diff options
Diffstat (limited to 'fs/ecryptfs/mmap.c')
| -rw-r--r-- | fs/ecryptfs/mmap.c | 96 |
1 files changed, 89 insertions, 7 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c index 0af3aa3b4b3e..ba3650d03c48 100644 --- a/fs/ecryptfs/mmap.c +++ b/fs/ecryptfs/mmap.c @@ -6,7 +6,7 @@ * * Copyright (C) 1997-2003 Erez Zadok * Copyright (C) 2001-2003 Stony Brook University - * Copyright (C) 2004-2006 International Business Machines Corp. + * Copyright (C) 2004-2007 International Business Machines Corp. * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> * * This program is free software; you can redistribute it and/or @@ -308,6 +308,9 @@ out: return rc; } +/** + * Called with lower inode mutex held. + */ static int fill_zeros_to_end_of_page(struct page *page, unsigned int to) { struct inode *inode = page->mapping->host; @@ -407,10 +410,9 @@ static void ecryptfs_unmap_and_release_lower_page(struct page *lower_page) * * Returns zero on success; non-zero on error. */ -int -ecryptfs_write_inode_size_to_header(struct file *lower_file, - struct inode *lower_inode, - struct inode *inode) +static int ecryptfs_write_inode_size_to_header(struct file *lower_file, + struct inode *lower_inode, + struct inode *inode) { int rc = 0; struct page *header_page; @@ -442,6 +444,80 @@ out: return rc; } +static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode, + struct inode *inode, + struct dentry *ecryptfs_dentry, + int lower_i_mutex_held) +{ + ssize_t size; + void *xattr_virt; + struct dentry *lower_dentry; + u64 file_size; + int rc; + + xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL); + if (!xattr_virt) { + printk(KERN_ERR "Out of memory whilst attempting to write " + "inode size to xattr\n"); + rc = -ENOMEM; + goto out; + } + lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); + if (!lower_dentry->d_inode->i_op->getxattr) { + printk(KERN_WARNING + "No support for setting xattr in lower filesystem\n"); + rc = -ENOSYS; + kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); + goto out; + } + if (!lower_i_mutex_held) + mutex_lock(&lower_dentry->d_inode->i_mutex); + size = lower_dentry->d_inode->i_op->getxattr(lower_dentry, + ECRYPTFS_XATTR_NAME, + xattr_virt, + PAGE_CACHE_SIZE); + if (!lower_i_mutex_held) + mutex_unlock(&lower_dentry->d_inode->i_mutex); + if (size < 0) + size = 8; + file_size = (u64)i_size_read(inode); + file_size = cpu_to_be64(file_size); + memcpy(xattr_virt, &file_size, sizeof(u64)); + if (!lower_i_mutex_held) + mutex_lock(&lower_dentry->d_inode->i_mutex); + rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, + ECRYPTFS_XATTR_NAME, + xattr_virt, size, 0); + if (!lower_i_mutex_held) + mutex_unlock(&lower_dentry->d_inode->i_mutex); + if (rc) + printk(KERN_ERR "Error whilst attempting to write inode size " + "to lower file xattr; rc = [%d]\n", rc); + kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); +out: + return rc; +} + +int +ecryptfs_write_inode_size_to_metadata(struct file *lower_file, + struct inode *lower_inode, + struct inode *inode, + struct dentry *ecryptfs_dentry, + int lower_i_mutex_held) +{ + struct ecryptfs_crypt_stat *crypt_stat; + + crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; + if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) + return ecryptfs_write_inode_size_to_xattr(lower_inode, inode, + ecryptfs_dentry, + lower_i_mutex_held); + else + return ecryptfs_write_inode_size_to_header(lower_file, + lower_inode, + inode); +} + int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode, struct file *lower_file, unsigned long lower_page_index, int byte_offset, @@ -528,6 +604,8 @@ out: return rc; } +struct kmem_cache *ecryptfs_xattr_cache; + /** * ecryptfs_commit_write * @file: The eCryptfs file object @@ -581,7 +659,6 @@ static int ecryptfs_commit_write(struct file *file, struct page *page, "index [0x%.16x])\n", page->index); goto out; } - rc = 0; inode->i_blocks = lower_inode->i_blocks; pos = (page->index << PAGE_CACHE_SHIFT) + to; if (pos > i_size_read(inode)) { @@ -589,7 +666,12 @@ static int ecryptfs_commit_write(struct file *file, struct page *page, ecryptfs_printk(KERN_DEBUG, "Expanded file size to " "[0x%.16x]\n", i_size_read(inode)); } - ecryptfs_write_inode_size_to_header(lower_file, lower_inode, inode); + rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode, + inode, file->f_dentry, + ECRYPTFS_LOWER_I_MUTEX_HELD); + if (rc) + printk(KERN_ERR "Error writing inode size to metadata; " + "rc = [%d]\n", rc); lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME; mark_inode_dirty_sync(inode); out: |