diff options
Diffstat (limited to 'fs/ecryptfs/mmap.c')
| -rw-r--r-- | fs/ecryptfs/mmap.c | 788 |
1 files changed, 788 insertions, 0 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c new file mode 100644 index 000000000000..924dd90a4cf5 --- /dev/null +++ b/fs/ecryptfs/mmap.c @@ -0,0 +1,788 @@ +/** + * eCryptfs: Linux filesystem encryption layer + * This is where eCryptfs coordinates the symmetric encryption and + * decryption of the file data as it passes between the lower + * encrypted file and the upper decrypted file. + * + * Copyright (C) 1997-2003 Erez Zadok + * Copyright (C) 2001-2003 Stony Brook University + * Copyright (C) 2004-2006 International Business Machines Corp. + * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA + * 02111-1307, USA. + */ + +#include <linux/pagemap.h> +#include <linux/writeback.h> +#include <linux/page-flags.h> +#include <linux/mount.h> +#include <linux/file.h> +#include <linux/crypto.h> +#include <linux/scatterlist.h> +#include "ecryptfs_kernel.h" + +struct kmem_cache *ecryptfs_lower_page_cache; + +/** + * ecryptfs_get1page + * + * Get one page from cache or lower f/s, return error otherwise. + * + * Returns unlocked and up-to-date page (if ok), with increased + * refcnt. + */ +static struct page *ecryptfs_get1page(struct file *file, int index) +{ + struct page *page; + struct dentry *dentry; + struct inode *inode; + struct address_space *mapping; + + dentry = file->f_dentry; + inode = dentry->d_inode; + mapping = inode->i_mapping; + page = read_cache_page(mapping, index, + (filler_t *)mapping->a_ops->readpage, + (void *)file); + if (IS_ERR(page)) + goto out; + wait_on_page_locked(page); +out: + return page; +} + +static +int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros); + +/** + * ecryptfs_fill_zeros + * @file: The ecryptfs file + * @new_length: The new length of the data in the underlying file; + * everything between the prior end of the file and the + * new end of the file will be filled with zero's. + * new_length must be greater than current length + * + * Function for handling lseek-ing past the end of the file. + * + * This function does not support shrinking, only growing a file. + * + * Returns zero on success; non-zero otherwise. + */ +int ecryptfs_fill_zeros(struct file *file, loff_t new_length) +{ + int rc = 0; + struct dentry *dentry = file->f_dentry; + struct inode *inode = dentry->d_inode; + pgoff_t old_end_page_index = 0; + pgoff_t index = old_end_page_index; + int old_end_pos_in_page = -1; + pgoff_t new_end_page_index; + int new_end_pos_in_page; + loff_t cur_length = i_size_read(inode); + + if (cur_length != 0) { + index = old_end_page_index = + ((cur_length - 1) >> PAGE_CACHE_SHIFT); + old_end_pos_in_page = ((cur_length - 1) & ~PAGE_CACHE_MASK); + } + new_end_page_index = ((new_length - 1) >> PAGE_CACHE_SHIFT); + new_end_pos_in_page = ((new_length - 1) & ~PAGE_CACHE_MASK); + ecryptfs_printk(KERN_DEBUG, "old_end_page_index = [0x%.16x]; " + "old_end_pos_in_page = [%d]; " + "new_end_page_index = [0x%.16x]; " + "new_end_pos_in_page = [%d]\n", + old_end_page_index, old_end_pos_in_page, + new_end_page_index, new_end_pos_in_page); + if (old_end_page_index == new_end_page_index) { + /* Start and end are in the same page; we just need to + * set a portion of the existing page to zero's */ + rc = write_zeros(file, index, (old_end_pos_in_page + 1), + (new_end_pos_in_page - old_end_pos_in_page)); + if (rc) + ecryptfs_printk(KERN_ERR, "write_zeros(file=[%p], " + "index=[0x%.16x], " + "old_end_pos_in_page=[d], " + "(PAGE_CACHE_SIZE - new_end_pos_in_page" + "=[%d]" + ")=[d]) returned [%d]\n", file, index, + old_end_pos_in_page, + new_end_pos_in_page, + (PAGE_CACHE_SIZE - new_end_pos_in_page), + rc); + goto out; + } + /* Fill the remainder of the previous last page with zeros */ + rc = write_zeros(file, index, (old_end_pos_in_page + 1), + ((PAGE_CACHE_SIZE - 1) - old_end_pos_in_page)); + if (rc) { + ecryptfs_printk(KERN_ERR, "write_zeros(file=[%p], " + "index=[0x%.16x], old_end_pos_in_page=[d], " + "(PAGE_CACHE_SIZE - old_end_pos_in_page)=[d]) " + "returned [%d]\n", file, index, + old_end_pos_in_page, + (PAGE_CACHE_SIZE - old_end_pos_in_page), rc); + goto out; + } + index++; + while (index < new_end_page_index) { + /* Fill all intermediate pages with zeros */ + rc = write_zeros(file, index, 0, PAGE_CACHE_SIZE); + if (rc) { + ecryptfs_printk(KERN_ERR, "write_zeros(file=[%p], " + "index=[0x%.16x], " + "old_end_pos_in_page=[d], " + "(PAGE_CACHE_SIZE - new_end_pos_in_page" + "=[%d]" + ")=[d]) returned [%d]\n", file, index, + old_end_pos_in_page, + new_end_pos_in_page, + (PAGE_CACHE_SIZE - new_end_pos_in_page), + rc); + goto out; + } + index++; + } + /* Fill the portion at the beginning of the last new page with + * zero's */ + rc = write_zeros(file, index, 0, (new_end_pos_in_page + 1)); + if (rc) { + ecryptfs_printk(KERN_ERR, "write_zeros(file=" + "[%p], index=[0x%.16x], 0, " + "new_end_pos_in_page=[%d]" + "returned [%d]\n", file, index, + new_end_pos_in_page, rc); + goto out; + } +out: + return rc; +} + +/** + * ecryptfs_writepage + * @page: Page that is locked before this call is made + * + * Returns zero on success; non-zero otherwise + */ +static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc) +{ + struct ecryptfs_page_crypt_context ctx; + int rc; + + ctx.page = page; + ctx.mode = ECRYPTFS_WRITEPAGE_MODE; + ctx.param.wbc = wbc; + rc = ecryptfs_encrypt_page(&ctx); + if (rc) { + ecryptfs_printk(KERN_WARNING, "Error encrypting " + "page (upper index [0x%.16x])\n", page->index); + ClearPageUptodate(page); + goto out; + } + SetPageUptodate(page); + unlock_page(page); +out: + return rc; +} + +/** + * Reads the data from the lower file file at index lower_page_index + * and copies that data into page. + * + * @param page Page to fill + * @param lower_page_index Index of the page in the lower file to get + */ +int ecryptfs_do_readpage(struct file *file, struct page *page, + pgoff_t lower_page_index) +{ + int rc; + struct dentry *dentry; + struct file *lower_file; + struct dentry *lower_dentry; + struct inode *inode; + struct inode *lower_inode; + char *page_data; + struct page *lower_page = NULL; + char *lower_page_data; + const struct address_space_operations *lower_a_ops; + + dentry = file->f_dentry; + lower_file = ecryptfs_file_to_lower(file); + lower_dentry = ecryptfs_dentry_to_lower(dentry); + inode = dentry->d_inode; + lower_inode = ecryptfs_inode_to_lower(inode); + lower_a_ops = lower_inode->i_mapping->a_ops; + lower_page = read_cache_page(lower_inode->i_mapping, lower_page_index, + (filler_t *)lower_a_ops->readpage, + (void *)lower_file); + if (IS_ERR(lower_page)) { + rc = PTR_ERR(lower_page); + lower_page = NULL; + ecryptfs_printk(KERN_ERR, "Error reading from page cache\n"); + goto out; + } + wait_on_page_locked(lower_page); + page_data = (char *)kmap(page); + if (!page_data) { + rc = -ENOMEM; + ecryptfs_printk(KERN_ERR, "Error mapping page\n"); + goto out; + } + lower_page_data = (char *)kmap(lower_page); + if (!lower_page_data) { + rc = -ENOMEM; + ecryptfs_printk(KERN_ERR, "Error mapping page\n"); + kunmap(page); + goto