switch ecryptfs_write() to struct inode *, kill on-stack fake files

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ecryptfs/ecryptfs_kernel.h

@@ -731,8 +731,7 @@ int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
 int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
 				      struct page *page_for_lower,
 				      size_t offset_in_page, size_t size);
-int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
+int ecryptfs_write(struct inode *inode, char *data, loff_t offset, size_t size);
-		   size_t size);
 int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
 			struct inode *ecryptfs_inode);
 int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs,

fs/ecryptfs/inode.c

@@ -142,19 +142,10 @@ out:
 static int grow_file(struct dentry *ecryptfs_dentry)
 {
 	struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
-	struct file fake_file;
-	struct ecryptfs_file_info tmp_file_info;
 	char zero_virt[] = { 0x00 };
 	int rc = 0;
 
-	memset(&fake_file, 0, sizeof(fake_file));
+	rc = ecryptfs_write(ecryptfs_inode, zero_virt, 0, 1);
-	fake_file.f_path.dentry = ecryptfs_dentry;
-	memset(&tmp_file_info, 0, sizeof(tmp_file_info));
-	ecryptfs_set_file_private(&fake_file, &tmp_file_info);
-	ecryptfs_set_file_lower(
-		&fake_file,
-		ecryptfs_inode_to_private(ecryptfs_inode)->lower_file);
-	rc = ecryptfs_write(&fake_file, zero_virt, 0, 1);
 	i_size_write(ecryptfs_inode, 0);
 	rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
 	ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
@@ -784,8 +775,6 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 {
 	int rc = 0;
 	struct inode *inode = dentry->d_inode;
-	struct dentry *lower_dentry;
-	struct file fake_ecryptfs_file;
 	struct ecryptfs_crypt_stat *crypt_stat;
 	loff_t i_size = i_size_read(inode);
 	loff_t lower_size_before_truncate;
@@ -796,23 +785,6 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 		goto out;
 	}
 	crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
-	/* Set up a fake ecryptfs file, this is used to interface with
-	 * the file in the underlying filesystem so that the
-	 * truncation has an effect there as well. */
-	memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
-	fake_ecryptfs_file.f_path.dentry = dentry;
-	/* Released at out_free: label */
-	ecryptfs_set_file_private(&fake_ecryptfs_file,
-				  kmem_cache_alloc(ecryptfs_file_info_cache,
-						   GFP_KERNEL));
-	if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
-		rc = -ENOMEM;
-		goto out;
-	}
-	lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	ecryptfs_set_file_lower(
-		&fake_ecryptfs_file,
-		ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
 	/* Switch on growing or shrinking file */
 	if (ia->ia_size > i_size) {
 		char zero[] = { 0x00 };
@@ -822,7 +794,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 		 * this triggers code that will fill in 0's throughout
 		 * the intermediate portion of the previous end of the
 		 * file and the new and of the file */
-		rc = ecryptfs_write(&fake_ecryptfs_file, zero,
+		rc = ecryptfs_write(inode, zero,
 				    (ia->ia_size - 1), 1);
 	} else { /* ia->ia_size < i_size_read(inode) */
 		/* We're chopping off all the pages down to the page
@@ -835,10 +807,10 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 		if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
 			rc = vmtruncate(inode, ia->ia_size);
 			if (rc)
-				goto out_free;
+				goto out;
 			lower_ia->ia_size = ia->ia_size;
 			lower_ia->ia_valid |= ATTR_SIZE;
-			goto out_free;
+			goto out;
 		}
 		if (num_zeros) {
 			char *zeros_virt;
@@ -846,16 +818,16 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 			zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
 			if (!zeros_virt) {
 				rc = -ENOMEM;
-				goto out_free;
+				goto out;
 			}
-			rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
+			rc = ecryptfs_write(inode, zeros_virt,
 					    ia->ia_size, num_zeros);
 			kfree(zeros_virt);
 			if (rc) {
 				printk(KERN_ERR "Error attempting to zero out "
 				       "the remainder of the end page on "
 				       "reducing truncate; rc = [%d]\n", rc);
-				goto out_free;
+				goto out;
 			}
 		}
 		vmtruncate(inode, ia->ia_size);
@@ -864,7 +836,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 			printk(KERN_ERR	"Problem with "
 			       "ecryptfs_write_inode_size_to_metadata; "
 			       "rc = [%d]\n", rc);
-			goto out_free;
+			goto out;
 		}
 		/* We are reducing the size of the ecryptfs file, and need to
 		 * know if we need to reduce the size of the lower file. */
@@ -878,10 +850,6 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 		} else
 			lower_ia->ia_valid &= ~ATTR_SIZE;
 	}
-out_free:
-	if (ecryptfs_file_to_private(&fake_ecryptfs_file))
-		kmem_cache_free(ecryptfs_file_info_cache,
-				ecryptfs_file_to_private(&fake_ecryptfs_file));
 out:
 	return rc;
 }

fs/ecryptfs/read_write.c

@@ -93,7 +93,7 @@ int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
 
 /**
  * ecryptfs_write
- * @ecryptfs_file: The eCryptfs file into which to write
+ * @ecryptfs_inode: The eCryptfs file into which to write
  * @data: Virtual address where data to write is located
  * @offset: Offset in the eCryptfs file at which to begin writing the
  *          data from @data
@@ -109,12 +109,11 @@ int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
  *
  * Returns zero on success; non-zero otherwise
  */
-int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
+int ecryptfs_write(struct inode *ecryptfs_inode, char *data, loff_t offset,
 		   size_t size)
 {
 	struct page *ecryptfs_page;
 	struct ecryptfs_crypt_stat *crypt_stat;
-	struct inode *ecryptfs_inode = ecryptfs_file->f_dentry->d_inode;
 	char *ecryptfs_page_virt;
 	loff_t ecryptfs_file_size = i_size_read(ecryptfs_inode);
 	loff_t data_offset = 0;