remove pointers to the defunct UDF mailing list
[linux-2.6.git] / fs / udf / dir.c
1 /*
2  * dir.c
3  *
4  * PURPOSE
5  *  Directory handling routines for the OSTA-UDF(tm) filesystem.
6  *
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>
33 #include <linux/smp_lock.h>
34 #include <linux/buffer_head.h>
35
36 #include "udf_i.h"
37 #include "udf_sb.h"
38
39 /* Prototypes for file operations */
40 static int udf_readdir(struct file *, void *, filldir_t);
41 static int do_udf_readdir(struct inode *, struct file *, filldir_t, void *);
42
43 /* readdir and lookup functions */
44
45 struct file_operations udf_dir_operations = {
46         .read                   = generic_read_dir,
47         .readdir                = udf_readdir,
48         .ioctl                  = udf_ioctl,
49         .fsync                  = udf_fsync_file,
50 };
51
52 /*
53  * udf_readdir
54  *
55  * PURPOSE
56  *      Read a directory entry.
57  *
58  * DESCRIPTION
59  *      Optional - sys_getdents() will return -ENOTDIR if this routine is not
60  *      available.
61  *
62  *      Refer to sys_getdents() in fs/readdir.c
63  *      sys_getdents() -> .
64  *
65  * PRE-CONDITIONS
66  *      filp                    Pointer to directory file.
67  *      buf                     Pointer to directory entry buffer.
68  *      filldir                 Pointer to filldir function.
69  *
70  * POST-CONDITIONS
71  *      <return>                >=0 on success.
72  *
73  * HISTORY
74  *      July 1, 1997 - Andrew E. Mileski
75  *      Written, tested, and released.
76  */
77
78 int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
79 {
80         struct inode *dir = filp->f_dentry->d_inode;
81         int result;
82
83         lock_kernel();
84
85         if ( filp->f_pos == 0 ) 
86         {
87                 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0)
88                 {
89                         unlock_kernel();
90                         return 0;
91                 }
92                 filp->f_pos ++;
93         }
94
95         result = do_udf_readdir(dir, filp, filldir, dirent);
96         unlock_kernel();
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 - 1;
108         int flen;
109         char fname[UDF_NAME_LEN];
110         char *nameptr;
111         uint16_t liu;
112         uint8_t lfi;
113         loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2;
114         struct buffer_head * bh = NULL, * tmp, * bha[16];
115         kernel_lb_addr bloc, eloc;
116         uint32_t extoffset, elen, offset;
117         int i, num;
118         unsigned int dt_type;
119
120         if (nf_pos >= size)
121                 return 0;
122
123         if (nf_pos == 0)
124                 nf_pos = (udf_ext0_offset(dir) >> 2);
125
126         fibh.soffset = fibh.eoffset = (nf_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;
127         if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB)
128                 fibh.sbh = fibh.ebh = NULL;
129         else if (inode_bmap(dir, nf_pos >> (dir->i_sb->s_blocksize_bits - 2),
130                 &bloc, &extoffset, &eloc, &elen, &offset, &bh) == (EXT_RECORDED_ALLOCATED >> 30))
131         {
132                 offset >>= dir->i_sb->s_blocksize_bits;
133                 block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
134                 if ((++offset << dir->i_sb->s_blocksize_bits) < elen)
135                 {
136                         if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT)
137                                 extoffset -= sizeof(short_ad);
138                         else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG)
139                                 extoffset -= sizeof(long_ad);
140                 }
141                 else
142                         offset = 0;
143
144                 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block)))
145                 {
146                         udf_release_data(bh);
147                         return -EIO;
148                 }
149         
150                 if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9))-1)))
151                 {
152                         i = 16 >> (dir->i_sb->s_blocksize_bits - 9);
153                         if (i+offset > (elen >> dir->i_sb->s_blocksize_bits))
154                                 i = (elen >> dir->i_sb->s_blocksize_bits)-offset;
155                         for (num=0; i>0; i--)
156                         {
157                                 block = udf_get_lb_pblock(dir->i_sb, eloc, offset+i);
158                                 tmp = udf_tgetblk(dir->i_sb, block);
159                                 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
160                                         bha[num++] = tmp;
161                                 else
162                                         brelse(tmp);
163                         }
164                         if (num)
165                         {
166                                 ll_rw_block(READA, num, bha);
167                                 for (i=0; i<num; i++)
168                                         brelse(bha[i]);
169                         }
170                 }
171         }
172         else
173         {
174                 udf_release_data(bh);
175                 return -ENOENT;
176         }
177
178         while ( nf_pos < size )
179         {
180                 filp->f_pos = nf_pos + 1;
181
182                 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &bloc, &extoffset, &eloc, &elen, &offset, &bh);
183
184                 if (!fi)
185                 {
186                         if (fibh.sbh != fibh.ebh)
187                                 udf_release_data(fibh.ebh);
188                         udf_release_data(fibh.sbh);
189                         udf_release_data(bh);
190                         return 0;
191                 }
192
193                 liu = le16_to_cpu(cfi.lengthOfImpUse);
194                 lfi = cfi.lengthFileIdent;
195
196                 if (fibh.sbh == fibh.ebh)
197                         nameptr = fi->fileIdent + liu;
198                 else
199                 {
200                         int poffset;    /* Unpaded ending offset */
201
202                         poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
203
204                         if (poffset >= lfi)
205                                 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
206                         else
207                         {
208                                 nameptr = fname;
209                                 memcpy(nameptr, fi->fileIdent + liu, lfi - poffset);
210                                 memcpy(nameptr + lfi - poffset, fibh.ebh->b_data, poffset);
211                         }
212                 }
213
214                 if ( (cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0 )
215                 {
216                         if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE) )
217                                 continue;
218                 }
219                 
220                 if ( (cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0 )
221                 {
222                         if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE) )
223                                 continue;
224                 }
225
226                 if ( cfi.fileCharacteristics & FID_FILE_CHAR_PARENT )
227                 {
228                         iblock = parent_ino(filp->f_dentry);
229                         flen = 2;
230                         memcpy(fname, "..", flen);
231                         dt_type = DT_DIR;
232                 }
233                 else
234                 {
235                         kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation);
236
237                         iblock = udf_get_lb_pblock(dir->i_sb, tloc, 0);
238                         flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
239                         dt_type = DT_UNKNOWN;
240                 }
241
242                 if (flen)
243                 {
244                         if (filldir(dirent, fname, flen, filp->f_pos, iblock, dt_type) < 0)
245                         {
246                                 if (fibh.sbh != fibh.ebh)
247                                         udf_release_data(fibh.ebh);
248                                 udf_release_data(fibh.sbh);
249                                 udf_release_data(bh);
250                                 return 0;
251                         }
252                 }
253         } /* end while */
254
255         filp->f_pos = nf_pos + 1;
256
257         if (fibh.sbh != fibh.ebh)
258                 udf_release_data(fibh.ebh);
259         udf_release_data(fibh.sbh);
260         udf_release_data(bh);
261
262         return 0;
263 }