aio: add kiocb_cancel()

Minor refactoring, to get rid of some duplicated code

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/aio.c b/fs/aio.c
index 8b43d6b..dbfcd67 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -220,6 +220,29 @@ static inline void put_ioctx(struct kioctx *kioctx)
                __put_ioctx(kioctx);
 }
 
+static int kiocb_cancel(struct kioctx *ctx, struct kiocb *kiocb,
+                       struct io_event *res)
+{
+       int (*cancel)(struct kiocb *, struct io_event *);
+       int ret = -EINVAL;
+
+       cancel = kiocb->ki_cancel;
+       kiocbSetCancelled(kiocb);
+       if (cancel) {
+               kiocb->ki_users++;
+               spin_unlock_irq(&ctx->ctx_lock);
+
+               memset(res, 0, sizeof(*res));
+               res->obj = (u64)(unsigned long)kiocb->ki_obj.user;
+               res->data = kiocb->ki_user_data;
+               ret = cancel(kiocb, res);
+
+               spin_lock_irq(&ctx->ctx_lock);
+       }
+
+       return ret;
+}
+
 /* ioctx_alloc
  *     Allocates and initializes an ioctx.  Returns an ERR_PTR if it failed.
  */
@@ -290,25 +313,19 @@ out_freectx:
  */
 static void kill_ctx(struct kioctx *ctx)
 {
-       int (*cancel)(struct kiocb *, struct io_event *);
        struct task_struct *tsk = current;
        DECLARE_WAITQUEUE(wait, tsk);
        struct io_event res;
+       struct kiocb *req;
 
        spin_lock_irq(&ctx->ctx_lock);
        ctx->dead = 1;
        while (!list_empty(&ctx->active_reqs)) {
-               struct list_head *pos = ctx->active_reqs.next;
-               struct kiocb *iocb = list_kiocb(pos);
-               list_del_init(&iocb->ki_list);
-               cancel = iocb->ki_cancel;
-               kiocbSetCancelled(iocb);
-               if (cancel) {
-                       iocb->ki_users++;
-                       spin_unlock_irq(&ctx->ctx_lock);
-                       cancel(iocb, &res);
-                       spin_lock_irq(&ctx->ctx_lock);
-               }
+               req = list_first_entry(&ctx->active_reqs,
+                                       struct kiocb, ki_list);
+
+               list_del_init(&req->ki_list);
+               kiocb_cancel(ctx, req, &res);
        }
 
        if (!ctx->reqs_active)
@@ -1416,7 +1433,7 @@ static struct kiocb *lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb,
 SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
                struct io_event __user *, result)
 {
-       int (*cancel)(struct kiocb *iocb, struct io_event *res);
+       struct io_event res;
        struct kioctx *ctx;
        struct kiocb *kiocb;
        u32 key;
@@ -1431,32 +1448,22 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
                return -EINVAL;
 
        spin_lock_irq(&ctx->ctx_lock);
-       ret = -EAGAIN;
+
        kiocb = lookup_kiocb(ctx, iocb, key);
-       if (kiocb && kiocb->ki_cancel) {
-               cancel = kiocb->ki_cancel;
-               kiocb->ki_users ++;
-               kiocbSetCancelled(kiocb);
-       } else
-               cancel = NULL;
+       if (kiocb)
+               ret = kiocb_cancel(ctx, kiocb, &res);
+       else
+               ret = -EINVAL;
+
        spin_unlock_irq(&ctx->ctx_lock);
 
-       if (NULL != cancel) {
-               struct io_event tmp;
-               pr_debug("calling cancel\n");
-               memset(&tmp, 0, sizeof(tmp));
-               tmp.obj = (u64)(unsigned long)kiocb->ki_obj.user;
-               tmp.data = kiocb->ki_user_data;
-               ret = cancel(kiocb, &tmp);
-               if (!ret) {
-                       /* Cancellation succeeded -- copy the result
-                        * into the user's buffer.
-                        */
-                       if (copy_to_user(result, &tmp, sizeof(tmp)))
-                               ret = -EFAULT;
-               }
-       } else
-               ret = -EINVAL;
+       if (!ret) {
+               /* Cancellation succeeded -- copy the result
+                * into the user's buffer.
+                */
+               if (copy_to_user(result, &res, sizeof(res)))
+                       ret = -EFAULT;
+       }
 
        put_ioctx(ctx);