#include <linux/file.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
+#include <asm/unaligned.h>
#include "ecryptfs_kernel.h"
/**
struct ecryptfs_crypt_stat *crypt_stat)
{
size_t written;
- int save_num_header_extents_at_front =
- crypt_stat->num_header_extents_at_front;
+ size_t save_num_header_bytes_at_front =
+ crypt_stat->num_header_bytes_at_front;
- crypt_stat->num_header_extents_at_front = 1;
+ crypt_stat->num_header_bytes_at_front =
+ ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written);
- crypt_stat->num_header_extents_at_front =
- save_num_header_extents_at_front;
+ crypt_stat->num_header_bytes_at_front =
+ save_num_header_bytes_at_front;
}
/**
loff_t view_extent_num = ((((loff_t)page->index)
* num_extents_per_page)
+ extent_num_in_page);
+ size_t num_header_extents_at_front =
+ (crypt_stat->num_header_bytes_at_front
+ / crypt_stat->extent_size);
- if (view_extent_num < crypt_stat->num_header_extents_at_front) {
+ if (view_extent_num < num_header_extents_at_front) {
/* This is a header extent */
char *page_virt;
flush_dcache_page(page);
if (rc) {
printk(KERN_ERR "%s: Error reading xattr "
- "region; rc = [%d]\n", __FUNCTION__, rc);
+ "region; rc = [%d]\n", __func__, rc);
goto out;
}
} else {
/* This is an encrypted data extent */
loff_t lower_offset =
- ((view_extent_num -
- crypt_stat->num_header_extents_at_front)
- * crypt_stat->extent_size);
+ ((view_extent_num * crypt_stat->extent_size)
+ - crypt_stat->num_header_bytes_at_front);
rc = ecryptfs_read_lower_page_segment(
page, (lower_offset >> PAGE_CACHE_SHIFT),
if (rc) {
printk(KERN_ERR "%s: Error attempting to read "
"extent at offset [%lld] in the lower "
- "file; rc = [%d]\n", __FUNCTION__,
+ "file; rc = [%d]\n", __func__,
lower_offset, rc);
goto out;
}
"the encrypted content from the lower "
"file whilst inserting the metadata "
"from the xattr into the header; rc = "
- "[%d]\n", __FUNCTION__, rc);
+ "[%d]\n", __func__, rc);
goto out;
}
return 0;
}
-/* This function must zero any hole we create */
-static int ecryptfs_prepare_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
+/**
+ * ecryptfs_write_begin
+ * @file: The eCryptfs file
+ * @mapping: The eCryptfs object
+ * @pos: The file offset at which to start writing
+ * @len: Length of the write
+ * @flags: Various flags
+ * @pagep: Pointer to return the page
+ * @fsdata: Pointer to return fs data (unused)
+ *
+ * This function must zero any hole we create
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_write_begin(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
{
- int rc = 0;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ struct page *page;
loff_t prev_page_end_size;
+ int rc = 0;
+
+ page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ return -ENOMEM;
+ *pagep = page;
if (!PageUptodate(page)) {
- rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
- PAGE_CACHE_SIZE,
- page->mapping->host);
- if (rc) {
- printk(KERN_ERR "%s: Error attemping to read lower "
- "page segment; rc = [%d]\n", __FUNCTION__, rc);
- ClearPageUptodate(page);
- goto out;
- } else
+ struct ecryptfs_crypt_stat *crypt_stat =
+ &ecryptfs_inode_to_private(
+ file->f_path.dentry->d_inode)->crypt_stat;
+
+ if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
+ || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
+ rc = ecryptfs_read_lower_page_segment(
+ page, index, 0, PAGE_CACHE_SIZE, mapping->host);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attemping to read "
+ "lower page segment; rc = [%d]\n",
+ __func__, rc);
+ ClearPageUptodate(page);
+ goto out;
+ } else
+ SetPageUptodate(page);
+ } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
+ if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+ rc = ecryptfs_copy_up_encrypted_with_header(
+ page, crypt_stat);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting "
+ "to copy the encrypted content "
+ "from the lower file whilst "
+ "inserting the metadata from "
+ "the xattr into the header; rc "
+ "= [%d]\n", __func__, rc);
+ ClearPageUptodate(page);
+ goto out;
+ }
+ SetPageUptodate(page);
+ } else {
+ rc = ecryptfs_read_lower_page_segment(
+ page, index, 0, PAGE_CACHE_SIZE,
+ mapping->host);
+ if (rc) {
+ printk(KERN_ERR "%s: Error reading "
+ "page; rc = [%d]\n",
+ __func__, rc);
+ ClearPageUptodate(page);
+ goto out;
+ }
+ SetPageUptodate(page);
+ }
+ } else {
+ rc = ecryptfs_decrypt_page(page);
+ if (rc) {
+ printk(KERN_ERR "%s: Error decrypting page "
+ "at index [%ld]; rc = [%d]\n",
+ __func__, page->index, rc);
+ ClearPageUptodate(page);
+ goto out;
+ }
SetPageUptodate(page);
+ }
}
-
- prev_page_end_size = ((loff_t)page->index << PAGE_CACHE_SHIFT);
-
- /*
- * If creating a page or more of holes, zero them out via truncate.
