2012-11-14 15:22:53

by Cyrill Gorcunov

Subject: [patch 1/7] 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 <[email protected]>
CC: Pavel Emelyanov <[email protected]>
CC: Oleg Nesterov <[email protected]>
CC: Andrey Vagin <[email protected]>
CC: Al Viro <[email protected]>
CC: Alexey Dobriyan <[email protected]>
CC: Andrew Morton <[email protected]>
CC: James Bottomley <[email protected]>
CC: "Aneesh Kumar K.V" <[email protected]>
CC: Alexey Dobriyan <[email protected]>
CC: Matthew Helsley <[email protected]>
CC: "J. Bruce Fields" <[email protected]>
CC: "Aneesh Kumar K.V" <[email protected]>
CC: Tvrtko Ursulin <[email protected]>
---
fs/proc/fd.c | 2 ++
include/linux/fs.h | 4 ++--
2 files changed, 4 insertions(+), 2 deletions(-)

Index: linux-2.6.git/fs/proc/fd.c
===================================================================
--- linux-2.6.git.orig/fs/proc/fd.c
+++ linux-2.6.git/fs/proc/fd.c
@@ -50,6 +50,8 @@ static int seq_show(struct seq_file *m,
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);
}

Index: linux-2.6.git/include/linux/fs.h
===================================================================
--- linux-2.6.git.orig/include/linux/fs.h
+++ linux-2.6.git/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);
@@ -1545,6 +1546,7 @@ 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 {
@@ -1580,8 +1582,6 @@ 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,

2012-11-15 13:49:45

by Pavel Emelyanov

Subject: Re: [patch 1/7] 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 <[email protected]>
> CC: Pavel Emelyanov <[email protected]>
> CC: Oleg Nesterov <[email protected]>
> CC: Andrey Vagin <[email protected]>
> CC: Al Viro <[email protected]>
> CC: Alexey Dobriyan <[email protected]>
> CC: Andrew Morton <[email protected]>
> CC: James Bottomley <[email protected]>
> CC: "Aneesh Kumar K.V" <[email protected]>
> CC: Alexey Dobriyan <[email protected]>
> CC: Matthew Helsley <[email protected]>
> CC: "J. Bruce Fields" <[email protected]>
> CC: "Aneesh Kumar K.V" <[email protected]>
> CC: Tvrtko Ursulin <[email protected]>
> ---
> fs/proc/fd.c | 2 ++
> include/linux/fs.h | 4 ++--
> 2 files changed, 4 insertions(+), 2 deletions(-)

Acked-by: Pavel Emelyanov <[email protected]>