5 * Directory handling routines for the OSTA-UDF(tm) filesystem.
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.
13 * (C) 1998-2004 Ben Fennema
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
23 * 12/12/98 Split out the lookup code to namei.c. bulk of directory
24 * code now in directory.c:udf_fileident_read.
29 #include <linux/string.h>
30 #include <linux/errno.h>
32 #include <linux/slab.h>
33 #include <linux/bio.h>
34 #include <linux/iversion.h>
39 static int udf_readdir(struct file
*file
, struct dir_context
*ctx
)
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
, emit_pos
= 0;
49 unsigned char *fname
= NULL
, *copy_name
= NULL
;
50 unsigned char *nameptr
;
53 loff_t size
= udf_ext0_offset(dir
) + dir
->i_size
;
54 struct buffer_head
*tmp
, *bha
[16];
55 struct kernel_lb_addr eloc
;
59 struct extent_position epos
= { NULL
, 0, {0, 0} };
60 struct super_block
*sb
= dir
->i_sb
;
61 bool pos_valid
= false;
64 if (!dir_emit_dot(file
, ctx
))
68 nf_pos
= (ctx
->pos
- 1) << 2;
73 * Something changed since last readdir (either lseek was called or dir
74 * changed)? We need to verify the position correctly points at the
75 * beginning of some dir entry so that the directory parsing code does
76 * not get confused. Since UDF does not have any reliable way of
77 * identifying beginning of dir entry (names are under user control),
78 * we need to scan the directory from the beginning.
80 if (!inode_eq_iversion(dir
, file
->f_version
)) {
87 fname
= kmalloc(UDF_NAME_LEN
, GFP_NOFS
);
94 nf_pos
= udf_ext0_offset(dir
);
96 fibh
.soffset
= fibh
.eoffset
= nf_pos
& (sb
->s_blocksize
- 1);
97 if (iinfo
->i_alloc_type
!= ICBTAG_FLAG_AD_IN_ICB
) {
98 if (inode_bmap(dir
, nf_pos
>> sb
->s_blocksize_bits
,
99 &epos
, &eloc
, &elen
, &offset
)
100 != (EXT_RECORDED_ALLOCATED
>> 30)) {
104 block
= udf_get_lb_pblock(sb
, &eloc
, offset
);
105 if ((++offset
<< sb
->s_blocksize_bits
) < elen
) {
106 if (iinfo
->i_alloc_type
== ICBTAG_FLAG_AD_SHORT
)
107 epos
.offset
-= sizeof(struct short_ad
);
108 else if (iinfo
->i_alloc_type
==
110 epos
.offset
-= sizeof(struct long_ad
);
115 if (!(fibh
.sbh
= fibh
.ebh
= udf_tread(sb
, block
))) {
120 if (!(offset
& ((16 >> (sb
->s_blocksize_bits
- 9)) - 1))) {
121 i
= 16 >> (sb
->s_blocksize_bits
- 9);
122 if (i
+ offset
> (elen
>> sb
->s_blocksize_bits
))
123 i
= (elen
>> sb
->s_blocksize_bits
) - offset
;
124 for (num
= 0; i
> 0; i
--) {
125 block
= udf_get_lb_pblock(sb
, &eloc
, offset
+ i
);
126 tmp
= udf_tgetblk(sb
, block
);
127 if (tmp
&& !buffer_uptodate(tmp
) && !buffer_locked(tmp
))
133 ll_rw_block(REQ_OP_READ
, REQ_RAHEAD
, num
, bha
);
134 for (i
= 0; i
< num
; i
++)
140 while (nf_pos
< size
) {
141 struct kernel_lb_addr tloc
;
142 loff_t cur_pos
= nf_pos
;
144 /* Update file position only if we got past the current one */
145 if (nf_pos
>= emit_pos
) {
146 ctx
->pos
= (nf_pos
>> 2) + 1;
150 fi
= udf_fileident_read(dir
, &nf_pos
, &fibh
, &cfi
, &epos
, &eloc
,
154 /* Still not at offset where user asked us to read from? */
155 if (cur_pos
< emit_pos
)
158 liu
= le16_to_cpu(cfi
.lengthOfImpUse
);
159 lfi
= cfi
.lengthFileIdent
;
161 if (fibh
.sbh
== fibh
.ebh
) {
162 nameptr
= udf_get_fi_ident(fi
);
164 int poffset
; /* Unpaded ending offset */
166 poffset
= fibh
.soffset
+ sizeof(struct fileIdentDesc
) + liu
+ lfi
;
168 if (poffset
>= lfi
) {
169 nameptr
= (char *)(fibh
.ebh
->b_data
+ poffset
- lfi
);
172 copy_name
= kmalloc(UDF_NAME_LEN
,
180 memcpy(nameptr
, udf_get_fi_ident(fi
),
182 memcpy(nameptr
+ lfi
- poffset
,
183 fibh
.ebh
->b_data
, poffset
);
187 if ((cfi
.fileCharacteristics
& FID_FILE_CHAR_DELETED
) != 0) {
188 if (!UDF_QUERY_FLAG(sb
, UDF_FLAG_UNDELETE
))
192 if ((cfi
.fileCharacteristics
& FID_FILE_CHAR_HIDDEN
) != 0) {
193 if (!UDF_QUERY_FLAG(sb
, UDF_FLAG_UNHIDE
))
197 if (cfi
.fileCharacteristics
& FID_FILE_CHAR_PARENT
) {
198 if (!dir_emit_dotdot(file
, ctx
))
203 flen
= udf_get_filename(sb
, nameptr
, lfi
, fname
, UDF_NAME_LEN
);
207 tloc
= lelb_to_cpu(cfi
.icb
.extLocation
);
208 iblock
= udf_get_lb_pblock(sb
, &tloc
, 0);
209 if (!dir_emit(ctx
, fname
, flen
, iblock
, DT_UNKNOWN
))
213 ctx
->pos
= (nf_pos
>> 2) + 1;
218 file
->f_version
= inode_query_iversion(dir
);
219 if (fibh
.sbh
!= fibh
.ebh
)
229 /* readdir and lookup functions */
230 const struct file_operations udf_dir_operations
= {
231 .llseek
= generic_file_llseek
,
232 .read
= generic_read_dir
,
233 .iterate_shared
= udf_readdir
,
234 .unlocked_ioctl
= udf_ioctl
,
235 .fsync
= generic_file_fsync
,