1237fead6SMichael Halcrow /** 2237fead6SMichael Halcrow * eCryptfs: Linux filesystem encryption layer 3237fead6SMichael Halcrow * 4237fead6SMichael Halcrow * Copyright (C) 1997-2004 Erez Zadok 5237fead6SMichael Halcrow * Copyright (C) 2001-2004 Stony Brook University 6237fead6SMichael Halcrow * Copyright (C) 2004-2006 International Business Machines Corp. 7237fead6SMichael Halcrow * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> 8237fead6SMichael Halcrow * Michael C. Thompsion <mcthomps@us.ibm.com> 9237fead6SMichael Halcrow * 10237fead6SMichael Halcrow * This program is free software; you can redistribute it and/or 11237fead6SMichael Halcrow * modify it under the terms of the GNU General Public License as 12237fead6SMichael Halcrow * published by the Free Software Foundation; either version 2 of the 13237fead6SMichael Halcrow * License, or (at your option) any later version. 14237fead6SMichael Halcrow * 15237fead6SMichael Halcrow * This program is distributed in the hope that it will be useful, but 16237fead6SMichael Halcrow * WITHOUT ANY WARRANTY; without even the implied warranty of 17237fead6SMichael Halcrow * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18237fead6SMichael Halcrow * General Public License for more details. 19237fead6SMichael Halcrow * 20237fead6SMichael Halcrow * You should have received a copy of the GNU General Public License 21237fead6SMichael Halcrow * along with this program; if not, write to the Free Software 22237fead6SMichael Halcrow * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 23237fead6SMichael Halcrow * 02111-1307, USA. 24237fead6SMichael Halcrow */ 25237fead6SMichael Halcrow 26237fead6SMichael Halcrow #include <linux/file.h> 27237fead6SMichael Halcrow #include <linux/vmalloc.h> 28237fead6SMichael Halcrow #include <linux/pagemap.h> 29237fead6SMichael Halcrow #include <linux/dcache.h> 30237fead6SMichael Halcrow #include <linux/namei.h> 31237fead6SMichael Halcrow #include <linux/mount.h> 32237fead6SMichael Halcrow #include <linux/crypto.h> 330cc72dc7SJosef "Jeff" Sipek #include <linux/fs_stack.h> 34237fead6SMichael Halcrow #include "ecryptfs_kernel.h" 35237fead6SMichael Halcrow 36237fead6SMichael Halcrow static struct dentry *lock_parent(struct dentry *dentry) 37237fead6SMichael Halcrow { 38237fead6SMichael Halcrow struct dentry *dir; 39237fead6SMichael Halcrow 40237fead6SMichael Halcrow dir = dget(dentry->d_parent); 41237fead6SMichael Halcrow mutex_lock(&(dir->d_inode->i_mutex)); 42237fead6SMichael Halcrow return dir; 43237fead6SMichael Halcrow } 44237fead6SMichael Halcrow 45237fead6SMichael Halcrow static void unlock_parent(struct dentry *dentry) 46237fead6SMichael Halcrow { 47237fead6SMichael Halcrow mutex_unlock(&(dentry->d_parent->d_inode->i_mutex)); 48237fead6SMichael Halcrow dput(dentry->d_parent); 49237fead6SMichael Halcrow } 50237fead6SMichael Halcrow 51237fead6SMichael Halcrow static void unlock_dir(struct dentry *dir) 52237fead6SMichael Halcrow { 53237fead6SMichael Halcrow mutex_unlock(&dir->d_inode->i_mutex); 54237fead6SMichael Halcrow dput(dir); 55237fead6SMichael Halcrow } 56237fead6SMichael Halcrow 57237fead6SMichael Halcrow /** 58237fead6SMichael Halcrow * ecryptfs_create_underlying_file 59237fead6SMichael Halcrow * @lower_dir_inode: inode of the parent in the lower fs of the new file 60237fead6SMichael Halcrow * @lower_dentry: New file's dentry in the lower fs 61237fead6SMichael Halcrow * @ecryptfs_dentry: New file's dentry in ecryptfs 62237fead6SMichael Halcrow * @mode: The mode of the new file 63237fead6SMichael Halcrow * @nd: nameidata of ecryptfs' parent's dentry & vfsmount 64237fead6SMichael Halcrow * 65237fead6SMichael Halcrow * Creates the file in the lower file system. 66237fead6SMichael Halcrow * 67237fead6SMichael Halcrow * Returns zero on success; non-zero on error condition 68237fead6SMichael Halcrow */ 69237fead6SMichael Halcrow static int 70237fead6SMichael Halcrow ecryptfs_create_underlying_file(struct inode *lower_dir_inode, 71237fead6SMichael Halcrow struct dentry *dentry, int mode, 72237fead6SMichael Halcrow struct nameidata *nd) 73237fead6SMichael Halcrow { 74237fead6SMichael Halcrow struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); 75237fead6SMichael Halcrow struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); 76237fead6SMichael Halcrow struct dentry *dentry_save; 77237fead6SMichael Halcrow struct vfsmount *vfsmount_save; 78237fead6SMichael Halcrow int rc; 79237fead6SMichael Halcrow 80237fead6SMichael Halcrow dentry_save = nd->dentry; 81237fead6SMichael Halcrow vfsmount_save = nd->mnt; 82237fead6SMichael Halcrow nd->dentry = lower_dentry; 83237fead6SMichael Halcrow nd->mnt = lower_mnt; 84237fead6SMichael Halcrow rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd); 85237fead6SMichael Halcrow nd->dentry = dentry_save; 86237fead6SMichael Halcrow nd->mnt = vfsmount_save; 87237fead6SMichael Halcrow return rc; 88237fead6SMichael Halcrow } 89237fead6SMichael Halcrow 90237fead6SMichael Halcrow /** 91237fead6SMichael Halcrow * ecryptfs_do_create 92237fead6SMichael Halcrow * @directory_inode: inode of the new file's dentry's parent in ecryptfs 93237fead6SMichael Halcrow * @ecryptfs_dentry: New file's dentry in ecryptfs 94237fead6SMichael Halcrow * @mode: The mode of the new file 95237fead6SMichael Halcrow * @nd: nameidata of ecryptfs' parent's dentry & vfsmount 96237fead6SMichael Halcrow * 97237fead6SMichael Halcrow * Creates the underlying file and the eCryptfs inode which will link to 98237fead6SMichael Halcrow * it. It will also update the eCryptfs directory inode to mimic the 99237fead6SMichael Halcrow * stat of the lower directory inode. 100237fead6SMichael Halcrow * 101237fead6SMichael Halcrow * Returns zero on success; non-zero on error condition 102237fead6SMichael Halcrow */ 103237fead6SMichael Halcrow static int 104237fead6SMichael Halcrow ecryptfs_do_create(struct inode *directory_inode, 105237fead6SMichael Halcrow struct dentry *ecryptfs_dentry, int mode, 106237fead6SMichael Halcrow struct nameidata *nd) 107237fead6SMichael Halcrow { 108237fead6SMichael Halcrow int rc; 109237fead6SMichael Halcrow struct dentry *lower_dentry; 110237fead6SMichael Halcrow struct dentry *lower_dir_dentry; 111237fead6SMichael Halcrow 112237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 113237fead6SMichael Halcrow lower_dir_dentry = lock_parent(lower_dentry); 114237fead6SMichael Halcrow if (unlikely(IS_ERR(lower_dir_dentry))) { 115237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, "Error locking directory of " 116237fead6SMichael Halcrow "dentry\n"); 117237fead6SMichael Halcrow rc = PTR_ERR(lower_dir_dentry); 118237fead6SMichael Halcrow goto out; 119237fead6SMichael Halcrow } 120237fead6SMichael Halcrow rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode, 121237fead6SMichael Halcrow ecryptfs_dentry, mode, nd); 122237fead6SMichael Halcrow if (unlikely(rc)) { 123237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, 