44b11874ff
Separate out the function of revalidating the inode metadata, and revalidating the mapping. The former may be called by lookup(), and only really needs to check that permissions, ctime, etc haven't changed whereas the latter needs only done when we want to read data from the page cache, and may need to sync and then invalidate the mapping. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
97 lines
2 KiB
C
97 lines
2 KiB
C
/*
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* linux/fs/nfs/symlink.c
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*
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* Copyright (C) 1992 Rick Sladkey
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*
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* Optimization changes Copyright (C) 1994 Florian La Roche
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*
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* Jun 7 1999, cache symlink lookups in the page cache. -DaveM
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*
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* nfs symlink handling code
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*/
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#define NFS_NEED_XDR_TYPES
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#include <linux/time.h>
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#include <linux/errno.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/nfs.h>
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#include <linux/nfs2.h>
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#include <linux/nfs_fs.h>
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#include <linux/pagemap.h>
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#include <linux/stat.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/smp_lock.h>
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#include <linux/namei.h>
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/* Symlink caching in the page cache is even more simplistic
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* and straight-forward than readdir caching.
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*/
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static int nfs_symlink_filler(struct inode *inode, struct page *page)
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{
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int error;
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lock_kernel();
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error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);
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unlock_kernel();
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if (error < 0)
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goto error;
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SetPageUptodate(page);
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unlock_page(page);
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return 0;
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error:
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SetPageError(page);
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unlock_page(page);
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return -EIO;
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}
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static void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd)
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{
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struct inode *inode = dentry->d_inode;
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struct page *page;
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void *err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
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if (err)
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goto read_failed;
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page = read_cache_page(&inode->i_data, 0,
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(filler_t *)nfs_symlink_filler, inode);
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if (IS_ERR(page)) {
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err = page;
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goto read_failed;
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}
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if (!PageUptodate(page)) {
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err = ERR_PTR(-EIO);
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goto getlink_read_error;
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}
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nd_set_link(nd, kmap(page));
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return page;
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getlink_read_error:
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page_cache_release(page);
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read_failed:
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nd_set_link(nd, err);
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return NULL;
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}
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static void nfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
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{
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if (cookie) {
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struct page *page = cookie;
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kunmap(page);
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page_cache_release(page);
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}
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}
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/*
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* symlinks can't do much...
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*/
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struct inode_operations nfs_symlink_inode_operations = {
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.readlink = generic_readlink,
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.follow_link = nfs_follow_link,
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.put_link = nfs_put_link,
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.getattr = nfs_getattr,
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.setattr = nfs_setattr,
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};
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