linux-ext4 - [PATCH 3/3] fuse2fs: catch positive errnos coming from libext2fs

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Message-ID: <174966018106.3972888.12154557537002504919.stgit@frogsfrogsfrogs>
Date: Wed, 11 Jun 2025 09:44:17 -0700
From: "Darrick J. Wong" <djwong@...nel.org>
To: tytso@....edu
Cc: linux-ext4@...r.kernel.org, linux-ext4@...r.kernel.org
Subject: [PATCH 3/3] fuse2fs: catch positive errnos coming from libext2fs

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

Something in libext2fs is returning EOVERFLOW (positive) to us.  We need
to pass negative errnos back to the fuse driver, so perform this
translation.

Cc: <linux-ext4@...r.kernel.org> # v1.43
Fixes: 81cbf1ef4f5dab ("misc: add fuse2fs, a FUSE server for e2fsprogs")
Signed-off-by: "Darrick J. Wong" <djwong@...nel.org>
---
 misc/fuse2fs.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index cc023065727fd5..2bf7413bebb70c 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -4633,8 +4633,18 @@ static int __translate_error(ext2_filsys fs, ext2_ino_t ino, errcode_t err,
 	int is_err = 0;

 	/* Translate ext2 error to unix error code */
-	if (err < EXT2_ET_BASE)
+	if (err < EXT2_ET_BASE) {
+		if (err > 0) {
+			/*
+			 * Apparently libext2fs can throw positive errno
+			 * numbers at us.  We need to return negative errnos
+			 * to the fuse driver.
+			 */
+			is_err = 1;
+			ret = -err;
+		}
 		goto no_translation;
+	}
 	switch (err) {
 	case EXT2_ET_NO_MEMORY:
 	case EXT2_ET_TDB_ERR_OOM: