1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
4 * inode.c - basic inode and dentry operations.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
22 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
24 * configfs Copyright (C) 2005 Oracle. All rights reserved.
26 * Please see Documentation/filesystems/configfs.txt for more information.
31 #include <linux/pagemap.h>
32 #include <linux/namei.h>
33 #include <linux/backing-dev.h>
34 #include <linux/capability.h>
35 #include <linux/sched.h>
36 #include <linux/lockdep.h>
37 #include <linux/slab.h>
39 #include <linux/configfs.h>
40 #include "configfs_internal.h"
43 static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
46 extern struct super_block * configfs_sb;
48 static const struct address_space_operations configfs_aops = {
49 .readpage = simple_readpage,
50 .write_begin = simple_write_begin,
51 .write_end = simple_write_end,
54 static struct backing_dev_info configfs_backing_dev_info = {
56 .ra_pages = 0, /* No readahead */
57 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
60 static const struct inode_operations configfs_inode_operations ={
61 .setattr = configfs_setattr,
64 int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
66 struct inode * inode = dentry->d_inode;
67 struct configfs_dirent * sd = dentry->d_fsdata;
68 struct iattr * sd_iattr;
69 unsigned int ia_valid = iattr->ia_valid;
75 sd_iattr = sd->s_iattr;
77 error = inode_change_ok(inode, iattr);
81 error = inode_setattr(inode, iattr);
86 /* setting attributes for the first time, allocate now */
87 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
90 /* assign default attributes */
91 sd_iattr->ia_mode = sd->s_mode;
94 sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
95 sd->s_iattr = sd_iattr;
98 /* attributes were changed atleast once in past */
100 if (ia_valid & ATTR_UID)
101 sd_iattr->ia_uid = iattr->ia_uid;
102 if (ia_valid & ATTR_GID)
103 sd_iattr->ia_gid = iattr->ia_gid;
104 if (ia_valid & ATTR_ATIME)
105 sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
106 inode->i_sb->s_time_gran);
107 if (ia_valid & ATTR_MTIME)
108 sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
109 inode->i_sb->s_time_gran);
110 if (ia_valid & ATTR_CTIME)
111 sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
112 inode->i_sb->s_time_gran);
113 if (ia_valid & ATTR_MODE) {
114 umode_t mode = iattr->ia_mode;
116 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
118 sd_iattr->ia_mode = sd->s_mode = mode;
124 static inline void set_default_inode_attr(struct inode * inode, mode_t mode)
126 inode->i_mode = mode;
127 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
130 static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
132 inode->i_mode = iattr->ia_mode;
133 inode->i_uid = iattr->ia_uid;
134 inode->i_gid = iattr->ia_gid;
135 inode->i_atime = iattr->ia_atime;
136 inode->i_mtime = iattr->ia_mtime;
137 inode->i_ctime = iattr->ia_ctime;
140 struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd)
142 struct inode * inode = new_inode(configfs_sb);
144 inode->i_mapping->a_ops = &configfs_aops;
145 inode->i_mapping->backing_dev_info = &configfs_backing_dev_info;
146 inode->i_op = &configfs_inode_operations;
149 /* sysfs_dirent has non-default attributes
150 * get them for the new inode from persistent copy
153 set_inode_attr(inode, sd->s_iattr);
155 set_default_inode_attr(inode, mode);
160 #ifdef CONFIG_LOCKDEP
162 static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
165 int depth = sd->s_depth;
168 if (depth <= ARRAY_SIZE(default_group_class)) {
169 lockdep_set_class(&inode->i_mutex,
170 &default_group_class[depth - 1]);
173 * In practice the maximum level of locking depth is
174 * already reached. Just inform about possible reasons.
176 printk(KERN_INFO "configfs: Too many levels of inodes"
177 " for the locking correctness validator.\n");
178 printk(KERN_INFO "Spurious warnings may appear.\n");
183 #else /* CONFIG_LOCKDEP */
185 static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
190 #endif /* CONFIG_LOCKDEP */
192 int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
195 struct inode * inode = NULL;
197 if (!dentry->d_inode) {
198 struct configfs_dirent *sd = dentry->d_fsdata;
199 if ((inode = configfs_new_inode(mode, sd))) {
200 if (dentry->d_parent && dentry->d_parent->d_inode) {
201 struct inode *p_inode = dentry->d_parent->d_inode;
202 p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
204 configfs_set_inode_lock_class(sd, inode);
219 d_instantiate(dentry, inode);
220 if (S_ISDIR(mode) || S_ISLNK(mode))
221 dget(dentry); /* pin link and directory dentries in core */
229 * Get the name for corresponding element represented by the given configfs_dirent
231 const unsigned char * configfs_get_name(struct configfs_dirent *sd)
233 struct configfs_attribute *attr;
235 BUG_ON(!sd || !sd->s_element);
237 /* These always have a dentry, so use that */
238 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
239 return sd->s_dentry->d_name.name;
241 if (sd->s_type & CONFIGFS_ITEM_ATTR) {
242 attr = sd->s_element;
243 return attr->ca_name;
250 * Unhashes the dentry corresponding to given configfs_dirent
251 * Called with parent inode's i_mutex held.
253 void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
255 struct dentry * dentry = sd->s_dentry;
258 spin_lock(&dcache_lock);
259 spin_lock(&dentry->d_lock);
260 if (!(d_unhashed(dentry) && dentry->d_inode)) {
263 spin_unlock(&dentry->d_lock);
264 spin_unlock(&dcache_lock);
265 simple_unlink(parent->d_inode, dentry);
267 spin_unlock(&dentry->d_lock);
268 spin_unlock(&dcache_lock);
273 void configfs_hash_and_remove(struct dentry * dir, const char * name)
275 struct configfs_dirent * sd;
276 struct configfs_dirent * parent_sd = dir->d_fsdata;
278 if (dir->d_inode == NULL)
279 /* no inode means this hasn't been made visible yet */
282 mutex_lock(&dir->d_inode->i_mutex);
283 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
286 if (!strcmp(configfs_get_name(sd), name)) {
287 spin_lock(&configfs_dirent_lock);
288 list_del_init(&sd->s_sibling);
289 spin_unlock(&configfs_dirent_lock);
290 configfs_drop_dentry(sd, dir);
295 mutex_unlock(&dir->d_inode->i_mutex);
298 int __init configfs_inode_init(void)
300 return bdi_init(&configfs_backing_dev_info);
303 void __exit configfs_inode_exit(void)
305 bdi_destroy(&configfs_backing_dev_info);