Re: [PATCH] netfs: Fix early read unlock of page with EOF in middle

[Christian Brauner]

On Sat, 20 Dec 2025 12:31:40 +0000, David Howells wrote:
> The read result collection for buffered reads seems to run ahead of the
> completion of subrequests under some circumstances, as can be seen in the
> following log snippet:
> 
>     9p_client_res: client 18446612686390831168 response P9_TREAD tag  0 err 0
>     ...
>     netfs_sreq: R=00001b55[1] DOWN TERM  f=192 s=0 5fb2/5fb2 s=5 e=0
>     ...
>     netfs_collect_folio: R=00001b55 ix=00004 r=4000-5000 t=4000/5fb2
>     netfs_folio: i=157f3 ix=00004-00004 read-done
>     netfs_folio: i=157f3 ix=00004-00004 read-unlock
>     netfs_collect_folio: R=00001b55 ix=00005 r=5000-5fb2 t=5000/5fb2
>     netfs_folio: i=157f3 ix=00005-00005 read-done
>     netfs_folio: i=157f3 ix=00005-00005 read-unlock
>     ...
>     netfs_collect_stream: R=00001b55[0:] cto=5fb2 frn=ffffffff
>     netfs_collect_state: R=00001b55 col=5fb2 cln=6000 n=c
>     netfs_collect_stream: R=00001b55[0:] cto=5fb2 frn=ffffffff
>     netfs_collect_state: R=00001b55 col=5fb2 cln=6000 n=8
>     ...
>     netfs_sreq: R=00001b55[2] ZERO SUBMT f=000 s=5fb2 0/4e s=0 e=0
>     netfs_sreq: R=00001b55[2] ZERO TERM  f=102 s=5fb2 4e/4e s=5 e=0
> 
> [...]

Applied to the vfs.fixes branch of the vfs/vfs.git tree.
Patches in the vfs.fixes branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.fixes

[1/1] netfs: Fix early read unlock of page with EOF in middle
      https://git.kernel.org/vfs/vfs/c/570ad253a345