WSL2-Linux-Kernel/io_uring
David Hildenbrand fc4f4be9b5 mm/nommu: factor out check for NOMMU shared mappings into is_nommu_shared_mapping()
Patch series "mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings".

Trying to reduce the confusion around VM_SHARED and VM_MAYSHARE first
requires !CONFIG_MMU to stop using VM_MAYSHARE for MAP_PRIVATE mappings. 
CONFIG_MMU only sets VM_MAYSHARE for MAP_SHARED mappings.

This paves the way for further VM_MAYSHARE and VM_SHARED cleanups: for
example, renaming VM_MAYSHARED to VM_MAP_SHARED to make it cleaner what is
actually means.

Let's first get the weird case out of the way and not use VM_MAYSHARE in
MAP_PRIVATE mappings, using a new VM_MAYOVERLAY flag instead.


This patch (of 3):

We want to stop using VM_MAYSHARE in private mappings to pave the way for
clarifying the semantics of VM_MAYSHARE vs.  VM_SHARED and reduce the
confusion.  While CONFIG_MMU uses VM_MAYSHARE to represent MAP_SHARED,
!CONFIG_MMU also sets VM_MAYSHARE for selected R/O private file mappings
that are an effective overlay of a file mapping.

Let's factor out all relevant VM_MAYSHARE checks in !CONFIG_MMU code into
is_nommu_shared_mapping() first.

Note that whenever VM_SHARED is set, VM_MAYSHARE must be set as well
(unless there is a serious BUG).  So there is not need to test for
VM_SHARED manually.

No functional change intended.

