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

/*
 * dir.c
 *
 * PURPOSE
 *  Directory handling routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *	This file is distributed under the terms of the GNU General Public
 *	License (GPL). Copies of the GPL can be obtained from:
 *		ftp://prep.ai.mit.edu/pub/gnu/GPL
 *	Each contributing author retains all rights to their own work.
 *
 *  (C) 1998-2004 Ben Fennema
 *
 * HISTORY
 *
 *  10/05/98 dgb  Split directory operations into its own file
 *                Implemented directory reads via do_udf_readdir
 *  10/06/98      Made directory operations work!
 *  11/17/98      Rewrote directory to support ICBTAG_FLAG_AD_LONG
 *  11/25/98 blf  Rewrote directory handling (readdir+lookup) to support reading
 *                across blocks.
 *  12/12/98      Split out the lookup code to namei.c. bulk of directory
 *                code now in directory.c:udf_fileident_read.
 */

#include "udfdecl.h"

#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>

#include "udf_i.h"
#include "udf_sb.h"

/* Prototypes for file operations */
static int udf_readdir(struct file *, void *, filldir_t);
static int do_udf_readdir(struct inode *, struct file *, filldir_t, void *);

/* readdir and lookup functions */

const struct file_operations udf_dir_operations = {
	.read			= generic_read_dir,
	.readdir		= udf_readdir,
	.ioctl			= udf_ioctl,
	.fsync			= udf_fsync_file,
};

/*
 * udf_readdir
 *
 * PURPOSE
 *	Read a directory entry.
 *
 * DESCRIPTION
 *	Optional - sys_getdents() will return -ENOTDIR if this routine is not
 *	available.
 *
 *	Refer to sys_getdents() in fs/readdir.c
 *	sys_getdents() -> .
 *
 * PRE-CONDITIONS
 *	filp			Pointer to directory file.
 *	buf			Pointer to directory entry buffer.
 *	filldir			Pointer to filldir function.
 *
 * POST-CONDITIONS
 *	<return>		>=0 on success.
 *
 * HISTORY
 *	July 1, 1997 - Andrew E. Mileski
 *	Written, tested, and released.
 */

int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct inode *dir = filp->f_path.dentry->d_inode;
	int result;

	lock_kernel();

	if (filp->f_pos == 0) {
		if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) {
			unlock_kernel();
			return 0;
		}
		filp->f_pos++;
	}

	result = do_udf_readdir(dir, filp, filldir, dirent);
	unlock_kernel();
 	return result;
}

static int
do_udf_readdir(struct inode *dir, struct file *filp, filldir_t filldir,
	       void *dirent)
{
	struct udf_fileident_bh fibh;
	struct fileIdentDesc *fi = NULL;
	struct fileIdentDesc cfi;
	int block, iblock;
	loff_t nf_pos = filp->f_pos - 1;
	int flen;
	char fname[UDF_NAME_LEN];
	char *nameptr;
	uint16_t liu;
	uint8_t lfi;
	loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2;
	struct buffer_head *tmp, *bha[16];
	kernel_lb_addr eloc;
	uint32_t elen;
	sector_t offset;
	int i, num;
	unsigned int dt_type;
	struct extent_position epos = { NULL, 0, {0, 0} };

	if (nf_pos >= size)
		return 0;

	if (nf_pos == 0)
		nf_pos = (udf_ext0_offset(dir) >> 2);

	fibh.soffset = fibh.eoffset = (nf_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;
	if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) {
		fibh.sbh = fibh.ebh = NULL;
	} else if (inode_bmap(dir, nf_pos >> (dir->i_sb->s_blocksize_bits - 2),
			      &epos, &eloc, &elen, &offset) == (EXT_RECORDED_ALLOCATED >> 30)) {
		block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
		if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
			if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT)
				epos.offset -= sizeof(short_ad);
			else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG)
				epos.offset -= sizeof(long_ad);
		} else {
			offset = 0;
		}

		if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) {
			brelse(epos.bh);
			return -EIO;
		}

		if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) {
			i = 16 >> (dir->i_sb->s_blocksize_bits - 9);
			if (i + offset > (elen >> dir->i_sb->s_blocksize_bits))
				i = (elen >> dir->i_sb->s_blocksize_bits) - offset;
			for (num = 0; i > 0; i--) {
				block = udf_get_lb_pblock(dir->i_sb, eloc, offset + i);
				tmp = udf_tgetblk(dir->i_sb, block);
				if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
					bha[num++] = tmp;
				else
					brelse(tmp);
			}
			if (num) {
				ll_rw_block(READA, num, bha);
				for (i = 0; i < num; i++)
					brelse(bha[i]);
			}
		}
	} else {
		brelse(epos.bh);
		return -ENOENT;
	}

