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_dentry_delete - called when dentry refcount equals 0 47 * @dentry: dentry in question 48 * 49 * By returning 1 here we should remove cacheing of unused 50 * dentry components. 51 * 52 */ 53 54 static int v9fs_dentry_delete(const struct dentry *dentry) 55 { 56 p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n", 57 dentry->d_name.name, dentry); 58 59 return 1; 60 } 61 62 /** 63 * v9fs_cached_dentry_delete - called when dentry refcount equals 0 64 * @dentry: dentry in question 65 * 66 */ 67 static int v9fs_cached_dentry_delete(const struct dentry *dentry) 68 { 69 p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n", 70 dentry->d_name.name, dentry); 71 72 /* Don't cache negative dentries */ 73 if (!dentry->d_inode) 74 return 1; 75 return 0; 76 } 77 78 /** 79 * v9fs_dentry_release - called when dentry is going to be freed 80 * @dentry: dentry that is being release 81 * 82 */ 83 84 static void v9fs_dentry_release(struct dentry *dentry) 85 { 86 struct hlist_node *p, *n; 87 p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n", 88 dentry->d_name.name, dentry); 89 hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata) 90 p9_client_clunk(hlist_entry(p, struct p9_fid, dlist)); 91 dentry->d_fsdata = NULL; 92 } 93 94 static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags) 95 { 96 struct p9_fid *fid; 97 struct inode *inode; 98 struct v9fs_inode *v9inode; 99 100 if (flags & LOOKUP_RCU) 101 return -ECHILD; 102 103 inode = dentry->d_inode; 104 if (!inode) 105 goto out_valid; 106 107 v9inode = V9FS_I(inode); 108 if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) { 109 int retval; 110 struct v9fs_session_info *v9ses; 111 fid = v9fs_fid_lookup(dentry); 112 if (IS_ERR(fid)) 113 return PTR_ERR(fid); 114 115 v9ses = v9fs_inode2v9ses(inode); 116 if (v9fs_proto_dotl(v9ses)) 117 retval = v9fs_refresh_inode_dotl(fid, inode); 118 else 119 retval = v9fs_refresh_inode(fid, inode); 120 if (retval == -ENOENT) 121 return 0; 122 if (retval < 0) 123 return retval; 124 } 125 out_valid: 126 return 1; 127 } 128 129 const struct dentry_operations v9fs_cached_dentry_operations = { 130 .d_revalidate = v9fs_lookup_revalidate, 131 .d_weak_revalidate = v9fs_lookup_revalidate, 132 .d_delete = v9fs_cached_dentry_delete, 133 .d_release = v9fs_dentry_release, 134 }; 135 136 const struct dentry_operations v9fs_dentry_operations = { 137 .d_delete = v9fs_dentry_delete, 138 .d_release = v9fs_dentry_release, 139 }; 140