[nginx] Adjusted file->sys_offset after the write() syscall.

[Valentin Bartenev]

details:   http://hg.nginx.org/nginx/rev/8f6d753c1953
branches:  
changeset: 6298:8f6d753c1953
user:      Valentin Bartenev <vbart at nginx.com>
date:      Tue Nov 17 19:01:41 2015 +0300
description:
Adjusted file->sys_offset after the write() syscall.

This fixes suboptimal behavior caused by surplus lseek() for sequential writes
on systems without pwrite().  A consecutive read after write might result in an
error on systems without pread() and pwrite().

Fortunately, at the moment there are no widely used systems without these
syscalls.

diffstat:

 src/os/unix/ngx_files.c |  1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diffs (11 lines):

diff -r 92482faf5d8a -r 8f6d753c1953 src/os/unix/ngx_files.c
--- a/src/os/unix/ngx_files.c	Tue Nov 17 19:01:41 2015 +0300
+++ b/src/os/unix/ngx_files.c	Tue Nov 17 19:01:41 2015 +0300
@@ -226,6 +226,7 @@ ngx_write_file(ngx_file_t *file, u_char 
             return NGX_ERROR;
         }
 
+        file->sys_offset += n;
         file->offset += n;
         written += n;