Block: use round_jiffies_up()
[linux-2.6/mini2440.git] / fs / ecryptfs / file.c
blobeb3dc4c7ac066c45c99d26218ccda7f623cae9c6
1 /**
2 * eCryptfs: Linux filesystem encryption layer
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
8 * Michael C. Thompson <mcthomps@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
23 * 02111-1307, USA.
26 #include <linux/file.h>
27 #include <linux/poll.h>
28 #include <linux/mount.h>
29 #include <linux/pagemap.h>
30 #include <linux/security.h>
31 #include <linux/compat.h>
32 #include <linux/fs_stack.h>
33 #include <linux/smp_lock.h>
34 #include "ecryptfs_kernel.h"
36 /**
37 * ecryptfs_read_update_atime
39 * generic_file_read updates the atime of upper layer inode. But, it
40 * doesn't give us a chance to update the atime of the lower layer
41 * inode. This function is a wrapper to generic_file_read. It
42 * updates the atime of the lower level inode if generic_file_read
43 * returns without any errors. This is to be used only for file reads.
44 * The function to be used for directory reads is ecryptfs_read.
46 static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
47 const struct iovec *iov,
48 unsigned long nr_segs, loff_t pos)
50 int rc;
51 struct dentry *lower_dentry;
52 struct vfsmount *lower_vfsmount;
53 struct file *file = iocb->ki_filp;
55 rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
57 * Even though this is a async interface, we need to wait
58 * for IO to finish to update atime
60 if (-EIOCBQUEUED == rc)
61 rc = wait_on_sync_kiocb(iocb);
62 if (rc >= 0) {
63 lower_dentry = ecryptfs_dentry_to_lower(file->f_path.dentry);
64 lower_vfsmount = ecryptfs_dentry_to_lower_mnt(file->f_path.dentry);
65 touch_atime(lower_vfsmount, lower_dentry);
67 return rc;
70 struct ecryptfs_getdents_callback {
71 void *dirent;
72 struct dentry *dentry;
73 filldir_t filldir;
74 int filldir_called;
75 int entries_written;
78 /* Inspired by generic filldir in fs/readdir.c */
79 static int
80 ecryptfs_filldir(void *dirent, const char *name, int namelen, loff_t offset,
81 u64 ino, unsigned int d_type)
83 struct ecryptfs_crypt_stat *crypt_stat;
84 struct ecryptfs_getdents_callback *buf =
85 (struct ecryptfs_getdents_callback *)dirent;
86 int rc;
87 int decoded_length;
88 char *decoded_name;
90 crypt_stat = ecryptfs_dentry_to_private(buf->dentry)->crypt_stat;
91 buf->filldir_called++;
92 decoded_length = ecryptfs_decode_filename(crypt_stat, name, namelen,
93 &decoded_name);
94 if (decoded_length < 0) {
95 rc = decoded_length;
96 goto out;
98 rc = buf->filldir(buf->dirent, decoded_name, decoded_length, offset,
99 ino, d_type);
100 kfree(decoded_name);
101 if (rc >= 0)
102 buf->entries_written++;
103 out:
104 return rc;
108 * ecryptfs_readdir
109 * @file: The ecryptfs file struct
110 * @dirent: Directory entry
111 * @filldir: The filldir callback function
113 static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir)
115 int rc;
116 struct file *lower_file;
117 struct inode *inode;
118 struct ecryptfs_getdents_callback buf;
120 lower_file = ecryptfs_file_to_lower(file);
121 lower_file->f_pos = file->f_pos;
122 inode = file->f_path.dentry->d_inode;
123 memset(&buf, 0, sizeof(buf));
124 buf.dirent = dirent;
125 buf.dentry = file->f_path.dentry;
126 buf.filldir = filldir;
127 buf.filldir_called = 0;
128 buf.entries_written = 0;
129 rc = vfs_readdir(lower_file, ecryptfs_filldir, (void *)&buf);
130 file->f_pos = lower_file->f_pos;
131 if (rc < 0)
132 goto out;
133 if (buf.filldir_called && !buf.entries_written)
134 goto out;
135 if (rc >= 0)
136 fsstack_copy_attr_atime(inode,
137 lower_file->f_path.dentry->d_inode);
138 out:
139 return rc;
142 struct kmem_cache *ecryptfs_file_info_cache;
145 * ecryptfs_open
146 * @inode: inode speciying file to open
147 * @file: Structure to return filled in
149 * Opens the file specified by inode.
