linux-ext4 - [PATCH 11/11] fuse4fs: increase attribute timeout in iomap mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <176169818424.1430380.12074181505332544391.stgit@frogsfrogsfrogs>
Date: Tue, 28 Oct 2025 18:16:15 -0700
From: "Darrick J. Wong" <djwong@...nel.org>
To: tytso@....edu
Cc: linux-fsdevel@...r.kernel.org, joannelkoong@...il.com, bernd@...ernd.com,
 neal@...pa.dev, miklos@...redi.hu, linux-ext4@...r.kernel.org
Subject: [PATCH 11/11] fuse4fs: increase attribute timeout in iomap mode

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

In iomap mode, we trust the kernel to cache file attributes, because it
is critical to keep all of the file IO permissions checking in the
kernel as part of keeping all the file IO paths in the kernel.
Therefore, increase the attribute timeout to 30 seconds to reduce the
number of upcalls even further.

Signed-off-by: "Darrick J. Wong" <djwong@...nel.org>
---
 fuse4fs/fuse4fs.c |   15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/fuse4fs/fuse4fs.c b/fuse4fs/fuse4fs.c
index e08e127eb03563..958b3cab83a68d 100644
--- a/fuse4fs/fuse4fs.c
+++ b/fuse4fs/fuse4fs.c
@@ -123,7 +123,8 @@
 #endif
 #endif /* !defined(ENODATA) */

-#define FUSE4FS_ATTR_TIMEOUT	(0.0)
+#define FUSE4FS_IOMAP_ATTR_TIMEOUT	(0.0)
+#define FUSE4FS_ATTR_TIMEOUT		(30.0)

 static inline uint64_t round_up(uint64_t b, unsigned int align)
 {
@@ -2155,8 +2156,14 @@ static int fuse4fs_stat_inode(struct fuse4fs *ff, ext2_ino_t ino,

 	fuse4fs_ino_to_fuse(ff, &entry->ino, ino);
 	entry->generation = inodep->i_generation;
-	entry->attr_timeout = FUSE4FS_ATTR_TIMEOUT;
-	entry->entry_timeout = FUSE4FS_ATTR_TIMEOUT;
+
+	if (fuse4fs_iomap_enabled(ff)) {
+		entry->attr_timeout = FUSE4FS_IOMAP_ATTR_TIMEOUT;
+		entry->entry_timeout = FUSE4FS_IOMAP_ATTR_TIMEOUT;
+	} else {
+		entry->attr_timeout = FUSE4FS_ATTR_TIMEOUT;
+		entry->entry_timeout = FUSE4FS_ATTR_TIMEOUT;
+	}

 	fstat->iflags = 0;

@@ -2389,6 +2396,8 @@ static void op_statx(fuse_req_t req, fuse_ino_t fino, int flags, int mask,
 	fuse4fs_finish(ff, ret);
 	if (ret)
 		fuse_reply_err(req, -ret);
+	else if (fuse4fs_iomap_enabled(ff))
+		fuse_reply_statx(req, 0, &stx, FUSE4FS_IOMAP_ATTR_TIMEOUT);
 	else
 		fuse_reply_statx(req, 0, &stx, FUSE4FS_ATTR_TIMEOUT);
 }