Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * dir.c | |
3 | * | |
4 | * PURPOSE | |
5 | * Directory handling routines for the OSTA-UDF(tm) filesystem. | |
6 | * | |
1da177e4 LT |
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> | |
2f8b5444 | 33 | #include <linux/bio.h> |
a48fc69f | 34 | #include <linux/iversion.h> |
1da177e4 LT |
35 | |
36 | #include "udf_i.h" | |
37 | #include "udf_sb.h" | |
38 | ||
5add2ee1 | 39 | static int udf_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 40 | { |
5add2ee1 | 41 | struct inode *dir = file_inode(file); |
a48fc69f | 42 | loff_t nf_pos, emit_pos = 0; |
1da177e4 | 43 | int flen; |
7cd7a36a JK |
44 | unsigned char *fname = NULL; |
45 | int ret = 0; | |
3ee3039c | 46 | struct super_block *sb = dir->i_sb; |
a48fc69f | 47 | bool pos_valid = false; |
7cd7a36a | 48 | struct udf_fileident_iter iter; |
1da177e4 | 49 | |
5add2ee1 AV |
50 | if (ctx->pos == 0) { |
51 | if (!dir_emit_dot(file, ctx)) | |
52 | return 0; | |
53 | ctx->pos = 1; | |
54 | } | |
55 | nf_pos = (ctx->pos - 1) << 2; | |
7cd7a36a | 56 | if (nf_pos >= dir->i_size) |
b80697c1 JK |
57 | goto out; |
58 | ||
a48fc69f JK |
59 | /* |
60 | * Something changed since last readdir (either lseek was called or dir | |
61 | * changed)? We need to verify the position correctly points at the | |
62 | * beginning of some dir entry so that the directory parsing code does | |
63 | * not get confused. Since UDF does not have any reliable way of | |
64 | * identifying beginning of dir entry (names are under user control), | |
65 | * we need to scan the directory from the beginning. | |
66 | */ | |
67 | if (!inode_eq_iversion(dir, file->f_version)) { | |
68 | emit_pos = nf_pos; | |
69 | nf_pos = 0; | |
70 | } else { | |
71 | pos_valid = true; | |
72 | } | |
73 | ||
b80697c1 JK |
74 | fname = kmalloc(UDF_NAME_LEN, GFP_NOFS); |
75 | if (!fname) { | |
76 | ret = -ENOMEM; | |
77 | goto out; | |
78 | } | |
1da177e4 | 79 | |
7cd7a36a JK |
80 | for (ret = udf_fiiter_init(&iter, dir, nf_pos); |
81 | !ret && iter.pos < dir->i_size; | |
82 | ret = udf_fiiter_advance(&iter)) { | |
5add2ee1 | 83 | struct kernel_lb_addr tloc; |
7cd7a36a | 84 | udf_pblk_t iblock; |
5add2ee1 | 85 | |
a48fc69f | 86 | /* Still not at offset where user asked us to read from? */ |
7cd7a36a | 87 | if (iter.pos < emit_pos) |
a48fc69f | 88 | continue; |
1da177e4 | 89 | |
7cd7a36a JK |
90 | /* Update file position only if we got past the current one */ |
91 | pos_valid = true; | |
92 | ctx->pos = (iter.pos >> 2) + 1; | |
1da177e4 | 93 | |
7cd7a36a | 94 | if (iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED) { |
3ee3039c | 95 | if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE)) |
1da177e4 LT |
96 | continue; |
97 | } | |
cb00ea35 | 98 | |
7cd7a36a | 99 | if (iter.fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) { |
3ee3039c | 100 | if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE)) |
1da177e4 LT |
101 | continue; |
102 | } | |
103 | ||
7cd7a36a | 104 | if (iter.fi.fileCharacteristics & FID_FILE_CHAR_PARENT) { |
5add2ee1 | 105 | if (!dir_emit_dotdot(file, ctx)) |
7cd7a36a | 106 | goto out_iter; |
5add2ee1 | 107 | continue; |
1da177e4 LT |
108 | } |
109 | ||
7cd7a36a JK |
110 | flen = udf_get_filename(sb, iter.name, |
111 | iter.fi.lengthFileIdent, fname, UDF_NAME_LEN); | |
6ce63836 | 112 | if (flen < 0) |
5add2ee1 AV |
113 | continue; |
114 | ||
7cd7a36a | 115 | tloc = lelb_to_cpu(iter.fi.icb.extLocation); |
3ee3039c | 116 | iblock = udf_get_lb_pblock(sb, &tloc, 0); |
5add2ee1 | 117 | if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN)) |
7cd7a36a JK |
118 | goto out_iter; |
119 | } | |
1da177e4 | 120 | |
7cd7a36a JK |
121 | if (!ret) { |
122 | ctx->pos = (iter.pos >> 2) + 1; | |
123 | pos_valid = true; | |
124 | } | |
125 | out_iter: | |
126 | udf_fiiter_release(&iter); | |
b80697c1 | 127 | out: |
a48fc69f JK |
128 | if (pos_valid) |
129 | file->f_version = inode_query_iversion(dir); | |
b80697c1 | 130 | kfree(fname); |
1da177e4 | 131 | |
b80697c1 | 132 | return ret; |
1da177e4 | 133 | } |
934c5e60 | 134 | |
934c5e60 MS |
135 | /* readdir and lookup functions */ |
136 | const struct file_operations udf_dir_operations = { | |
ca572727 | 137 | .llseek = generic_file_llseek, |
934c5e60 | 138 | .read = generic_read_dir, |
c51da20c | 139 | .iterate_shared = udf_readdir, |
2f07a88b | 140 | .unlocked_ioctl = udf_ioctl, |
1b061d92 | 141 | .fsync = generic_file_fsync, |
934c5e60 | 142 | }; |