	while (nf_pos < size) {
		filp->f_pos = nf_pos + 1;

		fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
					&elen, &offset);
		if (!fi) {
			if (fibh.sbh != fibh.ebh)
				brelse(fibh.ebh);
			brelse(fibh.sbh);
			brelse(epos.bh);
			return 0;
		}

		liu = le16_to_cpu(cfi.lengthOfImpUse);
		lfi = cfi.lengthFileIdent;

		if (fibh.sbh == fibh.ebh) {
			nameptr = fi->fileIdent + liu;
		} else {
			int poffset;	/* Unpaded ending offset */

			poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;

			if (poffset >= lfi) {
				nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
			} else {
				nameptr = fname;
				memcpy(nameptr, fi->fileIdent + liu,
				       lfi - poffset);
				memcpy(nameptr + lfi - poffset,
				       fibh.ebh->b_data, poffset);
			}
		}

		if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
			if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE))
				continue;
		}

		if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
			if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE))
				continue;
		}

		if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
			iblock = parent_ino(filp->f_path.dentry);
			flen = 2;
			memcpy(fname, "..", flen);
			dt_type = DT_DIR;
		} else {
			kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation);

			iblock = udf_get_lb_pblock(dir->i_sb, tloc, 0);
			flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
			dt_type = DT_UNKNOWN;
		}

		if (flen) {
			if (filldir(dirent, fname, flen, filp->f_pos, iblock, dt_type) < 0) {
				if (fibh.sbh != fibh.ebh)
					brelse(fibh.ebh);
				brelse(fibh.sbh);
				brelse(epos.bh);
	 			return 0;
			}
		}
	} /* end while */

	filp->f_pos = nf_pos + 1;

	if (fibh.sbh != fibh.ebh)
		brelse(fibh.ebh);
	brelse(fibh.sbh);
	brelse(epos.bh);

