patch-2.1.120 linux/fs/qnx4/namei.c

• Lines: 280
• Date: Tue Sep 1 10:43:13 1998
• Orig file: v2.1.119/linux/fs/qnx4/namei.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.119/linux/fs/qnx4/namei.c linux/fs/qnx4/namei.c
@@ -0,0 +1,279 @@
+/* 
+ * QNX4 file system, Linux implementation.
+ * 
+ * Version : 0.1
+ * 
+ * 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/config.h>
+#include <linux/sched.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 <asm/segment.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;
+
+	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 & 0x08) == 0x08) {
+		namelen = QNX4_NAME_MAX;
+	} else {
+		namelen = _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;
+	}
+	if (len != strlen(de->di_fname)) {
+		return 0;
+	}
+	if (strncmp(name, de->di_fname, len) == 0) {
+		if ((de->di_mode) || (de->di_status == QNX4_FILE_LINK)) {
+			if (de->di_status) {
+				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 || !dir->i_sb) {
+		if (!dir) {
+			printk("qnx4: NULL dir.\n");
+		} else {
+			printk("qnx4: no superblock on dir.\n");
+		}
+		return NULL;
+	}
+	bh = NULL;
+	blkofs = dir->u.qnx4_i.i_first_xtnt.xtnt_blk - 1;
+	offset = block = 0;
+	while (block * QNX4_BLOCK_SIZE + offset < dir->i_size) {
+		if (!bh) {
+			bh = qnx4_bread(dir, block + blkofs, 0);
+			if (!bh) {
+				block++;
+				continue;
+			}
+		}
+		*res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
+		if (qnx4_match(len, name, bh, &offset)) {
+			*ino = (block + blkofs) * QNX4_INODES_PER_BLOCK +
+			    (offset / QNX4_DIR_ENTRY_SIZE) - 1;
+			return bh;
+		}
+		if (offset < bh->b_size) {
+			continue;
+		}
+		brelse(bh);
+		bh = NULL;
+		offset = 0;
+		block++;
+	}
+	brelse(bh);
+	*res_dir = NULL;
+	return NULL;
+}
+
+int qnx4_lookup(struct inode *dir, struct dentry *dentry)
+{
+	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;
+
+	if (!dir) {
+		return -EBADF;
+	}
+	if (!S_ISDIR(dir->i_mode)) {
+		return -EBADF;
+	}
+	if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino))) {
+		return -ENOENT;
+	}
+	/* 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 = (lnk->dl_inode_blk - 1) * QNX4_INODES_PER_BLOCK +
+		    lnk->dl_inode_ndx;
+	}
+	brelse(bh);
+
+	if ((foundinode = iget(dir->i_sb, ino)) == NULL) {
+		QNX4DEBUG(("qnx4: lookup->iget -> NULL\n"));
+		return -EACCES;
+	}
+	d_add(dentry, foundinode);
+
+	return 0;
+}
+
+#ifdef CONFIG_QNX4FS_RW
+int qnx4_create(struct inode *dir, struct dentry *dentry, int mode)
+{
+	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));
+	bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
+			     &de, &ino);
+	if (bh == NULL) {
+		return -ENOENT;
+	}
+	if ((inode = iget(dir->i_sb, ino)) == NULL) {
+		QNX4DEBUG(("qnx4: lookup->iget -> NULL\n"));
+		retval = -EACCES;
+		goto end_rmdir;
+	}
+	retval = -EPERM;
+	if ((dir->i_mode & S_ISVTX) &&
+	    current->fsuid != inode->i_uid &&
+	    current->fsuid != dir->i_uid && !capable(CAP_FOWNER)) {
+		QNX4DEBUG(("qnx4: rmdir->capabilities\n"));
+		goto end_rmdir;
+	}
+	if (inode->i_dev != dir->i_dev) {
+		QNX4DEBUG(("qnx4: rmdir->different devices\n"));
+		goto end_rmdir;
+	}
+	if (inode == dir) {	/* we may not delete ".", but "../dir" is ok */
+		QNX4DEBUG(("qnx4: inode==dir\n"));
+		goto end_rmdir;
+	}
+	if (!S_ISDIR(inode->i_mode)) {
+		QNX4DEBUG(("qnx4: rmdir->not a directory\n"));
+		retval = -ENOTDIR;
+		goto end_rmdir;
+	}
+#if 0
+	if (!empty_dir(inode)) {
+		retval = -ENOTEMPTY;
+		goto end_rmdir;
+	}
+#endif
+	if (dentry->d_count > 1) {
+		retval = -EBUSY;
+		goto end_rmdir;
+	}
+	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, 1);
+	inode->i_nlink = 0;
+	mark_inode_dirty(inode);
+	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+	dir->i_nlink--;
+	mark_inode_dirty(dir);
+	d_delete(dentry);
+	retval = 0;
+
+      end_rmdir:
+	brelse(bh);
+
+	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));
+	bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
+			     &de, &ino);
+	if (bh == NULL) {
+		return -ENOENT;
+	}
+	if ((inode = iget(dir->i_sb, ino)) == NULL) {
+		QNX4DEBUG(("qnx4: lookup->iget -> NULL\n"));
+		retval = -EACCES;
+		goto end_unlink;
+	}
+	retval = -EPERM;
+	if (S_ISDIR(inode->i_mode)) {
+		goto end_unlink;
+	}
+	if ((dir->i_mode & S_ISVTX) &&
+	    current->fsuid != inode->i_uid &&
+	    current->fsuid != dir->i_uid && !capable(CAP_FOWNER)) {
+		goto end_unlink;
+	}
+	if (!inode->i_nlink) {
+		QNX4DEBUG(("Deleting nonexistent file (%s:%lu), %d\n",
+			   kdevname(inode->i_dev),
+			   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, 1);
+	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+	mark_inode_dirty(dir);
+	inode->i_nlink--;
+	inode->i_ctime = dir->i_ctime;
+	mark_inode_dirty(inode);
+	d_delete(dentry);
+	retval = 0;
+
+      end_unlink:
+	brelse(bh);
+
+	return retval;
+}
+#endif