[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) 2004-2007 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 <linux/fs_stack.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_path.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_path.dentry);
		lower_vfsmount = ecryptfs_dentry_to_lower_mnt(file->f_path.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_path.dentry->d_inode;
	memset(&buf, 0, sizeof(buf));
	buf.dirent = dirent;
	buf.dentry = file->f_path.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)
		fsstack_copy_attr_atime(inode, lower_file->f_path.dentry->d_inode);
	return rc;
}

struct kmem_cache *ecryptfs_file_info_cache;

int ecryptfs_open_lower_file(struct file **lower_file,
			     struct dentry *lower_dentry,
			     struct vfsmount *lower_mnt, int flags)
{
	int rc = 0;

	dget(lower_dentry);
	mntget(lower_mnt);
	*lower_file = dentry_open(lower_dentry, lower_mnt, flags);
	if (IS_ERR(*lower_file)) {
		printk(KERN_ERR "Error opening lower file for lower_dentry "
		       "[0x%p], lower_mnt [0x%p], and flags [0x%x]\n",
		       lower_dentry, lower_mnt, flags);
		rc = PTR_ERR(*lower_file);
		*lower_file = NULL;
		goto out;
	}
out:
	return rc;
}

int ecryptfs_close_lower_file(struct file *lower_file)
{
	fput(lower_file);
	return 0;
}

/**
 * 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_path.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;

	mount_crypt_stat = &ecryptfs_superblock_to_private(
		ecryptfs_dentry->d_sb)->mount_crypt_stat;
	if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
	    && ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR)
		|| (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC)
		|| (file->f_flags & O_APPEND))) {
		printk(KERN_WARNING "Mount has encrypted view enabled; "
		       "files may only be read\n");
		rc = -EPERM;
		goto out;
	}
	/* Released in ecryptfs_release or end of function if failure */
	file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_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;
	}
	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
	crypt_stat = &ecryptfs_inode_to_private(inode)->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);
	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);
	/* Corresponding fput() in ecryptfs_release() */
	if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
					   lower_flags))) {
		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 (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
				 ECRYPTFS_POLICY_APPLIED)
	    || !ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
				    ECRYPTFS_KEY_VALID)) {
		rc = ecryptfs_read_metadata(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);
	int rc;

	if ((rc = ecryptfs_close_lower_file(lower_file))) {
		printk(KERN_ERR "Error closing lower_file\n");
		goto out;
	}
	inode->i_blocks = lower_inode->i_blocks;
	kmem_cache_free(ecryptfs_file_info_cache, file_info);
out:
	return rc;
}

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
dd2a3b7a	6	* Copyright (C) 2004-2007 International Business Machines Corp.
237fead6 MH	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>
0cc72dc7	33	#include <linux/fs_stack.h>
237fead6 MH	34	#include "ecryptfs_kernel.h"
	35
	36	/**
	37	* ecryptfs_llseek
	38	* @file: File we are seeking in
	39	* @offset: The offset to seek to
	40	* @origin: 2 - offset from i_size; 1 - offset from f_pos
	41	*
	42	* Returns the position we have seeked to, or negative on error
