Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751351AbVKSEVi (ORCPT ); Fri, 18 Nov 2005 23:21:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751347AbVKSEVh (ORCPT ); Fri, 18 Nov 2005 23:21:37 -0500 Received: from c-67-182-200-232.hsd1.ut.comcast.net ([67.182.200.232]:17654 "EHLO sshock.homelinux.net") by vger.kernel.org with ESMTP id S1751320AbVKSEVf (ORCPT ); Fri, 18 Nov 2005 23:21:35 -0500 Date: Fri, 18 Nov 2005 21:21:30 -0700 From: Phillip Hellewell To: akpm@osdl.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, viro@ftp.linux.org.uk, mike@halcrow.us, mhalcrow@us.ibm.com, mcthomps@us.ibm.com, yoder1@us.ibm.com Subject: [PATCH 9/12: eCryptfs] Inode operations Message-ID: <20051119042130.GI15747@sshock.rn.byu.edu> References: <20051119041130.GA15559@sshock.rn.byu.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051119041130.GA15559@sshock.rn.byu.edu> X-URL: http://hellewell.homeip.net/ User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 35553 Lines: 1103 eCryptfs inode operations. Includes functions to support inode interpolation between upper and lower inodes. Signed-off-by: Phillip Hellewell Signed-off-by: Michael Halcrow Signed-off-by: Michael Thompson --- inode.c | 1084 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 1084 insertions(+) --- linux-2.6.15-rc1-mm1/fs/ecryptfs/inode.c 1969-12-31 18:00:00.000000000 -0600 +++ linux-2.6.15-rc1-mm1-ecryptfs/fs/ecryptfs/inode.c 2005-11-18 11:20:09.000000000 -0600 @@ -0,0 +1,1084 @@ +/** + * eCryptfs: Linux filesystem encryption layer + * + * Copyright (c) 1997-2004 Erez Zadok + * Copyright (c) 2001-2004 Stony Brook University + * Copyright (c) 2005 International Business Machines Corp. + * Author(s): Michael A. Halcrow + * Michael C. Thompsion + * + * 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 +#include +#include +#include +#include +#include +#include +#include "ecryptfs_kernel.h" + +static inline struct dentry *lock_parent(struct dentry *dentry) +{ + struct dentry *dir; + + dir = dget(dentry->d_parent); + down(&(dir->d_inode->i_sem)); + return dir; +} + +static inline void unlock_parent(struct dentry *dentry) +{ + up(&(dentry->d_parent->d_inode->i_sem)); + dput(dentry->d_parent); +} + +static inline void unlock_dir(struct dentry *dir) +{ + up(&dir->d_inode->i_sem); + dput(dir); +} + +void ecryptfs_copy_inode_size(struct inode *dst, const struct inode *src) +{ + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + ecryptfs_printk(1, KERN_NOTICE, "src->i_size = [%lld]\n", src->i_size); + ecryptfs_printk(1, KERN_NOTICE, "src->i_blocks = [%lu]\n", + src->i_blocks); + i_size_write(dst, i_size_read((struct inode *)src)); + dst->i_blocks = src->i_blocks; + ecryptfs_printk(1, KERN_NOTICE, "Exit\n"); +} + +void ecryptfs_copy_attr_atime(struct inode *dest, const struct inode *src) +{ + ASSERT(dest != NULL); + ASSERT(src != NULL); + dest->i_atime = src->i_atime; +} + +void ecryptfs_copy_attr_times(struct inode *dest, const struct inode *src) +{ + ASSERT(dest != NULL); + ASSERT(src != NULL); + dest->i_atime = src->i_atime; + dest->i_mtime = src->i_mtime; + dest->i_ctime = src->i_ctime; +} + +static void ecryptfs_copy_attr_timesizes(struct inode *dest, + const struct inode *src) +{ + ASSERT(dest != NULL); + ASSERT(src != NULL); + dest->i_atime = src->i_atime; + dest->i_mtime = src->i_mtime; + dest->i_ctime = src->i_ctime; + ecryptfs_copy_inode_size(dest, src); +} + +void ecryptfs_copy_attr_all(struct inode *dest, const struct inode *src) +{ + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + ASSERT(dest != NULL); + ASSERT(src != NULL); + dest->i_mode = src->i_mode; + dest->i_nlink = src->i_nlink; + dest->i_uid = src->i_uid; + dest->i_gid = src->i_gid; + dest->i_rdev = src->i_rdev; + dest->i_atime = src->i_atime; + dest->i_mtime = src->i_mtime; + dest->i_ctime = src->i_ctime; + dest->i_blksize = src->i_blksize; + ecryptfs_printk(1, KERN_NOTICE, "src->i_blksize = [%lu]\n", + src->i_blksize); + dest->i_blkbits = src->i_blkbits; + dest->i_flags = src->i_flags; + ecryptfs_printk(1, KERN_NOTICE, "Exit\n"); +} + +/** + * Creates our file in the lower file system + * + * @param lower_dir_inode inode of the parent in the lower fs of the new file + * @param lower_dentry New file's dentry in the lower fs + * @param ecryptfs_dentry New file's dentry