fs/9p/vfs_dentry.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * This file contians vfs dentry ops for the 9P2000 protocol.
   4  *
   5  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   6  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/errno.h>
  11 #include <linux/fs.h>
  12 #include <linux/file.h>
  13 #include <linux/pagemap.h>
  14 #include <linux/stat.h>
  15 #include <linux/string.h>
  16 #include <linux/inet.h>
  17 #include <linux/namei.h>
  18 #include <linux/sched.h>
  19 #include <linux/slab.h>
  20 #include <net/9p/9p.h>
  21 #include <net/9p/client.h>
  22
  23 #include "v9fs.h"
  24 #include "v9fs_vfs.h"
  25 #include "fid.h"
  26
  27 /**
  28  * v9fs_cached_dentry_delete - called when dentry refcount equals 0
  29  * @dentry:  dentry in question
  30  *
  31  */
  32 static int v9fs_cached_dentry_delete(const struct dentry *dentry)
  33 {
  34         p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
  35                  dentry, dentry);
  36
  37         /* Don't cache negative dentries */
  38         if (d_really_is_negative(dentry))
  39                 return 1;
  40         return 0;
  41 }
  42
  43 /**
  44  * v9fs_dentry_release - called when dentry is going to be freed
  45  * @dentry:  dentry that is being release
  46  *
  47  */
  48
  49 static void v9fs_dentry_release(struct dentry *dentry)
  50 {
  51         struct hlist_node *p, *n;
  52
  53         p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
  54                  dentry, dentry);
  55         hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata)
  56                 p9_fid_put(hlist_entry(p, struct p9_fid, dlist));
  57         dentry->d_fsdata = NULL;
  58 }
  59
  60 static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
  61 {
  62         struct p9_fid *fid;
  63         struct inode *inode;
  64         struct v9fs_inode *v9inode;
  65
  66         if (flags & LOOKUP_RCU)
  67                 return -ECHILD;
  68
  69         inode = d_inode(dentry);
  70         if (!inode)
  71                 goto out_valid;
  72
  73         v9inode = V9FS_I(inode);
  74         if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
  75                 int retval;
  76                 struct v9fs_session_info *v9ses;
  77
  78                 fid = v9fs_fid_lookup(dentry);
  79                 if (IS_ERR(fid))
  80                         return PTR_ERR(fid);
  81
  82                 v9ses = v9fs_inode2v9ses(inode);
  83                 if (v9fs_proto_dotl(v9ses))
  84                         retval = v9fs_refresh_inode_dotl(fid, inode);
  85                 else
  86                         retval = v9fs_refresh_inode(fid, inode);
  87                 p9_fid_put(fid);
  88
  89                 if (retval == -ENOENT)
  90                         return 0;
  91                 if (retval < 0)
  92                         return retval;
  93         }
  94 out_valid:
  95         return 1;
  96 }
  97
  98 const struct dentry_operations v9fs_cached_dentry_operations = {
  99         .d_revalidate = v9fs_lookup_revalidate,
 100         .d_weak_revalidate = v9fs_lookup_revalidate,
 101         .d_delete = v9fs_cached_dentry_delete,
 102         .d_release = v9fs_dentry_release,
 103 };
 104
 105 const struct dentry_operations v9fs_dentry_operations = {
 106         .d_delete = always_delete_dentry,
 107         .d_release = v9fs_dentry_release,
 108 };