1 /* 2 * linux/fs/9p/vfs_dentry.c 3 * 4 * This file contians vfs dentry ops for the 9P2000 protocol. 5 * 6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> 7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 11 * as published by the Free Software Foundation. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to: 20 * Free Software Foundation 21 * 51 Franklin Street, Fifth Floor 22 * Boston, MA 02111-1301 USA 23 * 24 */ 25 26 #include <linux/module.h> 27 #include <linux/errno.h> 28 #include <linux/fs.h> 29 #include <linux/file.h> 30 #include <linux/pagemap.h> 31 #include <linux/stat.h> 32 #include <linux/string.h> 33 #include <linux/inet.h> 34 #include <linux/namei.h> 35 #include <linux/idr.h> 36 #include <linux/sched.h> 37 #include <linux/slab.h> 38 #include <net/9p/9p.h> 39 #include <net/9p/client.h> 40 41 #include "v9fs.h" 42 #include "v9fs_vfs.h" 43 #include "fid.h" 44 45 /** 46 * v9fs_cached_dentry_delete - called when dentry refcount equals 0 47 * @dentry: dentry in question 48 * 49 */ 50 static int v9fs_cached_dentry_delete(const struct dentry *dentry) 51 { 52 p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n", 53 dentry->d_name.name, dentry); 54 55 /* Don't cache negative dentries */ 56 if (!dentry->d_inode) 57 return 1; 58 return 0; 59 } 60 61 /** 62 * v9fs_dentry_release - called when dentry is going to be freed 63 * @dentry: dentry that is being release 64 * 65 */ 66 67 static void v9fs_dentry_release(struct dentry *dentry) 68 { 69 struct hlist_node *p, *n; 70 p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n", 71 dentry->d_name.name, dentry); 72 hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata) 73 p9_client_clunk(hlist_entry(p, struct p9_fid, dlist)); 74 dentry->d_fsdata = NULL; 75 } 76 77 static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags) 78 { 79 struct p9_fid *fid; 80 struct inode *inode; 81 struct v9fs_inode *v9inode; 82 83 if (flags & LOOKUP_RCU) 84 return -ECHILD; 85 86 inode = dentry->d_inode; 87 if (!inode) 88 goto out_valid; 89 90 v9inode = V9FS_I(inode); 91 if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) { 92 int retval; 93 struct v9fs_session_info *v9ses; 94 fid = v9fs_fid_lookup(dentry); 95 if (IS_ERR(fid)) 96 return PTR_ERR(fid); 97 98 v9ses = v9fs_inode2v9ses(inode); 99 if (v9fs_proto_dotl(v9ses)) 100 retval = v9fs_refresh_inode_dotl(fid, inode); 101 else 102 retval = v9fs_refresh_inode(fid, inode); 103 if (retval == -ENOENT) 104 return 0; 105 if (retval < 0) 106 return retval; 107 } 108 out_valid: 109 return 1; 110 } 111 112 const struct dentry_operations v9fs_cached_dentry_operations = { 113 .d_revalidate = v9fs_lookup_revalidate, 114 .d_weak_revalidate = v9fs_lookup_revalidate, 115 .d_delete = v9fs_cached_dentry_delete, 116 .d_release = v9fs_dentry_release, 117 }; 118 119 const struct dentry_operations v9fs_dentry_operations = { 120 .d_delete = always_delete_dentry, 121 .d_release = v9fs_dentry_release, 122 }; 123