Add aio_writev and aio_readv

POSIX AIO is great, but it lacks vectored I/O functions. This commit fixes that shortcoming by adding aio_writev and aio_readv. They aren't part of the standard, but they're an obvious extension. They work just like their synchronous equivalents pwritev and preadv. It isn't yet possible to use vectored aiocbs with lio_listio, but that could be added in the future. Reviewed by: jhb, kib, bcr Relnotes: yes Differential Revision: https://reviews.freebsd.org/D27743
freebsd · Jan 3, 2021 · 022ca2f · 022ca2f
1 parent 486580c
commit 022ca2f
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Showing 17 changed files with 1,171 additions and 292 deletions.
diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc
@@ -354,6 +354,8 @@ MAN+=	sctp_generic_recvmsg.2 \
 	write.2 \
 	_umtx_op.2
 
+MLINKS+=aio_read.2 aio_readv.2
+MLINKS+=aio_write.2 aio_writev.2
 MLINKS+=accept.2 accept4.2
 MLINKS+=access.2 eaccess.2 \
 	access.2 faccessat.2

diff --git a/lib/libc/sys/Symbol.map b/lib/libc/sys/Symbol.map
@@ -403,6 +403,8 @@ FBSD_1.5 {
 
 FBSD_1.6 {
 	__sysctlbyname;
+	aio_readv;
+	aio_writev;
 	close_range;
 	copy_file_range;
 	fhlink;

diff --git a/lib/libc/sys/aio_error.2 b/lib/libc/sys/aio_error.2
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 2, 1999
+.Dd January 2, 2021
 .Dt AIO_ERROR 2
 .Os
 .Sh NAME
@@ -52,7 +52,9 @@ is returned.
 If the request has completed unsuccessfully the error
 status is returned as described in
 .Xr read 2 ,
+.Xr readv 2 ,
 .Xr write 2 ,
+.Xr writev 2 ,
 or
 .Xr fsync 2 .
 On failure,
@@ -76,9 +78,11 @@ does not reference an outstanding asynchronous I/O request.
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_read 2 ,
+.Xr aio_readv 2 ,
 .Xr aio_return 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_write 2 ,
+.Xr aio_writev 2 ,
 .Xr fsync 2 ,
 .Xr read 2 ,
 .Xr write 2 ,

diff --git a/lib/libc/sys/aio_read.2 b/lib/libc/sys/aio_read.2
@@ -24,33 +24,55 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 19, 2016
+.Dd January 2, 2021
 .Dt AIO_READ 2
 .Os
 .Sh NAME
-.Nm aio_read
+.Nm aio_read ,
+.Nm aio_readv
 .Nd asynchronous read from a file (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_read "struct aiocb *iocb"
+.In sys/uio.h
+.Ft int
+.Fn aio_readv "struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_read
-system call allows the calling process to read
-.Fa iocb->aio_nbytes
+and
+.Fn aio_readv
+system calls allow the calling process to read
 from the descriptor
 .Fa iocb->aio_fildes
 beginning at the offset
-.Fa iocb->aio_offset
-into the buffer pointed to by
-.Fa iocb->aio_buf .
-The call returns immediately after the read request has
+.Fa iocb->aio_offset .
+.Fn aio_read
+will read
+.Fa iocb->aio_nbytes
+from the buffer pointed to by
+.Fa iocb->aio_buf ,
+whereas
+.Fn aio_readv
+reads the data into the
+.Fa iocb->aio_iovcnt
+buffers specified by the members of the
+.Fa iocb->aio_iov
+array.
+Both syscalls return immediately after the read request has
 been enqueued to the descriptor; the read may or may not have
 completed at the time the call returns.
 .Pp
+For
+.Fn aio_readv
+the
+.Fa iovec
+structure is defined in
+.Xr readv 2 .
+.Pp
 If _POSIX_PRIORITIZED_IO is defined, and the descriptor supports it,
 then the enqueued operation is submitted at a priority equal to that
 of the calling process minus
@@ -61,7 +83,9 @@ The
 argument
 is ignored by the
 .Fn aio_read
-system call.
+and
+.Fn aio_readv
+system calls.
 .Pp
 The
 .Fa iocb
@@ -108,16 +132,22 @@ is past the offset maximum for
 .Fa iocb->aio_fildes ,
 no I/O will occur.
 .Sh RETURN VALUES
-.Rv -std aio_read
+.Rv -std aio_read aio_readv
 .Sh DIAGNOSTICS
 None.
 .Sh ERRORS
 The
 .Fn aio_read
-system call will fail if:
+and
+.Fn aio_readv
+system calls will fail if:
 .Bl -tag -width Er
 .It Bq Er EAGAIN
 The request was not queued because of system resource limitations.
+.It Bq Er EFAULT
+Part of
+.Fa aio_iov
+points outside the process's allocated address space.
 .It Bq Er EINVAL
 The asynchronous notification method in
 .Fa iocb->aio_sigevent.sigev_notify
@@ -130,10 +160,14 @@ are unsafe and unsafe asynchronous I/O operations are disabled.
 .Pp
 The following conditions may be synchronously detected when the
 .Fn aio_read
+or
+.Fn aio_readv
 system call is made, or asynchronously, at any time thereafter.
 If they
 are detected at call time,
 .Fn aio_read
+or
+.Fn aio_readv
 returns -1 and sets
 .Va errno
 appropriately; otherwise the
@@ -207,11 +241,18 @@ The
 system call is expected to conform to the
 .St -p1003.1
 standard.
+The
+.Fn aio_readv
+system call is a FreeBSD extension, and should not be used in portable code.
 .Sh HISTORY
 The
 .Fn aio_read
 system call first appeared in
 .Fx 3.0 .
+The
+.Fn aio_readv
+system call first appeared in
+.Fx 13.0 .
 .Sh AUTHORS
 This
 manual page was written by