124237fead6SMichael Halcrow "Failure to create underlying file\n"); 125237fead6SMichael Halcrow goto out_lock; 126237fead6SMichael Halcrow } 127237fead6SMichael Halcrow rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry, 128237fead6SMichael Halcrow directory_inode->i_sb, 0); 129237fead6SMichael Halcrow if (rc) { 130237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n"); 131237fead6SMichael Halcrow goto out_lock; 132237fead6SMichael Halcrow } 1330cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode); 1340cc72dc7SJosef "Jeff" Sipek fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode); 135237fead6SMichael Halcrow out_lock: 136237fead6SMichael Halcrow unlock_dir(lower_dir_dentry); 137237fead6SMichael Halcrow out: 138237fead6SMichael Halcrow return rc; 139237fead6SMichael Halcrow } 140237fead6SMichael Halcrow 141237fead6SMichael Halcrow /** 142237fead6SMichael Halcrow * grow_file 143237fead6SMichael Halcrow * @ecryptfs_dentry: the ecryptfs dentry 144237fead6SMichael Halcrow * @lower_file: The lower file 145237fead6SMichael Halcrow * @inode: The ecryptfs inode 146237fead6SMichael Halcrow * @lower_inode: The lower inode 147237fead6SMichael Halcrow * 148237fead6SMichael Halcrow * This is the code which will grow the file to its correct size. 149237fead6SMichael Halcrow */ 150237fead6SMichael Halcrow static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file, 151237fead6SMichael Halcrow struct inode *inode, struct inode *lower_inode) 152237fead6SMichael Halcrow { 153237fead6SMichael Halcrow int rc = 0; 154237fead6SMichael Halcrow struct file fake_file; 155237fead6SMichael Halcrow struct ecryptfs_file_info tmp_file_info; 156237fead6SMichael Halcrow 157237fead6SMichael Halcrow memset(&fake_file, 0, sizeof(fake_file)); 158bd243a4bSJosef "Jeff" Sipek fake_file.f_path.dentry = ecryptfs_dentry; 159237fead6SMichael Halcrow memset(&tmp_file_info, 0, sizeof(tmp_file_info)); 160237fead6SMichael Halcrow ecryptfs_set_file_private(&fake_file, &tmp_file_info); 161237fead6SMichael Halcrow ecryptfs_set_file_lower(&fake_file, lower_file); 162237fead6SMichael Halcrow rc = ecryptfs_fill_zeros(&fake_file, 1); 163237fead6SMichael Halcrow if (rc) { 164237fead6SMichael Halcrow ECRYPTFS_SET_FLAG( 165237fead6SMichael Halcrow ecryptfs_inode_to_private(inode)->crypt_stat.flags, 166237fead6SMichael Halcrow ECRYPTFS_SECURITY_WARNING); 167237fead6SMichael Halcrow ecryptfs_printk(KERN_WARNING, "Error attempting to fill zeros " 168237fead6SMichael Halcrow "in file; rc = [%d]\n", rc); 169237fead6SMichael Halcrow goto out; 170237fead6SMichael Halcrow } 171237fead6SMichael Halcrow i_size_write(inode, 0); 172237fead6SMichael Halcrow ecryptfs_write_inode_size_to_header(lower_file, lower_inode, inode); 173237fead6SMichael Halcrow ECRYPTFS_SET_FLAG(ecryptfs_inode_to_private(inode)->crypt_stat.flags, 174237fead6SMichael Halcrow ECRYPTFS_NEW_FILE); 175237fead6SMichael Halcrow out: 176237fead6SMichael Halcrow return rc; 177237fead6SMichael Halcrow } 178237fead6SMichael Halcrow 179237fead6SMichael Halcrow /** 180237fead6SMichael Halcrow * ecryptfs_initialize_file 181237fead6SMichael Halcrow * 182237fead6SMichael Halcrow * Cause the file to be changed from a basic empty file to an ecryptfs 183237fead6SMichael Halcrow * file with a header and first data page. 184237fead6SMichael Halcrow * 185237fead6SMichael Halcrow * Returns zero on success 186237fead6SMichael Halcrow */ 187237fead6SMichael Halcrow static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) 188237fead6SMichael Halcrow { 189237fead6SMichael Halcrow int rc = 0; 190237fead6SMichael Halcrow int lower_flags; 191237fead6SMichael Halcrow struct ecryptfs_crypt_stat *crypt_stat; 192237fead6SMichael Halcrow struct dentry *lower_dentry; 193237fead6SMichael Halcrow struct file *lower_file; 194237fead6SMichael Halcrow struct inode *inode, *lower_inode; 195237fead6SMichael Halcrow struct vfsmount *lower_mnt; 196237fead6SMichael Halcrow 197237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 198237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "lower_dentry->d_name.name = [%s]\n", 199237fead6SMichael Halcrow lower_dentry->d_name.name); 200237fead6SMichael Halcrow inode = ecryptfs_dentry->d_inode; 201237fead6SMichael Halcrow crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; 202237fead6SMichael Halcrow lower_flags = ((O_CREAT | O_WRONLY | O_TRUNC) & O_ACCMODE) | O_RDWR; 203237fead6SMichael Halcrow #if BITS_PER_LONG != 32 204237fead6SMichael Halcrow lower_flags |= O_LARGEFILE; 205237fead6SMichael Halcrow #endif 206237fead6SMichael Halcrow lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); 207237fead6SMichael Halcrow /* Corresponding fput() at end of this function */ 2087ff1d74fSMichael Halcrow if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt, 2097ff1d74fSMichael Halcrow lower_flags))) { 210237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, 211237fead6SMichael Halcrow "Error opening dentry; rc = [%i]\n", rc); 212237fead6SMichael Halcrow goto out; 213237fead6SMichael Halcrow } 2147ff1d74fSMichael Halcrow lower_inode = lower_dentry->d_inode; 215237fead6SMichael Halcrow if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { 216237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "This is a directory\n"); 217237fead6SMichael Halcrow ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED); 218237fead6SMichael Halcrow goto out_fput; 219237fead6SMichael Halcrow } 220237fead6SMichael Halcrow ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE); 221237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n"); 222237fead6SMichael Halcrow rc = ecryptfs_new_file_context(ecryptfs_dentry); 223237fead6SMichael Halcrow if (rc) { 224237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "Error creating new file " 225237fead6SMichael Halcrow "context\n"); 226237fead6SMichael Halcrow goto out_fput; 227237fead6SMichael Halcrow } 228237fead6SMichael Halcrow rc = ecryptfs_write_headers(ecryptfs_dentry, lower_file); 229237fead6SMichael Halcrow if (rc) { 230237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "Error writing headers\n"); 231237fead6SMichael Halcrow goto out_fput; 232237fead6SMichael Halcrow } 233237fead6SMichael Halcrow rc = grow_file(ecryptfs_dentry, lower_file, inode, lower_inode); 234237fead6SMichael Halcrow out_fput: 2357ff1d74fSMichael Halcrow if ((rc = ecryptfs_close_lower_file(lower_file))) 2367ff1d74fSMichael Halcrow printk(KERN_ERR "Error closing lower_file\n"); 237237fead6SMichael Halcrow out: 238237fead6SMichael Halcrow return rc; 239237fead6SMichael Halcrow } 240237fead6SMichael Halcrow 241237fead6SMichael Halcrow /** 242237fead6SMichael Halcrow * ecryptfs_create 243237fead6SMichael Halcrow * @dir: The inode of the directory in which to create the file. 244237fead6SMichael Halcrow * @dentry: The eCryptfs dentry 245237fead6SMichael Halcrow * @mode: The mode of the new file. 246237fead6SMichael Halcrow * @nd: nameidata 247237fead6SMichael Halcrow * 