[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / ecryptfs / file.c

/**
 * eCryptfs: Linux filesystem encryption layer
 *
 * Copyright (C) 1997-2004 Erez Zadok
 * Copyright (C) 2001-2004 Stony Brook University
 * Copyright (C) 2004-2006 International Business Machines Corp.
 *   Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
 *   		Michael C. Thompson <mcthomps@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <linux/file.h>
#include <linux/poll.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/security.h>
#include <linux/smp_lock.h>
#include <linux/compat.h>
#include "ecryptfs_kernel.h"

/**
 * ecryptfs_llseek
 * @file: File we are seeking in
 * @offset: The offset to seek to
 * @origin: 2 - offset from i_size; 1 - offset from f_pos
 *
 * Returns the position we have seeked to, or negative on error
 */
static loff_t ecryptfs_llseek(struct file *file, loff_t offset, int origin)
{
	loff_t rv;
	loff_t new_end_pos;
	int rc;
	int expanding_file = 0;
	struct inode *inode = file->f_mapping->host;

	/* If our offset is past the end of our file, we're going to
	 * need to grow it so we have a valid length of 0's */
	new_end_pos = offset;
	switch (origin) {
	case 2:
		new_end_pos += i_size_read(inode);
		expanding_file = 1;
		break;
	case 1:
		new_end_pos += file->f_pos;
		if (new_end_pos > i_size_read(inode)) {
			ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) "
					"> i_size_read(inode)(=[0x%.16x])\n",
					new_end_pos, i_size_read(inode));
			expanding_file = 1;
		}
		break;
	default:
		if (new_end_pos > i_size_read(inode)) {
			ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) "
					"> i_size_read(inode)(=[0x%.16x])\n",
					new_end_pos, i_size_read(inode));
			expanding_file = 1;
		}
	}
	ecryptfs_printk(KERN_DEBUG, "new_end_pos = [0x%.16x]\n", new_end_pos);
	if (expanding_file) {
		rc = ecryptfs_truncate(file->f_dentry, new_end_pos);
		if (rc) {
			rv = rc;
			ecryptfs_printk(KERN_ERR, "Error on attempt to "
					"truncate to (higher) offset [0x%.16x];"
					" rc = [%d]\n", new_end_pos, rc);
			goto out;
		}
	}
	rv = generic_file_llseek(file, offset, origin);
out:
	return rv;
}

/**
 * ecryptfs_read_update_atime
 *
 * generic_file_read updates the atime of upper layer inode.  But, it
 * doesn't give us a chance to update the atime of the lower layer
 * inode.  This function is a wrapper to generic_file_read.  It
 * updates the atime of the lower level inode if generic_file_read
 * returns without any errors. This is to be used only for file reads.
 * The function to be used for directory reads is ecryptfs_read.
 */
static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
				const struct iovec *iov,
				unsigned long nr_segs, loff_t pos)
{
	int rc;
	struct dentry *lower_dentry;
	struct vfsmount *lower_vfsmount;
	struct file *file = iocb->ki_filp;

	rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
	/*
	 * Even though this is a async interface, we need to wait
	 * for IO to finish to update atime
	 */
	if (-EIOCBQUEUED == rc)
		rc = wait_on_sync_kiocb(iocb);
	if (rc >= 0) {
		lower_dentry = ecryptfs_dentry_to_lower(file->f_dentry);
		lower_vfsmount = ecryptfs_dentry_to_lower_mnt(file->f_dentry);
		touch_atime(lower_vfsmount, lower_dentry);
	}
	return rc;
}

struct ecryptfs_getdents_callback {
	void *dirent;
	struct dentry *dentry;
	filldir_t filldir;
	int err;
	int filldir_called;
	int entries_written;
};

/* Inspired by generic filldir in fs/readir.c */
static int
ecryptfs_filldir(void *dirent, const char *name, int namelen, loff_t offset,
		 u64 ino, unsigned int d_type)
{
	struct ecryptfs_crypt_stat *crypt_stat;
	struct ecryptfs_getdents_callback *buf =
	    (struct ecryptfs_getdents_callback *)dirent;
	int rc;
	int decoded_length;
	char *decoded_name;

	crypt_stat = ecryptfs_dentry_to_private(buf->dentry)->crypt_stat;
	buf->filldir_called++;
	decoded_length = ecryptfs_decode_filename(crypt_stat, name, namelen,
						  &decoded_name);
	if (decoded_length < 0) {
		rc = decoded_length;
		goto out;
	}
	rc = buf->filldir(buf->dirent, decoded_name, decoded_length, offset,
			  ino, d_type);
	kfree(decoded_name);
	if (rc >= 0)
		buf->entries_written++;
out:
	return rc;
}

