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Commit | Line | Data |
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1da177e4 LT |
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 | ||
18 | static int affs_readdir(struct file *, void *, filldir_t); | |
19 | ||
20 | struct file_operations affs_dir_operations = { | |
21 | .read = generic_read_dir, | |
22 | .readdir = affs_readdir, | |
23 | .fsync = file_fsync, | |
24 | }; | |
25 | ||
26 | /* | |
27 | * directories can handle most operations... | |
28 | */ | |
29 | struct inode_operations affs_dir_inode_operations = { | |
30 | .create = affs_create, | |
31 | .lookup = affs_lookup, | |
32 | .link = affs_link, | |
33 | .unlink = affs_unlink, | |
34 | .symlink = affs_symlink, | |
35 | .mkdir = affs_mkdir, | |
36 | .rmdir = affs_rmdir, | |
37 | .rename = affs_rename, | |
38 | .setattr = affs_notify_change, | |
39 | }; | |
40 | ||
41 | static int | |
42 | affs_readdir(struct file *filp, void *dirent, filldir_t filldir) | |
43 | { | |
44 | struct inode *inode = filp->f_dentry->d_inode; | |
45 | struct super_block *sb = inode->i_sb; | |
46 | struct buffer_head *dir_bh; | |
47 | struct buffer_head *fh_bh; | |
48 | unsigned char *name; | |
49 | int namelen; | |
50 | u32 i; | |
51 | int hash_pos; | |
52 | int chain_pos; | |
53 | u32 f_pos; | |
54 | u32 ino; | |
55 | int stored; | |
56 | int res; | |
57 | ||
58 | pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)\n",inode->i_ino,(unsigned long)filp->f_pos); | |
59 | ||
60 | stored = 0; | |
61 | res = -EIO; | |
62 | dir_bh = NULL; | |
63 | fh_bh = NULL; | |
64 | f_pos = filp->f_pos; | |
65 | ||
66 | if (f_pos == 0) { | |
67 | filp->private_data = (void *)0; | |
68 | if (filldir(dirent, ".", 1, f_pos, inode->i_ino, DT_DIR) < 0) | |
69 | return 0; | |
70 | filp->f_pos = f_pos = 1; | |
71 | stored++; | |
72 | } | |
73 | if (f_pos == 1) { | |
74 | if (filldir(dirent, "..", 2, f_pos, parent_ino(filp->f_dentry), DT_DIR) < 0) | |
75 | return stored; | |
76 | filp->f_pos = f_pos = 2; | |
77 | stored++; | |
78 | } | |
79 | ||
80 | affs_lock_dir(inode); | |
81 | chain_pos = (f_pos - 2) & 0xffff; | |
82 | hash_pos = (f_pos - 2) >> 16; | |
83 | if (chain_pos == 0xffff) { | |
84 | affs_warning(sb, "readdir", "More than 65535 entries in chain"); | |
85 | chain_pos = 0; | |
86 | hash_pos++; | |
87 | filp->f_pos = ((hash_pos << 16) | chain_pos) + 2; | |
88 | } | |
89 | dir_bh = affs_bread(sb, inode->i_ino); | |
90 | if (!dir_bh) | |
91 | goto readdir_out; | |
92 | ||
93 | /* If the directory hasn't changed since the last call to readdir(), | |
94 | * we can jump directly to where we left off. | |
95 | */ | |
96 | ino = (u32)(long)filp->private_data; | |
97 | if (ino && filp->f_version == inode->i_version) { | |
98 | pr_debug("AFFS: readdir() left off=%d\n", ino); | |
99 | goto inside; | |
100 | } | |
101 | ||
102 | ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]); | |
103 | for (i = 0; ino && i < chain_pos; i++) { | |
104 | fh_bh = affs_bread(sb, ino); | |
105 | if (!fh_bh) { | |
106 | affs_error(sb, "readdir","Cannot read block %d", i); | |
107 | goto readdir_out; | |
108 | } | |
109 | ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain); | |
110 | affs_brelse(fh_bh); | |
111 | fh_bh = NULL; | |
112 | } | |
113 | if (ino) | |
114 | goto inside; | |
115 | hash_pos++; | |
116 | ||
117 | for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) { | |
118 | ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]); | |
119 | if (!ino) | |
120 | continue; | |
121 | f_pos = (hash_pos << 16) + 2; | |
122 | inside: | |
123 | do { | |
124 | fh_bh = affs_bread(sb, ino); | |
125 | if (!fh_bh) { | |
126 | affs_error(sb, "readdir","Cannot read block %d", ino); | |
127 | goto readdir_done; | |
128 | } | |
129 | ||
130 | namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30); | |
131 | name = AFFS_TAIL(sb, fh_bh)->name + 1; | |
132 | pr_debug("AFFS: readdir(): filldir(\"%.*s\", ino=%u), hash=%d, f_pos=%x\n", | |
133 | namelen, name, ino, hash_pos, f_pos); | |
134 | if (filldir(dirent, name, namelen, f_pos, ino, DT_UNKNOWN) < 0) | |
135 | goto readdir_done; | |
136 | stored++; | |
137 | f_pos++; | |
138 | ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain); | |
139 | affs_brelse(fh_bh); | |
140 | fh_bh = NULL; | |
141 | } while (ino); | |
142 | } | |
143 | readdir_done: | |
144 | filp->f_pos = f_pos; | |
145 | filp->f_version = inode->i_version; | |
146 | filp->private_data = (void *)(long)ino; | |
147 | res = stored; | |
148 | ||
149 | readdir_out: | |
150 | affs_brelse(dir_bh); | |
151 | affs_brelse(fh_bh); | |
152 | affs_unlock_dir(inode); | |
153 | pr_debug("AFFS: readdir()=%d\n", stored); | |
154 | return res; | |
155 | } |