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</o:shapelayout></xml><![endif]--></head><body lang=ZH-CN link=blue vlink=purple style='text-justify-trim:punctuation'><div class=WordSection1><p class=MsoNormal><span lang=EN-US>This might be a question asked before, but I just couldn’t effectively search the whole archives,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>So please bear me and kindly advise.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>We have a 3<sup>rd</sup> party application (video streaming kind of) which uses directIO (O_DIRECT).<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>On the server side, in the posix translator, we added the “</span><span lang=EN-US style='font-size:12.0pt;font-family:SimSun;color:black'>option o-direct enable”</span><span lang=EN-US> <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>On the client side, we mounted as “mount -t glusterfs -o direct-io-mode=enable server1:/test-volume /mnt/glusterfs”<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>But the application still fails with error (cannot create/open file with O_DIRECT).<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Then we trace to the fuse module in the kernel, which has following checking:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal align=left style='text-align:left'><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:#314344'>int fuse_open_common(struct inode *inode, struct file *file, bool isdir)</span><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:navy'><o:p></o:p></span></p><p class=MsoNormal align=left style='text-align:left'><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:#314344'>{</span><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:navy'><o:p></o:p></span></p><p class=MsoNormal align=left style='text-align:left'><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:#314344'> struct fuse_conn *fc = get_fuse_conn(inode);</span><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:navy'><o:p></o:p></span></p><p class=MsoNormal align=left style='text-align:left'><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:#314344'> int err;</span><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:navy'><o:p></o:p></span></p><p class=MsoNormal align=left style='text-align:left'><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:#314344'> /* VFS checks this, but only _after_ ->open() */</span><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:navy'><o:p></o:p></span></p><p class=MsoNormal align=left style='text-align:left'><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:red'> <strong><span style='font-family:"Verdana","sans-serif"'> if (file->f_flags & O_DIRECT)</span></strong></span><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:navy'><o:p></o:p></span></p><p class=MsoNormal align=left style='text-align:left'><strong><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:red'> return -EINVAL;</span></strong><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:navy'><o:p></o:p></span></p><p class=MsoNormal align=left style='text-align:left'><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:#314344'> err = generic_file_open(inode, file);</span><span lang=EN-US style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:navy'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>looks like regardless what we configure on the gluster side, the FUSE still rejects the O_DIRECT.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Could someone shed light ? we’re also trying to take out the O_DIRECT checking in FUSE module,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>to see what will happen, will report soon.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Bill Bao<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></body></html>