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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 *, struct dir_context *);
19
20const struct file_operations affs_dir_operations = {
21 .read = generic_read_dir,
22 .llseek = generic_file_llseek,
23 .iterate = 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 *file, struct dir_context *ctx)
44{
45 struct inode *inode = file_inode(file);
46 struct super_block *sb = inode->i_sb;
47 struct buffer_head *dir_bh = NULL;
48 struct buffer_head *fh_bh = NULL;
49 unsigned char *name;
50 int namelen;
51 u32 i;
52 int hash_pos;
53 int chain_pos;
54 u32 ino;
55 int error = 0;
56
57 pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
58
59 if (ctx->pos < 2) {
60 file->private_data = (void *)0;
61 if (!dir_emit_dots(file, ctx))
62 return 0;
63 }
64
65 affs_lock_dir(inode);
66 chain_pos = (ctx->pos - 2) & 0xffff;
67 hash_pos = (ctx->pos - 2) >> 16;
68 if (chain_pos == 0xffff) {
69 affs_warning(sb, "readdir", "More than 65535 entries in chain");
70 chain_pos = 0;
71 hash_pos++;
72 ctx->pos = ((hash_pos << 16) | chain_pos) + 2;
73 }
74 dir_bh = affs_bread(sb, inode->i_ino);
75 if (!dir_bh)
76 goto out_unlock_dir;
77
78 /* If the directory hasn't changed since the last call to readdir(),
79 * we can jump directly to where we left off.
80 */
81 ino = (u32)(long)file->private_data;
82 if (ino && file->f_version == inode->i_version) {
83 pr_debug("readdir() left off=%d\n", ino);
84 goto inside;
85 }
86
87 ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
88 for (i = 0; ino && i < chain_pos; i++) {
89 fh_bh = affs_bread(sb, ino);
90 if (!fh_bh) {
91 affs_error(sb, "readdir","Cannot read block %d", i);
92 error = -EIO;
93 goto out_brelse_dir;
94 }
95 ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
96 affs_brelse(fh_bh);
97 fh_bh = NULL;
98 }
99 if (ino)
100 goto inside;
101 hash_pos++;
102
103 for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
104 ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
105 if (!ino)
106 continue;
107 ctx->pos = (hash_pos << 16) + 2;
108inside:
109 do {
110 fh_bh = affs_bread(sb, ino);
111 if (!fh_bh) {
112 affs_error(sb, "readdir",
113 "Cannot read block %d", ino);
114 break;
115 }
116
117 namelen = min(AFFS_TAIL(sb, fh_bh)->name[0],
118 (u8)AFFSNAMEMAX);
119 name = AFFS_TAIL(sb, fh_bh)->name + 1;
120 pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n",
121 namelen, name, ino, hash_pos, ctx->pos);
122
123 if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
124 goto done;
125 ctx->pos++;
126 ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
127 affs_brelse(fh_bh);
128 fh_bh = NULL;
129 } while (ino);
130 }
131done:
132 file->f_version = inode->i_version;
133 file->private_data = (void *)(long)ino;
134 affs_brelse(fh_bh);
135
136out_brelse_dir:
137 affs_brelse(dir_bh);
138
139out_unlock_dir:
140 affs_unlock_dir(inode);
141 return error;
142}
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
20static int affs_readdir(struct file *, struct dir_context *);
21
22const struct file_operations affs_dir_operations = {
23 .read = generic_read_dir,
24 .llseek = generic_file_llseek,
25 .iterate_shared = affs_readdir,
26 .fsync = affs_file_fsync,
27};
28
29/*
30 * directories can handle most operations...
31 */
32const struct inode_operations affs_dir_inode_operations = {
33 .create = affs_create,
34 .lookup = affs_lookup,
35 .link = affs_link,
36 .unlink = affs_unlink,
37 .symlink = affs_symlink,
38 .mkdir = affs_mkdir,
39 .rmdir = affs_rmdir,
40 .rename = affs_rename2,
41 .setattr = affs_notify_change,
42};
43
44static int
45affs_readdir(struct file *file, struct dir_context *ctx)
46{
47 struct inode *inode = file_inode(file);
48 struct super_block *sb = inode->i_sb;
49 struct buffer_head *dir_bh = NULL;
50 struct buffer_head *fh_bh = NULL;
51 unsigned char *name;
52 int namelen;
53 u32 i;
54 int hash_pos;
55 int chain_pos;
56 u32 ino;
57 int error = 0;
58
59 pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
60
61 if (ctx->pos < 2) {
62 file->private_data = (void *)0;
63 if (!dir_emit_dots(file, ctx))
64 return 0;
65 }
66
67 affs_lock_dir(inode);
68 chain_pos = (ctx->pos - 2) & 0xffff;
69 hash_pos = (ctx->pos - 2) >> 16;
70 if (chain_pos == 0xffff) {
71 affs_warning(sb, "readdir", "More than 65535 entries in chain");
72 chain_pos = 0;
73 hash_pos++;
74 ctx->pos = ((hash_pos << 16) | chain_pos) + 2;
75 }
76 dir_bh = affs_bread(sb, inode->i_ino);
77 if (!dir_bh)
78 goto out_unlock_dir;
79
80 /* If the directory hasn't changed since the last call to readdir(),
81 * we can jump directly to where we left off.
82 */
83 ino = (u32)(long)file->private_data;
84 if (ino && inode_eq_iversion(inode, file->f_version)) {
85 pr_debug("readdir() left off=%d\n", ino);
86 goto inside;
87 }
88
89 ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
90 for (i = 0; ino && i < chain_pos; i++) {
91 fh_bh = affs_bread(sb, ino);
92 if (!fh_bh) {
93 affs_error(sb, "readdir","Cannot read block %d", i);
94 error = -EIO;
95 goto out_brelse_dir;
96 }
97 ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
98 affs_brelse(fh_bh);
99 fh_bh = NULL;
100 }
101 if (ino)
102 goto inside;
103 hash_pos++;
104
105 for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
106 ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
107 if (!ino)
108 continue;
109 ctx->pos = (hash_pos << 16) + 2;
110inside:
111 do {
112 fh_bh = affs_bread(sb, ino);
113 if (!fh_bh) {
114 affs_error(sb, "readdir",
115 "Cannot read block %d", ino);
116 break;
117 }
118
119 namelen = min(AFFS_TAIL(sb, fh_bh)->name[0],
120 (u8)AFFSNAMEMAX);
121 name = AFFS_TAIL(sb, fh_bh)->name + 1;
122 pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n",
123 namelen, name, ino, hash_pos, ctx->pos);
124
125 if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
126 goto done;
127 ctx->pos++;
128 ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
129 affs_brelse(fh_bh);
130 fh_bh = NULL;
131 } while (ino);
132 }
133done:
134 file->f_version = inode_query_iversion(inode);
135 file->private_data = (void *)(long)ino;
136 affs_brelse(fh_bh);
137
138out_brelse_dir:
139 affs_brelse(dir_bh);
140
141out_unlock_dir:
142 affs_unlock_dir(inode);
143 return error;
144}