return rc;
}
-static void
-ecryptfs_extent_to_lwr_pg_idx_and_offset(unsigned long *lower_page_idx,
- int *byte_offset,
- struct ecryptfs_crypt_stat *crypt_stat,
- unsigned long extent_num)
-{
- unsigned long lower_extent_num;
- int extents_occupied_by_headers_at_front;
- int bytes_occupied_by_headers_at_front;
- int extent_offset;
- int extents_per_page;
-
- bytes_occupied_by_headers_at_front =
- (crypt_stat->extent_size
- * crypt_stat->num_header_extents_at_front);
- extents_occupied_by_headers_at_front =
- ( bytes_occupied_by_headers_at_front
- / crypt_stat->extent_size );
- lower_extent_num = extents_occupied_by_headers_at_front + extent_num;
- extents_per_page = PAGE_CACHE_SIZE / crypt_stat->extent_size;
- (*lower_page_idx) = lower_extent_num / extents_per_page;
- extent_offset = lower_extent_num % extents_per_page;
- (*byte_offset) = extent_offset * crypt_stat->extent_size;
- ecryptfs_printk(KERN_DEBUG, " * crypt_stat->extent_size = "
- "[%d]\n", crypt_stat->extent_size);
- ecryptfs_printk(KERN_DEBUG, " * crypt_stat->"
- "num_header_extents_at_front = [%d]\n",
- crypt_stat->num_header_extents_at_front);
- ecryptfs_printk(KERN_DEBUG, " * extents_occupied_by_headers_at_"
- "front = [%d]\n", extents_occupied_by_headers_at_front);
- ecryptfs_printk(KERN_DEBUG, " * lower_extent_num = [0x%.16x]\n",
- lower_extent_num);
- ecryptfs_printk(KERN_DEBUG, " * extents_per_page = [%d]\n",
- extents_per_page);
- ecryptfs_printk(KERN_DEBUG, " * (*lower_page_idx) = [0x%.16x]\n",
- (*lower_page_idx));
- ecryptfs_printk(KERN_DEBUG, " * extent_offset = [%d]\n",
- extent_offset);
- ecryptfs_printk(KERN_DEBUG, " * (*byte_offset) = [%d]\n",
- (*byte_offset));
-}
-
-static int ecryptfs_write_out_page(struct ecryptfs_page_crypt_context *ctx,
- struct page *lower_page,
- struct inode *lower_inode,
- int byte_offset_in_page, int bytes_to_write)
-{
- int rc = 0;
-
- if (ctx->mode == ECRYPTFS_PREPARE_COMMIT_MODE) {
- rc = ecryptfs_commit_lower_page(lower_page, lower_inode,
- ctx->param.lower_file,
- byte_offset_in_page,
- bytes_to_write);
- if (rc) {
- ecryptfs_printk(KERN_ERR, "Error calling lower "
- "commit; rc = [%d]\n", rc);
- goto out;
- }
- } else {
- rc = ecryptfs_writepage_and_release_lower_page(lower_page,
- lower_inode,
- ctx->param.wbc);
- if (rc) {
- ecryptfs_printk(KERN_ERR, "Error calling lower "
- "writepage(); rc = [%d]\n", rc);
- goto out;
- }
- }
-out:
- return rc;
-}
-
-static int ecryptfs_read_in_page(struct ecryptfs_page_crypt_context *ctx,
- struct page **lower_page,
- struct inode *lower_inode,
- unsigned long lower_page_idx,
- int byte_offset_in_page)
-{
- int rc = 0;
-
- if (ctx->mode == ECRYPTFS_PREPARE_COMMIT_MODE) {
- /* TODO: Limit this to only the data extents that are
- * needed */
- rc = ecryptfs_get_lower_page(lower_page, lower_inode,
- ctx->param.lower_file,
- lower_page_idx,
- byte_offset_in_page,
- (PAGE_CACHE_SIZE
- - byte_offset_in_page));
- if (rc) {
- ecryptfs_printk(
- KERN_ERR, "Error attempting to grab, map, "
- "and prepare_write lower page with index "
- "[0x%.16x]; rc = [%d]\n", lower_page_idx, rc);
- goto out;
- }
- } else {
- *lower_page = grab_cache_page(lower_inode->i_mapping,
- lower_page_idx);
- if (!(*lower_page)) {
- rc = -EINVAL;
- ecryptfs_printk(
- KERN_ERR, "Error attempting to grab and map "
- "lower page with index [0x%.16x]; rc = [%d]\n",
- lower_page_idx, rc);
- goto out;
- }
- }
-out:
- return rc;
-}
-
/**
* ecryptfs_lower_offset_for_extent
*
return rc;
}
-/**
- * ecryptfs_read_header_region
- * @data: The virtual address to write header region data into
- * @dentry: The lower dentry
- * @mnt: The lower VFS mount
- *
- * Returns zero on success; non-zero otherwise
- */
-static int ecryptfs_read_header_region(char *data, struct dentry *dentry,
- struct vfsmount *mnt)
-{
- struct file *lower_file;
- mm_segment_t oldfs;
- int rc;
-
- rc = ecryptfs_open_lower_file(&lower_file, dentry, mnt, O_RDONLY);
- if (rc) {
- printk(KERN_ERR
- "Error opening lower_file to read header region\n");
- goto out;