in ecryptfs + * @param mode The mode of the new file + * @param nd nameidata of ecryptfs' parent's dentry & vfsmnt + * @return 0 on success; non-zero on error condition + */ +static int +ecryptfs_create_underlying_file(struct inode *lower_dir_inode, + struct dentry *lower_dentry, + struct dentry *ecryptfs_dentry, int mode, + struct nameidata *nd) +{ + int rc; + struct dentry *saved_dentry = NULL; + struct vfsmount *saved_vfsmount = NULL; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + saved_dentry = nd->dentry; + saved_vfsmount = nd->mnt; + nd->dentry = lower_dentry; + nd->mnt = ECRYPTFS_SUPERBLOCK_TO_PRIVATE( + ecryptfs_dentry->d_sb)->lower_mnt; + rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd); + nd->dentry = saved_dentry; + nd->mnt = saved_vfsmount; + ecryptfs_printk(1, KERN_NOTICE, "Exit; rc = [%d]\n", rc); + return rc; +} + +/** + * Creates the underlying file and the eCryptfs inode which will link to + * it. It will also update the eCryptfs directory inode to mimic the + * stats of the lower directory inode + * + * @param directory_inode inode of the new file's dentry's parent in ecryptfs + * @param ecryptfs_dentry New file's dentry in ecryptfs + * @param mode The mode of the new file + * @param nd nameidata of ecryptfs' parent's dentry & vfsmnt + * @return 0 on success; non-zero on error condition + */ +static int +ecryptfs_do_create(struct inode *directory_inode, + struct dentry *ecryptfs_dentry, int mode, + struct nameidata *nd) +{ + int rc; + struct dentry *lower_dentry; + struct dentry *lower_dir_dentry; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + lower_dentry = ecryptfs_lower_dentry(ecryptfs_dentry); + if (IS_ERR(lower_dentry)) { + ecryptfs_printk(0, KERN_ERR, "ecryptfs dentry doesn't know" + "about its lower counterpart\n"); + rc = PTR_ERR(lower_dentry); + goto out; + } + lower_dir_dentry = lock_parent(lower_dentry); + if (unlikely(IS_ERR(lower_dir_dentry))) { + ecryptfs_printk(0, KERN_ERR, "Error locking directory of " + "dentry\n"); + rc = PTR_ERR(lower_dir_dentry); + goto out; + } + rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode, + lower_dentry, ecryptfs_dentry, + mode, nd); + if (unlikely(rc)) { + ecryptfs_printk(0, KERN_ERR, + "Failure to create underlying file\n"); + goto out_lock; + } + rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry, + directory_inode->i_sb, 0); + if (rc) { + ecryptfs_printk(0, KERN_ERR, "Failure in ecryptfs_interpose\n"); + goto out_lock; + } + ecryptfs_copy_attr_timesizes(directory_inode, + lower_dir_dentry->d_inode); +out_lock: + unlock_dir(lower_dir_dentry); +out: + ecryptfs_printk(1, KERN_NOTICE, "Exit; rc = [%d]\n", rc); + return rc; +} + +/** + * This is the code which will grow the file to be 8192 or + * 12288, depending on whether the file derived-IV or + * written-IV formatted. + */ +static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file, + struct inode *inode, struct inode *lower_inode) +{ + int rc = 0; + struct file fake_file; + + memset(&fake_file, 0, sizeof(fake_file)); + fake_file.f_dentry = ecryptfs_dentry; + ECRYPTFS_FILE_TO_PRIVATE_SM(&fake_file) = + kmem_cache_alloc(ecryptfs_file_info_cache, SLAB_KERNEL); + if (!(ECRYPTFS_FILE_TO_PRIVATE_SM(&fake_file))) { + rc = -ENOMEM; + goto out; + } + ECRYPTFS_FILE_TO_LOWER(&fake_file) = lower_file; + ecryptfs_fill_zeros(&fake_file, 1); + kmem_cache_free(ecryptfs_file_info_cache, + ECRYPTFS_FILE_TO_PRIVATE(&fake_file)); + i_size_write(inode, 0); + ecryptfs_write_inode_size_to_header(lower_file, lower_inode, inode); + ECRYPTFS_INODE_TO_PRIVATE(inode)->crypt_stats.new_file = 1; +out: + return rc; +} + +/** + * Force the file to be changed from a basic empty file to an ecryptfs file + * with a header, 1st IV page & 1st data page + * + * @return Zero on success + */ +static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) +{ + int rc = 0; + int lower_flags; + struct ecryptfs_crypt_stats *crypt_stats; + struct dentry *lower_dentry; + struct dentry *tlower_dentry = NULL; + struct file *lower_file; + struct inode *inode, *lower_inode; + struct vfsmount *lower_mnt; + + ecryptfs_printk(1, KERN_NOTICE, "Enter; dentry->d_name.name = [%s]\n", + ecryptfs_dentry->d_name.name); + + lower_dentry = ecryptfs_lower_dentry(ecryptfs_dentry); + if (IS_ERR(lower_dentry)) { + ecryptfs_printk(0, KERN_ERR, "ecryptfs