io_submit man page

io_submit — submit asynchronous I/O blocks for processing


#include <linux/aio_abi.h> /* Defines needed types */

int io_submit(aio_context_t ctx_id, long nr, struct iocb **iocbpp);

Note: There is no glibc wrapper for this system call; see Notes.


The io_submit() system call queues nr I/O request blocks for processing in the AIO context ctx_id. The iocbpp argument should be an array of nr AIO control blocks, which will be submitted to context ctx_id.

Return Value

On success, io_submit() returns the number of iocbs submitted (which may be 0 if nr is zero). For the failure return, see Notes.


Insufficient resources are available to queue any iocbs.
The file descriptor specified in the first iocb is invalid.
One of the data structures points to invalid data.
The AIO context specified by ctx_id is invalid. nr is less than 0. The iocb at *iocbpp[0] is not properly initialized, or the operation specified is invalid for the file descriptor in the iocb.
io_submit() is not implemented on this architecture.


The asynchronous I/O system calls first appeared in Linux 2.5.

Conforming to

io_submit() is Linux-specific and should not be used in programs that are intended to be portable.


Glibc does not provide a wrapper function for this system call. You could invoke it using syscall(2). But instead, you probably want to use the io_submit() wrapper function provided by libaio.

Note that the libaio wrapper function uses a different type (io_context_t) for the ctx_id argument. Note also that the libaio wrapper does not follow the usual C library conventions for indicating errors: on error it returns a negated error number (the negative of one of the values listed in Errors). If the system call is invoked via syscall(2), then the return value follows the usual conventions for indicating an error: -1, with errno set to a (positive) value that indicates the error.

See Also

io_cancel(2), io_destroy(2), io_getevents(2), io_setup(2), aio(7)

Referenced By

aio(7), fcntl(2), io_cancel(2), io_destroy(2), io_getevents(2), ioping(1), io_setup(2), syscalls(2).

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