1 /*
2 * dir.c
3 *
4 * PURPOSE
5 * Directory handling routines for the OSTA-UDF(tm) filesystem.
6 *
7 * CONTACTS
8 * E-mail regarding any portion of the Linux UDF file system should be
9 * directed to the development team mailing list (run by majordomo):
10 * linux_udf@hootie.lvld.hp.com
11 *
12 * COPYRIGHT
13 * This file is distributed under the terms of the GNU General Public
14 * License (GPL). Copies of the GPL can be obtained from:
15 * ftp://prep.ai.mit.edu/pub/gnu/GPL
16 * Each contributing author retains all rights to their own work.
17 *
18 * (C) 1998-2000 Ben Fennema
19 *
20 * HISTORY
21 *
22 * 10/05/98 dgb Split directory operations into it's own file
23 * Implemented directory reads via do_udf_readdir
24 * 10/06/98 Made directory operations work!
25 * 11/17/98 Rewrote directory to support ICB_FLAG_AD_LONG
26 * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading
27 * across blocks.
28 * 12/12/98 Split out the lookup code to namei.c. bulk of directory
29 * code now in directory.c:udf_fileident_read.
30 */
31
32 #include "udfdecl.h"
33
34 #if defined(__linux__) && defined(__KERNEL__)
35 #include <linux/version.h>
36 #include "udf_i.h"
37 #include "udf_sb.h"
38 #include <linux/string.h>
39 #include <linux/errno.h>
40 #include <linux/mm.h>
41 #include <linux/malloc.h>
42 #include <linux/udf_fs.h>
43 #endif
44
45 /* Prototypes for file operations */
46 static int udf_readdir(struct file *, void *, filldir_t);
47 static int do_udf_readdir(struct inode *, struct file *, filldir_t, void *);
48
49 /* readdir and lookup functions */
50
51 struct file_operations udf_dir_operations = {
52 read: generic_read_dir,
53 readdir: udf_readdir,
54 ioctl: udf_ioctl,
55 fsync: udf_sync_file,
56 };
57
58 /*
59 * udf_readdir
60 *
61 * PURPOSE
62 * Read a directory entry.
63 *
64 * DESCRIPTION
65 * Optional - sys_getdents() will return -ENOTDIR if this routine is not
66 * available.
67 *
68 * Refer to sys_getdents() in fs/readdir.c
69 * sys_getdents() -> .
70 *
71 * PRE-CONDITIONS
72 * filp Pointer to directory file.
73 * buf Pointer to directory entry buffer.
74 * filldir Pointer to filldir function.
75 *
76 * POST-CONDITIONS
77 * <return> >=0 on success.
78 *
79 * HISTORY
80 * July 1, 1997 - Andrew E. Mileski
81 * Written, tested, and released.
82 */
83
84 int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
85 {
86 struct inode *dir = filp->f_dentry->d_inode;
87 int result;
88
89 if ( filp->f_pos == 0 )
90 {
91 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR))
92 return 0;
93 }
94
95 result = do_udf_readdir(dir, filp, filldir, dirent);
96 UPDATE_ATIME(dir);
97 return result;
98 }
99
100 static int
101 do_udf_readdir(struct inode * dir, struct file *filp, filldir_t filldir, void *dirent)
102 {
103 struct udf_fileident_bh fibh;
104 struct FileIdentDesc *fi=NULL;
105 struct FileIdentDesc cfi;
106 int block, iblock;
107 loff_t nf_pos = filp->f_pos;
108 int flen;
109 char fname[255];
110 char *nameptr;
111 Uint16 liu;
112 Uint8 lfi;
113 loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2;
114 struct buffer_head * bh = NULL;
115 lb_addr bloc, eloc;
116 Uint32 extoffset, elen, offset;
117
118 if (nf_pos >= size)
119 return 1;
120
121 if (nf_pos == 0)
122 nf_pos = (udf_ext0_offset(dir) >> 2);
123
124 fibh.soffset = fibh.eoffset = (nf_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;
125 if (inode_bmap(dir, nf_pos >> (dir->i_sb->s_blocksize_bits - 2),
126 &bloc, &extoffset, &eloc, &elen, &offset, &bh) == EXTENT_RECORDED_ALLOCATED)
127 {
128 block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
129 if ((++offset << dir->i_sb->s_blocksize_bits) < elen)
130 {
131 if (UDF_I_ALLOCTYPE(dir) == ICB_FLAG_AD_SHORT)
132 extoffset -= sizeof(short_ad);
133 else if (UDF_I_ALLOCTYPE(dir) == ICB_FLAG_AD_LONG)
134 extoffset -= sizeof(long_ad);
135 }
136 else
137 offset = 0;
138 }
139 else
140 {
141 udf_release_data(bh);
142 return 0;
143 }
144
145 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block, dir->i_sb->s_blocksize)))
146 {
147 udf_release_data(bh);
148 return 0;
149 }
150
151 while ( nf_pos < size )
152 {
153 filp->f_pos = nf_pos;
154
155 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &bloc, &extoffset, &eloc, &elen, &offset, &bh);
156
157 if (!fi)
158 {
159 if (fibh.sbh != fibh.ebh)
160 udf_release_data(fibh.ebh);
161 udf_release_data(fibh.sbh);
162 udf_release_data(bh);
163 return 1;
164 }
165
166 liu = le16_to_cpu(cfi.lengthOfImpUse);
167 lfi = cfi.lengthFileIdent;
168
169 if (fibh.sbh == fibh.ebh)
170 nameptr = fi->fileIdent + liu;
171 else
172 {
173 int poffset; /* Unpaded ending offset */
174
175 poffset = fibh.soffset + sizeof(struct FileIdentDesc) + liu + lfi;
176
177 if (poffset >= lfi)
178 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
179 else
180 {
181 nameptr = fname;
182 memcpy(nameptr, fi->fileIdent + liu, lfi - poffset);
183 memcpy(nameptr + lfi - poffset, fibh.ebh->b_data, poffset);
184 }
185 }
186
187 if ( (cfi.fileCharacteristics & FILE_DELETED) != 0 )
188 {
189 if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE) )
190 continue;
191 }
192
193 if ( (cfi.fileCharacteristics & FILE_HIDDEN) != 0 )
194 {
195 if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE) )
196 continue;
197 }
198
199 iblock = udf_get_lb_pblock(dir->i_sb, lelb_to_cpu(cfi.icb.extLocation), 0);
200
201 if (!lfi) /* parent directory */
202 {
203 if (filldir(dirent, "..", 2, filp->f_pos, filp->f_dentry->d_parent->d_inode->i_ino, DT_DIR))
204 {
205 if (fibh.sbh != fibh.ebh)
206 udf_release_data(fibh.ebh);
207 udf_release_data(fibh.sbh);
208 udf_release_data(bh);
209 return 1;
210 }
211 }
212 else
213 {
214 if ((flen = udf_get_filename(nameptr, fname, lfi)))
215 {
216 if (filldir(dirent, fname, flen, filp->f_pos, iblock, DT_UNKNOWN))
217 {
218 if (fibh.sbh != fibh.ebh)
219 udf_release_data(fibh.ebh);
220 udf_release_data(fibh.sbh);
221 udf_release_data(bh);
222 return 1; /* halt enum */
223 }
224 }
225 }
226 } /* end while */
227
228 filp->f_pos = nf_pos;
229
230 if (fibh.sbh != fibh.ebh)
231 udf_release_data(fibh.ebh);
232 udf_release_data(fibh.sbh);
233 udf_release_data(bh);
234
235 if ( filp->f_pos >= size)
236 return 1;
237 else
238 return 0;
239 }
240
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