dentry doesn't know" + "about its lower counterpart\n"); + rc = PTR_ERR(lower_dentry); + goto out; + } + + ecryptfs_printk(1, KERN_NOTICE, "lower_dentry->d_name.name = [%s]\n", + lower_dentry->d_name.name); + + /* This code is migrated from ecryptfs_open... + * there is no reason that this shouldn't just "work" + * The flags and mode for the file passed into ecryptfs_open is: + * f->f_flags = flags; + * f->f_mode = ((flags+1) & O_ACCMODE) + * | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; + * + * Where flags = O_CREAT | O_WRONLY | O_TRUNC & + * ( #if BITS_PER_LONG != 32 ; flags |= O_LARGEFILE; #endif ) + * + * Code to initialize the file to be a valid ecryptfs file + */ + inode = ecryptfs_dentry->d_inode; + crypt_stats = &(ECRYPTFS_INODE_TO_PRIVATE(inode)->crypt_stats); + /* TODO: Initialization is done in alloc_inode, BUG if its not done */ + if (!crypt_stats->struct_initialized) + BUG(); + tlower_dentry = dget(lower_dentry); + if (!tlower_dentry) { + rc = -ENOMEM; + ecryptfs_printk(0, KERN_ERR, "Error dget'ing lower_dentry\n"); + goto out; + } + lower_flags = ((O_CREAT | O_WRONLY | O_TRUNC) & O_ACCMODE) | O_RDWR; +#if BITS_PER_LONG != 32 + lower_flags |= O_LARGEFILE; +#endif + lower_mnt = ECRYPTFS_SUPERBLOCK_TO_PRIVATE(inode->i_sb)->lower_mnt; + mntget(lower_mnt); + /* Corresponding fput() at end of func */ + lower_file = dentry_open(tlower_dentry, lower_mnt, lower_flags); + if (IS_ERR(lower_file)) { + rc = PTR_ERR(lower_file); + ecryptfs_printk(0, KERN_ERR, + "Error opening dentry; rc = [%i]\n", rc); + goto out; + } + /* fput(lower_file) should handle the puts if we do this */ + lower_file->f_dentry = tlower_dentry; + lower_file->f_vfsmnt = lower_mnt; + lower_inode = tlower_dentry->d_inode; + if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { + ecryptfs_printk(1, KERN_NOTICE, "This is a directory\n"); + crypt_stats->encrypted = 0; + goto out_fput; + } + crypt_stats->new_file = 1; + ecryptfs_printk(1, KERN_NOTICE, "Initializing crypto context\n"); + rc = ecryptfs_new_file_context(ecryptfs_dentry); /* crypto.c */ + if (rc) { + ecryptfs_printk(1, KERN_NOTICE, "Error creating new file " + "context\n"); + goto out_fput; + } + rc = ecryptfs_write_headers(ecryptfs_dentry, lower_file); + if (rc) { + ecryptfs_printk(1, KERN_NOTICE, "Error writing headers\n"); + goto out_fput; + } + rc = grow_file(ecryptfs_dentry, lower_file, inode, lower_inode); +out_fput: + fput(lower_file); +out: + ecryptfs_printk(1, KERN_NOTICE, "Exit; rc = [%d]\n", rc); + return rc; +} + +/** + * Creates a new file. + * + * @param dir The inode of the directory in which to create the file. + * @param dentry The eCryptfs dentry + * @param mode The mode of the new file. + * @param nd nameidata + * @return 0 on success; non-zero on error condition + */ +static int +ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry, + int mode, struct nameidata *nd) +{ + int rc; + + ecryptfs_printk(1, KERN_NOTICE, "Enter; ecryptfs_dentry->d_name.name = " + "[%s], directory_inode=[%p], ecryptfs_dentry->d_parent" + "->d_inode=[%p], nd->dentry=[%p], nd->last.name=[%s], " + "ecryptfs_dentry=[%p]\n", ecryptfs_dentry->d_name.name, + directory_inode, ecryptfs_dentry->d_parent->d_inode, + nd->dentry, nd->last.name, ecryptfs_dentry); + + rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd); + if (unlikely(rc)) { + ecryptfs_printk(0, KERN_WARNING, "Failed to create file in" + "lower filesystem\n"); + goto out; + } + /* At this point, a file exists on "disk", we need to make sure + * that this on disk file is prepared to be an ecryptfs file */ + rc = ecryptfs_initialize_file(ecryptfs_dentry); + out: + ecryptfs_printk(1, KERN_NOTICE, "Exit; rc = [%d]\n", rc); + return rc; +} + +/** + * Find a file on disk. If the file does not exist, then we'll add it to the + * dentry cache and continue on to read it from the disk. + * + * @param dir inode + * @param dentry dentry + * @param nd nameidata; may be NULL + */ +static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, + struct nameidata *nd) +{ + int err = 0; + struct dentry *lower_dir_dentry; + struct dentry *lower_dentry; + struct dentry *tlower_dentry = NULL; + char *encoded_name; + unsigned int encoded_namelen; + struct ecryptfs_crypt_stats *crypt_stats = NULL; + char *page_virt = NULL; + struct inode *lower_inode; + unsigned long long file_size; + + ecryptfs_printk(1, KERN_NOTICE, "Enter; dir = [%p], dentry->d_name.nam" + "e = [%s], nd = [%p]\n", dir, dentry->d_name.name, nd); + + lower_dir_dentry = ecryptfs_lower_dentry(dentry->d_parent); + dentry->d_op = &ecryptfs_dops; + + /* Sanity Check: Make sure we can operate on the file */ + if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, ".")) + || (dentry->d_name.len == 2 && !strcmp(dentry->d_name.name, ".."))) + goto out_drop; + + encoded_namelen = ecryptfs_encode_filename(dentry->d_name.name, + dentry->d_name.len, + &encoded_name, + ECRYPTFS_SKIP_DOTS, + crypt_stats); + if (encoded_namelen < 0) { + err = encoded_namelen; + goto out_drop; + } + /* TODO: pretty sure we need to do a dput(lower_dentry) to + * counter */ + ecryptfs_printk(1, KERN_NOTICE, "encoded_name = [%s]; encoded_namelen " + "= [%d]\n", encoded_name, encoded_namelen); + /* TODO: BUG: What to do on symlink to directory? */ + lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry, + encoded_namelen - 1); + kfree(encoded_name); + if (IS_ERR(lower_dentry)) { + ecryptfs_printk(0, KERN_ERR, "ERR from lower_dentry\n"); + err = PTR_ERR(lower_dentry); + goto out_drop; + } + ecryptfs_printk(1, KERN_NOTICE, "lower_dentry = [%p]; lower_dentry->" + "d_name.name = [%s]\n", lower_dentry, + lower_dentry->d_name.name); + lower_inode = lower_dentry->d_inode; + ecryptfs_copy_attr_atime(dir, lower_dir_dentry->d_inode); + + /* Sanity check */ + ASSERT(atomic_read(&lower_dentry->d_count)); + + /* Private allocation */ + ECRYPTFS_DENTRY_TO_PRIVATE_SM(dentry) = + kmem_cache_alloc(ecryptfs_dentry_info_cache, SLAB_KERNEL); + if (!ECRYPTFS_DENTRY_TO_PRIVATE_SM(dentry)) { + err = -ENOMEM; + ecryptfs_printk(0, KERN_ERR, "Out of memory whilst attempting " + "to allocate ecryptfs_dentry_info struct\n"); + goto out_dput; + } + + ECRYPTFS_DENTRY_TO_LOWER(dentry) = lower_dentry; + if (!lower_dentry->d_inode) { + /* We want to add because we couldn't find in lower */ + d_add(dentry, NULL); + goto out; + } + err = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 1); + if (err) { + ecryptfs_printk(0, KERN_ERR, "Error interposing\n"); + goto out_dput; + } + /* Do we want to just get a handle to the directory and its lower + * and not abort with puts? + */ + if (S_ISDIR(lower_inode->i_mode)) { + ecryptfs_printk(1, KERN_NOTICE, "Is a directory; returning\n"); + goto out; + } + if (S_ISLNK(lower_inode->i_mode)) { + ecryptfs_printk(1, KERN_NOTICE, "Is a symlink; returning\n"); + goto out; + } + /* We have a NULL dentry, can we just skip over the read here? */ + if (!nd) { + ecryptfs_printk(1, KERN_NOTICE, "We have a NULL nd, just leave" + "as we *think* we are about to unlink\n"); + goto out; + } + tlower_dentry = dget(lower_dentry); + if (!tlower_dentry || IS_ERR(tlower_dentry)) { + err = -ENOMEM; + ecryptfs_printk(0, KERN_ERR, "Cannot dget lower_dentry\n"); + goto out_dput; + } + /* Released in this function */ + page_virt = + (char *)kmem_cache_alloc(ecryptfs_header_cache_2, + SLAB_USER); + if (!page_virt) { + err = -ENOMEM; + ecryptfs_printk(0, KERN_ERR, + "Cannot ecryptfs_kmalloc a page\n"); + goto out_dput; + } + + /* Use the file's "header" to determine if its an ecryptfs file */ + err = ecryptfs_read_header_region(page_virt, tlower_dentry, nd); + /* Force default values if we haven't parsed the header */ + crypt_stats = + &(ECRYPTFS_INODE_TO_PRIVATE(dentry->d_inode)->crypt_stats); + if (!crypt_stats->policy_applied) + ecryptfs_set_default_sizes(crypt_stats); + + if (err) { + err = 0; + ecryptfs_printk(1, KERN_WARNING, "Error reading header region;" + " assuming unencrypted\n"); + } else { + if (!contains_ecryptfs_marker(page_virt + + ECRYPTFS_FILE_SIZE_BYTES)) { + ecryptfs_printk(0, KERN_WARNING, "Underlying file " + "lacks recognizable eCryptfs marker\n"); + } + memcpy(&file_size, page_virt, sizeof(file_size)); + dentry->d_inode->i_size = file_size; + } + kmem_cache_free(ecryptfs_header_cache_2, page_virt); + goto out; + +out_dput: + dput(lower_dentry); + if (tlower_dentry) + dput(tlower_dentry); +out_drop: + d_drop(dentry); +out: + ecryptfs_printk(1, KERN_NOTICE, "Exit; err = [%d]\n", err); + return ERR_PTR(err); +} + +static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry) +{ + int err; + struct dentry *lower_old_dentry; + struct dentry *lower_new_dentry; + struct dentry *lower_dir_dentry; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + lower_old_dentry = ecryptfs_lower_dentry(old_dentry); + lower_new_dentry = ecryptfs_lower_dentry(new_dentry); + dget(lower_old_dentry); + dget(lower_new_dentry); + lower_dir_dentry = lock_parent(lower_new_dentry); + err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode, + lower_new_dentry); + if (err || !lower_new_dentry->d_inode) + goto out_lock; + err = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0); + if (err) + goto out_lock; + ecryptfs_copy_attr_timesizes(dir, lower_new_dentry->d_inode); + old_dentry->d_inode->i_nlink = + ECRYPTFS_INODE_TO_LOWER(old_dentry->d_inode)->i_nlink; +out_lock: + unlock_dir(lower_dir_dentry); + dput(lower_new_dentry); + dput(lower_old_dentry); + if (!new_dentry->d_inode) + d_drop(new_dentry); + ecryptfs_printk(1, KERN_NOTICE, "Exit; err = [%d]\n", err); + return err; +} + +static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry) +{ + int rc = 0; + struct dentry *lower_dentry = ECRYPTFS_DENTRY_TO_LOWER(dentry); + struct inode *lower_dir_inode = ECRYPTFS_INODE_TO_LOWER(dir); + ecryptfs_printk(1, KERN_NOTICE, "Enter; dentry->d_name = [%s]\n", + dentry->d_name.name); + lock_parent(lower_dentry); + rc = vfs_unlink(lower_dir_inode, lower_dentry); + if (rc) { + ecryptfs_printk(1, KERN_ERR, "Error in vfs_unlink\n"); + goto out_unlock; + } + ecryptfs_copy_attr_times(dir, lower_dir_inode); + dentry->d_inode->i_nlink = + ECRYPTFS_INODE_TO_LOWER(dentry->d_inode)->i_nlink; + dentry->d_inode->i_ctime = dir->i_ctime; +out_unlock: + unlock_parent(lower_dentry); + ecryptfs_printk(1, KERN_NOTICE, "Exit; rc = [%d]",rc); + return rc; +} + +static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + int err; + struct dentry *lower_dentry; + struct dentry *lower_dir_dentry; + umode_t mode; + char *encoded_symname; + unsigned int encoded_symlen; + struct ecryptfs_crypt_stats *crypt_stats = NULL; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + lower_dentry = ecryptfs_lower_dentry(dentry); + dget(lower_dentry); + lower_dir_dentry = lock_parent(lower_dentry); + mode = S_IALLUGO; + encoded_symlen = ecryptfs_encode_filename(symname, strlen(symname), + &encoded_symname, + ECRYPTFS_DO_DOTS, + crypt_stats); + if (encoded_symlen < 0) { + err = encoded_symlen; + goto out_lock; + } + err = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry, + encoded_symname, mode); + kfree(encoded_symname); + if (err || !lower_dentry->d_inode) + goto out_lock; + err = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); + if (err) + goto out_lock; + ecryptfs_copy_attr_timesizes(dir, lower_dir_dentry->d_inode); +out_lock: + unlock_dir(lower_dir_dentry); + dput(lower_dentry); + if (!dentry->d_inode) + d_drop(dentry); + return err; +} + +static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) +{ + int err; + struct dentry *lower_dentry; + struct dentry *lower_dir_dentry; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + lower_dentry = ecryptfs_lower_dentry(dentry); + lower_dir_dentry = lock_parent(lower_dentry); + err = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode); + if (err || !lower_dentry->d_inode) + goto out; + err = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); + if (err) + goto out; + ecryptfs_copy_attr_timesizes(dir, lower_dir_dentry->d_inode); + dir->i_nlink = lower_dir_dentry->d_inode->i_nlink; +out: + unlock_dir(lower_dir_dentry); + if (!dentry->d_inode) + d_drop(dentry); + ecryptfs_printk(1, KERN_NOTICE, "Exit; err = [%d]\n", err); + return err; +} + +static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + int err = 0; + struct dentry *tdentry = NULL; + struct dentry *lower_dentry; + struct dentry *tlower_dentry = NULL; + struct dentry *lower_dir_dentry; + struct dentry *tlower_dir_dentry = NULL; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + lower_dentry = ecryptfs_lower_dentry(dentry); + if (!(tdentry = dget(dentry))) { + err = -EINVAL; + ecryptfs_printk(0, KERN_ERR, "Error dget'ing dentry [%p]\n", + dentry); + goto out; + } + lower_dir_dentry = lock_parent(lower_dentry); + if (!