	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* dir.c
	3	*
	4	* PURPOSE
	5	* Directory handling routines for the OSTA-UDF(tm) filesystem.
	6	*
1da177e4 LT	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
4b6f5d20	45	const struct file_operations udf_dir_operations = {
28de7948 CG	46	.read = generic_read_dir,
	47	.readdir = udf_readdir,
	48	.ioctl = udf_ioctl,
	49	.fsync = udf_fsync_file,
1da177e4 LT	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	{
5096e933	80	struct inode *dir = filp->f_path.dentry->d_inode;
1da177e4 LT	81	int result;
	82
	83	lock_kernel();
	84
cb00ea35	85	if (filp->f_pos == 0) {
28de7948	86	if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) {
1da177e4 LT	87	unlock_kernel();
	88	return 0;
	89	}
cb00ea35	90	filp->f_pos++;
1da177e4 LT	91	}
	92
	93	result = do_udf_readdir(dir, filp, filldir, dirent);
	94	unlock_kernel();
28de7948	95	return result;
1da177e4 LT	96	}
1da177e4 LT	97
cb00ea35 CG	98	static int
	99	do_udf_readdir(struct inode dir, struct file filp, filldir_t filldir,
	100	void *dirent)
1da177e4 LT	101	{
1da177e4 LT	102	struct udf_fileident_bh fibh;
cb00ea35	103	struct fileIdentDesc *fi = NULL;
1da177e4 LT	104	struct fileIdentDesc cfi;
	105	int block, iblock;
	106	loff_t nf_pos = filp->f_pos - 1;
	107	int flen;
	108	char fname[UDF_NAME_LEN];
	109	char *nameptr;
	110	uint16_t liu;
	111	uint8_t lfi;
	112	loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2;
ff116fc8 JK	113	struct buffer_head tmp, bha[16];
	114	kernel_lb_addr eloc;
	115	uint32_t elen;
60448b1d	116	sector_t offset;
1da177e4 LT	117	int i, num;
1da177e4 LT	118	unsigned int dt_type;
cb00ea35	119	struct extent_position epos = { NULL, 0, {0, 0} };
1da177e4 LT	120
	121	if (nf_pos >= size)
	122	return 0;
	123
	124	if (nf_pos == 0)
	125	nf_pos = (udf_ext0_offset(dir) >> 2);
	126
28de7948 CG	127	fibh.soffset = fibh.eoffset = (nf_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;
28de7948 CG	128	if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) {
1da177e4	129	fibh.sbh = fibh.ebh = NULL;
28de7948 CG	130	} else if (inode_bmap(dir, nf_pos >> (dir->i_sb->s_blocksize_bits - 2),
28de7948 CG	131	&epos, &eloc, &elen, &offset) == (EXT_RECORDED_ALLOCATED >> 30)) {
1da177e4	132	block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
cb00ea35	133	if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
1da177e4	134	if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT)
ff116fc8	135	epos.offset -= sizeof(short_ad);
1da177e4	136	else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG)
ff116fc8	137	epos.offset -= sizeof(long_ad);
28de7948	138	} else {
1da177e4	139	offset = 0;
28de7948	140	}
1da177e4	141
cb00ea35	142	if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) {
3bf25cb4	143	brelse(epos.bh);
1da177e4 LT	144	return -EIO;
1da177e4 LT	145	}
cb00ea35 CG	146
cb00ea35 CG	147	if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) {
1da177e4	148	i = 16 >> (dir->i_sb->s_blocksize_bits - 9);
cb00ea35	149	if (i + offset > (elen >> dir->i_sb->s_blocksize_bits))
28de7948	150	i = (elen >> dir->i_sb->s_blocksize_bits) - offset;
cb00ea35	151	for (num = 0; i > 0; i--) {
28de7948	152	block = udf_get_lb_pblock(dir->i_sb, eloc, offset + i);
1da177e4	153	tmp = udf_tgetblk(dir->i_sb, block);
28de7948	154	if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
1da177e4 LT	155	bha[num++] = tmp;
	156	else
	157	brelse(tmp);
	158	}
cb00ea35	159	if (num) {
1da177e4	160	ll_rw_block(READA, num, bha);
cb00ea35	161	for (i = 0; i < num; i++)
1da177e4 LT	162	brelse(bha[i]);
	163	}
	164	}
cb00ea35	165	} else {
3bf25cb4	166	brelse(epos.bh);
1da177e4 LT	167	return -ENOENT;
	168	}
	169
cb00ea35	170	while (nf_pos < size) {
1da177e4 LT	171	filp->f_pos = nf_pos + 1;
1da177e4 LT	172
cb00ea35 CG	173	fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
cb00ea35 CG	174	&elen, &offset);
cb00ea35	175	if (!fi) {
1da177e4	176	if (fibh.sbh != fibh.ebh)
3bf25cb4 JK	177	brelse(fibh.ebh);
	178	brelse(fibh.sbh);
	179	brelse(epos.bh);
1da177e4 LT	180	return 0;
	181	}
	182
	183	liu = le16_to_cpu(cfi.lengthOfImpUse);
	184	lfi = cfi.lengthFileIdent;
	185
28de7948	186	if (fibh.sbh == fibh.ebh) {
1da177e4	187	nameptr = fi->fileIdent + liu;
28de7948	188	} else {
1da177e4 LT	189	int poffset; /* Unpaded ending offset */
1da177e4 LT	190
28de7948	191	poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
1da177e4	192
28de7948 CG	193	if (poffset >= lfi) {
	194	nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
	195	} else {
1da177e4	196	nameptr = fname;
cb00ea35 CG	197	memcpy(nameptr, fi->fileIdent + liu,
	198	lfi - poffset);
	199	memcpy(nameptr + lfi - poffset,
	200	fibh.ebh->b_data, poffset);
1da177e4 LT	201	}
	202	}
	203
cb00ea35 CG	204	if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
cb00ea35 CG	205	if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE))
1da177e4 LT	206	continue;
1da177e4 LT	207	}
cb00ea35 CG	208
	209	if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
	210	if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE))
1da177e4 LT	211	continue;
	212	}
	213
cb00ea35	214	if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
5096e933	215	iblock = parent_ino(filp->f_path.dentry);
1da177e4 LT	216	flen = 2;
	217	memcpy(fname, "..", flen);
	218	dt_type = DT_DIR;
cb00ea35	219	} else {
1da177e4 LT	220	kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation);
	221
	222	iblock = udf_get_lb_pblock(dir->i_sb, tloc, 0);
	223	flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
	224	dt_type = DT_UNKNOWN;
	225	}
	226
cb00ea35	227	if (flen) {
28de7948	228	if (filldir(dirent, fname, flen, filp->f_pos, iblock, dt_type) < 0) {
1da177e4	229	if (fibh.sbh != fibh.ebh)
3bf25cb4 JK	230	brelse(fibh.ebh);
	231	brelse(fibh.sbh);
	232	brelse(epos.bh);
28de7948	233	return 0;
1da177e4 LT	234	}
1da177e4 LT	235	}
28de7948	236	} /* end while */
1da177e4 LT	237
	238	filp->f_pos = nf_pos + 1;
	239
	240	if (fibh.sbh != fibh.ebh)
3bf25cb4 JK	241	brelse(fibh.ebh);
	242	brelse(fibh.sbh);
	243	brelse(epos.bh);
1da177e4 LT	244
	245	return 0;
	246	}