out; + } + memcpy(page_data, lower_page_data, PAGE_CACHE_SIZE); + kunmap(lower_page); + kunmap(page); + rc = 0; +out: + if (likely(lower_page)) + page_cache_release(lower_page); + if (rc == 0) + SetPageUptodate(page); + else + ClearPageUptodate(page); + return rc; +} + +/** + * ecryptfs_readpage + * @file: This is an ecryptfs file + * @page: ecryptfs associated page to stick the read data into + * + * Read in a page, decrypting if necessary. + * + * Returns zero on success; non-zero on error. + */ +static int ecryptfs_readpage(struct file *file, struct page *page) +{ + int rc = 0; + struct ecryptfs_crypt_stat *crypt_stat; + + BUG_ON(!(file && file->f_dentry && file->f_dentry->d_inode)); + crypt_stat = + &ecryptfs_inode_to_private(file->f_dentry->d_inode)->crypt_stat; + if (!crypt_stat + || !ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED) + || ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE)) { + ecryptfs_printk(KERN_DEBUG, + "Passing through unencrypted page\n"); + rc = ecryptfs_do_readpage(file, page, page->index); + if (rc) { + ecryptfs_printk(KERN_ERR, "Error reading page; rc = " + "[%d]\n", rc); + goto out; + } + } else { + rc = ecryptfs_decrypt_page(file, page); + if (rc) { + + ecryptfs_printk(KERN_ERR, "Error decrypting page; " + "rc = [%d]\n", rc); + goto out; + } + } + SetPageUptodate(page); +out: + if (rc) + ClearPageUptodate(page); + ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n", + page->index); + unlock_page(page); + return rc; +} + +static int fill_zeros_to_end_of_page(struct page *page, unsigned int to) +{ + struct inode *inode = page->mapping->host; + int end_byte_in_page; + int rc = 0; + char *page_virt; + + if ((i_size_read(inode) / PAGE_CACHE_SIZE) == page->index) { + end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE; + if (to > end_byte_in_page) + end_byte_in_page = to; + page_virt = kmap(page); + if (!page_virt) { + rc = -ENOMEM; + ecryptfs_printk(KERN_WARNING, + "Could not map page\n"); + goto out; + } + memset((page_virt + end_byte_in_page), 0, + (PAGE_CACHE_SIZE - end_byte_in_page)); + kunmap(page); + } +out: + return rc; +} + +static int ecryptfs_prepare_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + int rc = 0; + + kmap(page); + if (from == 0 && to == PAGE_CACHE_SIZE) + goto out; /* If we are writing a full page, it will be + up to date. */ + if (!PageUptodate(page)) + rc = ecryptfs_do_readpage(file, page, page->index); +out: + return rc; +} + +int ecryptfs_grab_and_map_lower_page(struct page **lower_page, + char **lower_virt, + struct inode *lower_inode, + unsigned long lower_page_index) +{ + int rc = 0; + + (*lower_page) = grab_cache_page(lower_inode->i_mapping, + lower_page_index); + if (!(*lower_page)) { + ecryptfs_printk(KERN_ERR, "grab_cache_page for " + "lower_page_index = [0x%.16x] failed\n", + lower_page_index); + rc = -EINVAL; + goto out; + } + if (lower_virt) + (*lower_virt) = kmap((*lower_page)); + else + kmap((*lower_page)); +out: + return rc; +} + +int ecryptfs_writepage_and_release_lower_page(struct page *lower_page, + struct inode *lower_inode, + struct writeback_control *wbc) +{ + int rc = 0; + + rc = lower_inode->i_mapping->a_ops->writepage(lower_page, wbc); + if (rc) { + ecryptfs_printk(KERN_ERR, "Error calling lower writepage(); " + "rc = [%d]\n", rc); + goto out; + } + lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME; + page_cache_release(lower_page); +out: + return rc; +} + +static void ecryptfs_unmap_and_release_lower_page(struct page *lower_page) +{ + kunmap(lower_page); + ecryptfs_printk(KERN_DEBUG, "Unlocking