2.6.24

 fs

 ecryptfs

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index fd3f94d..32c5711 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -37,130 +37,27 @@
 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 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;
 }
 
 /**
@@ -171,13 +68,9 @@ out:
  */
 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);
@@ -191,58 +84,6 @@ 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
@@ -271,9 +112,77 @@ static void set_header_info(char *page_virt,
 }
 
 /**
+ * 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);
+
+      if (view_extent_num < crypt_stat->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", __FUNCTION__, 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);
+
+         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", __FUNCTION__,
+                   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.
  *
@@ -281,59 +190,35 @@ 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->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", __FUNCTION__, 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);
@@ -341,17 +226,18 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
          }
       }
    } 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);
+   else
+      SetPageUptodate(page);
    ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n",
          page->index);
    unlock_page(page);
@@ -377,83 +263,56 @@ 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().
- */
-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;
-}
-
+/* This function must zero any hole we create */
 static int ecryptfs_prepare_write(struct file *file, struct page *page,
               unsigned from, unsigned to)
 {
    int rc = 0;
+   loff_t prev_page_end_size;
 
-   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)) {
+      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
+         SetPageUptodate(page);
+   }
+
+   prev_page_end_size = ((loff_t)page->index << PAGE_CACHE_SHIFT);
 
-      if (end_of_prev_pg_pos > i_size_read(page->mapping->host)) {
+   /*
+    * 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 "
                    "truncate to (higher) offset [%lld];"
-                   " rc = [%d]\n", end_of_prev_pg_pos, rc);
+                   " rc = [%d]\n", 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;
+   /*
+    * 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(page, 0, PAGE_CACHE_SIZE, KM_USER0);
    }
-   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, int page_locked)
-{
-   if (page_locked)
-      unlock_page(lower_page);
-   page_cache_release(lower_page);
-}
-
 /**
  * ecryptfs_write_inode_size_to_header
  *
@@ -461,67 +320,48 @@ void ecryptfs_release_lower_page(struct page *lower_page, int page_locked)
  *
  * 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;
+   char *file_size_virt;
+   int rc;
 
-retry:
-   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) {
-      if (rc == AOP_TRUNCATED_PAGE) {
-         ecryptfs_release_lower_page(header_page, 0);
-         goto retry;
-      } else
-         ecryptfs_release_lower_page(header_page, 1);
+   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 = (u64)i_size_read(ecryptfs_inode);
    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);
-   if (rc < 0)
-      ecryptfs_printk(KERN_ERR, "Error commiting header page "
-            "write\n");
-   if (rc == AOP_TRUNCATED_PAGE) {
-      ecryptfs_release_lower_page(header_page, 0);
-      goto retry;
-   } else
-      ecryptfs_release_lower_page(header_page, 1);
-   lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
-   mark_inode_dirty_sync(inode);
+   memcpy(file_size_virt, &file_size, sizeof(u64));
+   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);
 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;
+   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) {
+      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 "
@@ -529,35 +369,17 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode,
       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 = (u64)i_size_read(ecryptfs_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);
+   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);
@@ -566,121 +388,17 @@ out:
    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;
    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;
-
-retry:
-   *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) {
-      if (rc == AOP_TRUNCATED_PAGE) {
-         ecryptfs_release_lower_page(*lower_page, 0);
-         goto retry;
-      } else {
-         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, 1);
-         (*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 page_locked = 1;
-   int rc = 0;
-
-   rc = lower_inode->i_mapping->a_ops->commit_write(
-      lower_file, lower_page, byte_offset, region_size);
-   if (rc == AOP_TRUNCATED_PAGE)
-      page_locked = 0;
-   if (rc < 0) {
-      ecryptfs_printk(KERN_ERR,
-            "Error committing write; rc = [%d]\n", rc);
-   } else
-      rc = 0;
-   ecryptfs_release_lower_page(lower_page, page_locked);
-   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;
+      return ecryptfs_write_inode_size_to_header(ecryptfs_inode);
 }
 
-struct kmem_cache *ecryptfs_xattr_cache;
-
 /**
  * ecryptfs_commit_write
  * @file: The eCryptfs file object
@@ -695,20 +413,12 @@ struct kmem_cache *ecryptfs_xattr_cache;
 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;
+   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);
@@ -718,6 +428,7 @@ 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 "
@@ -725,82 +436,22 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
             page->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);
       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(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);
 out:
    return rc;
 }
@@ -819,34 +470,10 @@ 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,
 };