[linux.git] / fs / isofs / dir.c

/*
 *  linux/fs/isofs/dir.c
 *
 *  (C) 1992, 1993, 1994  Eric Youngdale Modified for ISO 9660 filesystem.
 *
 *  (C) 1991  Linus Torvalds - minix filesystem
 *
 *  Steve Beynon		       : Missing last directory entries fixed
 *  ([email protected])      : 21st June 1996
 * 
 *  isofs directory handling functions
 */
#include <linux/smp_lock.h>
#include "isofs.h"

static int isofs_readdir(struct file *, void *, filldir_t);

const struct file_operations isofs_dir_operations =
{
	.read		= generic_read_dir,
	.readdir	= isofs_readdir,
};

/*
 * directories can handle most operations...
 */
const struct inode_operations isofs_dir_inode_operations =
{
	.lookup		= isofs_lookup,
};

int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode)
{
	char * old = de->name;
	int len = de->name_len[0];
	int i;
			
	for (i = 0; i < len; i++) {
		unsigned char c = old[i];
		if (!c)
			break;

		if (c >= 'A' && c <= 'Z')
			c |= 0x20;	/* lower case */

		/* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */
		if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1')
			break;

		/* Drop trailing ';1' */
		if (c == ';' && i == len - 2 && old[i + 1] == '1')
			break;

		/* Convert remaining ';' to '.' */
		/* Also '/' to '.' (broken Acorn-generated ISO9660 images) */
		if (c == ';' || c == '/')
			c = '.';

		new[i] = c;
	}
	return i;
}

/* Acorn extensions written by Matthew Wilcox <[email protected]> 1998 */
int get_acorn_filename(struct iso_directory_record * de,
			    char * retname, struct inode * inode)
{
	int std;
	unsigned char * chr;
	int retnamlen = isofs_name_translate(de, retname, inode);
	if (retnamlen == 0) return 0;
	std = sizeof(struct iso_directory_record) + de->name_len[0];
	if (std & 1) std++;
	if ((*((unsigned char *) de) - std) != 32) return retnamlen;
	chr = ((unsigned char *) de) + std;
	if (strncmp(chr, "ARCHIMEDES", 10)) return retnamlen;
	if ((*retname == '_') && ((chr[19] & 1) == 1)) *retname = '!';
	if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff)
		&& ((chr[12] & 0xf0) == 0xf0))
	{
		retname[retnamlen] = ',';
		sprintf(retname+retnamlen+1, "%3.3x",
			((chr[12] & 0xf) << 8) | chr[11]);
		retnamlen += 4;
	}
	return retnamlen;
}

/*
 * This should _really_ be cleaned up some day..
 */
static int do_isofs_readdir(struct inode *inode, struct file *filp,
		void *dirent, filldir_t filldir,
		char * tmpname, struct iso_directory_record * tmpde)
{
	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
	unsigned char bufbits = ISOFS_BUFFER_BITS(inode);
	unsigned long block, offset, block_saved, offset_saved;
	unsigned long inode_number = 0;	/* Quiet GCC */
	struct buffer_head *bh = NULL;
	int len;
	int map;
	int first_de = 1;
	char *p = NULL;		/* Quiet GCC */
	struct iso_directory_record *de;
	struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);

	offset = filp->f_pos & (bufsize - 1);
	block = filp->f_pos >> bufbits;

	while (filp->f_pos < inode->i_size) {
		int de_len;

		if (!bh) {
			bh = isofs_bread(inode, block);
			if (!bh)
				return 0;
		}

		de = (struct iso_directory_record *) (bh->b_data + offset);

		de_len = *(unsigned char *) de;

		/* If the length byte is zero, we should move on to the next
		   CDROM sector.  If we are at the end of the directory, we
		   kick out of the while loop. */

		if (de_len == 0) {
			brelse(bh);
			bh = NULL;
			filp->f_pos = (filp->f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
			block = filp->f_pos >> bufbits;
			offset = 0;
			continue;
		}

		block_saved = block;
		offset_saved = offset;
		offset += de_len;

		/* Make sure we have a full directory entry */
		if (offset >= bufsize) {
			int slop = bufsize - offset + de_len;
			memcpy(tmpde, de, slop);
			offset &= bufsize - 1;
			block++;
			brelse(bh);
			bh = NULL;
			if (offset) {
				bh = isofs_bread(inode, block);
				if (!bh)
					return 0;
				memcpy((void *) tmpde + slop, bh->b_data, offset);
			}
			de = tmpde;
		}

		if (first_de) {
			isofs_normalize_block_and_offset(de,
							 &block_saved,
							 &offset_saved);
			inode_number = isofs_get_ino(block_saved,
						     offset_saved,
						     bufbits);
		}

		if (de->flags[-sbi->s_high_sierra] & 0x80) {
			first_de = 0;
			filp->f_pos += de_len;
			continue;
		}
		first_de = 1;

		/* Handle the case of the '.' directory */
		if (de->name_len[0] == 1 && de->name[0] == 0) {
			if (filldir(dirent, ".", 1, filp->f_pos, inode->i_ino, DT_DIR) < 0)
				break;
			filp->f_pos += de_len;
			continue;
		}

		len = 0;

		/* Handle the case of the '..' directory */
		if (de->name_len[0] == 1 && de->name[0] == 1) {
			inode_number = parent_ino(filp->f_path.dentry);
			if (filldir(dirent, "..", 2, filp->f_pos, inode_number, DT_DIR) < 0)
				break;
			filp->f_pos += de_len;
			continue;
		}

		/* Handle everything else.  Do name translation if there
		   is no Rock Ridge NM field. */

		/*
		 * Do not report hidden files if so instructed, or associated
		 * files unless instructed to do so
		 */
		if ((sbi->s_hide == 'y' &&
				(de->flags[-sbi->s_high_sierra] & 1)) ||
		      (sbi->s_showassoc =='n' &&
				(de->flags[-sbi->s_high_sierra] & 4))) {
			filp->f_pos += de_len;
			continue;
		}

		map = 1;
		if (sbi->s_rock) {
			len = get_rock_ridge_filename(de, tmpname, inode);
			if (len != 0) {		/* may be -1 */
				p = tmpname;
				map = 0;
			}
		}
		if (map) {
#ifdef CONFIG_JOLIET
			if (sbi->s_joliet_level) {
				len = get_joliet_filename(de, tmpname, inode);
				p = tmpname;
			} else
#endif
			if (sbi->s_mapping == 'a') {
				len = get_acorn_filename(de, tmpname, inode);
				p = tmpname;
			} else
			if (sbi->s_mapping == 'n') {
				len = isofs_name_translate(de, tmpname, inode);
				p = tmpname;
			} else {
				p = de->name;
				len = de->name_len[0];
			}
		}
		if (len > 0) {
			if (filldir(dirent, p, len, filp->f_pos, inode_number, DT_UNKNOWN) < 0)
				break;
		}
		filp->f_pos += de_len;

		continue;
	}
	if (bh) brelse(bh);
	return 0;
}

/*
 * Handle allocation of temporary space for name translation and
 * handling split directory entries.. The real work is done by
 * "do_isofs_readdir()".
 */
static int isofs_readdir(struct file *filp,
		void *dirent, filldir_t filldir)
{
	int result;
	char * tmpname;
	struct iso_directory_record * tmpde;
	struct inode *inode = filp->f_path.dentry->d_inode;

	tmpname = (char *)__get_free_page(GFP_KERNEL);
	if (tmpname == NULL)
		return -ENOMEM;

	lock_kernel();
	tmpde = (struct iso_directory_record *) (tmpname+1024);

	result = do_isofs_readdir(inode, filp, dirent, filldir, tmpname, tmpde);