	43	*/
	44	static loff_t ecryptfs_llseek(struct file *file, loff_t offset, int origin)
	45	{
	46	loff_t rv;
	47	loff_t new_end_pos;
	48	int rc;
	49	int expanding_file = 0;
	50	struct inode *inode = file->f_mapping->host;
	51
	52	/* If our offset is past the end of our file, we're going to
	53	* need to grow it so we have a valid length of 0's */
	54	new_end_pos = offset;
	55	switch (origin) {
	56	case 2:
	57	new_end_pos += i_size_read(inode);
	58	expanding_file = 1;
	59	break;
	60	case 1:
	61	new_end_pos += file->f_pos;
	62	if (new_end_pos > i_size_read(inode)) {
	63	ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) "
	64	"> i_size_read(inode)(=[0x%.16x])\n",
	65	new_end_pos, i_size_read(inode));
	66	expanding_file = 1;
	67	}
	68	break;
	69	default:
	70	if (new_end_pos > i_size_read(inode)) {
	71	ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) "
	72	"> i_size_read(inode)(=[0x%.16x])\n",
	73	new_end_pos, i_size_read(inode));
	74	expanding_file = 1;
	75	}
	76	}
	77	ecryptfs_printk(KERN_DEBUG, "new_end_pos = [0x%.16x]\n", new_end_pos);
	78	if (expanding_file) {
bd243a4b	79	rc = ecryptfs_truncate(file->f_path.dentry, new_end_pos);
237fead6 MH	80	if (rc) {
	81	rv = rc;
	82	ecryptfs_printk(KERN_ERR, "Error on attempt to "
	83	"truncate to (higher) offset [0x%.16x];"
	84	" rc = [%d]\n", new_end_pos, rc);
	85	goto out;
	86	}
	87	}
	88	rv = generic_file_llseek(file, offset, origin);
	89	out:
	90	return rv;
	91	}
	92
	93	/**
	94	* ecryptfs_read_update_atime
	95	*
	96	* generic_file_read updates the atime of upper layer inode. But, it
	97	* doesn't give us a chance to update the atime of the lower layer
	98	* inode. This function is a wrapper to generic_file_read. It
	99	* updates the atime of the lower level inode if generic_file_read
	100	* returns without any errors. This is to be used only for file reads.
	101	* The function to be used for directory reads is ecryptfs_read.
	102	*/
	103	static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
	104	const struct iovec *iov,
	105	unsigned long nr_segs, loff_t pos)
	106	{
	107	int rc;
	108	struct dentry *lower_dentry;
	109	struct vfsmount *lower_vfsmount;
	110	struct file *file = iocb->ki_filp;
	111
	112	rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
	113	/*
	114	* Even though this is a async interface, we need to wait
	115	* for IO to finish to update atime
	116	*/
	117	if (-EIOCBQUEUED == rc)
	118	rc = wait_on_sync_kiocb(iocb);
	119	if (rc >= 0) {
bd243a4b JJS	120	lower_dentry = ecryptfs_dentry_to_lower(file->f_path.dentry);
bd243a4b JJS	121	lower_vfsmount = ecryptfs_dentry_to_lower_mnt(file->f_path.dentry);
237fead6 MH	122	touch_atime(lower_vfsmount, lower_dentry);
	123	}
	124	return rc;
	125	}
	126
	127	struct ecryptfs_getdents_callback {
	128	void *dirent;
	129	struct dentry *dentry;
	130	filldir_t filldir;
	131	int err;
	132	int filldir_called;
	133	int entries_written;
	134	};
	135
	136	/* Inspired by generic filldir in fs/readir.c */
	137	static int
	138	ecryptfs_filldir(void dirent, const char name, int namelen, loff_t offset,
	139	u64 ino, unsigned int d_type)
	140	{
	141	struct ecryptfs_crypt_stat *crypt_stat;
	142	struct ecryptfs_getdents_callback *buf =
	143	(struct ecryptfs_getdents_callback *)dirent;
	144	int rc;
	145	int decoded_length;
	146	char *decoded_name;
	147
	148	crypt_stat = ecryptfs_dentry_to_private(buf->dentry)->crypt_stat;
	149	buf->filldir_called++;
	150	decoded_length = ecryptfs_decode_filename(crypt_stat, name, namelen,
