2.6.24.4

 fs

 ecryptfs

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 32c5711..a985a8f 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -263,52 +263,102 @@ out:
    return 0;
 }
 
-/* This function must zero any hole we create */
+/**
+ * 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(struct file *file, struct page *page,
               unsigned from, unsigned to)
 {
-   int rc = 0;
    loff_t prev_page_end_size;
+   int rc = 0;
 
    if (!PageUptodate(page)) {
-      rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
-                        PAGE_CACHE_SIZE,
-                        page->mapping->host);
-      if (rc) {
-         printk(KERN_ERR "%s: Error attemping to read lower "
-                "page segment; rc = [%d]\n", __FUNCTION__, rc);
-         ClearPageUptodate(page);
-         goto out;
-      } else
+      struct ecryptfs_crypt_stat *crypt_stat =
+         &ecryptfs_inode_to_private(
+            file->f_path.dentry->d_inode)->crypt_stat;
+
+      if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
+          || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
+         rc = ecryptfs_read_lower_page_segment(
+            page, 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);
+      } 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", __FUNCTION__, 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",
+                      __FUNCTION__, 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",
+                   __FUNCTION__, 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 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,
                       prev_page_end_size);
          if (rc) {
-            printk(KERN_ERR "Error on attempt to "
+            printk(KERN_ERR "%s: Error on attempt to "
                    "truncate to (higher) offset [%lld];"
-                   " rc = [%d]\n", prev_page_end_size, rc);
+                   " rc = [%d]\n", __FUNCTION__,
+                   prev_page_end_size, rc);
             goto out;
          }
       }
    }
-   /*
-    * Writing to a new page, and creating a small hole from start of page?
-    * Zero it out.
-    */
-   if ((i_size_read(page->mapping->host) == prev_page_end_size) &&
-       (from != 0)) {
+   /* Writing to a new page, and creating a small hole from start
+    * of page?  Zero it out. */
+   if ((i_size_read(page->mapping->host) == prev_page_end_size)
+       && (from != 0))
       zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
-   }
 out:
    return rc;
 }