(split) LDP man-pages の original/ を v3.29 に更新。

[linuxjm/LDP_man-pages.git] / original / man2 / sync_file_range.2

diff --git a/original/man2/sync_file_range.2 b/original/man2/sync_file_range.2
index afca9c2..2f52254 100644 (file)
--- a/original/man2/sync_file_range.2
+++ b/original/man2/sync_file_range.2
@@ -25,8 +25,9 @@
 .\"
 .\" 2006-07-05 Initial creation, Michael Kerrisk based on
 .\"     Andrew Morton's comments in fs/sync.c
+.\" 2010-10-09, mtk, Document sync_file_range2()
 .\"
-.TH SYNC_FILE_RANGE 2 2010-01-17 "Linux" "Linux Programmer's Manual"
+.TH SYNC_FILE_RANGE 2 2010-10-09 "Linux" "Linux Programmer's Manual"
 .SH NAME
 sync_file_range \- sync a file segment with disk
 .SH SYNOPSIS
@@ -179,6 +180,40 @@ appeared on Linux in kernel 2.6.17.
 .SH "CONFORMING TO"
 This system call is Linux-specific, and should be avoided
 in portable programs.
+.SH NOTES
+Some architectures (e.g., PowerPC, ARM)
+need 64-bit arguments to be aligned in a suitable pair of registers.
+.\" See kernel commit edd5cd4a9424f22b0fa08bef5e299d41befd5622
+On such architectures, the call signature of
+.BR sync_file_range ()
+is flawed, since it forces a register to be wasted as padding between the
+.I fd
+and
+.I offset
+arguments.
+Therefore, these architectures define a different
+system call that orders the arguments suitably:
+.PP
+.in +4n
+.nf
+.BI "int sync_file_range2(int " fd ", unsigned int " flags ,
+.BI "                     off64_t " offset ", off64_t " nbytes );
+.fi
+.in
+.PP
+The behavior of this system call is otherwise exactly the same as
+.BR sync_file_range().
+
+A system call with this signature first appeared on the ARM architecture
+in Linux 2.6.20, with the name
+.BR arm_sync_file_range ().
+It was renamed in Linux 2.6.22,
+when the analogous system call was added for PowerPC.
+On architectures where glibc support is provided,
+glibc transparently wraps
+.BR sync_file_range2 ()
+under the name
+.BR sync_file_range ().
 .SH "SEE ALSO"
 .BR fdatasync (2),
 .BR fsync (2),