Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 1 | /* -*- mode: c; c-basic-offset: 8; -*- |
| 2 | * vim: noexpandtab sw=8 ts=8 sts=0: |
| 3 | * |
| 4 | * inode.c - basic inode and dentry operations. |
| 5 | * |
| 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. |
| 10 | * |
| 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. |
| 15 | * |
| 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. |
| 20 | * |
| 21 | * Based on sysfs: |
| 22 | * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel |
| 23 | * |
| 24 | * configfs Copyright (C) 2005 Oracle. All rights reserved. |
| 25 | * |
Paul Bolle | 395cf96 | 2011-08-15 02:02:26 +0200 | [diff] [blame] | 26 | * Please see Documentation/filesystems/configfs/configfs.txt for more |
| 27 | * information. |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 28 | */ |
| 29 | |
| 30 | #undef DEBUG |
| 31 | |
| 32 | #include <linux/pagemap.h> |
| 33 | #include <linux/namei.h> |
| 34 | #include <linux/backing-dev.h> |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 35 | #include <linux/capability.h> |
Alexey Dobriyan | e8edc6e | 2007-05-21 01:22:52 +0400 | [diff] [blame] | 36 | #include <linux/sched.h> |
Louis Rilling | e74cc06 | 2009-01-28 19:18:32 +0100 | [diff] [blame] | 37 | #include <linux/lockdep.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 38 | #include <linux/slab.h> |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 39 | |
| 40 | #include <linux/configfs.h> |
| 41 | #include "configfs_internal.h" |
| 42 | |
Louis Rilling | e74cc06 | 2009-01-28 19:18:32 +0100 | [diff] [blame] | 43 | #ifdef CONFIG_LOCKDEP |
| 44 | static struct lock_class_key default_group_class[MAX_LOCK_DEPTH]; |
| 45 | #endif |
| 46 | |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 47 | extern struct super_block * configfs_sb; |
| 48 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 49 | static const struct address_space_operations configfs_aops = { |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 50 | .readpage = simple_readpage, |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 51 | .write_begin = simple_write_begin, |
| 52 | .write_end = simple_write_end, |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 53 | }; |
| 54 | |
| 55 | static struct backing_dev_info configfs_backing_dev_info = { |
Jens Axboe | d993831 | 2009-06-12 14:45:52 +0200 | [diff] [blame] | 56 | .name = "configfs", |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 57 | .ra_pages = 0, /* No readahead */ |
Miklos Szeredi | e4ad08f | 2008-04-30 00:54:37 -0700 | [diff] [blame] | 58 | .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 59 | }; |
| 60 | |
Arjan van de Ven | 754661f | 2007-02-12 00:55:38 -0800 | [diff] [blame] | 61 | static const struct inode_operations configfs_inode_operations ={ |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 62 | .setattr = configfs_setattr, |
| 63 | }; |
| 64 | |
| 65 | int configfs_setattr(struct dentry * dentry, struct iattr * iattr) |
| 66 | { |
| 67 | struct inode * inode = dentry->d_inode; |
| 68 | struct configfs_dirent * sd = dentry->d_fsdata; |
| 69 | struct iattr * sd_iattr; |
| 70 | unsigned int ia_valid = iattr->ia_valid; |
| 71 | int error; |
| 72 | |
| 73 | if (!sd) |
| 74 | return -EINVAL; |
| 75 | |
| 76 | sd_iattr = sd->s_iattr; |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 77 | if (!sd_iattr) { |
| 78 | /* setting attributes for the first time, allocate now */ |
Panagiotis Issaris | f8314dc | 2006-09-27 01:49:37 -0700 | [diff] [blame] | 79 | sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 80 | if (!sd_iattr) |
| 81 | return -ENOMEM; |
| 82 | /* assign default attributes */ |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 83 | sd_iattr->ia_mode = sd->s_mode; |
| 84 | sd_iattr->ia_uid = 0; |
| 85 | sd_iattr->ia_gid = 0; |
| 86 | sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME; |
| 87 | sd->s_iattr = sd_iattr; |
| 88 | } |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 89 | /* attributes were changed atleast once in past */ |
| 90 | |
Nick Piggin | 75de46b | 2010-05-31 17:58:02 +1000 | [diff] [blame] | 91 | error = simple_setattr(dentry, iattr); |
| 92 | if (error) |
| 93 | return error; |
| 94 | |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 95 | if (ia_valid & ATTR_UID) |
| 96 | sd_iattr->ia_uid = iattr->ia_uid; |
| 97 | if (ia_valid & ATTR_GID) |
| 98 | sd_iattr->ia_gid = iattr->ia_gid; |