- }
- lower_file->f_pos = 0;
- oldfs = get_fs();
- set_fs(get_ds());
- rc = lower_file->f_op->read(lower_file, (char __user *)data,
- ECRYPTFS_DEFAULT_EXTENT_SIZE, &lower_file->f_pos);
- set_fs(oldfs);
- rc = ecryptfs_close_lower_file(lower_file);
- if (rc) {
- printk(KERN_ERR "Error closing lower_file\n");
- goto out;
- }
- rc = 0;
-out:
- return rc;
-}
-
int ecryptfs_read_and_validate_header_region(char *data,
struct inode *ecryptfs_inode)
{
return read_mapping_page(mapping, index, (void *)file);
}
-/**
- * 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_path.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 = ecryptfs_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, "ecryptfs_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 = ecryptfs_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, "ecryptfs_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 = ecryptfs_write_zeros(file, index, 0, PAGE_CACHE_SIZE);
- if (rc) {
- ecryptfs_printk(KERN_ERR, "ecryptfs_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 = ecryptfs_write_zeros(file, index, 0, (new_end_pos_in_page + 1));
- if (rc) {
- ecryptfs_printk(KERN_ERR, "ecryptfs_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
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_path.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;
- }
- page_data = kmap_atomic(page, KM_USER0);
- lower_page_data = kmap_atomic(lower_page, KM_USER1);
- memcpy(page_data, lower_page_data, PAGE_CACHE_SIZE);
- kunmap_atomic(lower_page_data, KM_USER1);
- kunmap_atomic(page_data, KM_USER0);
- flush_dcache_page(page);
- rc = 0;
-out:
- if (likely(lower_page))
- page_cache_release(lower_page);
- if (rc == 0)
- SetPageUptodate(page);
- else
- ClearPageUptodate(page);
- return rc;
-}
/**
* Header Extent:
* Octets 0-7: Unencrypted file size (big-endian)
return 0;
}
-/**
- * eCryptfs does not currently support holes. When writing after a
- * seek past the end of the file, eCryptfs fills in 0's through to the
- * current location. The code to fill in the 0's to all the
- * intermediate pages calls ecryptfs_prepare_write_no_truncate().
- */
-static int
-ecryptfs_prepare_write_no_truncate(struct file *file, struct page *page,
- unsigned from, unsigned to)
-{
- int rc = 0;
-
- 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;
-}
-
static int ecryptfs_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
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_release_lower_page(struct page *lower_page)
-{
- unlock_page(lower_page);
- page_cache_release(lower_page);
-}
-
/**
* ecryptfs_write_inode_size_to_header
*
return ecryptfs_write_inode_size_to_header(ecryptfs_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,
- int region_bytes)
-{
- int rc = 0;
-
- *lower_page = grab_cache_page(lower_inode->i_mapping, lower_page_index);
- if (!(*lower_page)) {
- rc = -EINVAL;
- ecryptfs_printk(KERN_ERR, "Error attempting to grab "
- "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);
- ecryptfs_release_lower_page(*lower_page);
- (*lower_page) = NULL;
- }
-out:
- 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_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;
-}
-
/**
* ecryptfs_commit_write
* @file: The eCryptfs file object
return rc;
}
-/**
- * ecryptfs_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
- */
-int
-ecryptfs_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;
- }
- rc = ecryptfs_prepare_write_no_truncate(file, tmp_page, start,
- (start + num_zeros));
- if (rc) {
- ecryptfs_printk(KERN_ERR, "Error preparing to write zero's "
- "to page at index [0x%.16x]\n",
- index);
- page_cache_release(tmp_page);
- goto out;
- }
- zero_user_page(tmp_page, start, num_zeros, KM_USER0);
- 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);
- page_cache_release(tmp_page);
- goto out;
- }
- rc = 0;
- page_cache_release(tmp_page);
-out:
- return rc;
-}
-
static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
{
int rc = 0;
projects / linux-2.6 / commitdiff