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 | * |
| 26 | * Please see Documentation/filesystems/configfs.txt for more information. |
| 27 | */ |
| 28 | |
| 29 | #undef DEBUG |
| 30 | |
| 31 | #include <linux/pagemap.h> |
| 32 | #include <linux/namei.h> |
| 33 | #include <linux/backing-dev.h> |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 34 | #include <linux/capability.h> |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 35 | |
| 36 | #include <linux/configfs.h> |
| 37 | #include "configfs_internal.h" |
| 38 | |
| 39 | extern struct super_block * configfs_sb; |
| 40 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 41 | static const struct address_space_operations configfs_aops = { |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 42 | .readpage = simple_readpage, |
| 43 | .prepare_write = simple_prepare_write, |
| 44 | .commit_write = simple_commit_write |
| 45 | }; |
| 46 | |
| 47 | static struct backing_dev_info configfs_backing_dev_info = { |
| 48 | .ra_pages = 0, /* No readahead */ |
| 49 | .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, |
| 50 | }; |
| 51 | |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 52 | static struct inode_operations configfs_inode_operations ={ |
| 53 | .setattr = configfs_setattr, |
| 54 | }; |
| 55 | |
| 56 | int configfs_setattr(struct dentry * dentry, struct iattr * iattr) |
| 57 | { |
| 58 | struct inode * inode = dentry->d_inode; |
| 59 | struct configfs_dirent * sd = dentry->d_fsdata; |
| 60 | struct iattr * sd_iattr; |
| 61 | unsigned int ia_valid = iattr->ia_valid; |
| 62 | int error; |
| 63 | |
| 64 | if (!sd) |
| 65 | return -EINVAL; |
| 66 | |
| 67 | sd_iattr = sd->s_iattr; |
| 68 | |
| 69 | error = inode_change_ok(inode, iattr); |
| 70 | if (error) |
| 71 | return error; |
| 72 | |
| 73 | error = inode_setattr(inode, iattr); |
| 74 | if (error) |
| 75 | return error; |
| 76 | |
| 77 | if (!sd_iattr) { |
| 78 | /* setting attributes for the first time, allocate now */ |
| 79 | sd_iattr = kmalloc(sizeof(struct iattr), GFP_KERNEL); |
| 80 | if (!sd_iattr) |
| 81 | return -ENOMEM; |
| 82 | /* assign default attributes */ |
| 83 | memset(sd_iattr, 0, sizeof(struct iattr)); |
| 84 | sd_iattr->ia_mode = sd->s_mode; |
| 85 | sd_iattr->ia_uid = 0; |
| 86 | sd_iattr->ia_gid = 0; |
| 87 | sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME; |
| 88 | sd->s_iattr = sd_iattr; |
| 89 | } |
| 90 | |
| 91 | /* attributes were changed atleast once in past */ |
| 92 | |
| 93 | if (ia_valid & ATTR_UID) |
| 94 | sd_iattr->ia_uid = iattr->ia_uid; |
| 95 | if (ia_valid & ATTR_GID) |
| 96 | sd_iattr->ia_gid = iattr->ia_gid; |
| 97 | if (ia_valid & ATTR_ATIME) |
| 98 | sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime, |
| 99 | inode->i_sb->s_time_gran); |
| 100 | if (ia_valid & ATTR_MTIME) |
| 101 | sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime, |
| 102 | inode->i_sb->s_time_gran); |
| 103 | if (ia_valid & ATTR_CTIME) |
| 104 | sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime, |
| 105 | inode->i_sb->s_time_gran); |
| 106 | if (ia_valid & ATTR_MODE) { |
| 107 | umode_t mode = iattr->ia_mode; |
| 108 | |
| 109 | if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) |
| 110 | mode &= ~S_ISGID; |
| 111 | sd_iattr->ia_mode = sd->s_mode = mode; |
| 112 | } |
| 113 | |
| 114 | return error; |
| 115 | } |
| 116 | |
| 117 | static inline void set_default_inode_attr(struct inode * inode, mode_t mode) |
| 118 | { |
| 119 | inode->i_mode = mode; |
| 120 | inode->i_uid = 0; |
| 121 | inode->i_gid = 0; |
| 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) { |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 139 | inode->i_blksize = PAGE_CACHE_SIZE; |
| 140 | inode->i_blocks = 0; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 141 | inode->i_mapping->a_ops = &configfs_aops; |
| 142 | inode->i_mapping->backing_dev_info = &configfs_backing_dev_info; |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 143 | inode->i_op = &configfs_inode_operations; |
| 144 | |
| 145 | if (sd->s_iattr) { |
| 146 | /* sysfs_dirent has non-default attributes |
| 147 | * get them for the new inode from persistent copy |
| 148 | * in sysfs_dirent |
| 149 | */ |
| 150 | set_inode_attr(inode, sd->s_iattr); |
| 151 | } else |
| 152 | set_default_inode_attr(inode, mode); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 153 | } |
| 154 | return inode; |
| 155 | } |
| 156 | |