248237fead6SMichael Halcrow * Creates a new file. 249237fead6SMichael Halcrow * 250237fead6SMichael Halcrow * Returns zero on success; non-zero on error condition 251237fead6SMichael Halcrow */ 252237fead6SMichael Halcrow static int 253237fead6SMichael Halcrow ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry, 254237fead6SMichael Halcrow int mode, struct nameidata *nd) 255237fead6SMichael Halcrow { 256237fead6SMichael Halcrow int rc; 257237fead6SMichael Halcrow 258237fead6SMichael Halcrow rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd); 259237fead6SMichael Halcrow if (unlikely(rc)) { 260237fead6SMichael Halcrow ecryptfs_printk(KERN_WARNING, "Failed to create file in" 261237fead6SMichael Halcrow "lower filesystem\n"); 262237fead6SMichael Halcrow goto out; 263237fead6SMichael Halcrow } 264237fead6SMichael Halcrow /* At this point, a file exists on "disk"; we need to make sure 265237fead6SMichael Halcrow * that this on disk file is prepared to be an ecryptfs file */ 266237fead6SMichael Halcrow rc = ecryptfs_initialize_file(ecryptfs_dentry); 267237fead6SMichael Halcrow out: 268237fead6SMichael Halcrow return rc; 269237fead6SMichael Halcrow } 270237fead6SMichael Halcrow 271237fead6SMichael Halcrow /** 272237fead6SMichael Halcrow * ecryptfs_lookup 273237fead6SMichael Halcrow * @dir: inode 274237fead6SMichael Halcrow * @dentry: The dentry 275237fead6SMichael Halcrow * @nd: nameidata, may be NULL 276237fead6SMichael Halcrow * 277237fead6SMichael Halcrow * Find a file on disk. If the file does not exist, then we'll add it to the 278237fead6SMichael Halcrow * dentry cache and continue on to read it from the disk. 279237fead6SMichael Halcrow */ 280237fead6SMichael Halcrow static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, 281237fead6SMichael Halcrow struct nameidata *nd) 282237fead6SMichael Halcrow { 283237fead6SMichael Halcrow int rc = 0; 284237fead6SMichael Halcrow struct dentry *lower_dir_dentry; 285237fead6SMichael Halcrow struct dentry *lower_dentry; 286237fead6SMichael Halcrow struct vfsmount *lower_mnt; 287237fead6SMichael Halcrow char *encoded_name; 288237fead6SMichael Halcrow unsigned int encoded_namelen; 289237fead6SMichael Halcrow struct ecryptfs_crypt_stat *crypt_stat = NULL; 290237fead6SMichael Halcrow char *page_virt = NULL; 291237fead6SMichael Halcrow struct inode *lower_inode; 292237fead6SMichael Halcrow u64 file_size; 293237fead6SMichael Halcrow 294237fead6SMichael Halcrow lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent); 295237fead6SMichael Halcrow dentry->d_op = &ecryptfs_dops; 296237fead6SMichael Halcrow if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, ".")) 29745ec4abaSMichael Halcrow || (dentry->d_name.len == 2 29845ec4abaSMichael Halcrow && !strcmp(dentry->d_name.name, ".."))) { 29945ec4abaSMichael Halcrow d_drop(dentry); 30045ec4abaSMichael Halcrow goto out; 30145ec4abaSMichael Halcrow } 302237fead6SMichael Halcrow encoded_namelen = ecryptfs_encode_filename(crypt_stat, 303237fead6SMichael Halcrow dentry->d_name.name, 304237fead6SMichael Halcrow dentry->d_name.len, 305237fead6SMichael Halcrow &encoded_name); 306237fead6SMichael Halcrow if (encoded_namelen < 0) { 307237fead6SMichael Halcrow rc = encoded_namelen; 30845ec4abaSMichael Halcrow d_drop(dentry); 30945ec4abaSMichael Halcrow goto out; 310237fead6SMichael Halcrow } 311237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen " 312237fead6SMichael Halcrow "= [%d]\n", encoded_name, encoded_namelen); 313237fead6SMichael Halcrow lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry, 314237fead6SMichael Halcrow encoded_namelen - 1); 315237fead6SMichael Halcrow kfree(encoded_name); 316237fead6SMichael Halcrow if (IS_ERR(lower_dentry)) { 317237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n"); 318237fead6SMichael Halcrow rc = PTR_ERR(lower_dentry); 31945ec4abaSMichael Halcrow d_drop(dentry); 32045ec4abaSMichael Halcrow goto out; 321237fead6SMichael Halcrow } 32245ec4abaSMichael Halcrow lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent)); 323237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->" 324237fead6SMichael Halcrow "d_name.name = [%s]\n", lower_dentry, 325237fead6SMichael Halcrow lower_dentry->d_name.name); 326237fead6SMichael Halcrow lower_inode = lower_dentry->d_inode; 3270cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_atime(dir, lower_dir_dentry->d_inode); 328237fead6SMichael Halcrow BUG_ON(!atomic_read(&lower_dentry->d_count)); 329237fead6SMichael Halcrow ecryptfs_set_dentry_private(dentry, 330237fead6SMichael Halcrow kmem_cache_alloc(ecryptfs_dentry_info_cache, 331e94b1766SChristoph Lameter GFP_KERNEL)); 332237fead6SMichael Halcrow if (!ecryptfs_dentry_to_private(dentry)) { 333237fead6SMichael Halcrow rc = -ENOMEM; 334237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting " 335237fead6SMichael Halcrow "to allocate ecryptfs_dentry_info struct\n"); 336237fead6SMichael Halcrow goto out_dput; 337237fead6SMichael Halcrow } 338237fead6SMichael Halcrow ecryptfs_set_dentry_lower(dentry, lower_dentry); 339237fead6SMichael Halcrow ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt); 340237fead6SMichael Halcrow if (!lower_dentry->d_inode) { 341237fead6SMichael Halcrow /* We want to add because we couldn't find in lower */ 342237fead6SMichael Halcrow d_add(dentry, NULL); 343237fead6SMichael Halcrow goto out; 344237fead6SMichael Halcrow } 345237fead6SMichael Halcrow rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 1); 346237fead6SMichael Halcrow if (rc) { 347237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, "Error interposing\n"); 348237fead6SMichael Halcrow goto out_dput; 349237fead6SMichael Halcrow } 350237fead6SMichael Halcrow if (S_ISDIR(lower_inode->i_mode)) { 351237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n"); 352237fead6SMichael Halcrow goto out; 353237fead6SMichael Halcrow } 354237fead6SMichael Halcrow if (S_ISLNK(lower_inode->i_mode)) { 355237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n"); 356237fead6SMichael Halcrow goto out; 357237fead6SMichael Halcrow } 358237fead6SMichael Halcrow if (!nd) { 359237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave" 360237fead6SMichael Halcrow "as we *think* we are about to unlink\n"); 361237fead6SMichael Halcrow goto out; 362237fead6SMichael Halcrow } 363237fead6SMichael Halcrow /* Released in this function */ 364237fead6SMichael Halcrow page_virt = 365237fead6SMichael Halcrow (char *)kmem_cache_alloc(ecryptfs_header_cache_2, 366f7267c0cSChristoph Lameter GFP_USER); 367237fead6SMichael Halcrow if (!page_virt) { 368237fead6SMichael Halcrow rc = -ENOMEM; 369237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, 370237fead6SMichael Halcrow "Cannot ecryptfs_kmalloc a page\n"); 371237fead6SMichael Halcrow goto out_dput; 372237fead6SMichael Halcrow } 373237fead6SMichael Halcrow memset(page_virt, 0, PAGE_CACHE_SIZE); 37445ec4abaSMichael Halcrow rc = ecryptfs_read_header_region(page_virt, lower_dentry, nd->mnt); 