From be614086a4aff163d5aa0dc160638d1193b59cde Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 8 Feb 2008 04:18:30 -0800 Subject: [PATCH] proc: implement proc_single_file_operations Currently many /proc/pid files use a crufty precursor to the current seq_file api, and they don't have direct access to the pid_namespace or the pid of for which they are displaying data. So implement proc_single_file_operations to make the seq_file routines easy to use, and to give access to the full state of the pid of we are displaying data for. Signed-off-by: Eric W. Biederman Cc: Oleg Nesterov Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/base.c | 43 +++++++++++++++++++++++++++++++++++++++++ include/linux/proc_fs.h | 3 +++ 2 files changed, 46 insertions(+) diff --git a/fs/proc/base.c b/fs/proc/base.c index c59852b387..f4b1e14bd9 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -121,6 +121,10 @@ struct pid_entry { NOD(NAME, (S_IFREG|(MODE)), \ NULL, &proc_info_file_operations, \ { .proc_read = &proc_##OTYPE } ) +#define ONE(NAME, MODE, OTYPE) \ + NOD(NAME, (S_IFREG|(MODE)), \ + NULL, &proc_single_file_operations, \ + { .proc_show = &proc_##OTYPE } ) int maps_protect; EXPORT_SYMBOL(maps_protect); @@ -658,6 +662,45 @@ static const struct file_operations proc_info_file_operations = { .read = proc_info_read, }; +static int proc_single_show(struct seq_file *m, void *v) +{ + struct inode *inode = m->private; + struct pid_namespace *ns; + struct pid *pid; + struct task_struct *task; + int ret; + + ns = inode->i_sb->s_fs_info; + pid = proc_pid(inode); + task = get_pid_task(pid, PIDTYPE_PID); + if (!task) + return -ESRCH; + + ret = PROC_I(inode)->op.proc_show(m, ns, pid, task); + + put_task_struct(task); + return ret; +} + +static int proc_single_open(struct inode *inode, struct file *filp) +{ + int ret; + ret = single_open(filp, proc_single_show, NULL); + if (!ret) { + struct seq_file *m = filp->private_data; + + m->private = inode; + } + return ret; +} + +static const struct file_operations proc_single_file_operations = { + .open = proc_single_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static int mem_open(struct inode* inode, struct file* file) { file->private_data = (void*)((long)current->self_exec_id); diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index e435515168..b04ebf09fb 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -262,6 +262,9 @@ extern void kclist_add(struct kcore_list *, void *, size_t); union proc_op { int (*proc_get_link)(struct inode *, struct dentry **, struct vfsmount **); int (*proc_read)(struct task_struct *task, char *page); + int (*proc_show)(struct seq_file *m, + struct pid_namespace *ns, struct pid *pid, + struct task_struct *task); }; struct proc_inode { -- 2.39.5