| 99 | if (ia_valid & ATTR_ATIME) |
| 100 | sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime, |
| 101 | inode->i_sb->s_time_gran); |
| 102 | if (ia_valid & ATTR_MTIME) |
| 103 | sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime, |
| 104 | inode->i_sb->s_time_gran); |
| 105 | if (ia_valid & ATTR_CTIME) |
| 106 | sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime, |
| 107 | inode->i_sb->s_time_gran); |
| 108 | if (ia_valid & ATTR_MODE) { |
| 109 | umode_t mode = iattr->ia_mode; |
| 110 | |
| 111 | if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) |
| 112 | mode &= ~S_ISGID; |
| 113 | sd_iattr->ia_mode = sd->s_mode = mode; |
| 114 | } |
| 115 | |
| 116 | return error; |
| 117 | } |
| 118 | |
| 119 | static inline void set_default_inode_attr(struct inode * inode, mode_t mode) |
| 120 | { |
| 121 | inode->i_mode = mode; |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 122 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 123 | } |
| 124 | |
| 125 | static inline void set_inode_attr(struct inode * inode, struct iattr * iattr) |
| 126 | { |
| 127 | inode->i_mode = iattr->ia_mode; |
| 128 | inode->i_uid = iattr->ia_uid; |
| 129 | inode->i_gid = iattr->ia_gid; |
| 130 | inode->i_atime = iattr->ia_atime; |
| 131 | inode->i_mtime = iattr->ia_mtime; |
| 132 | inode->i_ctime = iattr->ia_ctime; |
| 133 | } |
| 134 | |
| 135 | struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd) |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 136 | { |
| 137 | struct inode * inode = new_inode(configfs_sb); |
| 138 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 139 | inode->i_ino = get_next_ino(); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 140 | inode->i_mapping->a_ops = &configfs_aops; |
| 141 | inode->i_mapping->backing_dev_info = &configfs_backing_dev_info; |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 142 | inode->i_op = &configfs_inode_operations; |
| 143 | |
| 144 | if (sd->s_iattr) { |
| 145 | /* sysfs_dirent has non-default attributes |
| 146 | * get them for the new inode from persistent copy |
| 147 | * in sysfs_dirent |
| 148 | */ |
| 149 | set_inode_attr(inode, sd->s_iattr); |
| 150 | } else |
| 151 | set_default_inode_attr(inode, mode); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 152 | } |
| 153 | return inode; |
| 154 | } |
| 155 | |
Louis Rilling | e74cc06 | 2009-01-28 19:18:32 +0100 | [diff] [blame] | 156 | #ifdef CONFIG_LOCKDEP |
| 157 | |
| 158 | static void configfs_set_inode_lock_class(struct configfs_dirent *sd, |
| 159 | struct inode *inode) |
| 160 | { |
| 161 | int depth = sd->s_depth; |
| 162 | |
| 163 | if (depth > 0) { |
| 164 | if (depth <= ARRAY_SIZE(default_group_class)) { |
| 165 | lockdep_set_class(&inode->i_mutex, |
| 166 | &default_group_class[depth - 1]); |
| 167 | } else { |
| 168 | /* |
| 169 | * In practice the maximum level of locking depth is |
| 170 | * already reached. Just inform about possible reasons. |
| 171 | */ |
| 172 | printk(KERN_INFO "configfs: Too many levels of inodes" |
| 173 | " for the locking correctness validator.\n"); |
| 174 | printk(KERN_INFO "Spurious warnings may appear.\n"); |
| 175 | } |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | #else /* CONFIG_LOCKDEP */ |
| 180 | |
| 181 | static void configfs_set_inode_lock_class(struct configfs_dirent *sd, |
| 182 | struct inode *inode) |
| 183 | { |
| 184 | } |
| 185 | |
| 186 | #endif /* CONFIG_LOCKDEP */ |
| 187 | |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 188 | int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *)) |
| 189 | { |
| 190 | int error = 0; |
| 191 | struct inode * inode = NULL; |
| 192 | if (dentry) { |
| 193 | if (!dentry->d_inode) { |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 194 | struct configfs_dirent *sd = dentry->d_fsdata; |
| 195 | if ((inode = configfs_new_inode(mode, sd))) { |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 196 | if (dentry->d_parent && dentry->d_parent->d_inode) { |
| 197 | struct inode *p_inode = dentry->d_parent->d_inode; |
| 198 | p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; |
| 199 | } |
Louis Rilling | e74cc06 | 2009-01-28 19:18:32 +0100 | [diff] [blame] | 200 | configfs_set_inode_lock_class(sd, inode); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 201 | goto Proceed; |
| 202 | } |
| 203 | else |
| 204 | error = -ENOMEM; |
| 205 | } else |
| 206 | error = -EEXIST; |
