[linux.git] / fs / qnx4 / namei.c

/* 
 * QNX4 file system, Linux implementation.
 * 
 * Version : 0.2.1
 * 
 * Using parts of the xiafs filesystem.
 * 
 * History :
 * 
 * 01-06-1998 by Richard Frowijn : first release.
 * 21-06-1998 by Frank Denis : dcache support, fixed error codes.
 * 04-07-1998 by Frank Denis : first step for rmdir/unlink.
 */

#include <linux/time.h>
#include <linux/fs.h>
#include <linux/qnx4_fs.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>


/*
 * check if the filename is correct. For some obscure reason, qnx writes a
 * new file twice in the directory entry, first with all possible options at 0
 * and for a second time the way it is, they want us not to access the qnx
 * filesystem when whe are using linux.
 */
static int qnx4_match(int len, const char *name,
		      struct buffer_head *bh, unsigned long *offset)
{
	struct qnx4_inode_entry *de;
	int namelen, thislen;

	if (bh == NULL) {
		printk("qnx4: matching unassigned buffer !\n");
		return 0;
	}
	de = (struct qnx4_inode_entry *) (bh->b_data + *offset);
	*offset += QNX4_DIR_ENTRY_SIZE;
	if ((de->di_status & QNX4_FILE_LINK) != 0) {
		namelen = QNX4_NAME_MAX;
	} else {
		namelen = QNX4_SHORT_NAME_MAX;
	}
	/* "" means "." ---> so paths like "/usr/lib//libc.a" work */
	if (!len && (de->di_fname[0] == '.') && (de->di_fname[1] == '\0')) {
		return 1;
	}
	thislen = strlen( de->di_fname );
	if ( thislen > namelen )
		thislen = namelen;
	if (len != thislen) {
		return 0;
	}
	if (strncmp(name, de->di_fname, len) == 0) {
		if ((de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)) != 0) {
			return 1;
		}
	}
	return 0;
}

static struct buffer_head *qnx4_find_entry(int len, struct inode *dir,
	   const char *name, struct qnx4_inode_entry **res_dir, int *ino)
{
	unsigned long block, offset, blkofs;
	struct buffer_head *bh;

	*res_dir = NULL;
	if (!dir->i_sb) {
		printk("qnx4: no superblock on dir.\n");
		return NULL;
	}
	bh = NULL;
	block = offset = blkofs = 0;
	while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
		if (!bh) {
			bh = qnx4_bread(dir, blkofs, 0);
			if (!bh) {
				blkofs++;
				continue;
			}
		}
		*res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
		if (qnx4_match(len, name, bh, &offset)) {
			block = qnx4_block_map( dir, blkofs );
			*ino = block * QNX4_INODES_PER_BLOCK +
			    (offset / QNX4_DIR_ENTRY_SIZE) - 1;
			return bh;
		}
		if (offset < bh->b_size) {
			continue;
		}
		brelse(bh);
		bh = NULL;
		offset = 0;
		blkofs++;
	}
	brelse(bh);
	*res_dir = NULL;
	return NULL;
}

struct dentry * qnx4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
	int ino;
	struct qnx4_inode_entry *de;
	struct qnx4_link_info *lnk;
	struct buffer_head *bh;
	const char *name = dentry->d_name.name;
	int len = dentry->d_name.len;
	struct inode *foundinode = NULL;

	lock_kernel();
	if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino)))
		goto out;
	/* The entry is linked, let's get the real info */
	if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) {
		lnk = (struct qnx4_link_info *) de;
		ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) *
                    QNX4_INODES_PER_BLOCK +
		    lnk->dl_inode_ndx;
	}
	brelse(bh);

	if ((foundinode = iget(dir->i_sb, ino)) == NULL) {
		unlock_kernel();
		QNX4DEBUG(("qnx4: lookup->iget -> NULL\n"));
		return ERR_PTR(-EACCES);
	}
out:
	unlock_kernel();
	d_add(dentry, foundinode);

	return NULL;
}

#ifdef CONFIG_QNX4FS_RW
int qnx4_create(struct inode *dir, struct dentry *dentry, int mode,
		struct nameidata *nd)
{
	QNX4DEBUG(("qnx4: qnx4_create\n"));
	if (dir == NULL) {
		return -ENOENT;
	}
	return -ENOSPC;
}

int qnx4_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct buffer_head *bh;
	struct qnx4_inode_entry *de;
	struct inode *inode;
	int retval;
	int ino;

	QNX4DEBUG(("qnx4: qnx4_rmdir [%s]\n", dentry->d_name.name));
	lock_kernel();
	bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
			     &de, &ino);
	if (bh == NULL) {
		unlock_kernel();
		return -ENOENT;
	}
	inode = dentry->d_inode;
	if (inode->i_ino != ino) {
		retval = -EIO;
		goto end_rmdir;
	}
#if 0
	if (!empty_dir(inode)) {
		retval = -ENOTEMPTY;
		goto end_rmdir;
	}
#endif
	if (inode->i_nlink != 2) {
		QNX4DEBUG(("empty directory has nlink!=2 (%d)\n", inode->i_nlink));
	}
	QNX4DEBUG(("qnx4: deleting directory\n"));
	de->di_status = 0;
	memset(de->di_fname, 0, sizeof de->di_fname);
	de->di_mode = 0;
	mark_buffer_dirty(bh);
	clear_nlink(inode);
	mark_inode_dirty(inode);
	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
	inode_dec_link_count(dir);
	retval = 0;

      end_rmdir:
	brelse(bh);

	unlock_kernel();
	return retval;
}

int qnx4_unlink(struct inode *dir, struct dentry *dentry)
{
	struct buffer_head *bh;
	struct qnx4_inode_entry *de;
	struct inode *inode;
	int retval;
	int ino;