/**
 * ecryptfs_readdir
 * @file: The ecryptfs file struct
 * @dirent: Directory entry
 * @filldir: The filldir callback function
 */
static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir)
{
	int rc;
	struct file *lower_file;
	struct inode *inode;
	struct ecryptfs_getdents_callback buf;

	lower_file = ecryptfs_file_to_lower(file);
	lower_file->f_pos = file->f_pos;
	inode = file->f_dentry->d_inode;
	memset(&buf, 0, sizeof(buf));
	buf.dirent = dirent;
	buf.dentry = file->f_dentry;
	buf.filldir = filldir;
retry:
	buf.filldir_called = 0;
	buf.entries_written = 0;
	buf.err = 0;
	rc = vfs_readdir(lower_file, ecryptfs_filldir, (void *)&buf);
	if (buf.err)
		rc = buf.err;
	if (buf.filldir_called && !buf.entries_written)
		goto retry;
	file->f_pos = lower_file->f_pos;
	if (rc >= 0)
		ecryptfs_copy_attr_atime(inode, lower_file->f_dentry->d_inode);
	return rc;
}

struct kmem_cache *ecryptfs_file_info_cache;

/**
 * ecryptfs_open
 * @inode: inode speciying file to open
 * @file: Structure to return filled in
 *
 * Opens the file specified by inode.
 *
 * Returns zero on success; non-zero otherwise
 */
static int ecryptfs_open(struct inode *inode, struct file *file)
{
	int rc = 0;
	struct ecryptfs_crypt_stat *crypt_stat = NULL;
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
	struct dentry *ecryptfs_dentry = file->f_dentry;
	/* Private value of ecryptfs_dentry allocated in
	 * ecryptfs_lookup() */
	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
	struct inode *lower_inode = NULL;
	struct file *lower_file = NULL;
	struct vfsmount *lower_mnt;
	struct ecryptfs_file_info *file_info;
	int lower_flags;

	/* Released in ecryptfs_release or end of function if failure */
	file_info = kmem_cache_alloc(ecryptfs_file_info_cache, SLAB_KERNEL);
	ecryptfs_set_file_private(file, file_info);
	if (!file_info) {
		ecryptfs_printk(KERN_ERR,
				"Error attempting to allocate memory\n");
		rc = -ENOMEM;
		goto out;
	}
	memset(file_info, 0, sizeof(*file_info));
	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
	mount_crypt_stat = &ecryptfs_superblock_to_private(
		ecryptfs_dentry->d_sb)->mount_crypt_stat;
	mutex_lock(&crypt_stat->cs_mutex);
	if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED)) {
		ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
		/* Policy code enabled in future release */
		ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED);
		ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
	}
	mutex_unlock(&crypt_stat->cs_mutex);
	/* This mntget & dget is undone via fput when the file is released */
	dget(lower_dentry);
	lower_flags = file->f_flags;
	if ((lower_flags & O_ACCMODE) == O_WRONLY)
		lower_flags = (lower_flags & O_ACCMODE) | O_RDWR;
	if (file->f_flags & O_APPEND)
		lower_flags &= ~O_APPEND;
	lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
	mntget(lower_mnt);
	/* Corresponding fput() in ecryptfs_release() */
	lower_file = dentry_open(lower_dentry, lower_mnt, lower_flags);
	if (IS_ERR(lower_file)) {
		rc = PTR_ERR(lower_file);
		ecryptfs_printk(KERN_ERR, "Error opening lower file\n");
		goto out_puts;
	}
	ecryptfs_set_file_lower(file, lower_file);
	/* Isn't this check the same as the one in lookup? */
	lower_inode = lower_dentry->d_inode;
	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
		ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
		rc = 0;
		goto out;
	}
	mutex_lock(&crypt_stat->cs_mutex);
	if (i_size_read(lower_inode) < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) {
		if (!(mount_crypt_stat->flags
		      & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
			rc = -EIO;
			printk(KERN_WARNING "Attempt to read file that is "
			       "not in a valid eCryptfs format, and plaintext "
			       "passthrough mode is not enabled; returning "
			       "-EIO\n");
			mutex_unlock(&crypt_stat->cs_mutex);
			goto out_puts;
		}
		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
		rc = 0;
		mutex_unlock(&crypt_stat->cs_mutex);
		goto out;
	} else if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
					ECRYPTFS_POLICY_APPLIED)
		   || !ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
					   ECRYPTFS_KEY_VALID)) {
		rc = ecryptfs_read_headers(ecryptfs_dentry, lower_file);
		if (rc) {
			ecryptfs_printk(KERN_DEBUG,
					"Valid headers not found\n");
			if (!(mount_crypt_stat->flags
			      & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
				rc = -EIO;
				printk(KERN_WARNING "Attempt to read file that "
				       "is not in a valid eCryptfs format, "
				       "and plaintext passthrough mode is not "
				       "enabled; returning -EIO\n");
				mutex_unlock(&crypt_stat->cs_mutex);
				goto out_puts;
			}
			ECRYPTFS_CLEAR_FLAG(crypt_stat->flags,
					    ECRYPTFS_ENCRYPTED);
			rc = 0;
			mutex_unlock(&crypt_stat->cs_mutex);
			goto out;
		}
	}
	mutex_unlock(&crypt_stat->cs_mutex);
	ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] "
			"size: [0x%.16x]\n", inode, inode->i_ino,
			i_size_read(inode));
	ecryptfs_set_file_lower(file, lower_file);
	goto out;
out_puts:
	mntput(lower_mnt);
	dput(lower_dentry);
	kmem_cache_free(ecryptfs_file_info_cache,
			ecryptfs_file_to_private(file));
out:
	return rc;
}

static int ecryptfs_flush(struct file *file, fl_owner_t td)
{
	int rc = 0;
	struct file *lower_file = NULL;

	lower_file = ecryptfs_file_to_lower(file);
	if (lower_file->f_op && lower_file->f_op->flush)
		rc = lower_file->f_op->flush(lower_file, td);
	return rc;
}

static int ecryptfs_release(struct inode *inode, struct file *file)
{
	struct file *lower_file = ecryptfs_file_to_lower(file);
	struct ecryptfs_file_info *file_info = ecryptfs_file_to_private(file);
	struct inode *lower_inode = ecryptfs_inode_to_lower(inode);

	fput(lower_file);
	inode->i_blocks = lower_inode->i_blocks;
	kmem_cache_free(ecryptfs_file_info_cache, file_info);
	return 0;
}

static int
ecryptfs_fsync(struct file *file, struct dentry *dentry, int datasync)
{
	struct file *lower_file = ecryptfs_file_to_lower(file);
	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
	struct inode *lower_inode = lower_dentry->d_inode;
	int rc = -EINVAL;

	if (lower_inode->i_fop->fsync) {
		mutex_lock(&lower_inode->i_mutex);
		rc = lower_inode->i_fop->fsync(lower_file, lower_dentry,
					       datasync);
		mutex_unlock(&lower_inode->i_mutex);
	}
	return rc;
}

static int ecryptfs_fasync(int fd, struct file *file, int flag)
{
	int rc = 0;
	struct file *lower_file = NULL;

	lower_file = ecryptfs_file_to_lower(file);
	if (lower_file->f_op && lower_file->f_op->fasync)
		rc = lower_file->f_op->fasync(fd, lower_file, flag);
	return rc;
}

static ssize_t ecryptfs_sendfile(struct file *file, loff_t * ppos,
				 size_t count, read_actor_t actor, void *target)
{
	struct file *lower_file = NULL;
	int rc = -EINVAL;

	lower_file = ecryptfs_file_to_lower(file);
	if (lower_file->f_op && lower_file->f_op->sendfile)
		rc = lower_file->f_op->sendfile(lower_file, ppos, count,
						actor, target);

	return rc;
}

static int ecryptfs_ioctl(struct inode *inode, struct file *file,
			  unsigned int cmd, unsigned long arg);

