Lsof
Linux:判斷文件是否使用 O_SYNC 打開
有沒有辦法判斷程序是否打開了帶有 O_SYNC 標誌的文件?我在想 lsof 可能能夠做到這一點,但找不到辦法。
這可以使用
systemtap
腳本來完成。這個取自這裡,完全符合您的要求:# list_flags.stp # Copyright (C) 2007 Red Hat, Inc., Eugene Teo # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License version 2 as # published by the Free Software Foundation. # %{ #include <linux/file.h> %} function list_flags:long (pid:long, fd:long) %{ struct task_struct *p; struct list_head *_p, *_n; list_for_each_safe(_p, _n, ¤t->tasks) { p = list_entry(_p, struct task_struct, tasks); if (p->pid == (int)THIS->pid) { struct file *filp; struct files_struct *files = p->files; spin_lock(&files->file_lock); filp = fcheck_files(files, (int)THIS->fd); THIS->__retvalue = (!filp ? -1 : filp->f_flags); spin_unlock(&files->file_lock); break; } } %} probe begin { flag_str = ( (flags = list_flags($1, $2)) ? _sys_open_flag_str(flags) : "???"); printf("pid: %d, fd: %d: %s\n", $1, $2, flag_str) exit() }
參考連結中提供了兩個有關如何使用它的範例,我將在此處複製其中一個範例:
[eteo@kerndev ~]$ stap -vg list_flags.stp $$ 3 2>&1 | grep O_DIRECT pid: 30830, fd: 3: O_RDONLY|O_APPEND|O_CREAT|O_DIRECT|O_DIRECTORY|O_EXCL|O_LARGEFILE|O_NOATIME|O_NOCTTY|O_NOFOLLOW|O_NONBLOCK|O_SYNC|O_TRUNC
您可以根據自己的目的替換
O_DIRECT
為O_SYNC
。更多參考資料:
# # # #