From: Ard Biesheuvel <ardb@kernel.org>
Date: Thu, 6 Mar 2025 13:08:27 +0000 (+0100)
Subject: efivarfs: Revert "allow creation of zero length files"
X-Git-Tag: v6.15-rc1~114^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b6b227e36b5ad878260f5a3a1838f2d79d5e68e9;p=thirdparty%2Fkernel%2Flinux.git

efivarfs: Revert "allow creation of zero length files"

As agreed with the fwupd/LVFS maintainer, this reverts commit
fc20737d8b85691ecabab3739ed7d06c9b7bc00f again for the v6.15 cycle,
leaving them sufficient time to roll out a fix for the issue that the
reverted commit works around.

Link: https://lore.kernel.org/all/63837c36eceaf8cf2af7933dccca54ff4dd9f30d.camel@HansenPartnership.com/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---

diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index c294a8fc566da..cb1b6d0c34545 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -57,11 +57,10 @@ static ssize_t efivarfs_file_write(struct file *file,
 
 	if (bytes == -ENOENT) {
 		/*
-		 * FIXME: temporary workaround for fwupdate, signal
-		 * failed write with a 1 to keep created but not
-		 * written files
+		 * zero size signals to release that the write deleted
+		 * the variable
 		 */
-		i_size_write(inode, 1);
+		i_size_write(inode, 0);
 	} else {
 		i_size_write(inode, datasize + sizeof(attributes));
 		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
@@ -125,8 +124,7 @@ static int efivarfs_file_release(struct inode *inode, struct file *file)
 	struct efivar_entry *var = inode->i_private;
 
 	inode_lock(inode);
-	/* FIXME: temporary work around for fwupdate */
-	var->removed = (--var->open_count == 0 && i_size_read(inode) == 1);
+	var->removed = (--var->open_count == 0 && i_size_read(inode) == 0);
 	inode_unlock(inode);
 
 	if (var->removed)