Link: https://lkml.kernel.org/r/20230102160856.500584-1-david@redhat.com
Link: https://lkml.kernel.org/r/20230102160856.500584-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:56 -08:00
..
Makefile io_uring: add zc notification infrastructure 2022-07-24 18:41:06 -06:00
advise.c io_uring: make io_kiocb_to_cmd() typesafe 2022-08-12 17:01:00 -06:00
advise.h io_uring: split out fadvise/madvise operations 2022-07-24 18:39:11 -06:00
alloc_cache.h io_uring: impose max limit on apoll cache 2022-07-24 18:39:17 -06:00
cancel.c io_uring/cancel: re-grab ctx mutex after finishing wait 2022-12-21 13:31:40 -07:00
cancel.h io_uring: add sync cancelation API through io_uring_register() 2022-07-24 18:39:15 -06:00
epoll.c io_uring: make io_kiocb_to_cmd() typesafe 2022-08-12 17:01:00 -06:00
epoll.h io_uring: move epoll handler to its own file 2022-07-24 18:39:11 -06:00
fdinfo.c io_uring/fdinfo: include locked hash table in fdinfo output 2023-01-10 10:24:52 -07:00
fdinfo.h io_uring: move fdinfo helpers to its own file 2022-07-24 18:39:12 -06:00
filetable.c io_uring/filetable: fix file reference underflow 2022-11-25 06:54:46 -07:00
filetable.h io_uring: kill hot path fixed file bitmap debug checks 2022-10-16 17:07:53 -06:00
fs.c io_uring: make io_kiocb_to_cmd() typesafe 2022-08-12 17:01:00 -06:00
fs.h io_uring: split out filesystem related operations 2022-07-24 18:39:11 -06:00
io-wq.c io_uring/io-wq: only free worker if it was allocated for creation 2023-01-08 10:39:17 -07:00
io-wq.h io_uring: move list helpers to a separate file 2022-07-24 18:39:15 -06:00
io_uring.c mm/nommu: factor out check for NOMMU shared mappings into is_nommu_shared_mapping() 2023-01-18 17:12:56 -08:00
io_uring.h io_uring: lockdep annotate CQ locking 2023-01-03 19:05:41 -07:00
kbuf.c io_uring: don't use complete_post in kbuf 2022-11-25 06:11:15 -07:00
kbuf.h io_uring: allow buffer recycling in READV 2022-09-21 10:30:43 -06:00
msg_ring.c io_uring/msg_ring: flag target ring as having task_work, if needed 2022-12-08 09:36:02 -07:00
msg_ring.h io_uring: get rid of double locking 2022-12-07 06:47:13 -07:00
net.c io_uring/net: fix cleanup after recycle 2022-12-19 08:28:28 -07:00
net.h io_uring/net: zerocopy sendmsg 2022-09-21 13:15:02 -06:00
nop.c io_uring: kill extra io_uring_types.h includes 2022-07-24 18:39:14 -06:00
nop.h io_uring: move nop into its own file 2022-07-24 18:39:11 -06:00
notif.c io_uring/net: move mm accounting to a slower path 2022-11-21 07:38:31 -07:00
notif.h io_uring: move zc reporting from the hot path 2022-11-21 07:38:31 -07:00
opdef.c io_uring: get rid of double locking 2022-12-07 06:47:13 -07:00
opdef.h io_uring: dont remove file from msg_ring reqs 2022-12-07 06:47:13 -07:00
openclose.c io_uring: make io_kiocb_to_cmd() typesafe 2022-08-12 17:01:00 -06:00
openclose.h io_uring: split out fixed file installation and removal 2022-07-24 18:39:16 -06:00
poll.c io_uring/poll: attempt request issue after racy poll wakeup 2023-01-12 10:35:51 -07:00
poll.h io_uring: add abstraction around apoll cache 2022-07-24 18:39:17 -06:00
refs.h io_uring: make io_uring_types.h public 2022-07-24 18:39:14 -06:00
rsrc.c io_uring: use tw for putting rsrc 2022-12-07 06:47:13 -07:00
rsrc.h io_uring: use tw for putting rsrc 2022-12-07 06:47:13 -07:00
rw.c io_uring: lock overflowing for IOPOLL 2023-01-13 07:32:46 -07:00
rw.h io_uring/rw: don't lose partial IO result on fail 2022-09-21 13:15:02 -06:00
slist.h io_uring: move list helpers to a separate file 2022-07-24 18:39:15 -06:00
splice.c io_uring: make io_kiocb_to_cmd() typesafe 2022-08-12 17:01:00 -06:00
splice.h io_uring: split out splice related operations 2022-07-24 18:39:11 -06:00
sqpoll.c audit, io_uring, io-wq: Fix memory leak in io_sq_thread() and io_wqe_worker() 2022-08-04 08:33:54 -06:00
sqpoll.h io_uring: move SQPOLL related handling into its own file 2022-07-24 18:39:12 -06:00
statx.c io_uring: make io_kiocb_to_cmd() typesafe 2022-08-12 17:01:00 -06:00
statx.h io_uring: move statx handling to its own file 2022-07-24 18:39:11 -06:00
sync.c io_uring: make io_kiocb_to_cmd() typesafe 2022-08-12 17:01:00 -06:00
sync.h io_uring: split out fs related sync/fallocate functions 2022-07-24 18:39:11 -06:00
tctx.c io_uring: remove io_register_submitter 2022-10-07 12:25:30 -06:00
tctx.h io_uring: simplify __io_uring_add_tctx_node 2022-10-07 12:25:30 -06:00
timeout.c io_uring: ease timeout flush locking requirements 2022-12-14 08:53:35 -07:00
timeout.h io_uring: remove unused return from io_disarm_next 2022-09-21 13:15:01 -06:00
uring_cmd.c io_uring: iopoll protect complete_post 2022-11-23 10:45:31 -07:00
uring_cmd.h io_uring: move uring_cmd handling to its own file 2022-07-24 18:39:11 -06:00
xattr.c acl: conver higher-level helpers to rely on mnt_idmap 2022-10-31 17:48:12 +01:00
xattr.h io_uring: move xattr related opcodes to its own file 2022-07-24 18:39:11 -06:00