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 CC: Pavel Emelyanov CC: Al Viro CC: Alexey Dobriyan CC: Andrew Morton CC: James Bottomley CC: "Aneesh Kumar K.V" CC: Alexey Dobriyan CC: Matthew Helsley CC: "J. Bruce Fields" CC: "Aneesh Kumar K.V" --- fs/proc/fd.c | 5 +++++ include/linux/fs.h | 3 +++ 2 files changed, 8 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 @@ -23,8 +23,13 @@ struct proc_fdinfo { static int seq_show(struct seq_file *m, void *v) { struct proc_fdinfo *fdinfo = container_of(m, struct proc_fdinfo, m); + seq_printf(m, "pos:\t%lli\nflags:\t0%o\n", (long long)fdinfo->fd_file->f_pos, fdinfo->f_flags); + + if (fdinfo->fd_file->f_op->show_fdinfo) + return fdinfo->fd_file->f_op->show_fdinfo(m, fdinfo->fd_file); + return 0; } 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 @@ -1775,6 +1775,8 @@ 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); @@ -1803,6 +1805,7 @@ 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 { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/