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: 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]>
---
fs/proc/fd.c | 2 ++
include/linux/fs.h | 3 +++
2 files changed, 5 insertions(+)
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
@@ -1517,6 +1517,8 @@ struct block_device_operations;
#define HAVE_COMPAT_IOCTL 1
#define HAVE_UNLOCKED_IOCTL 1
+struct seq_file;
+
struct file_operations {
struct module *owner;
loff_t (*llseek) (struct file *, loff_t, int);
@@ -1545,6 +1547,7 @@ 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 {
On Mon, 12 Nov 2012 14:14:41 +0400
Cyrill Gorcunov <[email protected]> wrote:
> 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).
>
> ...
>
> --- linux-2.6.git.orig/include/linux/fs.h
> +++ linux-2.6.git/include/linux/fs.h
> @@ -1517,6 +1517,8 @@ struct block_device_operations;
> #define HAVE_COMPAT_IOCTL 1
> #define HAVE_UNLOCKED_IOCTL 1
>
> +struct seq_file;
> +
We already have a forward declaration of seq_file in fs.h. At line
1583(!).
This is why forward declarations should always be placed at the start
of the file, please.
--- a/include/linux/fs.h~procfs-add-ability-to-plug-in-auxiliary-fdinfo-providers-fix
+++ a/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);
@@ -1517,8 +1518,6 @@ struct block_device_operations;
#define HAVE_COMPAT_IOCTL 1
#define HAVE_UNLOCKED_IOCTL 1
-struct seq_file;
-
struct file_operations {
struct module *owner;
loff_t (*llseek) (struct file *, loff_t, int);
@@ -1583,8 +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,
_
On Mon, Nov 12, 2012 at 04:40:22PM -0800, Andrew Morton wrote:
> >
> > --- linux-2.6.git.orig/include/linux/fs.h
> > +++ linux-2.6.git/include/linux/fs.h
> > @@ -1517,6 +1517,8 @@ struct block_device_operations;
> > #define HAVE_COMPAT_IOCTL 1
> > #define HAVE_UNLOCKED_IOCTL 1
> >
> > +struct seq_file;
> > +
>
> We already have a forward declaration of seq_file in fs.h. At line
> 1583(!).
>
> This is why forward declarations should always be placed at the start
> of the file, please.
Yes, thanks a lot, Andrew!
Cyrill