x86, AMD IOMMU: add comments to core code
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / udf / dir.c
blob62dc270c69d1addaffb0919e1d5308421a2d1200
1 /*
2 * dir.c
4 * PURPOSE
5 * Directory handling routines for the OSTA-UDF(tm) filesystem.
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.
13 * (C) 1998-2004 Ben Fennema
15 * HISTORY
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.
27 #include "udfdecl.h"
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>
36 #include "udf_i.h"
37 #include "udf_sb.h"
39 static int do_udf_readdir(struct inode *dir, struct file *filp,
40 filldir_t filldir, void *dirent)
42 struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
43 struct fileIdentDesc *fi = NULL;
44 struct fileIdentDesc cfi;
45 int block, iblock;
46 loff_t nf_pos = (filp->f_pos - 1) << 2;
47 int flen;
48 char *fname = NULL;
49 char *nameptr;
50 uint16_t liu;
51 uint8_t lfi;
52 loff_t size = udf_ext0_offset(dir) + dir->i_size;
53 struct buffer_head *tmp, *bha[16];
54 kernel_lb_addr eloc;
55 uint32_t elen;
56 sector_t offset;
57 int i, num, ret = 0;
58 unsigned int dt_type;
59 struct extent_position epos = { NULL, 0, {0, 0} };
60 struct udf_inode_info *iinfo;
62 if (nf_pos >= size)
63 goto out;
65 fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
66 if (!fname) {
67 ret = -ENOMEM;
68 goto out;
71 if (nf_pos == 0)
72 nf_pos = udf_ext0_offset(dir);
74 fibh.soffset = fibh.eoffset = nf_pos & (dir->i_sb->s_blocksize - 1);
75 iinfo = UDF_I(dir);
76 if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
77 if (inode_bmap(dir, nf_pos >> dir->i_sb->s_blocksize_bits,
78 &epos, &eloc, &elen, &offset)
79 != (EXT_RECORDED_ALLOCATED >> 30)) {
80 ret = -ENOENT;
81 goto out;
83 block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
84 if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
85 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
86 epos.offset -= sizeof(short_ad);
87 else if (iinfo->i_alloc_type ==
88 ICBTAG_FLAG_AD_LONG)
89 epos.offset -= sizeof(long_ad);
90 } else {
91 offset = 0;
94 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) {
95 ret = -EIO;
96 goto out;
99 if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) {
100 i = 16 >> (dir->i_sb->s_blocksize_bits - 9);
101 if (i + offset > (elen >> dir->i_sb->s_blocksize_bits))
102 i = (elen >> dir->i_sb->s_blocksize_bits) - offset;
103 for (num = 0; i > 0; i--) {
104 block = udf_get_lb_pblock(dir->i_sb, eloc, offset + i);
105 tmp = udf_tgetblk(dir->i_sb, block);
106 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
107 bha[num++] = tmp;
108 else
109 brelse(tmp);
111 if (num) {
112 ll_rw_block(READA, num, bha);
113 for (i = 0; i < num; i++)
114 brelse(bha[i]);
119 while (nf_pos < size) {
120 filp->f_pos = (nf_pos >> 2) + 1;
122 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
123 &elen, &offset);
124 if (!fi)
125 goto out;
127 liu = le16_to_cpu(cfi.lengthOfImpUse);
128 lfi = cfi.lengthFileIdent;
130 if (fibh.sbh == fibh.ebh) {
131 nameptr = fi->fileIdent + liu;
132 } else {
133 int poffset; /* Unpaded ending offset */
135 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
137 if (poffset >= lfi) {
138 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
139 } else {
140 nameptr = fname;
141 memcpy(nameptr, fi->fileIdent + liu,
142 lfi - poffset);
143 memcpy(nameptr + lfi - poffset,
144 fibh.ebh->b_data, poffset);
148 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
149 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE))
150 continue;
153 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
154 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE))
155 continue;
158 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
159 iblock = parent_ino(filp->f_path.dentry);
160 flen = 2;
161 memcpy(fname, "..", flen);
162 dt_type = DT_DIR;
163 } else {
164 kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation);
166 iblock = udf_get_lb_pblock(dir->i_sb, tloc, 0);
167 flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
168 dt_type = DT_UNKNOWN;
171 if (flen && filldir(dirent, fname, flen, filp->f_pos,
172 iblock, dt_type) < 0)
173 goto out;
174 } /* end while */
176 filp->f_pos = (nf_pos >> 2) + 1;
178 out:
179 if (fibh.sbh != fibh.ebh)
180 brelse(fibh.ebh);
181 brelse(fibh.sbh);
182 brelse(epos.bh);
183 kfree(fname);
185 return ret;
188 static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
190 struct inode *dir = filp->f_path.dentry->d_inode;
191 int result;
193 lock_kernel();
195 if (filp->f_pos == 0) {
196 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) {
197 unlock_kernel();
198 return 0;
200 filp->f_pos++;
203 result = do_udf_readdir(dir, filp, filldir, dirent);
204 unlock_kernel();
205 return result;
208 /* readdir and lookup functions */
209 const struct file_operations udf_dir_operations = {
210 .read = generic_read_dir,
211 .readdir = udf_readdir,
212 .ioctl = udf_ioctl,
213 .fsync = udf_fsync_file,