Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[pandora-kernel.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/buffer_head.h>
34
35 #include "udf_i.h"
36 #include "udf_sb.h"
37
38 static int do_udf_readdir(struct inode *dir, struct file *filp,
39                           filldir_t filldir, void *dirent)
40 {
41         struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
42         struct fileIdentDesc *fi = NULL;
43         struct fileIdentDesc cfi;
44         int block, iblock;
45         loff_t nf_pos = (filp->f_pos - 1) << 2;
46         int flen;
47         unsigned char *fname = NULL;
48         unsigned char *nameptr;
49         uint16_t liu;
50         uint8_t lfi;
51         loff_t size = udf_ext0_offset(dir) + dir->i_size;
52         struct buffer_head *tmp, *bha[16];
53         struct kernel_lb_addr eloc;
54         uint32_t elen;
55         sector_t offset;
56         int i, num, ret = 0;
57         unsigned int dt_type;
58         struct extent_position epos = { NULL, 0, {0, 0} };
59         struct udf_inode_info *iinfo;
60
61         if (nf_pos >= size)
62                 goto out;
63
64         fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
65         if (!fname) {
66                 ret = -ENOMEM;
67                 goto out;
68         }
69
70         if (nf_pos == 0)
71                 nf_pos = udf_ext0_offset(dir);
72
73         fibh.soffset = fibh.eoffset = nf_pos & (dir->i_sb->s_blocksize - 1);
74         iinfo = UDF_I(dir);
75         if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
76                 if (inode_bmap(dir, nf_pos >> dir->i_sb->s_blocksize_bits,
77                     &epos, &eloc, &elen, &offset)
78                     != (EXT_RECORDED_ALLOCATED >> 30)) {
79                         ret = -ENOENT;
80                         goto out;
81                 }
82                 block = udf_get_lb_pblock(dir->i_sb, &eloc, offset);
83                 if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
84                         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
85                                 epos.offset -= sizeof(struct short_ad);
86                         else if (iinfo->i_alloc_type ==
87                                         ICBTAG_FLAG_AD_LONG)
88                                 epos.offset -= sizeof(struct long_ad);
89                 } else {
90                         offset = 0;
91                 }
92
93                 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) {
94                         ret = -EIO;
95                         goto out;
96                 }
97
98                 if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) {
99                         i = 16 >> (dir->i_sb->s_blocksize_bits - 9);
100                         if (i + offset > (elen >> dir->i_sb->s_blocksize_bits))
101                                 i = (elen >> dir->i_sb->s_blocksize_bits) - offset;
102                         for (num = 0; i > 0; i--) {
103                                 block = udf_get_lb_pblock(dir->i_sb, &eloc, offset + i);
104                                 tmp = udf_tgetblk(dir->i_sb, block);
105                                 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
106                                         bha[num++] = tmp;
107                                 else
108                                         brelse(tmp);
109                         }
110                         if (num) {
111                                 ll_rw_block(READA, num, bha);
112                                 for (i = 0; i < num; i++)
113                                         brelse(bha[i]);
114                         }
115                 }
116         }
117
118         while (nf_pos < size) {
119                 filp->f_pos = (nf_pos >> 2) + 1;
120
121                 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
122                                         &elen, &offset);
123                 if (!fi)
124                         goto out;
125
126                 liu = le16_to_cpu(cfi.lengthOfImpUse);
127                 lfi = cfi.lengthFileIdent;
128
129                 if (fibh.sbh == fibh.ebh) {
130                         nameptr = fi->fileIdent + liu;
131                 } else {
132                         int poffset;    /* Unpaded ending offset */
133
134                         poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
135
136                         if (poffset >= lfi) {
137                                 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
138                         } else {
139                                 nameptr = fname;
140                                 memcpy(nameptr, fi->fileIdent + liu,
141                                        lfi - poffset);
142                                 memcpy(nameptr + lfi - poffset,
143                                        fibh.ebh->b_data, poffset);
144                         }
145                 }
146
147                 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
148                         if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE))
149                                 continue;
150                 }
151
152                 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
153                         if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE))
154                                 continue;
155                 }
156
157                 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
158                         iblock = parent_ino(filp->f_path.dentry);
159                         flen = 2;
160                         memcpy(fname, "..", flen);
161                         dt_type = DT_DIR;
162                 } else {
163                         struct kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation);
164
165                         iblock = udf_get_lb_pblock(dir->i_sb, &tloc, 0);
166                         flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
167                         dt_type = DT_UNKNOWN;
168                 }
169
170                 if (flen && filldir(dirent, fname, flen, filp->f_pos,
171                                     iblock, dt_type) < 0)
172                         goto out;
173         } /* end while */
174
175         filp->f_pos = (nf_pos >> 2) + 1;
176
177 out:
178         if (fibh.sbh != fibh.ebh)
179                 brelse(fibh.ebh);
180         brelse(fibh.sbh);
181         brelse(epos.bh);
182         kfree(fname);
183
184         return ret;
185 }
186
187 static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
188 {
189         struct inode *dir = filp->f_path.dentry->d_inode;
190         int result;
191
192         if (filp->f_pos == 0) {
193                 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) {
194                         return 0;
195                 }
196                 filp->f_pos++;
197         }
198
199         result = do_udf_readdir(dir, filp, filldir, dirent);
200         return result;
201 }
202
203 /* readdir and lookup functions */
204 const struct file_operations udf_dir_operations = {
205         .llseek                 = generic_file_llseek,
206         .read                   = generic_read_dir,
207         .readdir                = udf_readdir,
208         .unlocked_ioctl         = udf_ioctl,
209         .fsync                  = generic_file_fsync,
210 };