ecryptfs: discard ecryptfsd registration messages in miscdev
[safe/jmp/linux-2.6] / fs / ecryptfs / mmap.c
index 60e635e..2b6fe1e 100644 (file)
 #include <linux/scatterlist.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.
  */
-struct page *ecryptfs_get1page(struct file *file, loff_t index)
+struct page *ecryptfs_get_locked_page(struct file *file, loff_t index)
 {
        struct dentry *dentry;
        struct inode *inode;
        struct address_space *mapping;
+       struct page *page;
 
        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)
-{
-       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;
+       page = read_mapping_page(mapping, index, (void *)file);
+       if (!IS_ERR(page))
+               lock_page(page);
+       return page;
 }
 
 /**
@@ -187,58 +82,6 @@ out:
 }
 
 /**
- * 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)
  *     Octets 8-15:       eCryptfs special marker
@@ -257,19 +100,90 @@ static void set_header_info(char *page_virt,
                            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;
+}
+
+/**
+ * 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)
+{
+       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->num_header_bytes_at_front
+                        / 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) {
+                               rc = ecryptfs_read_xattr_region(
+                                       page_virt, page->mapping->host);
+                               set_header_info(page_virt, crypt_stat);
+                       }
+                       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->num_header_bytes_at_front);
+
+                       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.
  *
@@ -277,59 +191,35 @@ static void set_header_info(char *page_virt,
  */
 static int ecryptfs_readpage(struct file *file, struct page *page)
 {
+       struct ecryptfs_crypt_stat *crypt_stat =
+               &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->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;
-               }
+               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->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, page->mapping->host);
-                                       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);
@@ -344,10 +234,11 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
                        goto out;
                }
        }
-       SetPageUptodate(page);
 out:
        if (rc)
                ClearPageUptodate(page);
+       else
+               SetPageUptodate(page);
        ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n",
                        page->index);
        unlock_page(page);
@@ -367,87 +258,111 @@ static int fill_zeros_to_end_of_page(struct page *page, unsigned int to)
        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_prepare_write
+ * @file: The eCryptfs file
+ * @page: The eCryptfs page
+ * @from: The start byte from which we will write
+ * @to: The end byte to which we will write
+ *
+ * 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)
-{
-       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)
 {
+       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);
-       if (page->index != 0) {
-               loff_t end_of_prev_pg_pos = page_offset(page) - 1;
+       if (!PageUptodate(page)) {
+               struct ecryptfs_crypt_stat *crypt_stat =
+                       &ecryptfs_inode_to_private(
+                               file->f_path.dentry->d_inode)->crypt_stat;
 
-               if (end_of_prev_pg_pos > i_size_read(page->mapping->host)) {
+               if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
+                   || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
+                       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",
+                                      __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, page->index, 0, PAGE_CACHE_SIZE,
+                                       page->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) {
+               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(page->mapping->host) == prev_page_end_size)
+           && (from != 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
  *
@@ -474,7 +389,7 @@ static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode)
        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;
 }
@@ -534,90 +449,6 @@ int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode)
                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
@@ -633,18 +464,11 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
                                 unsigned from, unsigned to)
 {
        loff_t pos;
-       struct inode *inode;
-       struct inode *lower_inode;
-       struct file *lower_file;
-       struct ecryptfs_crypt_stat *crypt_stat;
+       struct inode *ecryptfs_inode = page->mapping->host;
+       struct ecryptfs_crypt_stat *crypt_stat =
+               &ecryptfs_inode_to_private(file->f_path.dentry->d_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);
@@ -654,6 +478,7 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
        ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page"
                        "(page w/ index = [0x%.16x], to = [%d])\n", page->index,
                        to);
+       /* 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 "
@@ -667,72 +492,16 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
                                "index [0x%.16x])\n", page->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);
+       pos = (((loff_t)page->index) << PAGE_CACHE_SHIFT) + to;
+       if (pos > i_size_read(ecryptfs_inode)) {
+               i_size_write(ecryptfs_inode, pos);
                ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
-                               "[0x%.16x]\n", i_size_read(inode));
+                               "[0x%.16x]\n", i_size_read(ecryptfs_inode));
        }
-       rc = ecryptfs_write_inode_size_to_metadata(inode);
+       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;
-       }
-       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;
 }
@@ -751,34 +520,10 @@ static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t 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;
-       }
-       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 = {
        .writepage = ecryptfs_writepage,
        .readpage = ecryptfs_readpage,
        .prepare_write = ecryptfs_prepare_write,
        .commit_write = ecryptfs_commit_write,
        .bmap = ecryptfs_bmap,
-       .sync_page = ecryptfs_sync_page,
 };