	QNX4DEBUG(("qnx4: qnx4_unlink [%s]\n", dentry->d_name.name));
	lock_kernel();
	bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
			     &de, &ino);
	if (bh == NULL) {
		unlock_kernel();
		return -ENOENT;
	}
	inode = dentry->d_inode;
	if (inode->i_ino != ino) {
		retval = -EIO;
		goto end_unlink;
	}
	retval = -EPERM;
	if (!inode->i_nlink) {
		QNX4DEBUG(("Deleting nonexistent file (%s:%lu), %d\n",
			   inode->i_sb->s_id,
			   inode->i_ino, inode->i_nlink));
		inode->i_nlink = 1;
	}
	de->di_status = 0;
	memset(de->di_fname, 0, sizeof de->di_fname);
	de->di_mode = 0;
	mark_buffer_dirty(bh);
	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
	mark_inode_dirty(dir);
	inode->i_ctime = dir->i_ctime;
	inode_dec_link_count(inode);
	retval = 0;

end_unlink:
	unlock_kernel();
	brelse(bh);

	return retval;
}
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* QNX4 file system, Linux implementation.
	3	*
	4	* Version : 0.2.1
	5	*
	6	* Using parts of the xiafs filesystem.
	7	*
	8	* History :
	9	*
	10	* 01-06-1998 by Richard Frowijn : first release.
	11	* 21-06-1998 by Frank Denis : dcache support, fixed error codes.
	12	* 04-07-1998 by Frank Denis : first step for rmdir/unlink.
	13	*/
	14
1da177e4 LT	15	#include <linux/time.h>
	16	#include <linux/fs.h>
	17	#include <linux/qnx4_fs.h>
	18	#include <linux/kernel.h>
	19	#include <linux/string.h>
	20	#include <linux/stat.h>
	21	#include <linux/fcntl.h>
	22	#include <linux/errno.h>
	23	#include <linux/smp_lock.h>
	24	#include <linux/buffer_head.h>
	25
	26
	27	/*
	28	* check if the filename is correct. For some obscure reason, qnx writes a
	29	* new file twice in the directory entry, first with all possible options at 0
	30	* and for a second time the way it is, they want us not to access the qnx
	31	* filesystem when whe are using linux.
	32	*/
	33	static int qnx4_match(int len, const char *name,
	34	struct buffer_head bh, unsigned long offset)
	35	{
	36	struct qnx4_inode_entry *de;
	37	int namelen, thislen;
	38
	39	if (bh == NULL) {
	40	printk("qnx4: matching unassigned buffer !\n");
	41	return 0;
	42	}
	43	de = (struct qnx4_inode_entry ) (bh->b_data + offset);
	44	*offset += QNX4_DIR_ENTRY_SIZE;
	45	if ((de->di_status & QNX4_FILE_LINK) != 0) {
	46	namelen = QNX4_NAME_MAX;
	47	} else {
	48	namelen = QNX4_SHORT_NAME_MAX;
	49	}
	50	/* "" means "." ---> so paths like "/usr/lib//libc.a" work */
	51	if (!len && (de->di_fname[0] == '.') && (de->di_fname[1] == '\0')) {
	52	return 1;
	53	}
	54	thislen = strlen( de->di_fname );
	55	if ( thislen > namelen )
	56	thislen = namelen;
	57	if (len != thislen) {
	58	return 0;
	59	}
	60	if (strncmp(name, de->di_fname, len) == 0) {
	61	if ((de->di_status & (QNX4_FILE_USED\|QNX4_FILE_LINK)) != 0) {
	62	return 1;
	63	}
	64	}
	65	return 0;
	66	}
	67
	68	static struct buffer_head qnx4_find_entry(int len, struct inode dir,
	69	const char name, struct qnx4_inode_entry res_dir, int ino)
	70	{
	71	unsigned long block, offset, blkofs;
	72	struct buffer_head *bh;
	73
	74	*res_dir = NULL;
	75	if (!dir->i_sb) {
	76	printk("qnx4: no superblock on dir.\n");
	77	return NULL;
	78	}
79	bh = NULL;
80	block = offset = blkofs = 0;
81	while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
82	if (!bh) {
83	bh = qnx4_bread(dir, blkofs, 0);
84	if (!bh) {
85	blkofs++;
86	continue;
87	}
88	}
89	res_dir = (struct qnx4_inode_entry ) (bh->b_data + offset);
90	if (qnx4_match(len, name, bh, &offset)) {
91	block = qnx4_block_map( dir, blkofs );
92	ino = block QNX4_INODES_PER_BLOCK +
93	(offset / QNX4_DIR_ENTRY_SIZE) - 1;
94	return bh;
95	}
96	if (offset < bh->b_size) {
97	continue;
98	}
99	brelse(bh);
100	bh = NULL;
101	offset = 0;
102	blkofs++;