	free_page((unsigned long) tmpname);
	unlock_kernel();
	return result;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/isofs/dir.c
	3	*
	4	* (C) 1992, 1993, 1994 Eric Youngdale Modified for ISO 9660 filesystem.
	5	*
	6	* (C) 1991 Linus Torvalds - minix filesystem
	7	*
	8	* Steve Beynon : Missing last directory entries fixed
	9	* ([email protected]) : 21st June 1996
	10	*
	11	* isofs directory handling functions
	12	*/
1da177e4	13	#include <linux/smp_lock.h>
94f2f715	14	#include "isofs.h"
1da177e4 LT	15
	16	static int isofs_readdir(struct file , void , filldir_t);
	17
4b6f5d20	18	const struct file_operations isofs_dir_operations =
1da177e4 LT	19	{
	20	.read = generic_read_dir,
	21	.readdir = isofs_readdir,
	22	};
	23
	24	/*
	25	* directories can handle most operations...
	26	*/
92e1d5be	27	const struct inode_operations isofs_dir_inode_operations =
1da177e4 LT	28	{
	29	.lookup = isofs_lookup,
	30	};
	31
	32	int isofs_name_translate(struct iso_directory_record de, char new, struct inode *inode)
	33	{
	34	char * old = de->name;
	35	int len = de->name_len[0];
	36	int i;
	37
	38	for (i = 0; i < len; i++) {
	39	unsigned char c = old[i];
	40	if (!c)
	41	break;
	42
	43	if (c >= 'A' && c <= 'Z')
	44	c \|= 0x20; /* lower case */
	45
	46	/* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */
	47	if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1')
	48	break;
	49
	50	/* Drop trailing ';1' */
	51	if (c == ';' && i == len - 2 && old[i + 1] == '1')
	52	break;
	53
	54	/* Convert remaining ';' to '.' */
	55	/* Also '/' to '.' (broken Acorn-generated ISO9660 images) */
	56	if (c == ';' \|\| c == '/')
	57	c = '.';
	58
	59	new[i] = c;
	60	}
	61	return i;
	62	}
	63
	64	/* Acorn extensions written by Matthew Wilcox <[email protected]> 1998 */
	65	int get_acorn_filename(struct iso_directory_record * de,
	66	char * retname, struct inode * inode)
	67	{
	68	int std;
	69	unsigned char * chr;
	70	int retnamlen = isofs_name_translate(de, retname, inode);
	71	if (retnamlen == 0) return 0;
	72	std = sizeof(struct iso_directory_record) + de->name_len[0];
	73	if (std & 1) std++;
	74	if ((((unsigned char ) de) - std) != 32) return retnamlen;
	75	chr = ((unsigned char *) de) + std;
	76	if (strncmp(chr, "ARCHIMEDES", 10)) return retnamlen;
	77	if ((retname == '_') && ((chr[19] & 1) == 1)) retname = '!';
	78	if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff)
	79	&& ((chr[12] & 0xf0) == 0xf0))
	80	{
	81	retname[retnamlen] = ',';
	82	sprintf(retname+retnamlen+1, "%3.3x",
	83	((chr[12] & 0xf) << 8) \| chr[11]);
	84	retnamlen += 4;
	85	}
	86	return retnamlen;
	87	}
	88
	89	/*
	90	* This should _really_ be cleaned up some day..
	91	*/
92	static int do_isofs_readdir(struct inode inode, struct file filp,
93	void *dirent, filldir_t filldir,
94	char * tmpname, struct iso_directory_record * tmpde)
95	{
96	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
97	unsigned char bufbits = ISOFS_BUFFER_BITS(inode);
98	unsigned long block, offset, block_saved, offset_saved;
99	unsigned long inode_number = 0; /* Quiet GCC */
100	struct buffer_head *bh = NULL;
101	int len;
102	int map;
103	int first_de = 1;
104	char p = NULL; / Quiet GCC */
105	struct iso_directory_record *de;
106	struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
107
108	offset = filp->f_pos & (bufsize - 1);
109	block = filp->f_pos >> bufbits;
110
111	while (filp->f_pos < inode->i_size) {
112	int de_len;
113
114	if (!bh) {
115	bh = isofs_bread(inode, block);
116	if (!bh)
117	return 0;
118	}
119
120	de = (struct iso_directory_record *) (bh->b_data + offset);
121
122	de_len = (unsigned char ) de;
123
124	/* If the length byte is zero, we should move on to the next
125	CDROM sector. If we are at the end of the directory, we
