LXR linux/fs/9p/vfs

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/fs/9p/vfs_dentry.c
   4 *
   5 * This file contians vfs dentry ops for the 9P2000 protocol.
   6 *
   7 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   8 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   9 */
  10
  11#include <linux/module.h>
  12#include <linux/errno.h>
  13#include <linux/fs.h>
  14#include <linux/file.h>
  15#include <linux/pagemap.h>
  16#include <linux/stat.h>
  17#include <linux/string.h>
  18#include <linux/inet.h>
  19#include <linux/namei.h>
  20#include <linux/idr.h>
  21#include <linux/sched.h>
  22#include <linux/slab.h>
  23#include <net/9p/9p.h>
  24#include <net/9p/client.h>
  25
  26#include "v9fs.h"
  27#include "v9fs_vfs.h"
  28#include "fid.h"
  29
  30/**
  31 * v9fs_cached_dentry_delete - called when dentry refcount equals 0
  32 * @dentry:  dentry in question
  33 *
  34 */
  35static int v9fs_cached_dentry_delete(const struct dentry *dentry)
  36{
  37        p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
  38                 dentry, dentry);
  39
  40        /* Don't cache negative dentries */
  41        if (d_really_is_negative(dentry))
  42                return 1;
  43        return 0;
  44}
  45
  46/**
  47 * v9fs_dentry_release - called when dentry is going to be freed
  48 * @dentry:  dentry that is being release
  49 *
  50 */
  51
  52static void v9fs_dentry_release(struct dentry *dentry)
  53{
  54        struct hlist_node *p, *n;
  55        p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
  56                 dentry, dentry);
  57        hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata)
  58                p9_client_clunk(hlist_entry(p, struct p9_fid, dlist));
  59        dentry->d_fsdata = NULL;
  60}
  61
  62static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
  63{
  64        struct p9_fid *fid;
  65        struct inode *inode;
  66        struct v9fs_inode *v9inode;
  67
  68        if (flags & LOOKUP_RCU)
  69                return -ECHILD;
  70
  71        inode = d_inode(dentry);
  72        if (!inode)
  73                goto out_valid;
  74
  75        v9inode = V9FS_I(inode);
  76        if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
  77                int retval;
  78                struct v9fs_session_info *v9ses;
  79                fid = v9fs_fid_lookup(dentry);
  80                if (IS_ERR(fid))
  81                        return PTR_ERR(fid);
  82
  83                v9ses = v9fs_inode2v9ses(inode);
  84                if (v9fs_proto_dotl(v9ses))
  85                        retval = v9fs_refresh_inode_dotl(fid, inode);
  86                else
  87                        retval = v9fs_refresh_inode(fid, inode);
  88                p9_client_clunk(fid);
  89
  90                if (retval == -ENOENT)
  91                        return 0;
  92                if (retval < 0)
  93                        return retval;
  94        }
  95out_valid:
  96        return 1;
  97}
  98
  99const struct dentry_operations v9fs_cached_dentry_operations = {
 100        .d_revalidate = v9fs_lookup_revalidate,
 101        .d_weak_revalidate = v9fs_lookup_revalidate,
 102        .d_delete = v9fs_cached_dentry_delete,
 103        .d_release = v9fs_dentry_release,
 104};
 105
 106const struct dentry_operations v9fs_dentry_operations = {
 107        .d_delete = always_delete_dentry,
 108        .d_release = v9fs_dentry_release,
 109};
 110