linux-ext4 - [PATCHSET v6 4/5] libfuse: cache iomap mappings for even better file IO performance

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 for Android: free password hash cracker in your pocket

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

Message-ID: <176169814570.1428599.1070273812934230095.stgit@frogsfrogsfrogs>
Date: Tue, 28 Oct 2025 17:40:47 -0700
From: "Darrick J. Wong" <djwong@...nel.org>
To: djwong@...nel.org, bschubert@....com
Cc: linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org,
 bernd@...ernd.com, miklos@...redi.hu, joannelkoong@...il.com, neal@...pa.dev
Subject: [PATCHSET v6 4/5] libfuse: cache iomap mappings for even better file
 IO performance

Hi all,

This series improves the performance (and correctness for some
filesystems) by adding the ability to cache iomap mappings in the
kernel.  For filesystems that can change mapping states during pagecache
writeback (e.g. unwritten extent conversion) this is absolutely
necessary to deal with races with writes to the pagecache because
writeback does not take i_rwsem.  For everyone else, it simply
eliminates roundtrips to userspace.

If you're going to start using this code, I strongly recommend pulling
from my git trees, which are linked below.

With a bit of luck, this should all go splendidly.
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=fuse-iomap-cache
---
Commits in this patchset:
 * libfuse: enable iomap cache management for lowlevel fuse
 * libfuse: add upper-level iomap cache management
 * libfuse: enable iomap
---
 include/fuse.h          |   31 +++++++++++++++++++
 include/fuse_common.h   |   12 ++++++++
 include/fuse_kernel.h   |   26 ++++++++++++++++
 include/fuse_lowlevel.h |   41 ++++++++++++++++++++++++++
 lib/fuse.c              |   30 +++++++++++++++++++
 lib/fuse_lowlevel.c     |   75 ++++++++++++++++++++++++++++++++++++++++++++++-
 lib/fuse_versionscript  |    4 +++
 7 files changed, 217 insertions(+), 2 deletions(-)