const struct file_operations ecryptfs_dir_fops = {
	.readdir = ecryptfs_readdir,
	.ioctl = ecryptfs_ioctl,
	.mmap = generic_file_mmap,
	.open = ecryptfs_open,
	.flush = ecryptfs_flush,
	.release = ecryptfs_release,
	.fsync = ecryptfs_fsync,
	.fasync = ecryptfs_fasync,
	.sendfile = ecryptfs_sendfile,
};

const struct file_operations ecryptfs_main_fops = {
	.llseek = ecryptfs_llseek,
	.read = do_sync_read,
	.aio_read = ecryptfs_read_update_atime,
	.write = do_sync_write,
	.aio_write = generic_file_aio_write,
	.readdir = ecryptfs_readdir,
	.ioctl = ecryptfs_ioctl,
	.mmap = generic_file_mmap,
	.open = ecryptfs_open,
	.flush = ecryptfs_flush,
	.release = ecryptfs_release,
	.fsync = ecryptfs_fsync,
	.fasync = ecryptfs_fasync,
	.sendfile = ecryptfs_sendfile,
};

static int
ecryptfs_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
	       unsigned long arg)
{
	int rc = 0;
	struct file *lower_file = NULL;

	if (ecryptfs_file_to_private(file))
		lower_file = ecryptfs_file_to_lower(file);
	if (lower_file && lower_file->f_op && lower_file->f_op->ioctl)
		rc = lower_file->f_op->ioctl(ecryptfs_inode_to_lower(inode),
					     lower_file, cmd, arg);
	else
		rc = -ENOTTY;
	return rc;
}
Commit	Line	Data
237fead6 MH	1	/**
	2	* eCryptfs: Linux filesystem encryption layer
	3	*
	4	* Copyright (C) 1997-2004 Erez Zadok
	5	* Copyright (C) 2001-2004 Stony Brook University
	6	* Copyright (C) 2004-2006 International Business Machines Corp.
	7	* Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
	8	* Michael C. Thompson <mcthomps@us.ibm.com>
	9	*
	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.
	14	*
	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.
	19	*
	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.
	24	*/
	25
	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/smp_lock.h>
	32	#include <linux/compat.h>
	33	#include "ecryptfs_kernel.h"
	34
	35	/**
	36	* ecryptfs_llseek
	37	* @file: File we are seeking in
	38	* @offset: The offset to seek to
	39	* @origin: 2 - offset from i_size; 1 - offset from f_pos
	40	*
	41	* Returns the position we have seeked to, or negative on error
	42	*/
	43	static loff_t ecryptfs_llseek(struct file *file, loff_t offset, int origin)
	44	{
	45	loff_t rv;
	46	loff_t new_end_pos;
	47	int rc;
	48	int expanding_file = 0;
	49	struct inode *inode = file->f_mapping->host;
	50
	51	/* If our offset is past the end of our file, we're going to
	52	* need to grow it so we have a valid length of 0's */
	53	new_end_pos = offset;
	54	switch (origin) {
	55	case 2:
	56	new_end_pos += i_size_read(inode);
	57	expanding_file = 1;
	58	break;
	59	case 1:
	60	new_end_pos += file->f_pos;
	61	if (new_end_pos > i_size_read(inode)) {
	62	ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) "
	63	"> i_size_read(inode)(=[0x%.16x])\n",
	64	new_end_pos, i_size_read(inode));
65	expanding_file = 1;
66	}
67	break;
68	default:
69	if (new_end_pos > i_size_read(inode)) {
70	ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) "
71	"> i_size_read(inode)(=[0x%.16x])\n",
72	new_end_pos, i_size_read(inode));
73	expanding_file = 1;
74	}
75	}
76	ecryptfs_printk(KERN_DEBUG, "new_end_pos = [0x%.16x]\n", new_end_pos);
77	if (expanding_file) {
78	rc = ecryptfs_truncate(file->f_dentry, new_end_pos);
79	if (rc) {
80	rv = rc;
81	ecryptfs_printk(KERN_ERR, "Error on attempt to "
82	"truncate to (higher) offset [0x%.16x];"
83	" rc = [%d]\n", new_end_pos, rc);
84	goto out;
85	}
86	}
87	rv = generic_file_llseek(file, offset, origin);
88	out:
89	return rv;
90	}
91
92	/**
93	* ecryptfs_read_update_atime
94	*
95	* generic_file_read updates the atime of upper layer inode. But, it
96	* doesn't give us a chance to update the atime of the lower layer
