eCryptfs: replace encrypt, decrypt, and inode size write

Replace page encryption and decryption routines and inode size write routine
with versions that utilize the read_write.c functions.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ecryptfs/ecryptfs_kernel.h

@@ -552,13 +552,7 @@ void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
 void ecryptfs_destroy_mount_crypt_stat(
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
 int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);
-#define ECRYPTFS_LOWER_I_MUTEX_NOT_HELD 0
-#define ECRYPTFS_LOWER_I_MUTEX_HELD 1
-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 *ecryptefs_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,
@@ -574,8 +568,8 @@ int ecryptfs_do_readpage(struct file *file, struct page *page,
 int ecryptfs_writepage_and_release_lower_page(struct page *lower_page,
 					      struct inode *lower_inode,
 					      struct writeback_control *wbc);
-int ecryptfs_encrypt_page(struct ecryptfs_page_crypt_context *ctx);
-int ecryptfs_decrypt_page(struct file *file, struct page *page);
+int ecryptfs_encrypt_page(struct page *page);
+int ecryptfs_decrypt_page(struct page *page);
 int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
 			    struct file *lower_file);
 int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry,
@@ -655,6 +649,8 @@ int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
 				      char *sig);
 int ecryptfs_write_zeros(struct file *file, pgoff_t index, int start,
 			 int num_zeros);
+void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
+				      struct ecryptfs_crypt_stat *crypt_stat);
 int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
 			 loff_t offset, size_t size);
 int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,

fs/ecryptfs/inode.c

@@ -168,9 +168,7 @@ static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file,
 		goto out;
 	}
 	i_size_write(inode, 0);
-	rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
-			inode, ecryptfs_dentry,
-			ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
+	rc = ecryptfs_write_inode_size_to_metadata(inode);
 	ecryptfs_inode_to_private(inode)->crypt_stat.flags |= ECRYPTFS_NEW_FILE;
 out:
 	return rc;
@@ -798,9 +796,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 			goto out_fput;
 		}
 		i_size_write(inode, new_length);
-		rc = ecryptfs_write_inode_size_to_metadata(
-			lower_file, lower_dentry->d_inode, inode, dentry,
-			ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
+		rc = ecryptfs_write_inode_size_to_metadata(inode);
 		if (rc) {
 			printk(KERN_ERR	"Problem with "
 			       "ecryptfs_write_inode_size_to_metadata; "
@@ -829,9 +825,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 			}
 		}
 		vmtruncate(inode, new_length);
-		rc = ecryptfs_write_inode_size_to_metadata(
-			lower_file, lower_dentry->d_inode, inode, dentry,
-			ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
+		rc = ecryptfs_write_inode_size_to_metadata(inode);
 		if (rc) {
 			printk(KERN_ERR	"Problem with "
 			       "ecryptfs_write_inode_size_to_metadata; "

fs/ecryptfs/mmap.c

@@ -171,13 +171,9 @@ int ecryptfs_fill_zeros(struct file *file, loff_t new_length)
  */
 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);
@@ -341,7 +337,7 @@ 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);
@@ -459,58 +455,48 @@ static void ecryptfs_release_lower_page(struct page *lower_page)
  *
  * 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;
 
-	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);
+	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");
-	ecryptfs_release_lower_page(header_page);
-	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 "
@@ -518,35 +504,17 @@ 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,
+	rc = lower_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);
+	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);
@@ -555,24 +523,15 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode,
 	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);
+		return ecryptfs_write_inode_size_to_header(ecryptfs_inode);
 }
 
 int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
@@ -659,8 +618,6 @@ int ecryptfs_copy_page_to_lower(struct page *page, struct inode *lower_inode,
 	return rc;
 }
 
-struct kmem_cache *ecryptfs_xattr_cache;
-
 /**
  * ecryptfs_commit_write
  * @file: The eCryptfs file object
@@ -675,7 +632,6 @@ 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;
@@ -705,10 +661,7 @@ 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);
@@ -721,9 +674,7 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
 		ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
 				"[0x%.16x]\n", i_size_read(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(inode);
 	if (rc)
 		printk(KERN_ERR "Error writing inode size to metadata; "
 		       "rc = [%d]\n", rc);

fs/ecryptfs/read_write.c

@@ -154,8 +154,8 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
 			/* Read in the page from the lower
 			 * into the eCryptfs inode page cache,
 			 * decrypting */
-			if ((rc = ecryptfs_decrypt_page(NULL, /* placeholder for git-bisect */
-							ecryptfs_page))) {
+			rc = ecryptfs_decrypt_page(ecryptfs_page);
+			if (rc) {
 				printk(KERN_ERR "%s: Error decrypting "
 				       "page; rc = [%d]\n",
 				       __FUNCTION__, rc);
@@ -178,7 +178,7 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
 		}
 		kunmap_atomic(ecryptfs_page_virt, KM_USER0);
 		flush_dcache_page(ecryptfs_page);
-		rc = ecryptfs_encrypt_page(NULL /* placeholder for git-bisect */);
+		rc = ecryptfs_encrypt_page(ecryptfs_page);
 		if (rc) {
 			printk(KERN_ERR "%s: Error encrypting "
 			       "page; rc = [%d]\n", __FUNCTION__, rc);
@@ -190,8 +190,8 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
 	}
 	if ((offset + size) > ecryptfs_file_size) {
 		i_size_write(ecryptfs_file->f_dentry->d_inode, (offset + size));
-		rc = ecryptfs_write_inode_size_to_metadata(NULL, NULL, NULL,
-							   NULL, 0); /* placeholders for git-bisect */
+		rc = ecryptfs_write_inode_size_to_metadata(
+			ecryptfs_file->f_dentry->d_inode);
 		if (rc) {
 			printk(KERN_ERR	"Problem with "
 			       "ecryptfs_write_inode_size_to_metadata; "
@@ -338,7 +338,7 @@ int ecryptfs_read(char *data, loff_t offset, size_t size,
 			       ecryptfs_page_idx, rc);
 			goto out;
 		}
-		rc = ecryptfs_decrypt_page(NULL /* placeholder for git-bisect */, ecryptfs_page);
+		rc = ecryptfs_decrypt_page(ecryptfs_page);
 		if (rc) {
 			printk(KERN_ERR "%s: Error decrypting "
 			       "page; rc = [%d]\n", __FUNCTION__, rc);