	151	&decoded_name);
	152	if (decoded_length < 0) {
	153	rc = decoded_length;
	154	goto out;
	155	}
	156	rc = buf->filldir(buf->dirent, decoded_name, decoded_length, offset,
	157	ino, d_type);
	158	kfree(decoded_name);
	159	if (rc >= 0)
	160	buf->entries_written++;
	161	out:
	162	return rc;
	163	}
	164
	165	/**
	166	* ecryptfs_readdir
	167	* @file: The ecryptfs file struct
	168	* @dirent: Directory entry
	169	* @filldir: The filldir callback function
	170	*/
	171	static int ecryptfs_readdir(struct file file, void dirent, filldir_t filldir)
	172	{
	173	int rc;
	174	struct file *lower_file;
	175	struct inode *inode;
	176	struct ecryptfs_getdents_callback buf;
	177
	178	lower_file = ecryptfs_file_to_lower(file);
	179	lower_file->f_pos = file->f_pos;
bd243a4b	180	inode = file->f_path.dentry->d_inode;
237fead6 MH	181	memset(&buf, 0, sizeof(buf));
237fead6 MH	182	buf.dirent = dirent;
bd243a4b	183	buf.dentry = file->f_path.dentry;
237fead6 MH	184	buf.filldir = filldir;
	185	retry:
	186	buf.filldir_called = 0;
	187	buf.entries_written = 0;
	188	buf.err = 0;
	189	rc = vfs_readdir(lower_file, ecryptfs_filldir, (void *)&buf);
	190	if (buf.err)
	191	rc = buf.err;
	192	if (buf.filldir_called && !buf.entries_written)
	193	goto retry;
	194	file->f_pos = lower_file->f_pos;
	195	if (rc >= 0)
bd243a4b	196	fsstack_copy_attr_atime(inode, lower_file->f_path.dentry->d_inode);
237fead6 MH	197	return rc;
	198	}
	199
	200	struct kmem_cache *ecryptfs_file_info_cache;
	201
7ff1d74f MH	202	int ecryptfs_open_lower_file(struct file **lower_file,
	203	struct dentry *lower_dentry,
	204	struct vfsmount *lower_mnt, int flags)
	205	{
	206	int rc = 0;
	207
	208	dget(lower_dentry);
	209	mntget(lower_mnt);
	210	*lower_file = dentry_open(lower_dentry, lower_mnt, flags);
	211	if (IS_ERR(*lower_file)) {
	212	printk(KERN_ERR "Error opening lower file for lower_dentry "
	213	"[0x%p], lower_mnt [0x%p], and flags [0x%x]\n",
	214	lower_dentry, lower_mnt, flags);
	215	rc = PTR_ERR(*lower_file);
	216	*lower_file = NULL;
	217	goto out;
	218	}
	219	out:
	220	return rc;
	221	}
	222
	223	int ecryptfs_close_lower_file(struct file *lower_file)
	224	{
	225	fput(lower_file);
	226	return 0;
	227	}
	228
237fead6 MH	229	/**
	230	* ecryptfs_open
	231	* @inode: inode speciying file to open
	232	* @file: Structure to return filled in
	233	*
	234	* Opens the file specified by inode.
	235	*
	236	* Returns zero on success; non-zero otherwise
	237	*/
	238	static int ecryptfs_open(struct inode inode, struct file file)
	239	{
	240	int rc = 0;
	241	struct ecryptfs_crypt_stat *crypt_stat = NULL;
	242	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
bd243a4b	243	struct dentry *ecryptfs_dentry = file->f_path.dentry;
237fead6 MH	244	/* Private value of ecryptfs_dentry allocated in
	245	* ecryptfs_lookup() */
	246	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
	247	struct inode *lower_inode = NULL;
	248	struct file *lower_file = NULL;
	249	struct vfsmount *lower_mnt;
	250	struct ecryptfs_file_info *file_info;
	251	int lower_flags;
	252
e77a56dd MH	253	mount_crypt_stat = &ecryptfs_superblock_to_private(
	254	ecryptfs_dentry->d_sb)->mount_crypt_stat;
	255	if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
	256	&& ((file->f_flags & O_WRONLY) \|\| (file->f_flags & O_RDWR)
	257	\|\| (file->f_flags & O_CREAT) \|\| (file->f_flags & O_TRUNC)
	258	\|\| (file->f_flags & O_APPEND))) {
	259	printk(KERN_WARNING "Mount has encrypted view enabled; "
