patch-1.3.94 linux/fs/ufs/ufs_symlink.c

• Lines: 182
• Date: Mon Apr 22 10:59:39 1996
• Orig file: v1.3.93/linux/fs/ufs/ufs_symlink.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.93/linux/fs/ufs/ufs_symlink.c linux/fs/ufs/ufs_symlink.c
@@ -0,0 +1,181 @@
+/*
+ *  linux/fs/ufs/ufs_symlink.c
+ *
+ * Copyright (C) 1996
+ * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
+ * Laboratory for Computer Science Research Computing Facility
+ * Rutgers, The State University of New Jersey
+ *
+ * $Id: ufs_symlink.c,v 1.1 1996/04/21 14:41:23 davem Exp $
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/sched.h>
+
+static int
+ufs_readlink(struct inode * inode, char * buffer, int buflen)
+{
+	unsigned long int block;
+	struct buffer_head * bh = NULL;
+	char * link;
+	int i, err;
+	char c;
+
+	if (inode->i_sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_LINKS)) {
+	        printk("ufs_readlink: called on ino %lu dev %u/%u\n",
+	               inode->i_ino, MAJOR(inode->i_dev), MINOR(inode->i_dev));
+	}
+
+	if (!S_ISLNK(inode->i_mode)) {
+		iput (inode);
+		return -EINVAL;
+	}
+	if (buflen > inode->i_sb->s_blocksize - 1)
+		buflen = inode->i_sb->s_blocksize - 1;
+	if (inode->i_blocks) {
+	        /* XXX - error checking */
+	        block = ufs_bmap(inode, 0);
+	        if (inode->i_sb->u.ufs_sb.s_flags &(UFS_DEBUG|UFS_DEBUG_LINKS)) {
+	                printk("ufs_readlink: bmap got %lu for ino %lu\n",
+	                       block, inode->i_ino);
+} 
+	        bh = bread(inode->i_dev, block, BLOCK_SIZE);
+		if (!bh) {
+			iput (inode);
+	                printk("ufs_readlink: can't read block 0 for ino %lu on dev %u/%u\n",
+	                       inode->i_ino, MAJOR(inode->i_dev),
+	                       MINOR(inode->i_dev));
+			return 0;
+		}
+		link = bh->b_data;
+	}
+	else {
+	        link = (char *)&(inode->u.ufs_i.ui_db[0]);
+	}
+	i = 0;
+	while (i < buflen && (c = link[i])) {
+		i++;
+		put_user (c, buffer++);
+	}
+	iput (inode);
+	if (bh)
+		brelse (bh);
+	return i;
+
+	return(0);
+}
+
+/*
+ * XXX - blatantly stolen from ext2fs
+ */
+static int
+ufs_follow_link(struct inode * dir, struct inode * inode,
+	        int flag, int mode, struct inode ** res_inode)
+{
+	unsigned long int block;
+	int error;
+	struct buffer_head * bh;
+	char * link;
+
+	bh = NULL;
+
+	if (inode->i_sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_LINKS)) {
+	        printk("ufs_follow_link: called on ino %lu dev %u/%u\n",
+	               dir->i_ino, MAJOR(dir->i_dev), MINOR(dir->i_dev));
+	}
+
+	*res_inode = NULL;
+	if (!dir) {
+	        dir = current->fs->root;
+	        dir->i_count++;
+	}
+	if (!inode) {
+		iput (dir);
+		return -ENOENT;
+	}
+	if (!S_ISLNK(inode->i_mode)) {
+		iput (dir);
+		*res_inode = inode;
+		return 0;
+	}
+	if (current->link_count > 5) {
+		iput (dir);
+		iput (inode);
+		return -ELOOP;
+	}
+	if (inode->i_blocks) {
+	        /* read the link from disk */
+	        /* XXX - error checking */
+	        block = ufs_bmap(inode, 0);
+	        bh = bread(inode->i_dev, block, BLOCK_SIZE);
+	        if (bh == NULL) {
+	                printk("ufs_follow_link: can't read block 0 for ino %lu on dev %u/%u\n",
+	                       inode->i_ino, MAJOR(inode->i_dev),
+	                       MINOR(inode->i_dev));
+	                iput(dir);
+	                iput(inode);
+	                return(-EIO);
+	        }
+	        link = bh->b_data;
+	} else {
+	        /* fast symlink */
+	        link = (char *)&(inode->u.ufs_i.ui_db[0]);
+	}
+	current->link_count++;
+	error = open_namei (link, flag, mode, res_inode, dir);
+	current->link_count--;
+	iput (inode);
+	if (bh) {
+		brelse (bh);
+	}
+	return(error);
+}
+
+
+static struct file_operations ufs_symlink_operations = {
+	NULL,			/* lseek */
+	NULL,			/* read */
+	NULL,			/* write */
+	NULL,			/* readdir */
+	NULL,			/* select */
+	NULL,			/* ioctl */
+	NULL,			/* mmap */
+	NULL,			/* open */
+	NULL,			/* release */
+	NULL,			/* fsync */  /* XXX - is this ok? */
+	NULL,			/* fasync */
+	NULL,			/* check_media_change */
+	NULL,			/* revalidate */
+};
+
+struct inode_operations ufs_symlink_inode_operations = {
+	&ufs_symlink_operations,	/* default directory file operations */
+	NULL,			/* create */
+	NULL,			/* lookup */
+	NULL,			/* link */
+	NULL,			/* unlink */
+	NULL,			/* symlink */
+	NULL,			/* mkdir */
+	NULL,			/* rmdir */
+	NULL,			/* mknod */
+	NULL,			/* rename */
+	&ufs_readlink,		/* readlink */
+	&ufs_follow_link,	/* follow_link */
+	NULL,			/* readpage */
+	NULL,			/* writepage */
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL,			/* permission */
+	NULL,			/* smap */
+};
+
+/*
+ * Local Variables: ***
+ * c-indent-level: 8 ***
+ * c-continued-statement-offset: 8 ***
+ * c-brace-offset: -8 ***
+ * c-argdecl-indent: 0 ***
+ * c-label-offset: -8 ***
+ * End: ***
+ */