From: Lokesh Gidra <lokeshgidra@google.com>
To: akpm@linux-foundation.org
Cc: lokeshgidra@google.com, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
selinux@vger.kernel.org, surenb@google.com,
kernel-team@android.com, aarcange@redhat.com, peterx@redhat.com,
david@redhat.com, axelrasmussen@google.com, bgeffon@google.com,
willy@infradead.org, jannh@google.com, kaleshsingh@google.com,
ngeoffray@google.com, timmurray@google.com, rppt@kernel.org
Subject: [PATCH 1/3] userfaultfd: move userfaultfd_ctx struct to header file
Date: Fri, 26 Jan 2024 10:26:45 -0800 [thread overview]
Message-ID: <20240126182647.2748949-1-lokeshgidra@google.com> (raw)
Moving the struct to userfaultfd_k.h to be accessible from
mm/userfaultfd.c. There are no other changes in the struct.
This is required to prepare for using per-vma locks in userfaultfd
operations.
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
---
fs/userfaultfd.c | 39 -----------------------------------
include/linux/userfaultfd_k.h | 39 +++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+), 39 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 959551ff9a95..af5ebaad2f1d 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -50,45 +50,6 @@ static struct ctl_table vm_userfaultfd_table[] = {
static struct kmem_cache *userfaultfd_ctx_cachep __ro_after_init;
-/*
- * Start with fault_pending_wqh and fault_wqh so they're more likely
- * to be in the same cacheline.
- *
- * Locking order:
- * fd_wqh.lock
- * fault_pending_wqh.lock
- * fault_wqh.lock
- * event_wqh.lock
- *
- * To avoid deadlocks, IRQs must be disabled when taking any of the above locks,
- * since fd_wqh.lock is taken by aio_poll() while it's holding a lock that's
- * also taken in IRQ context.
- */
-struct userfaultfd_ctx {
- /* waitqueue head for the pending (i.e. not read) userfaults */
- wait_queue_head_t fault_pending_wqh;
- /* waitqueue head for the userfaults */
- wait_queue_head_t fault_wqh;
- /* waitqueue head for the pseudo fd to wakeup poll/read */
- wait_queue_head_t fd_wqh;
- /* waitqueue head for events */
- wait_queue_head_t event_wqh;
- /* a refile sequence protected by fault_pending_wqh lock */
- seqcount_spinlock_t refile_seq;
- /* pseudo fd refcounting */
- refcount_t refcount;
- /* userfaultfd syscall flags */
- unsigned int flags;
- /* features requested from the userspace */
- unsigned int features;
- /* released */
- bool released;
- /* memory mappings are changing because of non-cooperative event */
- atomic_t mmap_changing;
- /* mm with one ore more vmas attached to this userfaultfd_ctx */
- struct mm_struct *mm;
-};
-
struct userfaultfd_fork_ctx {
struct userfaultfd_ctx *orig;
struct userfaultfd_ctx *new;
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index e4056547fbe6..691d928ee864 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -36,6 +36,45 @@
#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
+/*
+ * Start with fault_pending_wqh and fault_wqh so they're more likely
+ * to be in the same cacheline.
+ *
+ * Locking order:
+ * fd_wqh.lock
+ * fault_pending_wqh.lock
+ * fault_wqh.lock
+ * event_wqh.lock
+ *
+ * To avoid deadlocks, IRQs must be disabled when taking any of the above locks,
+ * since fd_wqh.lock is taken by aio_poll() while it's holding a lock that's
+ * also taken in IRQ context.
+ */
+struct userfaultfd_ctx {
+ /* waitqueue head for the pending (i.e. not read) userfaults */
+ wait_queue_head_t fault_pending_wqh;
+ /* waitqueue head for the userfaults */
+ wait_queue_head_t fault_wqh;
+ /* waitqueue head for the pseudo fd to wakeup poll/read */
+ wait_queue_head_t fd_wqh;
+ /* waitqueue head for events */
+ wait_queue_head_t event_wqh;
+ /* a refile sequence protected by fault_pending_wqh lock */
+ seqcount_spinlock_t refile_seq;
+ /* pseudo fd refcounting */
+ refcount_t refcount;
+ /* userfaultfd syscall flags */
+ unsigned int flags;
+ /* features requested from the userspace */
+ unsigned int features;
+ /* released */
+ bool released;
+ /* memory mappings are changing because of non-cooperative event */
+ atomic_t mmap_changing;
+ /* mm with one ore more vmas attached to this userfaultfd_ctx */
+ struct mm_struct *mm;
+};
+
extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
/* A combined operation mode + behavior flags. */
--
2.43.0.429.g432eaa2c6b-goog
next reply other threads:[~2024-01-26 18:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-26 18:26 Lokesh Gidra [this message]
2024-01-26 18:26 ` [PATCH 2/3] userfaultfd: protect mmap_changing with rw_sem in userfaulfd_ctx Lokesh Gidra
2024-01-26 18:26 ` [PATCH 3/3] userfaultfd: use per-vma locks in userfaultfd operations Lokesh Gidra
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