAMELEN and de != NULL are guaranteed by caller.
75 */
76static inline int
77vxfs_match(int len, const char * const name, struct vxfs_direct *de)
78{
79 if (len != de->d_namelen)
80 return 0;
81 if (!de->d_ino)
82 return 0;
83 return !memcmp(name, de->d_name, len);
84}
85
86static inline struct vxfs_direct *
87vxfs_next_entry(struct vxfs_direct *de)
88{
89 return ((struct vxfs_direct *)((char*)de + de->d_reclen));
90}
91
92/**
93 * vxfs_find_entry - find a mathing directory entry for a dentry
94 * @ip: directory inode
95 * @dp: dentry for which we want to find a direct
96 * @ppp: gets filled with the page the return value sits in
97 *
98 * Description:
99 * vxfs_find_entry finds a &struct vxfs_direct for the VFS directory
100 * cache entry @dp. @ppp will be filled with the page the return
101 * value resides in.
102 *
103 * Returns:
104 * The wanted direct on success, else a NULL pointer.
105 */
106static struct vxfs_direct *
107vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp)
108{
109 u_long npages, page, nblocks, pblocks, block;
110 u_long bsize = ip->i_sb->s_blocksize;
111 const char *name = dp->d_name.name;
112 int namelen = dp->d_name.len;
113
114 npages = dir_pages(ip);
115 nblocks = dir_blocks(ip);
116 pblocks = VXFS_BLOCK_PER_PAGE(ip->i_sb);
117
118 for (page = 0; page < npages; page++) {
119 caddr_t kaddr;
120 struct page *pp;
121
122 pp = vxfs_get_page(ip->i_mapping, page);
123 if (IS_ERR(pp))
124 continue;
125 kaddr = (caddr_t)page_address(pp);
126
127 for (block = 0; block <= nblocks && block <= pblocks; block++) {
128 caddr_t baddr, limit;
129 struct vxfs_dirblk *dbp;
130 struct vxfs_direct *de;
131
132 baddr = kaddr + (block * bsize);
133 limit = baddr + bsize - VXFS_DIRLEN(1);
134
135 dbp = (struct vxfs_dirblk *)baddr;
136 de = (struct vxfs_direct *)(baddr + VXFS_DIRBLKOV(dbp));
137
138 for (; (caddr_t)de <= limit; de = vxfs_next_entry(de)) {
139 if (!de->d_reclen)
140 break;
141 if (!de->d_ino)
142 continue;
143 if (vxfs_match(namelen, name, de)) {
144 *ppp = pp;
145 return (de);
146 }
147 }
148 }
149 vxfs_put_page(pp);
150 }
151
152 return NULL;
153}
154
155/**
156 * vxfs_inode_by_name - find inode number for dentry
157 * @dip: directory to search in
158 * @dp: dentry we search for
159 *
160 * Description:
161 * vxfs_inode_by_name finds out the inode number of
162 * the path component described by @dp in @dip.
163 *
164 * Returns:
165 * The wanted inode number on success, else Zero.
166 */
167static ino_t
168vxfs_inode_by_name(struct inode *dip, struct dentry *dp)
169{
170 struct vxfs_direct *de;
171 struct page *pp;
172 ino_t ino = 0;
173
174 de = vxfs_find_entry(dip, dp, &pp);
175 if (de) {
176 ino = de->d_ino;
177 kunmap(pp);
178 put_page(pp);
179 }
180
181 return (ino);
182}
183
184/**
185 * vxfs_lookup - lookup pathname component
186 * @dip: dir in which we lookup
187 * @dp: dentry we lookup
188 * @flags: lookup flags
189 *
190 * Description:
191 * vxfs_lookup tries to lookup the pathname component described
192 * by @dp in @dip.
193 *
194 * Returns:
195 * A NULL-pointer on success, else a negative error code encoded
196 * in the return pointer.
197 */
198static struct dentry *
199vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags)
200{
201 struct inode *ip = NULL;
202 ino_t ino;
203
204 if (dp->d_name.len > VXFS_NAMELEN)
205 return ERR_PTR(-ENAMETOOLONG);
206
207 ino = vxfs_inode_by_name(dip, dp);
208 if (ino) {
209 ip = vxfs_iget(dip->i_sb, ino);
210 if (IS_ERR(ip))
211 return ERR_CAST(ip);
212 }
213 d_add(dp, ip);
214 return NULL;
215}
216
217/**
218 * vxfs_readdir - read a directory
219 * @fp: the directory to read
220 * @retp: return buffer
221 * @filler: filldir callback
222 *
223 * Description:
224 * vxfs_readdir fills @retp with directory entries from @fp
225 * using the VFS supplied callback @filler.
226 *
227 * Returns:
228 * Zero.
229 */
230static int
231vxfs_readdir(struct file *fp, struct dir_context *ctx)
232{
233 struct inode *ip = file_inode(fp);
234 struct super_block *sbp = ip->i_sb;
235 u_long bsize = sbp->s_blocksize;
236 u_long page, npages, block, pblocks, nblocks, offset;
237 loff_t pos;
238
239 if (ctx->pos == 0) {
240 if (!dir_emit_dot(fp, ctx))
241 return 0;
242 ctx->pos = 1;
243 }
244 if (ctx->pos == 1) {
245 if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
246 return 0;
247 ctx->pos = 2;
248 }
249 pos = ctx->pos - 2;
250
251 if (pos > VXFS_DIRROUND(ip->i_size))
252 return 0;
253
254 npages = dir_pages(ip);
255 nblocks = dir_blocks(ip);
256 pblocks = VXFS_BLOCK_PER_PAGE(sbp);
257
258 page = pos >> PAGE_SHIFT;
259 offset = pos & ~PAGE_MASK;
260 block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks;
261
262 for (; page < npages; page++, block = 0) {
263 char *kaddr;
264 struct page *pp;
265
266 pp = vxfs_get_page(ip->i_mapping, page);
267 if (IS_ERR(pp))
268 continue;
269 kaddr = (char *)page_address(pp);
270
271 for (; block <= nblocks && block <= pblocks; block++) {
272 char *baddr, *limit;
273 struct vxfs_dirblk *dbp;
274 struct vxfs_direct *de;
275
276 baddr = kaddr + (block * bsize);
277 limit = baddr + bsize - VXFS_DIRLEN(1);
278
279 dbp = (struct vxfs_dirblk *)baddr;
280 de = (struct vxfs_direct *)
281 (offset ?
282 (kaddr + offset) :
283 (baddr + VXFS_DIRBLKOV(dbp)));
284
285 for (; (char *)de <= limit; de = vxfs_next_entry(de)) {
286 if (!de->d_reclen)
287 break;
288 if (!de->d_ino)
289 continue;
290
291 offset = (char *)de - kaddr;
292 ctx->pos = ((page << PAGE_SHIFT) | offset) + 2;
293 if (!dir_emit(ctx, de->d_name, de->d_namelen,
294 de->d_ino, DT_UNKNOWN)) {
295 vxfs_put_page(pp);
296 return 0;
297 }
298 }
299 offset = 0;
300 }
301 vxfs_put_page(pp);
302 offset = 0;
303 }
304 ctx->pos = ((page << PAGE_SHIFT) | offset) + 2;
305 return 0;
306}