375237fead6SMichael Halcrow crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; 376237fead6SMichael Halcrow if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED)) 377237fead6SMichael Halcrow ecryptfs_set_default_sizes(crypt_stat); 378237fead6SMichael Halcrow if (rc) { 379237fead6SMichael Halcrow rc = 0; 380237fead6SMichael Halcrow ecryptfs_printk(KERN_WARNING, "Error reading header region;" 381237fead6SMichael Halcrow " assuming unencrypted\n"); 382237fead6SMichael Halcrow } else { 383237fead6SMichael Halcrow if (!contains_ecryptfs_marker(page_virt 384237fead6SMichael Halcrow + ECRYPTFS_FILE_SIZE_BYTES)) { 385237fead6SMichael Halcrow kmem_cache_free(ecryptfs_header_cache_2, page_virt); 386237fead6SMichael Halcrow goto out; 387237fead6SMichael Halcrow } 388237fead6SMichael Halcrow memcpy(&file_size, page_virt, sizeof(file_size)); 389237fead6SMichael Halcrow file_size = be64_to_cpu(file_size); 390237fead6SMichael Halcrow i_size_write(dentry->d_inode, (loff_t)file_size); 391237fead6SMichael Halcrow } 392237fead6SMichael Halcrow kmem_cache_free(ecryptfs_header_cache_2, page_virt); 393237fead6SMichael Halcrow goto out; 394237fead6SMichael Halcrow 395237fead6SMichael Halcrow out_dput: 396237fead6SMichael Halcrow dput(lower_dentry); 397237fead6SMichael Halcrow d_drop(dentry); 398237fead6SMichael Halcrow out: 399237fead6SMichael Halcrow return ERR_PTR(rc); 400237fead6SMichael Halcrow } 401237fead6SMichael Halcrow 402237fead6SMichael Halcrow static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, 403237fead6SMichael Halcrow struct dentry *new_dentry) 404237fead6SMichael Halcrow { 405237fead6SMichael Halcrow struct dentry *lower_old_dentry; 406237fead6SMichael Halcrow struct dentry *lower_new_dentry; 407237fead6SMichael Halcrow struct dentry *lower_dir_dentry; 408237fead6SMichael Halcrow u64 file_size_save; 409237fead6SMichael Halcrow int rc; 410237fead6SMichael Halcrow 411237fead6SMichael Halcrow file_size_save = i_size_read(old_dentry->d_inode); 412237fead6SMichael Halcrow lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry); 413237fead6SMichael Halcrow lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry); 414237fead6SMichael Halcrow dget(lower_old_dentry); 415237fead6SMichael Halcrow dget(lower_new_dentry); 416237fead6SMichael Halcrow lower_dir_dentry = lock_parent(lower_new_dentry); 417237fead6SMichael Halcrow rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode, 418237fead6SMichael Halcrow lower_new_dentry); 419237fead6SMichael Halcrow if (rc || !lower_new_dentry->d_inode) 420237fead6SMichael Halcrow goto out_lock; 421237fead6SMichael Halcrow rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0); 422237fead6SMichael Halcrow if (rc) 423237fead6SMichael Halcrow goto out_lock; 4240cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_times(dir, lower_new_dentry->d_inode); 4250cc72dc7SJosef "Jeff" Sipek fsstack_copy_inode_size(dir, lower_new_dentry->d_inode); 426237fead6SMichael Halcrow old_dentry->d_inode->i_nlink = 427237fead6SMichael Halcrow ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink; 428237fead6SMichael Halcrow i_size_write(new_dentry->d_inode, file_size_save); 429237fead6SMichael Halcrow out_lock: 430237fead6SMichael Halcrow unlock_dir(lower_dir_dentry); 431237fead6SMichael Halcrow dput(lower_new_dentry); 432237fead6SMichael Halcrow dput(lower_old_dentry); 433ae56fb16SMichael Halcrow d_drop(lower_old_dentry); 434237fead6SMichael Halcrow d_drop(new_dentry); 43545ec4abaSMichael Halcrow d_drop(old_dentry); 436237fead6SMichael Halcrow return rc; 437237fead6SMichael Halcrow } 438237fead6SMichael Halcrow 439237fead6SMichael Halcrow static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry) 440237fead6SMichael Halcrow { 441237fead6SMichael Halcrow int rc = 0; 442237fead6SMichael Halcrow struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); 443237fead6SMichael Halcrow struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir); 444237fead6SMichael Halcrow 445237fead6SMichael Halcrow lock_parent(lower_dentry); 446237fead6SMichael Halcrow rc = vfs_unlink(lower_dir_inode, lower_dentry); 447237fead6SMichael Halcrow if (rc) { 448ae56fb16SMichael Halcrow printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc); 449237fead6SMichael Halcrow goto out_unlock; 450237fead6SMichael Halcrow } 4510cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_times(dir, lower_dir_inode); 452237fead6SMichael Halcrow dentry->d_inode->i_nlink = 453237fead6SMichael Halcrow ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink; 454237fead6SMichael Halcrow dentry->d_inode->i_ctime = dir->i_ctime; 455237fead6SMichael Halcrow out_unlock: 456237fead6SMichael Halcrow unlock_parent(lower_dentry); 457237fead6SMichael Halcrow return rc; 458237fead6SMichael Halcrow } 459237fead6SMichael Halcrow 460237fead6SMichael Halcrow static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry, 461237fead6SMichael Halcrow const char *symname) 462237fead6SMichael Halcrow { 463237fead6SMichael Halcrow int rc; 464237fead6SMichael Halcrow struct dentry *lower_dentry; 465237fead6SMichael Halcrow struct dentry *lower_dir_dentry; 466237fead6SMichael Halcrow umode_t mode; 467237fead6SMichael Halcrow char *encoded_symname; 468237fead6SMichael Halcrow unsigned int encoded_symlen; 469237fead6SMichael Halcrow struct ecryptfs_crypt_stat *crypt_stat = NULL; 470237fead6SMichael Halcrow 471237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 472237fead6SMichael Halcrow dget(lower_dentry); 473237fead6SMichael Halcrow lower_dir_dentry = lock_parent(lower_dentry); 474237fead6SMichael Halcrow mode = S_IALLUGO; 475237fead6SMichael Halcrow encoded_symlen = ecryptfs_encode_filename(crypt_stat, symname, 476237fead6SMichael Halcrow strlen(symname), 477237fead6SMichael Halcrow &encoded_symname); 478237fead6SMichael Halcrow if (encoded_symlen < 0) { 479237fead6SMichael Halcrow rc = encoded_symlen; 480237fead6SMichael Halcrow goto out_lock; 481237fead6SMichael Halcrow } 482237fead6SMichael Halcrow rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry, 483237fead6SMichael Halcrow encoded_symname, mode); 484237fead6SMichael Halcrow kfree(encoded_symname); 485237fead6SMichael Halcrow if (rc || !lower_dentry->d_inode) 486237fead6SMichael Halcrow goto out_lock; 487237fead6SMichael Halcrow rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); 488237fead6SMichael Halcrow if (rc) 489237fead6SMichael Halcrow goto out_lock; 4900cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); 4910cc72dc7SJosef "Jeff" Sipek fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode); 492237fead6SMichael Halcrow out_lock: 493237fead6SMichael Halcrow unlock_dir(lower_dir_dentry); 494237fead6SMichael Halcrow dput(lower_dentry); 495237fead6SMichael Halcrow if (!dentry->d_inode) 496237fead6SMichael Halcrow d_drop(dentry); 497237fead6SMichael Halcrow return rc; 498237fead6SMichael Halcrow } 499237fead6SMichael Halcrow 500237fead6SMichael Halcrow