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