patch-2.4.5 linux/fs/freevxfs/vxfs_immed.c

• Lines: 139
• Date: Mon May 21 12:31:06 2001
• Orig file: v2.4.4/linux/fs/freevxfs/vxfs_immed.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.4/linux/fs/freevxfs/vxfs_immed.c linux/fs/freevxfs/vxfs_immed.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2000-2001 Christoph Hellwig.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL").
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ident "$Id: vxfs_immed.c,v 1.10 2001/04/25 18:11:23 hch Exp hch $"
+
+/*
+ * Veritas filesystem driver - support for 'immed' inodes.
+ */
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+
+#include "vxfs.h"
+#include "vxfs_inode.h"
+
+
+static int	vxfs_immed_readlink(struct dentry *, char *, int);
+static int	vxfs_immed_follow_link(struct dentry *, struct nameidata *);
+
+static int	vxfs_immed_readpage(struct file *, struct page *);
+
+/*
+ * Inode operations for immed symlinks.
+ *
+ * Unliked all other operations we do not go through the pagecache,
+ * but do all work directly on the inode.
+ */
+struct inode_operations vxfs_immed_symlink_iops = {
+	.readlink =		vxfs_immed_readlink,
+	.follow_link =		vxfs_immed_follow_link,
+};
+
+/*
+ * Adress space operations for immed files and directories.
+ */
+struct address_space_operations vxfs_immed_aops = {
+	.readpage =		vxfs_immed_readpage,
+};
+
+
+/**
+ * vxfs_immed_readlink - read immed symlink
+ * @dp:		dentry for the link
+ * @bp:		output buffer
+ * @buflen:	length of @bp
+ *
+ * Description:
+ *   vxfs_immed_readlink calls vfs_readlink to read the link
+ *   described by @dp into userspace.
+ *
+ * Returns:
+ *   Number of bytes successfully copied to userspace.
+ */
+static int
+vxfs_immed_readlink(struct dentry *dp, char *bp, int buflen)
+{
+	struct vxfs_inode_info		*vip = VXFS_INO(dp->d_inode);
+
+	return (vfs_readlink(dp, bp, buflen, vip->vii_immed.vi_immed));
+}
+
+/**
+ * vxfs_immed_follow_link - follow immed symlink
+ * @dp:		dentry for the link
+ * @np:		pathname lookup data for the current path walk
+ *
+ * Description:
+ *   vxfs_immed_follow_link restarts the pathname lookup with
+ *   the data obtained from @dp.
+ *
+ * Returns:
+ *   Zero on success, else a negative error code.
+ */
+static int
+vxfs_immed_follow_link(struct dentry *dp, struct nameidata *np)
+{
+	struct vxfs_inode_info		*vip = VXFS_INO(dp->d_inode);
+
+	return (vfs_follow_link(np, vip->vii_immed.vi_immed));
+}
+
+/**
+ * vxfs_immed_readpage - read part of an immed inode into pagecache
+ * @file:	file context (unused)
+ * @page:	page frame to fill in.
+ *
+ * Description:
+ *   vxfs_immed_readpage reads a part of the immed area of the
+ *   file that hosts @pp into the pagecache.
+ *
+ * Returns:
+ *   Zero on success, else a negative error code.
+ *
+ * Locking status:
+ *   @page is locked and will be unlocked.
+ */
+static int
+vxfs_immed_readpage(struct file *fp, struct page *pp)
+{
+	struct vxfs_inode_info	*vip = VXFS_INO(pp->mapping->host);
+	u_int64_t		offset = pp->index << PAGE_CACHE_SHIFT;
+	caddr_t			kaddr;
+
+	kaddr = kmap(pp);
+	memcpy(kaddr, vip->vii_immed.vi_immed + offset, PAGE_CACHE_SIZE);
+	kunmap(pp);
+	
+	flush_dcache_page(pp);
+	SetPageUptodate(pp);
+        UnlockPage(pp);
+
+	return 0;
+}