static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 501237fead6SMichael Halcrow { 502237fead6SMichael Halcrow int rc; 503237fead6SMichael Halcrow struct dentry *lower_dentry; 504237fead6SMichael Halcrow struct dentry *lower_dir_dentry; 505237fead6SMichael Halcrow 506237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 507237fead6SMichael Halcrow lower_dir_dentry = lock_parent(lower_dentry); 508237fead6SMichael Halcrow rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode); 509237fead6SMichael Halcrow if (rc || !lower_dentry->d_inode) 510237fead6SMichael Halcrow goto out; 511237fead6SMichael Halcrow rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); 512237fead6SMichael Halcrow if (rc) 513237fead6SMichael Halcrow goto out; 5140cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); 5150cc72dc7SJosef "Jeff" Sipek fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode); 516237fead6SMichael Halcrow dir->i_nlink = lower_dir_dentry->d_inode->i_nlink; 517237fead6SMichael Halcrow out: 518237fead6SMichael Halcrow unlock_dir(lower_dir_dentry); 519237fead6SMichael Halcrow if (!dentry->d_inode) 520237fead6SMichael Halcrow d_drop(dentry); 521237fead6SMichael Halcrow return rc; 522237fead6SMichael Halcrow } 523237fead6SMichael Halcrow 524237fead6SMichael Halcrow static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry) 525237fead6SMichael Halcrow { 526237fead6SMichael Halcrow struct dentry *lower_dentry; 527237fead6SMichael Halcrow struct dentry *lower_dir_dentry; 52845ec4abaSMichael Halcrow int rc; 529237fead6SMichael Halcrow 530237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 53145ec4abaSMichael Halcrow dget(dentry); 532237fead6SMichael Halcrow lower_dir_dentry = lock_parent(lower_dentry); 53345ec4abaSMichael Halcrow dget(lower_dentry); 534237fead6SMichael Halcrow rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry); 53545ec4abaSMichael Halcrow dput(lower_dentry); 53645ec4abaSMichael Halcrow if (!rc) 53745ec4abaSMichael Halcrow d_delete(lower_dentry); 5380cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); 539237fead6SMichael Halcrow dir->i_nlink = lower_dir_dentry->d_inode->i_nlink; 540237fead6SMichael Halcrow unlock_dir(lower_dir_dentry); 541237fead6SMichael Halcrow if (!rc) 542237fead6SMichael Halcrow d_drop(dentry); 54345ec4abaSMichael Halcrow dput(dentry); 544237fead6SMichael Halcrow return rc; 545237fead6SMichael Halcrow } 546237fead6SMichael Halcrow 547237fead6SMichael Halcrow static int 548237fead6SMichael Halcrow ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 549237fead6SMichael Halcrow { 550237fead6SMichael Halcrow int rc; 551237fead6SMichael Halcrow struct dentry *lower_dentry; 552237fead6SMichael Halcrow struct dentry *lower_dir_dentry; 553237fead6SMichael Halcrow 554237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 555237fead6SMichael Halcrow lower_dir_dentry = lock_parent(lower_dentry); 556237fead6SMichael Halcrow rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev); 557237fead6SMichael Halcrow if (rc || !lower_dentry->d_inode) 558237fead6SMichael Halcrow goto out; 559237fead6SMichael Halcrow rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); 560237fead6SMichael Halcrow if (rc) 561237fead6SMichael Halcrow goto out; 5620cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); 5630cc72dc7SJosef "Jeff" Sipek fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode); 564237fead6SMichael Halcrow out: 565237fead6SMichael Halcrow unlock_dir(lower_dir_dentry); 566237fead6SMichael Halcrow if (!dentry->d_inode) 567237fead6SMichael Halcrow d_drop(dentry); 568237fead6SMichael Halcrow return rc; 569237fead6SMichael Halcrow } 570237fead6SMichael Halcrow 571237fead6SMichael Halcrow static int 572237fead6SMichael Halcrow ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry, 573237fead6SMichael Halcrow struct inode *new_dir, struct dentry *new_dentry) 574237fead6SMichael Halcrow { 575237fead6SMichael Halcrow int rc; 576237fead6SMichael Halcrow struct dentry *lower_old_dentry; 577237fead6SMichael Halcrow struct dentry *lower_new_dentry; 578237fead6SMichael Halcrow struct dentry *lower_old_dir_dentry; 579237fead6SMichael Halcrow struct dentry *lower_new_dir_dentry; 580237fead6SMichael Halcrow 581237fead6SMichael Halcrow lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry); 582237fead6SMichael Halcrow lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry); 583237fead6SMichael Halcrow dget(lower_old_dentry); 584237fead6SMichael Halcrow dget(lower_new_dentry); 585237fead6SMichael Halcrow lower_old_dir_dentry = dget_parent(lower_old_dentry); 586237fead6SMichael Halcrow lower_new_dir_dentry = dget_parent(lower_new_dentry); 587237fead6SMichael Halcrow lock_rename(lower_old_dir_dentry, lower_new_dir_dentry); 588237fead6SMichael Halcrow rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry, 589237fead6SMichael Halcrow lower_new_dir_dentry->d_inode, lower_new_dentry); 590237fead6SMichael Halcrow if (rc) 591237fead6SMichael Halcrow goto out_lock; 5920cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode, NULL); 593237fead6SMichael Halcrow if (new_dir != old_dir) 5940cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode, NULL); 595237fead6SMichael Halcrow out_lock: 596237fead6SMichael Halcrow unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry); 597a9083081SMichael Halcrow dput(lower_new_dentry->d_parent); 598a9083081SMichael Halcrow dput(lower_old_dentry->d_parent); 599237fead6SMichael Halcrow dput(lower_new_dentry); 600237fead6SMichael Halcrow dput(lower_old_dentry); 601237fead6SMichael Halcrow return rc; 602237fead6SMichael Halcrow } 603237fead6SMichael Halcrow 604237fead6SMichael Halcrow static int 605237fead6SMichael Halcrow ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz) 606237fead6SMichael Halcrow { 607237fead6SMichael Halcrow int rc; 608237fead6SMichael Halcrow struct dentry *lower_dentry; 609237fead6SMichael Halcrow char *decoded_name; 610237fead6SMichael Halcrow char *lower_buf; 611237fead6SMichael Halcrow mm_segment_t old_fs; 612237fead6SMichael Halcrow struct ecryptfs_crypt_stat *crypt_stat; 613237fead6SMichael Halcrow 614237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 615237fead6SMichael Halcrow if (!lower_dentry->d_inode->i_op || 616237fead6SMichael Halcrow !lower_dentry->d_inode->i_op->readlink) { 617237fead6SMichael Halcrow rc = -EINVAL; 618237fead6SMichael Halcrow goto out; 619237fead6SMichael Halcrow } 620237fead6SMichael Halcrow /* Released in this function */ 621237fead6SMichael Halcrow lower_buf = kmalloc(bufsiz, GFP_KERNEL); 622237fead6SMichael Halcrow if (lower_buf == NULL) { 623237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, "Out of memory\n"); 624237fead6SMichael Halcrow rc = -ENOMEM; 625237fead6SMichael Halcrow goto out; 626237fead6SMichael Halcrow } 627237fead6SMichael Halcrow old_fs = get_fs(); 628237fead6SMichael Halcrow set_fs(get_ds()); 629237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ " 