[PATCH] Remove BUG_ON(unlikely) in include/linux/aio.h
[linux-2.6.git] / include / linux / aio.h
index 60def65..8a01933 100644 (file)
@@ -24,7 +24,12 @@ struct kioctx;
 #define KIOCB_SYNC_KEY         (~0U)
 
 /* ki_flags bits */
-#define KIF_LOCKED             0
+/*
+ * This may be used for cancel/retry serialization in the future, but
+ * for now it's unused and we probably don't want modules to even
+ * think they can use it.
+ */
+/* #define KIF_LOCKED          0 */
 #define KIF_KICKED             1
 #define KIF_CANCELLED          2
 
@@ -89,26 +94,27 @@ struct kiocb {
        ssize_t                 (*ki_retry)(struct kiocb *);
        void                    (*ki_dtor)(struct kiocb *);
 
-       struct list_head        ki_list;        /* the aio core uses this
-                                                * for cancellation */
-
        union {
                void __user             *user;
                struct task_struct      *tsk;
        } ki_obj;
+
        __u64                   ki_user_data;   /* user's data for completion */
+       wait_queue_t            ki_wait;
        loff_t                  ki_pos;
+
+       void                    *private;
        /* State that we remember to be able to restart/retry  */
        unsigned short          ki_opcode;
        size_t                  ki_nbytes;      /* copy of iocb->aio_nbytes */
        char                    __user *ki_buf; /* remaining iocb->aio_buf */
        size_t                  ki_left;        /* remaining bytes */
-       wait_queue_t            ki_wait;
        long                    ki_retried;     /* just for testing */
        long                    ki_kicked;      /* just for testing */
        long                    ki_queued;      /* just for testing */
 
-       void                    *private;
+       struct list_head        ki_list;        /* the aio core uses this
+                                                * for cancellation */
 };
 
 #define is_sync_kiocb(iocb)    ((iocb)->ki_key == KIOCB_SYNC_KEY)
@@ -119,8 +125,9 @@ struct kiocb {
                (x)->ki_users = 1;                      \
                (x)->ki_key = KIOCB_SYNC_KEY;           \
                (x)->ki_filp = (filp);                  \
-               (x)->ki_ctx = &tsk->active_mm->default_kioctx;  \
+               (x)->ki_ctx = NULL;                     \
                (x)->ki_cancel = NULL;                  \
+               (x)->ki_retry = NULL;                   \
                (x)->ki_dtor = NULL;                    \
                (x)->ki_obj.tsk = tsk;                  \
                (x)->ki_user_data = 0;                  \
@@ -178,6 +185,7 @@ struct kioctx {
        struct list_head        active_reqs;    /* used for cancellation */
        struct list_head        run_list;       /* used for kicked reqs */
 
+       /* sys_io_setup currently limits this to an unsigned int */
        unsigned                max_reqs;
 
        struct aio_ring_info    ring_info;
@@ -204,8 +212,15 @@ struct kioctx *lookup_ioctx(unsigned long ctx_id);
 int FASTCALL(io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
                                  struct iocb *iocb));
 
-#define get_ioctx(kioctx)      do { if (unlikely(atomic_read(&(kioctx)->users) <= 0)) BUG(); atomic_inc(&(kioctx)->users); } while (0)
-#define put_ioctx(kioctx)      do { if (unlikely(atomic_dec_and_test(&(kioctx)->users))) __put_ioctx(kioctx); else if (unlikely(atomic_read(&(kioctx)->users) < 0)) BUG(); } while (0)
+#define get_ioctx(kioctx) do {                                         \
+       BUG_ON(atomic_read(&(kioctx)->users) <= 0);                     \
+       atomic_inc(&(kioctx)->users);                                   \
+} while (0)
+#define put_ioctx(kioctx) do {                                         \
+       BUG_ON(atomic_read(&(kioctx)->users) <= 0);                     \
+       if (unlikely(atomic_dec_and_test(&(kioctx)->users)))            \
+               __put_ioctx(kioctx);                                    \
+} while (0)
 
 #define in_aio() !is_sync_wait(current->io_wait)
 /* may be used for debugging */
@@ -229,7 +244,7 @@ static inline struct kiocb *list_kiocb(struct list_head *h)
 }
 
 /* for sysctl: */
-extern atomic_t aio_nr;
-extern unsigned aio_max_nr;
+extern unsigned long aio_nr;
+extern unsigned long aio_max_nr;
 
 #endif /* __LINUX__AIO_H */