linux-ext4 - [PATCH 04/10] fuse2fs: better debugging for file mode updates

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Message-ID: <175279461792.716436.14623391892076767727.stgit@frogsfrogsfrogs>
Date: Thu, 17 Jul 2025 16:46:25 -0700
From: "Darrick J. Wong" <djwong@...nel.org>
To: tytso@....edu
Cc: joannelkoong@...il.com, miklos@...redi.hu, John@...ves.net,
 linux-fsdevel@...r.kernel.org, bernd@...ernd.com, linux-ext4@...r.kernel.org,
 neal@...pa.dev
Subject: [PATCH 04/10] fuse2fs: better debugging for file mode updates

From: Darrick J. Wong <djwong@...nel.org>

Improve the tracing of a chmod operation so that we can debug file mode
updates.

Signed-off-by: "Darrick J. Wong" <djwong@...nel.org>
---
 misc/fuse2fs.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index e580622d39b1d1..f2cb44a4e53b4c 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -2964,12 +2964,13 @@ static int op_chmod(const char *path, mode_t mode
 #endif
 			)
 {
+	struct ext2_inode_large inode;
 	struct fuse_context *ctxt = fuse_get_context();
 	struct fuse2fs *ff = (struct fuse2fs *)ctxt->private_data;
 	ext2_filsys fs;
 	errcode_t err;
 	ext2_ino_t ino;
-	struct ext2_inode_large inode;
+	mode_t new_mode;
 	int ret = 0;

 	FUSE2FS_CHECK_CONTEXT(ff);
@@ -3008,11 +3009,12 @@ static int op_chmod(const char *path, mode_t mode
 			mode &= ~S_ISGID;
 	}

-	inode.i_mode &= ~0xFFF;
-	inode.i_mode |= mode & 0xFFF;
+	new_mode = (inode.i_mode & ~0xFFF) | (mode & 0xFFF);

-	dbg_printf(ff, "%s: path=%s new_mode=0%o ino=%d\n", __func__,
-		   path, inode.i_mode, ino);
+	dbg_printf(ff, "%s: path=%s old_mode=0%o new_mode=0%o ino=%d\n",
+		   __func__, path, inode.i_mode, new_mode, ino);
+
+	inode.i_mode = new_mode;

 	ret = update_ctime(fs, ino, &inode);
 	if (ret)