630237fead6SMichael Halcrow "lower_dentry->d_name.name = [%s]\n", 631237fead6SMichael Halcrow lower_dentry->d_name.name); 632237fead6SMichael Halcrow rc = lower_dentry->d_inode->i_op->readlink(lower_dentry, 633237fead6SMichael Halcrow (char __user *)lower_buf, 634237fead6SMichael Halcrow bufsiz); 635237fead6SMichael Halcrow set_fs(old_fs); 636237fead6SMichael Halcrow if (rc >= 0) { 637237fead6SMichael Halcrow crypt_stat = NULL; 638237fead6SMichael Halcrow rc = ecryptfs_decode_filename(crypt_stat, lower_buf, rc, 639237fead6SMichael Halcrow &decoded_name); 640237fead6SMichael Halcrow if (rc == -ENOMEM) 641237fead6SMichael Halcrow goto out_free_lower_buf; 642237fead6SMichael Halcrow if (rc > 0) { 643237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "Copying [%d] bytes " 644237fead6SMichael Halcrow "to userspace: [%*s]\n", rc, 645237fead6SMichael Halcrow decoded_name); 646237fead6SMichael Halcrow if (copy_to_user(buf, decoded_name, rc)) 647237fead6SMichael Halcrow rc = -EFAULT; 648237fead6SMichael Halcrow } 649237fead6SMichael Halcrow kfree(decoded_name); 6500cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_atime(dentry->d_inode, 651237fead6SMichael Halcrow lower_dentry->d_inode); 652237fead6SMichael Halcrow } 653237fead6SMichael Halcrow out_free_lower_buf: 654237fead6SMichael Halcrow kfree(lower_buf); 655237fead6SMichael Halcrow out: 656237fead6SMichael Halcrow return rc; 657237fead6SMichael Halcrow } 658237fead6SMichael Halcrow 659237fead6SMichael Halcrow static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd) 660237fead6SMichael Halcrow { 661237fead6SMichael Halcrow char *buf; 662237fead6SMichael Halcrow int len = PAGE_SIZE, rc; 663237fead6SMichael Halcrow mm_segment_t old_fs; 664237fead6SMichael Halcrow 665237fead6SMichael Halcrow /* Released in ecryptfs_put_link(); only release here on error */ 666237fead6SMichael Halcrow buf = kmalloc(len, GFP_KERNEL); 667237fead6SMichael Halcrow if (!buf) { 668237fead6SMichael Halcrow rc = -ENOMEM; 669237fead6SMichael Halcrow goto out; 670237fead6SMichael Halcrow } 671237fead6SMichael Halcrow old_fs = get_fs(); 672237fead6SMichael Halcrow set_fs(get_ds()); 673237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ " 674237fead6SMichael Halcrow "dentry->d_name.name = [%s]\n", dentry->d_name.name); 675237fead6SMichael Halcrow rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len); 676237fead6SMichael Halcrow buf[rc] = '\0'; 677237fead6SMichael Halcrow set_fs(old_fs); 678237fead6SMichael Halcrow if (rc < 0) 679237fead6SMichael Halcrow goto out_free; 680237fead6SMichael Halcrow rc = 0; 681237fead6SMichael Halcrow nd_set_link(nd, buf); 682237fead6SMichael Halcrow goto out; 683237fead6SMichael Halcrow out_free: 684237fead6SMichael Halcrow kfree(buf); 685237fead6SMichael Halcrow out: 686237fead6SMichael Halcrow return ERR_PTR(rc); 687237fead6SMichael Halcrow } 688237fead6SMichael Halcrow 689237fead6SMichael Halcrow static void 690237fead6SMichael Halcrow ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr) 691237fead6SMichael Halcrow { 692237fead6SMichael Halcrow /* Free the char* */ 693237fead6SMichael Halcrow kfree(nd_get_link(nd)); 694237fead6SMichael Halcrow } 695237fead6SMichael Halcrow 696237fead6SMichael Halcrow /** 697237fead6SMichael Halcrow * upper_size_to_lower_size 698237fead6SMichael Halcrow * @crypt_stat: Crypt_stat associated with file 699237fead6SMichael Halcrow * @upper_size: Size of the upper file 700237fead6SMichael Halcrow * 701237fead6SMichael Halcrow * Calculate the requried size of the lower file based on the 702237fead6SMichael Halcrow * specified size of the upper file. This calculation is based on the 703237fead6SMichael Halcrow * number of headers in the underlying file and the extent size. 704237fead6SMichael Halcrow * 705237fead6SMichael Halcrow * Returns Calculated size of the lower file. 706237fead6SMichael Halcrow */ 707237fead6SMichael Halcrow static loff_t 708237fead6SMichael Halcrow upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat, 709237fead6SMichael Halcrow loff_t upper_size) 710237fead6SMichael Halcrow { 711237fead6SMichael Halcrow loff_t lower_size; 712237fead6SMichael Halcrow 713237fead6SMichael Halcrow lower_size = ( crypt_stat->header_extent_size 714237fead6SMichael Halcrow * crypt_stat->num_header_extents_at_front ); 715237fead6SMichael Halcrow if (upper_size != 0) { 716237fead6SMichael Halcrow loff_t num_extents; 717237fead6SMichael Halcrow 718237fead6SMichael Halcrow num_extents = upper_size >> crypt_stat->extent_shift; 719237fead6SMichael Halcrow if (upper_size & ~crypt_stat->extent_mask) 720237fead6SMichael Halcrow num_extents++; 721237fead6SMichael Halcrow lower_size += (num_extents * crypt_stat->extent_size); 722237fead6SMichael Halcrow } 723237fead6SMichael Halcrow return lower_size; 724237fead6SMichael Halcrow } 725237fead6SMichael Halcrow 726237fead6SMichael Halcrow /** 727237fead6SMichael Halcrow * ecryptfs_truncate 728237fead6SMichael Halcrow * @dentry: The ecryptfs layer dentry 729237fead6SMichael Halcrow * @new_length: The length to expand the file to 730237fead6SMichael Halcrow * 731237fead6SMichael Halcrow * Function to handle truncations modifying the size of the file. Note 732237fead6SMichael Halcrow * that the file sizes are interpolated. When expanding, we are simply 733237fead6SMichael Halcrow * writing strings of 0's out. When truncating, we need to modify the 734237fead6SMichael Halcrow * underlying file size according to the page index interpolations. 735237fead6SMichael Halcrow * 736237fead6SMichael Halcrow * Returns zero on success; non-zero otherwise 737237fead6SMichael Halcrow */ 738237fead6SMichael Halcrow int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) 739237fead6SMichael Halcrow { 740237fead6SMichael Halcrow int rc = 0; 741237fead6SMichael Halcrow struct inode *inode = dentry->d_inode; 742237fead6SMichael Halcrow struct dentry *lower_dentry; 743237fead6SMichael Halcrow struct vfsmount *lower_mnt; 744237fead6SMichael Halcrow struct file fake_ecryptfs_file, *lower_file = NULL; 745237fead6SMichael Halcrow struct ecryptfs_crypt_stat *crypt_stat; 746237fead6SMichael Halcrow loff_t i_size = i_size_read(inode); 747237fead6SMichael Halcrow loff_t lower_size_before_truncate; 748237fead6SMichael Halcrow loff_t lower_size_after_truncate; 749237fead6SMichael Halcrow 750237fead6SMichael Halcrow if (unlikely((new_length == i_size))) 751237fead6SMichael Halcrow goto out; 752237fead6SMichael Halcrow crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; 753237fead6SMichael Halcrow /* Set up a fake ecryptfs file, this is used to interface with 754237fead6SMichael Halcrow * the file in the underlying filesystem so that the 755237fead6SMichael Halcrow * truncation has an effect there as well. */ 756237fead6SMichael Halcrow memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file)); 757bd243a4bSJosef "Jeff" Sipek fake_ecryptfs_file.f_path.dentry = dentry; 758237fead6SMichael Halcrow /* Released