| 157 | int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *)) |
| 158 | { |
| 159 | int error = 0; |
| 160 | struct inode * inode = NULL; |
| 161 | if (dentry) { |
| 162 | if (!dentry->d_inode) { |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 163 | struct configfs_dirent *sd = dentry->d_fsdata; |
| 164 | if ((inode = configfs_new_inode(mode, sd))) { |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 165 | if (dentry->d_parent && dentry->d_parent->d_inode) { |
| 166 | struct inode *p_inode = dentry->d_parent->d_inode; |
| 167 | p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; |
| 168 | } |
| 169 | goto Proceed; |
| 170 | } |
| 171 | else |
| 172 | error = -ENOMEM; |
| 173 | } else |
| 174 | error = -EEXIST; |
| 175 | } else |
| 176 | error = -ENOENT; |
| 177 | goto Done; |
| 178 | |
| 179 | Proceed: |
| 180 | if (init) |
| 181 | error = init(inode); |
| 182 | if (!error) { |
| 183 | d_instantiate(dentry, inode); |
| 184 | if (S_ISDIR(mode) || S_ISLNK(mode)) |
| 185 | dget(dentry); /* pin link and directory dentries in core */ |
| 186 | } else |
| 187 | iput(inode); |
| 188 | Done: |
| 189 | return error; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Get the name for corresponding element represented by the given configfs_dirent |
| 194 | */ |
| 195 | const unsigned char * configfs_get_name(struct configfs_dirent *sd) |
| 196 | { |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 197 | struct configfs_attribute *attr; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 198 | |
Eric Sesterhenn / snakebyte | 1a1974f | 2006-01-27 10:32:24 +0100 | [diff] [blame] | 199 | BUG_ON(!sd || !sd->s_element); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 200 | |
| 201 | /* These always have a dentry, so use that */ |
| 202 | if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK)) |
| 203 | return sd->s_dentry->d_name.name; |
| 204 | |
| 205 | if (sd->s_type & CONFIGFS_ITEM_ATTR) { |
| 206 | attr = sd->s_element; |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 207 | return attr->ca_name; |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 208 | } |
| 209 | return NULL; |
| 210 | } |
| 211 | |
| 212 | |
| 213 | /* |
| 214 | * Unhashes the dentry corresponding to given configfs_dirent |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 215 | * Called with parent inode's i_mutex held. |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 216 | */ |
| 217 | void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) |
| 218 | { |
| 219 | struct dentry * dentry = sd->s_dentry; |
| 220 | |
| 221 | if (dentry) { |
| 222 | spin_lock(&dcache_lock); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 223 | spin_lock(&dentry->d_lock); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 224 | if (!(d_unhashed(dentry) && dentry->d_inode)) { |
| 225 | dget_locked(dentry); |
| 226 | __d_drop(dentry); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 227 | spin_unlock(&dentry->d_lock); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 228 | spin_unlock(&dcache_lock); |
| 229 | simple_unlink(parent->d_inode, dentry); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 230 | } else { |
| 231 | spin_unlock(&dentry->d_lock); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 232 | spin_unlock(&dcache_lock); |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 233 | } |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 234 | } |
| 235 | } |
| 236 | |
| 237 | void configfs_hash_and_remove(struct dentry * dir, const char * name) |
| 238 | { |
| 239 | struct configfs_dirent * sd; |
| 240 | struct configfs_dirent * parent_sd = dir->d_fsdata; |
| 241 | |
Joel Becker | 3d0f89b | 2006-01-25 13:31:07 -0800 | [diff] [blame] | 242 | if (dir->d_inode == NULL) |
| 243 | /* no inode means this hasn't been made visible yet */ |
| 244 | return; |
| 245 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 246 | mutex_lock(&dir->d_inode->i_mutex); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 247 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { |
| 248 | if (!sd->s_element) |
| 249 | continue; |
| 250 | if (!strcmp(configfs_get_name(sd), name)) { |
| 251 | list_del_init(&sd->s_sibling); |
| 252 | configfs_drop_dentry(sd, dir); |
| 253 | configfs_put(sd); |
| 254 | break; |
| 255 | } |
| 256 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 257 | mutex_unlock(&dir->d_inode->i_mutex); |
Joel Becker | 7063fbf | 2005-12-15 14:29:43 -0800 | [diff] [blame] | 258 | } |
| 259 | |
| 260 | |