patch-2.3.32 linux/fs/efs/symlink.c

• Lines: 133
• Date: Mon Dec 13 16:02:45 1999
• Orig file: v2.3.31/linux/fs/efs/symlink.c
• Orig date: Tue Dec 7 09:32:47 1999

diff -u --recursive --new-file v2.3.31/linux/fs/efs/symlink.c linux/fs/efs/symlink.c
@@ -7,97 +7,49 @@
  */
 
 #include <linux/string.h>
-#include <linux/malloc.h>
 #include <linux/efs_fs.h>
+#include <linux/pagemap.h>
 
-static int efs_readlink(struct dentry *, char *, int);
-static struct dentry * efs_follow_link(struct dentry *, struct dentry *, unsigned int);
-
-struct inode_operations efs_symlink_inode_operations = {
-	NULL,			/* no symlink file-operations */
-	NULL,			/* create */
-	NULL,			/* lookup */
-	NULL,			/* link */
-	NULL,			/* unlink */
-	NULL,			/* symlink */
-	NULL,			/* mkdir */
-	NULL,			/* rmdir */
-	NULL,			/* mknod */
-	NULL,			/* rename */
-	efs_readlink,		/* readlink */
-	efs_follow_link,	/* follow_link */
-	NULL,			/* get_block */
-	NULL,			/* readpage */
-	NULL,			/* writepage */
-	NULL,			/* truncate */
-	NULL,			/* permission */
-	NULL			/* revalidate */
-};
-
-static char *efs_linktarget(struct inode *in, int *len) {
-	char *name;
+static int efs_symlink_readpage(struct dentry *dentry, struct page *page)
+{
+	char *link = (char*)kmap(page);
 	struct buffer_head * bh;
-	efs_block_t size = in->i_size;
-  
-	if (size > 2 * EFS_BLOCKSIZE) {
-		printk(KERN_ERR "EFS: linktarget(): name too long: %lu\n", in->i_size);
-		return NULL;
-	}
-  
-	if (!(name = kmalloc(size + 1, GFP_KERNEL)))
-		return NULL;
+	struct inode * inode = dentry->d_inode;
+	efs_block_t size = inode->i_size;
+	int err;
+  
+	err = -ENAMETOOLONG;
+	if (size > 2 * EFS_BLOCKSIZE)
+		goto fail;
   
 	/* read first 512 bytes of link target */
-	bh = bread(in->i_dev, efs_bmap(in, 0), EFS_BLOCKSIZE);
-	if (!bh) {
-		kfree(name);
-		printk(KERN_ERR "EFS: linktarget(): couldn't read block %d\n", efs_bmap(in, 0));
-		return NULL;
-	}
-
-	memcpy(name, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size);
+	err = -EIO;
+	bh = bread(inode->i_dev, efs_bmap(inode, 0), EFS_BLOCKSIZE);
+	if (!bh)
+		goto fail;
+	memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size);
 	brelse(bh);
-
 	if (size > EFS_BLOCKSIZE) {
-		bh = bread(in->i_dev, efs_bmap(in, 1), EFS_BLOCKSIZE);
-		if (!bh) {
-			kfree(name);
-			printk(KERN_ERR "EFS: linktarget(): couldn't read block %d\n", efs_bmap(in, 1));
-			return NULL;
-		}
-		memcpy(name + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE);
+		bh = bread(inode->i_dev, efs_bmap(inode, 1), EFS_BLOCKSIZE);
+		if (!bh)
+			goto fail;
+		memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE);
 		brelse(bh);
 	}
-  
-	name[size] = (char) 0;
-	if (len) *len = size;
-
-	return name;
-}
-
-static struct dentry *efs_follow_link(struct dentry *dentry, struct dentry *base, unsigned int follow) {
-	char *name;
-	struct inode *inode = dentry->d_inode;
-
-	if (!(name = efs_linktarget(inode, NULL))) {
-		dput(base);
-		return ERR_PTR(-ELOOP);
-	}
-	base = lookup_dentry(name, base, follow);
-	kfree(name);
-  
-	return base;
-}
-
-static int efs_readlink(struct dentry * dir, char * buf, int bufsiz) {
-	int rc;
-	char *name;
-	struct inode *inode = dir->d_inode;
-  
-	if (!(name = efs_linktarget(inode, &bufsiz))) return 0;
-	rc = copy_to_user(buf, name, bufsiz) ? -EFAULT : bufsiz;
-	kfree(name);
-
-	return rc;
+	link[size] = '\0';
+	SetPageUptodate(page);
+	kunmap(page);
+	UnlockPage(page);
+	return 0;
+fail:
+	SetPageError(page);
+	kunmap(page);
+	UnlockPage(page);
+	return err;
 }
 
+struct inode_operations efs_symlink_inode_operations = {
+	readlink:	page_readlink,
+	follow_link:	page_follow_link,
+	readpage:	efs_symlink_readpage
+};