at out_free: label */ 759237fead6SMichael Halcrow ecryptfs_set_file_private(&fake_ecryptfs_file, 760237fead6SMichael Halcrow kmem_cache_alloc(ecryptfs_file_info_cache, 761e94b1766SChristoph Lameter GFP_KERNEL)); 762237fead6SMichael Halcrow if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) { 763237fead6SMichael Halcrow rc = -ENOMEM; 764237fead6SMichael Halcrow goto out; 765237fead6SMichael Halcrow } 766237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 767237fead6SMichael Halcrow /* This dget & mntget is released through fput at out_fput: */ 768237fead6SMichael Halcrow lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); 7697ff1d74fSMichael Halcrow if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt, 7707ff1d74fSMichael Halcrow O_RDWR))) { 7717ff1d74fSMichael Halcrow ecryptfs_printk(KERN_ERR, 7727ff1d74fSMichael Halcrow "Error opening dentry; rc = [%i]\n", rc); 773237fead6SMichael Halcrow goto out_free; 774237fead6SMichael Halcrow } 775237fead6SMichael Halcrow ecryptfs_set_file_lower(&fake_ecryptfs_file, lower_file); 776237fead6SMichael Halcrow /* Switch on growing or shrinking file */ 777237fead6SMichael Halcrow if (new_length > i_size) { 778237fead6SMichael Halcrow rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length); 779237fead6SMichael Halcrow if (rc) { 780237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, 781237fead6SMichael Halcrow "Problem with fill_zeros\n"); 782237fead6SMichael Halcrow goto out_fput; 783237fead6SMichael Halcrow } 784237fead6SMichael Halcrow i_size_write(inode, new_length); 785237fead6SMichael Halcrow rc = ecryptfs_write_inode_size_to_header(lower_file, 786237fead6SMichael Halcrow lower_dentry->d_inode, 787237fead6SMichael Halcrow inode); 788237fead6SMichael Halcrow if (rc) { 789237fead6SMichael Halcrow ecryptfs_printk(KERN_ERR, 790237fead6SMichael Halcrow "Problem with ecryptfs_write" 791237fead6SMichael Halcrow "_inode_size\n"); 792237fead6SMichael Halcrow goto out_fput; 793237fead6SMichael Halcrow } 794237fead6SMichael Halcrow } else { /* new_length < i_size_read(inode) */ 795237fead6SMichael Halcrow vmtruncate(inode, new_length); 796237fead6SMichael Halcrow ecryptfs_write_inode_size_to_header(lower_file, 797237fead6SMichael Halcrow lower_dentry->d_inode, 798237fead6SMichael Halcrow inode); 799237fead6SMichael Halcrow /* We are reducing the size of the ecryptfs file, and need to 800237fead6SMichael Halcrow * know if we need to reduce the size of the lower file. */ 801237fead6SMichael Halcrow lower_size_before_truncate = 802237fead6SMichael Halcrow upper_size_to_lower_size(crypt_stat, i_size); 803237fead6SMichael Halcrow lower_size_after_truncate = 804237fead6SMichael Halcrow upper_size_to_lower_size(crypt_stat, new_length); 805237fead6SMichael Halcrow if (lower_size_after_truncate < lower_size_before_truncate) 806237fead6SMichael Halcrow vmtruncate(lower_dentry->d_inode, 807237fead6SMichael Halcrow lower_size_after_truncate); 808237fead6SMichael Halcrow } 809237fead6SMichael Halcrow /* Update the access times */ 810237fead6SMichael Halcrow lower_dentry->d_inode->i_mtime = lower_dentry->d_inode->i_ctime 811237fead6SMichael Halcrow = CURRENT_TIME; 812237fead6SMichael Halcrow mark_inode_dirty_sync(inode); 813237fead6SMichael Halcrow out_fput: 8147ff1d74fSMichael Halcrow if ((rc = ecryptfs_close_lower_file(lower_file))) 8157ff1d74fSMichael Halcrow printk(KERN_ERR "Error closing lower_file\n"); 816237fead6SMichael Halcrow out_free: 817237fead6SMichael Halcrow if (ecryptfs_file_to_private(&fake_ecryptfs_file)) 818237fead6SMichael Halcrow kmem_cache_free(ecryptfs_file_info_cache, 819237fead6SMichael Halcrow ecryptfs_file_to_private(&fake_ecryptfs_file)); 820237fead6SMichael Halcrow out: 821237fead6SMichael Halcrow return rc; 822237fead6SMichael Halcrow } 823237fead6SMichael Halcrow 824237fead6SMichael Halcrow static int 825237fead6SMichael Halcrow ecryptfs_permission(struct inode *inode, int mask, struct nameidata *nd) 826237fead6SMichael Halcrow { 827237fead6SMichael Halcrow int rc; 828237fead6SMichael Halcrow 829237fead6SMichael Halcrow if (nd) { 830237fead6SMichael Halcrow struct vfsmount *vfsmnt_save = nd->mnt; 831237fead6SMichael Halcrow struct dentry *dentry_save = nd->dentry; 832237fead6SMichael Halcrow 833237fead6SMichael Halcrow nd->mnt = ecryptfs_dentry_to_lower_mnt(nd->dentry); 834237fead6SMichael Halcrow nd->dentry = ecryptfs_dentry_to_lower(nd->dentry); 835237fead6SMichael Halcrow rc = permission(ecryptfs_inode_to_lower(inode), mask, nd); 836237fead6SMichael Halcrow nd->mnt = vfsmnt_save; 837237fead6SMichael Halcrow nd->dentry = dentry_save; 838237fead6SMichael Halcrow } else 839237fead6SMichael Halcrow rc = permission(ecryptfs_inode_to_lower(inode), mask, NULL); 840237fead6SMichael Halcrow return rc; 841237fead6SMichael Halcrow } 842237fead6SMichael Halcrow 843237fead6SMichael Halcrow /** 844237fead6SMichael Halcrow * ecryptfs_setattr 845237fead6SMichael Halcrow * @dentry: dentry handle to the inode to modify 846237fead6SMichael Halcrow * @ia: Structure with flags of what to change and values 847237fead6SMichael Halcrow * 848237fead6SMichael Halcrow * Updates the metadata of an inode. If the update is to the size 849237fead6SMichael Halcrow * i.e. truncation, then ecryptfs_truncate will handle the size modification 850237fead6SMichael Halcrow * of both the ecryptfs inode and the lower inode. 851237fead6SMichael Halcrow * 852237fead6SMichael Halcrow * All other metadata changes will be passed right to the lower filesystem, 853237fead6SMichael Halcrow * and we will just update our inode to look like the lower. 854237fead6SMichael Halcrow */ 855237fead6SMichael Halcrow static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) 856237fead6SMichael Halcrow { 857237fead6SMichael Halcrow int rc = 0; 858237fead6SMichael Halcrow struct dentry *lower_dentry; 859237fead6SMichael Halcrow struct inode *inode; 860237fead6SMichael Halcrow struct inode *lower_inode; 861237fead6SMichael Halcrow struct ecryptfs_crypt_stat *crypt_stat; 862237fead6SMichael Halcrow 863237fead6SMichael Halcrow crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; 864237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 865237fead6SMichael Halcrow inode = dentry->d_inode; 866237fead6SMichael Halcrow lower_inode = ecryptfs_inode_to_lower(inode); 867237fead6SMichael Halcrow if (ia->ia_valid & ATTR_SIZE) { 868237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, 869237fead6SMichael Halcrow "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n", 870237fead6SMichael Halcrow ia->ia_valid, ATTR_SIZE); 871237fead6SMichael Halcrow rc = ecryptfs_truncate(dentry, ia->ia_size); 872237fead6SMichael Halcrow /* ecryptfs_truncate handles resizing of the lower file */ 873237fead6SMichael Halcrow ia->ia_valid &= ~ATTR_SIZE; 874237fead6SMichael Halcrow ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n", 875237fead6SMichael Halcrow ia->ia_valid); 876237fead6SMichael Halcrow if (rc < 0) 