(tlower_dentry = dget(lower_dentry))) { + err = -EINVAL; + ecryptfs_printk(0, KERN_ERR, "Error dget'ing lower_dentry " + "[%p]\n", lower_dentry); + goto out; + } + err = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry); + if (!err) { + d_delete(tlower_dentry); + tlower_dentry = NULL; + } + ecryptfs_copy_attr_times(dir, lower_dir_dentry->d_inode); + dir->i_nlink = lower_dir_dentry->d_inode->i_nlink; + unlock_dir(lower_dir_dentry); + if (!err) + d_drop(dentry); +out: + if (tdentry) + dput(tdentry); + if (tlower_dentry) + dput(tlower_dentry); + if (tlower_dir_dentry) + dput(tlower_dir_dentry); + ecryptfs_printk(1, KERN_NOTICE, "Exit; err = [%d]\n", err); + return err; +} + +static int +ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) +{ + int err; + struct dentry *lower_dentry; + struct dentry *lower_dir_dentry; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + lower_dentry = ecryptfs_lower_dentry(dentry); + lower_dir_dentry = lock_parent(lower_dentry); + err = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev); + if (err || !lower_dentry->d_inode) + goto out; + err = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); + if (err) + goto out; + ecryptfs_copy_attr_timesizes(dir, lower_dir_dentry->d_inode); +out: + unlock_dir(lower_dir_dentry); + if (!dentry->d_inode) + d_drop(dentry); + return err; +} + +static int +ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + int err; + struct dentry *lower_old_dentry; + struct dentry *lower_new_dentry; + struct dentry *lower_old_dir_dentry; + struct dentry *lower_new_dir_dentry; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + lower_old_dentry = ecryptfs_lower_dentry(old_dentry); + lower_new_dentry = ecryptfs_lower_dentry(new_dentry); + dget(lower_old_dentry); + dget(lower_new_dentry); + lower_old_dir_dentry = dget_parent(lower_old_dentry); + lower_new_dir_dentry = dget_parent(lower_new_dentry); + lock_rename(lower_old_dir_dentry, lower_new_dir_dentry); + err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry, + lower_new_dir_dentry->d_inode, lower_new_dentry); + if (err) + goto out_lock; + ecryptfs_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode); + if (new_dir != old_dir) + ecryptfs_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode); +out_lock: + unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry); + dput(lower_new_dentry); + dput(lower_old_dentry); + return err; +} + +static int +ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz) +{ + int err; + struct dentry *lower_dentry; + char *decoded_name; + char *lower_buf; + mm_segment_t old_fs; + struct ecryptfs_crypt_stats *crypt_stats; + + ecryptfs_printk(1, KERN_NOTICE, "Enter\n"); + lower_dentry = ecryptfs_lower_dentry(dentry); + if (!lower_dentry->d_inode->i_op || + !lower_dentry->d_inode->i_op->readlink) { + err = -EINVAL; + goto out; + } + /* Released in this function */ + lower_buf = kmalloc(bufsiz, GFP_KERNEL); + if (lower_buf == NULL) { + ecryptfs_printk(0, KERN_ERR, "Out of memory\n"); + err = -ENOMEM; + goto out; + } + old_fs = get_fs(); + set_fs(get_ds()); + ecryptfs_printk(1, KERN_NOTICE, "Calling readlink w/ " + "lower_dentry->d_name.name = [%s]\n", + lower_dentry->d_name.name); + err = lower_dentry->d_inode->i_op->readlink(lower_dentry, + (char __user *)lower_buf, + bufsiz); + set_fs(old_fs); + if (err >= 0) { + crypt_stats = NULL; + err = ecryptfs_decode_filename(lower_buf, err, + &decoded_name, + ECRYPTFS_DO_DOTS, crypt_stats); + if (err == -ENOMEM) + goto out_free_lower_buf; + if (err > 0) { + ecryptfs_printk(1, KERN_NOTICE, "Copying [%d] bytes " + "to userspace: [%*s]\n", err, err, + decoded_name); + if (copy_to_user(buf, decoded_name, err)) + err = -EFAULT; + } + kfree(decoded_name); + ecryptfs_copy_attr_atime(dentry->d_inode, + lower_dentry->d_inode); + } +out_free_lower_buf: + kfree(lower_buf); +out: + ecryptfs_printk(1, KERN_NOTICE, "Exit; err = [%d]\n", err); + return err; +} + +static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + char *buf; + int len = PAGE_SIZE, rc; + mm_segment_t old_fs; + + ecryptfs_printk(1, KERN_NOTICE, "Enter; dentry->d_name.name = [%s]\n", + dentry->d_name.name); + /* Released in ecryptfs_put_link(); only release here on error */ + buf = kmalloc(len, GFP_KERNEL); + if (!buf) { + rc = -ENOMEM; + goto out; + } + old_fs = get_fs(); + set_fs(get_ds()); + ecryptfs_printk(1, KERN_NOTICE, "Calling readlink w/ " + "dentry->d_name.name = [%s]\n", dentry->d_name.name); + rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len); + buf[rc] = '\0'; + set_fs(old_fs); + if (rc < 0) + goto out_free; + rc = 0; + nd_set_link(nd, buf); + goto out; +out_free: + kfree(buf); +out: + return ERR_PTR(rc); +} + +static inline void +ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr) +{ + /* Free the char* */ + kfree(nd_get_link(nd)); +} + +/** + * Calculate the requried size of the lower file based on the specified size + * of the upper file. This calculation is based on the number of headers in + * the underlying file, the number of records (IV/HMAC/IV+HMAC) per page + * that can be stored, and the extent size of the underlying file (page size). + * + * @param crypt_stats crypt_stats associated with file + * @param upper_size size of the upper file + * @return calculated size of the lower file. + */ +static loff_t +upper_size_to_lower_size(struct ecryptfs_crypt_stats *crypt_stats, + loff_t upper_size) +{ + int upper_idx = 0; + int lower_idx; + loff_t lower_size = upper_size; + + ecryptfs_printk(1, KERN_NOTICE, "Enter; upper_size = [%lld]\n", + upper_size); + /* TODO: Does this need to be based on the extent size? */ + if (likely(upper_size > 0)) + upper_idx = (upper_size - 1) >> PAGE_CACHE_SHIFT; + else if (!upper_size) + upper_idx = 0; + else /* Sanity check, size shouldn't be negative */ + BUG(); + lower_idx = ecryptfs_pg_idx_to_lwr_pg_idx(crypt_stats, upper_idx); + lower_size = ((lower_idx + 1) << PAGE_CACHE_SHIFT); + ecryptfs_printk(1, KERN_NOTICE, "Exit; lower_size = [%lld]\n", + lower_size); + return lower_size; +} + +/** + * Function to handle truncations modifying the size of the file. Note + * that the file sizes are interpolated. When expanding, we are simply + * writing strings of 0's out. When truncating, we need to modify the + * underlying file size accordingly to the page index interpolations. + * + * N.B. No claims are made about integrety of the encrypted data when + * shrinking a file. (But its probably going to be lost) + * + * TODO: Support holes. Should we also be supporting preservation of + * the encrypted data? + * + * @param dentry The ecryptfs layer dentry + * @param new_length The length to expand the file to + * @return Zero on success; non-zero otherwise + */ +int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) +{ + int rc = 0; + struct inode *inode = dentry->d_inode; + struct dentry *lower_dentry; + struct file fake_ecryptfs_file, *lower_file = NULL; + struct ecryptfs_crypt_stats *crypt_stats; + loff_t i_size = i_size_read(inode); + loff_t lower_size_before_truncate; + loff_t lower_size_after_truncate; + + ecryptfs_printk(1, KERN_NOTICE, "Enter; dentry = [%p], new_length = " + "[%lld], i_size_read(inode) = [%lld]\n", + dentry, new_length, i_size); + /* Sanity checks */ + if (unlikely((new_length == i_size))) + goto out; + crypt_stats = &ECRYPTFS_INODE_TO_PRIVATE(dentry->d_inode)->crypt_stats; + if (unlikely(!crypt_stats)) { + ecryptfs_printk(0, KERN_ERR, "NULL crypt_stats on dentry with " + "d_name.name = [%s]\n", dentry->d_name.name); + rc = -EINVAL; + goto out; + } + + /* Set up a fake ecryptfs file, this is used to interface with the file + * in the underlying filesystem so that the truncation has an effect + * there as well. */ + memset(&fake_ecryptfs_file, 0, sizeof(struct file)); + fake_ecryptfs_file.f_dentry = dentry; + /* Released at out_free: */ + ECRYPTFS_FILE_TO_PRIVATE_SM(&fake_ecryptfs_file) = + kmem_cache_alloc(ecryptfs_file_info_cache, SLAB_KERNEL); + if (unlikely(!ECRYPTFS_FILE_TO_PRIVATE(&fake_ecryptfs_file))) { + rc = -ENOMEM; + goto out; + } + lower_dentry = ecryptfs_lower_dentry(dentry); + /* This dget & mntget is released through fput at out_fput: */ + dget(lower_dentry); + mntget(ECRYPTFS_SUPERBLOCK_TO_PRIVATE(inode->i_sb)->lower_mnt); + lower_file = dentry_open( + lower_dentry, + ECRYPTFS_SUPERBLOCK_TO_PRIVATE(inode->i_sb)->lower_mnt, O_RDWR); + if (unlikely(IS_ERR(lower_file))) { + rc = PTR_ERR(lower_file); + goto out_free; + } + ECRYPTFS_FILE_TO_LOWER(&fake_ecryptfs_file) = lower_file; + + /* Switch on growing or shrinking file */ + if (new_length > i_size) { + rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length); + if (rc) { + ecryptfs_printk(0, KERN_ERR, + "Problem with fill_zeros\n"); + goto