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1/*
2 * linux/fs/affs/dir.c
3 *
4 * (c) 1996 Hans-Joachim Widmaier - Rewritten
5 *
6 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
7 *
8 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
9 *
10 * (C) 1991 Linus Torvalds - minix filesystem
11 *
12 * affs directory handling functions
13 *
14 */
15
16#include "affs.h"
17
18static int affs_readdir(struct file *, void *, filldir_t);
19
20const struct file_operations affs_dir_operations = {
21 .read = generic_read_dir,
22 .llseek = generic_file_llseek,
23 .readdir = affs_readdir,
24 .fsync = affs_file_fsync,
25};
26
27/*
28 * directories can handle most operations...
29 */
30const struct inode_operations affs_dir_inode_operations = {
31 .create = affs_create,
32 .lookup = affs_lookup,
33 .link = affs_link,
34 .unlink = affs_unlink,
35 .symlink = affs_symlink,
36 .mkdir = affs_mkdir,
37 .rmdir = affs_rmdir,
38 .rename = affs_rename,
39 .setattr = affs_notify_change,
40};
41
42static int
43affs_readdir(struct file *filp, void *dirent, filldir_t filldir)
44{
45 struct inode *inode = filp->f_path.dentry->d_inode;
46 struct super_block *sb = inode->i_sb;
47 struct buffer_head *dir_bh;
48 struct buffer_head *fh_bh;
49 unsigned char *name;
50 int namelen;
51 u32 i;
52 int hash_pos;
53 int chain_pos;
54 u32 f_pos;
55 u32 ino;
56 int stored;
57 int res;
58
59 pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)\n",inode->i_ino,(unsigned long)filp->f_pos);
60
61 stored = 0;
62 res = -EIO;
63 dir_bh = NULL;
64 fh_bh = NULL;
65 f_pos = filp->f_pos;
66
67 if (f_pos == 0) {
68 filp->private_data = (void *)0;
69 if (filldir(dirent, ".", 1, f_pos, inode->i_ino, DT_DIR) < 0)
70 return 0;
71 filp->f_pos = f_pos = 1;
72 stored++;
73 }
74 if (f_pos == 1) {
75 if (filldir(dirent, "..", 2, f_pos, parent_ino(filp->f_path.dentry), DT_DIR) < 0)
76 return stored;
77 filp->f_pos = f_pos = 2;
78 stored++;
79 }
80
81 affs_lock_dir(inode);
82 chain_pos = (f_pos - 2) & 0xffff;
83 hash_pos = (f_pos - 2) >> 16;
84 if (chain_pos == 0xffff) {
85 affs_warning(sb, "readdir", "More than 65535 entries in chain");
86 chain_pos = 0;
87 hash_pos++;
88 filp->f_pos = ((hash_pos << 16) | chain_pos) + 2;
89 }
90 dir_bh = affs_bread(sb, inode->i_ino);
91 if (!dir_bh)
92 goto readdir_out;
93
94 /* If the directory hasn't changed since the last call to readdir(),
95 * we can jump directly to where we left off.
96 */
97 ino = (u32)(long)filp->private_data;
98 if (ino && filp->f_version == inode->i_version) {
99 pr_debug("AFFS: readdir() left off=%d\n", ino);
100 goto inside;
101 }
102
103 ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
104 for (i = 0; ino && i < chain_pos; i++) {
105 fh_bh = affs_bread(sb, ino);
106 if (!fh_bh) {
107 affs_error(sb, "readdir","Cannot read block %d", i);
108 goto readdir_out;
109 }
110 ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
111 affs_brelse(fh_bh);
112 fh_bh = NULL;
113 }
114 if (ino)
115 goto inside;
116 hash_pos++;
117
118 for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
119 ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
120 if (!ino)
121 continue;
122 f_pos = (hash_pos << 16) + 2;
123inside:
124 do {
125 fh_bh = affs_bread(sb, ino);
126 if (!fh_bh) {
127 affs_error(sb, "readdir","Cannot read block %d", ino);
128 goto readdir_done;
129 }
130
131 namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30);
132 name = AFFS_TAIL(sb, fh_bh)->name + 1;
133 pr_debug("AFFS: readdir(): filldir(\"%.*s\", ino=%u), hash=%d, f_pos=%x\n",
134 namelen, name, ino, hash_pos, f_pos);
135 if (filldir(dirent, name, namelen, f_pos, ino, DT_UNKNOWN) < 0)
136 goto readdir_done;
137 stored++;
138 f_pos++;
139 ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
140 affs_brelse(fh_bh);
141 fh_bh = NULL;
142 } while (ino);
143 }
144readdir_done:
145 filp->f_pos = f_pos;
146 filp->f_version = inode->i_version;
147 filp->private_data = (void *)(long)ino;
148 res = stored;
149
150readdir_out:
151 affs_brelse(dir_bh);
152 affs_brelse(fh_bh);
153 affs_unlock_dir(inode);
154 pr_debug("AFFS: readdir()=%d\n", stored);
155 return res;
156}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/affs/dir.c
4 *
5 * (c) 1996 Hans-Joachim Widmaier - Rewritten
6 *