103	}
104	brelse(bh);
105	*res_dir = NULL;
106	return NULL;
107	}
108
109	struct dentry * qnx4_lookup(struct inode dir, struct dentry dentry, struct nameidata *nd)
110	{
111	int ino;
112	struct qnx4_inode_entry *de;
113	struct qnx4_link_info *lnk;
114	struct buffer_head *bh;
115	const char *name = dentry->d_name.name;
116	int len = dentry->d_name.len;
117	struct inode *foundinode = NULL;
118
119	lock_kernel();
120	if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino)))
121	goto out;
122	/* The entry is linked, let's get the real info */
123	if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) {
124	lnk = (struct qnx4_link_info *) de;
125	ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) *
126	QNX4_INODES_PER_BLOCK +
127	lnk->dl_inode_ndx;
128	}
129	brelse(bh);
130
131	if ((foundinode = iget(dir->i_sb, ino)) == NULL) {
132	unlock_kernel();
133	QNX4DEBUG(("qnx4: lookup->iget -> NULL\n"));
134	return ERR_PTR(-EACCES);
135	}
136	out:
137	unlock_kernel();
138	d_add(dentry, foundinode);
139
140	return NULL;
141	}
142
143	#ifdef CONFIG_QNX4FS_RW
144	int qnx4_create(struct inode dir, struct dentry dentry, int mode,
145	struct nameidata *nd)
146	{
147	QNX4DEBUG(("qnx4: qnx4_create\n"));
148	if (dir == NULL) {
149	return -ENOENT;
150	}
151	return -ENOSPC;
152	}
153
154	int qnx4_rmdir(struct inode dir, struct dentry dentry)
155	{
156	struct buffer_head *bh;
157	struct qnx4_inode_entry *de;
158	struct inode *inode;
159	int retval;
160	int ino;
161
162	QNX4DEBUG(("qnx4: qnx4_rmdir [%s]\n", dentry->d_name.name));
163	lock_kernel();
164	bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
165	&de, &ino);
166	if (bh == NULL) {
167	unlock_kernel();
168	return -ENOENT;
169	}
170	inode = dentry->d_inode;
171	if (inode->i_ino != ino) {
172	retval = -EIO;
173	goto end_rmdir;
174	}
175	#if 0
176	if (!empty_dir(inode)) {
177	retval = -ENOTEMPTY;
178	goto end_rmdir;
179	}
180	#endif
181	if (inode->i_nlink != 2) {
182	QNX4DEBUG(("empty directory has nlink!=2 (%d)\n", inode->i_nlink));
183	}
184	QNX4DEBUG(("qnx4: deleting directory\n"));
185	de->di_status = 0;
186	memset(de->di_fname, 0, sizeof de->di_fname);
187	de->di_mode = 0;
188	mark_buffer_dirty(bh);
ce71ec36	189	clear_nlink(inode);
1da177e4 LT	190	mark_inode_dirty(inode);
1da177e4 LT	191	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
9a53c3a7	192	inode_dec_link_count(dir);
1da177e4 LT	193	retval = 0;
	194
	195	end_rmdir:
	196	brelse(bh);
	197
	198	unlock_kernel();
	199	return retval;
	200	}
	201
	202	int qnx4_unlink(struct inode dir, struct dentry dentry)
	203	{
	204	struct buffer_head *bh;
	205	struct qnx4_inode_entry *de;
	206	struct inode *inode;
	207	int retval;
	208	int ino;
	209
	210	QNX4DEBUG(("qnx4: qnx4_unlink [%s]\n", dentry->d_name.name));
	211	lock_kernel();
	212	bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
	213	&de, &ino);
	214	if (bh == NULL) {
	215	unlock_kernel();
	216	return -ENOENT;
	217	}
	218	inode = dentry->d_inode;
	219	if (inode->i_ino != ino) {
	220	retval = -EIO;
	221	goto end_unlink;
	222	}
	223	retval = -EPERM;
	224	if (!inode->i_nlink) {
	225	QNX4DEBUG(("Deleting nonexistent file (%s:%lu), %d\n",
	226	inode->i_sb->s_id,
	227	inode->i_ino, inode->i_nlink));
	228	inode->i_nlink = 1;
	229	}
	230	de->di_status = 0;
	231	memset(de->di_fname, 0, sizeof de->di_fname);
	232	de->di_mode = 0;
	233	mark_buffer_dirty(bh);
	234	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
	235	mark_inode_dirty(dir);
1da177e4	236	inode->i_ctime = dir->i_ctime;
9a53c3a7	237	inode_dec_link_count(inode);
1da177e4 LT	238	retval = 0;
	239
	240	end_unlink:
	241	unlock_kernel();
	242	brelse(bh);
	243
	244	return retval;
	245	}
	246	#endif