out_fput; + } + i_size_write(inode, new_length); + rc = ecryptfs_write_inode_size_to_header(lower_file, + lower_dentry->d_inode, + inode); + if (rc) { + ecryptfs_printk(0, KERN_ERR, + "Problem with ecryptfs_write" + "_inode_size\n"); + goto out_fput; + } + } else { /* new_length < i_size_read(inode) */ + vmtruncate(inode, new_length); + ecryptfs_write_inode_size_to_header(lower_file, + lower_dentry->d_inode, + inode); + /* We are reducing the size of the ecryptfs file, and need to + * know if we need to reduce the size of the lower file. */ + lower_size_before_truncate = + upper_size_to_lower_size(crypt_stats, i_size); + lower_size_after_truncate = + upper_size_to_lower_size(crypt_stats, new_length); + if (lower_size_after_truncate < lower_size_before_truncate) + vmtruncate(lower_dentry->d_inode, + lower_size_after_truncate); + } + /* Update the access times */ + lower_dentry->d_inode->i_mtime = CURRENT_TIME; + lower_dentry->d_inode->i_ctime = CURRENT_TIME; + mark_inode_dirty_sync(inode); +out_fput: + /* TODO: Determine which of these need to really be called. + * filp_close() will call fput(), but do we need to do the extra work + * that filp_close() provides? + if (lower_file) + filp_close(lower_file, NULL); + */ + fput(lower_file); +out_free: + if (ECRYPTFS_FILE_TO_PRIVATE(&fake_ecryptfs_file)) + kmem_cache_free(ecryptfs_file_info_cache, + ECRYPTFS_FILE_TO_PRIVATE(&fake_ecryptfs_file)); +out: + ecryptfs_printk(1, KERN_NOTICE, "Exit; rc = [%d]\n", rc); + return rc; +} + +static int +ecryptfs_permission(struct inode *inode, int mask, struct nameidata *nd) +{ + struct inode *lower_inode; + int rc = 0; + + ecryptfs_printk(1, KERN_NOTICE, "Enter; inode = [%p], mask=[%d], nd =" + "[%p]\n", inode, mask, nd); + lower_inode = ECRYPTFS_INODE_TO_LOWER(inode); + if (nd) + ecryptfs_printk(1, KERN_NOTICE, "nd->dentry = [%p]\n", + nd->dentry); + rc = permission(lower_inode, mask, nd); + ecryptfs_printk(1, KERN_NOTICE, "Exit; rc = [%d]\n", rc); + return rc; +} + +/** + * Updates the metadata of an inode. If the update is to the size + * i.e. truncation, then ecryptfs_truncate will handle the size modification + * of both the ecryptfs inode and the lower inode. + * + * All other metadata changes will be passed right to the lower filesystem, + * and we will just update our inode to look like the lower. + * + * @param dentry dentry handle to the inode to modify + * @param ia structure with flags of what to change and values + */ +static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) +{ + int err = 0; + struct dentry *lower_dentry; + struct inode *inode; + struct inode *lower_inode; + struct ecryptfs_crypt_stats *crypt_stats; + ecryptfs_printk(1, KERN_NOTICE, "Enter; dentry->d_name.name = [%s]\n", + dentry->d_name.name); + crypt_stats = &ECRYPTFS_INODE_TO_PRIVATE(dentry->d_inode)->crypt_stats; + lower_dentry = ecryptfs_lower_dentry(dentry); + inode = dentry->d_inode; + lower_inode = ECRYPTFS_INODE_TO_LOWER(inode); + if (ia->ia_valid & ATTR_SIZE) { + ecryptfs_printk(1, KERN_NOTICE, + "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n", + ia->ia_valid, ATTR_SIZE); + err = ecryptfs_truncate(dentry, ia->ia_size); + /* ecryptfs_truncate handles resizing of the lower file */ + ia->ia_valid &= ~ATTR_SIZE; + ecryptfs_printk(1, KERN_NOTICE, "ia->ia_valid = [%x]\n", + ia->ia_valid); + if (err < 0) + goto out; + } + err = notify_change(lower_dentry, ia); +out: + ecryptfs_copy_attr_all(inode, lower_inode); + ecryptfs_printk(1, KERN_NOTICE, "Exit; err = [%d]\n"); + return err; +} + +struct inode_operations ecryptfs_symlink_iops = { + .readlink = ecryptfs_readlink, + .follow_link = ecryptfs_follow_link, + .put_link = ecryptfs_put_link, + .permission = ecryptfs_permission, + .setattr = ecryptfs_setattr, +}; + +struct inode_operations ecryptfs_dir_iops = { + .create = ecryptfs_create, + .lookup = ecryptfs_lookup, + .link = ecryptfs_link, + .unlink = ecryptfs_unlink, + .symlink = ecryptfs_symlink, + .mkdir = ecryptfs_mkdir, + .rmdir = ecryptfs_rmdir, + .mknod = ecryptfs_mknod, + .rename = ecryptfs_rename, + .permission = ecryptfs_permission, + .setattr = ecryptfs_setattr, +}; + +struct inode_operations ecryptfs_main_iops = { + .permission = ecryptfs_permission, + .setattr = ecryptfs_setattr, +}; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/