97	* inode. This function is a wrapper to generic_file_read. It
98	* updates the atime of the lower level inode if generic_file_read
99	* returns without any errors. This is to be used only for file reads.
100	* The function to be used for directory reads is ecryptfs_read.
101	*/
102	static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
103	const struct iovec *iov,
104	unsigned long nr_segs, loff_t pos)
105	{
106	int rc;
107	struct dentry *lower_dentry;
108	struct vfsmount *lower_vfsmount;
109	struct file *file = iocb->ki_filp;
110
111	rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
112	/*
113	* Even though this is a async interface, we need to wait
114	* for IO to finish to update atime
115	*/
116	if (-EIOCBQUEUED == rc)
117	rc = wait_on_sync_kiocb(iocb);
118	if (rc >= 0) {
119	lower_dentry = ecryptfs_dentry_to_lower(file->f_dentry);
120	lower_vfsmount = ecryptfs_dentry_to_lower_mnt(file->f_dentry);
121	touch_atime(lower_vfsmount, lower_dentry);
122	}
123	return rc;
124	}
125
126	struct ecryptfs_getdents_callback {
127	void *dirent;
128	struct dentry *dentry;
129	filldir_t filldir;
130	int err;
131	int filldir_called;
132	int entries_written;
133	};
134
135	/* Inspired by generic filldir in fs/readir.c */
136	static int
137	ecryptfs_filldir(void dirent, const char name, int namelen, loff_t offset,
138	u64 ino, unsigned int d_type)
139	{
140	struct ecryptfs_crypt_stat *crypt_stat;
141	struct ecryptfs_getdents_callback *buf =
142	(struct ecryptfs_getdents_callback *)dirent;
143	int rc;
144	int decoded_length;
145	char *decoded_name;
146
147	crypt_stat = ecryptfs_dentry_to_private(buf->dentry)->crypt_stat;
148	buf->filldir_called++;
149	decoded_length = ecryptfs_decode_filename(crypt_stat, name, namelen,
150	&decoded_name);
151	if (decoded_length < 0) {
152	rc = decoded_length;
153	goto out;
154	}
155	rc = buf->filldir(buf->dirent, decoded_name, decoded_length, offset,
156	ino, d_type);
157	kfree(decoded_name);
158	if (rc >= 0)
159	buf->entries_written++;
160	out:
161	return rc;
162	}
163
164	/**
165	* ecryptfs_readdir
166	* @file: The ecryptfs file struct
167	* @dirent: Directory entry
168	* @filldir: The filldir callback function
169	*/
170	static int ecryptfs_readdir(struct file file, void dirent, filldir_t filldir)
171	{
172	int rc;
173	struct file *lower_file;
174	struct inode *inode;
175	struct ecryptfs_getdents_callback buf;
176
177	lower_file = ecryptfs_file_to_lower(file);
178	lower_file->f_pos = file->f_pos;
179	inode = file->f_dentry->d_inode;
180	memset(&buf, 0, sizeof(buf));
181	buf.dirent = dirent;
182	buf.dentry = file->f_dentry;
183	buf.filldir = filldir;
184	retry:
185	buf.filldir_called = 0;
186	buf.entries_written = 0;
187	buf.err = 0;
188	rc = vfs_readdir(lower_file, ecryptfs_filldir, (void *)&buf);
189	if (buf.err)
190	rc = buf.err;
191	if (buf.filldir_called && !buf.entries_written)
192	goto retry;
193	file->f_pos = lower_file->f_pos;
194	if (rc >= 0)
195	ecryptfs_copy_attr_atime(inode, lower_file->f_dentry->d_inode);
196	return rc;
197	}
198
199	struct kmem_cache *ecryptfs_file_info_cache;
200
201	/**
202	* ecryptfs_open
203	* @inode: inode speciying file to open
204	* @file: Structure to return filled in
205	*
206	* Opens the file specified by inode.
207	*
208	* Returns zero on success; non-zero otherwise
209	*/
210	static int ecryptfs_open(struct inode inode, struct file file)
211	{
212	int rc = 0;
213	struct ecryptfs_crypt_stat *crypt_stat = NULL;
214	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
215	struct dentry *ecryptfs_dentry = file->f_dentry;
216	/* Private value of ecryptfs_dentry allocated in
217	* ecryptfs_lookup() */
218	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
219	struct inode *lower_inode = NULL;
220	struct file *lower_file = NULL;
221	struct vfsmount *lower_mnt;
222	struct ecryptfs_file_info *file_info;
223	int lower_flags;
224
225	/* Released in ecryptfs_release or end of function if failure */
226	file_info = kmem_cache_alloc(ecryptfs_file_info_cache, SLAB_KERNEL);
227	ecryptfs_set_file_private(file, file_info);
228	if (!file_info) {
229	ecryptfs_printk(KERN_ERR,
230	"Error attempting to allocate memory\n");
231	rc = -ENOMEM;
232	goto out;
233	}
234	memset(file_info, 0, sizeof(*file_info));
235	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
236	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
237	mount_crypt_stat = &ecryptfs_superblock_to_private(
238	ecryptfs_dentry->d_sb)->mount_crypt_stat;
239	mutex_lock(&crypt_stat->cs_mutex);
240	if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED)) {
241	ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
242	/* Policy code enabled in future release */
243	ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED);
244	ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
245	}
246	mutex_unlock(&crypt_stat->cs_mutex);
247	/* This mntget & dget is undone via fput when the file is released */
248	dget(lower_dentry);
249	lower_flags = file->f_flags;
250	if ((lower_flags & O_ACCMODE) == O_WRONLY)
251	lower_flags = (lower_flags & O_ACCMODE) \| O_RDWR;
252	if (file->f_flags & O_APPEND)
253	lower_flags &= ~O_APPEND;
254	lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
255	mntget(lower_mnt);
256	/* Corresponding fput() in ecryptfs_release() */
257	lower_file = dentry_open(lower_dentry, lower_mnt, lower_flags);
258	if (IS_ERR(lower_file)) {
259	rc = PTR_ERR(lower_file);
260	ecryptfs_printk(KERN_ERR, "Error opening lower file\n");
261	goto out_puts;
262	}
263	ecryptfs_set_file_lower(file, lower_file);
264	/* Isn't this check the same as the one in lookup? */
265	lower_inode = lower_dentry->d_inode;
266	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
267	ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
268	ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
269	rc = 0;
270	goto out;
271	}
272	mutex_lock(&crypt_stat->cs_mutex);
273	if (i_size_read(lower_inode) < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) {
274	if (!(mount_crypt_stat->flags
275	& ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
276	rc = -EIO;
277	printk(KERN_WARNING "Attempt to read file that is "
278	"not in a valid eCryptfs format, and plaintext "
279	"passthrough mode is not enabled; returning "
280	"-EIO\n");
281	mutex_unlock(&crypt_stat->cs_mutex);
282	goto out_puts;
283	}
284	crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
285	rc = 0;
286	mutex_unlock(&crypt_stat->cs_mutex);
287	goto out;
288	} else if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
289	ECRYPTFS_POLICY_APPLIED)
290	\|\| !ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
291	ECRYPTFS_KEY_VALID)) {
292	rc = ecryptfs_read_headers(ecryptfs_dentry, lower_file);
293	if (rc) {
294	ecryptfs_printk(KERN_DEBUG,
295	"Valid headers not found\n");
296	if (!(mount_crypt_stat->flags
297	& ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
298	rc = -EIO;
299	printk(KERN_WARNING "Attempt to read file that "
300	"is not in a valid eCryptfs format, "
301	"and plaintext passthrough mode is not "
302	"enabled; returning -EIO\n");
303	mutex_unlock(&crypt_stat->cs_mutex);
304	goto out_puts;
305	}
306	ECRYPTFS_CLEAR_FLAG(crypt_stat->flags,
307	ECRYPTFS_ENCRYPTED);
308	rc = 0;
309	mutex_unlock(&crypt_stat->cs_mutex);
310	goto out;
311	}
312	}
313	mutex_unlock(&crypt_stat->cs_mutex);
314	ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] "
