Attachment 296513 Details for Bug 435610 – Mike's patch, backported for RHEL5.2

[patch] Mike's patch, backported for RHEL5.2

ecryptfs-prepare.patch (text/plain), 4.00 KB, created by Eric Sandeen on 2008-03-02 15:04:17 UTC

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Creator: Eric Sandeen

Created: 2008-03-02 15:04:17 UTC

Size: 4.00 KB

patch

obsolete

>Index: linux-2.6.18.x86_64/fs/ecryptfs/mmap.c
>===================================================================
>--- linux-2.6.18.x86_64.orig/fs/ecryptfs/mmap.c
>+++ linux-2.6.18.x86_64/fs/ecryptfs/mmap.c
>@@ -263,52 +263,103 @@ 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_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_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))
> 		memclear_highpage_flush(page, 0, PAGE_CACHE_SIZE);
>-	}
> out:
> 	return rc;
> }
>

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Attachments on bug 435610: 296513