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
39static int do_udf_readdir(struct inode *dir, struct file *filp,
40			  filldir_t filldir, void *dirent)
41{
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	unsigned char *fname = NULL;
49	unsigned 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	struct 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;
61
62	if (nf_pos >= size)
63		goto out;
64
65	fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
66	if (!fname) {
67		ret = -ENOMEM;
68		goto out;
69	}
70
71	if (nf_pos == 0)
72		nf_pos = udf_ext0_offset(dir);
73
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;
82		}
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(struct short_ad);
87			else if (iinfo->i_alloc_type ==
88					ICBTAG_FLAG_AD_LONG)
89				epos.offset -= sizeof(struct long_ad);
90		} else {
91			offset = 0;
92		}
93
94		if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) {
95			ret = -EIO;
96			goto out;
97		}
98
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);
110			}
111			if (num) {
112				ll_rw_block(READA, num, bha);
113				for (i = 0; i < num; i++)
114					brelse(bha[i]);
115			}
116		}
117	}
118
119	while (nf_pos < size) {
120		filp->f_pos = (nf_pos >> 2) + 1;
121
122		fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
123					&elen, &offset);
124		if (!fi)
125			goto out;
126
127		liu = le16_to_cpu(cfi.lengthOfImpUse);
128		lfi = cfi.lengthFileIdent;
129
130		if (fibh.sbh == fibh.ebh) {
131			nameptr = fi->fileIdent + liu;
132		} else {
133			int poffset;	/* Unpaded ending offset */
134
135			poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
136
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);
145			}
146		}
147
148		if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
149			if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE))
150				continue;
151		}
152
153		if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
154			if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE))
155				continue;
156		}
157
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			struct kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation);
165
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;
169		}
170
171		if (flen && filldir(dirent, fname, flen, filp->f_pos,
172				    iblock, dt_type) < 0)
173			goto out;
174	} /* end while */
175
176	filp->f_pos = (nf_pos >> 2) + 1;
177
178out:
179	if (fibh.sbh != fibh.ebh)
180		brelse(fibh.ebh);
181	brelse(fibh.sbh);
182	brelse(epos.bh);
183	kfree(fname);
184
185	return ret;
186}
187
188static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
189{
190	struct inode *dir = filp->f_path.dentry->d_inode;
191	int result;
192
193	lock_kernel();
194
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;
199		}
200		filp->f_pos++;
201	}
202
203	result = do_udf_readdir(dir, filp, filldir, dirent);
204	unlock_kernel();
205 	return result;
206}
207
208/* readdir and lookup functions */
209const struct file_operations udf_dir_operations = {
210	.llseek			= generic_file_llseek,
211	.read			= generic_read_dir,
212	.readdir		= udf_readdir,
213	.unlocked_ioctl		= udf_ioctl,
214	.fsync			= generic_file_fsync,
215};
216