- * Note, this will increase i_size.
- */
- if (page->index != 0) {
+ prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT);
+ /* If creating a page or more of holes, zero them out via truncate.
+ * Note, this will increase i_size. */
+ if (index != 0) {
if (prev_page_end_size > i_size_read(page->mapping->host)) {
rc = ecryptfs_truncate(file->f_path.dentry,
prev_page_end_size);
if (rc) {
- printk(KERN_ERR "Error on attempt to "
+ printk(KERN_ERR "%s: Error on attempt to "
"truncate to (higher) offset [%lld];"
- " rc = [%d]\n", prev_page_end_size, rc);
+ " rc = [%d]\n", __func__,
+ prev_page_end_size, rc);
goto out;
}
}
}
- /*
- * Writing to a new page, and creating a small hole from start of page?
- * Zero it out.
- */
- if ((i_size_read(page->mapping->host) == prev_page_end_size) &&
- (from != 0)) {
+ /* Writing to a new page, and creating a small hole from start
+ * of page? Zero it out. */
+ if ((i_size_read(mapping->host) == prev_page_end_size)
+ && (pos != 0))
zero_user(page, 0, PAGE_CACHE_SIZE);
- }
out:
return rc;
}
*/
static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode)
{
- u64 file_size;
char *file_size_virt;
int rc;
rc = -ENOMEM;
goto out;
}
- file_size = (u64)i_size_read(ecryptfs_inode);
- file_size = cpu_to_be64(file_size);
- memcpy(file_size_virt, &file_size, sizeof(u64));
+ put_unaligned_be64(i_size_read(ecryptfs_inode), file_size_virt);
rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0,
sizeof(u64));
kfree(file_size_virt);
if (rc)
printk(KERN_ERR "%s: Error writing file size to header; "
- "rc = [%d]\n", __FUNCTION__, rc);
+ "rc = [%d]\n", __func__, rc);
out:
return rc;
}
struct dentry *lower_dentry =
ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry;
struct inode *lower_inode = lower_dentry->d_inode;
- u64 file_size;
int rc;
if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) {
xattr_virt, PAGE_CACHE_SIZE);
if (size < 0)
size = 8;
- file_size = (u64)i_size_read(ecryptfs_inode);
- file_size = cpu_to_be64(file_size);
- memcpy(xattr_virt, &file_size, sizeof(u64));
+ put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt);
rc = lower_inode->i_op->setxattr(lower_dentry, ECRYPTFS_XATTR_NAME,
xattr_virt, size, 0);
mutex_unlock(&lower_inode->i_mutex);
struct ecryptfs_crypt_stat *crypt_stat;
crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
+ BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode);
else
}
/**
- * ecryptfs_commit_write
+ * ecryptfs_write_end
* @file: The eCryptfs file object
+ * @mapping: The eCryptfs object
+ * @pos: The file position
+ * @len: The length of the data (unused)
+ * @copied: The amount of data copied
* @page: The eCryptfs page
- * @from: Ignored (we rotate the page IV on each write)
- * @to: Ignored
+ * @fsdata: The fsdata (unused)
*
* 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)
+static int ecryptfs_write_end(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
- loff_t pos;
- struct inode *ecryptfs_inode = page->mapping->host;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+ unsigned to = from + copied;
+ struct inode *ecryptfs_inode = mapping->host;
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat;
int rc;
} 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);
+ "(page w/ index = [0x%.16x], to = [%d])\n", index, to);
+ if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+ rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, 0,
+ to);
+ if (!rc) {
+ rc = copied;
+ fsstack_copy_inode_size(ecryptfs_inode,
+ ecryptfs_inode_to_lower(ecryptfs_inode));
+ }
+ goto out;
+ }
/* Fills in zeros if 'to' goes beyond inode size */
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);
+ "zeros in page with index = [0x%.16x]\n", index);
goto out;
}
rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
- "index [0x%.16x])\n", page->index);
+ "index [0x%.16x])\n", index);
goto out;
}
- pos = (((loff_t)page->index) << PAGE_CACHE_SHIFT) + to;
- if (pos > i_size_read(ecryptfs_inode)) {
- i_size_write(ecryptfs_inode, pos);
+ if (pos + copied > i_size_read(ecryptfs_inode)) {
+ i_size_write(ecryptfs_inode, pos + copied);
ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
"[0x%.16x]\n", i_size_read(ecryptfs_inode));
}
if (rc)
printk(KERN_ERR "Error writing inode size to metadata; "
"rc = [%d]\n", rc);
+ else
+ rc = copied;
out:
+ unlock_page(page);
+ page_cache_release(page);
return rc;
}
struct address_space_operations ecryptfs_aops = {
.writepage = ecryptfs_writepage,
.readpage = ecryptfs_readpage,
- .prepare_write = ecryptfs_prepare_write,
- .commit_write = ecryptfs_commit_write,
+ .write_begin = ecryptfs_write_begin,
+ .write_end = ecryptfs_write_end,
.bmap = ecryptfs_bmap,
};
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff