#include <linux/file.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
#include "ecryptfs_kernel.h"
-struct kmem_cache *ecryptfs_lower_page_cache;
-
/**
- * ecryptfs_get1page
+ * ecryptfs_get_locked_page
*
* Get one page from cache or lower f/s, return error otherwise.
*
- * Returns unlocked and up-to-date page (if ok), with increased
+ * Returns locked and up-to-date page (if ok), with increased
* refcnt.
*/
-static struct page *ecryptfs_get1page(struct file *file, int index)
-{
- struct dentry *dentry;
- struct inode *inode;
- struct address_space *mapping;
-
- dentry = file->f_path.dentry;
- inode = dentry->d_inode;
- mapping = inode->i_mapping;
- 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)
+struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index)
{
- 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;
+ struct page *page = read_mapping_page(inode->i_mapping, index, NULL);
+ if (!IS_ERR(page))
+ lock_page(page);
+ return page;
}
/**
*/
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);
+ rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting "
- "page (upper index [0x%.16x])\n", page->index);
+ "page (upper index [0x%.16lx])\n", page->index);
ClearPageUptodate(page);
goto 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)
+static void strip_xattr_flag(char *page_virt,
+ struct ecryptfs_crypt_stat *crypt_stat)
{
- 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;
+ if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+ size_t written;
+
+ crypt_stat->flags &= ~ECRYPTFS_METADATA_IN_XATTR;
+ ecryptfs_write_crypt_stat_flags(page_virt, crypt_stat,
+ &written);
+ crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
}
- 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)
* (big-endian)
* Octet 26: Begin RFC 2440 authentication token packet set
*/
-static void set_header_info(char *page_virt,
- struct ecryptfs_crypt_stat *crypt_stat)
+
+/**
+ * ecryptfs_copy_up_encrypted_with_header
+ * @page: Sort of a ``virtual'' representation of the encrypted lower
+ * file. The actual lower file does not have the metadata in
+ * the header. This is locked.
+ * @crypt_stat: The eCryptfs inode's cryptographic context
+ *
+ * The ``view'' is the version of the file that userspace winds up
+ * seeing, with the header information inserted.
+ */
+static int
+ecryptfs_copy_up_encrypted_with_header(struct page *page,
+ struct ecryptfs_crypt_stat *crypt_stat)
{
- size_t written;
- int save_num_header_extents_at_front =
- crypt_stat->num_header_extents_at_front;
-
- crypt_stat->num_header_extents_at_front = 1;
- ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written);
- crypt_stat->num_header_extents_at_front =
- save_num_header_extents_at_front;
+ loff_t extent_num_in_page = 0;
+ loff_t num_extents_per_page = (PAGE_CACHE_SIZE
+ / crypt_stat->extent_size);
+ int rc = 0;
+
+ while (extent_num_in_page < num_extents_per_page) {
+ 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->metadata_size / crypt_stat->extent_size);
+
+ if (view_extent_num < num_header_extents_at_front) {
+ /* This is a header extent */
+ char *page_virt;
+
+ page_virt = kmap_atomic(page, KM_USER0);
+ memset(page_virt, 0, PAGE_CACHE_SIZE);
+ /* TODO: Support more than one header extent */
+ if (view_extent_num == 0) {
+ size_t written;
+
+ rc = ecryptfs_read_xattr_region(
+ page_virt, page->mapping->host);
+ strip_xattr_flag(page_virt + 16, crypt_stat);
+ ecryptfs_write_header_metadata(page_virt + 20,
+ crypt_stat,
+ &written);
+ }
+ kunmap_atomic(page_virt, KM_USER0);
+ flush_dcache_page(page);
+ if (rc) {
+ printk(KERN_ERR "%s: Error reading xattr "
+ "region; rc = [%d]\n", __func__, rc);
+ goto out;
+ }
+ } else {
+ /* This is an encrypted data extent */
+ loff_t lower_offset =
+ ((view_extent_num * crypt_stat->extent_size)
+ - crypt_stat->metadata_size);
+
+ rc = ecryptfs_read_lower_page_segment(
+ page, (lower_offset >> PAGE_CACHE_SHIFT),
+ (lower_offset & ~PAGE_CACHE_MASK),
+ crypt_stat->extent_size, page->mapping->host);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to read "
+ "extent at offset [%lld] in the lower "
+ "file; rc = [%d]\n", __func__,
+ lower_offset, rc);
+ goto out;
+ }
+ }
+ extent_num_in_page++;
+ }
+out:
+ return rc;
}
/**
* ecryptfs_readpage
- * @file: This is an ecryptfs file
- * @page: ecryptfs associated page to stick the read data into
+ * @file: An eCryptfs file
+ * @page: Page from eCryptfs inode mapping into which to stick the read data
*
* Read in a page, decrypting if necessary.
