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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * dir.c
4 *
5 * PURPOSE
6 * Directory handling routines for the OSTA-UDF(tm) filesystem.
7 *
8 * COPYRIGHT
9 * (C) 1998-2004 Ben Fennema
10 *
11 * HISTORY
12 *
13 * 10/05/98 dgb Split directory operations into its own file
14 * Implemented directory reads via do_udf_readdir
15 * 10/06/98 Made directory operations work!
16 * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG
17 * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading
18 * across blocks.
19 * 12/12/98 Split out the lookup code to namei.c. bulk of directory
20 * code now in directory.c:udf_fileident_read.
21 */
22
23#include "udfdecl.h"
24
25#include <linux/string.h>
26#include <linux/errno.h>
27#include <linux/mm.h>
28#include <linux/slab.h>
29#include <linux/bio.h>
30#include <linux/iversion.h>
31
32#include "udf_i.h"
33#include "udf_sb.h"
34
35static int udf_readdir(struct file *file, struct dir_context *ctx)
36{
37 struct inode *dir = file_inode(file);
38 loff_t nf_pos, emit_pos = 0;
39 int flen;
40 unsigned char *fname = NULL;
41 int ret = 0;
42 struct super_block *sb = dir->i_sb;
43 bool pos_valid = false;
44 struct udf_fileident_iter iter;
45
46 if (ctx->pos == 0) {
47 if (!dir_emit_dot(file, ctx))
48 return 0;
49 ctx->pos = 1;
50 }
51 nf_pos = (ctx->pos - 1) << 2;
52 if (nf_pos >= dir->i_size)
53 goto out;
54
55 /*
56 * Something changed since last readdir (either lseek was called or dir
57 * changed)? We need to verify the position correctly points at the
58 * beginning of some dir entry so that the directory parsing code does
59 * not get confused. Since UDF does not have any reliable way of
60 * identifying beginning of dir entry (names are under user control),
61 * we need to scan the directory from the beginning.
62 */
63 if (!inode_eq_iversion(dir, *(u64 *)file->private_data)) {
64 emit_pos = nf_pos;
65 nf_pos = 0;
66 } else {
67 pos_valid = true;
68 }
69
70 fname = kmalloc(UDF_NAME_LEN, GFP_KERNEL);
71 if (!fname) {
72 ret = -ENOMEM;
73 goto out;
74 }
75
76 for (ret = udf_fiiter_init(&iter, dir, nf_pos);
77 !ret && iter.pos < dir->i_size;
78 ret = udf_fiiter_advance(&iter)) {
79 struct kernel_lb_addr tloc;
80 udf_pblk_t iblock;
81
82 /* Still not at offset where user asked us to read from? */
83 if (iter.pos < emit_pos)
84 continue;
85
86 /* Update file position only if we got past the current one */
87 pos_valid = true;
88 ctx->pos = (iter.pos >> 2) + 1;
89
90 if (iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
91 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
92 continue;
93 }
94
95 if (iter.fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) {
96 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
97 continue;
98 }
99
100 if (iter.fi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
101 if (!dir_emit_dotdot(file, ctx))
102 goto out_iter;
103 continue;
104 }
105
106 flen = udf_get_filename(sb, iter.name,
107 iter.fi.lengthFileIdent, fname, UDF_NAME_LEN);
108 if (flen < 0)
109 continue;
110
111 tloc = lelb_to_cpu(iter.fi.icb.extLocation);
112 iblock = udf_get_lb_pblock(sb, &tloc, 0);
113 if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN))
114 goto out_iter;
115 }
116
117 if (!ret) {
118 ctx->pos = (iter.pos >> 2) + 1;
119 pos_valid = true;
120 }
121out_iter:
122 udf_fiiter_release(&iter);
123out:
124 if (pos_valid)
125 *(u64 *)file->private_data = inode_query_iversion(dir);
126 kfree(fname);
127
128 return ret;
129}
130
131static int udf_dir_open(struct inode *inode, struct file *file)
132{
133 file->private_data = kzalloc(sizeof(u64), GFP_KERNEL);
134 if (!file->private_data)
135 return -ENOMEM;
136 return 0;
137}
138
139static int udf_dir_release(struct inode *inode, struct file *file)
140{
141 kfree(file->private_data);
142 return 0;
143}
144
145static loff_t udf_dir_llseek(struct file *file, loff_t offset, int whence)
146{
147 return generic_llseek_cookie(file, offset, whence,
148 (u64 *)file->private_data);
149}
150
151/* readdir and lookup functions */
152const struct file_operations udf_dir_operations = {
153 .open = udf_dir_open,
154 .release = udf_dir_release,
155 .llseek = udf_dir_llseek,
156 .read = generic_read_dir,
157 .iterate_shared = udf_readdir,
158 .unlocked_ioctl = udf_ioctl,
159 .fsync = generic_file_fsync,
160};
1/*
2 * dir.c
3 *
4 * PURPOSE
5 * Directory handling routines for the OSTA-UDF(tm) filesystem.
6 *
7 * COPYRIGHT
8 * This file is distributed under the terms of the GNU General Public
9 * License (GPL). Copies of the GPL can be obtained from:
10 * ftp://prep.ai.mit.edu/pub/gnu/GPL
11 * Each contributing author retains all rights to their own work.
12 *
13 * (C) 1998-2004 Ben Fennema
14 *
15 * HISTORY
16 *
17 * 10/05/98 dgb Split directory operations into its own file
18 * Implemented directory reads via do_udf_readdir
19 * 10/06/98 Made directory operations work!
20 * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG
21 * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading
22 * across blocks.
23 * 12/12/98 Split out the lookup code to namei.c. bulk of directory
24 * code now in directory.c:udf_fileident_read.
