[PATCH 1/3] uffd: Tossing bits around

From: Pavel Emelyanov
Date: Wed Mar 18 2015 - 15:35:06 EST


Reformat the existing code a bit to make it easier for
further patching.

Signed-off-by: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
---
fs/userfaultfd.c | 37 ++++++++++++++++++++++++++++---------
1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index b4c7f25..6c9a2d6 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -61,6 +61,23 @@ struct userfaultfd_wake_range {
unsigned long len;
};

+static const struct file_operations userfaultfd_fops;
+
+static struct userfaultfd_ctx *userfaultfd_ctx_alloc(void)
+{
+ struct userfaultfd_ctx *ctx;
+
+ ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+ if (ctx) {
+ atomic_set(&ctx->refcount, 1);
+ init_waitqueue_head(&ctx->fault_wqh);
+ init_waitqueue_head(&ctx->fd_wqh);
+ ctx->released = false;
+ }
+
+ return ctx;
+}
+
static int userfaultfd_wake_function(wait_queue_t *wq, unsigned mode,
int wake_flags, void *key)
{
@@ -307,15 +324,15 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
return 0;
}

-static inline unsigned int find_userfault(struct userfaultfd_ctx *ctx,
+static inline unsigned int do_find_userfault(wait_queue_head_t *wqh,
struct userfaultfd_wait_queue **uwq)
{
wait_queue_t *wq;
struct userfaultfd_wait_queue *_uwq;
unsigned int ret = 0;

- spin_lock(&ctx->fault_wqh.lock);
- list_for_each_entry(wq, &ctx->fault_wqh.task_list, task_list) {
+ spin_lock(&wqh->lock);
+ list_for_each_entry(wq, &wqh->task_list, task_list) {
_uwq = container_of(wq, struct userfaultfd_wait_queue, wq);
if (_uwq->pending) {
ret = POLLIN;
@@ -324,11 +341,17 @@ static inline unsigned int find_userfault(struct userfaultfd_ctx *ctx,
break;
}
}
- spin_unlock(&ctx->fault_wqh.lock);
+ spin_unlock(&wqh->lock);

return ret;
}

+static inline unsigned int find_userfault(struct userfaultfd_ctx *ctx,
+ struct userfaultfd_wait_queue **uwq)
+{
+ return do_find_userfault(&ctx->fault_wqh, uwq);
+}
+
static unsigned int userfaultfd_poll(struct file *file, poll_table *wait)
{
struct userfaultfd_ctx *ctx = file->private_data;
@@ -1080,16 +1103,12 @@ static struct file *userfaultfd_file_create(int flags)
goto out;

file = ERR_PTR(-ENOMEM);
- ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+ ctx = userfaultfd_ctx_alloc();
if (!ctx)
goto out;

- atomic_set(&ctx->refcount, 1);
- init_waitqueue_head(&ctx->fault_wqh);
- init_waitqueue_head(&ctx->fd_wqh);
ctx->flags = flags;
ctx->state = UFFD_STATE_WAIT_API;
- ctx->released = false;
ctx->mm = current->mm;
/* prevent the mm struct to be freed */
atomic_inc(&ctx->mm->mm_count);
--
1.8.4.2


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