*
*/
static int ecryptfs_readpage(struct file *file, struct page *page)
{
+ struct ecryptfs_crypt_stat *crypt_stat =
+ &ecryptfs_inode_to_private(page->mapping->host)->crypt_stat;
int rc = 0;
- struct ecryptfs_crypt_stat *crypt_stat;
- BUG_ON(!(file && file->f_path.dentry && file->f_path.dentry->d_inode));
- crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)
- ->crypt_stat;
- if (!crypt_stat
- || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
- || (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;
- }
+ if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+ rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
+ PAGE_CACHE_SIZE,
+ page->mapping->host);
} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
- int num_pages_in_header_region =
- (crypt_stat->header_extent_size
- / PAGE_CACHE_SIZE);
-
- if (page->index < num_pages_in_header_region) {
- char *page_virt;
-
- page_virt = kmap_atomic(page, KM_USER0);
- memset(page_virt, 0, PAGE_CACHE_SIZE);
- if (page->index == 0) {
- rc = ecryptfs_read_xattr_region(
- page_virt, file->f_path.dentry);
- set_header_info(page_virt, crypt_stat);
- }
- kunmap_atomic(page_virt, KM_USER0);
- flush_dcache_page(page);
- if (rc) {
- printk(KERN_ERR "Error reading xattr "
- "region\n");
- goto out;
- }
- } else {
- rc = ecryptfs_do_readpage(
- file, page,
- (page->index
- - num_pages_in_header_region));
- if (rc) {
- printk(KERN_ERR "Error reading page; "
- "rc = [%d]\n", rc);
- goto out;
- }
+ 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);
+ goto out;
}
+
} else {
- rc = ecryptfs_do_readpage(file, page, page->index);
+ rc = ecryptfs_read_lower_page_segment(
+ page, page->index, 0, PAGE_CACHE_SIZE,
+ page->mapping->host);
if (rc) {
printk(KERN_ERR "Error reading page; rc = "
"[%d]\n", rc);
}
}
} else {
- rc = ecryptfs_decrypt_page(file, page);
+ rc = ecryptfs_decrypt_page(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",
+ else
+ SetPageUptodate(page);
+ ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n",
page->index);
unlock_page(page);
return rc;
end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE;
if (to > end_byte_in_page)
end_byte_in_page = to;
- zero_user_page(page, end_byte_in_page,
- PAGE_CACHE_SIZE - end_byte_in_page, KM_USER0);
+ zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE);
out:
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().
+ * 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_prepare_write_no_truncate(struct file *file, struct page *page,
- unsigned from, unsigned to)
+static int ecryptfs_write_begin(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
{
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ struct page *page;
+ loff_t prev_page_end_size;
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)
-{
- int rc = 0;
+ page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ return -ENOMEM;
+ *pagep = 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);
- if (page->index != 0) {
- loff_t end_of_prev_pg_pos = page_offset(page) - 1;
+ prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT);
+ if (!PageUptodate(page)) {
+ struct ecryptfs_crypt_stat *crypt_stat =
+ &ecryptfs_inode_to_private(mapping->host)->crypt_stat;
- if (end_of_prev_pg_pos > i_size_read(page->mapping->host)) {
+ if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+ 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 {
+ if (prev_page_end_size
+ >= i_size_read(page->mapping->host)) {
+ zero_user(page, 0, PAGE_CACHE_SIZE);
+ } 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);
+ }
+ }
+ /* 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,
- end_of_prev_pg_pos);
+ 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", end_of_prev_pg_pos, rc);
+ " rc = [%d]\n", __func__,
+ prev_page_end_size, rc);
goto out;
}
}
- if (end_of_prev_pg_pos + 1 > i_size_read(page->mapping->host))
- zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
- }
-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);
+ /* 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 void ecryptfs_release_lower_page(struct page *lower_page)
-{
- unlock_page(lower_page);
- page_cache_release(lower_page);
-}
-
/**
* ecryptfs_write_inode_size_to_header
*
*
* Returns zero on success; non-zero on error.
