From 55985dd72ab27b47530dcc8bdddd28b69f4abe8b Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@openvz.org>
Date: Mon, 17 Dec 2012 16:04:55 -0800
Subject: [PATCH] procfs: add ability to plug in auxiliary fdinfo providers
This patch brings ability to print out auxiliary data associated with
file in procfs interface /proc/pid/fdinfo/fd.
In particular further patches make eventfd, evenpoll, signalfd and
fsnotify to print additional information complete enough to restore
these objects after checkpoint.
To simplify the code we add show_fdinfo callback inside struct
file_operations (as Al and Pavel are proposing).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/proc/fd.c | 2 ++
include/linux/fs.h | 4 ++--
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index f28a875f8779f..d7a4a28ef6302 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -50,6 +50,8 @@ static int seq_show(struct seq_file *m, void *v)
if (!ret) {
seq_printf(m, "pos:\t%lli\nflags:\t0%o\n",
(long long)file->f_pos, f_flags);
+ if (file->f_op->show_fdinfo)
+ ret = file->f_op->show_fdinfo(m, file);
fput(file);
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 029552ff774c0..5abf703d06ba8 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -44,6 +44,7 @@ struct vm_area_struct;
struct vfsmount;
struct cred;
struct swap_info_struct;
+struct seq_file;
extern void __init inode_init(void);
extern void __init inode_init_early(void);
@@ -1543,6 +1544,7 @@ struct file_operations {
int (*setlease)(struct file *, long, struct file_lock **);
long (*fallocate)(struct file *file, int mode, loff_t offset,
loff_t len);
+ int (*show_fdinfo)(struct seq_file *m, struct file *f);
};
struct inode_operations {
@@ -1578,8 +1580,6 @@ struct inode_operations {
umode_t create_mode, int *opened);
} ____cacheline_aligned;
-struct seq_file;
-
ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
unsigned long nr_segs, unsigned long fast_segs,
struct iovec *fast_pointer,
--
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