Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 07 Mar 2019 23:17:27 +0000
From:      bugzilla-noreply@freebsd.org
To:        bugs@FreeBSD.org
Subject:   [Bug 236378] [FUSE] fuse must set FUSE_WRITE_CACHE when writing from the page cache
Message-ID:  <bug-236378-227@https.bugs.freebsd.org/bugzilla/>

next in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D236378

            Bug ID: 236378
           Summary: [FUSE] fuse must set FUSE_WRITE_CACHE when writing
                    from the page cache
           Product: Base System
           Version: CURRENT
          Hardware: Any
                OS: Any
            Status: New
          Severity: Affects Many People
          Priority: ---
         Component: kern
          Assignee: bugs@FreeBSD.org
          Reporter: asomers@FreeBSD.org

FUSE operations all record the pid, uid, and gid of the requesting process.=
=20
Many FUSE filesystem daemons use that to authenticate accesses.  Ideally, t=
hey
would only do it on FUSE_OPEN.  But may daemons are internally stateless, w=
hich
requires them to authenticate operations on every operation, including
FUSE_WRITE.

However, writes that come from the page cache (such as when a fuse-backed f=
ile
is mmap()ed or when using the writeback caching strategy introduced in prot=
ocol
7.23) cannot set these fields correctly, because multiple processes may have
written to the same file.  For such cases, FUSE_WRITE defines the
FUSE_WRITE_CACHE flag, which indicates to the filesystem daemon that these
fields are not valid.

fuse(4) must set this flag when issueing writes from the cache.

--=20
You are receiving this mail because:
You are the assignee for the bug.=



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-236378-227>