315	"size: [0x%.16x]\n", inode, inode->i_ino,
316	i_size_read(inode));
317	ecryptfs_set_file_lower(file, lower_file);
318	goto out;
319	out_puts:
320	mntput(lower_mnt);
321	dput(lower_dentry);
322	kmem_cache_free(ecryptfs_file_info_cache,
323	ecryptfs_file_to_private(file));
324	out:
325	return rc;
326	}
327
328	static int ecryptfs_flush(struct file *file, fl_owner_t td)
329	{
330	int rc = 0;
331	struct file *lower_file = NULL;
332
333	lower_file = ecryptfs_file_to_lower(file);
334	if (lower_file->f_op && lower_file->f_op->flush)
335	rc = lower_file->f_op->flush(lower_file, td);
336	return rc;
337	}
338
339	static int ecryptfs_release(struct inode inode, struct file file)
340	{
341	struct file *lower_file = ecryptfs_file_to_lower(file);
342	struct ecryptfs_file_info *file_info = ecryptfs_file_to_private(file);
343	struct inode *lower_inode = ecryptfs_inode_to_lower(inode);
344
345	fput(lower_file);
346	inode->i_blocks = lower_inode->i_blocks;
347	kmem_cache_free(ecryptfs_file_info_cache, file_info);
348	return 0;
349	}
350
351	static int
352	ecryptfs_fsync(struct file file, struct dentry dentry, int datasync)
353	{
354	struct file *lower_file = ecryptfs_file_to_lower(file);
355	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
356	struct inode *lower_inode = lower_dentry->d_inode;
357	int rc = -EINVAL;
358
359	if (lower_inode->i_fop->fsync) {
360	mutex_lock(&lower_inode->i_mutex);
361	rc = lower_inode->i_fop->fsync(lower_file, lower_dentry,
362	datasync);
363	mutex_unlock(&lower_inode->i_mutex);
364	}
365	return rc;
366	}
367
368	static int ecryptfs_fasync(int fd, struct file *file, int flag)
369	{
370	int rc = 0;
371	struct file *lower_file = NULL;
372
373	lower_file = ecryptfs_file_to_lower(file);
374	if (lower_file->f_op && lower_file->f_op->fasync)
375	rc = lower_file->f_op->fasync(fd, lower_file, flag);
376	return rc;
377	}
378
379	static ssize_t ecryptfs_sendfile(struct file file, loff_t ppos,
380	size_t count, read_actor_t actor, void *target)
381	{
382	struct file *lower_file = NULL;
383	int rc = -EINVAL;
384
385	lower_file = ecryptfs_file_to_lower(file);
386	if (lower_file->f_op && lower_file->f_op->sendfile)
387	rc = lower_file->f_op->sendfile(lower_file, ppos, count,
388	actor, target);
389
390	return rc;
391	}
392
393	static int ecryptfs_ioctl(struct inode inode, struct file file,
394	unsigned int cmd, unsigned long arg);
395
396	const struct file_operations ecryptfs_dir_fops = {
397	.readdir = ecryptfs_readdir,
398	.ioctl = ecryptfs_ioctl,
399	.mmap = generic_file_mmap,
400	.open = ecryptfs_open,
401	.flush = ecryptfs_flush,
402	.release = ecryptfs_release,
403	.fsync = ecryptfs_fsync,
404	.fasync = ecryptfs_fasync,
405	.sendfile = ecryptfs_sendfile,
406	};
407
408	const struct file_operations ecryptfs_main_fops = {
409	.llseek = ecryptfs_llseek,
410	.read = do_sync_read,
411	.aio_read = ecryptfs_read_update_atime,
412	.write = do_sync_write,
413	.aio_write = generic_file_aio_write,
414	.readdir = ecryptfs_readdir,
415	.ioctl = ecryptfs_ioctl,
416	.mmap = generic_file_mmap,
417	.open = ecryptfs_open,
418	.flush = ecryptfs_flush,
419	.release = ecryptfs_release,
420	.fsync = ecryptfs_fsync,
421	.fasync = ecryptfs_fasync,
422	.sendfile = ecryptfs_sendfile,
423	};
424
425	static int
426	ecryptfs_ioctl(struct inode inode, struct file file, unsigned int cmd,
427	unsigned long arg)
428	{
429	int rc = 0;
430	struct file *lower_file = NULL;
431
432	if (ecryptfs_file_to_private(file))
433	lower_file = ecryptfs_file_to_lower(file);
434	if (lower_file && lower_file->f_op && lower_file->f_op->ioctl)
435	rc = lower_file->f_op->ioctl(ecryptfs_inode_to_lower(inode),
436	lower_file, cmd, arg);
437	else
438	rc = -ENOTTY;
439	return rc;
440	}