| 207 | } else |
| 208 | error = -ENOENT; |
| 209 | goto Done; |
| 210 | |
| 211 | Proceed: |
| 212 | if (init) |
| 213 | error = init(inode); |
| 214 | if (!error) { |
| 215 | d_instantiate(dentry, inode); |
| 216 | if (S_ISDIR(mode) || S_ISLNK(mode)) |
| 217 | dget(dentry); /* pin link and directory dentries in core */ |
| 218 | } else |
| 219 | iput(inode); |
| 220 | Done: |
| 221 | return error; |
| 222 | } |
| 223 | |
| 224 | /* |
| 225 | * Get the name for corresponding element represented by the given configfs_dirent |
| 226 | */ |
| 227 | const unsigned char * configfs_get_name(struct configfs_dirent *sd) |
| 228 | { |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 229 | struct configfs_attribute *attr; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 230 | |
Eric Sesterhenn / snakebyte | 1a1974f | 2006-01-27 10:32:24 +0100 | [diff] [blame] | 231 | BUG_ON(!sd || !sd->s_element); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 232 | |
| 233 | /* These always have a dentry, so use that */ |
| 234 | if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK)) |
| 235 | return sd->s_dentry->d_name.name; |
| 236 | |
| 237 | if (sd->s_type & CONFIGFS_ITEM_ATTR) { |
| 238 | attr = sd->s_element; |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 239 | return attr->ca_name; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 240 | } |
| 241 | return NULL; |
| 242 | } |
| 243 | |
| 244 | |
| 245 | /* |
| 246 | * Unhashes the dentry corresponding to given configfs_dirent |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 247 | * Called with parent inode's i_mutex held. |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 248 | */ |
| 249 | void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) |
| 250 | { |
| 251 | struct dentry * dentry = sd->s_dentry; |
| 252 | |
| 253 | if (dentry) { |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 254 | spin_lock(&dentry->d_lock); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 255 | if (!(d_unhashed(dentry) && dentry->d_inode)) { |
Nick Piggin | dc0474b | 2011-01-07 17:49:43 +1100 | [diff] [blame] | 256 | dget_dlock(dentry); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 257 | __d_drop(dentry); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 258 | spin_unlock(&dentry->d_lock); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 259 | simple_unlink(parent->d_inode, dentry); |
Nick Piggin | b5c84bf | 2011-01-07 17:49:38 +1100 | [diff] [blame] | 260 | } else |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 261 | spin_unlock(&dentry->d_lock); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 262 | } |
| 263 | } |
| 264 | |
| 265 | void configfs_hash_and_remove(struct dentry * dir, const char * name) |
| 266 | { |
| 267 | struct configfs_dirent * sd; |
| 268 | struct configfs_dirent * parent_sd = dir->d_fsdata; |
| 269 | |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 270 | if (dir->d_inode == NULL) |
| 271 | /* no inode means this hasn't been made visible yet */ |
| 272 | return; |
| 273 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 274 | mutex_lock(&dir->d_inode->i_mutex); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 275 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { |
| 276 | if (!sd->s_element) |
| 277 | continue; |
| 278 | if (!strcmp(configfs_get_name(sd), name)) { |
Louis Rilling | 6f61076 | 2008-06-16 19:00:58 +0200 | [diff] [blame] | 279 | spin_lock(&configfs_dirent_lock); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 280 | list_del_init(&sd->s_sibling); |
Louis Rilling | 6f61076 | 2008-06-16 19:00:58 +0200 | [diff] [blame] | 281 | spin_unlock(&configfs_dirent_lock); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 282 | configfs_drop_dentry(sd, dir); |
| 283 | configfs_put(sd); |
| 284 | break; |
| 285 | } |
| 286 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 287 | mutex_unlock(&dir->d_inode->i_mutex); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 288 | } |
| 289 | |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 290 | int __init configfs_inode_init(void) |
| 291 | { |
| 292 | return bdi_init(&configfs_backing_dev_info); |
| 293 | } |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 294 | |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 295 | void __exit configfs_inode_exit(void) |
| 296 | { |
| 297 | bdi_destroy(&configfs_backing_dev_info); |
| 298 | } |