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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/freevxfs/vxfs_immed.c
Initial import
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diff --git a/fs/freevxfs/vxfs_immed.c b/fs/freevxfs/vxfs_immed.c
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+/*
+ * 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.
+ */
+
+/*
+ * Veritas filesystem driver - support for 'immed' inodes.
+ */
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/namei.h>
+
+#include "vxfs.h"
+#include "vxfs_extern.h"
+#include "vxfs_inode.h"
+
+
+static void * 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.
+ */
+const struct inode_operations vxfs_immed_symlink_iops = {
+ .readlink = generic_readlink,
+ .follow_link = vxfs_immed_follow_link,
+};
+
+/*
+ * Address space operations for immed files and directories.
+ */
+const struct address_space_operations vxfs_immed_aops = {
+ .readpage = vxfs_immed_readpage,
+};
+
+/**
+ * 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 void *
+vxfs_immed_follow_link(struct dentry *dp, struct nameidata *np)
+{
+ struct vxfs_inode_info *vip = VXFS_INO(d_inode(dp));
+ nd_set_link(np, vip->vii_immed.vi_immed);
+ return NULL;
+}
+
+/**
+ * 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 = (u_int64_t)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);
+ unlock_page(pp);
+
+ return 0;
+}