25 */
26
27#include "udfdecl.h"
28
29#include <linux/string.h>
30#include <linux/errno.h>
31#include <linux/mm.h>
32#include <linux/slab.h>
33#include <linux/bio.h>
34
35#include "udf_i.h"
36#include "udf_sb.h"
37
38
39static int udf_readdir(struct file *file, struct dir_context *ctx)
40{
41 struct inode *dir = file_inode(file);
42 struct udf_inode_info *iinfo = UDF_I(dir);
43 struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
44 struct fileIdentDesc *fi = NULL;
45 struct fileIdentDesc cfi;
46 udf_pblk_t block, iblock;
47 loff_t nf_pos;
48 int flen;
49 unsigned char *fname = NULL, *copy_name = NULL;
50 unsigned char *nameptr;
51 uint16_t liu;
52 uint8_t lfi;
53 loff_t size = udf_ext0_offset(dir) + dir->i_size;
54 struct buffer_head *tmp, *bha[16];
55 struct kernel_lb_addr eloc;
56 uint32_t elen;
57 sector_t offset;
58 int i, num, ret = 0;
59 struct extent_position epos = { NULL, 0, {0, 0} };
60 struct super_block *sb = dir->i_sb;
61
62 if (ctx->pos == 0) {
63 if (!dir_emit_dot(file, ctx))
64 return 0;
65 ctx->pos = 1;
66 }
67 nf_pos = (ctx->pos - 1) << 2;
68 if (nf_pos >= size)
69 goto out;
70
71 fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
72 if (!fname) {
73 ret = -ENOMEM;
74 goto out;
75 }
76
77 if (nf_pos == 0)
78 nf_pos = udf_ext0_offset(dir);
79
80 fibh.soffset = fibh.eoffset = nf_pos & (sb->s_blocksize - 1);
81 if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
82 if (inode_bmap(dir, nf_pos >> sb->s_blocksize_bits,
83 &epos, &eloc, &elen, &offset)
84 != (EXT_RECORDED_ALLOCATED >> 30)) {
85 ret = -ENOENT;
86 goto out;
87 }
88 block = udf_get_lb_pblock(sb, &eloc, offset);
89 if ((++offset << sb->s_blocksize_bits) < elen) {
90 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
91 epos.offset -= sizeof(struct short_ad);
92 else if (iinfo->i_alloc_type ==
93 ICBTAG_FLAG_AD_LONG)
94 epos.offset -= sizeof(struct long_ad);
95 } else {
96 offset = 0;
97 }
98
99 if (!(fibh.sbh = fibh.ebh = udf_tread(sb, block))) {
100 ret = -EIO;
101 goto out;
102 }
103
104 if (!(offset & ((16 >> (sb->s_blocksize_bits - 9)) - 1))) {
105 i = 16 >> (sb->s_blocksize_bits - 9);
106 if (i + offset > (elen >> sb->s_blocksize_bits))
107 i = (elen >> sb->s_blocksize_bits) - offset;
108 for (num = 0; i > 0; i--) {
109 block = udf_get_lb_pblock(sb, &eloc, offset + i);
110 tmp = udf_tgetblk(sb, block);
111 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
112 bha[num++] = tmp;
113 else
114 brelse(tmp);
115 }
116 if (num) {
117 ll_rw_block(REQ_OP_READ, REQ_RAHEAD, num, bha);
118 for (i = 0; i < num; i++)
119 brelse(bha[i]);
120 }
121 }
122 }
123
124 while (nf_pos < size) {
125 struct kernel_lb_addr tloc;
126
127 ctx->pos = (nf_pos >> 2) + 1;
128
129 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
130 &elen, &offset);
131 if (!fi)
132 goto out;
133
134 liu = le16_to_cpu(cfi.lengthOfImpUse);
135 lfi = cfi.lengthFileIdent;
136
137 if (fibh.sbh == fibh.ebh) {
138 nameptr = fi->fileIdent + liu;
139 } else {
140 int poffset; /* Unpaded ending offset */
141
142 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
143
144 if (poffset >= lfi) {
145 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
146 } else {
147 if (!copy_name) {
148 copy_name = kmalloc(UDF_NAME_LEN,
149 GFP_NOFS);
150 if (!copy_name) {
151 ret = -ENOMEM;
152 goto out;
153 }
154 }
155 nameptr = copy_name;
156 memcpy(nameptr, fi->fileIdent + liu,
157 lfi - poffset);
158 memcpy(nameptr + lfi - poffset,
159 fibh.ebh->b_data, poffset);
160 }
161 }
162
163 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
164 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
165 continue;
166 }
167
168 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
169 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
170 continue;
171 }
172
173 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
174 if (!dir_emit_dotdot(file, ctx))
175 goto out;
176 continue;
177 }
178
179 flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN);
180 if (flen < 0)
181 continue;
182
183 tloc = lelb_to_cpu(cfi.icb.extLocation);
184 iblock = udf_get_lb_pblock(sb, &tloc, 0);
185 if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN))
186 goto out;
187 } /* end while */
188
189 ctx->pos = (nf_pos >> 2) + 1;
190
191out:
192 if (fibh.sbh != fibh.ebh)
193 brelse(fibh.ebh);
194 brelse(fibh.sbh);
195 brelse(epos.bh);
196 kfree(fname);
197 kfree(copy_name);
198
199 return ret;
200}
201
202/* readdir and lookup functions */
203const struct file_operations udf_dir_operations = {
204 .llseek = generic_file_llseek,
205 .read = generic_read_dir,
206 .iterate_shared = udf_readdir,
207 .unlocked_ioctl = udf_ioctl,
208 .fsync = generic_file_fsync,
209};