877237fead6SMichael Halcrow goto out; 878237fead6SMichael Halcrow } 879237fead6SMichael Halcrow rc = notify_change(lower_dentry, ia); 880237fead6SMichael Halcrow out: 8810cc72dc7SJosef "Jeff" Sipek fsstack_copy_attr_all(inode, lower_inode, NULL); 882237fead6SMichael Halcrow return rc; 883237fead6SMichael Halcrow } 884237fead6SMichael Halcrow 885237fead6SMichael Halcrow static int 886237fead6SMichael Halcrow ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value, 887237fead6SMichael Halcrow size_t size, int flags) 888237fead6SMichael Halcrow { 889237fead6SMichael Halcrow int rc = 0; 890237fead6SMichael Halcrow struct dentry *lower_dentry; 891237fead6SMichael Halcrow 892237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 893237fead6SMichael Halcrow if (!lower_dentry->d_inode->i_op->setxattr) { 894237fead6SMichael Halcrow rc = -ENOSYS; 895237fead6SMichael Halcrow goto out; 896237fead6SMichael Halcrow } 897237fead6SMichael Halcrow mutex_lock(&lower_dentry->d_inode->i_mutex); 898237fead6SMichael Halcrow rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value, 899237fead6SMichael Halcrow size, flags); 900237fead6SMichael Halcrow mutex_unlock(&lower_dentry->d_inode->i_mutex); 901237fead6SMichael Halcrow out: 902237fead6SMichael Halcrow return rc; 903237fead6SMichael Halcrow } 904237fead6SMichael Halcrow 905237fead6SMichael Halcrow static ssize_t 906237fead6SMichael Halcrow ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value, 907237fead6SMichael Halcrow size_t size) 908237fead6SMichael Halcrow { 909237fead6SMichael Halcrow int rc = 0; 910237fead6SMichael Halcrow struct dentry *lower_dentry; 911237fead6SMichael Halcrow 912237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 913237fead6SMichael Halcrow if (!lower_dentry->d_inode->i_op->getxattr) { 914237fead6SMichael Halcrow rc = -ENOSYS; 915237fead6SMichael Halcrow goto out; 916237fead6SMichael Halcrow } 917237fead6SMichael Halcrow mutex_lock(&lower_dentry->d_inode->i_mutex); 918237fead6SMichael Halcrow rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value, 919237fead6SMichael Halcrow size); 920237fead6SMichael Halcrow mutex_unlock(&lower_dentry->d_inode->i_mutex); 921237fead6SMichael Halcrow out: 922237fead6SMichael Halcrow return rc; 923237fead6SMichael Halcrow } 924237fead6SMichael Halcrow 925237fead6SMichael Halcrow static ssize_t 926237fead6SMichael Halcrow ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size) 927237fead6SMichael Halcrow { 928237fead6SMichael Halcrow int rc = 0; 929237fead6SMichael Halcrow struct dentry *lower_dentry; 930237fead6SMichael Halcrow 931237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 932237fead6SMichael Halcrow if (!lower_dentry->d_inode->i_op->listxattr) { 933237fead6SMichael Halcrow rc = -ENOSYS; 934237fead6SMichael Halcrow goto out; 935237fead6SMichael Halcrow } 936237fead6SMichael Halcrow mutex_lock(&lower_dentry->d_inode->i_mutex); 937237fead6SMichael Halcrow rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size); 938237fead6SMichael Halcrow mutex_unlock(&lower_dentry->d_inode->i_mutex); 939237fead6SMichael Halcrow out: 940237fead6SMichael Halcrow return rc; 941237fead6SMichael Halcrow } 942237fead6SMichael Halcrow 943237fead6SMichael Halcrow static int ecryptfs_removexattr(struct dentry *dentry, const char *name) 944237fead6SMichael Halcrow { 945237fead6SMichael Halcrow int rc = 0; 946237fead6SMichael Halcrow struct dentry *lower_dentry; 947237fead6SMichael Halcrow 948237fead6SMichael Halcrow lower_dentry = ecryptfs_dentry_to_lower(dentry); 949237fead6SMichael Halcrow if (!lower_dentry->d_inode->i_op->removexattr) { 950237fead6SMichael Halcrow rc = -ENOSYS; 951237fead6SMichael Halcrow goto out; 952237fead6SMichael Halcrow } 953237fead6SMichael Halcrow mutex_lock(&lower_dentry->d_inode->i_mutex); 954237fead6SMichael Halcrow rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name); 955237fead6SMichael Halcrow mutex_unlock(&lower_dentry->d_inode->i_mutex); 956237fead6SMichael Halcrow out: 957237fead6SMichael Halcrow return rc; 958237fead6SMichael Halcrow } 959237fead6SMichael Halcrow 960237fead6SMichael Halcrow int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode) 961237fead6SMichael Halcrow { 962237fead6SMichael Halcrow if ((ecryptfs_inode_to_lower(inode) 963237fead6SMichael Halcrow == (struct inode *)candidate_lower_inode)) 964237fead6SMichael Halcrow return 1; 965237fead6SMichael Halcrow else 966237fead6SMichael Halcrow return 0; 967237fead6SMichael Halcrow } 968237fead6SMichael Halcrow 969237fead6SMichael Halcrow int ecryptfs_inode_set(struct inode *inode, void *lower_inode) 970237fead6SMichael Halcrow { 971237fead6SMichael Halcrow ecryptfs_init_inode(inode, (struct inode *)lower_inode); 972237fead6SMichael Halcrow return 0; 973237fead6SMichael Halcrow } 974237fead6SMichael Halcrow 975237fead6SMichael Halcrow struct inode_operations ecryptfs_symlink_iops = { 976237fead6SMichael Halcrow .readlink = ecryptfs_readlink, 977237fead6SMichael Halcrow .follow_link = ecryptfs_follow_link, 978237fead6SMichael Halcrow .put_link = ecryptfs_put_link, 979237fead6SMichael Halcrow .permission = ecryptfs_permission, 980237fead6SMichael Halcrow .setattr = ecryptfs_setattr, 981237fead6SMichael Halcrow .setxattr = ecryptfs_setxattr, 982237fead6SMichael Halcrow .getxattr = ecryptfs_getxattr, 983237fead6SMichael Halcrow .listxattr = ecryptfs_listxattr, 984237fead6SMichael Halcrow .removexattr = ecryptfs_removexattr 985237fead6SMichael Halcrow }; 986237fead6SMichael Halcrow 987237fead6SMichael Halcrow struct inode_operations ecryptfs_dir_iops = { 988237fead6SMichael Halcrow .create = ecryptfs_create, 989237fead6SMichael Halcrow .lookup = ecryptfs_lookup, 990237fead6SMichael Halcrow .link = ecryptfs_link, 991237fead6SMichael Halcrow .unlink = ecryptfs_unlink, 992237fead6SMichael Halcrow .symlink = ecryptfs_symlink, 993237fead6SMichael Halcrow .mkdir = ecryptfs_mkdir, 994237fead6SMichael Halcrow .rmdir = ecryptfs_rmdir, 995237fead6SMichael Halcrow .mknod = ecryptfs_mknod, 996237fead6SMichael Halcrow .rename = ecryptfs_rename, 997237fead6SMichael Halcrow .permission = ecryptfs_permission, 998237fead6SMichael Halcrow .setattr = ecryptfs_setattr, 999237fead6SMichael Halcrow .setxattr = ecryptfs_setxattr, 1000237fead6SMichael Halcrow .getxattr = ecryptfs_getxattr, 1001237fead6SMichael Halcrow .listxattr = ecryptfs_listxattr, 1002237fead6SMichael Halcrow .removexattr = ecryptfs_removexattr 1003237fead6SMichael Halcrow }; 1004237fead6SMichael Halcrow 1005237fead6SMichael Halcrow struct inode_operations ecryptfs_main_iops = { 1006237fead6SMichael Halcrow .permission = ecryptfs_permission, 1007237fead6SMichael Halcrow .setattr = ecryptfs_setattr, 1008237fead6SMichael Halcrow .setxattr = ecryptfs_setxattr, 1009237fead6SMichael Halcrow .getxattr = ecryptfs_getxattr, 1010237fead6SMichael Halcrow .listxattr = ecryptfs_listxattr, 1011237fead6SMichael Halcrow .removexattr = ecryptfs_removexattr 1012237fead6SMichael Halcrow }; 1013