Contents

buf_bdwrite

Mark a buffer for delayed write.

Declaration

errno_t buf_bdwrite(buf_t bp);

Parameters

  • bp:

    The buffer to mark for delayed write.

  • return_error:

    If the number of pending delayed writes systemwide is larger than an internal limit, return EAGAIN rather than doing an asynchronous write.

Return Value

EAGAIN for return_error != 0 case, 0 for succeess, errors from buf_bawrite.

Discussion

Marks a buffer as waiting for delayed write and the current I/O as complete; data will be written to backing store before the buffer is reused, but it will not be queued for I/O immediately. Note that for buffers allocated with buf_alloc(), there are no such guarantees; you must take care of your own flushing to disk. If the number of delayed writes pending on the system is greater than an internal limit and the caller has not requested otherwise [see return_error] , buf_bdwrite() will unilaterally launch an asynchronous I/O with buf_bawrite() to keep the pile of delayed writes from getting too large.

See Also

Buffers