forked from luck/tmp_suning_uos_patched
754661f143
Many struct inode_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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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const 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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const 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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