[PATCH v3 00/10] netfs, cachefiles: Miscellaneous fixes
From: David Howells
Date: Thu Aug 27 2026 - 05:44:41 EST
Hi Christian,
Here are some miscellaneous fixes for netfslib and one for cachefiles, if
you could pick them up?
The first six are all in unbuffered/DIO write:
(1) Fix an uninitialised return value from netfs_unbuffered_write().
(2) Fix the normal error return, preferring partial transfer size over
request error over immediate error (e.g. EINTR).
(3) Fix the async error return, preferring partial transfer size over
error.
(4) Fix the update of i_size on partial transfer ending in an error.
(5) Fix a subrequest leak in an error path.
(6) Fix the code to handle subrequest allocation failure.
Then there's:
(7) Fix synchronisation issues with using a progressive rolling buffer for
readahead by fetching everything into it upfront so that the issues
don't arise. Dropping the refs so acquired is deferred until after
I/O is begun.
(8) Change the marking of folios to be copied to the cache to be done
whilst subreqs are being issued rather than at the time they're
collected. Whilst this is not strictly a fix, it means that the
collector thread doesn't need to try and keep track of that, which
means that delayed progress reporting will not be a problem in patch
(9).
(9) Fix read progress reporting to avoid 64-bit tearing on a 32-bit
machine. This has been modified from the previous submission as part
of a different series to take account of a sashiko reported issue[1].
(10) Fix a potential UAF/KASAN warning reported by sashiko[1] in cachefiles
in which the coherency data buffer is cast to a __be64* and
dereferenced in a tracepoint - even though it might not be at least
that large (or aligned).
The patches can also be found here:
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=netfs-fixes
Thanks,
David
Changes
=======
ver #3)
- Fixed a number of issues reported by Sashiko[3]:
- Fixed netfs_unbuffered_write() to return -ENOMEM to async writes too.
- Added a patch to preload the entire readahead folio collection up front
to avoid producer-consumer synchronisation issues.
- Added a patch to premark buffered read folios with whether or not
they're going to require caching so that the read-progress fix works
correctly.
ver #2)
- Imported a patch to add subreq alloc failure handling in unbuffered/DIO
write.
- Fixed a number of issues reported by Sashiko[2]:
- Added four patches to fix bugs in unbuffered/DIO write.
- Added a patch to fix readahead rolling buffer issues.
- Fixed the cachefiles xattr stuff to use max() not min() when
allocating.
- Fixed the cachefiles trace comment with regard to alignment.
- Fixed netfs_read_set_unlock_at() to use folioq_count(), not
folio_nr_slots().
[1] https://sashiko.dev/#/patchset/20260810144746.574036-1-dhowells%40redhat.com
[2] https://sashiko.dev/#/patchset/20260824120224.504575-1-dhowells%40redhat.com
[3] https://sashiko.dev/#/patchset/20260825132045.1000787-1-dhowells%40redhat.com
David Howells (8):
netfs: Fix unbuffered/DIO write partial transfer error return
netfs: Fix error vs transferred passed to ->ki_complete()
netfs: Fix i_size update for partial transfer
netfs: Fix subreq ref leak
netfs: Fix readahead synchronisation issues by loading all folios
upfront
netfs: Mark folios with COPY_TO_CACHE whilst issuing subreqs
netfs: Fix read progress reporting
cachefiles: Fix potential UAF/KASAN warning
Edward Adam Davis (1):
netfs: break unbuffered write when netfs_alloc_subrequest() fails
Karl Mehltretter (1):
netfs: Fix uninitialized return value in netfs_unbuffered_write()
fs/cachefiles/xattr.c | 16 +--
fs/netfs/buffered_read.c | 165 ++++++++++++++++++++++--------
fs/netfs/direct_write.c | 31 ++++--
fs/netfs/internal.h | 2 +
fs/netfs/misc.c | 19 ++++
fs/netfs/objects.c | 32 +++---
fs/netfs/read_collect.c | 103 ++++++++++++-------
fs/netfs/read_pgpriv2.c | 13 ++-
fs/netfs/read_retry.c | 7 ++
fs/netfs/read_single.c | 2 +
fs/netfs/rolling_buffer.c | 81 +++++++++------
fs/netfs/write_issue.c | 2 +
include/linux/netfs.h | 5 +-
include/linux/rolling_buffer.h | 6 +-
include/trace/events/cachefiles.h | 19 +++-
include/trace/events/netfs.h | 30 +++++-
16 files changed, 381 insertions(+), 152 deletions(-)