diff --git a/lib/libc/sys/aio_return.2 b/lib/libc/sys/aio_return.2
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 21, 2016
+.Dd January 2, 2021
 .Dt AIO_RETURN 2
 .Os
 .Sh NAME
@@ -55,7 +55,9 @@ returns something other than
 If the asynchronous I/O request has completed, the status is returned
 as described in
 .Xr read 2 ,
+.Xr readv 2 ,
 .Xr write 2 ,
+.Xr writev 2 ,
 or
 .Xr fsync 2 .
 Otherwise,

diff --git a/lib/libc/sys/aio_write.2 b/lib/libc/sys/aio_write.2
@@ -24,40 +24,61 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 19, 2016
+.Dd January 2, 2021
 .Dt AIO_WRITE 2
 .Os
 .Sh NAME
-.Nm aio_write
+.Nm aio_write ,
+.Nm aio_writev
 .Nd asynchronous write to a file (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_write "struct aiocb *iocb"
+.In sys/uio.h
+.Ft int
+.Fn aio_writev "struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_write
-system call allows the calling process to write
-.Fa iocb->aio_nbytes
-from the buffer pointed to by
-.Fa iocb->aio_buf
+and
+.Fn aio_writev
+system calls allow the calling process to write
 to the descriptor
 .Fa iocb->aio_fildes .
-The call returns immediately after the write request has been enqueued
+.Fn aio_write
+will write
+.Fa iocb->aio_nbytes
+from the buffer pointed to by
+.Fa iocb->aio_buf ,
+whereas
+.Fn aio_writev
+gathers the data from the
+.Fa iocb->aio_iovcnt
+buffers specified by the members of the
+.Fa iocb->aio_iov
+array.
+Both syscalls return immediately after the write request has been enqueued
 to the descriptor; the write may or may not have completed at the time
 the call returns.
 If the request could not be enqueued, generally due
 to invalid arguments, the call returns without having enqueued the
 request.
 .Pp
+For
+.Fn aio_writev
+the
+.Fa iovec
+structure is defined in
+.Xr writev 2 .
+.Pp
 If
 .Dv O_APPEND
 is set for
 .Fa iocb->aio_fildes ,
-.Fn aio_write
-operations append to the file in the same order as the calls were
+write operations append to the file in the same order as the calls were
 made.
 If
 .Dv O_APPEND
@@ -103,6 +124,8 @@ The asynchronous I/O control buffer
 .Fa iocb
 should be zeroed before the
 .Fn aio_write
+or
+.Fn aio_writev
 system call to avoid passing bogus context information to the kernel.
 .Pp
 Modifications of the Asynchronous I/O Control Block structure or the
@@ -114,14 +137,20 @@ is past the offset maximum for
 .Fa iocb->aio_fildes ,
 no I/O will occur.
 .Sh RETURN VALUES
-.Rv -std aio_write
+.Rv -std aio_write aio_writev
 .Sh ERRORS
 The
 .Fn aio_write
-system call will fail if:
+and
+.Fn aio_writev
+system calls will fail if:
 .Bl -tag -width Er
 .It Bq Er EAGAIN
 The request was not queued because of system resource limitations.
+.It Bq Er EFAULT
+Part of
+.Fa aio_iov
+points outside the process's allocated address space.
 .It Bq Er EINVAL
 The asynchronous notification method in
 .Fa iocb->aio_sigevent.sigev_notify
@@ -134,10 +163,14 @@ are unsafe and unsafe asynchronous I/O operations are disabled.
 .Pp
 The following conditions may be synchronously detected when the
 .Fn aio_write
+or
+.Fn aio_writev
 system call is made, or asynchronously, at any time thereafter.
 If they
 are detected at call time,
 .Fn aio_write
+or
+.Fn aio_writev
 returns -1 and sets
 .Va errno
 appropriately; otherwise the
@@ -203,11 +236,19 @@ system call
 is expected to conform to the
 .St -p1003.1
 standard.
+.Pp
+The
+.Fn aio_writev
+system call is a FreeBSD extension, and should not be used in portable code.
 .Sh HISTORY
 The
 .Fn aio_write
 system call first appeared in
 .Fx 3.0 .
+The
+.Fn aio_writev
+system call first appeared in
+.Fx 13.0 .
 .Sh AUTHORS
 This manual page was written by
 .An Wes Peters Aq Mt wes@softweyr.com .

diff --git a/share/man/man4/aio.4 b/share/man/man4/aio.4
@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 22, 2017
+.Dd January 2, 2021
 .Dt AIO 4
 .Os
 .Sh NAME
@@ -215,10 +215,12 @@ as described in
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
 .Xr aio_read 2 ,
+.Xr aio_readv 2 ,
 .Xr aio_return 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_waitcomplete 2 ,
 .Xr aio_write 2 ,
+.Xr aio_writev 2 ,
 .Xr lio_listio 2 ,
 .Xr sigevent 3 ,
 .Xr sysctl 8

diff --git a/sys/bsm/audit_kevents.h b/sys/bsm/audit_kevents.h
@@ -660,6 +660,8 @@
 #define	AUE_REALPATHAT		43264	/* FreeBSD-specific. */
 #define	AUE_CLOSERANGE		43265	/* FreeBSD-specific. */
 #define	AUE_SPECIALFD		43266	/* FreeBSD-specific. */
+#define	AUE_AIO_WRITEV		43267	/* FreeBSD-specific. */
+#define	AUE_AIO_READV		43268	/* FreeBSD-specific. */
 
 /*
  * Darwin BSM uses a number of AUE_O_* definitions, which are aliased to the

diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
@@ -1070,7 +1070,7 @@ freebsd32_ptrace(struct thread *td, struct freebsd32_ptrace_args *uap)
 	return (error);
 }
 
-static int
+int
 freebsd32_copyinuio(struct iovec32 *iovp, u_int iovcnt, struct uio **uiop)
 {
 	struct iovec32 iov32;

diff --git a/sys/compat/freebsd32/freebsd32_util.h b/sys/compat/freebsd32/freebsd32_util.h
@@ -116,6 +116,8 @@ int	freebsd32_copyout_strings(struct image_params *imgp,
 	    uintptr_t *stack_base);
 int	freebsd32_copyiniov(struct iovec32 *iovp, u_int iovcnt,
 	    struct iovec **iov, int error);
+int	freebsd32_copyinuio(struct iovec32 *iovp, u_int iovcnt,
+	    struct uio **uiop);
 void	freebsd32_rusage_out(const struct rusage *s, struct rusage32 *s32);
 
 struct image_args;