	260	"files may only be read\n");
	261	rc = -EPERM;
	262	goto out;
	263	}
237fead6	264	/* Released in ecryptfs_release or end of function if failure */
c3762229	265	file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
237fead6 MH	266	ecryptfs_set_file_private(file, file_info);
	267	if (!file_info) {
	268	ecryptfs_printk(KERN_ERR,
	269	"Error attempting to allocate memory\n");
	270	rc = -ENOMEM;
	271	goto out;
	272	}
237fead6 MH	273	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
237fead6 MH	274	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
237fead6 MH	275	mutex_lock(&crypt_stat->cs_mutex);
	276	if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED)) {
	277	ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
	278	/* Policy code enabled in future release */
	279	ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED);
	280	ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
	281	}
	282	mutex_unlock(&crypt_stat->cs_mutex);
237fead6 MH	283	lower_flags = file->f_flags;
	284	if ((lower_flags & O_ACCMODE) == O_WRONLY)
	285	lower_flags = (lower_flags & O_ACCMODE) \| O_RDWR;
	286	if (file->f_flags & O_APPEND)
	287	lower_flags &= ~O_APPEND;
	288	lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
237fead6	289	/* Corresponding fput() in ecryptfs_release() */
7ff1d74f MH	290	if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
7ff1d74f MH	291	lower_flags))) {
237fead6 MH	292	ecryptfs_printk(KERN_ERR, "Error opening lower file\n");
	293	goto out_puts;
	294	}
	295	ecryptfs_set_file_lower(file, lower_file);
	296	/* Isn't this check the same as the one in lookup? */
	297	lower_inode = lower_dentry->d_inode;
	298	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
	299	ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
	300	ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
	301	rc = 0;
	302	goto out;
	303	}
	304	mutex_lock(&crypt_stat->cs_mutex);
dd2a3b7a MH	305	if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
	306	ECRYPTFS_POLICY_APPLIED)
	307	\|\| !ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
	308	ECRYPTFS_KEY_VALID)) {
	309	rc = ecryptfs_read_metadata(ecryptfs_dentry, lower_file);
237fead6 MH	310	if (rc) {
	311	ecryptfs_printk(KERN_DEBUG,
	312	"Valid headers not found\n");
	313	if (!(mount_crypt_stat->flags
	314	& ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
	315	rc = -EIO;
	316	printk(KERN_WARNING "Attempt to read file that "
	317	"is not in a valid eCryptfs format, "
	318	"and plaintext passthrough mode is not "
	319	"enabled; returning -EIO\n");
	320	mutex_unlock(&crypt_stat->cs_mutex);
	321	goto out_puts;
	322	}
	323	ECRYPTFS_CLEAR_FLAG(crypt_stat->flags,
	324	ECRYPTFS_ENCRYPTED);
	325	rc = 0;
	326	mutex_unlock(&crypt_stat->cs_mutex);
	327	goto out;
	328	}
	329	}
	330	mutex_unlock(&crypt_stat->cs_mutex);
	331	ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] "
	332	"size: [0x%.16x]\n", inode, inode->i_ino,
	333	i_size_read(inode));
	334	ecryptfs_set_file_lower(file, lower_file);
	335	goto out;
	336	out_puts:
	337	mntput(lower_mnt);
	338	dput(lower_dentry);
	339	kmem_cache_free(ecryptfs_file_info_cache,
	340	ecryptfs_file_to_private(file));
	341	out:
	342	return rc;
	343	}
	344
	345	static int ecryptfs_flush(struct file *file, fl_owner_t td)
	346	{
	347	int rc = 0;
	348	struct file *lower_file = NULL;
	349
	350	lower_file = ecryptfs_file_to_lower(file);
	351	if (lower_file->f_op && lower_file->f_op->flush)