151 * Returns zero on success; non-zero otherwise
153 static int ecryptfs_open(struct inode *inode, struct file *file)
155 int rc = 0;
156 struct ecryptfs_crypt_stat *crypt_stat = NULL;
157 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
158 struct dentry *ecryptfs_dentry = file->f_path.dentry;
159 /* Private value of ecryptfs_dentry allocated in
160 * ecryptfs_lookup() */
161 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
162 struct ecryptfs_file_info *file_info;
164 mount_crypt_stat = &ecryptfs_superblock_to_private(
165 ecryptfs_dentry->d_sb)->mount_crypt_stat;
166 if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
167 && ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR)
168 || (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC)
169 || (file->f_flags & O_APPEND))) {
170 printk(KERN_WARNING "Mount has encrypted view enabled; "
171 "files may only be read\n");
172 rc = -EPERM;
173 goto out;
175 /* Released in ecryptfs_release or end of function if failure */
176 file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
177 ecryptfs_set_file_private(file, file_info);
178 if (!file_info) {
179 ecryptfs_printk(KERN_ERR,
180 "Error attempting to allocate memory\n");
181 rc = -ENOMEM;
182 goto out;
184 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
185 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
186 mutex_lock(&crypt_stat->cs_mutex);
187 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) {
188 ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
189 /* Policy code enabled in future release */
190 crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED
191 | ECRYPTFS_ENCRYPTED);
193 mutex_unlock(&crypt_stat->cs_mutex);
194 if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY)
195 && !(file->f_flags & O_RDONLY)) {
196 rc = -EPERM;
197 printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs "
198 "file must hence be opened RO\n", __func__);
199 goto out;
201 if (!ecryptfs_inode_to_private(inode)->lower_file) {
202 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
203 if (rc) {
204 printk(KERN_ERR "%s: Error attempting to initialize "
205 "the persistent file for the dentry with name "
206 "[%s]; rc = [%d]\n", __func__,
207 ecryptfs_dentry->d_name.name, rc);
208 goto out;
211 ecryptfs_set_file_lower(
212 file, ecryptfs_inode_to_private(inode)->lower_file);
213 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
214 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
215 mutex_lock(&crypt_stat->cs_mutex);
216 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
217 mutex_unlock(&crypt_stat->cs_mutex);
218 rc = 0;
219 goto out;
221 mutex_lock(&crypt_stat->cs_mutex);
222 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
223 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
224 rc = ecryptfs_read_metadata(ecryptfs_dentry);
225 if (rc) {
226 ecryptfs_printk(KERN_DEBUG,
227 "Valid headers not found\n");
228 if (!(mount_crypt_stat->flags
229 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
230 rc = -EIO;
231 printk(KERN_WARNING "Either the lower file "
232 "is not in a valid eCryptfs format, "
233 "or the key could not be retrieved. "
234 "Plaintext passthrough mode is not "
235 "enabled; returning -EIO\n");
236 mutex_unlock(&crypt_stat->cs_mutex);
237 goto out_free;
239 rc = 0;
240 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
241 mutex_unlock(&crypt_stat->cs_mutex);
242 goto out;
245 mutex_unlock(&crypt_stat->cs_mutex);
246 ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] "
247 "size: [0x%.16x]\n", inode, inode->i_ino,
248 i_size_read(inode));
249 goto out;
250 out_free:
251 kmem_cache_free(ecryptfs_file_info_cache,
252 ecryptfs_file_to_private(file));
253 out:
254 return rc;
257 static int ecryptfs_flush(struct file *file, fl_owner_t td)
259 int rc = 0;
260 struct file *lower_file = NULL;
262 lower_file = ecryptfs_file_to_lower(file);
263 if (lower_file->f_op && lower_file->f_op->flush)
264 rc = lower_file->f_op->flush(lower_file, td);
265 return rc;
268 static int ecryptfs_release(struct inode *inode, struct file *file)
270 kmem_cache_free(ecryptfs_file_info_cache,
271 ecryptfs_file_to_private(file));
272 return 0;
275 static int
276 ecryptfs_fsync(struct file *file, struct dentry *dentry, int datasync)
278 struct file *lower_file = ecryptfs_file_to_lower(file);
279 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
280 struct inode *lower_inode = lower_dentry->d_inode;
281 int rc = -EINVAL;
283 if (lower_inode->i_fop->fsync) {
284 mutex_lock(&lower_inode->i_mutex);
285 rc = lower_inode->i_fop->fsync(lower_file, lower_dentry,
286 datasync);
287 mutex_unlock(&lower_inode->i_mutex);
289 return rc;
292 static int ecryptfs_fasync(int fd, struct file *file, int flag)
294 int rc = 0;
295 struct file *lower_file = NULL;
297 lock_kernel();
298 lower_file = ecryptfs_file_to_lower(file);
299 if (lower_file->f_op && lower_file->f_op->fasync)
300 rc = lower_file->f_op->fasync(fd, lower_file, flag);
301 unlock_kernel();
302 return rc;
305 static int ecryptfs_ioctl(struct inode *inode, struct file *file,
306 unsigned int cmd, unsigned long arg);
308 const struct file_operations ecryptfs_dir_fops = {
309 .readdir = ecryptfs_readdir,
310 .ioctl = ecryptfs_ioctl,
311 .mmap = generic_file_mmap,
312 .open = ecryptfs_open,
313 .flush = ecryptfs_flush,
314 .release = ecryptfs_release,
315 .fsync = ecryptfs_fsync,
316 .fasync = ecryptfs_fasync,
317 .splice_read = generic_file_splice_read,
320 const struct file_operations ecryptfs_main_fops = {
321 .llseek = generic_file_llseek,
322 .read = do_sync_read,
323 .aio_read = ecryptfs_read_update_atime,
324 .write = do_sync_write,
325 .aio_write = generic_file_aio_write,
326 .readdir = ecryptfs_readdir,
327 .ioctl = ecryptfs_ioctl,
328 .mmap = generic_file_mmap,
329 .open = ecryptfs_open,
330 .flush = ecryptfs_flush,
331 .release = ecryptfs_release,
332 .fsync = ecryptfs_fsync,
333 .fasync = ecryptfs_fasync,
334 .splice_read = generic_file_splice_read,
337 static int
338 ecryptfs_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
339 unsigned long arg)
341 int rc = 0;
342 struct file *lower_file = NULL;
344 if (ecryptfs_file_to_private(file))
345 lower_file = ecryptfs_file_to_lower(file);
346 if (lower_file && lower_file->f_op && lower_file->f_op->ioctl)
347 rc = lower_file->f_op->ioctl(ecryptfs_inode_to_lower(inode),
348 lower_file, cmd, arg);
349 else
350 rc = -ENOTTY;
351 return rc;