126	kick out of the while loop. */
127
128	if (de_len == 0) {
129	brelse(bh);
130	bh = NULL;
131	filp->f_pos = (filp->f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
132	block = filp->f_pos >> bufbits;
133	offset = 0;
134	continue;
135	}
136
137	block_saved = block;
138	offset_saved = offset;
139	offset += de_len;
140
141	/* Make sure we have a full directory entry */
142	if (offset >= bufsize) {
143	int slop = bufsize - offset + de_len;
144	memcpy(tmpde, de, slop);
145	offset &= bufsize - 1;
146	block++;
147	brelse(bh);
148	bh = NULL;
149	if (offset) {
150	bh = isofs_bread(inode, block);
151	if (!bh)
152	return 0;
153	memcpy((void *) tmpde + slop, bh->b_data, offset);
154	}
155	de = tmpde;
156	}
157
158	if (first_de) {
159	isofs_normalize_block_and_offset(de,
160	&block_saved,
161	&offset_saved);
162	inode_number = isofs_get_ino(block_saved,
163	offset_saved,
164	bufbits);
165	}
166
167	if (de->flags[-sbi->s_high_sierra] & 0x80) {
168	first_de = 0;
169	filp->f_pos += de_len;
170	continue;
171	}
172	first_de = 1;
173
174	/* Handle the case of the '.' directory */
175	if (de->name_len[0] == 1 && de->name[0] == 0) {
176	if (filldir(dirent, ".", 1, filp->f_pos, inode->i_ino, DT_DIR) < 0)
177	break;
178	filp->f_pos += de_len;
179	continue;
180	}
181
182	len = 0;
183
184	/* Handle the case of the '..' directory */
185	if (de->name_len[0] == 1 && de->name[0] == 1) {
2485822d	186	inode_number = parent_ino(filp->f_path.dentry);
1da177e4 LT	187	if (filldir(dirent, "..", 2, filp->f_pos, inode_number, DT_DIR) < 0)
	188	break;
	189	filp->f_pos += de_len;
	190	continue;
	191	}
	192
	193	/* Handle everything else. Do name translation if there
	194	is no Rock Ridge NM field. */
9769f4eb JW	195
	196	/*
	197	* Do not report hidden files if so instructed, or associated
	198	* files unless instructed to do so
	199	*/
	200	if ((sbi->s_hide == 'y' &&
	201	(de->flags[-sbi->s_high_sierra] & 1)) \|\|
	202	(sbi->s_showassoc =='n' &&
	203	(de->flags[-sbi->s_high_sierra] & 4))) {
	204	filp->f_pos += de_len;
	205	continue;
1da177e4 LT	206	}
	207
	208	map = 1;
	209	if (sbi->s_rock) {
	210	len = get_rock_ridge_filename(de, tmpname, inode);
	211	if (len != 0) { /* may be -1 */
	212	p = tmpname;
	213	map = 0;
	214	}
	215	}
	216	if (map) {
	217	#ifdef CONFIG_JOLIET
	218	if (sbi->s_joliet_level) {
	219	len = get_joliet_filename(de, tmpname, inode);
	220	p = tmpname;
	221	} else
	222	#endif
	223	if (sbi->s_mapping == 'a') {
	224	len = get_acorn_filename(de, tmpname, inode);
	225	p = tmpname;
	226	} else
	227	if (sbi->s_mapping == 'n') {
	228	len = isofs_name_translate(de, tmpname, inode);
	229	p = tmpname;
	230	} else {
	231	p = de->name;
	232	len = de->name_len[0];
	233	}
	234	}
	235	if (len > 0) {
	236	if (filldir(dirent, p, len, filp->f_pos, inode_number, DT_UNKNOWN) < 0)
	237	break;
	238	}
	239	filp->f_pos += de_len;
	240
	241	continue;
	242	}
	243	if (bh) brelse(bh);
	244	return 0;
	245	}
	246
	247	/*
	248	* Handle allocation of temporary space for name translation and
	249	* handling split directory entries.. The real work is done by
	250	* "do_isofs_readdir()".
	251	*/
	252	static int isofs_readdir(struct file *filp,
	253	void *dirent, filldir_t filldir)
	254	{
	255	int result;
	256	char * tmpname;
	257	struct iso_directory_record * tmpde;
2485822d	258	struct inode *inode = filp->f_path.dentry->d_inode;
1da177e4 LT	259
	260	tmpname = (char *)__get_free_page(GFP_KERNEL);
	261	if (tmpname == NULL)
	262	return -ENOMEM;
	263
	264	lock_kernel();
	265	tmpde = (struct iso_directory_record *) (tmpname+1024);
	266
	267	result = do_isofs_readdir(inode, filp, dirent, filldir, tmpname, tmpde);
	268
	269	free_page((unsigned long) tmpname);
	270	unlock_kernel();
	271	return result;
	272	}