	352	rc = lower_file->f_op->flush(lower_file, td);
	353	return rc;
	354	}
	355
	356	static int ecryptfs_release(struct inode inode, struct file file)
	357	{
	358	struct file *lower_file = ecryptfs_file_to_lower(file);
	359	struct ecryptfs_file_info *file_info = ecryptfs_file_to_private(file);
	360	struct inode *lower_inode = ecryptfs_inode_to_lower(inode);
7ff1d74f	361	int rc;
237fead6	362
7ff1d74f MH	363	if ((rc = ecryptfs_close_lower_file(lower_file))) {
	364	printk(KERN_ERR "Error closing lower_file\n");
	365	goto out;
	366	}
237fead6 MH	367	inode->i_blocks = lower_inode->i_blocks;
237fead6 MH	368	kmem_cache_free(ecryptfs_file_info_cache, file_info);
7ff1d74f MH	369	out:
7ff1d74f MH	370	return rc;
237fead6 MH	371	}
	372
	373	static int
	374	ecryptfs_fsync(struct file file, struct dentry dentry, int datasync)
	375	{
	376	struct file *lower_file = ecryptfs_file_to_lower(file);
	377	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
	378	struct inode *lower_inode = lower_dentry->d_inode;
	379	int rc = -EINVAL;
	380
	381	if (lower_inode->i_fop->fsync) {
	382	mutex_lock(&lower_inode->i_mutex);
	383	rc = lower_inode->i_fop->fsync(lower_file, lower_dentry,
	384	datasync);
	385	mutex_unlock(&lower_inode->i_mutex);
	386	}
	387	return rc;
	388	}
	389
	390	static int ecryptfs_fasync(int fd, struct file *file, int flag)
	391	{
	392	int rc = 0;
	393	struct file *lower_file = NULL;
	394
	395	lower_file = ecryptfs_file_to_lower(file);
	396	if (lower_file->f_op && lower_file->f_op->fasync)
	397	rc = lower_file->f_op->fasync(fd, lower_file, flag);
	398	return rc;
	399	}
	400
	401	static ssize_t ecryptfs_sendfile(struct file file, loff_t ppos,
	402	size_t count, read_actor_t actor, void *target)
	403	{
	404	struct file *lower_file = NULL;
	405	int rc = -EINVAL;
	406
	407	lower_file = ecryptfs_file_to_lower(file);
	408	if (lower_file->f_op && lower_file->f_op->sendfile)
	409	rc = lower_file->f_op->sendfile(lower_file, ppos, count,
	410	actor, target);
	411
	412	return rc;
	413	}
	414
	415	static int ecryptfs_ioctl(struct inode inode, struct file file,
	416	unsigned int cmd, unsigned long arg);
	417
	418	const struct file_operations ecryptfs_dir_fops = {
	419	.readdir = ecryptfs_readdir,
	420	.ioctl = ecryptfs_ioctl,
	421	.mmap = generic_file_mmap,
	422	.open = ecryptfs_open,
	423	.flush = ecryptfs_flush,
	424	.release = ecryptfs_release,
	425	.fsync = ecryptfs_fsync,
	426	.fasync = ecryptfs_fasync,
	427	.sendfile = ecryptfs_sendfile,
	428	};
	429
	430	const struct file_operations ecryptfs_main_fops = {
	431	.llseek = ecryptfs_llseek,
	432	.read = do_sync_read,
	433	.aio_read = ecryptfs_read_update_atime,
	434	.write = do_sync_write,
435	.aio_write = generic_file_aio_write,
436	.readdir = ecryptfs_readdir,
437	.ioctl = ecryptfs_ioctl,
438	.mmap = generic_file_mmap,
439	.open = ecryptfs_open,
440	.flush = ecryptfs_flush,
441	.release = ecryptfs_release,
442	.fsync = ecryptfs_fsync,
443	.fasync = ecryptfs_fasync,
444	.sendfile = ecryptfs_sendfile,
445	};
446
447	static int
448	ecryptfs_ioctl(struct inode inode, struct file file, unsigned int cmd,
449	unsigned long arg)
450	{
451	int rc = 0;
452	struct file *lower_file = NULL;
453
454	if (ecryptfs_file_to_private(file))
455	lower_file = ecryptfs_file_to_lower(file);
456	if (lower_file && lower_file->f_op && lower_file->f_op->ioctl)
457	rc = lower_file->f_op->ioctl(ecryptfs_inode_to_lower(inode),
458	lower_file, cmd, arg);
459	else
460	rc = -ENOTTY;
461	return rc;
462	}