*/
-static 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 inode *ecryptfs_inode)
{
- int rc = 0;
- struct page *header_page;
- char *header_virt;
- const struct address_space_operations *lower_a_ops;
- u64 file_size;
-
- header_page = grab_cache_page(lower_inode->i_mapping, 0);
- if (!header_page) {
- ecryptfs_printk(KERN_ERR, "grab_cache_page for "
- "lower_page_index 0 failed\n");
- rc = -EINVAL;
- goto out;
- }
- lower_a_ops = lower_inode->i_mapping->a_ops;
- rc = lower_a_ops->prepare_write(lower_file, header_page, 0, 8);
- if (rc) {
- ecryptfs_release_lower_page(header_page);
+ char *file_size_virt;
+ int rc;
+
+ file_size_virt = kmalloc(sizeof(u64), GFP_KERNEL);
+ if (!file_size_virt) {
+ rc = -ENOMEM;
goto out;
}
- 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);
- header_virt = kmap_atomic(header_page, KM_USER0);
- memcpy(header_virt, &file_size, sizeof(u64));
- kunmap_atomic(header_virt, KM_USER0);
- flush_dcache_page(header_page);
- rc = lower_a_ops->commit_write(lower_file, header_page, 0, 8);
+ 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 < 0)
- ecryptfs_printk(KERN_ERR, "Error commiting header page "
- "write\n");
- ecryptfs_release_lower_page(header_page);
- lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
- mark_inode_dirty_sync(inode);
+ printk(KERN_ERR "%s: Error writing file size to header; "
+ "rc = [%d]\n", __func__, rc);
+ else
+ rc = 0;
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)
+struct kmem_cache *ecryptfs_xattr_cache;
+
+static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
{
ssize_t size;
void *xattr_virt;
- struct dentry *lower_dentry;
- u64 file_size;
+ struct dentry *lower_dentry =
+ ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry;
+ struct inode *lower_inode = lower_dentry->d_inode;
int rc;
+ if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) {
+ printk(KERN_WARNING
+ "No support for setting xattr in lower filesystem\n");
+ rc = -ENOSYS;
+ goto out;
+ }
xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL);
if (!xattr_virt) {
printk(KERN_ERR "Out of memory whilst attempting to write "
rc = -ENOMEM;
goto out;
}
- lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
- if (!lower_dentry->d_inode->i_op->getxattr ||
- !lower_dentry->d_inode->i_op->setxattr) {
- 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);
+ mutex_lock(&lower_inode->i_mutex);
+ size = lower_inode->i_op->getxattr(lower_dentry, ECRYPTFS_XATTR_NAME,
+ xattr_virt, PAGE_CACHE_SIZE);
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);
+ 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);
if (rc)
printk(KERN_ERR "Error whilst attempting to write inode size "
"to lower file xattr; rc = [%d]\n", rc);
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)
+int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode)
{
struct ecryptfs_crypt_stat *crypt_stat;
- crypt_stat = &ecryptfs_inode_to_private(inode)->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(lower_inode, inode,
- ecryptfs_dentry,
- lower_i_mutex_held);
+ return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode);
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,
- 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;
+ return ecryptfs_write_inode_size_to_header(ecryptfs_inode);
}
/**
- * 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;
-}
-
-struct kmem_cache *ecryptfs_xattr_cache;
-
-/**
- * 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)
{
- 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;
+ 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(ecryptfs_inode)->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_path.dentry->d_inode)
- ->crypt_stat;
- if (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);
- crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE);
- } 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%.16lx], 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%.16lx]\n", index);
goto out;
}
- ctx.page = page;
- ctx.mode = ECRYPTFS_PREPARE_COMMIT_MODE;
- ctx.param.lower_file = lower_file;
- rc = ecryptfs_encrypt_page(&ctx);
+ rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
- "index [0x%.16x])\n", page->index);
+ "index [0x%.16lx])\n", index);
goto out;
}
- inode->i_blocks = lower_inode->i_blocks;
- pos = page_offset(page) + to;
- if (pos > i_size_read(inode)) {
- i_size_write(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(inode));
+ "[0x%.16llx]\n",
+ (unsigned long long)i_size_read(ecryptfs_inode));
}
- rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
- inode, file->f_dentry,
- ECRYPTFS_LOWER_I_MUTEX_HELD);
+ rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
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:
- if (rc < 0)
- ClearPageUptodate(page);
else
- SetPageUptodate(page);
- mutex_unlock(&lower_inode->i_mutex);
- 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;
- }
- if ((rc = ecryptfs_prepare_write_no_truncate(file, tmp_page, start,
- (start + num_zeros)))) {
- 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);
+ rc = copied;
out:
+ unlock_page(page);
+ page_cache_release(page);
return rc;
}
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;
- }
- if (lower_page->mapping->a_ops->sync_page)
- 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 = {
+const 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,
- .sync_page = ecryptfs_sync_page,
};
Code Review / linux-2.6.git / blobdiff