From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753539AbZBSSVG (ORCPT ); Thu, 19 Feb 2009 13:21:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754440AbZBSSUT (ORCPT ); Thu, 19 Feb 2009 13:20:19 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:52630 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753678AbZBSSUO (ORCPT ); Thu, 19 Feb 2009 13:20:14 -0500 Subject: [RFC][PATCH 2/5] file c/r: expose functions to query fs support To: Ingo Molnar Cc: containers , "linux-kernel@vger.kernel.org" , "Serge E. Hallyn" , Oren Laadan , Alexey Dobriyan , Dave Hansen From: Dave Hansen Date: Thu, 19 Feb 2009 10:20:08 -0800 References: <20090219182007.B4B47C1F@kernel> In-Reply-To: <20090219182007.B4B47C1F@kernel> Message-Id: <20090219182008.8F45CD7E@kernel> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This pair of functions will check to see whether a given 'struct file' can be checkpointed. If it can't be, the "explain" function can also give a description why. Signed-off-by: Dave Hansen --- linux-2.6.git-dave/checkpoint/ckpt_file.c | 30 ++++++++++++++++++++++++++ linux-2.6.git-dave/include/linux/checkpoint.h | 18 +++++++++++++++ 2 files changed, 48 insertions(+) diff -puN checkpoint/ckpt_file.c~cr-explain-unckpt-file checkpoint/ckpt_file.c --- linux-2.6.git/checkpoint/ckpt_file.c~cr-explain-unckpt-file 2009-02-19 10:17:24.000000000 -0800 +++ linux-2.6.git-dave/checkpoint/ckpt_file.c 2009-02-19 10:17:24.000000000 -0800 @@ -72,6 +72,36 @@ int cr_scan_fds(struct files_struct *fil return n; } +int cr_explain_file(struct file *file, char *explain, int left) +{ + struct inode *inode = file->f_dentry->d_inode; + struct file_system_type *fs_type = inode->i_sb->s_type; + + if (!(fs_type->fs_flags & FS_CHECKPOINTABLE)) + return snprintf(explain, left, + " (%s does not support checkpoint)", + fs_type->name); + + if (special_file(inode->i_mode)) + return snprintf(explain, left, " (special file)"); + + return 0; +} + +int cr_file_supported(struct file *file) +{ + struct inode *inode = file->f_dentry->d_inode; + struct file_system_type *fs_type = inode->i_sb->s_type; + + if (!(fs_type->fs_flags & FS_CHECKPOINTABLE)) + return 0; + + if (special_file(inode->i_mode)) + return 0; + + return 1; +} + /* cr_write_fd_data - dump the state of a given file pointer */ static int cr_write_fd_data(struct cr_ctx *ctx, struct file *file, int parent) { diff -puN include/linux/checkpoint.h~cr-explain-unckpt-file include/linux/checkpoint.h --- linux-2.6.git/include/linux/checkpoint.h~cr-explain-unckpt-file 2009-02-19 10:17:24.000000000 -0800 +++ linux-2.6.git-dave/include/linux/checkpoint.h 2009-02-19 10:17:24.000000000 -0800 @@ -13,6 +13,8 @@ #include #include +#ifdef CONFIG_CHECKPOINT_RESTART + #define CR_VERSION 2 struct cr_ctx { @@ -99,4 +101,20 @@ extern int cr_read_files(struct cr_ctx * #define pr_fmt(fmt) "[%d:c/r:%s] " fmt, task_pid_vnr(current), __func__ +int cr_explain_file(struct file *file, char *explain, int left); +int cr_file_supported(struct file *file); + +#else + +static inline int cr_explain_file(struct file *file, char *explain, int left) +{ + return 0; +} + +int cr_file_supported(struct file *file) +{ + return 0; +} + +#endif #endif /* _CHECKPOINT_CKPT_H_ */ _