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-rw-r--r--include/linux/aio.h201
1 files changed, 201 insertions, 0 deletions
diff --git a/include/linux/aio.h b/include/linux/aio.h
new file mode 100644
index 000000000000..a4d5af907f90
--- /dev/null
+++ b/include/linux/aio.h
@@ -0,0 +1,201 @@
+#ifndef __LINUX__AIO_H
+#define __LINUX__AIO_H
+
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/aio_abi.h>
+
+#include <asm/atomic.h>
+
+#define AIO_MAXSEGS 4
+#define AIO_KIOGRP_NR_ATOMIC 8
+
+struct kioctx;
+
+/* Notes on cancelling a kiocb:
+ * If a kiocb is cancelled, aio_complete may return 0 to indicate
+ * that cancel has not yet disposed of the kiocb. All cancel
+ * operations *must* call aio_put_req to dispose of the kiocb
+ * to guard against races with the completion code.
+ */
+#define KIOCB_C_CANCELLED 0x01
+#define KIOCB_C_COMPLETE 0x02
+
+#define KIOCB_SYNC_KEY (~0U)
+
+/* ki_flags bits */
+#define KIF_LOCKED 0
+#define KIF_KICKED 1
+#define KIF_CANCELLED 2
+
+#define kiocbTryLock(iocb) test_and_set_bit(KIF_LOCKED, &(iocb)->ki_flags)
+#define kiocbTryKick(iocb) test_and_set_bit(KIF_KICKED, &(iocb)->ki_flags)
+
+#define kiocbSetLocked(iocb) set_bit(KIF_LOCKED, &(iocb)->ki_flags)
+#define kiocbSetKicked(iocb) set_bit(KIF_KICKED, &(iocb)->ki_flags)
+#define kiocbSetCancelled(iocb) set_bit(KIF_CANCELLED, &(iocb)->ki_flags)
+
+#define kiocbClearLocked(iocb) clear_bit(KIF_LOCKED, &(iocb)->ki_flags)
+#define kiocbClearKicked(iocb) clear_bit(KIF_KICKED, &(iocb)->ki_flags)
+#define kiocbClearCancelled(iocb) clear_bit(KIF_CANCELLED, &(iocb)->ki_flags)
+
+#define kiocbIsLocked(iocb) test_bit(KIF_LOCKED, &(iocb)->ki_flags)
+#define kiocbIsKicked(iocb) test_bit(KIF_KICKED, &(iocb)->ki_flags)
+#define kiocbIsCancelled(iocb) test_bit(KIF_CANCELLED, &(iocb)->ki_flags)
+
+struct kiocb {
+ struct list_head ki_run_list;
+ long ki_flags;
+ int ki_users;
+ unsigned ki_key; /* id of this request */
+
+ struct file *ki_filp;
+ struct kioctx *ki_ctx; /* may be NULL for sync ops */
+ int (*ki_cancel)(struct kiocb *, struct io_event *);
+ 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 */
+ loff_t ki_pos;
+ /* 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;
+};
+
+#define is_sync_kiocb(iocb) ((iocb)->ki_key == KIOCB_SYNC_KEY)
+#define init_sync_kiocb(x, filp) \
+ do { \
+ struct task_struct *tsk = current; \
+ (x)->ki_flags = 0; \
+ (x)->ki_users = 1; \
+ (x)->ki_key = KIOCB_SYNC_KEY; \
+ (x)->ki_filp = (filp); \
+ (x)->ki_ctx = &tsk->active_mm->default_kioctx; \
+ (x)->ki_cancel = NULL; \
+ (x)->ki_dtor = NULL; \
+ (x)->ki_obj.tsk = tsk; \
+ (x)->ki_user_data = 0; \
+ init_wait((&(x)->ki_wait)); \
+ } while (0)
+
+#define AIO_RING_MAGIC 0xa10a10a1
+#define AIO_RING_COMPAT_FEATURES 1
+#define AIO_RING_INCOMPAT_FEATURES 0
+struct aio_ring {
+ unsigned id; /* kernel internal index number */
+ unsigned nr; /* number of io_events */
+ unsigned head;
+ unsigned tail;
+
+ unsigned magic;
+ unsigned compat_features;
+ unsigned incompat_features;
+ unsigned header_length; /* size of aio_ring */
+
+
+ struct io_event io_events[0];
+}; /* 128 bytes + ring size */
+
+#define aio_ring_avail(info, ring) (((ring)->head + (info)->nr - 1 - (ring)->tail) % (info)->nr)
+
+#define AIO_RING_PAGES 8
+struct aio_ring_info {
+ unsigned long mmap_base;
+ unsigned long mmap_size;
+
+ struct page **ring_pages;
+ spinlock_t ring_lock;
+ long nr_pages;
+
+ unsigned nr, tail;
+
+ struct page *internal_pages[AIO_RING_PAGES];
+};
+
+struct kioctx {
+ atomic_t users;
+ int dead;
+ struct mm_struct *mm;
+
+ /* This needs improving */
+ unsigned long user_id;
+ struct kioctx *next;
+
+ wait_queue_head_t wait;
+
+ spinlock_t ctx_lock;
+
+ int reqs_active;
+ struct list_head active_reqs; /* used for cancellation */
+ struct list_head run_list; /* used for kicked reqs */
+
+ unsigned max_reqs;
+
+ struct aio_ring_info ring_info;
+
+ struct work_struct wq;
+};
+
+/* prototypes */
+extern unsigned aio_max_size;
+
+extern ssize_t FASTCALL(wait_on_sync_kiocb(struct kiocb *iocb));
+extern int FASTCALL(aio_put_req(struct kiocb *iocb));
+extern void FASTCALL(kick_iocb(struct kiocb *iocb));
+extern int FASTCALL(aio_complete(struct kiocb *iocb, long res, long res2));
+extern void FASTCALL(__put_ioctx(struct kioctx *ctx));
+struct mm_struct;
+extern void FASTCALL(exit_aio(struct mm_struct *mm));
+extern struct kioctx *lookup_ioctx(unsigned long ctx_id);
+extern int FASTCALL(io_submit_one(struct kioctx *ctx,
+ struct iocb __user *user_iocb, struct iocb *iocb));
+
+/* semi private, but used by the 32bit emulations: */
+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 in_aio() !is_sync_wait(current->io_wait)
+/* may be used for debugging */
+#define warn_if_async() \
+do { \
+ if (in_aio()) { \
+ printk(KERN_ERR "%s(%s:%d) called in async context!\n", \
+ __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
+#define io_wait_to_kiocb(wait) container_of(wait, struct kiocb, ki_wait)
+#define is_retried_kiocb(iocb) ((iocb)->ki_retried > 1)
+
+#include <linux/aio_abi.h>
+
+static inline struct kiocb *list_kiocb(struct list_head *h)
+{
+ return list_entry(h, struct kiocb, ki_list);
+}
+
+/* for sysctl: */
+extern atomic_t aio_nr;
+extern unsigned aio_max_nr;
+
+#endif /* __LINUX__AIO_H */