aio: store event at final iocb_put()

Instead of having aio_complete() set ->ki_res.{res,res2}, do that
explicitly in its callers, drop the reference (as aio_complete()
used to do) and delay the rest until the final iocb_put().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/aio.c b/fs/aio.c
index b0a8aa544e34cb2a56ca99582d49d460cec65731..f405e2fd8e28e3ebec7052eedd42f338d1dd2ef0 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1077,16 +1077,10 @@ static inline void iocb_destroy(struct aio_kiocb *iocb)
        kmem_cache_free(kiocb_cachep, iocb);
 }
 
-static inline void iocb_put(struct aio_kiocb *iocb)
-{
-       if (refcount_dec_and_test(&iocb->ki_refcnt))
-               iocb_destroy(iocb);
-}
-
 /* aio_complete
  *     Called when the io request on the given iocb is complete.
  */
-static void aio_complete(struct aio_kiocb *iocb, long res, long res2)
+static void aio_complete(struct aio_kiocb *iocb)
 {
        struct kioctx   *ctx = iocb->ki_ctx;
        struct aio_ring *ring;
@@ -1094,8 +1088,6 @@ static void aio_complete(struct aio_kiocb *iocb, long res, long res2)
        unsigned tail, pos, head;
        unsigned long   flags;
 
-       iocb->ki_res.res = res;
-       iocb->ki_res.res2 = res2;
        /*
         * Add a completion event to the ring buffer. Must be done holding
         * ctx->completion_lock to prevent other code from messing with the tail
@@ -1161,7 +1153,14 @@ static void aio_complete(struct aio_kiocb *iocb, long res, long res2)
 
        if (waitqueue_active(&ctx->wait))
                wake_up(&ctx->wait);
-       iocb_put(iocb);
+}
+
+static inline void iocb_put(struct aio_kiocb *iocb)
+{
+       if (refcount_dec_and_test(&iocb->ki_refcnt)) {
+               aio_complete(iocb);
+               iocb_destroy(iocb);
+       }
 }
 
 /* aio_read_events_ring
@@ -1435,7 +1434,9 @@ static void aio_complete_rw(struct kiocb *kiocb, long res, long res2)
                file_end_write(kiocb->ki_filp);
        }
 
-       aio_complete(iocb, res, res2);
+       iocb->ki_res.res = res;
+       iocb->ki_res.res2 = res2;
+       iocb_put(iocb);
 }
 
 static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
@@ -1583,11 +1584,10 @@ static ssize_t aio_write(struct kiocb *req, const struct iocb *iocb,
 
 static void aio_fsync_work(struct work_struct *work)
 {
-       struct fsync_iocb *req = container_of(work, struct fsync_iocb, work);
-       int ret;
+       struct aio_kiocb *iocb = container_of(work, struct aio_kiocb, fsync.work);
 
-       ret = vfs_fsync(req->file, req->datasync);
-       aio_complete(container_of(req, struct aio_kiocb, fsync), ret, 0);
+       iocb->ki_res.res = vfs_fsync(iocb->fsync.file, iocb->fsync.datasync);
+       iocb_put(iocb);
 }
 
 static int aio_fsync(struct fsync_iocb *req, const struct iocb *iocb,
@@ -1608,7 +1608,8 @@ static int aio_fsync(struct fsync_iocb *req, const struct iocb *iocb,
 
 static inline void aio_poll_complete(struct aio_kiocb *iocb, __poll_t mask)
 {
-       aio_complete(iocb, mangle_poll(mask), 0);
+       iocb->ki_res.res = mangle_poll(mask);
+       iocb_put(iocb);
 }
 
 static void aio_poll_complete_work(struct work_struct *work)