lower page with index = " + "[0x%.16x]\n", lower_page->index); + unlock_page(lower_page); + page_cache_release(lower_page); +} + +/** + * ecryptfs_write_inode_size_to_header + * + * Writes the lower file size to the first 8 bytes of the header. + * + * 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) +{ + int rc = 0; + struct page *header_page; + char *header_virt; + const struct address_space_operations *lower_a_ops; + u64 file_size; + + rc = ecryptfs_grab_and_map_lower_page(&header_page, &header_virt, + lower_inode, 0); + if (rc) { + ecryptfs_printk(KERN_ERR, "grab_cache_page for header page " + "failed\n"); + goto out; + } + lower_a_ops = lower_inode->i_mapping->a_ops; + rc = lower_a_ops->prepare_write(lower_file, header_page, 0, 8); + file_size = (u64)i_size_read(inode); + ecryptfs_printk(KERN_DEBUG, "Writing size: [0x%.16x]\n", file_size); + file_size = cpu_to_be64(file_size); + memcpy(header_virt, &file_size, sizeof(u64)); + rc = lower_a_ops->commit_write(lower_file, header_page, 0, 8); + if (rc < 0) + ecryptfs_printk(KERN_ERR, "Error commiting header page " + "write\n"); + ecryptfs_unmap_and_release_lower_page(header_page); + lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME; + mark_inode_dirty_sync(inode); +out: + return rc; +} + +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, + int region_bytes) +{ + int rc = 0; + + rc = ecryptfs_grab_and_map_lower_page(lower_page, NULL, lower_inode, + lower_page_index); + if (rc) { + ecryptfs_printk(KERN_ERR, "Error attempting to grab and map " + "lower page with index [0x%.16x]\n", + lower_page_index); + goto out; + } + rc = lower_inode->i_mapping->a_ops->prepare_write(lower_file, + (*lower_page), + byte_offset, + region_bytes); + if (rc) { + ecryptfs_printk(KERN_ERR, "prepare_write for " + "lower_page_index = [0x%.16x] failed; rc = " + "[%d]\n", lower_page_index, rc); + } +out: + if (rc && (*lower_page)) { + ecryptfs_unmap_and_release_lower_page(*lower_page); + (*lower_page) = NULL; + } + return rc; +} + +/** + * ecryptfs_commit_lower_page + * + * Returns zero on success; non-zero on error + */ +int +ecryptfs_commit_lower_page(struct page *lower_page, struct inode *lower_inode, + struct file *lower_file, int byte_offset, + int region_size) +{ + int rc = 0; + + rc = lower_inode->i_mapping->a_ops->commit_write( + lower_file, lower_page, byte_offset, region_size); + if (rc < 0) { + ecryptfs_printk(KERN_ERR, + "Error committing write; rc = [%d]\n", rc); + } else + rc = 0; + ecryptfs_unmap_and_release_lower_page(lower_page); + return rc; +} + +/** + * ecryptfs_copy_page_to_lower + * + * Used for plaintext pass-through; no page index interpolation + * required. + */ +int ecryptfs_copy_page_to_lower(struct page *page, struct inode *lower_inode, + struct file *lower_file) +{ + int rc = 0; + struct page *lower_page; + + rc = ecryptfs_get_lower_page(&lower_page, lower_inode, lower_file, + page->index, 0, PAGE_CACHE_SIZE); + if (rc) { + ecryptfs_printk(KERN_ERR, "Error attempting to get page " + "at index [0x%.16x]\n", page->index); + goto out; + } + /* TODO: aops */ + memcpy((char *)page_address(lower_page), page_address(page), + PAGE_CACHE_SIZE); + rc = ecryptfs_commit_lower_page(lower_page, lower_inode, lower_file, + 0, PAGE_CACHE_SIZE); + if (rc) + ecryptfs_printk(KERN_ERR, "Error attempting to commit page " + "at index [0x%.16x]\n", page->index); +out: + return rc; +} + +static int +process_new_file(struct ecryptfs_crypt_stat *crypt_stat, + struct file *file, struct inode *inode) +{ + struct page *header_page; + const struct address_space_operations *lower_a_ops; + struct inode *lower_inode; + struct file *lower_file; + char *header_virt; + int rc = 0; + int current_header_page = 0; + int header_pages; + int more_header_data_to_be_written = 1; + + lower_inode = ecryptfs_inode_to_lower(inode); + lower_file = ecryptfs_file_to_lower(file); + lower_a_ops = lower_inode->i_mapping->a_ops; + header_pages = ((crypt_stat->header_extent_size + * crypt_stat->num_header_extents_at_front) + / PAGE_CACHE_SIZE); + BUG_ON(header_pages < 1); + while (current_header_page < header_pages) { + rc = ecryptfs_grab_and_map_lower_page(&header_page, + &header_virt, + lower_inode, + current_header_page); + if (rc) { + ecryptfs_printk(KERN_ERR, "grab_cache_page for " + "header page [%d] failed; rc = [%d]\n", + current_header_page, rc); + goto out; + } + rc = lower_a_ops->prepare_write(lower_file, header_page, 0, + PAGE_CACHE_SIZE); + if (rc) { + ecryptfs_printk(KERN_ERR, "Error preparing to write " + "header page out; rc = [%d]\n", rc); + goto out; + } + memset(header_virt, 0, PAGE_CACHE_SIZE); + if (more_header_data_to_be_written) { + rc = ecryptfs_write_headers_virt(header_virt, + crypt_stat, + file->f_dentry); + if (rc) { + ecryptfs_printk(KERN_WARNING, "Error " + "generating header; rc = " + "[%d]\n", rc); + rc = -EIO; + memset(header_virt, 0, PAGE_CACHE_SIZE); + ecryptfs_unmap_and_release_lower_page( + header_page); + goto out; + } + if (current_header_page == 0) + memset(header_virt, 0, 8); + more_header_data_to_be_written = 0; + } + rc = lower_a_ops->commit_write(lower_file, header_page, 0, + PAGE_CACHE_SIZE); + ecryptfs_unmap_and_release_lower_page(header_page); + if (rc < 0) { + ecryptfs_printk(KERN_ERR, + "Error commiting header page write; " + "rc = [%d]\n", rc); + break; + } + current_header_page++; + } + if (rc >= 0) { + rc = 0; + ecryptfs_printk(KERN_DEBUG, "lower_inode->i_blocks = " + "[0x%.16x]\n", lower_inode->i_blocks); + i_size_write(inode, 0); + lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME; + mark_inode_dirty_sync(inode); + } + ecryptfs_printk(KERN_DEBUG, "Clearing ECRYPTFS_NEW_FILE flag in " + "crypt_stat at memory location [%p]\n", crypt_stat); + ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE); +out: + return rc; +} + +/** + * ecryptfs_commit_write + * @file: The eCryptfs file object + * @page: The eCryptfs page + * @from: Ignored (we rotate the page IV on each write) + * @to: Ignored + * + * This is where we encrypt the data and pass the encrypted data to + * the lower filesystem. In OpenPGP-compatible mode, we operate on + * entire underlying packets. + */ +static int ecryptfs_commit_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + struct ecryptfs_page_crypt_context ctx; + loff_t pos; + struct inode *inode; + struct inode *lower_inode; + struct file *lower_file; + struct ecryptfs_crypt_stat *crypt_stat; + int rc; + + inode = page->mapping->host; + lower_inode = ecryptfs_inode_to_lower(inode); + lower_file = ecryptfs_file_to_lower(file); + mutex_lock(&lower_inode->i_mutex); + crypt_stat = + &ecryptfs_inode_to_private(file->f_dentry->d_inode)->crypt_stat; + if (ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE)) { + ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in " + "crypt_stat at memory location [%p]\n", crypt_stat); + rc = process_new_file(crypt_stat, file, inode); + if (rc) { + ecryptfs_printk(KERN_ERR, "Error processing new " + "file; rc = [%d]\n", rc); + goto out; + } + } else + ecryptfs_printk(KERN_DEBUG, "Not a new file\n"); + ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" + "(page w/ index = [0x%.16x], to = [%d])\n", page->index, + to); + rc = fill_zeros_to_end_of_page(page, to); + if (rc) { + ecryptfs_printk(KERN_WARNING, "Error attempting to fill " + "zeros in page with index = [0x%.16x]\n", + page->index); + goto out; + } + ctx.page = page; + ctx.mode = ECRYPTFS_PREPARE_COMMIT_MODE; + ctx.param.lower_file = lower_file; + rc = ecryptfs_encrypt_page(&ctx); + if (rc) { + ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper " + "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)) { + i_size_write(inode, pos); + 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); + lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME; + mark_inode_dirty_sync(inode); +out: + kunmap(page); /* mapped in prior call (prepare_write) */ + if (rc < 0) + ClearPageUptodate(page); + else + SetPageUptodate(page); + mutex_unlock(&lower_inode->i_mutex); + return rc; +} + +/** + * write_zeros + * @file: The ecryptfs file + * @index: The index in which we are writing + * @start: The position after the last block of data + * @num_zeros: The number of zeros to write + * + * Write a specified number of zero's to a page. + * + * (start + num_zeros) must be less than or equal to PAGE_CACHE_SIZE + */ +static +int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros) +{ + int rc = 0; + struct page *tmp_page; + + tmp_page = ecryptfs_get1page(file, index); + if (IS_ERR(tmp_page)) { + ecryptfs_printk(KERN_ERR, "Error getting page at index " + "[0x%.16x]\n", index); + rc = PTR_ERR(tmp_page); + goto out; + } + kmap(tmp_page); + rc = ecryptfs_prepare_write(file, tmp_page, start, start + num_zeros); + if (rc) { + ecryptfs_printk(KERN_ERR, "Error preparing to write zero's " + "to remainder of page at index [0x%.16x]\n", + index); + kunmap(tmp_page); + page_cache_release(tmp_page); + goto out; + } + memset(((char *)page_address(tmp_page) + start), 0, num_zeros); + rc = ecryptfs_commit_write(file, tmp_page, start, start + num_zeros); + if (rc < 0) { + ecryptfs_printk(KERN_ERR, "Error attempting to write zero's " + "to remainder of page at index [0x%.16x]\n", + index); + kunmap(tmp_page); + page_cache_release(tmp_page); + goto out; + } + rc = 0; + kunmap(tmp_page); + page_cache_release(tmp_page); +out: + return rc; +} + +static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block) +{ + int rc = 0; + struct inode *inode; + struct inode *lower_inode; + + inode = (struct inode *)mapping->host; + lower_inode = ecryptfs_inode_to_lower(inode); + if (lower_inode->i_mapping->a_ops->bmap) + rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping, + block); + return rc; +} + +static void ecryptfs_sync_page(struct page *page) +{ + struct inode *inode; + struct inode *lower_inode; + struct page *lower_page; + + inode = page->mapping->host; + lower_inode = ecryptfs_inode_to_lower(inode); + /* NOTE: Recently swapped with grab_cache_page(), since + * sync_page() just makes sure that pending I/O gets done. */ + lower_page = find_lock_page(lower_inode->i_mapping, page->index); + if (!lower_page) { + ecryptfs_printk(KERN_DEBUG, "find_lock_page failed\n"); + return; + } + lower_page->mapping->a_ops->sync_page(lower_page); + ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n", + lower_page->index); + unlock_page(lower_page); + page_cache_release(lower_page); +} + +struct address_space_operations ecryptfs_aops = { + .writepage = ecryptfs_writepage, + .readpage = ecryptfs_readpage, + .prepare_write = ecryptfs_prepare_write, + .commit_write = ecryptfs_commit_write, + .bmap = ecryptfs_bmap, + .sync_page = ecryptfs_sync_page, +}; |