7 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
8 *
9 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
10 *
11 * (C) 1991 Linus Torvalds - minix filesystem
12 *
13 * affs directory handling functions
14 *
15 */
16
17#include <linux/iversion.h>
18#include "affs.h"
19
20struct affs_dir_data {
21 unsigned long ino;
22 u64 cookie;
23};
24
25static int affs_readdir(struct file *, struct dir_context *);
26
27static loff_t affs_dir_llseek(struct file *file, loff_t offset, int whence)
28{
29 struct affs_dir_data *data = file->private_data;
30
31 return generic_llseek_cookie(file, offset, whence, &data->cookie);
32}
33
34static int affs_dir_open(struct inode *inode, struct file *file)
35{
36 struct affs_dir_data *data;
37
38 data = kzalloc(sizeof(struct affs_dir_data), GFP_KERNEL);
39 if (!data)
40 return -ENOMEM;
41 file->private_data = data;
42 return 0;
43}
44
45static int affs_dir_release(struct inode *inode, struct file *file)
46{
47 kfree(file->private_data);
48 return 0;
49}
50
51const struct file_operations affs_dir_operations = {
52 .open = affs_dir_open,
53 .read = generic_read_dir,
54 .llseek = affs_dir_llseek,
55 .iterate_shared = affs_readdir,
56 .fsync = affs_file_fsync,
57 .release = affs_dir_release,
58};
59
60/*
61 * directories can handle most operations...
62 */
63const struct inode_operations affs_dir_inode_operations = {
64 .create = affs_create,
65 .lookup = affs_lookup,
66 .link = affs_link,
67 .unlink = affs_unlink,
68 .symlink = affs_symlink,
69 .mkdir = affs_mkdir,
70 .rmdir = affs_rmdir,
71 .rename = affs_rename2,
72 .setattr = affs_notify_change,
73};
74
75static int
76affs_readdir(struct file *file, struct dir_context *ctx)
77{
78 struct inode *inode = file_inode(file);
79 struct affs_dir_data *data = file->private_data;
80 struct super_block *sb = inode->i_sb;
81 struct buffer_head *dir_bh = NULL;
82 struct buffer_head *fh_bh = NULL;
83 unsigned char *name;
84 int namelen;
85 u32 i;
86 int hash_pos;
87 int chain_pos;
88 u32 ino;
89 int error = 0;
90
91 pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
92
93 if (ctx->pos < 2) {
94 data->ino = 0;
95 if (!dir_emit_dots(file, ctx))
96 return 0;
97 }
98
99 affs_lock_dir(inode);
100 chain_pos = (ctx->pos - 2) & 0xffff;
101 hash_pos = (ctx->pos - 2) >> 16;
102 if (chain_pos == 0xffff) {
103 affs_warning(sb, "readdir", "More than 65535 entries in chain");
104 chain_pos = 0;
105 hash_pos++;
106 ctx->pos = ((hash_pos << 16) | chain_pos) + 2;
107 }
108 dir_bh = affs_bread(sb, inode->i_ino);
109 if (!dir_bh)
110 goto out_unlock_dir;
111
112 /* If the directory hasn't changed since the last call to readdir(),
113 * we can jump directly to where we left off.
114 */
115 ino = data->ino;
116 if (ino && inode_eq_iversion(inode, data->cookie)) {
117 pr_debug("readdir() left off=%d\n", ino);
118 goto inside;
119 }
120
121 ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
122 for (i = 0; ino && i < chain_pos; i++) {
123 fh_bh = affs_bread(sb, ino);
124 if (!fh_bh) {
125 affs_error(sb, "readdir","Cannot read block %d", i);
126 error = -EIO;
127 goto out_brelse_dir;
128 }
129 ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
130 affs_brelse(fh_bh);
131 fh_bh = NULL;
132 }
133 if (ino)
134 goto inside;
135 hash_pos++;
136
137 for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
138 ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
139 if (!ino)
140 continue;
141 ctx->pos = (hash_pos << 16) + 2;
142inside:
143 do {
144 fh_bh = affs_bread(sb, ino);
145 if (!fh_bh) {
146 affs_error(sb, "readdir",
147 "Cannot read block %d", ino);
148 break;
149 }
150
151 namelen = min(AFFS_TAIL(sb, fh_bh)->name[0],
152 (u8)AFFSNAMEMAX);
153 name = AFFS_TAIL(sb, fh_bh)->name + 1;
154 pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n",
155 namelen, name, ino, hash_pos, ctx->pos);
156
157 if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
158 goto done;
159 ctx->pos++;
160 ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
161 affs_brelse(fh_bh);
162 fh_bh = NULL;
163 } while (ino);
164 }
165done:
166 data->cookie = inode_query_iversion(inode);
167 data->ino = ino;
168 affs_brelse(fh_bh);
169
170out_brelse_dir:
171 affs_brelse(dir_bh);
172
173out_unlock_dir:
174 affs_unlock_dir(inode);
175 return error;
176}